mirror of https://git.ffmpeg.org/ffmpeg.git
19090 lines
507 KiB
Plaintext
19090 lines
507 KiB
Plaintext
@chapter Filtering Introduction
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@c man begin FILTERING INTRODUCTION
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Filtering in FFmpeg is enabled through the libavfilter library.
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In libavfilter, a filter can have multiple inputs and multiple
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outputs.
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To illustrate the sorts of things that are possible, we consider the
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following filtergraph.
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@verbatim
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[main]
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input --> split ---------------------> overlay --> output
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| ^
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|[tmp] [flip]|
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+-----> crop --> vflip -------+
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@end verbatim
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This filtergraph splits the input stream in two streams, then sends one
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stream through the crop filter and the vflip filter, before merging it
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back with the other stream by overlaying it on top. You can use the
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following command to achieve this:
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@example
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ffmpeg -i INPUT -vf "split [main][tmp]; [tmp] crop=iw:ih/2:0:0, vflip [flip]; [main][flip] overlay=0:H/2" OUTPUT
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@end example
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The result will be that the top half of the video is mirrored
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onto the bottom half of the output video.
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Filters in the same linear chain are separated by commas, and distinct
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linear chains of filters are separated by semicolons. In our example,
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@var{crop,vflip} are in one linear chain, @var{split} and
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@var{overlay} are separately in another. The points where the linear
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chains join are labelled by names enclosed in square brackets. In the
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example, the split filter generates two outputs that are associated to
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the labels @var{[main]} and @var{[tmp]}.
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The stream sent to the second output of @var{split}, labelled as
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@var{[tmp]}, is processed through the @var{crop} filter, which crops
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away the lower half part of the video, and then vertically flipped. The
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@var{overlay} filter takes in input the first unchanged output of the
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split filter (which was labelled as @var{[main]}), and overlay on its
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lower half the output generated by the @var{crop,vflip} filterchain.
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Some filters take in input a list of parameters: they are specified
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after the filter name and an equal sign, and are separated from each other
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by a colon.
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There exist so-called @var{source filters} that do not have an
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audio/video input, and @var{sink filters} that will not have audio/video
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output.
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@c man end FILTERING INTRODUCTION
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@chapter graph2dot
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@c man begin GRAPH2DOT
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The @file{graph2dot} program included in the FFmpeg @file{tools}
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directory can be used to parse a filtergraph description and issue a
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corresponding textual representation in the dot language.
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Invoke the command:
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@example
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graph2dot -h
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@end example
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to see how to use @file{graph2dot}.
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You can then pass the dot description to the @file{dot} program (from
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the graphviz suite of programs) and obtain a graphical representation
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of the filtergraph.
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For example the sequence of commands:
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@example
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echo @var{GRAPH_DESCRIPTION} | \
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tools/graph2dot -o graph.tmp && \
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dot -Tpng graph.tmp -o graph.png && \
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display graph.png
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@end example
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can be used to create and display an image representing the graph
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described by the @var{GRAPH_DESCRIPTION} string. Note that this string must be
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a complete self-contained graph, with its inputs and outputs explicitly defined.
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For example if your command line is of the form:
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@example
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ffmpeg -i infile -vf scale=640:360 outfile
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@end example
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your @var{GRAPH_DESCRIPTION} string will need to be of the form:
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@example
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nullsrc,scale=640:360,nullsink
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@end example
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you may also need to set the @var{nullsrc} parameters and add a @var{format}
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filter in order to simulate a specific input file.
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@c man end GRAPH2DOT
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@chapter Filtergraph description
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@c man begin FILTERGRAPH DESCRIPTION
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A filtergraph is a directed graph of connected filters. It can contain
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cycles, and there can be multiple links between a pair of
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filters. Each link has one input pad on one side connecting it to one
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filter from which it takes its input, and one output pad on the other
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side connecting it to one filter accepting its output.
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Each filter in a filtergraph is an instance of a filter class
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registered in the application, which defines the features and the
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number of input and output pads of the filter.
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A filter with no input pads is called a "source", and a filter with no
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output pads is called a "sink".
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@anchor{Filtergraph syntax}
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@section Filtergraph syntax
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A filtergraph has a textual representation, which is recognized by the
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@option{-filter}/@option{-vf}/@option{-af} and
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@option{-filter_complex} options in @command{ffmpeg} and
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@option{-vf}/@option{-af} in @command{ffplay}, and by the
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@code{avfilter_graph_parse_ptr()} function defined in
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@file{libavfilter/avfilter.h}.
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A filterchain consists of a sequence of connected filters, each one
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connected to the previous one in the sequence. A filterchain is
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represented by a list of ","-separated filter descriptions.
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A filtergraph consists of a sequence of filterchains. A sequence of
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filterchains is represented by a list of ";"-separated filterchain
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descriptions.
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A filter is represented by a string of the form:
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[@var{in_link_1}]...[@var{in_link_N}]@var{filter_name}@@@var{id}=@var{arguments}[@var{out_link_1}]...[@var{out_link_M}]
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@var{filter_name} is the name of the filter class of which the
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described filter is an instance of, and has to be the name of one of
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the filter classes registered in the program optionally followed by "@@@var{id}".
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The name of the filter class is optionally followed by a string
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"=@var{arguments}".
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@var{arguments} is a string which contains the parameters used to
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initialize the filter instance. It may have one of two forms:
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@itemize
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@item
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A ':'-separated list of @var{key=value} pairs.
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@item
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A ':'-separated list of @var{value}. In this case, the keys are assumed to be
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the option names in the order they are declared. E.g. the @code{fade} filter
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declares three options in this order -- @option{type}, @option{start_frame} and
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@option{nb_frames}. Then the parameter list @var{in:0:30} means that the value
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@var{in} is assigned to the option @option{type}, @var{0} to
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@option{start_frame} and @var{30} to @option{nb_frames}.
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@item
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A ':'-separated list of mixed direct @var{value} and long @var{key=value}
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pairs. The direct @var{value} must precede the @var{key=value} pairs, and
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follow the same constraints order of the previous point. The following
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@var{key=value} pairs can be set in any preferred order.
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@end itemize
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If the option value itself is a list of items (e.g. the @code{format} filter
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takes a list of pixel formats), the items in the list are usually separated by
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@samp{|}.
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The list of arguments can be quoted using the character @samp{'} as initial
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and ending mark, and the character @samp{\} for escaping the characters
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within the quoted text; otherwise the argument string is considered
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terminated when the next special character (belonging to the set
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@samp{[]=;,}) is encountered.
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The name and arguments of the filter are optionally preceded and
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followed by a list of link labels.
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A link label allows one to name a link and associate it to a filter output
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or input pad. The preceding labels @var{in_link_1}
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... @var{in_link_N}, are associated to the filter input pads,
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the following labels @var{out_link_1} ... @var{out_link_M}, are
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associated to the output pads.
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When two link labels with the same name are found in the
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filtergraph, a link between the corresponding input and output pad is
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created.
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If an output pad is not labelled, it is linked by default to the first
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unlabelled input pad of the next filter in the filterchain.
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For example in the filterchain
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@example
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nullsrc, split[L1], [L2]overlay, nullsink
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@end example
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the split filter instance has two output pads, and the overlay filter
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instance two input pads. The first output pad of split is labelled
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"L1", the first input pad of overlay is labelled "L2", and the second
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output pad of split is linked to the second input pad of overlay,
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which are both unlabelled.
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In a filter description, if the input label of the first filter is not
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specified, "in" is assumed; if the output label of the last filter is not
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specified, "out" is assumed.
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In a complete filterchain all the unlabelled filter input and output
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pads must be connected. A filtergraph is considered valid if all the
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filter input and output pads of all the filterchains are connected.
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Libavfilter will automatically insert @ref{scale} filters where format
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conversion is required. It is possible to specify swscale flags
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for those automatically inserted scalers by prepending
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@code{sws_flags=@var{flags};}
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to the filtergraph description.
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Here is a BNF description of the filtergraph syntax:
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@example
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@var{NAME} ::= sequence of alphanumeric characters and '_'
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@var{FILTER_NAME} ::= @var{NAME}["@@"@var{NAME}]
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@var{LINKLABEL} ::= "[" @var{NAME} "]"
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@var{LINKLABELS} ::= @var{LINKLABEL} [@var{LINKLABELS}]
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@var{FILTER_ARGUMENTS} ::= sequence of chars (possibly quoted)
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@var{FILTER} ::= [@var{LINKLABELS}] @var{FILTER_NAME} ["=" @var{FILTER_ARGUMENTS}] [@var{LINKLABELS}]
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@var{FILTERCHAIN} ::= @var{FILTER} [,@var{FILTERCHAIN}]
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@var{FILTERGRAPH} ::= [sws_flags=@var{flags};] @var{FILTERCHAIN} [;@var{FILTERGRAPH}]
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@end example
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@section Notes on filtergraph escaping
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Filtergraph description composition entails several levels of
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escaping. See @ref{quoting_and_escaping,,the "Quoting and escaping"
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section in the ffmpeg-utils(1) manual,ffmpeg-utils} for more
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information about the employed escaping procedure.
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A first level escaping affects the content of each filter option
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value, which may contain the special character @code{:} used to
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separate values, or one of the escaping characters @code{\'}.
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A second level escaping affects the whole filter description, which
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may contain the escaping characters @code{\'} or the special
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characters @code{[],;} used by the filtergraph description.
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Finally, when you specify a filtergraph on a shell commandline, you
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need to perform a third level escaping for the shell special
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characters contained within it.
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For example, consider the following string to be embedded in
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the @ref{drawtext} filter description @option{text} value:
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@example
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this is a 'string': may contain one, or more, special characters
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@end example
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This string contains the @code{'} special escaping character, and the
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@code{:} special character, so it needs to be escaped in this way:
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@example
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text=this is a \'string\'\: may contain one, or more, special characters
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@end example
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A second level of escaping is required when embedding the filter
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description in a filtergraph description, in order to escape all the
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filtergraph special characters. Thus the example above becomes:
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@example
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drawtext=text=this is a \\\'string\\\'\\: may contain one\, or more\, special characters
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@end example
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(note that in addition to the @code{\'} escaping special characters,
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also @code{,} needs to be escaped).
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Finally an additional level of escaping is needed when writing the
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filtergraph description in a shell command, which depends on the
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escaping rules of the adopted shell. For example, assuming that
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@code{\} is special and needs to be escaped with another @code{\}, the
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previous string will finally result in:
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@example
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-vf "drawtext=text=this is a \\\\\\'string\\\\\\'\\\\: may contain one\\, or more\\, special characters"
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@end example
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@chapter Timeline editing
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Some filters support a generic @option{enable} option. For the filters
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supporting timeline editing, this option can be set to an expression which is
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evaluated before sending a frame to the filter. If the evaluation is non-zero,
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the filter will be enabled, otherwise the frame will be sent unchanged to the
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next filter in the filtergraph.
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The expression accepts the following values:
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@table @samp
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@item t
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timestamp expressed in seconds, NAN if the input timestamp is unknown
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@item n
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sequential number of the input frame, starting from 0
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@item pos
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the position in the file of the input frame, NAN if unknown
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@item w
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@item h
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width and height of the input frame if video
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@end table
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Additionally, these filters support an @option{enable} command that can be used
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to re-define the expression.
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Like any other filtering option, the @option{enable} option follows the same
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rules.
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For example, to enable a blur filter (@ref{smartblur}) from 10 seconds to 3
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minutes, and a @ref{curves} filter starting at 3 seconds:
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@example
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smartblur = enable='between(t,10,3*60)',
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curves = enable='gte(t,3)' : preset=cross_process
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@end example
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See @code{ffmpeg -filters} to view which filters have timeline support.
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@c man end FILTERGRAPH DESCRIPTION
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@chapter Audio Filters
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@c man begin AUDIO FILTERS
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When you configure your FFmpeg build, you can disable any of the
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existing filters using @code{--disable-filters}.
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The configure output will show the audio filters included in your
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build.
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Below is a description of the currently available audio filters.
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@section acompressor
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A compressor is mainly used to reduce the dynamic range of a signal.
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Especially modern music is mostly compressed at a high ratio to
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improve the overall loudness. It's done to get the highest attention
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of a listener, "fatten" the sound and bring more "power" to the track.
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If a signal is compressed too much it may sound dull or "dead"
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afterwards or it may start to "pump" (which could be a powerful effect
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but can also destroy a track completely).
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The right compression is the key to reach a professional sound and is
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the high art of mixing and mastering. Because of its complex settings
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it may take a long time to get the right feeling for this kind of effect.
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Compression is done by detecting the volume above a chosen level
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@code{threshold} and dividing it by the factor set with @code{ratio}.
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So if you set the threshold to -12dB and your signal reaches -6dB a ratio
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of 2:1 will result in a signal at -9dB. Because an exact manipulation of
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the signal would cause distortion of the waveform the reduction can be
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levelled over the time. This is done by setting "Attack" and "Release".
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@code{attack} determines how long the signal has to rise above the threshold
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before any reduction will occur and @code{release} sets the time the signal
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has to fall below the threshold to reduce the reduction again. Shorter signals
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than the chosen attack time will be left untouched.
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The overall reduction of the signal can be made up afterwards with the
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@code{makeup} setting. So compressing the peaks of a signal about 6dB and
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raising the makeup to this level results in a signal twice as loud than the
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source. To gain a softer entry in the compression the @code{knee} flattens the
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hard edge at the threshold in the range of the chosen decibels.
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The filter accepts the following options:
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@table @option
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@item level_in
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Set input gain. Default is 1. Range is between 0.015625 and 64.
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@item threshold
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If a signal of stream rises above this level it will affect the gain
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reduction.
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By default it is 0.125. Range is between 0.00097563 and 1.
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@item ratio
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Set a ratio by which the signal is reduced. 1:2 means that if the level
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rose 4dB above the threshold, it will be only 2dB above after the reduction.
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Default is 2. Range is between 1 and 20.
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@item attack
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Amount of milliseconds the signal has to rise above the threshold before gain
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reduction starts. Default is 20. Range is between 0.01 and 2000.
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@item release
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Amount of milliseconds the signal has to fall below the threshold before
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reduction is decreased again. Default is 250. Range is between 0.01 and 9000.
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@item makeup
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Set the amount by how much signal will be amplified after processing.
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Default is 1. Range is from 1 to 64.
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@item knee
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Curve the sharp knee around the threshold to enter gain reduction more softly.
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Default is 2.82843. Range is between 1 and 8.
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@item link
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Choose if the @code{average} level between all channels of input stream
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or the louder(@code{maximum}) channel of input stream affects the
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reduction. Default is @code{average}.
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||
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@item detection
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Should the exact signal be taken in case of @code{peak} or an RMS one in case
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of @code{rms}. Default is @code{rms} which is mostly smoother.
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@item mix
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How much to use compressed signal in output. Default is 1.
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Range is between 0 and 1.
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@end table
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@section acopy
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Copy the input audio source unchanged to the output. This is mainly useful for
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testing purposes.
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||
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||
@section acrossfade
|
||
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Apply cross fade from one input audio stream to another input audio stream.
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||
The cross fade is applied for specified duration near the end of first stream.
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The filter accepts the following options:
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||
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@table @option
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@item nb_samples, ns
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Specify the number of samples for which the cross fade effect has to last.
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At the end of the cross fade effect the first input audio will be completely
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silent. Default is 44100.
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||
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||
@item duration, d
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Specify the duration of the cross fade effect. See
|
||
@ref{time duration syntax,,the Time duration section in the ffmpeg-utils(1) manual,ffmpeg-utils}
|
||
for the accepted syntax.
|
||
By default the duration is determined by @var{nb_samples}.
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||
If set this option is used instead of @var{nb_samples}.
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||
|
||
@item overlap, o
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Should first stream end overlap with second stream start. Default is enabled.
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||
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||
@item curve1
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Set curve for cross fade transition for first stream.
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||
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||
@item curve2
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||
Set curve for cross fade transition for second stream.
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||
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||
For description of available curve types see @ref{afade} filter description.
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
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||
Cross fade from one input to another:
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||
@example
|
||
ffmpeg -i first.flac -i second.flac -filter_complex acrossfade=d=10:c1=exp:c2=exp output.flac
|
||
@end example
|
||
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||
@item
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||
Cross fade from one input to another but without overlapping:
|
||
@example
|
||
ffmpeg -i first.flac -i second.flac -filter_complex acrossfade=d=10:o=0:c1=exp:c2=exp output.flac
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||
@end example
|
||
@end itemize
|
||
|
||
@section acrusher
|
||
|
||
Reduce audio bit resolution.
|
||
|
||
This filter is bit crusher with enhanced functionality. A bit crusher
|
||
is used to audibly reduce number of bits an audio signal is sampled
|
||
with. This doesn't change the bit depth at all, it just produces the
|
||
effect. Material reduced in bit depth sounds more harsh and "digital".
|
||
This filter is able to even round to continuous values instead of discrete
|
||
bit depths.
|
||
Additionally it has a D/C offset which results in different crushing of
|
||
the lower and the upper half of the signal.
|
||
An Anti-Aliasing setting is able to produce "softer" crushing sounds.
|
||
|
||
Another feature of this filter is the logarithmic mode.
|
||
This setting switches from linear distances between bits to logarithmic ones.
|
||
The result is a much more "natural" sounding crusher which doesn't gate low
|
||
signals for example. The human ear has a logarithmic perception, too
|
||
so this kind of crushing is much more pleasant.
|
||
Logarithmic crushing is also able to get anti-aliased.
|
||
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||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item level_in
|
||
Set level in.
|
||
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||
@item level_out
|
||
Set level out.
|
||
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||
@item bits
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||
Set bit reduction.
|
||
|
||
@item mix
|
||
Set mixing amount.
|
||
|
||
@item mode
|
||
Can be linear: @code{lin} or logarithmic: @code{log}.
|
||
|
||
@item dc
|
||
Set DC.
|
||
|
||
@item aa
|
||
Set anti-aliasing.
|
||
|
||
@item samples
|
||
Set sample reduction.
|
||
|
||
@item lfo
|
||
Enable LFO. By default disabled.
|
||
|
||
@item lforange
|
||
Set LFO range.
|
||
|
||
@item lforate
|
||
Set LFO rate.
|
||
@end table
|
||
|
||
@section adelay
|
||
|
||
Delay one or more audio channels.
|
||
|
||
Samples in delayed channel are filled with silence.
|
||
|
||
The filter accepts the following option:
|
||
|
||
@table @option
|
||
@item delays
|
||
Set list of delays in milliseconds for each channel separated by '|'.
|
||
At least one delay greater than 0 should be provided.
|
||
Unused delays will be silently ignored. If number of given delays is
|
||
smaller than number of channels all remaining channels will not be delayed.
|
||
If you want to delay exact number of samples, append 'S' to number.
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Delay first channel by 1.5 seconds, the third channel by 0.5 seconds and leave
|
||
the second channel (and any other channels that may be present) unchanged.
|
||
@example
|
||
adelay=1500|0|500
|
||
@end example
|
||
|
||
@item
|
||
Delay second channel by 500 samples, the third channel by 700 samples and leave
|
||
the first channel (and any other channels that may be present) unchanged.
|
||
@example
|
||
adelay=0|500S|700S
|
||
@end example
|
||
@end itemize
|
||
|
||
@section aecho
|
||
|
||
Apply echoing to the input audio.
|
||
|
||
Echoes are reflected sound and can occur naturally amongst mountains
|
||
(and sometimes large buildings) when talking or shouting; digital echo
|
||
effects emulate this behaviour and are often used to help fill out the
|
||
sound of a single instrument or vocal. The time difference between the
|
||
original signal and the reflection is the @code{delay}, and the
|
||
loudness of the reflected signal is the @code{decay}.
|
||
Multiple echoes can have different delays and decays.
|
||
|
||
A description of the accepted parameters follows.
|
||
|
||
@table @option
|
||
@item in_gain
|
||
Set input gain of reflected signal. Default is @code{0.6}.
|
||
|
||
@item out_gain
|
||
Set output gain of reflected signal. Default is @code{0.3}.
|
||
|
||
@item delays
|
||
Set list of time intervals in milliseconds between original signal and reflections
|
||
separated by '|'. Allowed range for each @code{delay} is @code{(0 - 90000.0]}.
|
||
Default is @code{1000}.
|
||
|
||
@item decays
|
||
Set list of loudnesses of reflected signals separated by '|'.
|
||
Allowed range for each @code{decay} is @code{(0 - 1.0]}.
|
||
Default is @code{0.5}.
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Make it sound as if there are twice as many instruments as are actually playing:
|
||
@example
|
||
aecho=0.8:0.88:60:0.4
|
||
@end example
|
||
|
||
@item
|
||
If delay is very short, then it sound like a (metallic) robot playing music:
|
||
@example
|
||
aecho=0.8:0.88:6:0.4
|
||
@end example
|
||
|
||
@item
|
||
A longer delay will sound like an open air concert in the mountains:
|
||
@example
|
||
aecho=0.8:0.9:1000:0.3
|
||
@end example
|
||
|
||
@item
|
||
Same as above but with one more mountain:
|
||
@example
|
||
aecho=0.8:0.9:1000|1800:0.3|0.25
|
||
@end example
|
||
@end itemize
|
||
|
||
@section aemphasis
|
||
Audio emphasis filter creates or restores material directly taken from LPs or
|
||
emphased CDs with different filter curves. E.g. to store music on vinyl the
|
||
signal has to be altered by a filter first to even out the disadvantages of
|
||
this recording medium.
|
||
Once the material is played back the inverse filter has to be applied to
|
||
restore the distortion of the frequency response.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item level_in
|
||
Set input gain.
|
||
|
||
@item level_out
|
||
Set output gain.
|
||
|
||
@item mode
|
||
Set filter mode. For restoring material use @code{reproduction} mode, otherwise
|
||
use @code{production} mode. Default is @code{reproduction} mode.
|
||
|
||
@item type
|
||
Set filter type. Selects medium. Can be one of the following:
|
||
|
||
@table @option
|
||
@item col
|
||
select Columbia.
|
||
@item emi
|
||
select EMI.
|
||
@item bsi
|
||
select BSI (78RPM).
|
||
@item riaa
|
||
select RIAA.
|
||
@item cd
|
||
select Compact Disc (CD).
|
||
@item 50fm
|
||
select 50µs (FM).
|
||
@item 75fm
|
||
select 75µs (FM).
|
||
@item 50kf
|
||
select 50µs (FM-KF).
|
||
@item 75kf
|
||
select 75µs (FM-KF).
|
||
@end table
|
||
@end table
|
||
|
||
@section aeval
|
||
|
||
Modify an audio signal according to the specified expressions.
|
||
|
||
This filter accepts one or more expressions (one for each channel),
|
||
which are evaluated and used to modify a corresponding audio signal.
|
||
|
||
It accepts the following parameters:
|
||
|
||
@table @option
|
||
@item exprs
|
||
Set the '|'-separated expressions list for each separate channel. If
|
||
the number of input channels is greater than the number of
|
||
expressions, the last specified expression is used for the remaining
|
||
output channels.
|
||
|
||
@item channel_layout, c
|
||
Set output channel layout. If not specified, the channel layout is
|
||
specified by the number of expressions. If set to @samp{same}, it will
|
||
use by default the same input channel layout.
|
||
@end table
|
||
|
||
Each expression in @var{exprs} can contain the following constants and functions:
|
||
|
||
@table @option
|
||
@item ch
|
||
channel number of the current expression
|
||
|
||
@item n
|
||
number of the evaluated sample, starting from 0
|
||
|
||
@item s
|
||
sample rate
|
||
|
||
@item t
|
||
time of the evaluated sample expressed in seconds
|
||
|
||
@item nb_in_channels
|
||
@item nb_out_channels
|
||
input and output number of channels
|
||
|
||
@item val(CH)
|
||
the value of input channel with number @var{CH}
|
||
@end table
|
||
|
||
Note: this filter is slow. For faster processing you should use a
|
||
dedicated filter.
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Half volume:
|
||
@example
|
||
aeval=val(ch)/2:c=same
|
||
@end example
|
||
|
||
@item
|
||
Invert phase of the second channel:
|
||
@example
|
||
aeval=val(0)|-val(1)
|
||
@end example
|
||
@end itemize
|
||
|
||
@anchor{afade}
|
||
@section afade
|
||
|
||
Apply fade-in/out effect to input audio.
|
||
|
||
A description of the accepted parameters follows.
|
||
|
||
@table @option
|
||
@item type, t
|
||
Specify the effect type, can be either @code{in} for fade-in, or
|
||
@code{out} for a fade-out effect. Default is @code{in}.
|
||
|
||
@item start_sample, ss
|
||
Specify the number of the start sample for starting to apply the fade
|
||
effect. Default is 0.
|
||
|
||
@item nb_samples, ns
|
||
Specify the number of samples for which the fade effect has to last. At
|
||
the end of the fade-in effect the output audio will have the same
|
||
volume as the input audio, at the end of the fade-out transition
|
||
the output audio will be silence. Default is 44100.
|
||
|
||
@item start_time, st
|
||
Specify the start time of the fade effect. Default is 0.
|
||
The value must be specified as a time duration; see
|
||
@ref{time duration syntax,,the Time duration section in the ffmpeg-utils(1) manual,ffmpeg-utils}
|
||
for the accepted syntax.
|
||
If set this option is used instead of @var{start_sample}.
|
||
|
||
@item duration, d
|
||
Specify the duration of the fade effect. See
|
||
@ref{time duration syntax,,the Time duration section in the ffmpeg-utils(1) manual,ffmpeg-utils}
|
||
for the accepted syntax.
|
||
At the end of the fade-in effect the output audio will have the same
|
||
volume as the input audio, at the end of the fade-out transition
|
||
the output audio will be silence.
|
||
By default the duration is determined by @var{nb_samples}.
|
||
If set this option is used instead of @var{nb_samples}.
|
||
|
||
@item curve
|
||
Set curve for fade transition.
|
||
|
||
It accepts the following values:
|
||
@table @option
|
||
@item tri
|
||
select triangular, linear slope (default)
|
||
@item qsin
|
||
select quarter of sine wave
|
||
@item hsin
|
||
select half of sine wave
|
||
@item esin
|
||
select exponential sine wave
|
||
@item log
|
||
select logarithmic
|
||
@item ipar
|
||
select inverted parabola
|
||
@item qua
|
||
select quadratic
|
||
@item cub
|
||
select cubic
|
||
@item squ
|
||
select square root
|
||
@item cbr
|
||
select cubic root
|
||
@item par
|
||
select parabola
|
||
@item exp
|
||
select exponential
|
||
@item iqsin
|
||
select inverted quarter of sine wave
|
||
@item ihsin
|
||
select inverted half of sine wave
|
||
@item dese
|
||
select double-exponential seat
|
||
@item desi
|
||
select double-exponential sigmoid
|
||
@end table
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Fade in first 15 seconds of audio:
|
||
@example
|
||
afade=t=in:ss=0:d=15
|
||
@end example
|
||
|
||
@item
|
||
Fade out last 25 seconds of a 900 seconds audio:
|
||
@example
|
||
afade=t=out:st=875:d=25
|
||
@end example
|
||
@end itemize
|
||
|
||
@section afftfilt
|
||
Apply arbitrary expressions to samples in frequency domain.
|
||
|
||
@table @option
|
||
@item real
|
||
Set frequency domain real expression for each separate channel separated
|
||
by '|'. Default is "1".
|
||
If the number of input channels is greater than the number of
|
||
expressions, the last specified expression is used for the remaining
|
||
output channels.
|
||
|
||
@item imag
|
||
Set frequency domain imaginary expression for each separate channel
|
||
separated by '|'. If not set, @var{real} option is used.
|
||
|
||
Each expression in @var{real} and @var{imag} can contain the following
|
||
constants:
|
||
|
||
@table @option
|
||
@item sr
|
||
sample rate
|
||
|
||
@item b
|
||
current frequency bin number
|
||
|
||
@item nb
|
||
number of available bins
|
||
|
||
@item ch
|
||
channel number of the current expression
|
||
|
||
@item chs
|
||
number of channels
|
||
|
||
@item pts
|
||
current frame pts
|
||
@end table
|
||
|
||
@item win_size
|
||
Set window size.
|
||
|
||
It accepts the following values:
|
||
@table @samp
|
||
@item w16
|
||
@item w32
|
||
@item w64
|
||
@item w128
|
||
@item w256
|
||
@item w512
|
||
@item w1024
|
||
@item w2048
|
||
@item w4096
|
||
@item w8192
|
||
@item w16384
|
||
@item w32768
|
||
@item w65536
|
||
@end table
|
||
Default is @code{w4096}
|
||
|
||
@item win_func
|
||
Set window function. Default is @code{hann}.
|
||
|
||
@item overlap
|
||
Set window overlap. If set to 1, the recommended overlap for selected
|
||
window function will be picked. Default is @code{0.75}.
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Leave almost only low frequencies in audio:
|
||
@example
|
||
afftfilt="1-clip((b/nb)*b,0,1)"
|
||
@end example
|
||
@end itemize
|
||
|
||
@section afir
|
||
|
||
Apply an arbitrary Frequency Impulse Response filter.
|
||
|
||
This filter is designed for applying long FIR filters,
|
||
up to 30 seconds long.
|
||
|
||
It can be used as component for digital crossover filters,
|
||
room equalization, cross talk cancellation, wavefield synthesis,
|
||
auralization, ambiophonics and ambisonics.
|
||
|
||
This filter uses second stream as FIR coefficients.
|
||
If second stream holds single channel, it will be used
|
||
for all input channels in first stream, otherwise
|
||
number of channels in second stream must be same as
|
||
number of channels in first stream.
|
||
|
||
It accepts the following parameters:
|
||
|
||
@table @option
|
||
@item dry
|
||
Set dry gain. This sets input gain.
|
||
|
||
@item wet
|
||
Set wet gain. This sets final output gain.
|
||
|
||
@item length
|
||
Set Impulse Response filter length. Default is 1, which means whole IR is processed.
|
||
|
||
@item again
|
||
Enable applying gain measured from power of IR.
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Apply reverb to stream using mono IR file as second input, complete command using ffmpeg:
|
||
@example
|
||
ffmpeg -i input.wav -i middle_tunnel_1way_mono.wav -lavfi afir output.wav
|
||
@end example
|
||
@end itemize
|
||
|
||
@anchor{aformat}
|
||
@section aformat
|
||
|
||
Set output format constraints for the input audio. The framework will
|
||
negotiate the most appropriate format to minimize conversions.
|
||
|
||
It accepts the following parameters:
|
||
@table @option
|
||
|
||
@item sample_fmts
|
||
A '|'-separated list of requested sample formats.
|
||
|
||
@item sample_rates
|
||
A '|'-separated list of requested sample rates.
|
||
|
||
@item channel_layouts
|
||
A '|'-separated list of requested channel layouts.
|
||
|
||
See @ref{channel layout syntax,,the Channel Layout section in the ffmpeg-utils(1) manual,ffmpeg-utils}
|
||
for the required syntax.
|
||
@end table
|
||
|
||
If a parameter is omitted, all values are allowed.
|
||
|
||
Force the output to either unsigned 8-bit or signed 16-bit stereo
|
||
@example
|
||
aformat=sample_fmts=u8|s16:channel_layouts=stereo
|
||
@end example
|
||
|
||
@section agate
|
||
|
||
A gate is mainly used to reduce lower parts of a signal. This kind of signal
|
||
processing reduces disturbing noise between useful signals.
|
||
|
||
Gating is done by detecting the volume below a chosen level @var{threshold}
|
||
and dividing it by the factor set with @var{ratio}. The bottom of the noise
|
||
floor is set via @var{range}. Because an exact manipulation of the signal
|
||
would cause distortion of the waveform the reduction can be levelled over
|
||
time. This is done by setting @var{attack} and @var{release}.
|
||
|
||
@var{attack} determines how long the signal has to fall below the threshold
|
||
before any reduction will occur and @var{release} sets the time the signal
|
||
has to rise above the threshold to reduce the reduction again.
|
||
Shorter signals than the chosen attack time will be left untouched.
|
||
|
||
@table @option
|
||
@item level_in
|
||
Set input level before filtering.
|
||
Default is 1. Allowed range is from 0.015625 to 64.
|
||
|
||
@item range
|
||
Set the level of gain reduction when the signal is below the threshold.
|
||
Default is 0.06125. Allowed range is from 0 to 1.
|
||
|
||
@item threshold
|
||
If a signal rises above this level the gain reduction is released.
|
||
Default is 0.125. Allowed range is from 0 to 1.
|
||
|
||
@item ratio
|
||
Set a ratio by which the signal is reduced.
|
||
Default is 2. Allowed range is from 1 to 9000.
|
||
|
||
@item attack
|
||
Amount of milliseconds the signal has to rise above the threshold before gain
|
||
reduction stops.
|
||
Default is 20 milliseconds. Allowed range is from 0.01 to 9000.
|
||
|
||
@item release
|
||
Amount of milliseconds the signal has to fall below the threshold before the
|
||
reduction is increased again. Default is 250 milliseconds.
|
||
Allowed range is from 0.01 to 9000.
|
||
|
||
@item makeup
|
||
Set amount of amplification of signal after processing.
|
||
Default is 1. Allowed range is from 1 to 64.
|
||
|
||
@item knee
|
||
Curve the sharp knee around the threshold to enter gain reduction more softly.
|
||
Default is 2.828427125. Allowed range is from 1 to 8.
|
||
|
||
@item detection
|
||
Choose if exact signal should be taken for detection or an RMS like one.
|
||
Default is @code{rms}. Can be @code{peak} or @code{rms}.
|
||
|
||
@item link
|
||
Choose if the average level between all channels or the louder channel affects
|
||
the reduction.
|
||
Default is @code{average}. Can be @code{average} or @code{maximum}.
|
||
@end table
|
||
|
||
@section alimiter
|
||
|
||
The limiter prevents an input signal from rising over a desired threshold.
|
||
This limiter uses lookahead technology to prevent your signal from distorting.
|
||
It means that there is a small delay after the signal is processed. Keep in mind
|
||
that the delay it produces is the attack time you set.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item level_in
|
||
Set input gain. Default is 1.
|
||
|
||
@item level_out
|
||
Set output gain. Default is 1.
|
||
|
||
@item limit
|
||
Don't let signals above this level pass the limiter. Default is 1.
|
||
|
||
@item attack
|
||
The limiter will reach its attenuation level in this amount of time in
|
||
milliseconds. Default is 5 milliseconds.
|
||
|
||
@item release
|
||
Come back from limiting to attenuation 1.0 in this amount of milliseconds.
|
||
Default is 50 milliseconds.
|
||
|
||
@item asc
|
||
When gain reduction is always needed ASC takes care of releasing to an
|
||
average reduction level rather than reaching a reduction of 0 in the release
|
||
time.
|
||
|
||
@item asc_level
|
||
Select how much the release time is affected by ASC, 0 means nearly no changes
|
||
in release time while 1 produces higher release times.
|
||
|
||
@item level
|
||
Auto level output signal. Default is enabled.
|
||
This normalizes audio back to 0dB if enabled.
|
||
@end table
|
||
|
||
Depending on picked setting it is recommended to upsample input 2x or 4x times
|
||
with @ref{aresample} before applying this filter.
|
||
|
||
@section allpass
|
||
|
||
Apply a two-pole all-pass filter with central frequency (in Hz)
|
||
@var{frequency}, and filter-width @var{width}.
|
||
An all-pass filter changes the audio's frequency to phase relationship
|
||
without changing its frequency to amplitude relationship.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item frequency, f
|
||
Set frequency in Hz.
|
||
|
||
@item width_type, t
|
||
Set method to specify band-width of filter.
|
||
@table @option
|
||
@item h
|
||
Hz
|
||
@item q
|
||
Q-Factor
|
||
@item o
|
||
octave
|
||
@item s
|
||
slope
|
||
@end table
|
||
|
||
@item width, w
|
||
Specify the band-width of a filter in width_type units.
|
||
|
||
@item channels, c
|
||
Specify which channels to filter, by default all available are filtered.
|
||
@end table
|
||
|
||
@section aloop
|
||
|
||
Loop audio samples.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item loop
|
||
Set the number of loops.
|
||
|
||
@item size
|
||
Set maximal number of samples.
|
||
|
||
@item start
|
||
Set first sample of loop.
|
||
@end table
|
||
|
||
@anchor{amerge}
|
||
@section amerge
|
||
|
||
Merge two or more audio streams into a single multi-channel stream.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
|
||
@item inputs
|
||
Set the number of inputs. Default is 2.
|
||
|
||
@end table
|
||
|
||
If the channel layouts of the inputs are disjoint, and therefore compatible,
|
||
the channel layout of the output will be set accordingly and the channels
|
||
will be reordered as necessary. If the channel layouts of the inputs are not
|
||
disjoint, the output will have all the channels of the first input then all
|
||
the channels of the second input, in that order, and the channel layout of
|
||
the output will be the default value corresponding to the total number of
|
||
channels.
|
||
|
||
For example, if the first input is in 2.1 (FL+FR+LF) and the second input
|
||
is FC+BL+BR, then the output will be in 5.1, with the channels in the
|
||
following order: a1, a2, b1, a3, b2, b3 (a1 is the first channel of the
|
||
first input, b1 is the first channel of the second input).
|
||
|
||
On the other hand, if both input are in stereo, the output channels will be
|
||
in the default order: a1, a2, b1, b2, and the channel layout will be
|
||
arbitrarily set to 4.0, which may or may not be the expected value.
|
||
|
||
All inputs must have the same sample rate, and format.
|
||
|
||
If inputs do not have the same duration, the output will stop with the
|
||
shortest.
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Merge two mono files into a stereo stream:
|
||
@example
|
||
amovie=left.wav [l] ; amovie=right.mp3 [r] ; [l] [r] amerge
|
||
@end example
|
||
|
||
@item
|
||
Multiple merges assuming 1 video stream and 6 audio streams in @file{input.mkv}:
|
||
@example
|
||
ffmpeg -i input.mkv -filter_complex "[0:1][0:2][0:3][0:4][0:5][0:6] amerge=inputs=6" -c:a pcm_s16le output.mkv
|
||
@end example
|
||
@end itemize
|
||
|
||
@section amix
|
||
|
||
Mixes multiple audio inputs into a single output.
|
||
|
||
Note that this filter only supports float samples (the @var{amerge}
|
||
and @var{pan} audio filters support many formats). If the @var{amix}
|
||
input has integer samples then @ref{aresample} will be automatically
|
||
inserted to perform the conversion to float samples.
|
||
|
||
For example
|
||
@example
|
||
ffmpeg -i INPUT1 -i INPUT2 -i INPUT3 -filter_complex amix=inputs=3:duration=first:dropout_transition=3 OUTPUT
|
||
@end example
|
||
will mix 3 input audio streams to a single output with the same duration as the
|
||
first input and a dropout transition time of 3 seconds.
|
||
|
||
It accepts the following parameters:
|
||
@table @option
|
||
|
||
@item inputs
|
||
The number of inputs. If unspecified, it defaults to 2.
|
||
|
||
@item duration
|
||
How to determine the end-of-stream.
|
||
@table @option
|
||
|
||
@item longest
|
||
The duration of the longest input. (default)
|
||
|
||
@item shortest
|
||
The duration of the shortest input.
|
||
|
||
@item first
|
||
The duration of the first input.
|
||
|
||
@end table
|
||
|
||
@item dropout_transition
|
||
The transition time, in seconds, for volume renormalization when an input
|
||
stream ends. The default value is 2 seconds.
|
||
|
||
@end table
|
||
|
||
@section anequalizer
|
||
|
||
High-order parametric multiband equalizer for each channel.
|
||
|
||
It accepts the following parameters:
|
||
@table @option
|
||
@item params
|
||
|
||
This option string is in format:
|
||
"c@var{chn} f=@var{cf} w=@var{w} g=@var{g} t=@var{f} | ..."
|
||
Each equalizer band is separated by '|'.
|
||
|
||
@table @option
|
||
@item chn
|
||
Set channel number to which equalization will be applied.
|
||
If input doesn't have that channel the entry is ignored.
|
||
|
||
@item f
|
||
Set central frequency for band.
|
||
If input doesn't have that frequency the entry is ignored.
|
||
|
||
@item w
|
||
Set band width in hertz.
|
||
|
||
@item g
|
||
Set band gain in dB.
|
||
|
||
@item t
|
||
Set filter type for band, optional, can be:
|
||
|
||
@table @samp
|
||
@item 0
|
||
Butterworth, this is default.
|
||
|
||
@item 1
|
||
Chebyshev type 1.
|
||
|
||
@item 2
|
||
Chebyshev type 2.
|
||
@end table
|
||
@end table
|
||
|
||
@item curves
|
||
With this option activated frequency response of anequalizer is displayed
|
||
in video stream.
|
||
|
||
@item size
|
||
Set video stream size. Only useful if curves option is activated.
|
||
|
||
@item mgain
|
||
Set max gain that will be displayed. Only useful if curves option is activated.
|
||
Setting this to a reasonable value makes it possible to display gain which is derived from
|
||
neighbour bands which are too close to each other and thus produce higher gain
|
||
when both are activated.
|
||
|
||
@item fscale
|
||
Set frequency scale used to draw frequency response in video output.
|
||
Can be linear or logarithmic. Default is logarithmic.
|
||
|
||
@item colors
|
||
Set color for each channel curve which is going to be displayed in video stream.
|
||
This is list of color names separated by space or by '|'.
|
||
Unrecognised or missing colors will be replaced by white color.
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Lower gain by 10 of central frequency 200Hz and width 100 Hz
|
||
for first 2 channels using Chebyshev type 1 filter:
|
||
@example
|
||
anequalizer=c0 f=200 w=100 g=-10 t=1|c1 f=200 w=100 g=-10 t=1
|
||
@end example
|
||
@end itemize
|
||
|
||
@subsection Commands
|
||
|
||
This filter supports the following commands:
|
||
@table @option
|
||
@item change
|
||
Alter existing filter parameters.
|
||
Syntax for the commands is : "@var{fN}|f=@var{freq}|w=@var{width}|g=@var{gain}"
|
||
|
||
@var{fN} is existing filter number, starting from 0, if no such filter is available
|
||
error is returned.
|
||
@var{freq} set new frequency parameter.
|
||
@var{width} set new width parameter in herz.
|
||
@var{gain} set new gain parameter in dB.
|
||
|
||
Full filter invocation with asendcmd may look like this:
|
||
asendcmd=c='4.0 anequalizer change 0|f=200|w=50|g=1',anequalizer=...
|
||
@end table
|
||
|
||
@section anull
|
||
|
||
Pass the audio source unchanged to the output.
|
||
|
||
@section apad
|
||
|
||
Pad the end of an audio stream with silence.
|
||
|
||
This can be used together with @command{ffmpeg} @option{-shortest} to
|
||
extend audio streams to the same length as the video stream.
|
||
|
||
A description of the accepted options follows.
|
||
|
||
@table @option
|
||
@item packet_size
|
||
Set silence packet size. Default value is 4096.
|
||
|
||
@item pad_len
|
||
Set the number of samples of silence to add to the end. After the
|
||
value is reached, the stream is terminated. This option is mutually
|
||
exclusive with @option{whole_len}.
|
||
|
||
@item whole_len
|
||
Set the minimum total number of samples in the output audio stream. If
|
||
the value is longer than the input audio length, silence is added to
|
||
the end, until the value is reached. This option is mutually exclusive
|
||
with @option{pad_len}.
|
||
@end table
|
||
|
||
If neither the @option{pad_len} nor the @option{whole_len} option is
|
||
set, the filter will add silence to the end of the input stream
|
||
indefinitely.
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Add 1024 samples of silence to the end of the input:
|
||
@example
|
||
apad=pad_len=1024
|
||
@end example
|
||
|
||
@item
|
||
Make sure the audio output will contain at least 10000 samples, pad
|
||
the input with silence if required:
|
||
@example
|
||
apad=whole_len=10000
|
||
@end example
|
||
|
||
@item
|
||
Use @command{ffmpeg} to pad the audio input with silence, so that the
|
||
video stream will always result the shortest and will be converted
|
||
until the end in the output file when using the @option{shortest}
|
||
option:
|
||
@example
|
||
ffmpeg -i VIDEO -i AUDIO -filter_complex "[1:0]apad" -shortest OUTPUT
|
||
@end example
|
||
@end itemize
|
||
|
||
@section aphaser
|
||
Add a phasing effect to the input audio.
|
||
|
||
A phaser filter creates series of peaks and troughs in the frequency spectrum.
|
||
The position of the peaks and troughs are modulated so that they vary over time, creating a sweeping effect.
|
||
|
||
A description of the accepted parameters follows.
|
||
|
||
@table @option
|
||
@item in_gain
|
||
Set input gain. Default is 0.4.
|
||
|
||
@item out_gain
|
||
Set output gain. Default is 0.74
|
||
|
||
@item delay
|
||
Set delay in milliseconds. Default is 3.0.
|
||
|
||
@item decay
|
||
Set decay. Default is 0.4.
|
||
|
||
@item speed
|
||
Set modulation speed in Hz. Default is 0.5.
|
||
|
||
@item type
|
||
Set modulation type. Default is triangular.
|
||
|
||
It accepts the following values:
|
||
@table @samp
|
||
@item triangular, t
|
||
@item sinusoidal, s
|
||
@end table
|
||
@end table
|
||
|
||
@section apulsator
|
||
|
||
Audio pulsator is something between an autopanner and a tremolo.
|
||
But it can produce funny stereo effects as well. Pulsator changes the volume
|
||
of the left and right channel based on a LFO (low frequency oscillator) with
|
||
different waveforms and shifted phases.
|
||
This filter have the ability to define an offset between left and right
|
||
channel. An offset of 0 means that both LFO shapes match each other.
|
||
The left and right channel are altered equally - a conventional tremolo.
|
||
An offset of 50% means that the shape of the right channel is exactly shifted
|
||
in phase (or moved backwards about half of the frequency) - pulsator acts as
|
||
an autopanner. At 1 both curves match again. Every setting in between moves the
|
||
phase shift gapless between all stages and produces some "bypassing" sounds with
|
||
sine and triangle waveforms. The more you set the offset near 1 (starting from
|
||
the 0.5) the faster the signal passes from the left to the right speaker.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item level_in
|
||
Set input gain. By default it is 1. Range is [0.015625 - 64].
|
||
|
||
@item level_out
|
||
Set output gain. By default it is 1. Range is [0.015625 - 64].
|
||
|
||
@item mode
|
||
Set waveform shape the LFO will use. Can be one of: sine, triangle, square,
|
||
sawup or sawdown. Default is sine.
|
||
|
||
@item amount
|
||
Set modulation. Define how much of original signal is affected by the LFO.
|
||
|
||
@item offset_l
|
||
Set left channel offset. Default is 0. Allowed range is [0 - 1].
|
||
|
||
@item offset_r
|
||
Set right channel offset. Default is 0.5. Allowed range is [0 - 1].
|
||
|
||
@item width
|
||
Set pulse width. Default is 1. Allowed range is [0 - 2].
|
||
|
||
@item timing
|
||
Set possible timing mode. Can be one of: bpm, ms or hz. Default is hz.
|
||
|
||
@item bpm
|
||
Set bpm. Default is 120. Allowed range is [30 - 300]. Only used if timing
|
||
is set to bpm.
|
||
|
||
@item ms
|
||
Set ms. Default is 500. Allowed range is [10 - 2000]. Only used if timing
|
||
is set to ms.
|
||
|
||
@item hz
|
||
Set frequency in Hz. Default is 2. Allowed range is [0.01 - 100]. Only used
|
||
if timing is set to hz.
|
||
@end table
|
||
|
||
@anchor{aresample}
|
||
@section aresample
|
||
|
||
Resample the input audio to the specified parameters, using the
|
||
libswresample library. If none are specified then the filter will
|
||
automatically convert between its input and output.
|
||
|
||
This filter is also able to stretch/squeeze the audio data to make it match
|
||
the timestamps or to inject silence / cut out audio to make it match the
|
||
timestamps, do a combination of both or do neither.
|
||
|
||
The filter accepts the syntax
|
||
[@var{sample_rate}:]@var{resampler_options}, where @var{sample_rate}
|
||
expresses a sample rate and @var{resampler_options} is a list of
|
||
@var{key}=@var{value} pairs, separated by ":". See the
|
||
@ref{Resampler Options,,the "Resampler Options" section in the
|
||
ffmpeg-resampler(1) manual,ffmpeg-resampler}
|
||
for the complete list of supported options.
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Resample the input audio to 44100Hz:
|
||
@example
|
||
aresample=44100
|
||
@end example
|
||
|
||
@item
|
||
Stretch/squeeze samples to the given timestamps, with a maximum of 1000
|
||
samples per second compensation:
|
||
@example
|
||
aresample=async=1000
|
||
@end example
|
||
@end itemize
|
||
|
||
@section areverse
|
||
|
||
Reverse an audio clip.
|
||
|
||
Warning: This filter requires memory to buffer the entire clip, so trimming
|
||
is suggested.
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Take the first 5 seconds of a clip, and reverse it.
|
||
@example
|
||
atrim=end=5,areverse
|
||
@end example
|
||
@end itemize
|
||
|
||
@section asetnsamples
|
||
|
||
Set the number of samples per each output audio frame.
|
||
|
||
The last output packet may contain a different number of samples, as
|
||
the filter will flush all the remaining samples when the input audio
|
||
signals its end.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
|
||
@item nb_out_samples, n
|
||
Set the number of frames per each output audio frame. The number is
|
||
intended as the number of samples @emph{per each channel}.
|
||
Default value is 1024.
|
||
|
||
@item pad, p
|
||
If set to 1, the filter will pad the last audio frame with zeroes, so
|
||
that the last frame will contain the same number of samples as the
|
||
previous ones. Default value is 1.
|
||
@end table
|
||
|
||
For example, to set the number of per-frame samples to 1234 and
|
||
disable padding for the last frame, use:
|
||
@example
|
||
asetnsamples=n=1234:p=0
|
||
@end example
|
||
|
||
@section asetrate
|
||
|
||
Set the sample rate without altering the PCM data.
|
||
This will result in a change of speed and pitch.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item sample_rate, r
|
||
Set the output sample rate. Default is 44100 Hz.
|
||
@end table
|
||
|
||
@section ashowinfo
|
||
|
||
Show a line containing various information for each input audio frame.
|
||
The input audio is not modified.
|
||
|
||
The shown line contains a sequence of key/value pairs of the form
|
||
@var{key}:@var{value}.
|
||
|
||
The following values are shown in the output:
|
||
|
||
@table @option
|
||
@item n
|
||
The (sequential) number of the input frame, starting from 0.
|
||
|
||
@item pts
|
||
The presentation timestamp of the input frame, in time base units; the time base
|
||
depends on the filter input pad, and is usually 1/@var{sample_rate}.
|
||
|
||
@item pts_time
|
||
The presentation timestamp of the input frame in seconds.
|
||
|
||
@item pos
|
||
position of the frame in the input stream, -1 if this information in
|
||
unavailable and/or meaningless (for example in case of synthetic audio)
|
||
|
||
@item fmt
|
||
The sample format.
|
||
|
||
@item chlayout
|
||
The channel layout.
|
||
|
||
@item rate
|
||
The sample rate for the audio frame.
|
||
|
||
@item nb_samples
|
||
The number of samples (per channel) in the frame.
|
||
|
||
@item checksum
|
||
The Adler-32 checksum (printed in hexadecimal) of the audio data. For planar
|
||
audio, the data is treated as if all the planes were concatenated.
|
||
|
||
@item plane_checksums
|
||
A list of Adler-32 checksums for each data plane.
|
||
@end table
|
||
|
||
@anchor{astats}
|
||
@section astats
|
||
|
||
Display time domain statistical information about the audio channels.
|
||
Statistics are calculated and displayed for each audio channel and,
|
||
where applicable, an overall figure is also given.
|
||
|
||
It accepts the following option:
|
||
@table @option
|
||
@item length
|
||
Short window length in seconds, used for peak and trough RMS measurement.
|
||
Default is @code{0.05} (50 milliseconds). Allowed range is @code{[0.1 - 10]}.
|
||
|
||
@item metadata
|
||
|
||
Set metadata injection. All the metadata keys are prefixed with @code{lavfi.astats.X},
|
||
where @code{X} is channel number starting from 1 or string @code{Overall}. Default is
|
||
disabled.
|
||
|
||
Available keys for each channel are:
|
||
DC_offset
|
||
Min_level
|
||
Max_level
|
||
Min_difference
|
||
Max_difference
|
||
Mean_difference
|
||
RMS_difference
|
||
Peak_level
|
||
RMS_peak
|
||
RMS_trough
|
||
Crest_factor
|
||
Flat_factor
|
||
Peak_count
|
||
Bit_depth
|
||
Dynamic_range
|
||
|
||
and for Overall:
|
||
DC_offset
|
||
Min_level
|
||
Max_level
|
||
Min_difference
|
||
Max_difference
|
||
Mean_difference
|
||
RMS_difference
|
||
Peak_level
|
||
RMS_level
|
||
RMS_peak
|
||
RMS_trough
|
||
Flat_factor
|
||
Peak_count
|
||
Bit_depth
|
||
Number_of_samples
|
||
|
||
For example full key look like this @code{lavfi.astats.1.DC_offset} or
|
||
this @code{lavfi.astats.Overall.Peak_count}.
|
||
|
||
For description what each key means read below.
|
||
|
||
@item reset
|
||
Set number of frame after which stats are going to be recalculated.
|
||
Default is disabled.
|
||
@end table
|
||
|
||
A description of each shown parameter follows:
|
||
|
||
@table @option
|
||
@item DC offset
|
||
Mean amplitude displacement from zero.
|
||
|
||
@item Min level
|
||
Minimal sample level.
|
||
|
||
@item Max level
|
||
Maximal sample level.
|
||
|
||
@item Min difference
|
||
Minimal difference between two consecutive samples.
|
||
|
||
@item Max difference
|
||
Maximal difference between two consecutive samples.
|
||
|
||
@item Mean difference
|
||
Mean difference between two consecutive samples.
|
||
The average of each difference between two consecutive samples.
|
||
|
||
@item RMS difference
|
||
Root Mean Square difference between two consecutive samples.
|
||
|
||
@item Peak level dB
|
||
@item RMS level dB
|
||
Standard peak and RMS level measured in dBFS.
|
||
|
||
@item RMS peak dB
|
||
@item RMS trough dB
|
||
Peak and trough values for RMS level measured over a short window.
|
||
|
||
@item Crest factor
|
||
Standard ratio of peak to RMS level (note: not in dB).
|
||
|
||
@item Flat factor
|
||
Flatness (i.e. consecutive samples with the same value) of the signal at its peak levels
|
||
(i.e. either @var{Min level} or @var{Max level}).
|
||
|
||
@item Peak count
|
||
Number of occasions (not the number of samples) that the signal attained either
|
||
@var{Min level} or @var{Max level}.
|
||
|
||
@item Bit depth
|
||
Overall bit depth of audio. Number of bits used for each sample.
|
||
|
||
@item Dynamic range
|
||
Measured dynamic range of audio in dB.
|
||
@end table
|
||
|
||
@section atempo
|
||
|
||
Adjust audio tempo.
|
||
|
||
The filter accepts exactly one parameter, the audio tempo. If not
|
||
specified then the filter will assume nominal 1.0 tempo. Tempo must
|
||
be in the [0.5, 2.0] range.
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Slow down audio to 80% tempo:
|
||
@example
|
||
atempo=0.8
|
||
@end example
|
||
|
||
@item
|
||
To speed up audio to 125% tempo:
|
||
@example
|
||
atempo=1.25
|
||
@end example
|
||
@end itemize
|
||
|
||
@section atrim
|
||
|
||
Trim the input so that the output contains one continuous subpart of the input.
|
||
|
||
It accepts the following parameters:
|
||
@table @option
|
||
@item start
|
||
Timestamp (in seconds) of the start of the section to keep. I.e. the audio
|
||
sample with the timestamp @var{start} will be the first sample in the output.
|
||
|
||
@item end
|
||
Specify time of the first audio sample that will be dropped, i.e. the
|
||
audio sample immediately preceding the one with the timestamp @var{end} will be
|
||
the last sample in the output.
|
||
|
||
@item start_pts
|
||
Same as @var{start}, except this option sets the start timestamp in samples
|
||
instead of seconds.
|
||
|
||
@item end_pts
|
||
Same as @var{end}, except this option sets the end timestamp in samples instead
|
||
of seconds.
|
||
|
||
@item duration
|
||
The maximum duration of the output in seconds.
|
||
|
||
@item start_sample
|
||
The number of the first sample that should be output.
|
||
|
||
@item end_sample
|
||
The number of the first sample that should be dropped.
|
||
@end table
|
||
|
||
@option{start}, @option{end}, and @option{duration} are expressed as time
|
||
duration specifications; see
|
||
@ref{time duration syntax,,the Time duration section in the ffmpeg-utils(1) manual,ffmpeg-utils}.
|
||
|
||
Note that the first two sets of the start/end options and the @option{duration}
|
||
option look at the frame timestamp, while the _sample options simply count the
|
||
samples that pass through the filter. So start/end_pts and start/end_sample will
|
||
give different results when the timestamps are wrong, inexact or do not start at
|
||
zero. Also note that this filter does not modify the timestamps. If you wish
|
||
to have the output timestamps start at zero, insert the asetpts filter after the
|
||
atrim filter.
|
||
|
||
If multiple start or end options are set, this filter tries to be greedy and
|
||
keep all samples that match at least one of the specified constraints. To keep
|
||
only the part that matches all the constraints at once, chain multiple atrim
|
||
filters.
|
||
|
||
The defaults are such that all the input is kept. So it is possible to set e.g.
|
||
just the end values to keep everything before the specified time.
|
||
|
||
Examples:
|
||
@itemize
|
||
@item
|
||
Drop everything except the second minute of input:
|
||
@example
|
||
ffmpeg -i INPUT -af atrim=60:120
|
||
@end example
|
||
|
||
@item
|
||
Keep only the first 1000 samples:
|
||
@example
|
||
ffmpeg -i INPUT -af atrim=end_sample=1000
|
||
@end example
|
||
|
||
@end itemize
|
||
|
||
@section bandpass
|
||
|
||
Apply a two-pole Butterworth band-pass filter with central
|
||
frequency @var{frequency}, and (3dB-point) band-width width.
|
||
The @var{csg} option selects a constant skirt gain (peak gain = Q)
|
||
instead of the default: constant 0dB peak gain.
|
||
The filter roll off at 6dB per octave (20dB per decade).
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item frequency, f
|
||
Set the filter's central frequency. Default is @code{3000}.
|
||
|
||
@item csg
|
||
Constant skirt gain if set to 1. Defaults to 0.
|
||
|
||
@item width_type, t
|
||
Set method to specify band-width of filter.
|
||
@table @option
|
||
@item h
|
||
Hz
|
||
@item q
|
||
Q-Factor
|
||
@item o
|
||
octave
|
||
@item s
|
||
slope
|
||
@end table
|
||
|
||
@item width, w
|
||
Specify the band-width of a filter in width_type units.
|
||
|
||
@item channels, c
|
||
Specify which channels to filter, by default all available are filtered.
|
||
@end table
|
||
|
||
@section bandreject
|
||
|
||
Apply a two-pole Butterworth band-reject filter with central
|
||
frequency @var{frequency}, and (3dB-point) band-width @var{width}.
|
||
The filter roll off at 6dB per octave (20dB per decade).
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item frequency, f
|
||
Set the filter's central frequency. Default is @code{3000}.
|
||
|
||
@item width_type, t
|
||
Set method to specify band-width of filter.
|
||
@table @option
|
||
@item h
|
||
Hz
|
||
@item q
|
||
Q-Factor
|
||
@item o
|
||
octave
|
||
@item s
|
||
slope
|
||
@end table
|
||
|
||
@item width, w
|
||
Specify the band-width of a filter in width_type units.
|
||
|
||
@item channels, c
|
||
Specify which channels to filter, by default all available are filtered.
|
||
@end table
|
||
|
||
@section bass
|
||
|
||
Boost or cut the bass (lower) frequencies of the audio using a two-pole
|
||
shelving filter with a response similar to that of a standard
|
||
hi-fi's tone-controls. This is also known as shelving equalisation (EQ).
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item gain, g
|
||
Give the gain at 0 Hz. Its useful range is about -20
|
||
(for a large cut) to +20 (for a large boost).
|
||
Beware of clipping when using a positive gain.
|
||
|
||
@item frequency, f
|
||
Set the filter's central frequency and so can be used
|
||
to extend or reduce the frequency range to be boosted or cut.
|
||
The default value is @code{100} Hz.
|
||
|
||
@item width_type, t
|
||
Set method to specify band-width of filter.
|
||
@table @option
|
||
@item h
|
||
Hz
|
||
@item q
|
||
Q-Factor
|
||
@item o
|
||
octave
|
||
@item s
|
||
slope
|
||
@end table
|
||
|
||
@item width, w
|
||
Determine how steep is the filter's shelf transition.
|
||
|
||
@item channels, c
|
||
Specify which channels to filter, by default all available are filtered.
|
||
@end table
|
||
|
||
@section biquad
|
||
|
||
Apply a biquad IIR filter with the given coefficients.
|
||
Where @var{b0}, @var{b1}, @var{b2} and @var{a0}, @var{a1}, @var{a2}
|
||
are the numerator and denominator coefficients respectively.
|
||
and @var{channels}, @var{c} specify which channels to filter, by default all
|
||
available are filtered.
|
||
|
||
@section bs2b
|
||
Bauer stereo to binaural transformation, which improves headphone listening of
|
||
stereo audio records.
|
||
|
||
To enable compilation of this filter you need to configure FFmpeg with
|
||
@code{--enable-libbs2b}.
|
||
|
||
It accepts the following parameters:
|
||
@table @option
|
||
|
||
@item profile
|
||
Pre-defined crossfeed level.
|
||
@table @option
|
||
|
||
@item default
|
||
Default level (fcut=700, feed=50).
|
||
|
||
@item cmoy
|
||
Chu Moy circuit (fcut=700, feed=60).
|
||
|
||
@item jmeier
|
||
Jan Meier circuit (fcut=650, feed=95).
|
||
|
||
@end table
|
||
|
||
@item fcut
|
||
Cut frequency (in Hz).
|
||
|
||
@item feed
|
||
Feed level (in Hz).
|
||
|
||
@end table
|
||
|
||
@section channelmap
|
||
|
||
Remap input channels to new locations.
|
||
|
||
It accepts the following parameters:
|
||
@table @option
|
||
@item map
|
||
Map channels from input to output. The argument is a '|'-separated list of
|
||
mappings, each in the @code{@var{in_channel}-@var{out_channel}} or
|
||
@var{in_channel} form. @var{in_channel} can be either the name of the input
|
||
channel (e.g. FL for front left) or its index in the input channel layout.
|
||
@var{out_channel} is the name of the output channel or its index in the output
|
||
channel layout. If @var{out_channel} is not given then it is implicitly an
|
||
index, starting with zero and increasing by one for each mapping.
|
||
|
||
@item channel_layout
|
||
The channel layout of the output stream.
|
||
@end table
|
||
|
||
If no mapping is present, the filter will implicitly map input channels to
|
||
output channels, preserving indices.
|
||
|
||
For example, assuming a 5.1+downmix input MOV file,
|
||
@example
|
||
ffmpeg -i in.mov -filter 'channelmap=map=DL-FL|DR-FR' out.wav
|
||
@end example
|
||
will create an output WAV file tagged as stereo from the downmix channels of
|
||
the input.
|
||
|
||
To fix a 5.1 WAV improperly encoded in AAC's native channel order
|
||
@example
|
||
ffmpeg -i in.wav -filter 'channelmap=1|2|0|5|3|4:5.1' out.wav
|
||
@end example
|
||
|
||
@section channelsplit
|
||
|
||
Split each channel from an input audio stream into a separate output stream.
|
||
|
||
It accepts the following parameters:
|
||
@table @option
|
||
@item channel_layout
|
||
The channel layout of the input stream. The default is "stereo".
|
||
@end table
|
||
|
||
For example, assuming a stereo input MP3 file,
|
||
@example
|
||
ffmpeg -i in.mp3 -filter_complex channelsplit out.mkv
|
||
@end example
|
||
will create an output Matroska file with two audio streams, one containing only
|
||
the left channel and the other the right channel.
|
||
|
||
Split a 5.1 WAV file into per-channel files:
|
||
@example
|
||
ffmpeg -i in.wav -filter_complex
|
||
'channelsplit=channel_layout=5.1[FL][FR][FC][LFE][SL][SR]'
|
||
-map '[FL]' front_left.wav -map '[FR]' front_right.wav -map '[FC]'
|
||
front_center.wav -map '[LFE]' lfe.wav -map '[SL]' side_left.wav -map '[SR]'
|
||
side_right.wav
|
||
@end example
|
||
|
||
@section chorus
|
||
Add a chorus effect to the audio.
|
||
|
||
Can make a single vocal sound like a chorus, but can also be applied to instrumentation.
|
||
|
||
Chorus resembles an echo effect with a short delay, but whereas with echo the delay is
|
||
constant, with chorus, it is varied using using sinusoidal or triangular modulation.
|
||
The modulation depth defines the range the modulated delay is played before or after
|
||
the delay. Hence the delayed sound will sound slower or faster, that is the delayed
|
||
sound tuned around the original one, like in a chorus where some vocals are slightly
|
||
off key.
|
||
|
||
It accepts the following parameters:
|
||
@table @option
|
||
@item in_gain
|
||
Set input gain. Default is 0.4.
|
||
|
||
@item out_gain
|
||
Set output gain. Default is 0.4.
|
||
|
||
@item delays
|
||
Set delays. A typical delay is around 40ms to 60ms.
|
||
|
||
@item decays
|
||
Set decays.
|
||
|
||
@item speeds
|
||
Set speeds.
|
||
|
||
@item depths
|
||
Set depths.
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
A single delay:
|
||
@example
|
||
chorus=0.7:0.9:55:0.4:0.25:2
|
||
@end example
|
||
|
||
@item
|
||
Two delays:
|
||
@example
|
||
chorus=0.6:0.9:50|60:0.4|0.32:0.25|0.4:2|1.3
|
||
@end example
|
||
|
||
@item
|
||
Fuller sounding chorus with three delays:
|
||
@example
|
||
chorus=0.5:0.9:50|60|40:0.4|0.32|0.3:0.25|0.4|0.3:2|2.3|1.3
|
||
@end example
|
||
@end itemize
|
||
|
||
@section compand
|
||
Compress or expand the audio's dynamic range.
|
||
|
||
It accepts the following parameters:
|
||
|
||
@table @option
|
||
|
||
@item attacks
|
||
@item decays
|
||
A list of times in seconds for each channel over which the instantaneous level
|
||
of the input signal is averaged to determine its volume. @var{attacks} refers to
|
||
increase of volume and @var{decays} refers to decrease of volume. For most
|
||
situations, the attack time (response to the audio getting louder) should be
|
||
shorter than the decay time, because the human ear is more sensitive to sudden
|
||
loud audio than sudden soft audio. A typical value for attack is 0.3 seconds and
|
||
a typical value for decay is 0.8 seconds.
|
||
If specified number of attacks & decays is lower than number of channels, the last
|
||
set attack/decay will be used for all remaining channels.
|
||
|
||
@item points
|
||
A list of points for the transfer function, specified in dB relative to the
|
||
maximum possible signal amplitude. Each key points list must be defined using
|
||
the following syntax: @code{x0/y0|x1/y1|x2/y2|....} or
|
||
@code{x0/y0 x1/y1 x2/y2 ....}
|
||
|
||
The input values must be in strictly increasing order but the transfer function
|
||
does not have to be monotonically rising. The point @code{0/0} is assumed but
|
||
may be overridden (by @code{0/out-dBn}). Typical values for the transfer
|
||
function are @code{-70/-70|-60/-20|1/0}.
|
||
|
||
@item soft-knee
|
||
Set the curve radius in dB for all joints. It defaults to 0.01.
|
||
|
||
@item gain
|
||
Set the additional gain in dB to be applied at all points on the transfer
|
||
function. This allows for easy adjustment of the overall gain.
|
||
It defaults to 0.
|
||
|
||
@item volume
|
||
Set an initial volume, in dB, to be assumed for each channel when filtering
|
||
starts. This permits the user to supply a nominal level initially, so that, for
|
||
example, a very large gain is not applied to initial signal levels before the
|
||
companding has begun to operate. A typical value for audio which is initially
|
||
quiet is -90 dB. It defaults to 0.
|
||
|
||
@item delay
|
||
Set a delay, in seconds. The input audio is analyzed immediately, but audio is
|
||
delayed before being fed to the volume adjuster. Specifying a delay
|
||
approximately equal to the attack/decay times allows the filter to effectively
|
||
operate in predictive rather than reactive mode. It defaults to 0.
|
||
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Make music with both quiet and loud passages suitable for listening to in a
|
||
noisy environment:
|
||
@example
|
||
compand=.3|.3:1|1:-90/-60|-60/-40|-40/-30|-20/-20:6:0:-90:0.2
|
||
@end example
|
||
|
||
Another example for audio with whisper and explosion parts:
|
||
@example
|
||
compand=0|0:1|1:-90/-900|-70/-70|-30/-9|0/-3:6:0:0:0
|
||
@end example
|
||
|
||
@item
|
||
A noise gate for when the noise is at a lower level than the signal:
|
||
@example
|
||
compand=.1|.1:.2|.2:-900/-900|-50.1/-900|-50/-50:.01:0:-90:.1
|
||
@end example
|
||
|
||
@item
|
||
Here is another noise gate, this time for when the noise is at a higher level
|
||
than the signal (making it, in some ways, similar to squelch):
|
||
@example
|
||
compand=.1|.1:.1|.1:-45.1/-45.1|-45/-900|0/-900:.01:45:-90:.1
|
||
@end example
|
||
|
||
@item
|
||
2:1 compression starting at -6dB:
|
||
@example
|
||
compand=points=-80/-80|-6/-6|0/-3.8|20/3.5
|
||
@end example
|
||
|
||
@item
|
||
2:1 compression starting at -9dB:
|
||
@example
|
||
compand=points=-80/-80|-9/-9|0/-5.3|20/2.9
|
||
@end example
|
||
|
||
@item
|
||
2:1 compression starting at -12dB:
|
||
@example
|
||
compand=points=-80/-80|-12/-12|0/-6.8|20/1.9
|
||
@end example
|
||
|
||
@item
|
||
2:1 compression starting at -18dB:
|
||
@example
|
||
compand=points=-80/-80|-18/-18|0/-9.8|20/0.7
|
||
@end example
|
||
|
||
@item
|
||
3:1 compression starting at -15dB:
|
||
@example
|
||
compand=points=-80/-80|-15/-15|0/-10.8|20/-5.2
|
||
@end example
|
||
|
||
@item
|
||
Compressor/Gate:
|
||
@example
|
||
compand=points=-80/-105|-62/-80|-15.4/-15.4|0/-12|20/-7.6
|
||
@end example
|
||
|
||
@item
|
||
Expander:
|
||
@example
|
||
compand=attacks=0:points=-80/-169|-54/-80|-49.5/-64.6|-41.1/-41.1|-25.8/-15|-10.8/-4.5|0/0|20/8.3
|
||
@end example
|
||
|
||
@item
|
||
Hard limiter at -6dB:
|
||
@example
|
||
compand=attacks=0:points=-80/-80|-6/-6|20/-6
|
||
@end example
|
||
|
||
@item
|
||
Hard limiter at -12dB:
|
||
@example
|
||
compand=attacks=0:points=-80/-80|-12/-12|20/-12
|
||
@end example
|
||
|
||
@item
|
||
Hard noise gate at -35 dB:
|
||
@example
|
||
compand=attacks=0:points=-80/-115|-35.1/-80|-35/-35|20/20
|
||
@end example
|
||
|
||
@item
|
||
Soft limiter:
|
||
@example
|
||
compand=attacks=0:points=-80/-80|-12.4/-12.4|-6/-8|0/-6.8|20/-2.8
|
||
@end example
|
||
@end itemize
|
||
|
||
@section compensationdelay
|
||
|
||
Compensation Delay Line is a metric based delay to compensate differing
|
||
positions of microphones or speakers.
|
||
|
||
For example, you have recorded guitar with two microphones placed in
|
||
different location. Because the front of sound wave has fixed speed in
|
||
normal conditions, the phasing of microphones can vary and depends on
|
||
their location and interposition. The best sound mix can be achieved when
|
||
these microphones are in phase (synchronized). Note that distance of
|
||
~30 cm between microphones makes one microphone to capture signal in
|
||
antiphase to another microphone. That makes the final mix sounding moody.
|
||
This filter helps to solve phasing problems by adding different delays
|
||
to each microphone track and make them synchronized.
|
||
|
||
The best result can be reached when you take one track as base and
|
||
synchronize other tracks one by one with it.
|
||
Remember that synchronization/delay tolerance depends on sample rate, too.
|
||
Higher sample rates will give more tolerance.
|
||
|
||
It accepts the following parameters:
|
||
|
||
@table @option
|
||
@item mm
|
||
Set millimeters distance. This is compensation distance for fine tuning.
|
||
Default is 0.
|
||
|
||
@item cm
|
||
Set cm distance. This is compensation distance for tightening distance setup.
|
||
Default is 0.
|
||
|
||
@item m
|
||
Set meters distance. This is compensation distance for hard distance setup.
|
||
Default is 0.
|
||
|
||
@item dry
|
||
Set dry amount. Amount of unprocessed (dry) signal.
|
||
Default is 0.
|
||
|
||
@item wet
|
||
Set wet amount. Amount of processed (wet) signal.
|
||
Default is 1.
|
||
|
||
@item temp
|
||
Set temperature degree in Celsius. This is the temperature of the environment.
|
||
Default is 20.
|
||
@end table
|
||
|
||
@section crossfeed
|
||
Apply headphone crossfeed filter.
|
||
|
||
Crossfeed is the process of blending the left and right channels of stereo
|
||
audio recording.
|
||
It is mainly used to reduce extreme stereo separation of low frequencies.
|
||
|
||
The intent is to produce more speaker like sound to the listener.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item strength
|
||
Set strength of crossfeed. Default is 0.2. Allowed range is from 0 to 1.
|
||
This sets gain of low shelf filter for side part of stereo image.
|
||
Default is -6dB. Max allowed is -30db when strength is set to 1.
|
||
|
||
@item range
|
||
Set soundstage wideness. Default is 0.5. Allowed range is from 0 to 1.
|
||
This sets cut off frequency of low shelf filter. Default is cut off near
|
||
1550 Hz. With range set to 1 cut off frequency is set to 2100 Hz.
|
||
|
||
@item level_in
|
||
Set input gain. Default is 0.9.
|
||
|
||
@item level_out
|
||
Set output gain. Default is 1.
|
||
@end table
|
||
|
||
@section crystalizer
|
||
Simple algorithm to expand audio dynamic range.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item i
|
||
Sets the intensity of effect (default: 2.0). Must be in range between 0.0
|
||
(unchanged sound) to 10.0 (maximum effect).
|
||
|
||
@item c
|
||
Enable clipping. By default is enabled.
|
||
@end table
|
||
|
||
@section dcshift
|
||
Apply a DC shift to the audio.
|
||
|
||
This can be useful to remove a DC offset (caused perhaps by a hardware problem
|
||
in the recording chain) from the audio. The effect of a DC offset is reduced
|
||
headroom and hence volume. The @ref{astats} filter can be used to determine if
|
||
a signal has a DC offset.
|
||
|
||
@table @option
|
||
@item shift
|
||
Set the DC shift, allowed range is [-1, 1]. It indicates the amount to shift
|
||
the audio.
|
||
|
||
@item limitergain
|
||
Optional. It should have a value much less than 1 (e.g. 0.05 or 0.02) and is
|
||
used to prevent clipping.
|
||
@end table
|
||
|
||
@section dynaudnorm
|
||
Dynamic Audio Normalizer.
|
||
|
||
This filter applies a certain amount of gain to the input audio in order
|
||
to bring its peak magnitude to a target level (e.g. 0 dBFS). However, in
|
||
contrast to more "simple" normalization algorithms, the Dynamic Audio
|
||
Normalizer *dynamically* re-adjusts the gain factor to the input audio.
|
||
This allows for applying extra gain to the "quiet" sections of the audio
|
||
while avoiding distortions or clipping the "loud" sections. In other words:
|
||
The Dynamic Audio Normalizer will "even out" the volume of quiet and loud
|
||
sections, in the sense that the volume of each section is brought to the
|
||
same target level. Note, however, that the Dynamic Audio Normalizer achieves
|
||
this goal *without* applying "dynamic range compressing". It will retain 100%
|
||
of the dynamic range *within* each section of the audio file.
|
||
|
||
@table @option
|
||
@item f
|
||
Set the frame length in milliseconds. In range from 10 to 8000 milliseconds.
|
||
Default is 500 milliseconds.
|
||
The Dynamic Audio Normalizer processes the input audio in small chunks,
|
||
referred to as frames. This is required, because a peak magnitude has no
|
||
meaning for just a single sample value. Instead, we need to determine the
|
||
peak magnitude for a contiguous sequence of sample values. While a "standard"
|
||
normalizer would simply use the peak magnitude of the complete file, the
|
||
Dynamic Audio Normalizer determines the peak magnitude individually for each
|
||
frame. The length of a frame is specified in milliseconds. By default, the
|
||
Dynamic Audio Normalizer uses a frame length of 500 milliseconds, which has
|
||
been found to give good results with most files.
|
||
Note that the exact frame length, in number of samples, will be determined
|
||
automatically, based on the sampling rate of the individual input audio file.
|
||
|
||
@item g
|
||
Set the Gaussian filter window size. In range from 3 to 301, must be odd
|
||
number. Default is 31.
|
||
Probably the most important parameter of the Dynamic Audio Normalizer is the
|
||
@code{window size} of the Gaussian smoothing filter. The filter's window size
|
||
is specified in frames, centered around the current frame. For the sake of
|
||
simplicity, this must be an odd number. Consequently, the default value of 31
|
||
takes into account the current frame, as well as the 15 preceding frames and
|
||
the 15 subsequent frames. Using a larger window results in a stronger
|
||
smoothing effect and thus in less gain variation, i.e. slower gain
|
||
adaptation. Conversely, using a smaller window results in a weaker smoothing
|
||
effect and thus in more gain variation, i.e. faster gain adaptation.
|
||
In other words, the more you increase this value, the more the Dynamic Audio
|
||
Normalizer will behave like a "traditional" normalization filter. On the
|
||
contrary, the more you decrease this value, the more the Dynamic Audio
|
||
Normalizer will behave like a dynamic range compressor.
|
||
|
||
@item p
|
||
Set the target peak value. This specifies the highest permissible magnitude
|
||
level for the normalized audio input. This filter will try to approach the
|
||
target peak magnitude as closely as possible, but at the same time it also
|
||
makes sure that the normalized signal will never exceed the peak magnitude.
|
||
A frame's maximum local gain factor is imposed directly by the target peak
|
||
magnitude. The default value is 0.95 and thus leaves a headroom of 5%*.
|
||
It is not recommended to go above this value.
|
||
|
||
@item m
|
||
Set the maximum gain factor. In range from 1.0 to 100.0. Default is 10.0.
|
||
The Dynamic Audio Normalizer determines the maximum possible (local) gain
|
||
factor for each input frame, i.e. the maximum gain factor that does not
|
||
result in clipping or distortion. The maximum gain factor is determined by
|
||
the frame's highest magnitude sample. However, the Dynamic Audio Normalizer
|
||
additionally bounds the frame's maximum gain factor by a predetermined
|
||
(global) maximum gain factor. This is done in order to avoid excessive gain
|
||
factors in "silent" or almost silent frames. By default, the maximum gain
|
||
factor is 10.0, For most inputs the default value should be sufficient and
|
||
it usually is not recommended to increase this value. Though, for input
|
||
with an extremely low overall volume level, it may be necessary to allow even
|
||
higher gain factors. Note, however, that the Dynamic Audio Normalizer does
|
||
not simply apply a "hard" threshold (i.e. cut off values above the threshold).
|
||
Instead, a "sigmoid" threshold function will be applied. This way, the
|
||
gain factors will smoothly approach the threshold value, but never exceed that
|
||
value.
|
||
|
||
@item r
|
||
Set the target RMS. In range from 0.0 to 1.0. Default is 0.0 - disabled.
|
||
By default, the Dynamic Audio Normalizer performs "peak" normalization.
|
||
This means that the maximum local gain factor for each frame is defined
|
||
(only) by the frame's highest magnitude sample. This way, the samples can
|
||
be amplified as much as possible without exceeding the maximum signal
|
||
level, i.e. without clipping. Optionally, however, the Dynamic Audio
|
||
Normalizer can also take into account the frame's root mean square,
|
||
abbreviated RMS. In electrical engineering, the RMS is commonly used to
|
||
determine the power of a time-varying signal. It is therefore considered
|
||
that the RMS is a better approximation of the "perceived loudness" than
|
||
just looking at the signal's peak magnitude. Consequently, by adjusting all
|
||
frames to a constant RMS value, a uniform "perceived loudness" can be
|
||
established. If a target RMS value has been specified, a frame's local gain
|
||
factor is defined as the factor that would result in exactly that RMS value.
|
||
Note, however, that the maximum local gain factor is still restricted by the
|
||
frame's highest magnitude sample, in order to prevent clipping.
|
||
|
||
@item n
|
||
Enable channels coupling. By default is enabled.
|
||
By default, the Dynamic Audio Normalizer will amplify all channels by the same
|
||
amount. This means the same gain factor will be applied to all channels, i.e.
|
||
the maximum possible gain factor is determined by the "loudest" channel.
|
||
However, in some recordings, it may happen that the volume of the different
|
||
channels is uneven, e.g. one channel may be "quieter" than the other one(s).
|
||
In this case, this option can be used to disable the channel coupling. This way,
|
||
the gain factor will be determined independently for each channel, depending
|
||
only on the individual channel's highest magnitude sample. This allows for
|
||
harmonizing the volume of the different channels.
|
||
|
||
@item c
|
||
Enable DC bias correction. By default is disabled.
|
||
An audio signal (in the time domain) is a sequence of sample values.
|
||
In the Dynamic Audio Normalizer these sample values are represented in the
|
||
-1.0 to 1.0 range, regardless of the original input format. Normally, the
|
||
audio signal, or "waveform", should be centered around the zero point.
|
||
That means if we calculate the mean value of all samples in a file, or in a
|
||
single frame, then the result should be 0.0 or at least very close to that
|
||
value. If, however, there is a significant deviation of the mean value from
|
||
0.0, in either positive or negative direction, this is referred to as a
|
||
DC bias or DC offset. Since a DC bias is clearly undesirable, the Dynamic
|
||
Audio Normalizer provides optional DC bias correction.
|
||
With DC bias correction enabled, the Dynamic Audio Normalizer will determine
|
||
the mean value, or "DC correction" offset, of each input frame and subtract
|
||
that value from all of the frame's sample values which ensures those samples
|
||
are centered around 0.0 again. Also, in order to avoid "gaps" at the frame
|
||
boundaries, the DC correction offset values will be interpolated smoothly
|
||
between neighbouring frames.
|
||
|
||
@item b
|
||
Enable alternative boundary mode. By default is disabled.
|
||
The Dynamic Audio Normalizer takes into account a certain neighbourhood
|
||
around each frame. This includes the preceding frames as well as the
|
||
subsequent frames. However, for the "boundary" frames, located at the very
|
||
beginning and at the very end of the audio file, not all neighbouring
|
||
frames are available. In particular, for the first few frames in the audio
|
||
file, the preceding frames are not known. And, similarly, for the last few
|
||
frames in the audio file, the subsequent frames are not known. Thus, the
|
||
question arises which gain factors should be assumed for the missing frames
|
||
in the "boundary" region. The Dynamic Audio Normalizer implements two modes
|
||
to deal with this situation. The default boundary mode assumes a gain factor
|
||
of exactly 1.0 for the missing frames, resulting in a smooth "fade in" and
|
||
"fade out" at the beginning and at the end of the input, respectively.
|
||
|
||
@item s
|
||
Set the compress factor. In range from 0.0 to 30.0. Default is 0.0.
|
||
By default, the Dynamic Audio Normalizer does not apply "traditional"
|
||
compression. This means that signal peaks will not be pruned and thus the
|
||
full dynamic range will be retained within each local neighbourhood. However,
|
||
in some cases it may be desirable to combine the Dynamic Audio Normalizer's
|
||
normalization algorithm with a more "traditional" compression.
|
||
For this purpose, the Dynamic Audio Normalizer provides an optional compression
|
||
(thresholding) function. If (and only if) the compression feature is enabled,
|
||
all input frames will be processed by a soft knee thresholding function prior
|
||
to the actual normalization process. Put simply, the thresholding function is
|
||
going to prune all samples whose magnitude exceeds a certain threshold value.
|
||
However, the Dynamic Audio Normalizer does not simply apply a fixed threshold
|
||
value. Instead, the threshold value will be adjusted for each individual
|
||
frame.
|
||
In general, smaller parameters result in stronger compression, and vice versa.
|
||
Values below 3.0 are not recommended, because audible distortion may appear.
|
||
@end table
|
||
|
||
@section earwax
|
||
|
||
Make audio easier to listen to on headphones.
|
||
|
||
This filter adds `cues' to 44.1kHz stereo (i.e. audio CD format) audio
|
||
so that when listened to on headphones the stereo image is moved from
|
||
inside your head (standard for headphones) to outside and in front of
|
||
the listener (standard for speakers).
|
||
|
||
Ported from SoX.
|
||
|
||
@section equalizer
|
||
|
||
Apply a two-pole peaking equalisation (EQ) filter. With this
|
||
filter, the signal-level at and around a selected frequency can
|
||
be increased or decreased, whilst (unlike bandpass and bandreject
|
||
filters) that at all other frequencies is unchanged.
|
||
|
||
In order to produce complex equalisation curves, this filter can
|
||
be given several times, each with a different central frequency.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item frequency, f
|
||
Set the filter's central frequency in Hz.
|
||
|
||
@item width_type, t
|
||
Set method to specify band-width of filter.
|
||
@table @option
|
||
@item h
|
||
Hz
|
||
@item q
|
||
Q-Factor
|
||
@item o
|
||
octave
|
||
@item s
|
||
slope
|
||
@end table
|
||
|
||
@item width, w
|
||
Specify the band-width of a filter in width_type units.
|
||
|
||
@item gain, g
|
||
Set the required gain or attenuation in dB.
|
||
Beware of clipping when using a positive gain.
|
||
|
||
@item channels, c
|
||
Specify which channels to filter, by default all available are filtered.
|
||
@end table
|
||
|
||
@subsection Examples
|
||
@itemize
|
||
@item
|
||
Attenuate 10 dB at 1000 Hz, with a bandwidth of 200 Hz:
|
||
@example
|
||
equalizer=f=1000:t=h:width=200:g=-10
|
||
@end example
|
||
|
||
@item
|
||
Apply 2 dB gain at 1000 Hz with Q 1 and attenuate 5 dB at 100 Hz with Q 2:
|
||
@example
|
||
equalizer=f=1000:t=q:w=1:g=2,equalizer=f=100:t=q:w=2:g=-5
|
||
@end example
|
||
@end itemize
|
||
|
||
@section extrastereo
|
||
|
||
Linearly increases the difference between left and right channels which
|
||
adds some sort of "live" effect to playback.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item m
|
||
Sets the difference coefficient (default: 2.5). 0.0 means mono sound
|
||
(average of both channels), with 1.0 sound will be unchanged, with
|
||
-1.0 left and right channels will be swapped.
|
||
|
||
@item c
|
||
Enable clipping. By default is enabled.
|
||
@end table
|
||
|
||
@section firequalizer
|
||
Apply FIR Equalization using arbitrary frequency response.
|
||
|
||
The filter accepts the following option:
|
||
|
||
@table @option
|
||
@item gain
|
||
Set gain curve equation (in dB). The expression can contain variables:
|
||
@table @option
|
||
@item f
|
||
the evaluated frequency
|
||
@item sr
|
||
sample rate
|
||
@item ch
|
||
channel number, set to 0 when multichannels evaluation is disabled
|
||
@item chid
|
||
channel id, see libavutil/channel_layout.h, set to the first channel id when
|
||
multichannels evaluation is disabled
|
||
@item chs
|
||
number of channels
|
||
@item chlayout
|
||
channel_layout, see libavutil/channel_layout.h
|
||
|
||
@end table
|
||
and functions:
|
||
@table @option
|
||
@item gain_interpolate(f)
|
||
interpolate gain on frequency f based on gain_entry
|
||
@item cubic_interpolate(f)
|
||
same as gain_interpolate, but smoother
|
||
@end table
|
||
This option is also available as command. Default is @code{gain_interpolate(f)}.
|
||
|
||
@item gain_entry
|
||
Set gain entry for gain_interpolate function. The expression can
|
||
contain functions:
|
||
@table @option
|
||
@item entry(f, g)
|
||
store gain entry at frequency f with value g
|
||
@end table
|
||
This option is also available as command.
|
||
|
||
@item delay
|
||
Set filter delay in seconds. Higher value means more accurate.
|
||
Default is @code{0.01}.
|
||
|
||
@item accuracy
|
||
Set filter accuracy in Hz. Lower value means more accurate.
|
||
Default is @code{5}.
|
||
|
||
@item wfunc
|
||
Set window function. Acceptable values are:
|
||
@table @option
|
||
@item rectangular
|
||
rectangular window, useful when gain curve is already smooth
|
||
@item hann
|
||
hann window (default)
|
||
@item hamming
|
||
hamming window
|
||
@item blackman
|
||
blackman window
|
||
@item nuttall3
|
||
3-terms continuous 1st derivative nuttall window
|
||
@item mnuttall3
|
||
minimum 3-terms discontinuous nuttall window
|
||
@item nuttall
|
||
4-terms continuous 1st derivative nuttall window
|
||
@item bnuttall
|
||
minimum 4-terms discontinuous nuttall (blackman-nuttall) window
|
||
@item bharris
|
||
blackman-harris window
|
||
@item tukey
|
||
tukey window
|
||
@end table
|
||
|
||
@item fixed
|
||
If enabled, use fixed number of audio samples. This improves speed when
|
||
filtering with large delay. Default is disabled.
|
||
|
||
@item multi
|
||
Enable multichannels evaluation on gain. Default is disabled.
|
||
|
||
@item zero_phase
|
||
Enable zero phase mode by subtracting timestamp to compensate delay.
|
||
Default is disabled.
|
||
|
||
@item scale
|
||
Set scale used by gain. Acceptable values are:
|
||
@table @option
|
||
@item linlin
|
||
linear frequency, linear gain
|
||
@item linlog
|
||
linear frequency, logarithmic (in dB) gain (default)
|
||
@item loglin
|
||
logarithmic (in octave scale where 20 Hz is 0) frequency, linear gain
|
||
@item loglog
|
||
logarithmic frequency, logarithmic gain
|
||
@end table
|
||
|
||
@item dumpfile
|
||
Set file for dumping, suitable for gnuplot.
|
||
|
||
@item dumpscale
|
||
Set scale for dumpfile. Acceptable values are same with scale option.
|
||
Default is linlog.
|
||
|
||
@item fft2
|
||
Enable 2-channel convolution using complex FFT. This improves speed significantly.
|
||
Default is disabled.
|
||
@end table
|
||
|
||
@subsection Examples
|
||
@itemize
|
||
@item
|
||
lowpass at 1000 Hz:
|
||
@example
|
||
firequalizer=gain='if(lt(f,1000), 0, -INF)'
|
||
@end example
|
||
@item
|
||
lowpass at 1000 Hz with gain_entry:
|
||
@example
|
||
firequalizer=gain_entry='entry(1000,0); entry(1001, -INF)'
|
||
@end example
|
||
@item
|
||
custom equalization:
|
||
@example
|
||
firequalizer=gain_entry='entry(100,0); entry(400, -4); entry(1000, -6); entry(2000, 0)'
|
||
@end example
|
||
@item
|
||
higher delay with zero phase to compensate delay:
|
||
@example
|
||
firequalizer=delay=0.1:fixed=on:zero_phase=on
|
||
@end example
|
||
@item
|
||
lowpass on left channel, highpass on right channel:
|
||
@example
|
||
firequalizer=gain='if(eq(chid,1), gain_interpolate(f), if(eq(chid,2), gain_interpolate(1e6+f), 0))'
|
||
:gain_entry='entry(1000, 0); entry(1001,-INF); entry(1e6+1000,0)':multi=on
|
||
@end example
|
||
@end itemize
|
||
|
||
@section flanger
|
||
Apply a flanging effect to the audio.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item delay
|
||
Set base delay in milliseconds. Range from 0 to 30. Default value is 0.
|
||
|
||
@item depth
|
||
Set added swep delay in milliseconds. Range from 0 to 10. Default value is 2.
|
||
|
||
@item regen
|
||
Set percentage regeneration (delayed signal feedback). Range from -95 to 95.
|
||
Default value is 0.
|
||
|
||
@item width
|
||
Set percentage of delayed signal mixed with original. Range from 0 to 100.
|
||
Default value is 71.
|
||
|
||
@item speed
|
||
Set sweeps per second (Hz). Range from 0.1 to 10. Default value is 0.5.
|
||
|
||
@item shape
|
||
Set swept wave shape, can be @var{triangular} or @var{sinusoidal}.
|
||
Default value is @var{sinusoidal}.
|
||
|
||
@item phase
|
||
Set swept wave percentage-shift for multi channel. Range from 0 to 100.
|
||
Default value is 25.
|
||
|
||
@item interp
|
||
Set delay-line interpolation, @var{linear} or @var{quadratic}.
|
||
Default is @var{linear}.
|
||
@end table
|
||
|
||
@section hdcd
|
||
|
||
Decodes High Definition Compatible Digital (HDCD) data. A 16-bit PCM stream with
|
||
embedded HDCD codes is expanded into a 20-bit PCM stream.
|
||
|
||
The filter supports the Peak Extend and Low-level Gain Adjustment features
|
||
of HDCD, and detects the Transient Filter flag.
|
||
|
||
@example
|
||
ffmpeg -i HDCD16.flac -af hdcd OUT24.flac
|
||
@end example
|
||
|
||
When using the filter with wav, note the default encoding for wav is 16-bit,
|
||
so the resulting 20-bit stream will be truncated back to 16-bit. Use something
|
||
like @command{-acodec pcm_s24le} after the filter to get 24-bit PCM output.
|
||
@example
|
||
ffmpeg -i HDCD16.wav -af hdcd OUT16.wav
|
||
ffmpeg -i HDCD16.wav -af hdcd -acodec pcm_s24le OUT24.wav
|
||
@end example
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item disable_autoconvert
|
||
Disable any automatic format conversion or resampling in the filter graph.
|
||
|
||
@item process_stereo
|
||
Process the stereo channels together. If target_gain does not match between
|
||
channels, consider it invalid and use the last valid target_gain.
|
||
|
||
@item cdt_ms
|
||
Set the code detect timer period in ms.
|
||
|
||
@item force_pe
|
||
Always extend peaks above -3dBFS even if PE isn't signaled.
|
||
|
||
@item analyze_mode
|
||
Replace audio with a solid tone and adjust the amplitude to signal some
|
||
specific aspect of the decoding process. The output file can be loaded in
|
||
an audio editor alongside the original to aid analysis.
|
||
|
||
@code{analyze_mode=pe:force_pe=true} can be used to see all samples above the PE level.
|
||
|
||
Modes are:
|
||
@table @samp
|
||
@item 0, off
|
||
Disabled
|
||
@item 1, lle
|
||
Gain adjustment level at each sample
|
||
@item 2, pe
|
||
Samples where peak extend occurs
|
||
@item 3, cdt
|
||
Samples where the code detect timer is active
|
||
@item 4, tgm
|
||
Samples where the target gain does not match between channels
|
||
@end table
|
||
@end table
|
||
|
||
@section headphone
|
||
|
||
Apply head-related transfer functions (HRTFs) to create virtual
|
||
loudspeakers around the user for binaural listening via headphones.
|
||
The HRIRs are provided via additional streams, for each channel
|
||
one stereo input stream is needed.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item map
|
||
Set mapping of input streams for convolution.
|
||
The argument is a '|'-separated list of channel names in order as they
|
||
are given as additional stream inputs for filter.
|
||
This also specify number of input streams. Number of input streams
|
||
must be not less than number of channels in first stream plus one.
|
||
|
||
@item gain
|
||
Set gain applied to audio. Value is in dB. Default is 0.
|
||
|
||
@item type
|
||
Set processing type. Can be @var{time} or @var{freq}. @var{time} is
|
||
processing audio in time domain which is slow.
|
||
@var{freq} is processing audio in frequency domain which is fast.
|
||
Default is @var{freq}.
|
||
|
||
@item lfe
|
||
Set custom gain for LFE channels. Value is in dB. Default is 0.
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Full example using wav files as coefficients with amovie filters for 7.1 downmix,
|
||
each amovie filter use stereo file with IR coefficients as input.
|
||
The files give coefficients for each position of virtual loudspeaker:
|
||
@example
|
||
ffmpeg -i input.wav -lavfi-complex "amovie=azi_270_ele_0_DFC.wav[sr],amovie=azi_90_ele_0_DFC.wav[sl],amovie=azi_225_ele_0_DFC.wav[br],amovie=azi_135_ele_0_DFC.wav[bl],amovie=azi_0_ele_0_DFC.wav,asplit[fc][lfe],amovie=azi_35_ele_0_DFC.wav[fl],amovie=azi_325_ele_0_DFC.wav[fr],[a:0][fl][fr][fc][lfe][bl][br][sl][sr]headphone=FL|FR|FC|LFE|BL|BR|SL|SR"
|
||
output.wav
|
||
@end example
|
||
@end itemize
|
||
|
||
@section highpass
|
||
|
||
Apply a high-pass filter with 3dB point frequency.
|
||
The filter can be either single-pole, or double-pole (the default).
|
||
The filter roll off at 6dB per pole per octave (20dB per pole per decade).
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item frequency, f
|
||
Set frequency in Hz. Default is 3000.
|
||
|
||
@item poles, p
|
||
Set number of poles. Default is 2.
|
||
|
||
@item width_type, t
|
||
Set method to specify band-width of filter.
|
||
@table @option
|
||
@item h
|
||
Hz
|
||
@item q
|
||
Q-Factor
|
||
@item o
|
||
octave
|
||
@item s
|
||
slope
|
||
@end table
|
||
|
||
@item width, w
|
||
Specify the band-width of a filter in width_type units.
|
||
Applies only to double-pole filter.
|
||
The default is 0.707q and gives a Butterworth response.
|
||
|
||
@item channels, c
|
||
Specify which channels to filter, by default all available are filtered.
|
||
@end table
|
||
|
||
@section join
|
||
|
||
Join multiple input streams into one multi-channel stream.
|
||
|
||
It accepts the following parameters:
|
||
@table @option
|
||
|
||
@item inputs
|
||
The number of input streams. It defaults to 2.
|
||
|
||
@item channel_layout
|
||
The desired output channel layout. It defaults to stereo.
|
||
|
||
@item map
|
||
Map channels from inputs to output. The argument is a '|'-separated list of
|
||
mappings, each in the @code{@var{input_idx}.@var{in_channel}-@var{out_channel}}
|
||
form. @var{input_idx} is the 0-based index of the input stream. @var{in_channel}
|
||
can be either the name of the input channel (e.g. FL for front left) or its
|
||
index in the specified input stream. @var{out_channel} is the name of the output
|
||
channel.
|
||
@end table
|
||
|
||
The filter will attempt to guess the mappings when they are not specified
|
||
explicitly. It does so by first trying to find an unused matching input channel
|
||
and if that fails it picks the first unused input channel.
|
||
|
||
Join 3 inputs (with properly set channel layouts):
|
||
@example
|
||
ffmpeg -i INPUT1 -i INPUT2 -i INPUT3 -filter_complex join=inputs=3 OUTPUT
|
||
@end example
|
||
|
||
Build a 5.1 output from 6 single-channel streams:
|
||
@example
|
||
ffmpeg -i fl -i fr -i fc -i sl -i sr -i lfe -filter_complex
|
||
'join=inputs=6:channel_layout=5.1:map=0.0-FL|1.0-FR|2.0-FC|3.0-SL|4.0-SR|5.0-LFE'
|
||
out
|
||
@end example
|
||
|
||
@section ladspa
|
||
|
||
Load a LADSPA (Linux Audio Developer's Simple Plugin API) plugin.
|
||
|
||
To enable compilation of this filter you need to configure FFmpeg with
|
||
@code{--enable-ladspa}.
|
||
|
||
@table @option
|
||
@item file, f
|
||
Specifies the name of LADSPA plugin library to load. If the environment
|
||
variable @env{LADSPA_PATH} is defined, the LADSPA plugin is searched in
|
||
each one of the directories specified by the colon separated list in
|
||
@env{LADSPA_PATH}, otherwise in the standard LADSPA paths, which are in
|
||
this order: @file{HOME/.ladspa/lib/}, @file{/usr/local/lib/ladspa/},
|
||
@file{/usr/lib/ladspa/}.
|
||
|
||
@item plugin, p
|
||
Specifies the plugin within the library. Some libraries contain only
|
||
one plugin, but others contain many of them. If this is not set filter
|
||
will list all available plugins within the specified library.
|
||
|
||
@item controls, c
|
||
Set the '|' separated list of controls which are zero or more floating point
|
||
values that determine the behavior of the loaded plugin (for example delay,
|
||
threshold or gain).
|
||
Controls need to be defined using the following syntax:
|
||
c0=@var{value0}|c1=@var{value1}|c2=@var{value2}|..., where
|
||
@var{valuei} is the value set on the @var{i}-th control.
|
||
Alternatively they can be also defined using the following syntax:
|
||
@var{value0}|@var{value1}|@var{value2}|..., where
|
||
@var{valuei} is the value set on the @var{i}-th control.
|
||
If @option{controls} is set to @code{help}, all available controls and
|
||
their valid ranges are printed.
|
||
|
||
@item sample_rate, s
|
||
Specify the sample rate, default to 44100. Only used if plugin have
|
||
zero inputs.
|
||
|
||
@item nb_samples, n
|
||
Set the number of samples per channel per each output frame, default
|
||
is 1024. Only used if plugin have zero inputs.
|
||
|
||
@item duration, d
|
||
Set the minimum duration of the sourced audio. See
|
||
@ref{time duration syntax,,the Time duration section in the ffmpeg-utils(1) manual,ffmpeg-utils}
|
||
for the accepted syntax.
|
||
Note that the resulting duration may be greater than the specified duration,
|
||
as the generated audio is always cut at the end of a complete frame.
|
||
If not specified, or the expressed duration is negative, the audio is
|
||
supposed to be generated forever.
|
||
Only used if plugin have zero inputs.
|
||
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
List all available plugins within amp (LADSPA example plugin) library:
|
||
@example
|
||
ladspa=file=amp
|
||
@end example
|
||
|
||
@item
|
||
List all available controls and their valid ranges for @code{vcf_notch}
|
||
plugin from @code{VCF} library:
|
||
@example
|
||
ladspa=f=vcf:p=vcf_notch:c=help
|
||
@end example
|
||
|
||
@item
|
||
Simulate low quality audio equipment using @code{Computer Music Toolkit} (CMT)
|
||
plugin library:
|
||
@example
|
||
ladspa=file=cmt:plugin=lofi:controls=c0=22|c1=12|c2=12
|
||
@end example
|
||
|
||
@item
|
||
Add reverberation to the audio using TAP-plugins
|
||
(Tom's Audio Processing plugins):
|
||
@example
|
||
ladspa=file=tap_reverb:tap_reverb
|
||
@end example
|
||
|
||
@item
|
||
Generate white noise, with 0.2 amplitude:
|
||
@example
|
||
ladspa=file=cmt:noise_source_white:c=c0=.2
|
||
@end example
|
||
|
||
@item
|
||
Generate 20 bpm clicks using plugin @code{C* Click - Metronome} from the
|
||
@code{C* Audio Plugin Suite} (CAPS) library:
|
||
@example
|
||
ladspa=file=caps:Click:c=c1=20'
|
||
@end example
|
||
|
||
@item
|
||
Apply @code{C* Eq10X2 - Stereo 10-band equaliser} effect:
|
||
@example
|
||
ladspa=caps:Eq10X2:c=c0=-48|c9=-24|c3=12|c4=2
|
||
@end example
|
||
|
||
@item
|
||
Increase volume by 20dB using fast lookahead limiter from Steve Harris
|
||
@code{SWH Plugins} collection:
|
||
@example
|
||
ladspa=fast_lookahead_limiter_1913:fastLookaheadLimiter:20|0|2
|
||
@end example
|
||
|
||
@item
|
||
Attenuate low frequencies using Multiband EQ from Steve Harris
|
||
@code{SWH Plugins} collection:
|
||
@example
|
||
ladspa=mbeq_1197:mbeq:-24|-24|-24|0|0|0|0|0|0|0|0|0|0|0|0
|
||
@end example
|
||
|
||
@item
|
||
Reduce stereo image using @code{Narrower} from the @code{C* Audio Plugin Suite}
|
||
(CAPS) library:
|
||
@example
|
||
ladspa=caps:Narrower
|
||
@end example
|
||
|
||
@item
|
||
Another white noise, now using @code{C* Audio Plugin Suite} (CAPS) library:
|
||
@example
|
||
ladspa=caps:White:.2
|
||
@end example
|
||
|
||
@item
|
||
Some fractal noise, using @code{C* Audio Plugin Suite} (CAPS) library:
|
||
@example
|
||
ladspa=caps:Fractal:c=c1=1
|
||
@end example
|
||
|
||
@item
|
||
Dynamic volume normalization using @code{VLevel} plugin:
|
||
@example
|
||
ladspa=vlevel-ladspa:vlevel_mono
|
||
@end example
|
||
@end itemize
|
||
|
||
@subsection Commands
|
||
|
||
This filter supports the following commands:
|
||
@table @option
|
||
@item cN
|
||
Modify the @var{N}-th control value.
|
||
|
||
If the specified value is not valid, it is ignored and prior one is kept.
|
||
@end table
|
||
|
||
@section loudnorm
|
||
|
||
EBU R128 loudness normalization. Includes both dynamic and linear normalization modes.
|
||
Support for both single pass (livestreams, files) and double pass (files) modes.
|
||
This algorithm can target IL, LRA, and maximum true peak.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item I, i
|
||
Set integrated loudness target.
|
||
Range is -70.0 - -5.0. Default value is -24.0.
|
||
|
||
@item LRA, lra
|
||
Set loudness range target.
|
||
Range is 1.0 - 20.0. Default value is 7.0.
|
||
|
||
@item TP, tp
|
||
Set maximum true peak.
|
||
Range is -9.0 - +0.0. Default value is -2.0.
|
||
|
||
@item measured_I, measured_i
|
||
Measured IL of input file.
|
||
Range is -99.0 - +0.0.
|
||
|
||
@item measured_LRA, measured_lra
|
||
Measured LRA of input file.
|
||
Range is 0.0 - 99.0.
|
||
|
||
@item measured_TP, measured_tp
|
||
Measured true peak of input file.
|
||
Range is -99.0 - +99.0.
|
||
|
||
@item measured_thresh
|
||
Measured threshold of input file.
|
||
Range is -99.0 - +0.0.
|
||
|
||
@item offset
|
||
Set offset gain. Gain is applied before the true-peak limiter.
|
||
Range is -99.0 - +99.0. Default is +0.0.
|
||
|
||
@item linear
|
||
Normalize linearly if possible.
|
||
measured_I, measured_LRA, measured_TP, and measured_thresh must also
|
||
to be specified in order to use this mode.
|
||
Options are true or false. Default is true.
|
||
|
||
@item dual_mono
|
||
Treat mono input files as "dual-mono". If a mono file is intended for playback
|
||
on a stereo system, its EBU R128 measurement will be perceptually incorrect.
|
||
If set to @code{true}, this option will compensate for this effect.
|
||
Multi-channel input files are not affected by this option.
|
||
Options are true or false. Default is false.
|
||
|
||
@item print_format
|
||
Set print format for stats. Options are summary, json, or none.
|
||
Default value is none.
|
||
@end table
|
||
|
||
@section lowpass
|
||
|
||
Apply a low-pass filter with 3dB point frequency.
|
||
The filter can be either single-pole or double-pole (the default).
|
||
The filter roll off at 6dB per pole per octave (20dB per pole per decade).
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item frequency, f
|
||
Set frequency in Hz. Default is 500.
|
||
|
||
@item poles, p
|
||
Set number of poles. Default is 2.
|
||
|
||
@item width_type, t
|
||
Set method to specify band-width of filter.
|
||
@table @option
|
||
@item h
|
||
Hz
|
||
@item q
|
||
Q-Factor
|
||
@item o
|
||
octave
|
||
@item s
|
||
slope
|
||
@end table
|
||
|
||
@item width, w
|
||
Specify the band-width of a filter in width_type units.
|
||
Applies only to double-pole filter.
|
||
The default is 0.707q and gives a Butterworth response.
|
||
|
||
@item channels, c
|
||
Specify which channels to filter, by default all available are filtered.
|
||
@end table
|
||
|
||
@subsection Examples
|
||
@itemize
|
||
@item
|
||
Lowpass only LFE channel, it LFE is not present it does nothing:
|
||
@example
|
||
lowpass=c=LFE
|
||
@end example
|
||
@end itemize
|
||
|
||
@anchor{pan}
|
||
@section pan
|
||
|
||
Mix channels with specific gain levels. The filter accepts the output
|
||
channel layout followed by a set of channels definitions.
|
||
|
||
This filter is also designed to efficiently remap the channels of an audio
|
||
stream.
|
||
|
||
The filter accepts parameters of the form:
|
||
"@var{l}|@var{outdef}|@var{outdef}|..."
|
||
|
||
@table @option
|
||
@item l
|
||
output channel layout or number of channels
|
||
|
||
@item outdef
|
||
output channel specification, of the form:
|
||
"@var{out_name}=[@var{gain}*]@var{in_name}[(+-)[@var{gain}*]@var{in_name}...]"
|
||
|
||
@item out_name
|
||
output channel to define, either a channel name (FL, FR, etc.) or a channel
|
||
number (c0, c1, etc.)
|
||
|
||
@item gain
|
||
multiplicative coefficient for the channel, 1 leaving the volume unchanged
|
||
|
||
@item in_name
|
||
input channel to use, see out_name for details; it is not possible to mix
|
||
named and numbered input channels
|
||
@end table
|
||
|
||
If the `=' in a channel specification is replaced by `<', then the gains for
|
||
that specification will be renormalized so that the total is 1, thus
|
||
avoiding clipping noise.
|
||
|
||
@subsection Mixing examples
|
||
|
||
For example, if you want to down-mix from stereo to mono, but with a bigger
|
||
factor for the left channel:
|
||
@example
|
||
pan=1c|c0=0.9*c0+0.1*c1
|
||
@end example
|
||
|
||
A customized down-mix to stereo that works automatically for 3-, 4-, 5- and
|
||
7-channels surround:
|
||
@example
|
||
pan=stereo| FL < FL + 0.5*FC + 0.6*BL + 0.6*SL | FR < FR + 0.5*FC + 0.6*BR + 0.6*SR
|
||
@end example
|
||
|
||
Note that @command{ffmpeg} integrates a default down-mix (and up-mix) system
|
||
that should be preferred (see "-ac" option) unless you have very specific
|
||
needs.
|
||
|
||
@subsection Remapping examples
|
||
|
||
The channel remapping will be effective if, and only if:
|
||
|
||
@itemize
|
||
@item gain coefficients are zeroes or ones,
|
||
@item only one input per channel output,
|
||
@end itemize
|
||
|
||
If all these conditions are satisfied, the filter will notify the user ("Pure
|
||
channel mapping detected"), and use an optimized and lossless method to do the
|
||
remapping.
|
||
|
||
For example, if you have a 5.1 source and want a stereo audio stream by
|
||
dropping the extra channels:
|
||
@example
|
||
pan="stereo| c0=FL | c1=FR"
|
||
@end example
|
||
|
||
Given the same source, you can also switch front left and front right channels
|
||
and keep the input channel layout:
|
||
@example
|
||
pan="5.1| c0=c1 | c1=c0 | c2=c2 | c3=c3 | c4=c4 | c5=c5"
|
||
@end example
|
||
|
||
If the input is a stereo audio stream, you can mute the front left channel (and
|
||
still keep the stereo channel layout) with:
|
||
@example
|
||
pan="stereo|c1=c1"
|
||
@end example
|
||
|
||
Still with a stereo audio stream input, you can copy the right channel in both
|
||
front left and right:
|
||
@example
|
||
pan="stereo| c0=FR | c1=FR"
|
||
@end example
|
||
|
||
@section replaygain
|
||
|
||
ReplayGain scanner filter. This filter takes an audio stream as an input and
|
||
outputs it unchanged.
|
||
At end of filtering it displays @code{track_gain} and @code{track_peak}.
|
||
|
||
@section resample
|
||
|
||
Convert the audio sample format, sample rate and channel layout. It is
|
||
not meant to be used directly.
|
||
|
||
@section rubberband
|
||
Apply time-stretching and pitch-shifting with librubberband.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item tempo
|
||
Set tempo scale factor.
|
||
|
||
@item pitch
|
||
Set pitch scale factor.
|
||
|
||
@item transients
|
||
Set transients detector.
|
||
Possible values are:
|
||
@table @var
|
||
@item crisp
|
||
@item mixed
|
||
@item smooth
|
||
@end table
|
||
|
||
@item detector
|
||
Set detector.
|
||
Possible values are:
|
||
@table @var
|
||
@item compound
|
||
@item percussive
|
||
@item soft
|
||
@end table
|
||
|
||
@item phase
|
||
Set phase.
|
||
Possible values are:
|
||
@table @var
|
||
@item laminar
|
||
@item independent
|
||
@end table
|
||
|
||
@item window
|
||
Set processing window size.
|
||
Possible values are:
|
||
@table @var
|
||
@item standard
|
||
@item short
|
||
@item long
|
||
@end table
|
||
|
||
@item smoothing
|
||
Set smoothing.
|
||
Possible values are:
|
||
@table @var
|
||
@item off
|
||
@item on
|
||
@end table
|
||
|
||
@item formant
|
||
Enable formant preservation when shift pitching.
|
||
Possible values are:
|
||
@table @var
|
||
@item shifted
|
||
@item preserved
|
||
@end table
|
||
|
||
@item pitchq
|
||
Set pitch quality.
|
||
Possible values are:
|
||
@table @var
|
||
@item quality
|
||
@item speed
|
||
@item consistency
|
||
@end table
|
||
|
||
@item channels
|
||
Set channels.
|
||
Possible values are:
|
||
@table @var
|
||
@item apart
|
||
@item together
|
||
@end table
|
||
@end table
|
||
|
||
@section sidechaincompress
|
||
|
||
This filter acts like normal compressor but has the ability to compress
|
||
detected signal using second input signal.
|
||
It needs two input streams and returns one output stream.
|
||
First input stream will be processed depending on second stream signal.
|
||
The filtered signal then can be filtered with other filters in later stages of
|
||
processing. See @ref{pan} and @ref{amerge} filter.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item level_in
|
||
Set input gain. Default is 1. Range is between 0.015625 and 64.
|
||
|
||
@item threshold
|
||
If a signal of second stream raises above this level it will affect the gain
|
||
reduction of first stream.
|
||
By default is 0.125. Range is between 0.00097563 and 1.
|
||
|
||
@item ratio
|
||
Set a ratio about which the signal is reduced. 1:2 means that if the level
|
||
raised 4dB above the threshold, it will be only 2dB above after the reduction.
|
||
Default is 2. Range is between 1 and 20.
|
||
|
||
@item attack
|
||
Amount of milliseconds the signal has to rise above the threshold before gain
|
||
reduction starts. Default is 20. Range is between 0.01 and 2000.
|
||
|
||
@item release
|
||
Amount of milliseconds the signal has to fall below the threshold before
|
||
reduction is decreased again. Default is 250. Range is between 0.01 and 9000.
|
||
|
||
@item makeup
|
||
Set the amount by how much signal will be amplified after processing.
|
||
Default is 1. Range is from 1 to 64.
|
||
|
||
@item knee
|
||
Curve the sharp knee around the threshold to enter gain reduction more softly.
|
||
Default is 2.82843. Range is between 1 and 8.
|
||
|
||
@item link
|
||
Choose if the @code{average} level between all channels of side-chain stream
|
||
or the louder(@code{maximum}) channel of side-chain stream affects the
|
||
reduction. Default is @code{average}.
|
||
|
||
@item detection
|
||
Should the exact signal be taken in case of @code{peak} or an RMS one in case
|
||
of @code{rms}. Default is @code{rms} which is mainly smoother.
|
||
|
||
@item level_sc
|
||
Set sidechain gain. Default is 1. Range is between 0.015625 and 64.
|
||
|
||
@item mix
|
||
How much to use compressed signal in output. Default is 1.
|
||
Range is between 0 and 1.
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Full ffmpeg example taking 2 audio inputs, 1st input to be compressed
|
||
depending on the signal of 2nd input and later compressed signal to be
|
||
merged with 2nd input:
|
||
@example
|
||
ffmpeg -i main.flac -i sidechain.flac -filter_complex "[1:a]asplit=2[sc][mix];[0:a][sc]sidechaincompress[compr];[compr][mix]amerge"
|
||
@end example
|
||
@end itemize
|
||
|
||
@section sidechaingate
|
||
|
||
A sidechain gate acts like a normal (wideband) gate but has the ability to
|
||
filter the detected signal before sending it to the gain reduction stage.
|
||
Normally a gate uses the full range signal to detect a level above the
|
||
threshold.
|
||
For example: If you cut all lower frequencies from your sidechain signal
|
||
the gate will decrease the volume of your track only if not enough highs
|
||
appear. With this technique you are able to reduce the resonation of a
|
||
natural drum or remove "rumbling" of muted strokes from a heavily distorted
|
||
guitar.
|
||
It needs two input streams and returns one output stream.
|
||
First input stream will be processed depending on second stream signal.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item level_in
|
||
Set input level before filtering.
|
||
Default is 1. Allowed range is from 0.015625 to 64.
|
||
|
||
@item range
|
||
Set the level of gain reduction when the signal is below the threshold.
|
||
Default is 0.06125. Allowed range is from 0 to 1.
|
||
|
||
@item threshold
|
||
If a signal rises above this level the gain reduction is released.
|
||
Default is 0.125. Allowed range is from 0 to 1.
|
||
|
||
@item ratio
|
||
Set a ratio about which the signal is reduced.
|
||
Default is 2. Allowed range is from 1 to 9000.
|
||
|
||
@item attack
|
||
Amount of milliseconds the signal has to rise above the threshold before gain
|
||
reduction stops.
|
||
Default is 20 milliseconds. Allowed range is from 0.01 to 9000.
|
||
|
||
@item release
|
||
Amount of milliseconds the signal has to fall below the threshold before the
|
||
reduction is increased again. Default is 250 milliseconds.
|
||
Allowed range is from 0.01 to 9000.
|
||
|
||
@item makeup
|
||
Set amount of amplification of signal after processing.
|
||
Default is 1. Allowed range is from 1 to 64.
|
||
|
||
@item knee
|
||
Curve the sharp knee around the threshold to enter gain reduction more softly.
|
||
Default is 2.828427125. Allowed range is from 1 to 8.
|
||
|
||
@item detection
|
||
Choose if exact signal should be taken for detection or an RMS like one.
|
||
Default is rms. Can be peak or rms.
|
||
|
||
@item link
|
||
Choose if the average level between all channels or the louder channel affects
|
||
the reduction.
|
||
Default is average. Can be average or maximum.
|
||
|
||
@item level_sc
|
||
Set sidechain gain. Default is 1. Range is from 0.015625 to 64.
|
||
@end table
|
||
|
||
@section silencedetect
|
||
|
||
Detect silence in an audio stream.
|
||
|
||
This filter logs a message when it detects that the input audio volume is less
|
||
or equal to a noise tolerance value for a duration greater or equal to the
|
||
minimum detected noise duration.
|
||
|
||
The printed times and duration are expressed in seconds.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item duration, d
|
||
Set silence duration until notification (default is 2 seconds).
|
||
|
||
@item noise, n
|
||
Set noise tolerance. Can be specified in dB (in case "dB" is appended to the
|
||
specified value) or amplitude ratio. Default is -60dB, or 0.001.
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Detect 5 seconds of silence with -50dB noise tolerance:
|
||
@example
|
||
silencedetect=n=-50dB:d=5
|
||
@end example
|
||
|
||
@item
|
||
Complete example with @command{ffmpeg} to detect silence with 0.0001 noise
|
||
tolerance in @file{silence.mp3}:
|
||
@example
|
||
ffmpeg -i silence.mp3 -af silencedetect=noise=0.0001 -f null -
|
||
@end example
|
||
@end itemize
|
||
|
||
@section silenceremove
|
||
|
||
Remove silence from the beginning, middle or end of the audio.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item start_periods
|
||
This value is used to indicate if audio should be trimmed at beginning of
|
||
the audio. A value of zero indicates no silence should be trimmed from the
|
||
beginning. When specifying a non-zero value, it trims audio up until it
|
||
finds non-silence. Normally, when trimming silence from beginning of audio
|
||
the @var{start_periods} will be @code{1} but it can be increased to higher
|
||
values to trim all audio up to specific count of non-silence periods.
|
||
Default value is @code{0}.
|
||
|
||
@item start_duration
|
||
Specify the amount of time that non-silence must be detected before it stops
|
||
trimming audio. By increasing the duration, bursts of noises can be treated
|
||
as silence and trimmed off. Default value is @code{0}.
|
||
|
||
@item start_threshold
|
||
This indicates what sample value should be treated as silence. For digital
|
||
audio, a value of @code{0} may be fine but for audio recorded from analog,
|
||
you may wish to increase the value to account for background noise.
|
||
Can be specified in dB (in case "dB" is appended to the specified value)
|
||
or amplitude ratio. Default value is @code{0}.
|
||
|
||
@item stop_periods
|
||
Set the count for trimming silence from the end of audio.
|
||
To remove silence from the middle of a file, specify a @var{stop_periods}
|
||
that is negative. This value is then treated as a positive value and is
|
||
used to indicate the effect should restart processing as specified by
|
||
@var{start_periods}, making it suitable for removing periods of silence
|
||
in the middle of the audio.
|
||
Default value is @code{0}.
|
||
|
||
@item stop_duration
|
||
Specify a duration of silence that must exist before audio is not copied any
|
||
more. By specifying a higher duration, silence that is wanted can be left in
|
||
the audio.
|
||
Default value is @code{0}.
|
||
|
||
@item stop_threshold
|
||
This is the same as @option{start_threshold} but for trimming silence from
|
||
the end of audio.
|
||
Can be specified in dB (in case "dB" is appended to the specified value)
|
||
or amplitude ratio. Default value is @code{0}.
|
||
|
||
@item leave_silence
|
||
This indicates that @var{stop_duration} length of audio should be left intact
|
||
at the beginning of each period of silence.
|
||
For example, if you want to remove long pauses between words but do not want
|
||
to remove the pauses completely. Default value is @code{0}.
|
||
|
||
@item detection
|
||
Set how is silence detected. Can be @code{rms} or @code{peak}. Second is faster
|
||
and works better with digital silence which is exactly 0.
|
||
Default value is @code{rms}.
|
||
|
||
@item window
|
||
Set ratio used to calculate size of window for detecting silence.
|
||
Default value is @code{0.02}. Allowed range is from @code{0} to @code{10}.
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
The following example shows how this filter can be used to start a recording
|
||
that does not contain the delay at the start which usually occurs between
|
||
pressing the record button and the start of the performance:
|
||
@example
|
||
silenceremove=1:5:0.02
|
||
@end example
|
||
|
||
@item
|
||
Trim all silence encountered from beginning to end where there is more than 1
|
||
second of silence in audio:
|
||
@example
|
||
silenceremove=0:0:0:-1:1:-90dB
|
||
@end example
|
||
@end itemize
|
||
|
||
@section sofalizer
|
||
|
||
SOFAlizer uses head-related transfer functions (HRTFs) to create virtual
|
||
loudspeakers around the user for binaural listening via headphones (audio
|
||
formats up to 9 channels supported).
|
||
The HRTFs are stored in SOFA files (see @url{http://www.sofacoustics.org/} for a database).
|
||
SOFAlizer is developed at the Acoustics Research Institute (ARI) of the
|
||
Austrian Academy of Sciences.
|
||
|
||
To enable compilation of this filter you need to configure FFmpeg with
|
||
@code{--enable-libmysofa}.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item sofa
|
||
Set the SOFA file used for rendering.
|
||
|
||
@item gain
|
||
Set gain applied to audio. Value is in dB. Default is 0.
|
||
|
||
@item rotation
|
||
Set rotation of virtual loudspeakers in deg. Default is 0.
|
||
|
||
@item elevation
|
||
Set elevation of virtual speakers in deg. Default is 0.
|
||
|
||
@item radius
|
||
Set distance in meters between loudspeakers and the listener with near-field
|
||
HRTFs. Default is 1.
|
||
|
||
@item type
|
||
Set processing type. Can be @var{time} or @var{freq}. @var{time} is
|
||
processing audio in time domain which is slow.
|
||
@var{freq} is processing audio in frequency domain which is fast.
|
||
Default is @var{freq}.
|
||
|
||
@item speakers
|
||
Set custom positions of virtual loudspeakers. Syntax for this option is:
|
||
<CH> <AZIM> <ELEV>[|<CH> <AZIM> <ELEV>|...].
|
||
Each virtual loudspeaker is described with short channel name following with
|
||
azimuth and elevation in degreees.
|
||
Each virtual loudspeaker description is separated by '|'.
|
||
For example to override front left and front right channel positions use:
|
||
'speakers=FL 45 15|FR 345 15'.
|
||
Descriptions with unrecognised channel names are ignored.
|
||
|
||
@item lfegain
|
||
Set custom gain for LFE channels. Value is in dB. Default is 0.
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Using ClubFritz6 sofa file:
|
||
@example
|
||
sofalizer=sofa=/path/to/ClubFritz6.sofa:type=freq:radius=1
|
||
@end example
|
||
|
||
@item
|
||
Using ClubFritz12 sofa file and bigger radius with small rotation:
|
||
@example
|
||
sofalizer=sofa=/path/to/ClubFritz12.sofa:type=freq:radius=2:rotation=5
|
||
@end example
|
||
|
||
@item
|
||
Similar as above but with custom speaker positions for front left, front right, back left and back right
|
||
and also with custom gain:
|
||
@example
|
||
"sofalizer=sofa=/path/to/ClubFritz6.sofa:type=freq:radius=2:speakers=FL 45|FR 315|BL 135|BR 225:gain=28"
|
||
@end example
|
||
@end itemize
|
||
|
||
@section stereotools
|
||
|
||
This filter has some handy utilities to manage stereo signals, for converting
|
||
M/S stereo recordings to L/R signal while having control over the parameters
|
||
or spreading the stereo image of master track.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item level_in
|
||
Set input level before filtering for both channels. Defaults is 1.
|
||
Allowed range is from 0.015625 to 64.
|
||
|
||
@item level_out
|
||
Set output level after filtering for both channels. Defaults is 1.
|
||
Allowed range is from 0.015625 to 64.
|
||
|
||
@item balance_in
|
||
Set input balance between both channels. Default is 0.
|
||
Allowed range is from -1 to 1.
|
||
|
||
@item balance_out
|
||
Set output balance between both channels. Default is 0.
|
||
Allowed range is from -1 to 1.
|
||
|
||
@item softclip
|
||
Enable softclipping. Results in analog distortion instead of harsh digital 0dB
|
||
clipping. Disabled by default.
|
||
|
||
@item mutel
|
||
Mute the left channel. Disabled by default.
|
||
|
||
@item muter
|
||
Mute the right channel. Disabled by default.
|
||
|
||
@item phasel
|
||
Change the phase of the left channel. Disabled by default.
|
||
|
||
@item phaser
|
||
Change the phase of the right channel. Disabled by default.
|
||
|
||
@item mode
|
||
Set stereo mode. Available values are:
|
||
|
||
@table @samp
|
||
@item lr>lr
|
||
Left/Right to Left/Right, this is default.
|
||
|
||
@item lr>ms
|
||
Left/Right to Mid/Side.
|
||
|
||
@item ms>lr
|
||
Mid/Side to Left/Right.
|
||
|
||
@item lr>ll
|
||
Left/Right to Left/Left.
|
||
|
||
@item lr>rr
|
||
Left/Right to Right/Right.
|
||
|
||
@item lr>l+r
|
||
Left/Right to Left + Right.
|
||
|
||
@item lr>rl
|
||
Left/Right to Right/Left.
|
||
|
||
@item ms>ll
|
||
Mid/Side to Left/Left.
|
||
|
||
@item ms>rr
|
||
Mid/Side to Right/Right.
|
||
@end table
|
||
|
||
@item slev
|
||
Set level of side signal. Default is 1.
|
||
Allowed range is from 0.015625 to 64.
|
||
|
||
@item sbal
|
||
Set balance of side signal. Default is 0.
|
||
Allowed range is from -1 to 1.
|
||
|
||
@item mlev
|
||
Set level of the middle signal. Default is 1.
|
||
Allowed range is from 0.015625 to 64.
|
||
|
||
@item mpan
|
||
Set middle signal pan. Default is 0. Allowed range is from -1 to 1.
|
||
|
||
@item base
|
||
Set stereo base between mono and inversed channels. Default is 0.
|
||
Allowed range is from -1 to 1.
|
||
|
||
@item delay
|
||
Set delay in milliseconds how much to delay left from right channel and
|
||
vice versa. Default is 0. Allowed range is from -20 to 20.
|
||
|
||
@item sclevel
|
||
Set S/C level. Default is 1. Allowed range is from 1 to 100.
|
||
|
||
@item phase
|
||
Set the stereo phase in degrees. Default is 0. Allowed range is from 0 to 360.
|
||
|
||
@item bmode_in, bmode_out
|
||
Set balance mode for balance_in/balance_out option.
|
||
|
||
Can be one of the following:
|
||
|
||
@table @samp
|
||
@item balance
|
||
Classic balance mode. Attenuate one channel at time.
|
||
Gain is raised up to 1.
|
||
|
||
@item amplitude
|
||
Similar as classic mode above but gain is raised up to 2.
|
||
|
||
@item power
|
||
Equal power distribution, from -6dB to +6dB range.
|
||
@end table
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Apply karaoke like effect:
|
||
@example
|
||
stereotools=mlev=0.015625
|
||
@end example
|
||
|
||
@item
|
||
Convert M/S signal to L/R:
|
||
@example
|
||
"stereotools=mode=ms>lr"
|
||
@end example
|
||
@end itemize
|
||
|
||
@section stereowiden
|
||
|
||
This filter enhance the stereo effect by suppressing signal common to both
|
||
channels and by delaying the signal of left into right and vice versa,
|
||
thereby widening the stereo effect.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item delay
|
||
Time in milliseconds of the delay of left signal into right and vice versa.
|
||
Default is 20 milliseconds.
|
||
|
||
@item feedback
|
||
Amount of gain in delayed signal into right and vice versa. Gives a delay
|
||
effect of left signal in right output and vice versa which gives widening
|
||
effect. Default is 0.3.
|
||
|
||
@item crossfeed
|
||
Cross feed of left into right with inverted phase. This helps in suppressing
|
||
the mono. If the value is 1 it will cancel all the signal common to both
|
||
channels. Default is 0.3.
|
||
|
||
@item drymix
|
||
Set level of input signal of original channel. Default is 0.8.
|
||
@end table
|
||
|
||
@section superequalizer
|
||
Apply 18 band equalizer.
|
||
|
||
The filter accepts the following options:
|
||
@table @option
|
||
@item 1b
|
||
Set 65Hz band gain.
|
||
@item 2b
|
||
Set 92Hz band gain.
|
||
@item 3b
|
||
Set 131Hz band gain.
|
||
@item 4b
|
||
Set 185Hz band gain.
|
||
@item 5b
|
||
Set 262Hz band gain.
|
||
@item 6b
|
||
Set 370Hz band gain.
|
||
@item 7b
|
||
Set 523Hz band gain.
|
||
@item 8b
|
||
Set 740Hz band gain.
|
||
@item 9b
|
||
Set 1047Hz band gain.
|
||
@item 10b
|
||
Set 1480Hz band gain.
|
||
@item 11b
|
||
Set 2093Hz band gain.
|
||
@item 12b
|
||
Set 2960Hz band gain.
|
||
@item 13b
|
||
Set 4186Hz band gain.
|
||
@item 14b
|
||
Set 5920Hz band gain.
|
||
@item 15b
|
||
Set 8372Hz band gain.
|
||
@item 16b
|
||
Set 11840Hz band gain.
|
||
@item 17b
|
||
Set 16744Hz band gain.
|
||
@item 18b
|
||
Set 20000Hz band gain.
|
||
@end table
|
||
|
||
@section surround
|
||
Apply audio surround upmix filter.
|
||
|
||
This filter allows to produce multichannel output from audio stream.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item chl_out
|
||
Set output channel layout. By default, this is @var{5.1}.
|
||
|
||
See @ref{channel layout syntax,,the Channel Layout section in the ffmpeg-utils(1) manual,ffmpeg-utils}
|
||
for the required syntax.
|
||
|
||
@item chl_in
|
||
Set input channel layout. By default, this is @var{stereo}.
|
||
|
||
See @ref{channel layout syntax,,the Channel Layout section in the ffmpeg-utils(1) manual,ffmpeg-utils}
|
||
for the required syntax.
|
||
|
||
@item level_in
|
||
Set input volume level. By default, this is @var{1}.
|
||
|
||
@item level_out
|
||
Set output volume level. By default, this is @var{1}.
|
||
|
||
@item lfe
|
||
Enable LFE channel output if output channel layout has it. By default, this is enabled.
|
||
|
||
@item lfe_low
|
||
Set LFE low cut off frequency. By default, this is @var{128} Hz.
|
||
|
||
@item lfe_high
|
||
Set LFE high cut off frequency. By default, this is @var{256} Hz.
|
||
@end table
|
||
|
||
@section treble
|
||
|
||
Boost or cut treble (upper) frequencies of the audio using a two-pole
|
||
shelving filter with a response similar to that of a standard
|
||
hi-fi's tone-controls. This is also known as shelving equalisation (EQ).
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item gain, g
|
||
Give the gain at whichever is the lower of ~22 kHz and the
|
||
Nyquist frequency. Its useful range is about -20 (for a large cut)
|
||
to +20 (for a large boost). Beware of clipping when using a positive gain.
|
||
|
||
@item frequency, f
|
||
Set the filter's central frequency and so can be used
|
||
to extend or reduce the frequency range to be boosted or cut.
|
||
The default value is @code{3000} Hz.
|
||
|
||
@item width_type, t
|
||
Set method to specify band-width of filter.
|
||
@table @option
|
||
@item h
|
||
Hz
|
||
@item q
|
||
Q-Factor
|
||
@item o
|
||
octave
|
||
@item s
|
||
slope
|
||
@end table
|
||
|
||
@item width, w
|
||
Determine how steep is the filter's shelf transition.
|
||
|
||
@item channels, c
|
||
Specify which channels to filter, by default all available are filtered.
|
||
@end table
|
||
|
||
@section tremolo
|
||
|
||
Sinusoidal amplitude modulation.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item f
|
||
Modulation frequency in Hertz. Modulation frequencies in the subharmonic range
|
||
(20 Hz or lower) will result in a tremolo effect.
|
||
This filter may also be used as a ring modulator by specifying
|
||
a modulation frequency higher than 20 Hz.
|
||
Range is 0.1 - 20000.0. Default value is 5.0 Hz.
|
||
|
||
@item d
|
||
Depth of modulation as a percentage. Range is 0.0 - 1.0.
|
||
Default value is 0.5.
|
||
@end table
|
||
|
||
@section vibrato
|
||
|
||
Sinusoidal phase modulation.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item f
|
||
Modulation frequency in Hertz.
|
||
Range is 0.1 - 20000.0. Default value is 5.0 Hz.
|
||
|
||
@item d
|
||
Depth of modulation as a percentage. Range is 0.0 - 1.0.
|
||
Default value is 0.5.
|
||
@end table
|
||
|
||
@section volume
|
||
|
||
Adjust the input audio volume.
|
||
|
||
It accepts the following parameters:
|
||
@table @option
|
||
|
||
@item volume
|
||
Set audio volume expression.
|
||
|
||
Output values are clipped to the maximum value.
|
||
|
||
The output audio volume is given by the relation:
|
||
@example
|
||
@var{output_volume} = @var{volume} * @var{input_volume}
|
||
@end example
|
||
|
||
The default value for @var{volume} is "1.0".
|
||
|
||
@item precision
|
||
This parameter represents the mathematical precision.
|
||
|
||
It determines which input sample formats will be allowed, which affects the
|
||
precision of the volume scaling.
|
||
|
||
@table @option
|
||
@item fixed
|
||
8-bit fixed-point; this limits input sample format to U8, S16, and S32.
|
||
@item float
|
||
32-bit floating-point; this limits input sample format to FLT. (default)
|
||
@item double
|
||
64-bit floating-point; this limits input sample format to DBL.
|
||
@end table
|
||
|
||
@item replaygain
|
||
Choose the behaviour on encountering ReplayGain side data in input frames.
|
||
|
||
@table @option
|
||
@item drop
|
||
Remove ReplayGain side data, ignoring its contents (the default).
|
||
|
||
@item ignore
|
||
Ignore ReplayGain side data, but leave it in the frame.
|
||
|
||
@item track
|
||
Prefer the track gain, if present.
|
||
|
||
@item album
|
||
Prefer the album gain, if present.
|
||
@end table
|
||
|
||
@item replaygain_preamp
|
||
Pre-amplification gain in dB to apply to the selected replaygain gain.
|
||
|
||
Default value for @var{replaygain_preamp} is 0.0.
|
||
|
||
@item eval
|
||
Set when the volume expression is evaluated.
|
||
|
||
It accepts the following values:
|
||
@table @samp
|
||
@item once
|
||
only evaluate expression once during the filter initialization, or
|
||
when the @samp{volume} command is sent
|
||
|
||
@item frame
|
||
evaluate expression for each incoming frame
|
||
@end table
|
||
|
||
Default value is @samp{once}.
|
||
@end table
|
||
|
||
The volume expression can contain the following parameters.
|
||
|
||
@table @option
|
||
@item n
|
||
frame number (starting at zero)
|
||
@item nb_channels
|
||
number of channels
|
||
@item nb_consumed_samples
|
||
number of samples consumed by the filter
|
||
@item nb_samples
|
||
number of samples in the current frame
|
||
@item pos
|
||
original frame position in the file
|
||
@item pts
|
||
frame PTS
|
||
@item sample_rate
|
||
sample rate
|
||
@item startpts
|
||
PTS at start of stream
|
||
@item startt
|
||
time at start of stream
|
||
@item t
|
||
frame time
|
||
@item tb
|
||
timestamp timebase
|
||
@item volume
|
||
last set volume value
|
||
@end table
|
||
|
||
Note that when @option{eval} is set to @samp{once} only the
|
||
@var{sample_rate} and @var{tb} variables are available, all other
|
||
variables will evaluate to NAN.
|
||
|
||
@subsection Commands
|
||
|
||
This filter supports the following commands:
|
||
@table @option
|
||
@item volume
|
||
Modify the volume expression.
|
||
The command accepts the same syntax of the corresponding option.
|
||
|
||
If the specified expression is not valid, it is kept at its current
|
||
value.
|
||
@item replaygain_noclip
|
||
Prevent clipping by limiting the gain applied.
|
||
|
||
Default value for @var{replaygain_noclip} is 1.
|
||
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Halve the input audio volume:
|
||
@example
|
||
volume=volume=0.5
|
||
volume=volume=1/2
|
||
volume=volume=-6.0206dB
|
||
@end example
|
||
|
||
In all the above example the named key for @option{volume} can be
|
||
omitted, for example like in:
|
||
@example
|
||
volume=0.5
|
||
@end example
|
||
|
||
@item
|
||
Increase input audio power by 6 decibels using fixed-point precision:
|
||
@example
|
||
volume=volume=6dB:precision=fixed
|
||
@end example
|
||
|
||
@item
|
||
Fade volume after time 10 with an annihilation period of 5 seconds:
|
||
@example
|
||
volume='if(lt(t,10),1,max(1-(t-10)/5,0))':eval=frame
|
||
@end example
|
||
@end itemize
|
||
|
||
@section volumedetect
|
||
|
||
Detect the volume of the input video.
|
||
|
||
The filter has no parameters. The input is not modified. Statistics about
|
||
the volume will be printed in the log when the input stream end is reached.
|
||
|
||
In particular it will show the mean volume (root mean square), maximum
|
||
volume (on a per-sample basis), and the beginning of a histogram of the
|
||
registered volume values (from the maximum value to a cumulated 1/1000 of
|
||
the samples).
|
||
|
||
All volumes are in decibels relative to the maximum PCM value.
|
||
|
||
@subsection Examples
|
||
|
||
Here is an excerpt of the output:
|
||
@example
|
||
[Parsed_volumedetect_0 @ 0xa23120] mean_volume: -27 dB
|
||
[Parsed_volumedetect_0 @ 0xa23120] max_volume: -4 dB
|
||
[Parsed_volumedetect_0 @ 0xa23120] histogram_4db: 6
|
||
[Parsed_volumedetect_0 @ 0xa23120] histogram_5db: 62
|
||
[Parsed_volumedetect_0 @ 0xa23120] histogram_6db: 286
|
||
[Parsed_volumedetect_0 @ 0xa23120] histogram_7db: 1042
|
||
[Parsed_volumedetect_0 @ 0xa23120] histogram_8db: 2551
|
||
[Parsed_volumedetect_0 @ 0xa23120] histogram_9db: 4609
|
||
[Parsed_volumedetect_0 @ 0xa23120] histogram_10db: 8409
|
||
@end example
|
||
|
||
It means that:
|
||
@itemize
|
||
@item
|
||
The mean square energy is approximately -27 dB, or 10^-2.7.
|
||
@item
|
||
The largest sample is at -4 dB, or more precisely between -4 dB and -5 dB.
|
||
@item
|
||
There are 6 samples at -4 dB, 62 at -5 dB, 286 at -6 dB, etc.
|
||
@end itemize
|
||
|
||
In other words, raising the volume by +4 dB does not cause any clipping,
|
||
raising it by +5 dB causes clipping for 6 samples, etc.
|
||
|
||
@c man end AUDIO FILTERS
|
||
|
||
@chapter Audio Sources
|
||
@c man begin AUDIO SOURCES
|
||
|
||
Below is a description of the currently available audio sources.
|
||
|
||
@section abuffer
|
||
|
||
Buffer audio frames, and make them available to the filter chain.
|
||
|
||
This source is mainly intended for a programmatic use, in particular
|
||
through the interface defined in @file{libavfilter/asrc_abuffer.h}.
|
||
|
||
It accepts the following parameters:
|
||
@table @option
|
||
|
||
@item time_base
|
||
The timebase which will be used for timestamps of submitted frames. It must be
|
||
either a floating-point number or in @var{numerator}/@var{denominator} form.
|
||
|
||
@item sample_rate
|
||
The sample rate of the incoming audio buffers.
|
||
|
||
@item sample_fmt
|
||
The sample format of the incoming audio buffers.
|
||
Either a sample format name or its corresponding integer representation from
|
||
the enum AVSampleFormat in @file{libavutil/samplefmt.h}
|
||
|
||
@item channel_layout
|
||
The channel layout of the incoming audio buffers.
|
||
Either a channel layout name from channel_layout_map in
|
||
@file{libavutil/channel_layout.c} or its corresponding integer representation
|
||
from the AV_CH_LAYOUT_* macros in @file{libavutil/channel_layout.h}
|
||
|
||
@item channels
|
||
The number of channels of the incoming audio buffers.
|
||
If both @var{channels} and @var{channel_layout} are specified, then they
|
||
must be consistent.
|
||
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@example
|
||
abuffer=sample_rate=44100:sample_fmt=s16p:channel_layout=stereo
|
||
@end example
|
||
|
||
will instruct the source to accept planar 16bit signed stereo at 44100Hz.
|
||
Since the sample format with name "s16p" corresponds to the number
|
||
6 and the "stereo" channel layout corresponds to the value 0x3, this is
|
||
equivalent to:
|
||
@example
|
||
abuffer=sample_rate=44100:sample_fmt=6:channel_layout=0x3
|
||
@end example
|
||
|
||
@section aevalsrc
|
||
|
||
Generate an audio signal specified by an expression.
|
||
|
||
This source accepts in input one or more expressions (one for each
|
||
channel), which are evaluated and used to generate a corresponding
|
||
audio signal.
|
||
|
||
This source accepts the following options:
|
||
|
||
@table @option
|
||
@item exprs
|
||
Set the '|'-separated expressions list for each separate channel. In case the
|
||
@option{channel_layout} option is not specified, the selected channel layout
|
||
depends on the number of provided expressions. Otherwise the last
|
||
specified expression is applied to the remaining output channels.
|
||
|
||
@item channel_layout, c
|
||
Set the channel layout. The number of channels in the specified layout
|
||
must be equal to the number of specified expressions.
|
||
|
||
@item duration, d
|
||
Set the minimum duration of the sourced audio. See
|
||
@ref{time duration syntax,,the Time duration section in the ffmpeg-utils(1) manual,ffmpeg-utils}
|
||
for the accepted syntax.
|
||
Note that the resulting duration may be greater than the specified
|
||
duration, as the generated audio is always cut at the end of a
|
||
complete frame.
|
||
|
||
If not specified, or the expressed duration is negative, the audio is
|
||
supposed to be generated forever.
|
||
|
||
@item nb_samples, n
|
||
Set the number of samples per channel per each output frame,
|
||
default to 1024.
|
||
|
||
@item sample_rate, s
|
||
Specify the sample rate, default to 44100.
|
||
@end table
|
||
|
||
Each expression in @var{exprs} can contain the following constants:
|
||
|
||
@table @option
|
||
@item n
|
||
number of the evaluated sample, starting from 0
|
||
|
||
@item t
|
||
time of the evaluated sample expressed in seconds, starting from 0
|
||
|
||
@item s
|
||
sample rate
|
||
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Generate silence:
|
||
@example
|
||
aevalsrc=0
|
||
@end example
|
||
|
||
@item
|
||
Generate a sin signal with frequency of 440 Hz, set sample rate to
|
||
8000 Hz:
|
||
@example
|
||
aevalsrc="sin(440*2*PI*t):s=8000"
|
||
@end example
|
||
|
||
@item
|
||
Generate a two channels signal, specify the channel layout (Front
|
||
Center + Back Center) explicitly:
|
||
@example
|
||
aevalsrc="sin(420*2*PI*t)|cos(430*2*PI*t):c=FC|BC"
|
||
@end example
|
||
|
||
@item
|
||
Generate white noise:
|
||
@example
|
||
aevalsrc="-2+random(0)"
|
||
@end example
|
||
|
||
@item
|
||
Generate an amplitude modulated signal:
|
||
@example
|
||
aevalsrc="sin(10*2*PI*t)*sin(880*2*PI*t)"
|
||
@end example
|
||
|
||
@item
|
||
Generate 2.5 Hz binaural beats on a 360 Hz carrier:
|
||
@example
|
||
aevalsrc="0.1*sin(2*PI*(360-2.5/2)*t) | 0.1*sin(2*PI*(360+2.5/2)*t)"
|
||
@end example
|
||
|
||
@end itemize
|
||
|
||
@section anullsrc
|
||
|
||
The null audio source, return unprocessed audio frames. It is mainly useful
|
||
as a template and to be employed in analysis / debugging tools, or as
|
||
the source for filters which ignore the input data (for example the sox
|
||
synth filter).
|
||
|
||
This source accepts the following options:
|
||
|
||
@table @option
|
||
|
||
@item channel_layout, cl
|
||
|
||
Specifies the channel layout, and can be either an integer or a string
|
||
representing a channel layout. The default value of @var{channel_layout}
|
||
is "stereo".
|
||
|
||
Check the channel_layout_map definition in
|
||
@file{libavutil/channel_layout.c} for the mapping between strings and
|
||
channel layout values.
|
||
|
||
@item sample_rate, r
|
||
Specifies the sample rate, and defaults to 44100.
|
||
|
||
@item nb_samples, n
|
||
Set the number of samples per requested frames.
|
||
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Set the sample rate to 48000 Hz and the channel layout to AV_CH_LAYOUT_MONO.
|
||
@example
|
||
anullsrc=r=48000:cl=4
|
||
@end example
|
||
|
||
@item
|
||
Do the same operation with a more obvious syntax:
|
||
@example
|
||
anullsrc=r=48000:cl=mono
|
||
@end example
|
||
@end itemize
|
||
|
||
All the parameters need to be explicitly defined.
|
||
|
||
@section flite
|
||
|
||
Synthesize a voice utterance using the libflite library.
|
||
|
||
To enable compilation of this filter you need to configure FFmpeg with
|
||
@code{--enable-libflite}.
|
||
|
||
Note that the flite library is not thread-safe.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
|
||
@item list_voices
|
||
If set to 1, list the names of the available voices and exit
|
||
immediately. Default value is 0.
|
||
|
||
@item nb_samples, n
|
||
Set the maximum number of samples per frame. Default value is 512.
|
||
|
||
@item textfile
|
||
Set the filename containing the text to speak.
|
||
|
||
@item text
|
||
Set the text to speak.
|
||
|
||
@item voice, v
|
||
Set the voice to use for the speech synthesis. Default value is
|
||
@code{kal}. See also the @var{list_voices} option.
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Read from file @file{speech.txt}, and synthesize the text using the
|
||
standard flite voice:
|
||
@example
|
||
flite=textfile=speech.txt
|
||
@end example
|
||
|
||
@item
|
||
Read the specified text selecting the @code{slt} voice:
|
||
@example
|
||
flite=text='So fare thee well, poor devil of a Sub-Sub, whose commentator I am':voice=slt
|
||
@end example
|
||
|
||
@item
|
||
Input text to ffmpeg:
|
||
@example
|
||
ffmpeg -f lavfi -i flite=text='So fare thee well, poor devil of a Sub-Sub, whose commentator I am':voice=slt
|
||
@end example
|
||
|
||
@item
|
||
Make @file{ffplay} speak the specified text, using @code{flite} and
|
||
the @code{lavfi} device:
|
||
@example
|
||
ffplay -f lavfi flite=text='No more be grieved for which that thou hast done.'
|
||
@end example
|
||
@end itemize
|
||
|
||
For more information about libflite, check:
|
||
@url{http://www.speech.cs.cmu.edu/flite/}
|
||
|
||
@section anoisesrc
|
||
|
||
Generate a noise audio signal.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item sample_rate, r
|
||
Specify the sample rate. Default value is 48000 Hz.
|
||
|
||
@item amplitude, a
|
||
Specify the amplitude (0.0 - 1.0) of the generated audio stream. Default value
|
||
is 1.0.
|
||
|
||
@item duration, d
|
||
Specify the duration of the generated audio stream. Not specifying this option
|
||
results in noise with an infinite length.
|
||
|
||
@item color, colour, c
|
||
Specify the color of noise. Available noise colors are white, pink, brown,
|
||
blue and violet. Default color is white.
|
||
|
||
@item seed, s
|
||
Specify a value used to seed the PRNG.
|
||
|
||
@item nb_samples, n
|
||
Set the number of samples per each output frame, default is 1024.
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
|
||
@item
|
||
Generate 60 seconds of pink noise, with a 44.1 kHz sampling rate and an amplitude of 0.5:
|
||
@example
|
||
anoisesrc=d=60:c=pink:r=44100:a=0.5
|
||
@end example
|
||
@end itemize
|
||
|
||
@section sine
|
||
|
||
Generate an audio signal made of a sine wave with amplitude 1/8.
|
||
|
||
The audio signal is bit-exact.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
|
||
@item frequency, f
|
||
Set the carrier frequency. Default is 440 Hz.
|
||
|
||
@item beep_factor, b
|
||
Enable a periodic beep every second with frequency @var{beep_factor} times
|
||
the carrier frequency. Default is 0, meaning the beep is disabled.
|
||
|
||
@item sample_rate, r
|
||
Specify the sample rate, default is 44100.
|
||
|
||
@item duration, d
|
||
Specify the duration of the generated audio stream.
|
||
|
||
@item samples_per_frame
|
||
Set the number of samples per output frame.
|
||
|
||
The expression can contain the following constants:
|
||
|
||
@table @option
|
||
@item n
|
||
The (sequential) number of the output audio frame, starting from 0.
|
||
|
||
@item pts
|
||
The PTS (Presentation TimeStamp) of the output audio frame,
|
||
expressed in @var{TB} units.
|
||
|
||
@item t
|
||
The PTS of the output audio frame, expressed in seconds.
|
||
|
||
@item TB
|
||
The timebase of the output audio frames.
|
||
@end table
|
||
|
||
Default is @code{1024}.
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
|
||
@item
|
||
Generate a simple 440 Hz sine wave:
|
||
@example
|
||
sine
|
||
@end example
|
||
|
||
@item
|
||
Generate a 220 Hz sine wave with a 880 Hz beep each second, for 5 seconds:
|
||
@example
|
||
sine=220:4:d=5
|
||
sine=f=220:b=4:d=5
|
||
sine=frequency=220:beep_factor=4:duration=5
|
||
@end example
|
||
|
||
@item
|
||
Generate a 1 kHz sine wave following @code{1602,1601,1602,1601,1602} NTSC
|
||
pattern:
|
||
@example
|
||
sine=1000:samples_per_frame='st(0,mod(n,5)); 1602-not(not(eq(ld(0),1)+eq(ld(0),3)))'
|
||
@end example
|
||
@end itemize
|
||
|
||
@c man end AUDIO SOURCES
|
||
|
||
@chapter Audio Sinks
|
||
@c man begin AUDIO SINKS
|
||
|
||
Below is a description of the currently available audio sinks.
|
||
|
||
@section abuffersink
|
||
|
||
Buffer audio frames, and make them available to the end of filter chain.
|
||
|
||
This sink is mainly intended for programmatic use, in particular
|
||
through the interface defined in @file{libavfilter/buffersink.h}
|
||
or the options system.
|
||
|
||
It accepts a pointer to an AVABufferSinkContext structure, which
|
||
defines the incoming buffers' formats, to be passed as the opaque
|
||
parameter to @code{avfilter_init_filter} for initialization.
|
||
@section anullsink
|
||
|
||
Null audio sink; do absolutely nothing with the input audio. It is
|
||
mainly useful as a template and for use in analysis / debugging
|
||
tools.
|
||
|
||
@c man end AUDIO SINKS
|
||
|
||
@chapter Video Filters
|
||
@c man begin VIDEO FILTERS
|
||
|
||
When you configure your FFmpeg build, you can disable any of the
|
||
existing filters using @code{--disable-filters}.
|
||
The configure output will show the video filters included in your
|
||
build.
|
||
|
||
Below is a description of the currently available video filters.
|
||
|
||
@section alphaextract
|
||
|
||
Extract the alpha component from the input as a grayscale video. This
|
||
is especially useful with the @var{alphamerge} filter.
|
||
|
||
@section alphamerge
|
||
|
||
Add or replace the alpha component of the primary input with the
|
||
grayscale value of a second input. This is intended for use with
|
||
@var{alphaextract} to allow the transmission or storage of frame
|
||
sequences that have alpha in a format that doesn't support an alpha
|
||
channel.
|
||
|
||
For example, to reconstruct full frames from a normal YUV-encoded video
|
||
and a separate video created with @var{alphaextract}, you might use:
|
||
@example
|
||
movie=in_alpha.mkv [alpha]; [in][alpha] alphamerge [out]
|
||
@end example
|
||
|
||
Since this filter is designed for reconstruction, it operates on frame
|
||
sequences without considering timestamps, and terminates when either
|
||
input reaches end of stream. This will cause problems if your encoding
|
||
pipeline drops frames. If you're trying to apply an image as an
|
||
overlay to a video stream, consider the @var{overlay} filter instead.
|
||
|
||
@section ass
|
||
|
||
Same as the @ref{subtitles} filter, except that it doesn't require libavcodec
|
||
and libavformat to work. On the other hand, it is limited to ASS (Advanced
|
||
Substation Alpha) subtitles files.
|
||
|
||
This filter accepts the following option in addition to the common options from
|
||
the @ref{subtitles} filter:
|
||
|
||
@table @option
|
||
@item shaping
|
||
Set the shaping engine
|
||
|
||
Available values are:
|
||
@table @samp
|
||
@item auto
|
||
The default libass shaping engine, which is the best available.
|
||
@item simple
|
||
Fast, font-agnostic shaper that can do only substitutions
|
||
@item complex
|
||
Slower shaper using OpenType for substitutions and positioning
|
||
@end table
|
||
|
||
The default is @code{auto}.
|
||
@end table
|
||
|
||
@section atadenoise
|
||
Apply an Adaptive Temporal Averaging Denoiser to the video input.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item 0a
|
||
Set threshold A for 1st plane. Default is 0.02.
|
||
Valid range is 0 to 0.3.
|
||
|
||
@item 0b
|
||
Set threshold B for 1st plane. Default is 0.04.
|
||
Valid range is 0 to 5.
|
||
|
||
@item 1a
|
||
Set threshold A for 2nd plane. Default is 0.02.
|
||
Valid range is 0 to 0.3.
|
||
|
||
@item 1b
|
||
Set threshold B for 2nd plane. Default is 0.04.
|
||
Valid range is 0 to 5.
|
||
|
||
@item 2a
|
||
Set threshold A for 3rd plane. Default is 0.02.
|
||
Valid range is 0 to 0.3.
|
||
|
||
@item 2b
|
||
Set threshold B for 3rd plane. Default is 0.04.
|
||
Valid range is 0 to 5.
|
||
|
||
Threshold A is designed to react on abrupt changes in the input signal and
|
||
threshold B is designed to react on continuous changes in the input signal.
|
||
|
||
@item s
|
||
Set number of frames filter will use for averaging. Default is 33. Must be odd
|
||
number in range [5, 129].
|
||
|
||
@item p
|
||
Set what planes of frame filter will use for averaging. Default is all.
|
||
@end table
|
||
|
||
@section avgblur
|
||
|
||
Apply average blur filter.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item sizeX
|
||
Set horizontal kernel size.
|
||
|
||
@item planes
|
||
Set which planes to filter. By default all planes are filtered.
|
||
|
||
@item sizeY
|
||
Set vertical kernel size, if zero it will be same as @code{sizeX}.
|
||
Default is @code{0}.
|
||
@end table
|
||
|
||
@section bbox
|
||
|
||
Compute the bounding box for the non-black pixels in the input frame
|
||
luminance plane.
|
||
|
||
This filter computes the bounding box containing all the pixels with a
|
||
luminance value greater than the minimum allowed value.
|
||
The parameters describing the bounding box are printed on the filter
|
||
log.
|
||
|
||
The filter accepts the following option:
|
||
|
||
@table @option
|
||
@item min_val
|
||
Set the minimal luminance value. Default is @code{16}.
|
||
@end table
|
||
|
||
@section bitplanenoise
|
||
|
||
Show and measure bit plane noise.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item bitplane
|
||
Set which plane to analyze. Default is @code{1}.
|
||
|
||
@item filter
|
||
Filter out noisy pixels from @code{bitplane} set above.
|
||
Default is disabled.
|
||
@end table
|
||
|
||
@section blackdetect
|
||
|
||
Detect video intervals that are (almost) completely black. Can be
|
||
useful to detect chapter transitions, commercials, or invalid
|
||
recordings. Output lines contains the time for the start, end and
|
||
duration of the detected black interval expressed in seconds.
|
||
|
||
In order to display the output lines, you need to set the loglevel at
|
||
least to the AV_LOG_INFO value.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item black_min_duration, d
|
||
Set the minimum detected black duration expressed in seconds. It must
|
||
be a non-negative floating point number.
|
||
|
||
Default value is 2.0.
|
||
|
||
@item picture_black_ratio_th, pic_th
|
||
Set the threshold for considering a picture "black".
|
||
Express the minimum value for the ratio:
|
||
@example
|
||
@var{nb_black_pixels} / @var{nb_pixels}
|
||
@end example
|
||
|
||
for which a picture is considered black.
|
||
Default value is 0.98.
|
||
|
||
@item pixel_black_th, pix_th
|
||
Set the threshold for considering a pixel "black".
|
||
|
||
The threshold expresses the maximum pixel luminance value for which a
|
||
pixel is considered "black". The provided value is scaled according to
|
||
the following equation:
|
||
@example
|
||
@var{absolute_threshold} = @var{luminance_minimum_value} + @var{pixel_black_th} * @var{luminance_range_size}
|
||
@end example
|
||
|
||
@var{luminance_range_size} and @var{luminance_minimum_value} depend on
|
||
the input video format, the range is [0-255] for YUV full-range
|
||
formats and [16-235] for YUV non full-range formats.
|
||
|
||
Default value is 0.10.
|
||
@end table
|
||
|
||
The following example sets the maximum pixel threshold to the minimum
|
||
value, and detects only black intervals of 2 or more seconds:
|
||
@example
|
||
blackdetect=d=2:pix_th=0.00
|
||
@end example
|
||
|
||
@section blackframe
|
||
|
||
Detect frames that are (almost) completely black. Can be useful to
|
||
detect chapter transitions or commercials. Output lines consist of
|
||
the frame number of the detected frame, the percentage of blackness,
|
||
the position in the file if known or -1 and the timestamp in seconds.
|
||
|
||
In order to display the output lines, you need to set the loglevel at
|
||
least to the AV_LOG_INFO value.
|
||
|
||
This filter exports frame metadata @code{lavfi.blackframe.pblack}.
|
||
The value represents the percentage of pixels in the picture that
|
||
are below the threshold value.
|
||
|
||
It accepts the following parameters:
|
||
|
||
@table @option
|
||
|
||
@item amount
|
||
The percentage of the pixels that have to be below the threshold; it defaults to
|
||
@code{98}.
|
||
|
||
@item threshold, thresh
|
||
The threshold below which a pixel value is considered black; it defaults to
|
||
@code{32}.
|
||
|
||
@end table
|
||
|
||
@section blend, tblend
|
||
|
||
Blend two video frames into each other.
|
||
|
||
The @code{blend} filter takes two input streams and outputs one
|
||
stream, the first input is the "top" layer and second input is
|
||
"bottom" layer. By default, the output terminates when the longest input terminates.
|
||
|
||
The @code{tblend} (time blend) filter takes two consecutive frames
|
||
from one single stream, and outputs the result obtained by blending
|
||
the new frame on top of the old frame.
|
||
|
||
A description of the accepted options follows.
|
||
|
||
@table @option
|
||
@item c0_mode
|
||
@item c1_mode
|
||
@item c2_mode
|
||
@item c3_mode
|
||
@item all_mode
|
||
Set blend mode for specific pixel component or all pixel components in case
|
||
of @var{all_mode}. Default value is @code{normal}.
|
||
|
||
Available values for component modes are:
|
||
@table @samp
|
||
@item addition
|
||
@item addition128
|
||
@item and
|
||
@item average
|
||
@item burn
|
||
@item darken
|
||
@item difference
|
||
@item difference128
|
||
@item divide
|
||
@item dodge
|
||
@item freeze
|
||
@item exclusion
|
||
@item extremity
|
||
@item glow
|
||
@item hardlight
|
||
@item hardmix
|
||
@item heat
|
||
@item lighten
|
||
@item linearlight
|
||
@item multiply
|
||
@item multiply128
|
||
@item negation
|
||
@item normal
|
||
@item or
|
||
@item overlay
|
||
@item phoenix
|
||
@item pinlight
|
||
@item reflect
|
||
@item screen
|
||
@item softlight
|
||
@item subtract
|
||
@item vividlight
|
||
@item xor
|
||
@end table
|
||
|
||
@item c0_opacity
|
||
@item c1_opacity
|
||
@item c2_opacity
|
||
@item c3_opacity
|
||
@item all_opacity
|
||
Set blend opacity for specific pixel component or all pixel components in case
|
||
of @var{all_opacity}. Only used in combination with pixel component blend modes.
|
||
|
||
@item c0_expr
|
||
@item c1_expr
|
||
@item c2_expr
|
||
@item c3_expr
|
||
@item all_expr
|
||
Set blend expression for specific pixel component or all pixel components in case
|
||
of @var{all_expr}. Note that related mode options will be ignored if those are set.
|
||
|
||
The expressions can use the following variables:
|
||
|
||
@table @option
|
||
@item N
|
||
The sequential number of the filtered frame, starting from @code{0}.
|
||
|
||
@item X
|
||
@item Y
|
||
the coordinates of the current sample
|
||
|
||
@item W
|
||
@item H
|
||
the width and height of currently filtered plane
|
||
|
||
@item SW
|
||
@item SH
|
||
Width and height scale depending on the currently filtered plane. It is the
|
||
ratio between the corresponding luma plane number of pixels and the current
|
||
plane ones. E.g. for YUV4:2:0 the values are @code{1,1} for the luma plane, and
|
||
@code{0.5,0.5} for chroma planes.
|
||
|
||
@item T
|
||
Time of the current frame, expressed in seconds.
|
||
|
||
@item TOP, A
|
||
Value of pixel component at current location for first video frame (top layer).
|
||
|
||
@item BOTTOM, B
|
||
Value of pixel component at current location for second video frame (bottom layer).
|
||
@end table
|
||
|
||
@item shortest
|
||
Force termination when the shortest input terminates. Default is
|
||
@code{0}. This option is only defined for the @code{blend} filter.
|
||
|
||
@item repeatlast
|
||
Continue applying the last bottom frame after the end of the stream. A value of
|
||
@code{0} disable the filter after the last frame of the bottom layer is reached.
|
||
Default is @code{1}. This option is only defined for the @code{blend} filter.
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Apply transition from bottom layer to top layer in first 10 seconds:
|
||
@example
|
||
blend=all_expr='A*(if(gte(T,10),1,T/10))+B*(1-(if(gte(T,10),1,T/10)))'
|
||
@end example
|
||
|
||
@item
|
||
Apply 1x1 checkerboard effect:
|
||
@example
|
||
blend=all_expr='if(eq(mod(X,2),mod(Y,2)),A,B)'
|
||
@end example
|
||
|
||
@item
|
||
Apply uncover left effect:
|
||
@example
|
||
blend=all_expr='if(gte(N*SW+X,W),A,B)'
|
||
@end example
|
||
|
||
@item
|
||
Apply uncover down effect:
|
||
@example
|
||
blend=all_expr='if(gte(Y-N*SH,0),A,B)'
|
||
@end example
|
||
|
||
@item
|
||
Apply uncover up-left effect:
|
||
@example
|
||
blend=all_expr='if(gte(T*SH*40+Y,H)*gte((T*40*SW+X)*W/H,W),A,B)'
|
||
@end example
|
||
|
||
@item
|
||
Split diagonally video and shows top and bottom layer on each side:
|
||
@example
|
||
blend=all_expr=if(gt(X,Y*(W/H)),A,B)
|
||
@end example
|
||
|
||
@item
|
||
Display differences between the current and the previous frame:
|
||
@example
|
||
tblend=all_mode=difference128
|
||
@end example
|
||
@end itemize
|
||
|
||
@section boxblur
|
||
|
||
Apply a boxblur algorithm to the input video.
|
||
|
||
It accepts the following parameters:
|
||
|
||
@table @option
|
||
|
||
@item luma_radius, lr
|
||
@item luma_power, lp
|
||
@item chroma_radius, cr
|
||
@item chroma_power, cp
|
||
@item alpha_radius, ar
|
||
@item alpha_power, ap
|
||
|
||
@end table
|
||
|
||
A description of the accepted options follows.
|
||
|
||
@table @option
|
||
@item luma_radius, lr
|
||
@item chroma_radius, cr
|
||
@item alpha_radius, ar
|
||
Set an expression for the box radius in pixels used for blurring the
|
||
corresponding input plane.
|
||
|
||
The radius value must be a non-negative number, and must not be
|
||
greater than the value of the expression @code{min(w,h)/2} for the
|
||
luma and alpha planes, and of @code{min(cw,ch)/2} for the chroma
|
||
planes.
|
||
|
||
Default value for @option{luma_radius} is "2". If not specified,
|
||
@option{chroma_radius} and @option{alpha_radius} default to the
|
||
corresponding value set for @option{luma_radius}.
|
||
|
||
The expressions can contain the following constants:
|
||
@table @option
|
||
@item w
|
||
@item h
|
||
The input width and height in pixels.
|
||
|
||
@item cw
|
||
@item ch
|
||
The input chroma image width and height in pixels.
|
||
|
||
@item hsub
|
||
@item vsub
|
||
The horizontal and vertical chroma subsample values. For example, for the
|
||
pixel format "yuv422p", @var{hsub} is 2 and @var{vsub} is 1.
|
||
@end table
|
||
|
||
@item luma_power, lp
|
||
@item chroma_power, cp
|
||
@item alpha_power, ap
|
||
Specify how many times the boxblur filter is applied to the
|
||
corresponding plane.
|
||
|
||
Default value for @option{luma_power} is 2. If not specified,
|
||
@option{chroma_power} and @option{alpha_power} default to the
|
||
corresponding value set for @option{luma_power}.
|
||
|
||
A value of 0 will disable the effect.
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Apply a boxblur filter with the luma, chroma, and alpha radii
|
||
set to 2:
|
||
@example
|
||
boxblur=luma_radius=2:luma_power=1
|
||
boxblur=2:1
|
||
@end example
|
||
|
||
@item
|
||
Set the luma radius to 2, and alpha and chroma radius to 0:
|
||
@example
|
||
boxblur=2:1:cr=0:ar=0
|
||
@end example
|
||
|
||
@item
|
||
Set the luma and chroma radii to a fraction of the video dimension:
|
||
@example
|
||
boxblur=luma_radius=min(h\,w)/10:luma_power=1:chroma_radius=min(cw\,ch)/10:chroma_power=1
|
||
@end example
|
||
@end itemize
|
||
|
||
@section bwdif
|
||
|
||
Deinterlace the input video ("bwdif" stands for "Bob Weaver
|
||
Deinterlacing Filter").
|
||
|
||
Motion adaptive deinterlacing based on yadif with the use of w3fdif and cubic
|
||
interpolation algorithms.
|
||
It accepts the following parameters:
|
||
|
||
@table @option
|
||
@item mode
|
||
The interlacing mode to adopt. It accepts one of the following values:
|
||
|
||
@table @option
|
||
@item 0, send_frame
|
||
Output one frame for each frame.
|
||
@item 1, send_field
|
||
Output one frame for each field.
|
||
@end table
|
||
|
||
The default value is @code{send_field}.
|
||
|
||
@item parity
|
||
The picture field parity assumed for the input interlaced video. It accepts one
|
||
of the following values:
|
||
|
||
@table @option
|
||
@item 0, tff
|
||
Assume the top field is first.
|
||
@item 1, bff
|
||
Assume the bottom field is first.
|
||
@item -1, auto
|
||
Enable automatic detection of field parity.
|
||
@end table
|
||
|
||
The default value is @code{auto}.
|
||
If the interlacing is unknown or the decoder does not export this information,
|
||
top field first will be assumed.
|
||
|
||
@item deint
|
||
Specify which frames to deinterlace. Accept one of the following
|
||
values:
|
||
|
||
@table @option
|
||
@item 0, all
|
||
Deinterlace all frames.
|
||
@item 1, interlaced
|
||
Only deinterlace frames marked as interlaced.
|
||
@end table
|
||
|
||
The default value is @code{all}.
|
||
@end table
|
||
|
||
@section chromakey
|
||
YUV colorspace color/chroma keying.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item color
|
||
The color which will be replaced with transparency.
|
||
|
||
@item similarity
|
||
Similarity percentage with the key color.
|
||
|
||
0.01 matches only the exact key color, while 1.0 matches everything.
|
||
|
||
@item blend
|
||
Blend percentage.
|
||
|
||
0.0 makes pixels either fully transparent, or not transparent at all.
|
||
|
||
Higher values result in semi-transparent pixels, with a higher transparency
|
||
the more similar the pixels color is to the key color.
|
||
|
||
@item yuv
|
||
Signals that the color passed is already in YUV instead of RGB.
|
||
|
||
Litteral colors like "green" or "red" don't make sense with this enabled anymore.
|
||
This can be used to pass exact YUV values as hexadecimal numbers.
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Make every green pixel in the input image transparent:
|
||
@example
|
||
ffmpeg -i input.png -vf chromakey=green out.png
|
||
@end example
|
||
|
||
@item
|
||
Overlay a greenscreen-video on top of a static black background.
|
||
@example
|
||
ffmpeg -f lavfi -i color=c=black:s=1280x720 -i video.mp4 -shortest -filter_complex "[1:v]chromakey=0x70de77:0.1:0.2[ckout];[0:v][ckout]overlay[out]" -map "[out]" output.mkv
|
||
@end example
|
||
@end itemize
|
||
|
||
@section ciescope
|
||
|
||
Display CIE color diagram with pixels overlaid onto it.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item system
|
||
Set color system.
|
||
|
||
@table @samp
|
||
@item ntsc, 470m
|
||
@item ebu, 470bg
|
||
@item smpte
|
||
@item 240m
|
||
@item apple
|
||
@item widergb
|
||
@item cie1931
|
||
@item rec709, hdtv
|
||
@item uhdtv, rec2020
|
||
@end table
|
||
|
||
@item cie
|
||
Set CIE system.
|
||
|
||
@table @samp
|
||
@item xyy
|
||
@item ucs
|
||
@item luv
|
||
@end table
|
||
|
||
@item gamuts
|
||
Set what gamuts to draw.
|
||
|
||
See @code{system} option for available values.
|
||
|
||
@item size, s
|
||
Set ciescope size, by default set to 512.
|
||
|
||
@item intensity, i
|
||
Set intensity used to map input pixel values to CIE diagram.
|
||
|
||
@item contrast
|
||
Set contrast used to draw tongue colors that are out of active color system gamut.
|
||
|
||
@item corrgamma
|
||
Correct gamma displayed on scope, by default enabled.
|
||
|
||
@item showwhite
|
||
Show white point on CIE diagram, by default disabled.
|
||
|
||
@item gamma
|
||
Set input gamma. Used only with XYZ input color space.
|
||
@end table
|
||
|
||
@section codecview
|
||
|
||
Visualize information exported by some codecs.
|
||
|
||
Some codecs can export information through frames using side-data or other
|
||
means. For example, some MPEG based codecs export motion vectors through the
|
||
@var{export_mvs} flag in the codec @option{flags2} option.
|
||
|
||
The filter accepts the following option:
|
||
|
||
@table @option
|
||
@item mv
|
||
Set motion vectors to visualize.
|
||
|
||
Available flags for @var{mv} are:
|
||
|
||
@table @samp
|
||
@item pf
|
||
forward predicted MVs of P-frames
|
||
@item bf
|
||
forward predicted MVs of B-frames
|
||
@item bb
|
||
backward predicted MVs of B-frames
|
||
@end table
|
||
|
||
@item qp
|
||
Display quantization parameters using the chroma planes.
|
||
|
||
@item mv_type, mvt
|
||
Set motion vectors type to visualize. Includes MVs from all frames unless specified by @var{frame_type} option.
|
||
|
||
Available flags for @var{mv_type} are:
|
||
|
||
@table @samp
|
||
@item fp
|
||
forward predicted MVs
|
||
@item bp
|
||
backward predicted MVs
|
||
@end table
|
||
|
||
@item frame_type, ft
|
||
Set frame type to visualize motion vectors of.
|
||
|
||
Available flags for @var{frame_type} are:
|
||
|
||
@table @samp
|
||
@item if
|
||
intra-coded frames (I-frames)
|
||
@item pf
|
||
predicted frames (P-frames)
|
||
@item bf
|
||
bi-directionally predicted frames (B-frames)
|
||
@end table
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Visualize forward predicted MVs of all frames using @command{ffplay}:
|
||
@example
|
||
ffplay -flags2 +export_mvs input.mp4 -vf codecview=mv_type=fp
|
||
@end example
|
||
|
||
@item
|
||
Visualize multi-directionals MVs of P and B-Frames using @command{ffplay}:
|
||
@example
|
||
ffplay -flags2 +export_mvs input.mp4 -vf codecview=mv=pf+bf+bb
|
||
@end example
|
||
@end itemize
|
||
|
||
@section colorbalance
|
||
Modify intensity of primary colors (red, green and blue) of input frames.
|
||
|
||
The filter allows an input frame to be adjusted in the shadows, midtones or highlights
|
||
regions for the red-cyan, green-magenta or blue-yellow balance.
|
||
|
||
A positive adjustment value shifts the balance towards the primary color, a negative
|
||
value towards the complementary color.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item rs
|
||
@item gs
|
||
@item bs
|
||
Adjust red, green and blue shadows (darkest pixels).
|
||
|
||
@item rm
|
||
@item gm
|
||
@item bm
|
||
Adjust red, green and blue midtones (medium pixels).
|
||
|
||
@item rh
|
||
@item gh
|
||
@item bh
|
||
Adjust red, green and blue highlights (brightest pixels).
|
||
|
||
Allowed ranges for options are @code{[-1.0, 1.0]}. Defaults are @code{0}.
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Add red color cast to shadows:
|
||
@example
|
||
colorbalance=rs=.3
|
||
@end example
|
||
@end itemize
|
||
|
||
@section colorkey
|
||
RGB colorspace color keying.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item color
|
||
The color which will be replaced with transparency.
|
||
|
||
@item similarity
|
||
Similarity percentage with the key color.
|
||
|
||
0.01 matches only the exact key color, while 1.0 matches everything.
|
||
|
||
@item blend
|
||
Blend percentage.
|
||
|
||
0.0 makes pixels either fully transparent, or not transparent at all.
|
||
|
||
Higher values result in semi-transparent pixels, with a higher transparency
|
||
the more similar the pixels color is to the key color.
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Make every green pixel in the input image transparent:
|
||
@example
|
||
ffmpeg -i input.png -vf colorkey=green out.png
|
||
@end example
|
||
|
||
@item
|
||
Overlay a greenscreen-video on top of a static background image.
|
||
@example
|
||
ffmpeg -i background.png -i video.mp4 -filter_complex "[1:v]colorkey=0x3BBD1E:0.3:0.2[ckout];[0:v][ckout]overlay[out]" -map "[out]" output.flv
|
||
@end example
|
||
@end itemize
|
||
|
||
@section colorlevels
|
||
|
||
Adjust video input frames using levels.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item rimin
|
||
@item gimin
|
||
@item bimin
|
||
@item aimin
|
||
Adjust red, green, blue and alpha input black point.
|
||
Allowed ranges for options are @code{[-1.0, 1.0]}. Defaults are @code{0}.
|
||
|
||
@item rimax
|
||
@item gimax
|
||
@item bimax
|
||
@item aimax
|
||
Adjust red, green, blue and alpha input white point.
|
||
Allowed ranges for options are @code{[-1.0, 1.0]}. Defaults are @code{1}.
|
||
|
||
Input levels are used to lighten highlights (bright tones), darken shadows
|
||
(dark tones), change the balance of bright and dark tones.
|
||
|
||
@item romin
|
||
@item gomin
|
||
@item bomin
|
||
@item aomin
|
||
Adjust red, green, blue and alpha output black point.
|
||
Allowed ranges for options are @code{[0, 1.0]}. Defaults are @code{0}.
|
||
|
||
@item romax
|
||
@item gomax
|
||
@item bomax
|
||
@item aomax
|
||
Adjust red, green, blue and alpha output white point.
|
||
Allowed ranges for options are @code{[0, 1.0]}. Defaults are @code{1}.
|
||
|
||
Output levels allows manual selection of a constrained output level range.
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Make video output darker:
|
||
@example
|
||
colorlevels=rimin=0.058:gimin=0.058:bimin=0.058
|
||
@end example
|
||
|
||
@item
|
||
Increase contrast:
|
||
@example
|
||
colorlevels=rimin=0.039:gimin=0.039:bimin=0.039:rimax=0.96:gimax=0.96:bimax=0.96
|
||
@end example
|
||
|
||
@item
|
||
Make video output lighter:
|
||
@example
|
||
colorlevels=rimax=0.902:gimax=0.902:bimax=0.902
|
||
@end example
|
||
|
||
@item
|
||
Increase brightness:
|
||
@example
|
||
colorlevels=romin=0.5:gomin=0.5:bomin=0.5
|
||
@end example
|
||
@end itemize
|
||
|
||
@section colorchannelmixer
|
||
|
||
Adjust video input frames by re-mixing color channels.
|
||
|
||
This filter modifies a color channel by adding the values associated to
|
||
the other channels of the same pixels. For example if the value to
|
||
modify is red, the output value will be:
|
||
@example
|
||
@var{red}=@var{red}*@var{rr} + @var{blue}*@var{rb} + @var{green}*@var{rg} + @var{alpha}*@var{ra}
|
||
@end example
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item rr
|
||
@item rg
|
||
@item rb
|
||
@item ra
|
||
Adjust contribution of input red, green, blue and alpha channels for output red channel.
|
||
Default is @code{1} for @var{rr}, and @code{0} for @var{rg}, @var{rb} and @var{ra}.
|
||
|
||
@item gr
|
||
@item gg
|
||
@item gb
|
||
@item ga
|
||
Adjust contribution of input red, green, blue and alpha channels for output green channel.
|
||
Default is @code{1} for @var{gg}, and @code{0} for @var{gr}, @var{gb} and @var{ga}.
|
||
|
||
@item br
|
||
@item bg
|
||
@item bb
|
||
@item ba
|
||
Adjust contribution of input red, green, blue and alpha channels for output blue channel.
|
||
Default is @code{1} for @var{bb}, and @code{0} for @var{br}, @var{bg} and @var{ba}.
|
||
|
||
@item ar
|
||
@item ag
|
||
@item ab
|
||
@item aa
|
||
Adjust contribution of input red, green, blue and alpha channels for output alpha channel.
|
||
Default is @code{1} for @var{aa}, and @code{0} for @var{ar}, @var{ag} and @var{ab}.
|
||
|
||
Allowed ranges for options are @code{[-2.0, 2.0]}.
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Convert source to grayscale:
|
||
@example
|
||
colorchannelmixer=.3:.4:.3:0:.3:.4:.3:0:.3:.4:.3
|
||
@end example
|
||
@item
|
||
Simulate sepia tones:
|
||
@example
|
||
colorchannelmixer=.393:.769:.189:0:.349:.686:.168:0:.272:.534:.131
|
||
@end example
|
||
@end itemize
|
||
|
||
@section colormatrix
|
||
|
||
Convert color matrix.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item src
|
||
@item dst
|
||
Specify the source and destination color matrix. Both values must be
|
||
specified.
|
||
|
||
The accepted values are:
|
||
@table @samp
|
||
@item bt709
|
||
BT.709
|
||
|
||
@item fcc
|
||
FCC
|
||
|
||
@item bt601
|
||
BT.601
|
||
|
||
@item bt470
|
||
BT.470
|
||
|
||
@item bt470bg
|
||
BT.470BG
|
||
|
||
@item smpte170m
|
||
SMPTE-170M
|
||
|
||
@item smpte240m
|
||
SMPTE-240M
|
||
|
||
@item bt2020
|
||
BT.2020
|
||
@end table
|
||
@end table
|
||
|
||
For example to convert from BT.601 to SMPTE-240M, use the command:
|
||
@example
|
||
colormatrix=bt601:smpte240m
|
||
@end example
|
||
|
||
@section colorspace
|
||
|
||
Convert colorspace, transfer characteristics or color primaries.
|
||
Input video needs to have an even size.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@anchor{all}
|
||
@item all
|
||
Specify all color properties at once.
|
||
|
||
The accepted values are:
|
||
@table @samp
|
||
@item bt470m
|
||
BT.470M
|
||
|
||
@item bt470bg
|
||
BT.470BG
|
||
|
||
@item bt601-6-525
|
||
BT.601-6 525
|
||
|
||
@item bt601-6-625
|
||
BT.601-6 625
|
||
|
||
@item bt709
|
||
BT.709
|
||
|
||
@item smpte170m
|
||
SMPTE-170M
|
||
|
||
@item smpte240m
|
||
SMPTE-240M
|
||
|
||
@item bt2020
|
||
BT.2020
|
||
|
||
@end table
|
||
|
||
@anchor{space}
|
||
@item space
|
||
Specify output colorspace.
|
||
|
||
The accepted values are:
|
||
@table @samp
|
||
@item bt709
|
||
BT.709
|
||
|
||
@item fcc
|
||
FCC
|
||
|
||
@item bt470bg
|
||
BT.470BG or BT.601-6 625
|
||
|
||
@item smpte170m
|
||
SMPTE-170M or BT.601-6 525
|
||
|
||
@item smpte240m
|
||
SMPTE-240M
|
||
|
||
@item ycgco
|
||
YCgCo
|
||
|
||
@item bt2020ncl
|
||
BT.2020 with non-constant luminance
|
||
|
||
@end table
|
||
|
||
@anchor{trc}
|
||
@item trc
|
||
Specify output transfer characteristics.
|
||
|
||
The accepted values are:
|
||
@table @samp
|
||
@item bt709
|
||
BT.709
|
||
|
||
@item bt470m
|
||
BT.470M
|
||
|
||
@item bt470bg
|
||
BT.470BG
|
||
|
||
@item gamma22
|
||
Constant gamma of 2.2
|
||
|
||
@item gamma28
|
||
Constant gamma of 2.8
|
||
|
||
@item smpte170m
|
||
SMPTE-170M, BT.601-6 625 or BT.601-6 525
|
||
|
||
@item smpte240m
|
||
SMPTE-240M
|
||
|
||
@item srgb
|
||
SRGB
|
||
|
||
@item iec61966-2-1
|
||
iec61966-2-1
|
||
|
||
@item iec61966-2-4
|
||
iec61966-2-4
|
||
|
||
@item xvycc
|
||
xvycc
|
||
|
||
@item bt2020-10
|
||
BT.2020 for 10-bits content
|
||
|
||
@item bt2020-12
|
||
BT.2020 for 12-bits content
|
||
|
||
@end table
|
||
|
||
@anchor{primaries}
|
||
@item primaries
|
||
Specify output color primaries.
|
||
|
||
The accepted values are:
|
||
@table @samp
|
||
@item bt709
|
||
BT.709
|
||
|
||
@item bt470m
|
||
BT.470M
|
||
|
||
@item bt470bg
|
||
BT.470BG or BT.601-6 625
|
||
|
||
@item smpte170m
|
||
SMPTE-170M or BT.601-6 525
|
||
|
||
@item smpte240m
|
||
SMPTE-240M
|
||
|
||
@item film
|
||
film
|
||
|
||
@item smpte431
|
||
SMPTE-431
|
||
|
||
@item smpte432
|
||
SMPTE-432
|
||
|
||
@item bt2020
|
||
BT.2020
|
||
|
||
@item jedec-p22
|
||
JEDEC P22 phosphors
|
||
|
||
@end table
|
||
|
||
@anchor{range}
|
||
@item range
|
||
Specify output color range.
|
||
|
||
The accepted values are:
|
||
@table @samp
|
||
@item tv
|
||
TV (restricted) range
|
||
|
||
@item mpeg
|
||
MPEG (restricted) range
|
||
|
||
@item pc
|
||
PC (full) range
|
||
|
||
@item jpeg
|
||
JPEG (full) range
|
||
|
||
@end table
|
||
|
||
@item format
|
||
Specify output color format.
|
||
|
||
The accepted values are:
|
||
@table @samp
|
||
@item yuv420p
|
||
YUV 4:2:0 planar 8-bits
|
||
|
||
@item yuv420p10
|
||
YUV 4:2:0 planar 10-bits
|
||
|
||
@item yuv420p12
|
||
YUV 4:2:0 planar 12-bits
|
||
|
||
@item yuv422p
|
||
YUV 4:2:2 planar 8-bits
|
||
|
||
@item yuv422p10
|
||
YUV 4:2:2 planar 10-bits
|
||
|
||
@item yuv422p12
|
||
YUV 4:2:2 planar 12-bits
|
||
|
||
@item yuv444p
|
||
YUV 4:4:4 planar 8-bits
|
||
|
||
@item yuv444p10
|
||
YUV 4:4:4 planar 10-bits
|
||
|
||
@item yuv444p12
|
||
YUV 4:4:4 planar 12-bits
|
||
|
||
@end table
|
||
|
||
@item fast
|
||
Do a fast conversion, which skips gamma/primary correction. This will take
|
||
significantly less CPU, but will be mathematically incorrect. To get output
|
||
compatible with that produced by the colormatrix filter, use fast=1.
|
||
|
||
@item dither
|
||
Specify dithering mode.
|
||
|
||
The accepted values are:
|
||
@table @samp
|
||
@item none
|
||
No dithering
|
||
|
||
@item fsb
|
||
Floyd-Steinberg dithering
|
||
@end table
|
||
|
||
@item wpadapt
|
||
Whitepoint adaptation mode.
|
||
|
||
The accepted values are:
|
||
@table @samp
|
||
@item bradford
|
||
Bradford whitepoint adaptation
|
||
|
||
@item vonkries
|
||
von Kries whitepoint adaptation
|
||
|
||
@item identity
|
||
identity whitepoint adaptation (i.e. no whitepoint adaptation)
|
||
@end table
|
||
|
||
@item iall
|
||
Override all input properties at once. Same accepted values as @ref{all}.
|
||
|
||
@item ispace
|
||
Override input colorspace. Same accepted values as @ref{space}.
|
||
|
||
@item iprimaries
|
||
Override input color primaries. Same accepted values as @ref{primaries}.
|
||
|
||
@item itrc
|
||
Override input transfer characteristics. Same accepted values as @ref{trc}.
|
||
|
||
@item irange
|
||
Override input color range. Same accepted values as @ref{range}.
|
||
|
||
@end table
|
||
|
||
The filter converts the transfer characteristics, color space and color
|
||
primaries to the specified user values. The output value, if not specified,
|
||
is set to a default value based on the "all" property. If that property is
|
||
also not specified, the filter will log an error. The output color range and
|
||
format default to the same value as the input color range and format. The
|
||
input transfer characteristics, color space, color primaries and color range
|
||
should be set on the input data. If any of these are missing, the filter will
|
||
log an error and no conversion will take place.
|
||
|
||
For example to convert the input to SMPTE-240M, use the command:
|
||
@example
|
||
colorspace=smpte240m
|
||
@end example
|
||
|
||
@section convolution
|
||
|
||
Apply convolution 3x3 or 5x5 filter.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item 0m
|
||
@item 1m
|
||
@item 2m
|
||
@item 3m
|
||
Set matrix for each plane.
|
||
Matrix is sequence of 9 or 25 signed integers.
|
||
|
||
@item 0rdiv
|
||
@item 1rdiv
|
||
@item 2rdiv
|
||
@item 3rdiv
|
||
Set multiplier for calculated value for each plane.
|
||
|
||
@item 0bias
|
||
@item 1bias
|
||
@item 2bias
|
||
@item 3bias
|
||
Set bias for each plane. This value is added to the result of the multiplication.
|
||
Useful for making the overall image brighter or darker. Default is 0.0.
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Apply sharpen:
|
||
@example
|
||
convolution="0 -1 0 -1 5 -1 0 -1 0:0 -1 0 -1 5 -1 0 -1 0:0 -1 0 -1 5 -1 0 -1 0:0 -1 0 -1 5 -1 0 -1 0"
|
||
@end example
|
||
|
||
@item
|
||
Apply blur:
|
||
@example
|
||
convolution="1 1 1 1 1 1 1 1 1:1 1 1 1 1 1 1 1 1:1 1 1 1 1 1 1 1 1:1 1 1 1 1 1 1 1 1:1/9:1/9:1/9:1/9"
|
||
@end example
|
||
|
||
@item
|
||
Apply edge enhance:
|
||
@example
|
||
convolution="0 0 0 -1 1 0 0 0 0:0 0 0 -1 1 0 0 0 0:0 0 0 -1 1 0 0 0 0:0 0 0 -1 1 0 0 0 0:5:1:1:1:0:128:128:128"
|
||
@end example
|
||
|
||
@item
|
||
Apply edge detect:
|
||
@example
|
||
convolution="0 1 0 1 -4 1 0 1 0:0 1 0 1 -4 1 0 1 0:0 1 0 1 -4 1 0 1 0:0 1 0 1 -4 1 0 1 0:5:5:5:1:0:128:128:128"
|
||
@end example
|
||
|
||
@item
|
||
Apply emboss:
|
||
@example
|
||
convolution="-2 -1 0 -1 1 1 0 1 2:-2 -1 0 -1 1 1 0 1 2:-2 -1 0 -1 1 1 0 1 2:-2 -1 0 -1 1 1 0 1 2"
|
||
@end example
|
||
@end itemize
|
||
|
||
@section copy
|
||
|
||
Copy the input video source unchanged to the output. This is mainly useful for
|
||
testing purposes.
|
||
|
||
@anchor{coreimage}
|
||
@section coreimage
|
||
Video filtering on GPU using Apple's CoreImage API on OSX.
|
||
|
||
Hardware acceleration is based on an OpenGL context. Usually, this means it is
|
||
processed by video hardware. However, software-based OpenGL implementations
|
||
exist which means there is no guarantee for hardware processing. It depends on
|
||
the respective OSX.
|
||
|
||
There are many filters and image generators provided by Apple that come with a
|
||
large variety of options. The filter has to be referenced by its name along
|
||
with its options.
|
||
|
||
The coreimage filter accepts the following options:
|
||
@table @option
|
||
@item list_filters
|
||
List all available filters and generators along with all their respective
|
||
options as well as possible minimum and maximum values along with the default
|
||
values.
|
||
@example
|
||
list_filters=true
|
||
@end example
|
||
|
||
@item filter
|
||
Specify all filters by their respective name and options.
|
||
Use @var{list_filters} to determine all valid filter names and options.
|
||
Numerical options are specified by a float value and are automatically clamped
|
||
to their respective value range. Vector and color options have to be specified
|
||
by a list of space separated float values. Character escaping has to be done.
|
||
A special option name @code{default} is available to use default options for a
|
||
filter.
|
||
|
||
It is required to specify either @code{default} or at least one of the filter options.
|
||
All omitted options are used with their default values.
|
||
The syntax of the filter string is as follows:
|
||
@example
|
||
filter=<NAME>@@<OPTION>=<VALUE>[@@<OPTION>=<VALUE>][@@...][#<NAME>@@<OPTION>=<VALUE>[@@<OPTION>=<VALUE>][@@...]][#...]
|
||
@end example
|
||
|
||
@item output_rect
|
||
Specify a rectangle where the output of the filter chain is copied into the
|
||
input image. It is given by a list of space separated float values:
|
||
@example
|
||
output_rect=x\ y\ width\ height
|
||
@end example
|
||
If not given, the output rectangle equals the dimensions of the input image.
|
||
The output rectangle is automatically cropped at the borders of the input
|
||
image. Negative values are valid for each component.
|
||
@example
|
||
output_rect=25\ 25\ 100\ 100
|
||
@end example
|
||
@end table
|
||
|
||
Several filters can be chained for successive processing without GPU-HOST
|
||
transfers allowing for fast processing of complex filter chains.
|
||
Currently, only filters with zero (generators) or exactly one (filters) input
|
||
image and one output image are supported. Also, transition filters are not yet
|
||
usable as intended.
|
||
|
||
Some filters generate output images with additional padding depending on the
|
||
respective filter kernel. The padding is automatically removed to ensure the
|
||
filter output has the same size as the input image.
|
||
|
||
For image generators, the size of the output image is determined by the
|
||
previous output image of the filter chain or the input image of the whole
|
||
filterchain, respectively. The generators do not use the pixel information of
|
||
this image to generate their output. However, the generated output is
|
||
blended onto this image, resulting in partial or complete coverage of the
|
||
output image.
|
||
|
||
The @ref{coreimagesrc} video source can be used for generating input images
|
||
which are directly fed into the filter chain. By using it, providing input
|
||
images by another video source or an input video is not required.
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
|
||
@item
|
||
List all filters available:
|
||
@example
|
||
coreimage=list_filters=true
|
||
@end example
|
||
|
||
@item
|
||
Use the CIBoxBlur filter with default options to blur an image:
|
||
@example
|
||
coreimage=filter=CIBoxBlur@@default
|
||
@end example
|
||
|
||
@item
|
||
Use a filter chain with CISepiaTone at default values and CIVignetteEffect with
|
||
its center at 100x100 and a radius of 50 pixels:
|
||
@example
|
||
coreimage=filter=CIBoxBlur@@default#CIVignetteEffect@@inputCenter=100\ 100@@inputRadius=50
|
||
@end example
|
||
|
||
@item
|
||
Use nullsrc and CIQRCodeGenerator to create a QR code for the FFmpeg homepage,
|
||
given as complete and escaped command-line for Apple's standard bash shell:
|
||
@example
|
||
ffmpeg -f lavfi -i nullsrc=s=100x100,coreimage=filter=CIQRCodeGenerator@@inputMessage=https\\\\\://FFmpeg.org/@@inputCorrectionLevel=H -frames:v 1 QRCode.png
|
||
@end example
|
||
@end itemize
|
||
|
||
@section crop
|
||
|
||
Crop the input video to given dimensions.
|
||
|
||
It accepts the following parameters:
|
||
|
||
@table @option
|
||
@item w, out_w
|
||
The width of the output video. It defaults to @code{iw}.
|
||
This expression is evaluated only once during the filter
|
||
configuration, or when the @samp{w} or @samp{out_w} command is sent.
|
||
|
||
@item h, out_h
|
||
The height of the output video. It defaults to @code{ih}.
|
||
This expression is evaluated only once during the filter
|
||
configuration, or when the @samp{h} or @samp{out_h} command is sent.
|
||
|
||
@item x
|
||
The horizontal position, in the input video, of the left edge of the output
|
||
video. It defaults to @code{(in_w-out_w)/2}.
|
||
This expression is evaluated per-frame.
|
||
|
||
@item y
|
||
The vertical position, in the input video, of the top edge of the output video.
|
||
It defaults to @code{(in_h-out_h)/2}.
|
||
This expression is evaluated per-frame.
|
||
|
||
@item keep_aspect
|
||
If set to 1 will force the output display aspect ratio
|
||
to be the same of the input, by changing the output sample aspect
|
||
ratio. It defaults to 0.
|
||
|
||
@item exact
|
||
Enable exact cropping. If enabled, subsampled videos will be cropped at exact
|
||
width/height/x/y as specified and will not be rounded to nearest smaller value.
|
||
It defaults to 0.
|
||
@end table
|
||
|
||
The @var{out_w}, @var{out_h}, @var{x}, @var{y} parameters are
|
||
expressions containing the following constants:
|
||
|
||
@table @option
|
||
@item x
|
||
@item y
|
||
The computed values for @var{x} and @var{y}. They are evaluated for
|
||
each new frame.
|
||
|
||
@item in_w
|
||
@item in_h
|
||
The input width and height.
|
||
|
||
@item iw
|
||
@item ih
|
||
These are the same as @var{in_w} and @var{in_h}.
|
||
|
||
@item out_w
|
||
@item out_h
|
||
The output (cropped) width and height.
|
||
|
||
@item ow
|
||
@item oh
|
||
These are the same as @var{out_w} and @var{out_h}.
|
||
|
||
@item a
|
||
same as @var{iw} / @var{ih}
|
||
|
||
@item sar
|
||
input sample aspect ratio
|
||
|
||
@item dar
|
||
input display aspect ratio, it is the same as (@var{iw} / @var{ih}) * @var{sar}
|
||
|
||
@item hsub
|
||
@item vsub
|
||
horizontal and vertical chroma subsample values. For example for the
|
||
pixel format "yuv422p" @var{hsub} is 2 and @var{vsub} is 1.
|
||
|
||
@item n
|
||
The number of the input frame, starting from 0.
|
||
|
||
@item pos
|
||
the position in the file of the input frame, NAN if unknown
|
||
|
||
@item t
|
||
The timestamp expressed in seconds. It's NAN if the input timestamp is unknown.
|
||
|
||
@end table
|
||
|
||
The expression for @var{out_w} may depend on the value of @var{out_h},
|
||
and the expression for @var{out_h} may depend on @var{out_w}, but they
|
||
cannot depend on @var{x} and @var{y}, as @var{x} and @var{y} are
|
||
evaluated after @var{out_w} and @var{out_h}.
|
||
|
||
The @var{x} and @var{y} parameters specify the expressions for the
|
||
position of the top-left corner of the output (non-cropped) area. They
|
||
are evaluated for each frame. If the evaluated value is not valid, it
|
||
is approximated to the nearest valid value.
|
||
|
||
The expression for @var{x} may depend on @var{y}, and the expression
|
||
for @var{y} may depend on @var{x}.
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Crop area with size 100x100 at position (12,34).
|
||
@example
|
||
crop=100:100:12:34
|
||
@end example
|
||
|
||
Using named options, the example above becomes:
|
||
@example
|
||
crop=w=100:h=100:x=12:y=34
|
||
@end example
|
||
|
||
@item
|
||
Crop the central input area with size 100x100:
|
||
@example
|
||
crop=100:100
|
||
@end example
|
||
|
||
@item
|
||
Crop the central input area with size 2/3 of the input video:
|
||
@example
|
||
crop=2/3*in_w:2/3*in_h
|
||
@end example
|
||
|
||
@item
|
||
Crop the input video central square:
|
||
@example
|
||
crop=out_w=in_h
|
||
crop=in_h
|
||
@end example
|
||
|
||
@item
|
||
Delimit the rectangle with the top-left corner placed at position
|
||
100:100 and the right-bottom corner corresponding to the right-bottom
|
||
corner of the input image.
|
||
@example
|
||
crop=in_w-100:in_h-100:100:100
|
||
@end example
|
||
|
||
@item
|
||
Crop 10 pixels from the left and right borders, and 20 pixels from
|
||
the top and bottom borders
|
||
@example
|
||
crop=in_w-2*10:in_h-2*20
|
||
@end example
|
||
|
||
@item
|
||
Keep only the bottom right quarter of the input image:
|
||
@example
|
||
crop=in_w/2:in_h/2:in_w/2:in_h/2
|
||
@end example
|
||
|
||
@item
|
||
Crop height for getting Greek harmony:
|
||
@example
|
||
crop=in_w:1/PHI*in_w
|
||
@end example
|
||
|
||
@item
|
||
Apply trembling effect:
|
||
@example
|
||
crop=in_w/2:in_h/2:(in_w-out_w)/2+((in_w-out_w)/2)*sin(n/10):(in_h-out_h)/2 +((in_h-out_h)/2)*sin(n/7)
|
||
@end example
|
||
|
||
@item
|
||
Apply erratic camera effect depending on timestamp:
|
||
@example
|
||
crop=in_w/2:in_h/2:(in_w-out_w)/2+((in_w-out_w)/2)*sin(t*10):(in_h-out_h)/2 +((in_h-out_h)/2)*sin(t*13)"
|
||
@end example
|
||
|
||
@item
|
||
Set x depending on the value of y:
|
||
@example
|
||
crop=in_w/2:in_h/2:y:10+10*sin(n/10)
|
||
@end example
|
||
@end itemize
|
||
|
||
@subsection Commands
|
||
|
||
This filter supports the following commands:
|
||
@table @option
|
||
@item w, out_w
|
||
@item h, out_h
|
||
@item x
|
||
@item y
|
||
Set width/height of the output video and the horizontal/vertical position
|
||
in the input video.
|
||
The command accepts the same syntax of the corresponding option.
|
||
|
||
If the specified expression is not valid, it is kept at its current
|
||
value.
|
||
@end table
|
||
|
||
@section cropdetect
|
||
|
||
Auto-detect the crop size.
|
||
|
||
It calculates the necessary cropping parameters and prints the
|
||
recommended parameters via the logging system. The detected dimensions
|
||
correspond to the non-black area of the input video.
|
||
|
||
It accepts the following parameters:
|
||
|
||
@table @option
|
||
|
||
@item limit
|
||
Set higher black value threshold, which can be optionally specified
|
||
from nothing (0) to everything (255 for 8-bit based formats). An intensity
|
||
value greater to the set value is considered non-black. It defaults to 24.
|
||
You can also specify a value between 0.0 and 1.0 which will be scaled depending
|
||
on the bitdepth of the pixel format.
|
||
|
||
@item round
|
||
The value which the width/height should be divisible by. It defaults to
|
||
16. The offset is automatically adjusted to center the video. Use 2 to
|
||
get only even dimensions (needed for 4:2:2 video). 16 is best when
|
||
encoding to most video codecs.
|
||
|
||
@item reset_count, reset
|
||
Set the counter that determines after how many frames cropdetect will
|
||
reset the previously detected largest video area and start over to
|
||
detect the current optimal crop area. Default value is 0.
|
||
|
||
This can be useful when channel logos distort the video area. 0
|
||
indicates 'never reset', and returns the largest area encountered during
|
||
playback.
|
||
@end table
|
||
|
||
@anchor{curves}
|
||
@section curves
|
||
|
||
Apply color adjustments using curves.
|
||
|
||
This filter is similar to the Adobe Photoshop and GIMP curves tools. Each
|
||
component (red, green and blue) has its values defined by @var{N} key points
|
||
tied from each other using a smooth curve. The x-axis represents the pixel
|
||
values from the input frame, and the y-axis the new pixel values to be set for
|
||
the output frame.
|
||
|
||
By default, a component curve is defined by the two points @var{(0;0)} and
|
||
@var{(1;1)}. This creates a straight line where each original pixel value is
|
||
"adjusted" to its own value, which means no change to the image.
|
||
|
||
The filter allows you to redefine these two points and add some more. A new
|
||
curve (using a natural cubic spline interpolation) will be define to pass
|
||
smoothly through all these new coordinates. The new defined points needs to be
|
||
strictly increasing over the x-axis, and their @var{x} and @var{y} values must
|
||
be in the @var{[0;1]} interval. If the computed curves happened to go outside
|
||
the vector spaces, the values will be clipped accordingly.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item preset
|
||
Select one of the available color presets. This option can be used in addition
|
||
to the @option{r}, @option{g}, @option{b} parameters; in this case, the later
|
||
options takes priority on the preset values.
|
||
Available presets are:
|
||
@table @samp
|
||
@item none
|
||
@item color_negative
|
||
@item cross_process
|
||
@item darker
|
||
@item increase_contrast
|
||
@item lighter
|
||
@item linear_contrast
|
||
@item medium_contrast
|
||
@item negative
|
||
@item strong_contrast
|
||
@item vintage
|
||
@end table
|
||
Default is @code{none}.
|
||
@item master, m
|
||
Set the master key points. These points will define a second pass mapping. It
|
||
is sometimes called a "luminance" or "value" mapping. It can be used with
|
||
@option{r}, @option{g}, @option{b} or @option{all} since it acts like a
|
||
post-processing LUT.
|
||
@item red, r
|
||
Set the key points for the red component.
|
||
@item green, g
|
||
Set the key points for the green component.
|
||
@item blue, b
|
||
Set the key points for the blue component.
|
||
@item all
|
||
Set the key points for all components (not including master).
|
||
Can be used in addition to the other key points component
|
||
options. In this case, the unset component(s) will fallback on this
|
||
@option{all} setting.
|
||
@item psfile
|
||
Specify a Photoshop curves file (@code{.acv}) to import the settings from.
|
||
@item plot
|
||
Save Gnuplot script of the curves in specified file.
|
||
@end table
|
||
|
||
To avoid some filtergraph syntax conflicts, each key points list need to be
|
||
defined using the following syntax: @code{x0/y0 x1/y1 x2/y2 ...}.
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Increase slightly the middle level of blue:
|
||
@example
|
||
curves=blue='0/0 0.5/0.58 1/1'
|
||
@end example
|
||
|
||
@item
|
||
Vintage effect:
|
||
@example
|
||
curves=r='0/0.11 .42/.51 1/0.95':g='0/0 0.50/0.48 1/1':b='0/0.22 .49/.44 1/0.8'
|
||
@end example
|
||
Here we obtain the following coordinates for each components:
|
||
@table @var
|
||
@item red
|
||
@code{(0;0.11) (0.42;0.51) (1;0.95)}
|
||
@item green
|
||
@code{(0;0) (0.50;0.48) (1;1)}
|
||
@item blue
|
||
@code{(0;0.22) (0.49;0.44) (1;0.80)}
|
||
@end table
|
||
|
||
@item
|
||
The previous example can also be achieved with the associated built-in preset:
|
||
@example
|
||
curves=preset=vintage
|
||
@end example
|
||
|
||
@item
|
||
Or simply:
|
||
@example
|
||
curves=vintage
|
||
@end example
|
||
|
||
@item
|
||
Use a Photoshop preset and redefine the points of the green component:
|
||
@example
|
||
curves=psfile='MyCurvesPresets/purple.acv':green='0/0 0.45/0.53 1/1'
|
||
@end example
|
||
|
||
@item
|
||
Check out the curves of the @code{cross_process} profile using @command{ffmpeg}
|
||
and @command{gnuplot}:
|
||
@example
|
||
ffmpeg -f lavfi -i color -vf curves=cross_process:plot=/tmp/curves.plt -frames:v 1 -f null -
|
||
gnuplot -p /tmp/curves.plt
|
||
@end example
|
||
@end itemize
|
||
|
||
@section datascope
|
||
|
||
Video data analysis filter.
|
||
|
||
This filter shows hexadecimal pixel values of part of video.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item size, s
|
||
Set output video size.
|
||
|
||
@item x
|
||
Set x offset from where to pick pixels.
|
||
|
||
@item y
|
||
Set y offset from where to pick pixels.
|
||
|
||
@item mode
|
||
Set scope mode, can be one of the following:
|
||
@table @samp
|
||
@item mono
|
||
Draw hexadecimal pixel values with white color on black background.
|
||
|
||
@item color
|
||
Draw hexadecimal pixel values with input video pixel color on black
|
||
background.
|
||
|
||
@item color2
|
||
Draw hexadecimal pixel values on color background picked from input video,
|
||
the text color is picked in such way so its always visible.
|
||
@end table
|
||
|
||
@item axis
|
||
Draw rows and columns numbers on left and top of video.
|
||
|
||
@item opacity
|
||
Set background opacity.
|
||
@end table
|
||
|
||
@section dctdnoiz
|
||
|
||
Denoise frames using 2D DCT (frequency domain filtering).
|
||
|
||
This filter is not designed for real time.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item sigma, s
|
||
Set the noise sigma constant.
|
||
|
||
This @var{sigma} defines a hard threshold of @code{3 * sigma}; every DCT
|
||
coefficient (absolute value) below this threshold with be dropped.
|
||
|
||
If you need a more advanced filtering, see @option{expr}.
|
||
|
||
Default is @code{0}.
|
||
|
||
@item overlap
|
||
Set number overlapping pixels for each block. Since the filter can be slow, you
|
||
may want to reduce this value, at the cost of a less effective filter and the
|
||
risk of various artefacts.
|
||
|
||
If the overlapping value doesn't permit processing the whole input width or
|
||
height, a warning will be displayed and according borders won't be denoised.
|
||
|
||
Default value is @var{blocksize}-1, which is the best possible setting.
|
||
|
||
@item expr, e
|
||
Set the coefficient factor expression.
|
||
|
||
For each coefficient of a DCT block, this expression will be evaluated as a
|
||
multiplier value for the coefficient.
|
||
|
||
If this is option is set, the @option{sigma} option will be ignored.
|
||
|
||
The absolute value of the coefficient can be accessed through the @var{c}
|
||
variable.
|
||
|
||
@item n
|
||
Set the @var{blocksize} using the number of bits. @code{1<<@var{n}} defines the
|
||
@var{blocksize}, which is the width and height of the processed blocks.
|
||
|
||
The default value is @var{3} (8x8) and can be raised to @var{4} for a
|
||
@var{blocksize} of 16x16. Note that changing this setting has huge consequences
|
||
on the speed processing. Also, a larger block size does not necessarily means a
|
||
better de-noising.
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
Apply a denoise with a @option{sigma} of @code{4.5}:
|
||
@example
|
||
dctdnoiz=4.5
|
||
@end example
|
||
|
||
The same operation can be achieved using the expression system:
|
||
@example
|
||
dctdnoiz=e='gte(c, 4.5*3)'
|
||
@end example
|
||
|
||
Violent denoise using a block size of @code{16x16}:
|
||
@example
|
||
dctdnoiz=15:n=4
|
||
@end example
|
||
|
||
@section deband
|
||
|
||
Remove banding artifacts from input video.
|
||
It works by replacing banded pixels with average value of referenced pixels.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item 1thr
|
||
@item 2thr
|
||
@item 3thr
|
||
@item 4thr
|
||
Set banding detection threshold for each plane. Default is 0.02.
|
||
Valid range is 0.00003 to 0.5.
|
||
If difference between current pixel and reference pixel is less than threshold,
|
||
it will be considered as banded.
|
||
|
||
@item range, r
|
||
Banding detection range in pixels. Default is 16. If positive, random number
|
||
in range 0 to set value will be used. If negative, exact absolute value
|
||
will be used.
|
||
The range defines square of four pixels around current pixel.
|
||
|
||
@item direction, d
|
||
Set direction in radians from which four pixel will be compared. If positive,
|
||
random direction from 0 to set direction will be picked. If negative, exact of
|
||
absolute value will be picked. For example direction 0, -PI or -2*PI radians
|
||
will pick only pixels on same row and -PI/2 will pick only pixels on same
|
||
column.
|
||
|
||
@item blur, b
|
||
If enabled, current pixel is compared with average value of all four
|
||
surrounding pixels. The default is enabled. If disabled current pixel is
|
||
compared with all four surrounding pixels. The pixel is considered banded
|
||
if only all four differences with surrounding pixels are less than threshold.
|
||
|
||
@item coupling, c
|
||
If enabled, current pixel is changed if and only if all pixel components are banded,
|
||
e.g. banding detection threshold is triggered for all color components.
|
||
The default is disabled.
|
||
@end table
|
||
|
||
@anchor{decimate}
|
||
@section decimate
|
||
|
||
Drop duplicated frames at regular intervals.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item cycle
|
||
Set the number of frames from which one will be dropped. Setting this to
|
||
@var{N} means one frame in every batch of @var{N} frames will be dropped.
|
||
Default is @code{5}.
|
||
|
||
@item dupthresh
|
||
Set the threshold for duplicate detection. If the difference metric for a frame
|
||
is less than or equal to this value, then it is declared as duplicate. Default
|
||
is @code{1.1}
|
||
|
||
@item scthresh
|
||
Set scene change threshold. Default is @code{15}.
|
||
|
||
@item blockx
|
||
@item blocky
|
||
Set the size of the x and y-axis blocks used during metric calculations.
|
||
Larger blocks give better noise suppression, but also give worse detection of
|
||
small movements. Must be a power of two. Default is @code{32}.
|
||
|
||
@item ppsrc
|
||
Mark main input as a pre-processed input and activate clean source input
|
||
stream. This allows the input to be pre-processed with various filters to help
|
||
the metrics calculation while keeping the frame selection lossless. When set to
|
||
@code{1}, the first stream is for the pre-processed input, and the second
|
||
stream is the clean source from where the kept frames are chosen. Default is
|
||
@code{0}.
|
||
|
||
@item chroma
|
||
Set whether or not chroma is considered in the metric calculations. Default is
|
||
@code{1}.
|
||
@end table
|
||
|
||
@section deflate
|
||
|
||
Apply deflate effect to the video.
|
||
|
||
This filter replaces the pixel by the local(3x3) average by taking into account
|
||
only values lower than the pixel.
|
||
|
||
It accepts the following options:
|
||
|
||
@table @option
|
||
@item threshold0
|
||
@item threshold1
|
||
@item threshold2
|
||
@item threshold3
|
||
Limit the maximum change for each plane, default is 65535.
|
||
If 0, plane will remain unchanged.
|
||
@end table
|
||
|
||
@section deflicker
|
||
|
||
Remove temporal frame luminance variations.
|
||
|
||
It accepts the following options:
|
||
|
||
@table @option
|
||
@item size, s
|
||
Set moving-average filter size in frames. Default is 5. Allowed range is 2 - 129.
|
||
|
||
@item mode, m
|
||
Set averaging mode to smooth temporal luminance variations.
|
||
|
||
Available values are:
|
||
@table @samp
|
||
@item am
|
||
Arithmetic mean
|
||
|
||
@item gm
|
||
Geometric mean
|
||
|
||
@item hm
|
||
Harmonic mean
|
||
|
||
@item qm
|
||
Quadratic mean
|
||
|
||
@item cm
|
||
Cubic mean
|
||
|
||
@item pm
|
||
Power mean
|
||
|
||
@item median
|
||
Median
|
||
@end table
|
||
|
||
@item bypass
|
||
Do not actually modify frame. Useful when one only wants metadata.
|
||
@end table
|
||
|
||
@section dejudder
|
||
|
||
Remove judder produced by partially interlaced telecined content.
|
||
|
||
Judder can be introduced, for instance, by @ref{pullup} filter. If the original
|
||
source was partially telecined content then the output of @code{pullup,dejudder}
|
||
will have a variable frame rate. May change the recorded frame rate of the
|
||
container. Aside from that change, this filter will not affect constant frame
|
||
rate video.
|
||
|
||
The option available in this filter is:
|
||
@table @option
|
||
|
||
@item cycle
|
||
Specify the length of the window over which the judder repeats.
|
||
|
||
Accepts any integer greater than 1. Useful values are:
|
||
@table @samp
|
||
|
||
@item 4
|
||
If the original was telecined from 24 to 30 fps (Film to NTSC).
|
||
|
||
@item 5
|
||
If the original was telecined from 25 to 30 fps (PAL to NTSC).
|
||
|
||
@item 20
|
||
If a mixture of the two.
|
||
@end table
|
||
|
||
The default is @samp{4}.
|
||
@end table
|
||
|
||
@section delogo
|
||
|
||
Suppress a TV station logo by a simple interpolation of the surrounding
|
||
pixels. Just set a rectangle covering the logo and watch it disappear
|
||
(and sometimes something even uglier appear - your mileage may vary).
|
||
|
||
It accepts the following parameters:
|
||
@table @option
|
||
|
||
@item x
|
||
@item y
|
||
Specify the top left corner coordinates of the logo. They must be
|
||
specified.
|
||
|
||
@item w
|
||
@item h
|
||
Specify the width and height of the logo to clear. They must be
|
||
specified.
|
||
|
||
@item band, t
|
||
Specify the thickness of the fuzzy edge of the rectangle (added to
|
||
@var{w} and @var{h}). The default value is 1. This option is
|
||
deprecated, setting higher values should no longer be necessary and
|
||
is not recommended.
|
||
|
||
@item show
|
||
When set to 1, a green rectangle is drawn on the screen to simplify
|
||
finding the right @var{x}, @var{y}, @var{w}, and @var{h} parameters.
|
||
The default value is 0.
|
||
|
||
The rectangle is drawn on the outermost pixels which will be (partly)
|
||
replaced with interpolated values. The values of the next pixels
|
||
immediately outside this rectangle in each direction will be used to
|
||
compute the interpolated pixel values inside the rectangle.
|
||
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Set a rectangle covering the area with top left corner coordinates 0,0
|
||
and size 100x77, and a band of size 10:
|
||
@example
|
||
delogo=x=0:y=0:w=100:h=77:band=10
|
||
@end example
|
||
|
||
@end itemize
|
||
|
||
@section deshake
|
||
|
||
Attempt to fix small changes in horizontal and/or vertical shift. This
|
||
filter helps remove camera shake from hand-holding a camera, bumping a
|
||
tripod, moving on a vehicle, etc.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
|
||
@item x
|
||
@item y
|
||
@item w
|
||
@item h
|
||
Specify a rectangular area where to limit the search for motion
|
||
vectors.
|
||
If desired the search for motion vectors can be limited to a
|
||
rectangular area of the frame defined by its top left corner, width
|
||
and height. These parameters have the same meaning as the drawbox
|
||
filter which can be used to visualise the position of the bounding
|
||
box.
|
||
|
||
This is useful when simultaneous movement of subjects within the frame
|
||
might be confused for camera motion by the motion vector search.
|
||
|
||
If any or all of @var{x}, @var{y}, @var{w} and @var{h} are set to -1
|
||
then the full frame is used. This allows later options to be set
|
||
without specifying the bounding box for the motion vector search.
|
||
|
||
Default - search the whole frame.
|
||
|
||
@item rx
|
||
@item ry
|
||
Specify the maximum extent of movement in x and y directions in the
|
||
range 0-64 pixels. Default 16.
|
||
|
||
@item edge
|
||
Specify how to generate pixels to fill blanks at the edge of the
|
||
frame. Available values are:
|
||
@table @samp
|
||
@item blank, 0
|
||
Fill zeroes at blank locations
|
||
@item original, 1
|
||
Original image at blank locations
|
||
@item clamp, 2
|
||
Extruded edge value at blank locations
|
||
@item mirror, 3
|
||
Mirrored edge at blank locations
|
||
@end table
|
||
Default value is @samp{mirror}.
|
||
|
||
@item blocksize
|
||
Specify the blocksize to use for motion search. Range 4-128 pixels,
|
||
default 8.
|
||
|
||
@item contrast
|
||
Specify the contrast threshold for blocks. Only blocks with more than
|
||
the specified contrast (difference between darkest and lightest
|
||
pixels) will be considered. Range 1-255, default 125.
|
||
|
||
@item search
|
||
Specify the search strategy. Available values are:
|
||
@table @samp
|
||
@item exhaustive, 0
|
||
Set exhaustive search
|
||
@item less, 1
|
||
Set less exhaustive search.
|
||
@end table
|
||
Default value is @samp{exhaustive}.
|
||
|
||
@item filename
|
||
If set then a detailed log of the motion search is written to the
|
||
specified file.
|
||
|
||
@item opencl
|
||
If set to 1, specify using OpenCL capabilities, only available if
|
||
FFmpeg was configured with @code{--enable-opencl}. Default value is 0.
|
||
|
||
@end table
|
||
|
||
@section detelecine
|
||
|
||
Apply an exact inverse of the telecine operation. It requires a predefined
|
||
pattern specified using the pattern option which must be the same as that passed
|
||
to the telecine filter.
|
||
|
||
This filter accepts the following options:
|
||
|
||
@table @option
|
||
@item first_field
|
||
@table @samp
|
||
@item top, t
|
||
top field first
|
||
@item bottom, b
|
||
bottom field first
|
||
The default value is @code{top}.
|
||
@end table
|
||
|
||
@item pattern
|
||
A string of numbers representing the pulldown pattern you wish to apply.
|
||
The default value is @code{23}.
|
||
|
||
@item start_frame
|
||
A number representing position of the first frame with respect to the telecine
|
||
pattern. This is to be used if the stream is cut. The default value is @code{0}.
|
||
@end table
|
||
|
||
@section dilation
|
||
|
||
Apply dilation effect to the video.
|
||
|
||
This filter replaces the pixel by the local(3x3) maximum.
|
||
|
||
It accepts the following options:
|
||
|
||
@table @option
|
||
@item threshold0
|
||
@item threshold1
|
||
@item threshold2
|
||
@item threshold3
|
||
Limit the maximum change for each plane, default is 65535.
|
||
If 0, plane will remain unchanged.
|
||
|
||
@item coordinates
|
||
Flag which specifies the pixel to refer to. Default is 255 i.e. all eight
|
||
pixels are used.
|
||
|
||
Flags to local 3x3 coordinates maps like this:
|
||
|
||
1 2 3
|
||
4 5
|
||
6 7 8
|
||
@end table
|
||
|
||
@section displace
|
||
|
||
Displace pixels as indicated by second and third input stream.
|
||
|
||
It takes three input streams and outputs one stream, the first input is the
|
||
source, and second and third input are displacement maps.
|
||
|
||
The second input specifies how much to displace pixels along the
|
||
x-axis, while the third input specifies how much to displace pixels
|
||
along the y-axis.
|
||
If one of displacement map streams terminates, last frame from that
|
||
displacement map will be used.
|
||
|
||
Note that once generated, displacements maps can be reused over and over again.
|
||
|
||
A description of the accepted options follows.
|
||
|
||
@table @option
|
||
@item edge
|
||
Set displace behavior for pixels that are out of range.
|
||
|
||
Available values are:
|
||
@table @samp
|
||
@item blank
|
||
Missing pixels are replaced by black pixels.
|
||
|
||
@item smear
|
||
Adjacent pixels will spread out to replace missing pixels.
|
||
|
||
@item wrap
|
||
Out of range pixels are wrapped so they point to pixels of other side.
|
||
@end table
|
||
Default is @samp{smear}.
|
||
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Add ripple effect to rgb input of video size hd720:
|
||
@example
|
||
ffmpeg -i INPUT -f lavfi -i nullsrc=s=hd720,lutrgb=128:128:128 -f lavfi -i nullsrc=s=hd720,geq='r=128+30*sin(2*PI*X/400+T):g=128+30*sin(2*PI*X/400+T):b=128+30*sin(2*PI*X/400+T)' -lavfi '[0][1][2]displace' OUTPUT
|
||
@end example
|
||
|
||
@item
|
||
Add wave effect to rgb input of video size hd720:
|
||
@example
|
||
ffmpeg -i INPUT -f lavfi -i nullsrc=hd720,geq='r=128+80*(sin(sqrt((X-W/2)*(X-W/2)+(Y-H/2)*(Y-H/2))/220*2*PI+T)):g=128+80*(sin(sqrt((X-W/2)*(X-W/2)+(Y-H/2)*(Y-H/2))/220*2*PI+T)):b=128+80*(sin(sqrt((X-W/2)*(X-W/2)+(Y-H/2)*(Y-H/2))/220*2*PI+T))' -lavfi '[1]split[x][y],[0][x][y]displace' OUTPUT
|
||
@end example
|
||
@end itemize
|
||
|
||
@section drawbox
|
||
|
||
Draw a colored box on the input image.
|
||
|
||
It accepts the following parameters:
|
||
|
||
@table @option
|
||
@item x
|
||
@item y
|
||
The expressions which specify the top left corner coordinates of the box. It defaults to 0.
|
||
|
||
@item width, w
|
||
@item height, h
|
||
The expressions which specify the width and height of the box; if 0 they are interpreted as
|
||
the input width and height. It defaults to 0.
|
||
|
||
@item color, c
|
||
Specify the color of the box to write. For the general syntax of this option,
|
||
check the "Color" section in the ffmpeg-utils manual. If the special
|
||
value @code{invert} is used, the box edge color is the same as the
|
||
video with inverted luma.
|
||
|
||
@item thickness, t
|
||
The expression which sets the thickness of the box edge. Default value is @code{3}.
|
||
|
||
See below for the list of accepted constants.
|
||
@end table
|
||
|
||
The parameters for @var{x}, @var{y}, @var{w} and @var{h} and @var{t} are expressions containing the
|
||
following constants:
|
||
|
||
@table @option
|
||
@item dar
|
||
The input display aspect ratio, it is the same as (@var{w} / @var{h}) * @var{sar}.
|
||
|
||
@item hsub
|
||
@item vsub
|
||
horizontal and vertical chroma subsample values. For example for the
|
||
pixel format "yuv422p" @var{hsub} is 2 and @var{vsub} is 1.
|
||
|
||
@item in_h, ih
|
||
@item in_w, iw
|
||
The input width and height.
|
||
|
||
@item sar
|
||
The input sample aspect ratio.
|
||
|
||
@item x
|
||
@item y
|
||
The x and y offset coordinates where the box is drawn.
|
||
|
||
@item w
|
||
@item h
|
||
The width and height of the drawn box.
|
||
|
||
@item t
|
||
The thickness of the drawn box.
|
||
|
||
These constants allow the @var{x}, @var{y}, @var{w}, @var{h} and @var{t} expressions to refer to
|
||
each other, so you may for example specify @code{y=x/dar} or @code{h=w/dar}.
|
||
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Draw a black box around the edge of the input image:
|
||
@example
|
||
drawbox
|
||
@end example
|
||
|
||
@item
|
||
Draw a box with color red and an opacity of 50%:
|
||
@example
|
||
drawbox=10:20:200:60:red@@0.5
|
||
@end example
|
||
|
||
The previous example can be specified as:
|
||
@example
|
||
drawbox=x=10:y=20:w=200:h=60:color=red@@0.5
|
||
@end example
|
||
|
||
@item
|
||
Fill the box with pink color:
|
||
@example
|
||
drawbox=x=10:y=10:w=100:h=100:color=pink@@0.5:t=max
|
||
@end example
|
||
|
||
@item
|
||
Draw a 2-pixel red 2.40:1 mask:
|
||
@example
|
||
drawbox=x=-t:y=0.5*(ih-iw/2.4)-t:w=iw+t*2:h=iw/2.4+t*2:t=2:c=red
|
||
@end example
|
||
@end itemize
|
||
|
||
@section drawgrid
|
||
|
||
Draw a grid on the input image.
|
||
|
||
It accepts the following parameters:
|
||
|
||
@table @option
|
||
@item x
|
||
@item y
|
||
The expressions which specify the coordinates of some point of grid intersection (meant to configure offset). Both default to 0.
|
||
|
||
@item width, w
|
||
@item height, h
|
||
The expressions which specify the width and height of the grid cell, if 0 they are interpreted as the
|
||
input width and height, respectively, minus @code{thickness}, so image gets
|
||
framed. Default to 0.
|
||
|
||
@item color, c
|
||
Specify the color of the grid. For the general syntax of this option,
|
||
check the "Color" section in the ffmpeg-utils manual. If the special
|
||
value @code{invert} is used, the grid color is the same as the
|
||
video with inverted luma.
|
||
|
||
@item thickness, t
|
||
The expression which sets the thickness of the grid line. Default value is @code{1}.
|
||
|
||
See below for the list of accepted constants.
|
||
@end table
|
||
|
||
The parameters for @var{x}, @var{y}, @var{w} and @var{h} and @var{t} are expressions containing the
|
||
following constants:
|
||
|
||
@table @option
|
||
@item dar
|
||
The input display aspect ratio, it is the same as (@var{w} / @var{h}) * @var{sar}.
|
||
|
||
@item hsub
|
||
@item vsub
|
||
horizontal and vertical chroma subsample values. For example for the
|
||
pixel format "yuv422p" @var{hsub} is 2 and @var{vsub} is 1.
|
||
|
||
@item in_h, ih
|
||
@item in_w, iw
|
||
The input grid cell width and height.
|
||
|
||
@item sar
|
||
The input sample aspect ratio.
|
||
|
||
@item x
|
||
@item y
|
||
The x and y coordinates of some point of grid intersection (meant to configure offset).
|
||
|
||
@item w
|
||
@item h
|
||
The width and height of the drawn cell.
|
||
|
||
@item t
|
||
The thickness of the drawn cell.
|
||
|
||
These constants allow the @var{x}, @var{y}, @var{w}, @var{h} and @var{t} expressions to refer to
|
||
each other, so you may for example specify @code{y=x/dar} or @code{h=w/dar}.
|
||
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Draw a grid with cell 100x100 pixels, thickness 2 pixels, with color red and an opacity of 50%:
|
||
@example
|
||
drawgrid=width=100:height=100:thickness=2:color=red@@0.5
|
||
@end example
|
||
|
||
@item
|
||
Draw a white 3x3 grid with an opacity of 50%:
|
||
@example
|
||
drawgrid=w=iw/3:h=ih/3:t=2:c=white@@0.5
|
||
@end example
|
||
@end itemize
|
||
|
||
@anchor{drawtext}
|
||
@section drawtext
|
||
|
||
Draw a text string or text from a specified file on top of a video, using the
|
||
libfreetype library.
|
||
|
||
To enable compilation of this filter, you need to configure FFmpeg with
|
||
@code{--enable-libfreetype}.
|
||
To enable default font fallback and the @var{font} option you need to
|
||
configure FFmpeg with @code{--enable-libfontconfig}.
|
||
To enable the @var{text_shaping} option, you need to configure FFmpeg with
|
||
@code{--enable-libfribidi}.
|
||
|
||
@subsection Syntax
|
||
|
||
It accepts the following parameters:
|
||
|
||
@table @option
|
||
|
||
@item box
|
||
Used to draw a box around text using the background color.
|
||
The value must be either 1 (enable) or 0 (disable).
|
||
The default value of @var{box} is 0.
|
||
|
||
@item boxborderw
|
||
Set the width of the border to be drawn around the box using @var{boxcolor}.
|
||
The default value of @var{boxborderw} is 0.
|
||
|
||
@item boxcolor
|
||
The color to be used for drawing box around text. For the syntax of this
|
||
option, check the "Color" section in the ffmpeg-utils manual.
|
||
|
||
The default value of @var{boxcolor} is "white".
|
||
|
||
@item line_spacing
|
||
Set the line spacing in pixels of the border to be drawn around the box using @var{box}.
|
||
The default value of @var{line_spacing} is 0.
|
||
|
||
@item borderw
|
||
Set the width of the border to be drawn around the text using @var{bordercolor}.
|
||
The default value of @var{borderw} is 0.
|
||
|
||
@item bordercolor
|
||
Set the color to be used for drawing border around text. For the syntax of this
|
||
option, check the "Color" section in the ffmpeg-utils manual.
|
||
|
||
The default value of @var{bordercolor} is "black".
|
||
|
||
@item expansion
|
||
Select how the @var{text} is expanded. Can be either @code{none},
|
||
@code{strftime} (deprecated) or
|
||
@code{normal} (default). See the @ref{drawtext_expansion, Text expansion} section
|
||
below for details.
|
||
|
||
@item basetime
|
||
Set a start time for the count. Value is in microseconds. Only applied
|
||
in the deprecated strftime expansion mode. To emulate in normal expansion
|
||
mode use the @code{pts} function, supplying the start time (in seconds)
|
||
as the second argument.
|
||
|
||
@item fix_bounds
|
||
If true, check and fix text coords to avoid clipping.
|
||
|
||
@item fontcolor
|
||
The color to be used for drawing fonts. For the syntax of this option, check
|
||
the "Color" section in the ffmpeg-utils manual.
|
||
|
||
The default value of @var{fontcolor} is "black".
|
||
|
||
@item fontcolor_expr
|
||
String which is expanded the same way as @var{text} to obtain dynamic
|
||
@var{fontcolor} value. By default this option has empty value and is not
|
||
processed. When this option is set, it overrides @var{fontcolor} option.
|
||
|
||
@item font
|
||
The font family to be used for drawing text. By default Sans.
|
||
|
||
@item fontfile
|
||
The font file to be used for drawing text. The path must be included.
|
||
This parameter is mandatory if the fontconfig support is disabled.
|
||
|
||
@item alpha
|
||
Draw the text applying alpha blending. The value can
|
||
be a number between 0.0 and 1.0.
|
||
The expression accepts the same variables @var{x, y} as well.
|
||
The default value is 1.
|
||
Please see @var{fontcolor_expr}.
|
||
|
||
@item fontsize
|
||
The font size to be used for drawing text.
|
||
The default value of @var{fontsize} is 16.
|
||
|
||
@item text_shaping
|
||
If set to 1, attempt to shape the text (for example, reverse the order of
|
||
right-to-left text and join Arabic characters) before drawing it.
|
||
Otherwise, just draw the text exactly as given.
|
||
By default 1 (if supported).
|
||
|
||
@item ft_load_flags
|
||
The flags to be used for loading the fonts.
|
||
|
||
The flags map the corresponding flags supported by libfreetype, and are
|
||
a combination of the following values:
|
||
@table @var
|
||
@item default
|
||
@item no_scale
|
||
@item no_hinting
|
||
@item render
|
||
@item no_bitmap
|
||
@item vertical_layout
|
||
@item force_autohint
|
||
@item crop_bitmap
|
||
@item pedantic
|
||
@item ignore_global_advance_width
|
||
@item no_recurse
|
||
@item ignore_transform
|
||
@item monochrome
|
||
@item linear_design
|
||
@item no_autohint
|
||
@end table
|
||
|
||
Default value is "default".
|
||
|
||
For more information consult the documentation for the FT_LOAD_*
|
||
libfreetype flags.
|
||
|
||
@item shadowcolor
|
||
The color to be used for drawing a shadow behind the drawn text. For the
|
||
syntax of this option, check the "Color" section in the ffmpeg-utils manual.
|
||
|
||
The default value of @var{shadowcolor} is "black".
|
||
|
||
@item shadowx
|
||
@item shadowy
|
||
The x and y offsets for the text shadow position with respect to the
|
||
position of the text. They can be either positive or negative
|
||
values. The default value for both is "0".
|
||
|
||
@item start_number
|
||
The starting frame number for the n/frame_num variable. The default value
|
||
is "0".
|
||
|
||
@item tabsize
|
||
The size in number of spaces to use for rendering the tab.
|
||
Default value is 4.
|
||
|
||
@item timecode
|
||
Set the initial timecode representation in "hh:mm:ss[:;.]ff"
|
||
format. It can be used with or without text parameter. @var{timecode_rate}
|
||
option must be specified.
|
||
|
||
@item timecode_rate, rate, r
|
||
Set the timecode frame rate (timecode only).
|
||
|
||
@item tc24hmax
|
||
If set to 1, the output of the timecode option will wrap around at 24 hours.
|
||
Default is 0 (disabled).
|
||
|
||
@item text
|
||
The text string to be drawn. The text must be a sequence of UTF-8
|
||
encoded characters.
|
||
This parameter is mandatory if no file is specified with the parameter
|
||
@var{textfile}.
|
||
|
||
@item textfile
|
||
A text file containing text to be drawn. The text must be a sequence
|
||
of UTF-8 encoded characters.
|
||
|
||
This parameter is mandatory if no text string is specified with the
|
||
parameter @var{text}.
|
||
|
||
If both @var{text} and @var{textfile} are specified, an error is thrown.
|
||
|
||
@item reload
|
||
If set to 1, the @var{textfile} will be reloaded before each frame.
|
||
Be sure to update it atomically, or it may be read partially, or even fail.
|
||
|
||
@item x
|
||
@item y
|
||
The expressions which specify the offsets where text will be drawn
|
||
within the video frame. They are relative to the top/left border of the
|
||
output image.
|
||
|
||
The default value of @var{x} and @var{y} is "0".
|
||
|
||
See below for the list of accepted constants and functions.
|
||
@end table
|
||
|
||
The parameters for @var{x} and @var{y} are expressions containing the
|
||
following constants and functions:
|
||
|
||
@table @option
|
||
@item dar
|
||
input display aspect ratio, it is the same as (@var{w} / @var{h}) * @var{sar}
|
||
|
||
@item hsub
|
||
@item vsub
|
||
horizontal and vertical chroma subsample values. For example for the
|
||
pixel format "yuv422p" @var{hsub} is 2 and @var{vsub} is 1.
|
||
|
||
@item line_h, lh
|
||
the height of each text line
|
||
|
||
@item main_h, h, H
|
||
the input height
|
||
|
||
@item main_w, w, W
|
||
the input width
|
||
|
||
@item max_glyph_a, ascent
|
||
the maximum distance from the baseline to the highest/upper grid
|
||
coordinate used to place a glyph outline point, for all the rendered
|
||
glyphs.
|
||
It is a positive value, due to the grid's orientation with the Y axis
|
||
upwards.
|
||
|
||
@item max_glyph_d, descent
|
||
the maximum distance from the baseline to the lowest grid coordinate
|
||
used to place a glyph outline point, for all the rendered glyphs.
|
||
This is a negative value, due to the grid's orientation, with the Y axis
|
||
upwards.
|
||
|
||
@item max_glyph_h
|
||
maximum glyph height, that is the maximum height for all the glyphs
|
||
contained in the rendered text, it is equivalent to @var{ascent} -
|
||
@var{descent}.
|
||
|
||
@item max_glyph_w
|
||
maximum glyph width, that is the maximum width for all the glyphs
|
||
contained in the rendered text
|
||
|
||
@item n
|
||
the number of input frame, starting from 0
|
||
|
||
@item rand(min, max)
|
||
return a random number included between @var{min} and @var{max}
|
||
|
||
@item sar
|
||
The input sample aspect ratio.
|
||
|
||
@item t
|
||
timestamp expressed in seconds, NAN if the input timestamp is unknown
|
||
|
||
@item text_h, th
|
||
the height of the rendered text
|
||
|
||
@item text_w, tw
|
||
the width of the rendered text
|
||
|
||
@item x
|
||
@item y
|
||
the x and y offset coordinates where the text is drawn.
|
||
|
||
These parameters allow the @var{x} and @var{y} expressions to refer
|
||
each other, so you can for example specify @code{y=x/dar}.
|
||
@end table
|
||
|
||
@anchor{drawtext_expansion}
|
||
@subsection Text expansion
|
||
|
||
If @option{expansion} is set to @code{strftime},
|
||
the filter recognizes strftime() sequences in the provided text and
|
||
expands them accordingly. Check the documentation of strftime(). This
|
||
feature is deprecated.
|
||
|
||
If @option{expansion} is set to @code{none}, the text is printed verbatim.
|
||
|
||
If @option{expansion} is set to @code{normal} (which is the default),
|
||
the following expansion mechanism is used.
|
||
|
||
The backslash character @samp{\}, followed by any character, always expands to
|
||
the second character.
|
||
|
||
Sequences of the form @code{%@{...@}} are expanded. The text between the
|
||
braces is a function name, possibly followed by arguments separated by ':'.
|
||
If the arguments contain special characters or delimiters (':' or '@}'),
|
||
they should be escaped.
|
||
|
||
Note that they probably must also be escaped as the value for the
|
||
@option{text} option in the filter argument string and as the filter
|
||
argument in the filtergraph description, and possibly also for the shell,
|
||
that makes up to four levels of escaping; using a text file avoids these
|
||
problems.
|
||
|
||
The following functions are available:
|
||
|
||
@table @command
|
||
|
||
@item expr, e
|
||
The expression evaluation result.
|
||
|
||
It must take one argument specifying the expression to be evaluated,
|
||
which accepts the same constants and functions as the @var{x} and
|
||
@var{y} values. Note that not all constants should be used, for
|
||
example the text size is not known when evaluating the expression, so
|
||
the constants @var{text_w} and @var{text_h} will have an undefined
|
||
value.
|
||
|
||
@item expr_int_format, eif
|
||
Evaluate the expression's value and output as formatted integer.
|
||
|
||
The first argument is the expression to be evaluated, just as for the @var{expr} function.
|
||
The second argument specifies the output format. Allowed values are @samp{x},
|
||
@samp{X}, @samp{d} and @samp{u}. They are treated exactly as in the
|
||
@code{printf} function.
|
||
The third parameter is optional and sets the number of positions taken by the output.
|
||
It can be used to add padding with zeros from the left.
|
||
|
||
@item gmtime
|
||
The time at which the filter is running, expressed in UTC.
|
||
It can accept an argument: a strftime() format string.
|
||
|
||
@item localtime
|
||
The time at which the filter is running, expressed in the local time zone.
|
||
It can accept an argument: a strftime() format string.
|
||
|
||
@item metadata
|
||
Frame metadata. Takes one or two arguments.
|
||
|
||
The first argument is mandatory and specifies the metadata key.
|
||
|
||
The second argument is optional and specifies a default value, used when the
|
||
metadata key is not found or empty.
|
||
|
||
@item n, frame_num
|
||
The frame number, starting from 0.
|
||
|
||
@item pict_type
|
||
A 1 character description of the current picture type.
|
||
|
||
@item pts
|
||
The timestamp of the current frame.
|
||
It can take up to three arguments.
|
||
|
||
The first argument is the format of the timestamp; it defaults to @code{flt}
|
||
for seconds as a decimal number with microsecond accuracy; @code{hms} stands
|
||
for a formatted @var{[-]HH:MM:SS.mmm} timestamp with millisecond accuracy.
|
||
@code{gmtime} stands for the timestamp of the frame formatted as UTC time;
|
||
@code{localtime} stands for the timestamp of the frame formatted as
|
||
local time zone time.
|
||
|
||
The second argument is an offset added to the timestamp.
|
||
|
||
If the format is set to @code{localtime} or @code{gmtime},
|
||
a third argument may be supplied: a strftime() format string.
|
||
By default, @var{YYYY-MM-DD HH:MM:SS} format will be used.
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Draw "Test Text" with font FreeSerif, using the default values for the
|
||
optional parameters.
|
||
|
||
@example
|
||
drawtext="fontfile=/usr/share/fonts/truetype/freefont/FreeSerif.ttf: text='Test Text'"
|
||
@end example
|
||
|
||
@item
|
||
Draw 'Test Text' with font FreeSerif of size 24 at position x=100
|
||
and y=50 (counting from the top-left corner of the screen), text is
|
||
yellow with a red box around it. Both the text and the box have an
|
||
opacity of 20%.
|
||
|
||
@example
|
||
drawtext="fontfile=/usr/share/fonts/truetype/freefont/FreeSerif.ttf: text='Test Text':\
|
||
x=100: y=50: fontsize=24: fontcolor=yellow@@0.2: box=1: boxcolor=red@@0.2"
|
||
@end example
|
||
|
||
Note that the double quotes are not necessary if spaces are not used
|
||
within the parameter list.
|
||
|
||
@item
|
||
Show the text at the center of the video frame:
|
||
@example
|
||
drawtext="fontsize=30:fontfile=FreeSerif.ttf:text='hello world':x=(w-text_w)/2:y=(h-text_h)/2"
|
||
@end example
|
||
|
||
@item
|
||
Show the text at a random position, switching to a new position every 30 seconds:
|
||
@example
|
||
drawtext="fontsize=30:fontfile=FreeSerif.ttf:text='hello world':x=if(eq(mod(t\,30)\,0)\,rand(0\,(w-text_w))\,x):y=if(eq(mod(t\,30)\,0)\,rand(0\,(h-text_h))\,y)"
|
||
@end example
|
||
|
||
@item
|
||
Show a text line sliding from right to left in the last row of the video
|
||
frame. The file @file{LONG_LINE} is assumed to contain a single line
|
||
with no newlines.
|
||
@example
|
||
drawtext="fontsize=15:fontfile=FreeSerif.ttf:text=LONG_LINE:y=h-line_h:x=-50*t"
|
||
@end example
|
||
|
||
@item
|
||
Show the content of file @file{CREDITS} off the bottom of the frame and scroll up.
|
||
@example
|
||
drawtext="fontsize=20:fontfile=FreeSerif.ttf:textfile=CREDITS:y=h-20*t"
|
||
@end example
|
||
|
||
@item
|
||
Draw a single green letter "g", at the center of the input video.
|
||
The glyph baseline is placed at half screen height.
|
||
@example
|
||
drawtext="fontsize=60:fontfile=FreeSerif.ttf:fontcolor=green:text=g:x=(w-max_glyph_w)/2:y=h/2-ascent"
|
||
@end example
|
||
|
||
@item
|
||
Show text for 1 second every 3 seconds:
|
||
@example
|
||
drawtext="fontfile=FreeSerif.ttf:fontcolor=white:x=100:y=x/dar:enable=lt(mod(t\,3)\,1):text='blink'"
|
||
@end example
|
||
|
||
@item
|
||
Use fontconfig to set the font. Note that the colons need to be escaped.
|
||
@example
|
||
drawtext='fontfile=Linux Libertine O-40\:style=Semibold:text=FFmpeg'
|
||
@end example
|
||
|
||
@item
|
||
Print the date of a real-time encoding (see strftime(3)):
|
||
@example
|
||
drawtext='fontfile=FreeSans.ttf:text=%@{localtime\:%a %b %d %Y@}'
|
||
@end example
|
||
|
||
@item
|
||
Show text fading in and out (appearing/disappearing):
|
||
@example
|
||
#!/bin/sh
|
||
DS=1.0 # display start
|
||
DE=10.0 # display end
|
||
FID=1.5 # fade in duration
|
||
FOD=5 # fade out duration
|
||
ffplay -f lavfi "color,drawtext=text=TEST:fontsize=50:fontfile=FreeSerif.ttf:fontcolor_expr=ff0000%@{eif\\\\: clip(255*(1*between(t\\, $DS + $FID\\, $DE - $FOD) + ((t - $DS)/$FID)*between(t\\, $DS\\, $DS + $FID) + (-(t - $DE)/$FOD)*between(t\\, $DE - $FOD\\, $DE) )\\, 0\\, 255) \\\\: x\\\\: 2 @}"
|
||
@end example
|
||
|
||
@item
|
||
Horizontally align multiple separate texts. Note that @option{max_glyph_a}
|
||
and the @option{fontsize} value are included in the @option{y} offset.
|
||
@example
|
||
drawtext=fontfile=FreeSans.ttf:text=DOG:fontsize=24:x=10:y=20+24-max_glyph_a,
|
||
drawtext=fontfile=FreeSans.ttf:text=cow:fontsize=24:x=80:y=20+24-max_glyph_a
|
||
@end example
|
||
|
||
@end itemize
|
||
|
||
For more information about libfreetype, check:
|
||
@url{http://www.freetype.org/}.
|
||
|
||
For more information about fontconfig, check:
|
||
@url{http://freedesktop.org/software/fontconfig/fontconfig-user.html}.
|
||
|
||
For more information about libfribidi, check:
|
||
@url{http://fribidi.org/}.
|
||
|
||
@section edgedetect
|
||
|
||
Detect and draw edges. The filter uses the Canny Edge Detection algorithm.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item low
|
||
@item high
|
||
Set low and high threshold values used by the Canny thresholding
|
||
algorithm.
|
||
|
||
The high threshold selects the "strong" edge pixels, which are then
|
||
connected through 8-connectivity with the "weak" edge pixels selected
|
||
by the low threshold.
|
||
|
||
@var{low} and @var{high} threshold values must be chosen in the range
|
||
[0,1], and @var{low} should be lesser or equal to @var{high}.
|
||
|
||
Default value for @var{low} is @code{20/255}, and default value for @var{high}
|
||
is @code{50/255}.
|
||
|
||
@item mode
|
||
Define the drawing mode.
|
||
|
||
@table @samp
|
||
@item wires
|
||
Draw white/gray wires on black background.
|
||
|
||
@item colormix
|
||
Mix the colors to create a paint/cartoon effect.
|
||
@end table
|
||
|
||
Default value is @var{wires}.
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Standard edge detection with custom values for the hysteresis thresholding:
|
||
@example
|
||
edgedetect=low=0.1:high=0.4
|
||
@end example
|
||
|
||
@item
|
||
Painting effect without thresholding:
|
||
@example
|
||
edgedetect=mode=colormix:high=0
|
||
@end example
|
||
@end itemize
|
||
|
||
@section eq
|
||
Set brightness, contrast, saturation and approximate gamma adjustment.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item contrast
|
||
Set the contrast expression. The value must be a float value in range
|
||
@code{-2.0} to @code{2.0}. The default value is "1".
|
||
|
||
@item brightness
|
||
Set the brightness expression. The value must be a float value in
|
||
range @code{-1.0} to @code{1.0}. The default value is "0".
|
||
|
||
@item saturation
|
||
Set the saturation expression. The value must be a float in
|
||
range @code{0.0} to @code{3.0}. The default value is "1".
|
||
|
||
@item gamma
|
||
Set the gamma expression. The value must be a float in range
|
||
@code{0.1} to @code{10.0}. The default value is "1".
|
||
|
||
@item gamma_r
|
||
Set the gamma expression for red. The value must be a float in
|
||
range @code{0.1} to @code{10.0}. The default value is "1".
|
||
|
||
@item gamma_g
|
||
Set the gamma expression for green. The value must be a float in range
|
||
@code{0.1} to @code{10.0}. The default value is "1".
|
||
|
||
@item gamma_b
|
||
Set the gamma expression for blue. The value must be a float in range
|
||
@code{0.1} to @code{10.0}. The default value is "1".
|
||
|
||
@item gamma_weight
|
||
Set the gamma weight expression. It can be used to reduce the effect
|
||
of a high gamma value on bright image areas, e.g. keep them from
|
||
getting overamplified and just plain white. The value must be a float
|
||
in range @code{0.0} to @code{1.0}. A value of @code{0.0} turns the
|
||
gamma correction all the way down while @code{1.0} leaves it at its
|
||
full strength. Default is "1".
|
||
|
||
@item eval
|
||
Set when the expressions for brightness, contrast, saturation and
|
||
gamma expressions are evaluated.
|
||
|
||
It accepts the following values:
|
||
@table @samp
|
||
@item init
|
||
only evaluate expressions once during the filter initialization or
|
||
when a command is processed
|
||
|
||
@item frame
|
||
evaluate expressions for each incoming frame
|
||
@end table
|
||
|
||
Default value is @samp{init}.
|
||
@end table
|
||
|
||
The expressions accept the following parameters:
|
||
@table @option
|
||
@item n
|
||
frame count of the input frame starting from 0
|
||
|
||
@item pos
|
||
byte position of the corresponding packet in the input file, NAN if
|
||
unspecified
|
||
|
||
@item r
|
||
frame rate of the input video, NAN if the input frame rate is unknown
|
||
|
||
@item t
|
||
timestamp expressed in seconds, NAN if the input timestamp is unknown
|
||
@end table
|
||
|
||
@subsection Commands
|
||
The filter supports the following commands:
|
||
|
||
@table @option
|
||
@item contrast
|
||
Set the contrast expression.
|
||
|
||
@item brightness
|
||
Set the brightness expression.
|
||
|
||
@item saturation
|
||
Set the saturation expression.
|
||
|
||
@item gamma
|
||
Set the gamma expression.
|
||
|
||
@item gamma_r
|
||
Set the gamma_r expression.
|
||
|
||
@item gamma_g
|
||
Set gamma_g expression.
|
||
|
||
@item gamma_b
|
||
Set gamma_b expression.
|
||
|
||
@item gamma_weight
|
||
Set gamma_weight expression.
|
||
|
||
The command accepts the same syntax of the corresponding option.
|
||
|
||
If the specified expression is not valid, it is kept at its current
|
||
value.
|
||
|
||
@end table
|
||
|
||
@section erosion
|
||
|
||
Apply erosion effect to the video.
|
||
|
||
This filter replaces the pixel by the local(3x3) minimum.
|
||
|
||
It accepts the following options:
|
||
|
||
@table @option
|
||
@item threshold0
|
||
@item threshold1
|
||
@item threshold2
|
||
@item threshold3
|
||
Limit the maximum change for each plane, default is 65535.
|
||
If 0, plane will remain unchanged.
|
||
|
||
@item coordinates
|
||
Flag which specifies the pixel to refer to. Default is 255 i.e. all eight
|
||
pixels are used.
|
||
|
||
Flags to local 3x3 coordinates maps like this:
|
||
|
||
1 2 3
|
||
4 5
|
||
6 7 8
|
||
@end table
|
||
|
||
@section extractplanes
|
||
|
||
Extract color channel components from input video stream into
|
||
separate grayscale video streams.
|
||
|
||
The filter accepts the following option:
|
||
|
||
@table @option
|
||
@item planes
|
||
Set plane(s) to extract.
|
||
|
||
Available values for planes are:
|
||
@table @samp
|
||
@item y
|
||
@item u
|
||
@item v
|
||
@item a
|
||
@item r
|
||
@item g
|
||
@item b
|
||
@end table
|
||
|
||
Choosing planes not available in the input will result in an error.
|
||
That means you cannot select @code{r}, @code{g}, @code{b} planes
|
||
with @code{y}, @code{u}, @code{v} planes at same time.
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Extract luma, u and v color channel component from input video frame
|
||
into 3 grayscale outputs:
|
||
@example
|
||
ffmpeg -i video.avi -filter_complex 'extractplanes=y+u+v[y][u][v]' -map '[y]' y.avi -map '[u]' u.avi -map '[v]' v.avi
|
||
@end example
|
||
@end itemize
|
||
|
||
@section elbg
|
||
|
||
Apply a posterize effect using the ELBG (Enhanced LBG) algorithm.
|
||
|
||
For each input image, the filter will compute the optimal mapping from
|
||
the input to the output given the codebook length, that is the number
|
||
of distinct output colors.
|
||
|
||
This filter accepts the following options.
|
||
|
||
@table @option
|
||
@item codebook_length, l
|
||
Set codebook length. The value must be a positive integer, and
|
||
represents the number of distinct output colors. Default value is 256.
|
||
|
||
@item nb_steps, n
|
||
Set the maximum number of iterations to apply for computing the optimal
|
||
mapping. The higher the value the better the result and the higher the
|
||
computation time. Default value is 1.
|
||
|
||
@item seed, s
|
||
Set a random seed, must be an integer included between 0 and
|
||
UINT32_MAX. If not specified, or if explicitly set to -1, the filter
|
||
will try to use a good random seed on a best effort basis.
|
||
|
||
@item pal8
|
||
Set pal8 output pixel format. This option does not work with codebook
|
||
length greater than 256.
|
||
@end table
|
||
|
||
@section fade
|
||
|
||
Apply a fade-in/out effect to the input video.
|
||
|
||
It accepts the following parameters:
|
||
|
||
@table @option
|
||
@item type, t
|
||
The effect type can be either "in" for a fade-in, or "out" for a fade-out
|
||
effect.
|
||
Default is @code{in}.
|
||
|
||
@item start_frame, s
|
||
Specify the number of the frame to start applying the fade
|
||
effect at. Default is 0.
|
||
|
||
@item nb_frames, n
|
||
The number of frames that the fade effect lasts. At the end of the
|
||
fade-in effect, the output video will have the same intensity as the input video.
|
||
At the end of the fade-out transition, the output video will be filled with the
|
||
selected @option{color}.
|
||
Default is 25.
|
||
|
||
@item alpha
|
||
If set to 1, fade only alpha channel, if one exists on the input.
|
||
Default value is 0.
|
||
|
||
@item start_time, st
|
||
Specify the timestamp (in seconds) of the frame to start to apply the fade
|
||
effect. If both start_frame and start_time are specified, the fade will start at
|
||
whichever comes last. Default is 0.
|
||
|
||
@item duration, d
|
||
The number of seconds for which the fade effect has to last. At the end of the
|
||
fade-in effect the output video will have the same intensity as the input video,
|
||
at the end of the fade-out transition the output video will be filled with the
|
||
selected @option{color}.
|
||
If both duration and nb_frames are specified, duration is used. Default is 0
|
||
(nb_frames is used by default).
|
||
|
||
@item color, c
|
||
Specify the color of the fade. Default is "black".
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Fade in the first 30 frames of video:
|
||
@example
|
||
fade=in:0:30
|
||
@end example
|
||
|
||
The command above is equivalent to:
|
||
@example
|
||
fade=t=in:s=0:n=30
|
||
@end example
|
||
|
||
@item
|
||
Fade out the last 45 frames of a 200-frame video:
|
||
@example
|
||
fade=out:155:45
|
||
fade=type=out:start_frame=155:nb_frames=45
|
||
@end example
|
||
|
||
@item
|
||
Fade in the first 25 frames and fade out the last 25 frames of a 1000-frame video:
|
||
@example
|
||
fade=in:0:25, fade=out:975:25
|
||
@end example
|
||
|
||
@item
|
||
Make the first 5 frames yellow, then fade in from frame 5-24:
|
||
@example
|
||
fade=in:5:20:color=yellow
|
||
@end example
|
||
|
||
@item
|
||
Fade in alpha over first 25 frames of video:
|
||
@example
|
||
fade=in:0:25:alpha=1
|
||
@end example
|
||
|
||
@item
|
||
Make the first 5.5 seconds black, then fade in for 0.5 seconds:
|
||
@example
|
||
fade=t=in:st=5.5:d=0.5
|
||
@end example
|
||
|
||
@end itemize
|
||
|
||
@section fftfilt
|
||
Apply arbitrary expressions to samples in frequency domain
|
||
|
||
@table @option
|
||
@item dc_Y
|
||
Adjust the dc value (gain) of the luma plane of the image. The filter
|
||
accepts an integer value in range @code{0} to @code{1000}. The default
|
||
value is set to @code{0}.
|
||
|
||
@item dc_U
|
||
Adjust the dc value (gain) of the 1st chroma plane of the image. The
|
||
filter accepts an integer value in range @code{0} to @code{1000}. The
|
||
default value is set to @code{0}.
|
||
|
||
@item dc_V
|
||
Adjust the dc value (gain) of the 2nd chroma plane of the image. The
|
||
filter accepts an integer value in range @code{0} to @code{1000}. The
|
||
default value is set to @code{0}.
|
||
|
||
@item weight_Y
|
||
Set the frequency domain weight expression for the luma plane.
|
||
|
||
@item weight_U
|
||
Set the frequency domain weight expression for the 1st chroma plane.
|
||
|
||
@item weight_V
|
||
Set the frequency domain weight expression for the 2nd chroma plane.
|
||
|
||
The filter accepts the following variables:
|
||
@item X
|
||
@item Y
|
||
The coordinates of the current sample.
|
||
|
||
@item W
|
||
@item H
|
||
The width and height of the image.
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
High-pass:
|
||
@example
|
||
fftfilt=dc_Y=128:weight_Y='squish(1-(Y+X)/100)'
|
||
@end example
|
||
|
||
@item
|
||
Low-pass:
|
||
@example
|
||
fftfilt=dc_Y=0:weight_Y='squish((Y+X)/100-1)'
|
||
@end example
|
||
|
||
@item
|
||
Sharpen:
|
||
@example
|
||
fftfilt=dc_Y=0:weight_Y='1+squish(1-(Y+X)/100)'
|
||
@end example
|
||
|
||
@item
|
||
Blur:
|
||
@example
|
||
fftfilt=dc_Y=0:weight_Y='exp(-4 * ((Y+X)/(W+H)))'
|
||
@end example
|
||
|
||
@end itemize
|
||
|
||
@section field
|
||
|
||
Extract a single field from an interlaced image using stride
|
||
arithmetic to avoid wasting CPU time. The output frames are marked as
|
||
non-interlaced.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item type
|
||
Specify whether to extract the top (if the value is @code{0} or
|
||
@code{top}) or the bottom field (if the value is @code{1} or
|
||
@code{bottom}).
|
||
@end table
|
||
|
||
@section fieldhint
|
||
|
||
Create new frames by copying the top and bottom fields from surrounding frames
|
||
supplied as numbers by the hint file.
|
||
|
||
@table @option
|
||
@item hint
|
||
Set file containing hints: absolute/relative frame numbers.
|
||
|
||
There must be one line for each frame in a clip. Each line must contain two
|
||
numbers separated by the comma, optionally followed by @code{-} or @code{+}.
|
||
Numbers supplied on each line of file can not be out of [N-1,N+1] where N
|
||
is current frame number for @code{absolute} mode or out of [-1, 1] range
|
||
for @code{relative} mode. First number tells from which frame to pick up top
|
||
field and second number tells from which frame to pick up bottom field.
|
||
|
||
If optionally followed by @code{+} output frame will be marked as interlaced,
|
||
else if followed by @code{-} output frame will be marked as progressive, else
|
||
it will be marked same as input frame.
|
||
If line starts with @code{#} or @code{;} that line is skipped.
|
||
|
||
@item mode
|
||
Can be item @code{absolute} or @code{relative}. Default is @code{absolute}.
|
||
@end table
|
||
|
||
Example of first several lines of @code{hint} file for @code{relative} mode:
|
||
@example
|
||
0,0 - # first frame
|
||
1,0 - # second frame, use third's frame top field and second's frame bottom field
|
||
1,0 - # third frame, use fourth's frame top field and third's frame bottom field
|
||
1,0 -
|
||
0,0 -
|
||
0,0 -
|
||
1,0 -
|
||
1,0 -
|
||
1,0 -
|
||
0,0 -
|
||
0,0 -
|
||
1,0 -
|
||
1,0 -
|
||
1,0 -
|
||
0,0 -
|
||
@end example
|
||
|
||
@section fieldmatch
|
||
|
||
Field matching filter for inverse telecine. It is meant to reconstruct the
|
||
progressive frames from a telecined stream. The filter does not drop duplicated
|
||
frames, so to achieve a complete inverse telecine @code{fieldmatch} needs to be
|
||
followed by a decimation filter such as @ref{decimate} in the filtergraph.
|
||
|
||
The separation of the field matching and the decimation is notably motivated by
|
||
the possibility of inserting a de-interlacing filter fallback between the two.
|
||
If the source has mixed telecined and real interlaced content,
|
||
@code{fieldmatch} will not be able to match fields for the interlaced parts.
|
||
But these remaining combed frames will be marked as interlaced, and thus can be
|
||
de-interlaced by a later filter such as @ref{yadif} before decimation.
|
||
|
||
In addition to the various configuration options, @code{fieldmatch} can take an
|
||
optional second stream, activated through the @option{ppsrc} option. If
|
||
enabled, the frames reconstruction will be based on the fields and frames from
|
||
this second stream. This allows the first input to be pre-processed in order to
|
||
help the various algorithms of the filter, while keeping the output lossless
|
||
(assuming the fields are matched properly). Typically, a field-aware denoiser,
|
||
or brightness/contrast adjustments can help.
|
||
|
||
Note that this filter uses the same algorithms as TIVTC/TFM (AviSynth project)
|
||
and VIVTC/VFM (VapourSynth project). The later is a light clone of TFM from
|
||
which @code{fieldmatch} is based on. While the semantic and usage are very
|
||
close, some behaviour and options names can differ.
|
||
|
||
The @ref{decimate} filter currently only works for constant frame rate input.
|
||
If your input has mixed telecined (30fps) and progressive content with a lower
|
||
framerate like 24fps use the following filterchain to produce the necessary cfr
|
||
stream: @code{dejudder,fps=30000/1001,fieldmatch,decimate}.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item order
|
||
Specify the assumed field order of the input stream. Available values are:
|
||
|
||
@table @samp
|
||
@item auto
|
||
Auto detect parity (use FFmpeg's internal parity value).
|
||
@item bff
|
||
Assume bottom field first.
|
||
@item tff
|
||
Assume top field first.
|
||
@end table
|
||
|
||
Note that it is sometimes recommended not to trust the parity announced by the
|
||
stream.
|
||
|
||
Default value is @var{auto}.
|
||
|
||
@item mode
|
||
Set the matching mode or strategy to use. @option{pc} mode is the safest in the
|
||
sense that it won't risk creating jerkiness due to duplicate frames when
|
||
possible, but if there are bad edits or blended fields it will end up
|
||
outputting combed frames when a good match might actually exist. On the other
|
||
hand, @option{pcn_ub} mode is the most risky in terms of creating jerkiness,
|
||
but will almost always find a good frame if there is one. The other values are
|
||
all somewhere in between @option{pc} and @option{pcn_ub} in terms of risking
|
||
jerkiness and creating duplicate frames versus finding good matches in sections
|
||
with bad edits, orphaned fields, blended fields, etc.
|
||
|
||
More details about p/c/n/u/b are available in @ref{p/c/n/u/b meaning} section.
|
||
|
||
Available values are:
|
||
|
||
@table @samp
|
||
@item pc
|
||
2-way matching (p/c)
|
||
@item pc_n
|
||
2-way matching, and trying 3rd match if still combed (p/c + n)
|
||
@item pc_u
|
||
2-way matching, and trying 3rd match (same order) if still combed (p/c + u)
|
||
@item pc_n_ub
|
||
2-way matching, trying 3rd match if still combed, and trying 4th/5th matches if
|
||
still combed (p/c + n + u/b)
|
||
@item pcn
|
||
3-way matching (p/c/n)
|
||
@item pcn_ub
|
||
3-way matching, and trying 4th/5th matches if all 3 of the original matches are
|
||
detected as combed (p/c/n + u/b)
|
||
@end table
|
||
|
||
The parenthesis at the end indicate the matches that would be used for that
|
||
mode assuming @option{order}=@var{tff} (and @option{field} on @var{auto} or
|
||
@var{top}).
|
||
|
||
In terms of speed @option{pc} mode is by far the fastest and @option{pcn_ub} is
|
||
the slowest.
|
||
|
||
Default value is @var{pc_n}.
|
||
|
||
@item ppsrc
|
||
Mark the main input stream as a pre-processed input, and enable the secondary
|
||
input stream as the clean source to pick the fields from. See the filter
|
||
introduction for more details. It is similar to the @option{clip2} feature from
|
||
VFM/TFM.
|
||
|
||
Default value is @code{0} (disabled).
|
||
|
||
@item field
|
||
Set the field to match from. It is recommended to set this to the same value as
|
||
@option{order} unless you experience matching failures with that setting. In
|
||
certain circumstances changing the field that is used to match from can have a
|
||
large impact on matching performance. Available values are:
|
||
|
||
@table @samp
|
||
@item auto
|
||
Automatic (same value as @option{order}).
|
||
@item bottom
|
||
Match from the bottom field.
|
||
@item top
|
||
Match from the top field.
|
||
@end table
|
||
|
||
Default value is @var{auto}.
|
||
|
||
@item mchroma
|
||
Set whether or not chroma is included during the match comparisons. In most
|
||
cases it is recommended to leave this enabled. You should set this to @code{0}
|
||
only if your clip has bad chroma problems such as heavy rainbowing or other
|
||
artifacts. Setting this to @code{0} could also be used to speed things up at
|
||
the cost of some accuracy.
|
||
|
||
Default value is @code{1}.
|
||
|
||
@item y0
|
||
@item y1
|
||
These define an exclusion band which excludes the lines between @option{y0} and
|
||
@option{y1} from being included in the field matching decision. An exclusion
|
||
band can be used to ignore subtitles, a logo, or other things that may
|
||
interfere with the matching. @option{y0} sets the starting scan line and
|
||
@option{y1} sets the ending line; all lines in between @option{y0} and
|
||
@option{y1} (including @option{y0} and @option{y1}) will be ignored. Setting
|
||
@option{y0} and @option{y1} to the same value will disable the feature.
|
||
@option{y0} and @option{y1} defaults to @code{0}.
|
||
|
||
@item scthresh
|
||
Set the scene change detection threshold as a percentage of maximum change on
|
||
the luma plane. Good values are in the @code{[8.0, 14.0]} range. Scene change
|
||
detection is only relevant in case @option{combmatch}=@var{sc}. The range for
|
||
@option{scthresh} is @code{[0.0, 100.0]}.
|
||
|
||
Default value is @code{12.0}.
|
||
|
||
@item combmatch
|
||
When @option{combatch} is not @var{none}, @code{fieldmatch} will take into
|
||
account the combed scores of matches when deciding what match to use as the
|
||
final match. Available values are:
|
||
|
||
@table @samp
|
||
@item none
|
||
No final matching based on combed scores.
|
||
@item sc
|
||
Combed scores are only used when a scene change is detected.
|
||
@item full
|
||
Use combed scores all the time.
|
||
@end table
|
||
|
||
Default is @var{sc}.
|
||
|
||
@item combdbg
|
||
Force @code{fieldmatch} to calculate the combed metrics for certain matches and
|
||
print them. This setting is known as @option{micout} in TFM/VFM vocabulary.
|
||
Available values are:
|
||
|
||
@table @samp
|
||
@item none
|
||
No forced calculation.
|
||
@item pcn
|
||
Force p/c/n calculations.
|
||
@item pcnub
|
||
Force p/c/n/u/b calculations.
|
||
@end table
|
||
|
||
Default value is @var{none}.
|
||
|
||
@item cthresh
|
||
This is the area combing threshold used for combed frame detection. This
|
||
essentially controls how "strong" or "visible" combing must be to be detected.
|
||
Larger values mean combing must be more visible and smaller values mean combing
|
||
can be less visible or strong and still be detected. Valid settings are from
|
||
@code{-1} (every pixel will be detected as combed) to @code{255} (no pixel will
|
||
be detected as combed). This is basically a pixel difference value. A good
|
||
range is @code{[8, 12]}.
|
||
|
||
Default value is @code{9}.
|
||
|
||
@item chroma
|
||
Sets whether or not chroma is considered in the combed frame decision. Only
|
||
disable this if your source has chroma problems (rainbowing, etc.) that are
|
||
causing problems for the combed frame detection with chroma enabled. Actually,
|
||
using @option{chroma}=@var{0} is usually more reliable, except for the case
|
||
where there is chroma only combing in the source.
|
||
|
||
Default value is @code{0}.
|
||
|
||
@item blockx
|
||
@item blocky
|
||
Respectively set the x-axis and y-axis size of the window used during combed
|
||
frame detection. This has to do with the size of the area in which
|
||
@option{combpel} pixels are required to be detected as combed for a frame to be
|
||
declared combed. See the @option{combpel} parameter description for more info.
|
||
Possible values are any number that is a power of 2 starting at 4 and going up
|
||
to 512.
|
||
|
||
Default value is @code{16}.
|
||
|
||
@item combpel
|
||
The number of combed pixels inside any of the @option{blocky} by
|
||
@option{blockx} size blocks on the frame for the frame to be detected as
|
||
combed. While @option{cthresh} controls how "visible" the combing must be, this
|
||
setting controls "how much" combing there must be in any localized area (a
|
||
window defined by the @option{blockx} and @option{blocky} settings) on the
|
||
frame. Minimum value is @code{0} and maximum is @code{blocky x blockx} (at
|
||
which point no frames will ever be detected as combed). This setting is known
|
||
as @option{MI} in TFM/VFM vocabulary.
|
||
|
||
Default value is @code{80}.
|
||
@end table
|
||
|
||
@anchor{p/c/n/u/b meaning}
|
||
@subsection p/c/n/u/b meaning
|
||
|
||
@subsubsection p/c/n
|
||
|
||
We assume the following telecined stream:
|
||
|
||
@example
|
||
Top fields: 1 2 2 3 4
|
||
Bottom fields: 1 2 3 4 4
|
||
@end example
|
||
|
||
The numbers correspond to the progressive frame the fields relate to. Here, the
|
||
first two frames are progressive, the 3rd and 4th are combed, and so on.
|
||
|
||
When @code{fieldmatch} is configured to run a matching from bottom
|
||
(@option{field}=@var{bottom}) this is how this input stream get transformed:
|
||
|
||
@example
|
||
Input stream:
|
||
T 1 2 2 3 4
|
||
B 1 2 3 4 4 <-- matching reference
|
||
|
||
Matches: c c n n c
|
||
|
||
Output stream:
|
||
T 1 2 3 4 4
|
||
B 1 2 3 4 4
|
||
@end example
|
||
|
||
As a result of the field matching, we can see that some frames get duplicated.
|
||
To perform a complete inverse telecine, you need to rely on a decimation filter
|
||
after this operation. See for instance the @ref{decimate} filter.
|
||
|
||
The same operation now matching from top fields (@option{field}=@var{top})
|
||
looks like this:
|
||
|
||
@example
|
||
Input stream:
|
||
T 1 2 2 3 4 <-- matching reference
|
||
B 1 2 3 4 4
|
||
|
||
Matches: c c p p c
|
||
|
||
Output stream:
|
||
T 1 2 2 3 4
|
||
B 1 2 2 3 4
|
||
@end example
|
||
|
||
In these examples, we can see what @var{p}, @var{c} and @var{n} mean;
|
||
basically, they refer to the frame and field of the opposite parity:
|
||
|
||
@itemize
|
||
@item @var{p} matches the field of the opposite parity in the previous frame
|
||
@item @var{c} matches the field of the opposite parity in the current frame
|
||
@item @var{n} matches the field of the opposite parity in the next frame
|
||
@end itemize
|
||
|
||
@subsubsection u/b
|
||
|
||
The @var{u} and @var{b} matching are a bit special in the sense that they match
|
||
from the opposite parity flag. In the following examples, we assume that we are
|
||
currently matching the 2nd frame (Top:2, bottom:2). According to the match, a
|
||
'x' is placed above and below each matched fields.
|
||
|
||
With bottom matching (@option{field}=@var{bottom}):
|
||
@example
|
||
Match: c p n b u
|
||
|
||
x x x x x
|
||
Top 1 2 2 1 2 2 1 2 2 1 2 2 1 2 2
|
||
Bottom 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3
|
||
x x x x x
|
||
|
||
Output frames:
|
||
2 1 2 2 2
|
||
2 2 2 1 3
|
||
@end example
|
||
|
||
With top matching (@option{field}=@var{top}):
|
||
@example
|
||
Match: c p n b u
|
||
|
||
x x x x x
|
||
Top 1 2 2 1 2 2 1 2 2 1 2 2 1 2 2
|
||
Bottom 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3
|
||
x x x x x
|
||
|
||
Output frames:
|
||
2 2 2 1 2
|
||
2 1 3 2 2
|
||
@end example
|
||
|
||
@subsection Examples
|
||
|
||
Simple IVTC of a top field first telecined stream:
|
||
@example
|
||
fieldmatch=order=tff:combmatch=none, decimate
|
||
@end example
|
||
|
||
Advanced IVTC, with fallback on @ref{yadif} for still combed frames:
|
||
@example
|
||
fieldmatch=order=tff:combmatch=full, yadif=deint=interlaced, decimate
|
||
@end example
|
||
|
||
@section fieldorder
|
||
|
||
Transform the field order of the input video.
|
||
|
||
It accepts the following parameters:
|
||
|
||
@table @option
|
||
|
||
@item order
|
||
The output field order. Valid values are @var{tff} for top field first or @var{bff}
|
||
for bottom field first.
|
||
@end table
|
||
|
||
The default value is @samp{tff}.
|
||
|
||
The transformation is done by shifting the picture content up or down
|
||
by one line, and filling the remaining line with appropriate picture content.
|
||
This method is consistent with most broadcast field order converters.
|
||
|
||
If the input video is not flagged as being interlaced, or it is already
|
||
flagged as being of the required output field order, then this filter does
|
||
not alter the incoming video.
|
||
|
||
It is very useful when converting to or from PAL DV material,
|
||
which is bottom field first.
|
||
|
||
For example:
|
||
@example
|
||
ffmpeg -i in.vob -vf "fieldorder=bff" out.dv
|
||
@end example
|
||
|
||
@section fifo, afifo
|
||
|
||
Buffer input images and send them when they are requested.
|
||
|
||
It is mainly useful when auto-inserted by the libavfilter
|
||
framework.
|
||
|
||
It does not take parameters.
|
||
|
||
@section find_rect
|
||
|
||
Find a rectangular object
|
||
|
||
It accepts the following options:
|
||
|
||
@table @option
|
||
@item object
|
||
Filepath of the object image, needs to be in gray8.
|
||
|
||
@item threshold
|
||
Detection threshold, default is 0.5.
|
||
|
||
@item mipmaps
|
||
Number of mipmaps, default is 3.
|
||
|
||
@item xmin, ymin, xmax, ymax
|
||
Specifies the rectangle in which to search.
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Generate a representative palette of a given video using @command{ffmpeg}:
|
||
@example
|
||
ffmpeg -i file.ts -vf find_rect=newref.pgm,cover_rect=cover.jpg:mode=cover new.mkv
|
||
@end example
|
||
@end itemize
|
||
|
||
@section cover_rect
|
||
|
||
Cover a rectangular object
|
||
|
||
It accepts the following options:
|
||
|
||
@table @option
|
||
@item cover
|
||
Filepath of the optional cover image, needs to be in yuv420.
|
||
|
||
@item mode
|
||
Set covering mode.
|
||
|
||
It accepts the following values:
|
||
@table @samp
|
||
@item cover
|
||
cover it by the supplied image
|
||
@item blur
|
||
cover it by interpolating the surrounding pixels
|
||
@end table
|
||
|
||
Default value is @var{blur}.
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Generate a representative palette of a given video using @command{ffmpeg}:
|
||
@example
|
||
ffmpeg -i file.ts -vf find_rect=newref.pgm,cover_rect=cover.jpg:mode=cover new.mkv
|
||
@end example
|
||
@end itemize
|
||
|
||
@anchor{format}
|
||
@section format
|
||
|
||
Convert the input video to one of the specified pixel formats.
|
||
Libavfilter will try to pick one that is suitable as input to
|
||
the next filter.
|
||
|
||
It accepts the following parameters:
|
||
@table @option
|
||
|
||
@item pix_fmts
|
||
A '|'-separated list of pixel format names, such as
|
||
"pix_fmts=yuv420p|monow|rgb24".
|
||
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Convert the input video to the @var{yuv420p} format
|
||
@example
|
||
format=pix_fmts=yuv420p
|
||
@end example
|
||
|
||
Convert the input video to any of the formats in the list
|
||
@example
|
||
format=pix_fmts=yuv420p|yuv444p|yuv410p
|
||
@end example
|
||
@end itemize
|
||
|
||
@anchor{fps}
|
||
@section fps
|
||
|
||
Convert the video to specified constant frame rate by duplicating or dropping
|
||
frames as necessary.
|
||
|
||
It accepts the following parameters:
|
||
@table @option
|
||
|
||
@item fps
|
||
The desired output frame rate. The default is @code{25}.
|
||
|
||
@item round
|
||
Rounding method.
|
||
|
||
Possible values are:
|
||
@table @option
|
||
@item zero
|
||
zero round towards 0
|
||
@item inf
|
||
round away from 0
|
||
@item down
|
||
round towards -infinity
|
||
@item up
|
||
round towards +infinity
|
||
@item near
|
||
round to nearest
|
||
@end table
|
||
The default is @code{near}.
|
||
|
||
@item start_time
|
||
Assume the first PTS should be the given value, in seconds. This allows for
|
||
padding/trimming at the start of stream. By default, no assumption is made
|
||
about the first frame's expected PTS, so no padding or trimming is done.
|
||
For example, this could be set to 0 to pad the beginning with duplicates of
|
||
the first frame if a video stream starts after the audio stream or to trim any
|
||
frames with a negative PTS.
|
||
|
||
@end table
|
||
|
||
Alternatively, the options can be specified as a flat string:
|
||
@var{fps}[:@var{round}].
|
||
|
||
See also the @ref{setpts} filter.
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
A typical usage in order to set the fps to 25:
|
||
@example
|
||
fps=fps=25
|
||
@end example
|
||
|
||
@item
|
||
Sets the fps to 24, using abbreviation and rounding method to round to nearest:
|
||
@example
|
||
fps=fps=film:round=near
|
||
@end example
|
||
@end itemize
|
||
|
||
@section framepack
|
||
|
||
Pack two different video streams into a stereoscopic video, setting proper
|
||
metadata on supported codecs. The two views should have the same size and
|
||
framerate and processing will stop when the shorter video ends. Please note
|
||
that you may conveniently adjust view properties with the @ref{scale} and
|
||
@ref{fps} filters.
|
||
|
||
It accepts the following parameters:
|
||
@table @option
|
||
|
||
@item format
|
||
The desired packing format. Supported values are:
|
||
|
||
@table @option
|
||
|
||
@item sbs
|
||
The views are next to each other (default).
|
||
|
||
@item tab
|
||
The views are on top of each other.
|
||
|
||
@item lines
|
||
The views are packed by line.
|
||
|
||
@item columns
|
||
The views are packed by column.
|
||
|
||
@item frameseq
|
||
The views are temporally interleaved.
|
||
|
||
@end table
|
||
|
||
@end table
|
||
|
||
Some examples:
|
||
|
||
@example
|
||
# Convert left and right views into a frame-sequential video
|
||
ffmpeg -i LEFT -i RIGHT -filter_complex framepack=frameseq OUTPUT
|
||
|
||
# Convert views into a side-by-side video with the same output resolution as the input
|
||
ffmpeg -i LEFT -i RIGHT -filter_complex [0:v]scale=w=iw/2[left],[1:v]scale=w=iw/2[right],[left][right]framepack=sbs OUTPUT
|
||
@end example
|
||
|
||
@section framerate
|
||
|
||
Change the frame rate by interpolating new video output frames from the source
|
||
frames.
|
||
|
||
This filter is not designed to function correctly with interlaced media. If
|
||
you wish to change the frame rate of interlaced media then you are required
|
||
to deinterlace before this filter and re-interlace after this filter.
|
||
|
||
A description of the accepted options follows.
|
||
|
||
@table @option
|
||
@item fps
|
||
Specify the output frames per second. This option can also be specified
|
||
as a value alone. The default is @code{50}.
|
||
|
||
@item interp_start
|
||
Specify the start of a range where the output frame will be created as a
|
||
linear interpolation of two frames. The range is [@code{0}-@code{255}],
|
||
the default is @code{15}.
|
||
|
||
@item interp_end
|
||
Specify the end of a range where the output frame will be created as a
|
||
linear interpolation of two frames. The range is [@code{0}-@code{255}],
|
||
the default is @code{240}.
|
||
|
||
@item scene
|
||
Specify the level at which a scene change is detected as a value between
|
||
0 and 100 to indicate a new scene; a low value reflects a low
|
||
probability for the current frame to introduce a new scene, while a higher
|
||
value means the current frame is more likely to be one.
|
||
The default is @code{7}.
|
||
|
||
@item flags
|
||
Specify flags influencing the filter process.
|
||
|
||
Available value for @var{flags} is:
|
||
|
||
@table @option
|
||
@item scene_change_detect, scd
|
||
Enable scene change detection using the value of the option @var{scene}.
|
||
This flag is enabled by default.
|
||
@end table
|
||
@end table
|
||
|
||
@section framestep
|
||
|
||
Select one frame every N-th frame.
|
||
|
||
This filter accepts the following option:
|
||
@table @option
|
||
@item step
|
||
Select frame after every @code{step} frames.
|
||
Allowed values are positive integers higher than 0. Default value is @code{1}.
|
||
@end table
|
||
|
||
@anchor{frei0r}
|
||
@section frei0r
|
||
|
||
Apply a frei0r effect to the input video.
|
||
|
||
To enable the compilation of this filter, you need to install the frei0r
|
||
header and configure FFmpeg with @code{--enable-frei0r}.
|
||
|
||
It accepts the following parameters:
|
||
|
||
@table @option
|
||
|
||
@item filter_name
|
||
The name of the frei0r effect to load. If the environment variable
|
||
@env{FREI0R_PATH} is defined, the frei0r effect is searched for in each of the
|
||
directories specified by the colon-separated list in @env{FREI0R_PATH}.
|
||
Otherwise, the standard frei0r paths are searched, in this order:
|
||
@file{HOME/.frei0r-1/lib/}, @file{/usr/local/lib/frei0r-1/},
|
||
@file{/usr/lib/frei0r-1/}.
|
||
|
||
@item filter_params
|
||
A '|'-separated list of parameters to pass to the frei0r effect.
|
||
|
||
@end table
|
||
|
||
A frei0r effect parameter can be a boolean (its value is either
|
||
"y" or "n"), a double, a color (specified as
|
||
@var{R}/@var{G}/@var{B}, where @var{R}, @var{G}, and @var{B} are floating point
|
||
numbers between 0.0 and 1.0, inclusive) or by a color description specified in the "Color"
|
||
section in the ffmpeg-utils manual), a position (specified as @var{X}/@var{Y}, where
|
||
@var{X} and @var{Y} are floating point numbers) and/or a string.
|
||
|
||
The number and types of parameters depend on the loaded effect. If an
|
||
effect parameter is not specified, the default value is set.
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Apply the distort0r effect, setting the first two double parameters:
|
||
@example
|
||
frei0r=filter_name=distort0r:filter_params=0.5|0.01
|
||
@end example
|
||
|
||
@item
|
||
Apply the colordistance effect, taking a color as the first parameter:
|
||
@example
|
||
frei0r=colordistance:0.2/0.3/0.4
|
||
frei0r=colordistance:violet
|
||
frei0r=colordistance:0x112233
|
||
@end example
|
||
|
||
@item
|
||
Apply the perspective effect, specifying the top left and top right image
|
||
positions:
|
||
@example
|
||
frei0r=perspective:0.2/0.2|0.8/0.2
|
||
@end example
|
||
@end itemize
|
||
|
||
For more information, see
|
||
@url{http://frei0r.dyne.org}
|
||
|
||
@section fspp
|
||
|
||
Apply fast and simple postprocessing. It is a faster version of @ref{spp}.
|
||
|
||
It splits (I)DCT into horizontal/vertical passes. Unlike the simple post-
|
||
processing filter, one of them is performed once per block, not per pixel.
|
||
This allows for much higher speed.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item quality
|
||
Set quality. This option defines the number of levels for averaging. It accepts
|
||
an integer in the range 4-5. Default value is @code{4}.
|
||
|
||
@item qp
|
||
Force a constant quantization parameter. It accepts an integer in range 0-63.
|
||
If not set, the filter will use the QP from the video stream (if available).
|
||
|
||
@item strength
|
||
Set filter strength. It accepts an integer in range -15 to 32. Lower values mean
|
||
more details but also more artifacts, while higher values make the image smoother
|
||
but also blurrier. Default value is @code{0} − PSNR optimal.
|
||
|
||
@item use_bframe_qp
|
||
Enable the use of the QP from the B-Frames if set to @code{1}. Using this
|
||
option may cause flicker since the B-Frames have often larger QP. Default is
|
||
@code{0} (not enabled).
|
||
|
||
@end table
|
||
|
||
@section gblur
|
||
|
||
Apply Gaussian blur filter.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item sigma
|
||
Set horizontal sigma, standard deviation of Gaussian blur. Default is @code{0.5}.
|
||
|
||
@item steps
|
||
Set number of steps for Gaussian approximation. Defauls is @code{1}.
|
||
|
||
@item planes
|
||
Set which planes to filter. By default all planes are filtered.
|
||
|
||
@item sigmaV
|
||
Set vertical sigma, if negative it will be same as @code{sigma}.
|
||
Default is @code{-1}.
|
||
@end table
|
||
|
||
@section geq
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item lum_expr, lum
|
||
Set the luminance expression.
|
||
@item cb_expr, cb
|
||
Set the chrominance blue expression.
|
||
@item cr_expr, cr
|
||
Set the chrominance red expression.
|
||
@item alpha_expr, a
|
||
Set the alpha expression.
|
||
@item red_expr, r
|
||
Set the red expression.
|
||
@item green_expr, g
|
||
Set the green expression.
|
||
@item blue_expr, b
|
||
Set the blue expression.
|
||
@end table
|
||
|
||
The colorspace is selected according to the specified options. If one
|
||
of the @option{lum_expr}, @option{cb_expr}, or @option{cr_expr}
|
||
options is specified, the filter will automatically select a YCbCr
|
||
colorspace. If one of the @option{red_expr}, @option{green_expr}, or
|
||
@option{blue_expr} options is specified, it will select an RGB
|
||
colorspace.
|
||
|
||
If one of the chrominance expression is not defined, it falls back on the other
|
||
one. If no alpha expression is specified it will evaluate to opaque value.
|
||
If none of chrominance expressions are specified, they will evaluate
|
||
to the luminance expression.
|
||
|
||
The expressions can use the following variables and functions:
|
||
|
||
@table @option
|
||
@item N
|
||
The sequential number of the filtered frame, starting from @code{0}.
|
||
|
||
@item X
|
||
@item Y
|
||
The coordinates of the current sample.
|
||
|
||
@item W
|
||
@item H
|
||
The width and height of the image.
|
||
|
||
@item SW
|
||
@item SH
|
||
Width and height scale depending on the currently filtered plane. It is the
|
||
ratio between the corresponding luma plane number of pixels and the current
|
||
plane ones. E.g. for YUV4:2:0 the values are @code{1,1} for the luma plane, and
|
||
@code{0.5,0.5} for chroma planes.
|
||
|
||
@item T
|
||
Time of the current frame, expressed in seconds.
|
||
|
||
@item p(x, y)
|
||
Return the value of the pixel at location (@var{x},@var{y}) of the current
|
||
plane.
|
||
|
||
@item lum(x, y)
|
||
Return the value of the pixel at location (@var{x},@var{y}) of the luminance
|
||
plane.
|
||
|
||
@item cb(x, y)
|
||
Return the value of the pixel at location (@var{x},@var{y}) of the
|
||
blue-difference chroma plane. Return 0 if there is no such plane.
|
||
|
||
@item cr(x, y)
|
||
Return the value of the pixel at location (@var{x},@var{y}) of the
|
||
red-difference chroma plane. Return 0 if there is no such plane.
|
||
|
||
@item r(x, y)
|
||
@item g(x, y)
|
||
@item b(x, y)
|
||
Return the value of the pixel at location (@var{x},@var{y}) of the
|
||
red/green/blue component. Return 0 if there is no such component.
|
||
|
||
@item alpha(x, y)
|
||
Return the value of the pixel at location (@var{x},@var{y}) of the alpha
|
||
plane. Return 0 if there is no such plane.
|
||
@end table
|
||
|
||
For functions, if @var{x} and @var{y} are outside the area, the value will be
|
||
automatically clipped to the closer edge.
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Flip the image horizontally:
|
||
@example
|
||
geq=p(W-X\,Y)
|
||
@end example
|
||
|
||
@item
|
||
Generate a bidimensional sine wave, with angle @code{PI/3} and a
|
||
wavelength of 100 pixels:
|
||
@example
|
||
geq=128 + 100*sin(2*(PI/100)*(cos(PI/3)*(X-50*T) + sin(PI/3)*Y)):128:128
|
||
@end example
|
||
|
||
@item
|
||
Generate a fancy enigmatic moving light:
|
||
@example
|
||
nullsrc=s=256x256,geq=random(1)/hypot(X-cos(N*0.07)*W/2-W/2\,Y-sin(N*0.09)*H/2-H/2)^2*1000000*sin(N*0.02):128:128
|
||
@end example
|
||
|
||
@item
|
||
Generate a quick emboss effect:
|
||
@example
|
||
format=gray,geq=lum_expr='(p(X,Y)+(256-p(X-4,Y-4)))/2'
|
||
@end example
|
||
|
||
@item
|
||
Modify RGB components depending on pixel position:
|
||
@example
|
||
geq=r='X/W*r(X,Y)':g='(1-X/W)*g(X,Y)':b='(H-Y)/H*b(X,Y)'
|
||
@end example
|
||
|
||
@item
|
||
Create a radial gradient that is the same size as the input (also see
|
||
the @ref{vignette} filter):
|
||
@example
|
||
geq=lum=255*gauss((X/W-0.5)*3)*gauss((Y/H-0.5)*3)/gauss(0)/gauss(0),format=gray
|
||
@end example
|
||
@end itemize
|
||
|
||
@section gradfun
|
||
|
||
Fix the banding artifacts that are sometimes introduced into nearly flat
|
||
regions by truncation to 8-bit color depth.
|
||
Interpolate the gradients that should go where the bands are, and
|
||
dither them.
|
||
|
||
It is designed for playback only. Do not use it prior to
|
||
lossy compression, because compression tends to lose the dither and
|
||
bring back the bands.
|
||
|
||
It accepts the following parameters:
|
||
|
||
@table @option
|
||
|
||
@item strength
|
||
The maximum amount by which the filter will change any one pixel. This is also
|
||
the threshold for detecting nearly flat regions. Acceptable values range from
|
||
.51 to 64; the default value is 1.2. Out-of-range values will be clipped to the
|
||
valid range.
|
||
|
||
@item radius
|
||
The neighborhood to fit the gradient to. A larger radius makes for smoother
|
||
gradients, but also prevents the filter from modifying the pixels near detailed
|
||
regions. Acceptable values are 8-32; the default value is 16. Out-of-range
|
||
values will be clipped to the valid range.
|
||
|
||
@end table
|
||
|
||
Alternatively, the options can be specified as a flat string:
|
||
@var{strength}[:@var{radius}]
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Apply the filter with a @code{3.5} strength and radius of @code{8}:
|
||
@example
|
||
gradfun=3.5:8
|
||
@end example
|
||
|
||
@item
|
||
Specify radius, omitting the strength (which will fall-back to the default
|
||
value):
|
||
@example
|
||
gradfun=radius=8
|
||
@end example
|
||
|
||
@end itemize
|
||
|
||
@anchor{haldclut}
|
||
@section haldclut
|
||
|
||
Apply a Hald CLUT to a video stream.
|
||
|
||
First input is the video stream to process, and second one is the Hald CLUT.
|
||
The Hald CLUT input can be a simple picture or a complete video stream.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item shortest
|
||
Force termination when the shortest input terminates. Default is @code{0}.
|
||
@item repeatlast
|
||
Continue applying the last CLUT after the end of the stream. A value of
|
||
@code{0} disable the filter after the last frame of the CLUT is reached.
|
||
Default is @code{1}.
|
||
@end table
|
||
|
||
@code{haldclut} also has the same interpolation options as @ref{lut3d} (both
|
||
filters share the same internals).
|
||
|
||
More information about the Hald CLUT can be found on Eskil Steenberg's website
|
||
(Hald CLUT author) at @url{http://www.quelsolaar.com/technology/clut.html}.
|
||
|
||
@subsection Workflow examples
|
||
|
||
@subsubsection Hald CLUT video stream
|
||
|
||
Generate an identity Hald CLUT stream altered with various effects:
|
||
@example
|
||
ffmpeg -f lavfi -i @ref{haldclutsrc}=8 -vf "hue=H=2*PI*t:s=sin(2*PI*t)+1, curves=cross_process" -t 10 -c:v ffv1 clut.nut
|
||
@end example
|
||
|
||
Note: make sure you use a lossless codec.
|
||
|
||
Then use it with @code{haldclut} to apply it on some random stream:
|
||
@example
|
||
ffmpeg -f lavfi -i mandelbrot -i clut.nut -filter_complex '[0][1] haldclut' -t 20 mandelclut.mkv
|
||
@end example
|
||
|
||
The Hald CLUT will be applied to the 10 first seconds (duration of
|
||
@file{clut.nut}), then the latest picture of that CLUT stream will be applied
|
||
to the remaining frames of the @code{mandelbrot} stream.
|
||
|
||
@subsubsection Hald CLUT with preview
|
||
|
||
A Hald CLUT is supposed to be a squared image of @code{Level*Level*Level} by
|
||
@code{Level*Level*Level} pixels. For a given Hald CLUT, FFmpeg will select the
|
||
biggest possible square starting at the top left of the picture. The remaining
|
||
padding pixels (bottom or right) will be ignored. This area can be used to add
|
||
a preview of the Hald CLUT.
|
||
|
||
Typically, the following generated Hald CLUT will be supported by the
|
||
@code{haldclut} filter:
|
||
|
||
@example
|
||
ffmpeg -f lavfi -i @ref{haldclutsrc}=8 -vf "
|
||
pad=iw+320 [padded_clut];
|
||
smptebars=s=320x256, split [a][b];
|
||
[padded_clut][a] overlay=W-320:h, curves=color_negative [main];
|
||
[main][b] overlay=W-320" -frames:v 1 clut.png
|
||
@end example
|
||
|
||
It contains the original and a preview of the effect of the CLUT: SMPTE color
|
||
bars are displayed on the right-top, and below the same color bars processed by
|
||
the color changes.
|
||
|
||
Then, the effect of this Hald CLUT can be visualized with:
|
||
@example
|
||
ffplay input.mkv -vf "movie=clut.png, [in] haldclut"
|
||
@end example
|
||
|
||
@section hflip
|
||
|
||
Flip the input video horizontally.
|
||
|
||
For example, to horizontally flip the input video with @command{ffmpeg}:
|
||
@example
|
||
ffmpeg -i in.avi -vf "hflip" out.avi
|
||
@end example
|
||
|
||
@section histeq
|
||
This filter applies a global color histogram equalization on a
|
||
per-frame basis.
|
||
|
||
It can be used to correct video that has a compressed range of pixel
|
||
intensities. The filter redistributes the pixel intensities to
|
||
equalize their distribution across the intensity range. It may be
|
||
viewed as an "automatically adjusting contrast filter". This filter is
|
||
useful only for correcting degraded or poorly captured source
|
||
video.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item strength
|
||
Determine the amount of equalization to be applied. As the strength
|
||
is reduced, the distribution of pixel intensities more-and-more
|
||
approaches that of the input frame. The value must be a float number
|
||
in the range [0,1] and defaults to 0.200.
|
||
|
||
@item intensity
|
||
Set the maximum intensity that can generated and scale the output
|
||
values appropriately. The strength should be set as desired and then
|
||
the intensity can be limited if needed to avoid washing-out. The value
|
||
must be a float number in the range [0,1] and defaults to 0.210.
|
||
|
||
@item antibanding
|
||
Set the antibanding level. If enabled the filter will randomly vary
|
||
the luminance of output pixels by a small amount to avoid banding of
|
||
the histogram. Possible values are @code{none}, @code{weak} or
|
||
@code{strong}. It defaults to @code{none}.
|
||
@end table
|
||
|
||
@section histogram
|
||
|
||
Compute and draw a color distribution histogram for the input video.
|
||
|
||
The computed histogram is a representation of the color component
|
||
distribution in an image.
|
||
|
||
Standard histogram displays the color components distribution in an image.
|
||
Displays color graph for each color component. Shows distribution of
|
||
the Y, U, V, A or R, G, B components, depending on input format, in the
|
||
current frame. Below each graph a color component scale meter is shown.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item level_height
|
||
Set height of level. Default value is @code{200}.
|
||
Allowed range is [50, 2048].
|
||
|
||
@item scale_height
|
||
Set height of color scale. Default value is @code{12}.
|
||
Allowed range is [0, 40].
|
||
|
||
@item display_mode
|
||
Set display mode.
|
||
It accepts the following values:
|
||
@table @samp
|
||
@item stack
|
||
Per color component graphs are placed below each other.
|
||
|
||
@item parade
|
||
Per color component graphs are placed side by side.
|
||
|
||
@item overlay
|
||
Presents information identical to that in the @code{parade}, except
|
||
that the graphs representing color components are superimposed directly
|
||
over one another.
|
||
@end table
|
||
Default is @code{stack}.
|
||
|
||
@item levels_mode
|
||
Set mode. Can be either @code{linear}, or @code{logarithmic}.
|
||
Default is @code{linear}.
|
||
|
||
@item components
|
||
Set what color components to display.
|
||
Default is @code{7}.
|
||
|
||
@item fgopacity
|
||
Set foreground opacity. Default is @code{0.7}.
|
||
|
||
@item bgopacity
|
||
Set background opacity. Default is @code{0.5}.
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
|
||
@item
|
||
Calculate and draw histogram:
|
||
@example
|
||
ffplay -i input -vf histogram
|
||
@end example
|
||
|
||
@end itemize
|
||
|
||
@anchor{hqdn3d}
|
||
@section hqdn3d
|
||
|
||
This is a high precision/quality 3d denoise filter. It aims to reduce
|
||
image noise, producing smooth images and making still images really
|
||
still. It should enhance compressibility.
|
||
|
||
It accepts the following optional parameters:
|
||
|
||
@table @option
|
||
@item luma_spatial
|
||
A non-negative floating point number which specifies spatial luma strength.
|
||
It defaults to 4.0.
|
||
|
||
@item chroma_spatial
|
||
A non-negative floating point number which specifies spatial chroma strength.
|
||
It defaults to 3.0*@var{luma_spatial}/4.0.
|
||
|
||
@item luma_tmp
|
||
A floating point number which specifies luma temporal strength. It defaults to
|
||
6.0*@var{luma_spatial}/4.0.
|
||
|
||
@item chroma_tmp
|
||
A floating point number which specifies chroma temporal strength. It defaults to
|
||
@var{luma_tmp}*@var{chroma_spatial}/@var{luma_spatial}.
|
||
@end table
|
||
|
||
@section hwdownload
|
||
|
||
Download hardware frames to system memory.
|
||
|
||
The input must be in hardware frames, and the output a non-hardware format.
|
||
Not all formats will be supported on the output - it may be necessary to insert
|
||
an additional @option{format} filter immediately following in the graph to get
|
||
the output in a supported format.
|
||
|
||
@section hwmap
|
||
|
||
Map hardware frames to system memory or to another device.
|
||
|
||
This filter has several different modes of operation; which one is used depends
|
||
on the input and output formats:
|
||
@itemize
|
||
@item
|
||
Hardware frame input, normal frame output
|
||
|
||
Map the input frames to system memory and pass them to the output. If the
|
||
original hardware frame is later required (for example, after overlaying
|
||
something else on part of it), the @option{hwmap} filter can be used again
|
||
in the next mode to retrieve it.
|
||
@item
|
||
Normal frame input, hardware frame output
|
||
|
||
If the input is actually a software-mapped hardware frame, then unmap it -
|
||
that is, return the original hardware frame.
|
||
|
||
Otherwise, a device must be provided. Create new hardware surfaces on that
|
||
device for the output, then map them back to the software format at the input
|
||
and give those frames to the preceding filter. This will then act like the
|
||
@option{hwupload} filter, but may be able to avoid an additional copy when
|
||
the input is already in a compatible format.
|
||
@item
|
||
Hardware frame input and output
|
||
|
||
A device must be supplied for the output, either directly or with the
|
||
@option{derive_device} option. The input and output devices must be of
|
||
different types and compatible - the exact meaning of this is
|
||
system-dependent, but typically it means that they must refer to the same
|
||
underlying hardware context (for example, refer to the same graphics card).
|
||
|
||
If the input frames were originally created on the output device, then unmap
|
||
to retrieve the original frames.
|
||
|
||
Otherwise, map the frames to the output device - create new hardware frames
|
||
on the output corresponding to the frames on the input.
|
||
@end itemize
|
||
|
||
The following additional parameters are accepted:
|
||
|
||
@table @option
|
||
@item mode
|
||
Set the frame mapping mode. Some combination of:
|
||
@table @var
|
||
@item read
|
||
The mapped frame should be readable.
|
||
@item write
|
||
The mapped frame should be writeable.
|
||
@item overwrite
|
||
The mapping will always overwrite the entire frame.
|
||
|
||
This may improve performance in some cases, as the original contents of the
|
||
frame need not be loaded.
|
||
@item direct
|
||
The mapping must not involve any copying.
|
||
|
||
Indirect mappings to copies of frames are created in some cases where either
|
||
direct mapping is not possible or it would have unexpected properties.
|
||
Setting this flag ensures that the mapping is direct and will fail if that is
|
||
not possible.
|
||
@end table
|
||
Defaults to @var{read+write} if not specified.
|
||
|
||
@item derive_device @var{type}
|
||
Rather than using the device supplied at initialisation, instead derive a new
|
||
device of type @var{type} from the device the input frames exist on.
|
||
|
||
@item reverse
|
||
In a hardware to hardware mapping, map in reverse - create frames in the sink
|
||
and map them back to the source. This may be necessary in some cases where
|
||
a mapping in one direction is required but only the opposite direction is
|
||
supported by the devices being used.
|
||
|
||
This option is dangerous - it may break the preceding filter in undefined
|
||
ways if there are any additional constraints on that filter's output.
|
||
Do not use it without fully understanding the implications of its use.
|
||
@end table
|
||
|
||
@section hwupload
|
||
|
||
Upload system memory frames to hardware surfaces.
|
||
|
||
The device to upload to must be supplied when the filter is initialised. If
|
||
using ffmpeg, select the appropriate device with the @option{-filter_hw_device}
|
||
option.
|
||
|
||
@anchor{hwupload_cuda}
|
||
@section hwupload_cuda
|
||
|
||
Upload system memory frames to a CUDA device.
|
||
|
||
It accepts the following optional parameters:
|
||
|
||
@table @option
|
||
@item device
|
||
The number of the CUDA device to use
|
||
@end table
|
||
|
||
@section hqx
|
||
|
||
Apply a high-quality magnification filter designed for pixel art. This filter
|
||
was originally created by Maxim Stepin.
|
||
|
||
It accepts the following option:
|
||
|
||
@table @option
|
||
@item n
|
||
Set the scaling dimension: @code{2} for @code{hq2x}, @code{3} for
|
||
@code{hq3x} and @code{4} for @code{hq4x}.
|
||
Default is @code{3}.
|
||
@end table
|
||
|
||
@section hstack
|
||
Stack input videos horizontally.
|
||
|
||
All streams must be of same pixel format and of same height.
|
||
|
||
Note that this filter is faster than using @ref{overlay} and @ref{pad} filter
|
||
to create same output.
|
||
|
||
The filter accept the following option:
|
||
|
||
@table @option
|
||
@item inputs
|
||
Set number of input streams. Default is 2.
|
||
|
||
@item shortest
|
||
If set to 1, force the output to terminate when the shortest input
|
||
terminates. Default value is 0.
|
||
@end table
|
||
|
||
@section hue
|
||
|
||
Modify the hue and/or the saturation of the input.
|
||
|
||
It accepts the following parameters:
|
||
|
||
@table @option
|
||
@item h
|
||
Specify the hue angle as a number of degrees. It accepts an expression,
|
||
and defaults to "0".
|
||
|
||
@item s
|
||
Specify the saturation in the [-10,10] range. It accepts an expression and
|
||
defaults to "1".
|
||
|
||
@item H
|
||
Specify the hue angle as a number of radians. It accepts an
|
||
expression, and defaults to "0".
|
||
|
||
@item b
|
||
Specify the brightness in the [-10,10] range. It accepts an expression and
|
||
defaults to "0".
|
||
@end table
|
||
|
||
@option{h} and @option{H} are mutually exclusive, and can't be
|
||
specified at the same time.
|
||
|
||
The @option{b}, @option{h}, @option{H} and @option{s} option values are
|
||
expressions containing the following constants:
|
||
|
||
@table @option
|
||
@item n
|
||
frame count of the input frame starting from 0
|
||
|
||
@item pts
|
||
presentation timestamp of the input frame expressed in time base units
|
||
|
||
@item r
|
||
frame rate of the input video, NAN if the input frame rate is unknown
|
||
|
||
@item t
|
||
timestamp expressed in seconds, NAN if the input timestamp is unknown
|
||
|
||
@item tb
|
||
time base of the input video
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Set the hue to 90 degrees and the saturation to 1.0:
|
||
@example
|
||
hue=h=90:s=1
|
||
@end example
|
||
|
||
@item
|
||
Same command but expressing the hue in radians:
|
||
@example
|
||
hue=H=PI/2:s=1
|
||
@end example
|
||
|
||
@item
|
||
Rotate hue and make the saturation swing between 0
|
||
and 2 over a period of 1 second:
|
||
@example
|
||
hue="H=2*PI*t: s=sin(2*PI*t)+1"
|
||
@end example
|
||
|
||
@item
|
||
Apply a 3 seconds saturation fade-in effect starting at 0:
|
||
@example
|
||
hue="s=min(t/3\,1)"
|
||
@end example
|
||
|
||
The general fade-in expression can be written as:
|
||
@example
|
||
hue="s=min(0\, max((t-START)/DURATION\, 1))"
|
||
@end example
|
||
|
||
@item
|
||
Apply a 3 seconds saturation fade-out effect starting at 5 seconds:
|
||
@example
|
||
hue="s=max(0\, min(1\, (8-t)/3))"
|
||
@end example
|
||
|
||
The general fade-out expression can be written as:
|
||
@example
|
||
hue="s=max(0\, min(1\, (START+DURATION-t)/DURATION))"
|
||
@end example
|
||
|
||
@end itemize
|
||
|
||
@subsection Commands
|
||
|
||
This filter supports the following commands:
|
||
@table @option
|
||
@item b
|
||
@item s
|
||
@item h
|
||
@item H
|
||
Modify the hue and/or the saturation and/or brightness of the input video.
|
||
The command accepts the same syntax of the corresponding option.
|
||
|
||
If the specified expression is not valid, it is kept at its current
|
||
value.
|
||
@end table
|
||
|
||
@section hysteresis
|
||
|
||
Grow first stream into second stream by connecting components.
|
||
This makes it possible to build more robust edge masks.
|
||
|
||
This filter accepts the following options:
|
||
|
||
@table @option
|
||
@item planes
|
||
Set which planes will be processed as bitmap, unprocessed planes will be
|
||
copied from first stream.
|
||
By default value 0xf, all planes will be processed.
|
||
|
||
@item threshold
|
||
Set threshold which is used in filtering. If pixel component value is higher than
|
||
this value filter algorithm for connecting components is activated.
|
||
By default value is 0.
|
||
@end table
|
||
|
||
@section idet
|
||
|
||
Detect video interlacing type.
|
||
|
||
This filter tries to detect if the input frames are interlaced, progressive,
|
||
top or bottom field first. It will also try to detect fields that are
|
||
repeated between adjacent frames (a sign of telecine).
|
||
|
||
Single frame detection considers only immediately adjacent frames when classifying each frame.
|
||
Multiple frame detection incorporates the classification history of previous frames.
|
||
|
||
The filter will log these metadata values:
|
||
|
||
@table @option
|
||
@item single.current_frame
|
||
Detected type of current frame using single-frame detection. One of:
|
||
``tff'' (top field first), ``bff'' (bottom field first),
|
||
``progressive'', or ``undetermined''
|
||
|
||
@item single.tff
|
||
Cumulative number of frames detected as top field first using single-frame detection.
|
||
|
||
@item multiple.tff
|
||
Cumulative number of frames detected as top field first using multiple-frame detection.
|
||
|
||
@item single.bff
|
||
Cumulative number of frames detected as bottom field first using single-frame detection.
|
||
|
||
@item multiple.current_frame
|
||
Detected type of current frame using multiple-frame detection. One of:
|
||
``tff'' (top field first), ``bff'' (bottom field first),
|
||
``progressive'', or ``undetermined''
|
||
|
||
@item multiple.bff
|
||
Cumulative number of frames detected as bottom field first using multiple-frame detection.
|
||
|
||
@item single.progressive
|
||
Cumulative number of frames detected as progressive using single-frame detection.
|
||
|
||
@item multiple.progressive
|
||
Cumulative number of frames detected as progressive using multiple-frame detection.
|
||
|
||
@item single.undetermined
|
||
Cumulative number of frames that could not be classified using single-frame detection.
|
||
|
||
@item multiple.undetermined
|
||
Cumulative number of frames that could not be classified using multiple-frame detection.
|
||
|
||
@item repeated.current_frame
|
||
Which field in the current frame is repeated from the last. One of ``neither'', ``top'', or ``bottom''.
|
||
|
||
@item repeated.neither
|
||
Cumulative number of frames with no repeated field.
|
||
|
||
@item repeated.top
|
||
Cumulative number of frames with the top field repeated from the previous frame's top field.
|
||
|
||
@item repeated.bottom
|
||
Cumulative number of frames with the bottom field repeated from the previous frame's bottom field.
|
||
@end table
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item intl_thres
|
||
Set interlacing threshold.
|
||
@item prog_thres
|
||
Set progressive threshold.
|
||
@item rep_thres
|
||
Threshold for repeated field detection.
|
||
@item half_life
|
||
Number of frames after which a given frame's contribution to the
|
||
statistics is halved (i.e., it contributes only 0.5 to its
|
||
classification). The default of 0 means that all frames seen are given
|
||
full weight of 1.0 forever.
|
||
@item analyze_interlaced_flag
|
||
When this is not 0 then idet will use the specified number of frames to determine
|
||
if the interlaced flag is accurate, it will not count undetermined frames.
|
||
If the flag is found to be accurate it will be used without any further
|
||
computations, if it is found to be inaccurate it will be cleared without any
|
||
further computations. This allows inserting the idet filter as a low computational
|
||
method to clean up the interlaced flag
|
||
@end table
|
||
|
||
@section il
|
||
|
||
Deinterleave or interleave fields.
|
||
|
||
This filter allows one to process interlaced images fields without
|
||
deinterlacing them. Deinterleaving splits the input frame into 2
|
||
fields (so called half pictures). Odd lines are moved to the top
|
||
half of the output image, even lines to the bottom half.
|
||
You can process (filter) them independently and then re-interleave them.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item luma_mode, l
|
||
@item chroma_mode, c
|
||
@item alpha_mode, a
|
||
Available values for @var{luma_mode}, @var{chroma_mode} and
|
||
@var{alpha_mode} are:
|
||
|
||
@table @samp
|
||
@item none
|
||
Do nothing.
|
||
|
||
@item deinterleave, d
|
||
Deinterleave fields, placing one above the other.
|
||
|
||
@item interleave, i
|
||
Interleave fields. Reverse the effect of deinterleaving.
|
||
@end table
|
||
Default value is @code{none}.
|
||
|
||
@item luma_swap, ls
|
||
@item chroma_swap, cs
|
||
@item alpha_swap, as
|
||
Swap luma/chroma/alpha fields. Exchange even & odd lines. Default value is @code{0}.
|
||
@end table
|
||
|
||
@section inflate
|
||
|
||
Apply inflate effect to the video.
|
||
|
||
This filter replaces the pixel by the local(3x3) average by taking into account
|
||
only values higher than the pixel.
|
||
|
||
It accepts the following options:
|
||
|
||
@table @option
|
||
@item threshold0
|
||
@item threshold1
|
||
@item threshold2
|
||
@item threshold3
|
||
Limit the maximum change for each plane, default is 65535.
|
||
If 0, plane will remain unchanged.
|
||
@end table
|
||
|
||
@section interlace
|
||
|
||
Simple interlacing filter from progressive contents. This interleaves upper (or
|
||
lower) lines from odd frames with lower (or upper) lines from even frames,
|
||
halving the frame rate and preserving image height.
|
||
|
||
@example
|
||
Original Original New Frame
|
||
Frame 'j' Frame 'j+1' (tff)
|
||
========== =========== ==================
|
||
Line 0 --------------------> Frame 'j' Line 0
|
||
Line 1 Line 1 ----> Frame 'j+1' Line 1
|
||
Line 2 ---------------------> Frame 'j' Line 2
|
||
Line 3 Line 3 ----> Frame 'j+1' Line 3
|
||
... ... ...
|
||
New Frame + 1 will be generated by Frame 'j+2' and Frame 'j+3' and so on
|
||
@end example
|
||
|
||
It accepts the following optional parameters:
|
||
|
||
@table @option
|
||
@item scan
|
||
This determines whether the interlaced frame is taken from the even
|
||
(tff - default) or odd (bff) lines of the progressive frame.
|
||
|
||
@item lowpass
|
||
Vertical lowpass filter to avoid twitter interlacing and
|
||
reduce moire patterns.
|
||
|
||
@table @samp
|
||
@item 0, off
|
||
Disable vertical lowpass filter
|
||
|
||
@item 1, linear
|
||
Enable linear filter (default)
|
||
|
||
@item 2, complex
|
||
Enable complex filter. This will slightly less reduce twitter and moire
|
||
but better retain detail and subjective sharpness impression.
|
||
|
||
@end table
|
||
@end table
|
||
|
||
@section kerndeint
|
||
|
||
Deinterlace input video by applying Donald Graft's adaptive kernel
|
||
deinterling. Work on interlaced parts of a video to produce
|
||
progressive frames.
|
||
|
||
The description of the accepted parameters follows.
|
||
|
||
@table @option
|
||
@item thresh
|
||
Set the threshold which affects the filter's tolerance when
|
||
determining if a pixel line must be processed. It must be an integer
|
||
in the range [0,255] and defaults to 10. A value of 0 will result in
|
||
applying the process on every pixels.
|
||
|
||
@item map
|
||
Paint pixels exceeding the threshold value to white if set to 1.
|
||
Default is 0.
|
||
|
||
@item order
|
||
Set the fields order. Swap fields if set to 1, leave fields alone if
|
||
0. Default is 0.
|
||
|
||
@item sharp
|
||
Enable additional sharpening if set to 1. Default is 0.
|
||
|
||
@item twoway
|
||
Enable twoway sharpening if set to 1. Default is 0.
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Apply default values:
|
||
@example
|
||
kerndeint=thresh=10:map=0:order=0:sharp=0:twoway=0
|
||
@end example
|
||
|
||
@item
|
||
Enable additional sharpening:
|
||
@example
|
||
kerndeint=sharp=1
|
||
@end example
|
||
|
||
@item
|
||
Paint processed pixels in white:
|
||
@example
|
||
kerndeint=map=1
|
||
@end example
|
||
@end itemize
|
||
|
||
@section lenscorrection
|
||
|
||
Correct radial lens distortion
|
||
|
||
This filter can be used to correct for radial distortion as can result from the use
|
||
of wide angle lenses, and thereby re-rectify the image. To find the right parameters
|
||
one can use tools available for example as part of opencv or simply trial-and-error.
|
||
To use opencv use the calibration sample (under samples/cpp) from the opencv sources
|
||
and extract the k1 and k2 coefficients from the resulting matrix.
|
||
|
||
Note that effectively the same filter is available in the open-source tools Krita and
|
||
Digikam from the KDE project.
|
||
|
||
In contrast to the @ref{vignette} filter, which can also be used to compensate lens errors,
|
||
this filter corrects the distortion of the image, whereas @ref{vignette} corrects the
|
||
brightness distribution, so you may want to use both filters together in certain
|
||
cases, though you will have to take care of ordering, i.e. whether vignetting should
|
||
be applied before or after lens correction.
|
||
|
||
@subsection Options
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item cx
|
||
Relative x-coordinate of the focal point of the image, and thereby the center of the
|
||
distortion. This value has a range [0,1] and is expressed as fractions of the image
|
||
width.
|
||
@item cy
|
||
Relative y-coordinate of the focal point of the image, and thereby the center of the
|
||
distortion. This value has a range [0,1] and is expressed as fractions of the image
|
||
height.
|
||
@item k1
|
||
Coefficient of the quadratic correction term. 0.5 means no correction.
|
||
@item k2
|
||
Coefficient of the double quadratic correction term. 0.5 means no correction.
|
||
@end table
|
||
|
||
The formula that generates the correction is:
|
||
|
||
@var{r_src} = @var{r_tgt} * (1 + @var{k1} * (@var{r_tgt} / @var{r_0})^2 + @var{k2} * (@var{r_tgt} / @var{r_0})^4)
|
||
|
||
where @var{r_0} is halve of the image diagonal and @var{r_src} and @var{r_tgt} are the
|
||
distances from the focal point in the source and target images, respectively.
|
||
|
||
@section libvmaf
|
||
|
||
Obtain the average VMAF (Video Multi-Method Assessment Fusion)
|
||
score between two input videos.
|
||
|
||
This filter takes two input videos.
|
||
|
||
Both video inputs must have the same resolution and pixel format for
|
||
this filter to work correctly. Also it assumes that both inputs
|
||
have the same number of frames, which are compared one by one.
|
||
|
||
The obtained average VMAF score is printed through the logging system.
|
||
|
||
It requires Netflix's vmaf library (libvmaf) as a pre-requisite.
|
||
After installing the library it can be enabled using:
|
||
@code{./configure --enable-libvmaf}.
|
||
If no model path is specified it uses the default model: @code{vmaf_v0.6.1.pkl}.
|
||
|
||
On the below examples the input file @file{main.mpg} being processed is
|
||
compared with the reference file @file{ref.mpg}.
|
||
|
||
The filter has following options:
|
||
|
||
@table @option
|
||
@item model_path
|
||
Set the model path which is to be used for SVM.
|
||
Default value: @code{"vmaf_v0.6.1.pkl"}
|
||
|
||
@item log_path
|
||
Set the file path to be used to store logs.
|
||
|
||
@item log_fmt
|
||
Set the format of the log file (xml or json).
|
||
|
||
@item enable_transform
|
||
Enables transform for computing vmaf.
|
||
|
||
@item phone_model
|
||
Invokes the phone model which will generate VMAF scores higher than in the
|
||
regular model, which is more suitable for laptop, TV, etc. viewing conditions.
|
||
|
||
@item psnr
|
||
Enables computing psnr along with vmaf.
|
||
|
||
@item ssim
|
||
Enables computing ssim along with vmaf.
|
||
|
||
@item ms_ssim
|
||
Enables computing ms_ssim along with vmaf.
|
||
|
||
@item pool
|
||
Set the pool method to be used for computing vmaf.
|
||
@end table
|
||
|
||
For example:
|
||
@example
|
||
ffmpeg -i main.mpg -i ref.mpg -lavfi libvmaf -f null -
|
||
@end example
|
||
|
||
Example with options:
|
||
@example
|
||
ffmpeg -i main.mpg -i ref.mpg -lavfi libvmaf="psnr=1:enable-transform=1" -f null -
|
||
@end example
|
||
|
||
@section limiter
|
||
|
||
Limits the pixel components values to the specified range [min, max].
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item min
|
||
Lower bound. Defaults to the lowest allowed value for the input.
|
||
|
||
@item max
|
||
Upper bound. Defaults to the highest allowed value for the input.
|
||
|
||
@item planes
|
||
Specify which planes will be processed. Defaults to all available.
|
||
@end table
|
||
|
||
@section loop
|
||
|
||
Loop video frames.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item loop
|
||
Set the number of loops.
|
||
|
||
@item size
|
||
Set maximal size in number of frames.
|
||
|
||
@item start
|
||
Set first frame of loop.
|
||
@end table
|
||
|
||
@anchor{lut3d}
|
||
@section lut3d
|
||
|
||
Apply a 3D LUT to an input video.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item file
|
||
Set the 3D LUT file name.
|
||
|
||
Currently supported formats:
|
||
@table @samp
|
||
@item 3dl
|
||
AfterEffects
|
||
@item cube
|
||
Iridas
|
||
@item dat
|
||
DaVinci
|
||
@item m3d
|
||
Pandora
|
||
@end table
|
||
@item interp
|
||
Select interpolation mode.
|
||
|
||
Available values are:
|
||
|
||
@table @samp
|
||
@item nearest
|
||
Use values from the nearest defined point.
|
||
@item trilinear
|
||
Interpolate values using the 8 points defining a cube.
|
||
@item tetrahedral
|
||
Interpolate values using a tetrahedron.
|
||
@end table
|
||
@end table
|
||
|
||
@section lumakey
|
||
|
||
Turn certain luma values into transparency.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item threshold
|
||
Set the luma which will be used as base for transparency.
|
||
Default value is @code{0}.
|
||
|
||
@item tolerance
|
||
Set the range of luma values to be keyed out.
|
||
Default value is @code{0}.
|
||
|
||
@item softness
|
||
Set the range of softness. Default value is @code{0}.
|
||
Use this to control gradual transition from zero to full transparency.
|
||
@end table
|
||
|
||
@section lut, lutrgb, lutyuv
|
||
|
||
Compute a look-up table for binding each pixel component input value
|
||
to an output value, and apply it to the input video.
|
||
|
||
@var{lutyuv} applies a lookup table to a YUV input video, @var{lutrgb}
|
||
to an RGB input video.
|
||
|
||
These filters accept the following parameters:
|
||
@table @option
|
||
@item c0
|
||
set first pixel component expression
|
||
@item c1
|
||
set second pixel component expression
|
||
@item c2
|
||
set third pixel component expression
|
||
@item c3
|
||
set fourth pixel component expression, corresponds to the alpha component
|
||
|
||
@item r
|
||
set red component expression
|
||
@item g
|
||
set green component expression
|
||
@item b
|
||
set blue component expression
|
||
@item a
|
||
alpha component expression
|
||
|
||
@item y
|
||
set Y/luminance component expression
|
||
@item u
|
||
set U/Cb component expression
|
||
@item v
|
||
set V/Cr component expression
|
||
@end table
|
||
|
||
Each of them specifies the expression to use for computing the lookup table for
|
||
the corresponding pixel component values.
|
||
|
||
The exact component associated to each of the @var{c*} options depends on the
|
||
format in input.
|
||
|
||
The @var{lut} filter requires either YUV or RGB pixel formats in input,
|
||
@var{lutrgb} requires RGB pixel formats in input, and @var{lutyuv} requires YUV.
|
||
|
||
The expressions can contain the following constants and functions:
|
||
|
||
@table @option
|
||
@item w
|
||
@item h
|
||
The input width and height.
|
||
|
||
@item val
|
||
The input value for the pixel component.
|
||
|
||
@item clipval
|
||
The input value, clipped to the @var{minval}-@var{maxval} range.
|
||
|
||
@item maxval
|
||
The maximum value for the pixel component.
|
||
|
||
@item minval
|
||
The minimum value for the pixel component.
|
||
|
||
@item negval
|
||
The negated value for the pixel component value, clipped to the
|
||
@var{minval}-@var{maxval} range; it corresponds to the expression
|
||
"maxval-clipval+minval".
|
||
|
||
@item clip(val)
|
||
The computed value in @var{val}, clipped to the
|
||
@var{minval}-@var{maxval} range.
|
||
|
||
@item gammaval(gamma)
|
||
The computed gamma correction value of the pixel component value,
|
||
clipped to the @var{minval}-@var{maxval} range. It corresponds to the
|
||
expression
|
||
"pow((clipval-minval)/(maxval-minval)\,@var{gamma})*(maxval-minval)+minval"
|
||
|
||
@end table
|
||
|
||
All expressions default to "val".
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Negate input video:
|
||
@example
|
||
lutrgb="r=maxval+minval-val:g=maxval+minval-val:b=maxval+minval-val"
|
||
lutyuv="y=maxval+minval-val:u=maxval+minval-val:v=maxval+minval-val"
|
||
@end example
|
||
|
||
The above is the same as:
|
||
@example
|
||
lutrgb="r=negval:g=negval:b=negval"
|
||
lutyuv="y=negval:u=negval:v=negval"
|
||
@end example
|
||
|
||
@item
|
||
Negate luminance:
|
||
@example
|
||
lutyuv=y=negval
|
||
@end example
|
||
|
||
@item
|
||
Remove chroma components, turning the video into a graytone image:
|
||
@example
|
||
lutyuv="u=128:v=128"
|
||
@end example
|
||
|
||
@item
|
||
Apply a luma burning effect:
|
||
@example
|
||
lutyuv="y=2*val"
|
||
@end example
|
||
|
||
@item
|
||
Remove green and blue components:
|
||
@example
|
||
lutrgb="g=0:b=0"
|
||
@end example
|
||
|
||
@item
|
||
Set a constant alpha channel value on input:
|
||
@example
|
||
format=rgba,lutrgb=a="maxval-minval/2"
|
||
@end example
|
||
|
||
@item
|
||
Correct luminance gamma by a factor of 0.5:
|
||
@example
|
||
lutyuv=y=gammaval(0.5)
|
||
@end example
|
||
|
||
@item
|
||
Discard least significant bits of luma:
|
||
@example
|
||
lutyuv=y='bitand(val, 128+64+32)'
|
||
@end example
|
||
|
||
@item
|
||
Technicolor like effect:
|
||
@example
|
||
lutyuv=u='(val-maxval/2)*2+maxval/2':v='(val-maxval/2)*2+maxval/2'
|
||
@end example
|
||
@end itemize
|
||
|
||
@section lut2, tlut2
|
||
|
||
The @code{lut2} filter takes two input streams and outputs one
|
||
stream.
|
||
|
||
The @code{tlut2} (time lut2) filter takes two consecutive frames
|
||
from one single stream.
|
||
|
||
This filter accepts the following parameters:
|
||
@table @option
|
||
@item c0
|
||
set first pixel component expression
|
||
@item c1
|
||
set second pixel component expression
|
||
@item c2
|
||
set third pixel component expression
|
||
@item c3
|
||
set fourth pixel component expression, corresponds to the alpha component
|
||
@end table
|
||
|
||
Each of them specifies the expression to use for computing the lookup table for
|
||
the corresponding pixel component values.
|
||
|
||
The exact component associated to each of the @var{c*} options depends on the
|
||
format in inputs.
|
||
|
||
The expressions can contain the following constants:
|
||
|
||
@table @option
|
||
@item w
|
||
@item h
|
||
The input width and height.
|
||
|
||
@item x
|
||
The first input value for the pixel component.
|
||
|
||
@item y
|
||
The second input value for the pixel component.
|
||
|
||
@item bdx
|
||
The first input video bit depth.
|
||
|
||
@item bdy
|
||
The second input video bit depth.
|
||
@end table
|
||
|
||
All expressions default to "x".
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Highlight differences between two RGB video streams:
|
||
@example
|
||
lut2='ifnot(x-y,0,pow(2,bdx)-1):ifnot(x-y,0,pow(2,bdx)-1):ifnot(x-y,0,pow(2,bdx)-1)'
|
||
@end example
|
||
|
||
@item
|
||
Highlight differences between two YUV video streams:
|
||
@example
|
||
lut2='ifnot(x-y,0,pow(2,bdx)-1):ifnot(x-y,pow(2,bdx-1),pow(2,bdx)-1):ifnot(x-y,pow(2,bdx-1),pow(2,bdx)-1)'
|
||
@end example
|
||
|
||
@item
|
||
Show max difference between two video streams:
|
||
@example
|
||
lut2='if(lt(x,y),0,if(gt(x,y),pow(2,bdx)-1,pow(2,bdx-1))):if(lt(x,y),0,if(gt(x,y),pow(2,bdx)-1,pow(2,bdx-1))):if(lt(x,y),0,if(gt(x,y),pow(2,bdx)-1,pow(2,bdx-1)))'
|
||
@end example
|
||
@end itemize
|
||
|
||
@section maskedclamp
|
||
|
||
Clamp the first input stream with the second input and third input stream.
|
||
|
||
Returns the value of first stream to be between second input
|
||
stream - @code{undershoot} and third input stream + @code{overshoot}.
|
||
|
||
This filter accepts the following options:
|
||
@table @option
|
||
@item undershoot
|
||
Default value is @code{0}.
|
||
|
||
@item overshoot
|
||
Default value is @code{0}.
|
||
|
||
@item planes
|
||
Set which planes will be processed as bitmap, unprocessed planes will be
|
||
copied from first stream.
|
||
By default value 0xf, all planes will be processed.
|
||
@end table
|
||
|
||
@section maskedmerge
|
||
|
||
Merge the first input stream with the second input stream using per pixel
|
||
weights in the third input stream.
|
||
|
||
A value of 0 in the third stream pixel component means that pixel component
|
||
from first stream is returned unchanged, while maximum value (eg. 255 for
|
||
8-bit videos) means that pixel component from second stream is returned
|
||
unchanged. Intermediate values define the amount of merging between both
|
||
input stream's pixel components.
|
||
|
||
This filter accepts the following options:
|
||
@table @option
|
||
@item planes
|
||
Set which planes will be processed as bitmap, unprocessed planes will be
|
||
copied from first stream.
|
||
By default value 0xf, all planes will be processed.
|
||
@end table
|
||
|
||
@section mcdeint
|
||
|
||
Apply motion-compensation deinterlacing.
|
||
|
||
It needs one field per frame as input and must thus be used together
|
||
with yadif=1/3 or equivalent.
|
||
|
||
This filter accepts the following options:
|
||
@table @option
|
||
@item mode
|
||
Set the deinterlacing mode.
|
||
|
||
It accepts one of the following values:
|
||
@table @samp
|
||
@item fast
|
||
@item medium
|
||
@item slow
|
||
use iterative motion estimation
|
||
@item extra_slow
|
||
like @samp{slow}, but use multiple reference frames.
|
||
@end table
|
||
Default value is @samp{fast}.
|
||
|
||
@item parity
|
||
Set the picture field parity assumed for the input video. It must be
|
||
one of the following values:
|
||
|
||
@table @samp
|
||
@item 0, tff
|
||
assume top field first
|
||
@item 1, bff
|
||
assume bottom field first
|
||
@end table
|
||
|
||
Default value is @samp{bff}.
|
||
|
||
@item qp
|
||
Set per-block quantization parameter (QP) used by the internal
|
||
encoder.
|
||
|
||
Higher values should result in a smoother motion vector field but less
|
||
optimal individual vectors. Default value is 1.
|
||
@end table
|
||
|
||
@section mergeplanes
|
||
|
||
Merge color channel components from several video streams.
|
||
|
||
The filter accepts up to 4 input streams, and merge selected input
|
||
planes to the output video.
|
||
|
||
This filter accepts the following options:
|
||
@table @option
|
||
@item mapping
|
||
Set input to output plane mapping. Default is @code{0}.
|
||
|
||
The mappings is specified as a bitmap. It should be specified as a
|
||
hexadecimal number in the form 0xAa[Bb[Cc[Dd]]]. 'Aa' describes the
|
||
mapping for the first plane of the output stream. 'A' sets the number of
|
||
the input stream to use (from 0 to 3), and 'a' the plane number of the
|
||
corresponding input to use (from 0 to 3). The rest of the mappings is
|
||
similar, 'Bb' describes the mapping for the output stream second
|
||
plane, 'Cc' describes the mapping for the output stream third plane and
|
||
'Dd' describes the mapping for the output stream fourth plane.
|
||
|
||
@item format
|
||
Set output pixel format. Default is @code{yuva444p}.
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Merge three gray video streams of same width and height into single video stream:
|
||
@example
|
||
[a0][a1][a2]mergeplanes=0x001020:yuv444p
|
||
@end example
|
||
|
||
@item
|
||
Merge 1st yuv444p stream and 2nd gray video stream into yuva444p video stream:
|
||
@example
|
||
[a0][a1]mergeplanes=0x00010210:yuva444p
|
||
@end example
|
||
|
||
@item
|
||
Swap Y and A plane in yuva444p stream:
|
||
@example
|
||
format=yuva444p,mergeplanes=0x03010200:yuva444p
|
||
@end example
|
||
|
||
@item
|
||
Swap U and V plane in yuv420p stream:
|
||
@example
|
||
format=yuv420p,mergeplanes=0x000201:yuv420p
|
||
@end example
|
||
|
||
@item
|
||
Cast a rgb24 clip to yuv444p:
|
||
@example
|
||
format=rgb24,mergeplanes=0x000102:yuv444p
|
||
@end example
|
||
@end itemize
|
||
|
||
@section mestimate
|
||
|
||
Estimate and export motion vectors using block matching algorithms.
|
||
Motion vectors are stored in frame side data to be used by other filters.
|
||
|
||
This filter accepts the following options:
|
||
@table @option
|
||
@item method
|
||
Specify the motion estimation method. Accepts one of the following values:
|
||
|
||
@table @samp
|
||
@item esa
|
||
Exhaustive search algorithm.
|
||
@item tss
|
||
Three step search algorithm.
|
||
@item tdls
|
||
Two dimensional logarithmic search algorithm.
|
||
@item ntss
|
||
New three step search algorithm.
|
||
@item fss
|
||
Four step search algorithm.
|
||
@item ds
|
||
Diamond search algorithm.
|
||
@item hexbs
|
||
Hexagon-based search algorithm.
|
||
@item epzs
|
||
Enhanced predictive zonal search algorithm.
|
||
@item umh
|
||
Uneven multi-hexagon search algorithm.
|
||
@end table
|
||
Default value is @samp{esa}.
|
||
|
||
@item mb_size
|
||
Macroblock size. Default @code{16}.
|
||
|
||
@item search_param
|
||
Search parameter. Default @code{7}.
|
||
@end table
|
||
|
||
@section midequalizer
|
||
|
||
Apply Midway Image Equalization effect using two video streams.
|
||
|
||
Midway Image Equalization adjusts a pair of images to have the same
|
||
histogram, while maintaining their dynamics as much as possible. It's
|
||
useful for e.g. matching exposures from a pair of stereo cameras.
|
||
|
||
This filter has two inputs and one output, which must be of same pixel format, but
|
||
may be of different sizes. The output of filter is first input adjusted with
|
||
midway histogram of both inputs.
|
||
|
||
This filter accepts the following option:
|
||
|
||
@table @option
|
||
@item planes
|
||
Set which planes to process. Default is @code{15}, which is all available planes.
|
||
@end table
|
||
|
||
@section minterpolate
|
||
|
||
Convert the video to specified frame rate using motion interpolation.
|
||
|
||
This filter accepts the following options:
|
||
@table @option
|
||
@item fps
|
||
Specify the output frame rate. This can be rational e.g. @code{60000/1001}. Frames are dropped if @var{fps} is lower than source fps. Default @code{60}.
|
||
|
||
@item mi_mode
|
||
Motion interpolation mode. Following values are accepted:
|
||
@table @samp
|
||
@item dup
|
||
Duplicate previous or next frame for interpolating new ones.
|
||
@item blend
|
||
Blend source frames. Interpolated frame is mean of previous and next frames.
|
||
@item mci
|
||
Motion compensated interpolation. Following options are effective when this mode is selected:
|
||
|
||
@table @samp
|
||
@item mc_mode
|
||
Motion compensation mode. Following values are accepted:
|
||
@table @samp
|
||
@item obmc
|
||
Overlapped block motion compensation.
|
||
@item aobmc
|
||
Adaptive overlapped block motion compensation. Window weighting coefficients are controlled adaptively according to the reliabilities of the neighboring motion vectors to reduce oversmoothing.
|
||
@end table
|
||
Default mode is @samp{obmc}.
|
||
|
||
@item me_mode
|
||
Motion estimation mode. Following values are accepted:
|
||
@table @samp
|
||
@item bidir
|
||
Bidirectional motion estimation. Motion vectors are estimated for each source frame in both forward and backward directions.
|
||
@item bilat
|
||
Bilateral motion estimation. Motion vectors are estimated directly for interpolated frame.
|
||
@end table
|
||
Default mode is @samp{bilat}.
|
||
|
||
@item me
|
||
The algorithm to be used for motion estimation. Following values are accepted:
|
||
@table @samp
|
||
@item esa
|
||
Exhaustive search algorithm.
|
||
@item tss
|
||
Three step search algorithm.
|
||
@item tdls
|
||
Two dimensional logarithmic search algorithm.
|
||
@item ntss
|
||
New three step search algorithm.
|
||
@item fss
|
||
Four step search algorithm.
|
||
@item ds
|
||
Diamond search algorithm.
|
||
@item hexbs
|
||
Hexagon-based search algorithm.
|
||
@item epzs
|
||
Enhanced predictive zonal search algorithm.
|
||
@item umh
|
||
Uneven multi-hexagon search algorithm.
|
||
@end table
|
||
Default algorithm is @samp{epzs}.
|
||
|
||
@item mb_size
|
||
Macroblock size. Default @code{16}.
|
||
|
||
@item search_param
|
||
Motion estimation search parameter. Default @code{32}.
|
||
|
||
@item vsbmc
|
||
Enable variable-size block motion compensation. Motion estimation is applied with smaller block sizes at object boundaries in order to make the them less blur. Default is @code{0} (disabled).
|
||
@end table
|
||
@end table
|
||
|
||
@item scd
|
||
Scene change detection method. Scene change leads motion vectors to be in random direction. Scene change detection replace interpolated frames by duplicate ones. May not be needed for other modes. Following values are accepted:
|
||
@table @samp
|
||
@item none
|
||
Disable scene change detection.
|
||
@item fdiff
|
||
Frame difference. Corresponding pixel values are compared and if it satisfies @var{scd_threshold} scene change is detected.
|
||
@end table
|
||
Default method is @samp{fdiff}.
|
||
|
||
@item scd_threshold
|
||
Scene change detection threshold. Default is @code{5.0}.
|
||
@end table
|
||
|
||
@section mpdecimate
|
||
|
||
Drop frames that do not differ greatly from the previous frame in
|
||
order to reduce frame rate.
|
||
|
||
The main use of this filter is for very-low-bitrate encoding
|
||
(e.g. streaming over dialup modem), but it could in theory be used for
|
||
fixing movies that were inverse-telecined incorrectly.
|
||
|
||
A description of the accepted options follows.
|
||
|
||
@table @option
|
||
@item max
|
||
Set the maximum number of consecutive frames which can be dropped (if
|
||
positive), or the minimum interval between dropped frames (if
|
||
negative). If the value is 0, the frame is dropped unregarding the
|
||
number of previous sequentially dropped frames.
|
||
|
||
Default value is 0.
|
||
|
||
@item hi
|
||
@item lo
|
||
@item frac
|
||
Set the dropping threshold values.
|
||
|
||
Values for @option{hi} and @option{lo} are for 8x8 pixel blocks and
|
||
represent actual pixel value differences, so a threshold of 64
|
||
corresponds to 1 unit of difference for each pixel, or the same spread
|
||
out differently over the block.
|
||
|
||
A frame is a candidate for dropping if no 8x8 blocks differ by more
|
||
than a threshold of @option{hi}, and if no more than @option{frac} blocks (1
|
||
meaning the whole image) differ by more than a threshold of @option{lo}.
|
||
|
||
Default value for @option{hi} is 64*12, default value for @option{lo} is
|
||
64*5, and default value for @option{frac} is 0.33.
|
||
@end table
|
||
|
||
|
||
@section negate
|
||
|
||
Negate input video.
|
||
|
||
It accepts an integer in input; if non-zero it negates the
|
||
alpha component (if available). The default value in input is 0.
|
||
|
||
@section nlmeans
|
||
|
||
Denoise frames using Non-Local Means algorithm.
|
||
|
||
Each pixel is adjusted by looking for other pixels with similar contexts. This
|
||
context similarity is defined by comparing their surrounding patches of size
|
||
@option{p}x@option{p}. Patches are searched in an area of @option{r}x@option{r}
|
||
around the pixel.
|
||
|
||
Note that the research area defines centers for patches, which means some
|
||
patches will be made of pixels outside that research area.
|
||
|
||
The filter accepts the following options.
|
||
|
||
@table @option
|
||
@item s
|
||
Set denoising strength.
|
||
|
||
@item p
|
||
Set patch size.
|
||
|
||
@item pc
|
||
Same as @option{p} but for chroma planes.
|
||
|
||
The default value is @var{0} and means automatic.
|
||
|
||
@item r
|
||
Set research size.
|
||
|
||
@item rc
|
||
Same as @option{r} but for chroma planes.
|
||
|
||
The default value is @var{0} and means automatic.
|
||
@end table
|
||
|
||
@section nnedi
|
||
|
||
Deinterlace video using neural network edge directed interpolation.
|
||
|
||
This filter accepts the following options:
|
||
|
||
@table @option
|
||
@item weights
|
||
Mandatory option, without binary file filter can not work.
|
||
Currently file can be found here:
|
||
https://github.com/dubhater/vapoursynth-nnedi3/blob/master/src/nnedi3_weights.bin
|
||
|
||
@item deint
|
||
Set which frames to deinterlace, by default it is @code{all}.
|
||
Can be @code{all} or @code{interlaced}.
|
||
|
||
@item field
|
||
Set mode of operation.
|
||
|
||
Can be one of the following:
|
||
|
||
@table @samp
|
||
@item af
|
||
Use frame flags, both fields.
|
||
@item a
|
||
Use frame flags, single field.
|
||
@item t
|
||
Use top field only.
|
||
@item b
|
||
Use bottom field only.
|
||
@item tf
|
||
Use both fields, top first.
|
||
@item bf
|
||
Use both fields, bottom first.
|
||
@end table
|
||
|
||
@item planes
|
||
Set which planes to process, by default filter process all frames.
|
||
|
||
@item nsize
|
||
Set size of local neighborhood around each pixel, used by the predictor neural
|
||
network.
|
||
|
||
Can be one of the following:
|
||
|
||
@table @samp
|
||
@item s8x6
|
||
@item s16x6
|
||
@item s32x6
|
||
@item s48x6
|
||
@item s8x4
|
||
@item s16x4
|
||
@item s32x4
|
||
@end table
|
||
|
||
@item nns
|
||
Set the number of neurons in predicctor neural network.
|
||
Can be one of the following:
|
||
|
||
@table @samp
|
||
@item n16
|
||
@item n32
|
||
@item n64
|
||
@item n128
|
||
@item n256
|
||
@end table
|
||
|
||
@item qual
|
||
Controls the number of different neural network predictions that are blended
|
||
together to compute the final output value. Can be @code{fast}, default or
|
||
@code{slow}.
|
||
|
||
@item etype
|
||
Set which set of weights to use in the predictor.
|
||
Can be one of the following:
|
||
|
||
@table @samp
|
||
@item a
|
||
weights trained to minimize absolute error
|
||
@item s
|
||
weights trained to minimize squared error
|
||
@end table
|
||
|
||
@item pscrn
|
||
Controls whether or not the prescreener neural network is used to decide
|
||
which pixels should be processed by the predictor neural network and which
|
||
can be handled by simple cubic interpolation.
|
||
The prescreener is trained to know whether cubic interpolation will be
|
||
sufficient for a pixel or whether it should be predicted by the predictor nn.
|
||
The computational complexity of the prescreener nn is much less than that of
|
||
the predictor nn. Since most pixels can be handled by cubic interpolation,
|
||
using the prescreener generally results in much faster processing.
|
||
The prescreener is pretty accurate, so the difference between using it and not
|
||
using it is almost always unnoticeable.
|
||
|
||
Can be one of the following:
|
||
|
||
@table @samp
|
||
@item none
|
||
@item original
|
||
@item new
|
||
@end table
|
||
|
||
Default is @code{new}.
|
||
|
||
@item fapprox
|
||
Set various debugging flags.
|
||
@end table
|
||
|
||
@section noformat
|
||
|
||
Force libavfilter not to use any of the specified pixel formats for the
|
||
input to the next filter.
|
||
|
||
It accepts the following parameters:
|
||
@table @option
|
||
|
||
@item pix_fmts
|
||
A '|'-separated list of pixel format names, such as
|
||
apix_fmts=yuv420p|monow|rgb24".
|
||
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Force libavfilter to use a format different from @var{yuv420p} for the
|
||
input to the vflip filter:
|
||
@example
|
||
noformat=pix_fmts=yuv420p,vflip
|
||
@end example
|
||
|
||
@item
|
||
Convert the input video to any of the formats not contained in the list:
|
||
@example
|
||
noformat=yuv420p|yuv444p|yuv410p
|
||
@end example
|
||
@end itemize
|
||
|
||
@section noise
|
||
|
||
Add noise on video input frame.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item all_seed
|
||
@item c0_seed
|
||
@item c1_seed
|
||
@item c2_seed
|
||
@item c3_seed
|
||
Set noise seed for specific pixel component or all pixel components in case
|
||
of @var{all_seed}. Default value is @code{123457}.
|
||
|
||
@item all_strength, alls
|
||
@item c0_strength, c0s
|
||
@item c1_strength, c1s
|
||
@item c2_strength, c2s
|
||
@item c3_strength, c3s
|
||
Set noise strength for specific pixel component or all pixel components in case
|
||
@var{all_strength}. Default value is @code{0}. Allowed range is [0, 100].
|
||
|
||
@item all_flags, allf
|
||
@item c0_flags, c0f
|
||
@item c1_flags, c1f
|
||
@item c2_flags, c2f
|
||
@item c3_flags, c3f
|
||
Set pixel component flags or set flags for all components if @var{all_flags}.
|
||
Available values for component flags are:
|
||
@table @samp
|
||
@item a
|
||
averaged temporal noise (smoother)
|
||
@item p
|
||
mix random noise with a (semi)regular pattern
|
||
@item t
|
||
temporal noise (noise pattern changes between frames)
|
||
@item u
|
||
uniform noise (gaussian otherwise)
|
||
@end table
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
Add temporal and uniform noise to input video:
|
||
@example
|
||
noise=alls=20:allf=t+u
|
||
@end example
|
||
|
||
@section null
|
||
|
||
Pass the video source unchanged to the output.
|
||
|
||
@section ocr
|
||
Optical Character Recognition
|
||
|
||
This filter uses Tesseract for optical character recognition.
|
||
|
||
It accepts the following options:
|
||
|
||
@table @option
|
||
@item datapath
|
||
Set datapath to tesseract data. Default is to use whatever was
|
||
set at installation.
|
||
|
||
@item language
|
||
Set language, default is "eng".
|
||
|
||
@item whitelist
|
||
Set character whitelist.
|
||
|
||
@item blacklist
|
||
Set character blacklist.
|
||
@end table
|
||
|
||
The filter exports recognized text as the frame metadata @code{lavfi.ocr.text}.
|
||
|
||
@section ocv
|
||
|
||
Apply a video transform using libopencv.
|
||
|
||
To enable this filter, install the libopencv library and headers and
|
||
configure FFmpeg with @code{--enable-libopencv}.
|
||
|
||
It accepts the following parameters:
|
||
|
||
@table @option
|
||
|
||
@item filter_name
|
||
The name of the libopencv filter to apply.
|
||
|
||
@item filter_params
|
||
The parameters to pass to the libopencv filter. If not specified, the default
|
||
values are assumed.
|
||
|
||
@end table
|
||
|
||
Refer to the official libopencv documentation for more precise
|
||
information:
|
||
@url{http://docs.opencv.org/master/modules/imgproc/doc/filtering.html}
|
||
|
||
Several libopencv filters are supported; see the following subsections.
|
||
|
||
@anchor{dilate}
|
||
@subsection dilate
|
||
|
||
Dilate an image by using a specific structuring element.
|
||
It corresponds to the libopencv function @code{cvDilate}.
|
||
|
||
It accepts the parameters: @var{struct_el}|@var{nb_iterations}.
|
||
|
||
@var{struct_el} represents a structuring element, and has the syntax:
|
||
@var{cols}x@var{rows}+@var{anchor_x}x@var{anchor_y}/@var{shape}
|
||
|
||
@var{cols} and @var{rows} represent the number of columns and rows of
|
||
the structuring element, @var{anchor_x} and @var{anchor_y} the anchor
|
||
point, and @var{shape} the shape for the structuring element. @var{shape}
|
||
must be "rect", "cross", "ellipse", or "custom".
|
||
|
||
If the value for @var{shape} is "custom", it must be followed by a
|
||
string of the form "=@var{filename}". The file with name
|
||
@var{filename} is assumed to represent a binary image, with each
|
||
printable character corresponding to a bright pixel. When a custom
|
||
@var{shape} is used, @var{cols} and @var{rows} are ignored, the number
|
||
or columns and rows of the read file are assumed instead.
|
||
|
||
The default value for @var{struct_el} is "3x3+0x0/rect".
|
||
|
||
@var{nb_iterations} specifies the number of times the transform is
|
||
applied to the image, and defaults to 1.
|
||
|
||
Some examples:
|
||
@example
|
||
# Use the default values
|
||
ocv=dilate
|
||
|
||
# Dilate using a structuring element with a 5x5 cross, iterating two times
|
||
ocv=filter_name=dilate:filter_params=5x5+2x2/cross|2
|
||
|
||
# Read the shape from the file diamond.shape, iterating two times.
|
||
# The file diamond.shape may contain a pattern of characters like this
|
||
# *
|
||
# ***
|
||
# *****
|
||
# ***
|
||
# *
|
||
# The specified columns and rows are ignored
|
||
# but the anchor point coordinates are not
|
||
ocv=dilate:0x0+2x2/custom=diamond.shape|2
|
||
@end example
|
||
|
||
@subsection erode
|
||
|
||
Erode an image by using a specific structuring element.
|
||
It corresponds to the libopencv function @code{cvErode}.
|
||
|
||
It accepts the parameters: @var{struct_el}:@var{nb_iterations},
|
||
with the same syntax and semantics as the @ref{dilate} filter.
|
||
|
||
@subsection smooth
|
||
|
||
Smooth the input video.
|
||
|
||
The filter takes the following parameters:
|
||
@var{type}|@var{param1}|@var{param2}|@var{param3}|@var{param4}.
|
||
|
||
@var{type} is the type of smooth filter to apply, and must be one of
|
||
the following values: "blur", "blur_no_scale", "median", "gaussian",
|
||
or "bilateral". The default value is "gaussian".
|
||
|
||
The meaning of @var{param1}, @var{param2}, @var{param3}, and @var{param4}
|
||
depend on the smooth type. @var{param1} and
|
||
@var{param2} accept integer positive values or 0. @var{param3} and
|
||
@var{param4} accept floating point values.
|
||
|
||
The default value for @var{param1} is 3. The default value for the
|
||
other parameters is 0.
|
||
|
||
These parameters correspond to the parameters assigned to the
|
||
libopencv function @code{cvSmooth}.
|
||
|
||
@section oscilloscope
|
||
|
||
2D Video Oscilloscope.
|
||
|
||
Useful to measure spatial impulse, step responses, chroma delays, etc.
|
||
|
||
It accepts the following parameters:
|
||
|
||
@table @option
|
||
@item x
|
||
Set scope center x position.
|
||
|
||
@item y
|
||
Set scope center y position.
|
||
|
||
@item s
|
||
Set scope size, relative to frame diagonal.
|
||
|
||
@item t
|
||
Set scope tilt/rotation.
|
||
|
||
@item o
|
||
Set trace opacity.
|
||
|
||
@item tx
|
||
Set trace center x position.
|
||
|
||
@item ty
|
||
Set trace center y position.
|
||
|
||
@item tw
|
||
Set trace width, relative to width of frame.
|
||
|
||
@item th
|
||
Set trace height, relative to height of frame.
|
||
|
||
@item c
|
||
Set which components to trace. By default it traces first three components.
|
||
|
||
@item g
|
||
Draw trace grid. By default is enabled.
|
||
|
||
@item st
|
||
Draw some statistics. By default is enabled.
|
||
|
||
@item sc
|
||
Draw scope. By default is enabled.
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Inspect full first row of video frame.
|
||
@example
|
||
oscilloscope=x=0.5:y=0:s=1
|
||
@end example
|
||
|
||
@item
|
||
Inspect full last row of video frame.
|
||
@example
|
||
oscilloscope=x=0.5:y=1:s=1
|
||
@end example
|
||
|
||
@item
|
||
Inspect full 5th line of video frame of height 1080.
|
||
@example
|
||
oscilloscope=x=0.5:y=5/1080:s=1
|
||
@end example
|
||
|
||
@item
|
||
Inspect full last column of video frame.
|
||
@example
|
||
oscilloscope=x=1:y=0.5:s=1:t=1
|
||
@end example
|
||
|
||
@end itemize
|
||
|
||
@anchor{overlay}
|
||
@section overlay
|
||
|
||
Overlay one video on top of another.
|
||
|
||
It takes two inputs and has one output. The first input is the "main"
|
||
video on which the second input is overlaid.
|
||
|
||
It accepts the following parameters:
|
||
|
||
A description of the accepted options follows.
|
||
|
||
@table @option
|
||
@item x
|
||
@item y
|
||
Set the expression for the x and y coordinates of the overlaid video
|
||
on the main video. Default value is "0" for both expressions. In case
|
||
the expression is invalid, it is set to a huge value (meaning that the
|
||
overlay will not be displayed within the output visible area).
|
||
|
||
@item eof_action
|
||
The action to take when EOF is encountered on the secondary input; it accepts
|
||
one of the following values:
|
||
|
||
@table @option
|
||
@item repeat
|
||
Repeat the last frame (the default).
|
||
@item endall
|
||
End both streams.
|
||
@item pass
|
||
Pass the main input through.
|
||
@end table
|
||
|
||
@item eval
|
||
Set when the expressions for @option{x}, and @option{y} are evaluated.
|
||
|
||
It accepts the following values:
|
||
@table @samp
|
||
@item init
|
||
only evaluate expressions once during the filter initialization or
|
||
when a command is processed
|
||
|
||
@item frame
|
||
evaluate expressions for each incoming frame
|
||
@end table
|
||
|
||
Default value is @samp{frame}.
|
||
|
||
@item shortest
|
||
If set to 1, force the output to terminate when the shortest input
|
||
terminates. Default value is 0.
|
||
|
||
@item format
|
||
Set the format for the output video.
|
||
|
||
It accepts the following values:
|
||
@table @samp
|
||
@item yuv420
|
||
force YUV420 output
|
||
|
||
@item yuv422
|
||
force YUV422 output
|
||
|
||
@item yuv444
|
||
force YUV444 output
|
||
|
||
@item rgb
|
||
force packed RGB output
|
||
|
||
@item gbrp
|
||
force planar RGB output
|
||
|
||
@item auto
|
||
automatically pick format
|
||
@end table
|
||
|
||
Default value is @samp{yuv420}.
|
||
|
||
@item repeatlast
|
||
If set to 1, force the filter to draw the last overlay frame over the
|
||
main input until the end of the stream. A value of 0 disables this
|
||
behavior. Default value is 1.
|
||
@end table
|
||
|
||
The @option{x}, and @option{y} expressions can contain the following
|
||
parameters.
|
||
|
||
@table @option
|
||
@item main_w, W
|
||
@item main_h, H
|
||
The main input width and height.
|
||
|
||
@item overlay_w, w
|
||
@item overlay_h, h
|
||
The overlay input width and height.
|
||
|
||
@item x
|
||
@item y
|
||
The computed values for @var{x} and @var{y}. They are evaluated for
|
||
each new frame.
|
||
|
||
@item hsub
|
||
@item vsub
|
||
horizontal and vertical chroma subsample values of the output
|
||
format. For example for the pixel format "yuv422p" @var{hsub} is 2 and
|
||
@var{vsub} is 1.
|
||
|
||
@item n
|
||
the number of input frame, starting from 0
|
||
|
||
@item pos
|
||
the position in the file of the input frame, NAN if unknown
|
||
|
||
@item t
|
||
The timestamp, expressed in seconds. It's NAN if the input timestamp is unknown.
|
||
|
||
@end table
|
||
|
||
Note that the @var{n}, @var{pos}, @var{t} variables are available only
|
||
when evaluation is done @emph{per frame}, and will evaluate to NAN
|
||
when @option{eval} is set to @samp{init}.
|
||
|
||
Be aware that frames are taken from each input video in timestamp
|
||
order, hence, if their initial timestamps differ, it is a good idea
|
||
to pass the two inputs through a @var{setpts=PTS-STARTPTS} filter to
|
||
have them begin in the same zero timestamp, as the example for
|
||
the @var{movie} filter does.
|
||
|
||
You can chain together more overlays but you should test the
|
||
efficiency of such approach.
|
||
|
||
@subsection Commands
|
||
|
||
This filter supports the following commands:
|
||
@table @option
|
||
@item x
|
||
@item y
|
||
Modify the x and y of the overlay input.
|
||
The command accepts the same syntax of the corresponding option.
|
||
|
||
If the specified expression is not valid, it is kept at its current
|
||
value.
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Draw the overlay at 10 pixels from the bottom right corner of the main
|
||
video:
|
||
@example
|
||
overlay=main_w-overlay_w-10:main_h-overlay_h-10
|
||
@end example
|
||
|
||
Using named options the example above becomes:
|
||
@example
|
||
overlay=x=main_w-overlay_w-10:y=main_h-overlay_h-10
|
||
@end example
|
||
|
||
@item
|
||
Insert a transparent PNG logo in the bottom left corner of the input,
|
||
using the @command{ffmpeg} tool with the @code{-filter_complex} option:
|
||
@example
|
||
ffmpeg -i input -i logo -filter_complex 'overlay=10:main_h-overlay_h-10' output
|
||
@end example
|
||
|
||
@item
|
||
Insert 2 different transparent PNG logos (second logo on bottom
|
||
right corner) using the @command{ffmpeg} tool:
|
||
@example
|
||
ffmpeg -i input -i logo1 -i logo2 -filter_complex 'overlay=x=10:y=H-h-10,overlay=x=W-w-10:y=H-h-10' output
|
||
@end example
|
||
|
||
@item
|
||
Add a transparent color layer on top of the main video; @code{WxH}
|
||
must specify the size of the main input to the overlay filter:
|
||
@example
|
||
color=color=red@@.3:size=WxH [over]; [in][over] overlay [out]
|
||
@end example
|
||
|
||
@item
|
||
Play an original video and a filtered version (here with the deshake
|
||
filter) side by side using the @command{ffplay} tool:
|
||
@example
|
||
ffplay input.avi -vf 'split[a][b]; [a]pad=iw*2:ih[src]; [b]deshake[filt]; [src][filt]overlay=w'
|
||
@end example
|
||
|
||
The above command is the same as:
|
||
@example
|
||
ffplay input.avi -vf 'split[b], pad=iw*2[src], [b]deshake, [src]overlay=w'
|
||
@end example
|
||
|
||
@item
|
||
Make a sliding overlay appearing from the left to the right top part of the
|
||
screen starting since time 2:
|
||
@example
|
||
overlay=x='if(gte(t,2), -w+(t-2)*20, NAN)':y=0
|
||
@end example
|
||
|
||
@item
|
||
Compose output by putting two input videos side to side:
|
||
@example
|
||
ffmpeg -i left.avi -i right.avi -filter_complex "
|
||
nullsrc=size=200x100 [background];
|
||
[0:v] setpts=PTS-STARTPTS, scale=100x100 [left];
|
||
[1:v] setpts=PTS-STARTPTS, scale=100x100 [right];
|
||
[background][left] overlay=shortest=1 [background+left];
|
||
[background+left][right] overlay=shortest=1:x=100 [left+right]
|
||
"
|
||
@end example
|
||
|
||
@item
|
||
Mask 10-20 seconds of a video by applying the delogo filter to a section
|
||
@example
|
||
ffmpeg -i test.avi -codec:v:0 wmv2 -ar 11025 -b:v 9000k
|
||
-vf '[in]split[split_main][split_delogo];[split_delogo]trim=start=360:end=371,delogo=0:0:640:480[delogoed];[split_main][delogoed]overlay=eof_action=pass[out]'
|
||
masked.avi
|
||
@end example
|
||
|
||
@item
|
||
Chain several overlays in cascade:
|
||
@example
|
||
nullsrc=s=200x200 [bg];
|
||
testsrc=s=100x100, split=4 [in0][in1][in2][in3];
|
||
[in0] lutrgb=r=0, [bg] overlay=0:0 [mid0];
|
||
[in1] lutrgb=g=0, [mid0] overlay=100:0 [mid1];
|
||
[in2] lutrgb=b=0, [mid1] overlay=0:100 [mid2];
|
||
[in3] null, [mid2] overlay=100:100 [out0]
|
||
@end example
|
||
|
||
@end itemize
|
||
|
||
@section owdenoise
|
||
|
||
Apply Overcomplete Wavelet denoiser.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item depth
|
||
Set depth.
|
||
|
||
Larger depth values will denoise lower frequency components more, but
|
||
slow down filtering.
|
||
|
||
Must be an int in the range 8-16, default is @code{8}.
|
||
|
||
@item luma_strength, ls
|
||
Set luma strength.
|
||
|
||
Must be a double value in the range 0-1000, default is @code{1.0}.
|
||
|
||
@item chroma_strength, cs
|
||
Set chroma strength.
|
||
|
||
Must be a double value in the range 0-1000, default is @code{1.0}.
|
||
@end table
|
||
|
||
@anchor{pad}
|
||
@section pad
|
||
|
||
Add paddings to the input image, and place the original input at the
|
||
provided @var{x}, @var{y} coordinates.
|
||
|
||
It accepts the following parameters:
|
||
|
||
@table @option
|
||
@item width, w
|
||
@item height, h
|
||
Specify an expression for the size of the output image with the
|
||
paddings added. If the value for @var{width} or @var{height} is 0, the
|
||
corresponding input size is used for the output.
|
||
|
||
The @var{width} expression can reference the value set by the
|
||
@var{height} expression, and vice versa.
|
||
|
||
The default value of @var{width} and @var{height} is 0.
|
||
|
||
@item x
|
||
@item y
|
||
Specify the offsets to place the input image at within the padded area,
|
||
with respect to the top/left border of the output image.
|
||
|
||
The @var{x} expression can reference the value set by the @var{y}
|
||
expression, and vice versa.
|
||
|
||
The default value of @var{x} and @var{y} is 0.
|
||
|
||
If @var{x} or @var{y} evaluate to a negative number, they'll be changed
|
||
so the input image is centered on the padded area.
|
||
|
||
@item color
|
||
Specify the color of the padded area. For the syntax of this option,
|
||
check the "Color" section in the ffmpeg-utils manual.
|
||
|
||
The default value of @var{color} is "black".
|
||
|
||
@item eval
|
||
Specify when to evaluate @var{width}, @var{height}, @var{x} and @var{y} expression.
|
||
|
||
It accepts the following values:
|
||
|
||
@table @samp
|
||
@item init
|
||
Only evaluate expressions once during the filter initialization or when
|
||
a command is processed.
|
||
|
||
@item frame
|
||
Evaluate expressions for each incoming frame.
|
||
|
||
@end table
|
||
|
||
Default value is @samp{init}.
|
||
|
||
@item aspect
|
||
Pad to aspect instead to a resolution.
|
||
|
||
@end table
|
||
|
||
The value for the @var{width}, @var{height}, @var{x}, and @var{y}
|
||
options are expressions containing the following constants:
|
||
|
||
@table @option
|
||
@item in_w
|
||
@item in_h
|
||
The input video width and height.
|
||
|
||
@item iw
|
||
@item ih
|
||
These are the same as @var{in_w} and @var{in_h}.
|
||
|
||
@item out_w
|
||
@item out_h
|
||
The output width and height (the size of the padded area), as
|
||
specified by the @var{width} and @var{height} expressions.
|
||
|
||
@item ow
|
||
@item oh
|
||
These are the same as @var{out_w} and @var{out_h}.
|
||
|
||
@item x
|
||
@item y
|
||
The x and y offsets as specified by the @var{x} and @var{y}
|
||
expressions, or NAN if not yet specified.
|
||
|
||
@item a
|
||
same as @var{iw} / @var{ih}
|
||
|
||
@item sar
|
||
input sample aspect ratio
|
||
|
||
@item dar
|
||
input display aspect ratio, it is the same as (@var{iw} / @var{ih}) * @var{sar}
|
||
|
||
@item hsub
|
||
@item vsub
|
||
The horizontal and vertical chroma subsample values. For example for the
|
||
pixel format "yuv422p" @var{hsub} is 2 and @var{vsub} is 1.
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Add paddings with the color "violet" to the input video. The output video
|
||
size is 640x480, and the top-left corner of the input video is placed at
|
||
column 0, row 40
|
||
@example
|
||
pad=640:480:0:40:violet
|
||
@end example
|
||
|
||
The example above is equivalent to the following command:
|
||
@example
|
||
pad=width=640:height=480:x=0:y=40:color=violet
|
||
@end example
|
||
|
||
@item
|
||
Pad the input to get an output with dimensions increased by 3/2,
|
||
and put the input video at the center of the padded area:
|
||
@example
|
||
pad="3/2*iw:3/2*ih:(ow-iw)/2:(oh-ih)/2"
|
||
@end example
|
||
|
||
@item
|
||
Pad the input to get a squared output with size equal to the maximum
|
||
value between the input width and height, and put the input video at
|
||
the center of the padded area:
|
||
@example
|
||
pad="max(iw\,ih):ow:(ow-iw)/2:(oh-ih)/2"
|
||
@end example
|
||
|
||
@item
|
||
Pad the input to get a final w/h ratio of 16:9:
|
||
@example
|
||
pad="ih*16/9:ih:(ow-iw)/2:(oh-ih)/2"
|
||
@end example
|
||
|
||
@item
|
||
In case of anamorphic video, in order to set the output display aspect
|
||
correctly, it is necessary to use @var{sar} in the expression,
|
||
according to the relation:
|
||
@example
|
||
(ih * X / ih) * sar = output_dar
|
||
X = output_dar / sar
|
||
@end example
|
||
|
||
Thus the previous example needs to be modified to:
|
||
@example
|
||
pad="ih*16/9/sar:ih:(ow-iw)/2:(oh-ih)/2"
|
||
@end example
|
||
|
||
@item
|
||
Double the output size and put the input video in the bottom-right
|
||
corner of the output padded area:
|
||
@example
|
||
pad="2*iw:2*ih:ow-iw:oh-ih"
|
||
@end example
|
||
@end itemize
|
||
|
||
@anchor{palettegen}
|
||
@section palettegen
|
||
|
||
Generate one palette for a whole video stream.
|
||
|
||
It accepts the following options:
|
||
|
||
@table @option
|
||
@item max_colors
|
||
Set the maximum number of colors to quantize in the palette.
|
||
Note: the palette will still contain 256 colors; the unused palette entries
|
||
will be black.
|
||
|
||
@item reserve_transparent
|
||
Create a palette of 255 colors maximum and reserve the last one for
|
||
transparency. Reserving the transparency color is useful for GIF optimization.
|
||
If not set, the maximum of colors in the palette will be 256. You probably want
|
||
to disable this option for a standalone image.
|
||
Set by default.
|
||
|
||
@item stats_mode
|
||
Set statistics mode.
|
||
|
||
It accepts the following values:
|
||
@table @samp
|
||
@item full
|
||
Compute full frame histograms.
|
||
@item diff
|
||
Compute histograms only for the part that differs from previous frame. This
|
||
might be relevant to give more importance to the moving part of your input if
|
||
the background is static.
|
||
@item single
|
||
Compute new histogram for each frame.
|
||
@end table
|
||
|
||
Default value is @var{full}.
|
||
@end table
|
||
|
||
The filter also exports the frame metadata @code{lavfi.color_quant_ratio}
|
||
(@code{nb_color_in / nb_color_out}) which you can use to evaluate the degree of
|
||
color quantization of the palette. This information is also visible at
|
||
@var{info} logging level.
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Generate a representative palette of a given video using @command{ffmpeg}:
|
||
@example
|
||
ffmpeg -i input.mkv -vf palettegen palette.png
|
||
@end example
|
||
@end itemize
|
||
|
||
@section paletteuse
|
||
|
||
Use a palette to downsample an input video stream.
|
||
|
||
The filter takes two inputs: one video stream and a palette. The palette must
|
||
be a 256 pixels image.
|
||
|
||
It accepts the following options:
|
||
|
||
@table @option
|
||
@item dither
|
||
Select dithering mode. Available algorithms are:
|
||
@table @samp
|
||
@item bayer
|
||
Ordered 8x8 bayer dithering (deterministic)
|
||
@item heckbert
|
||
Dithering as defined by Paul Heckbert in 1982 (simple error diffusion).
|
||
Note: this dithering is sometimes considered "wrong" and is included as a
|
||
reference.
|
||
@item floyd_steinberg
|
||
Floyd and Steingberg dithering (error diffusion)
|
||
@item sierra2
|
||
Frankie Sierra dithering v2 (error diffusion)
|
||
@item sierra2_4a
|
||
Frankie Sierra dithering v2 "Lite" (error diffusion)
|
||
@end table
|
||
|
||
Default is @var{sierra2_4a}.
|
||
|
||
@item bayer_scale
|
||
When @var{bayer} dithering is selected, this option defines the scale of the
|
||
pattern (how much the crosshatch pattern is visible). A low value means more
|
||
visible pattern for less banding, and higher value means less visible pattern
|
||
at the cost of more banding.
|
||
|
||
The option must be an integer value in the range [0,5]. Default is @var{2}.
|
||
|
||
@item diff_mode
|
||
If set, define the zone to process
|
||
|
||
@table @samp
|
||
@item rectangle
|
||
Only the changing rectangle will be reprocessed. This is similar to GIF
|
||
cropping/offsetting compression mechanism. This option can be useful for speed
|
||
if only a part of the image is changing, and has use cases such as limiting the
|
||
scope of the error diffusal @option{dither} to the rectangle that bounds the
|
||
moving scene (it leads to more deterministic output if the scene doesn't change
|
||
much, and as a result less moving noise and better GIF compression).
|
||
@end table
|
||
|
||
Default is @var{none}.
|
||
|
||
@item new
|
||
Take new palette for each output frame.
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Use a palette (generated for example with @ref{palettegen}) to encode a GIF
|
||
using @command{ffmpeg}:
|
||
@example
|
||
ffmpeg -i input.mkv -i palette.png -lavfi paletteuse output.gif
|
||
@end example
|
||
@end itemize
|
||
|
||
@section perspective
|
||
|
||
Correct perspective of video not recorded perpendicular to the screen.
|
||
|
||
A description of the accepted parameters follows.
|
||
|
||
@table @option
|
||
@item x0
|
||
@item y0
|
||
@item x1
|
||
@item y1
|
||
@item x2
|
||
@item y2
|
||
@item x3
|
||
@item y3
|
||
Set coordinates expression for top left, top right, bottom left and bottom right corners.
|
||
Default values are @code{0:0:W:0:0:H:W:H} with which perspective will remain unchanged.
|
||
If the @code{sense} option is set to @code{source}, then the specified points will be sent
|
||
to the corners of the destination. If the @code{sense} option is set to @code{destination},
|
||
then the corners of the source will be sent to the specified coordinates.
|
||
|
||
The expressions can use the following variables:
|
||
|
||
@table @option
|
||
@item W
|
||
@item H
|
||
the width and height of video frame.
|
||
@item in
|
||
Input frame count.
|
||
@item on
|
||
Output frame count.
|
||
@end table
|
||
|
||
@item interpolation
|
||
Set interpolation for perspective correction.
|
||
|
||
It accepts the following values:
|
||
@table @samp
|
||
@item linear
|
||
@item cubic
|
||
@end table
|
||
|
||
Default value is @samp{linear}.
|
||
|
||
@item sense
|
||
Set interpretation of coordinate options.
|
||
|
||
It accepts the following values:
|
||
@table @samp
|
||
@item 0, source
|
||
|
||
Send point in the source specified by the given coordinates to
|
||
the corners of the destination.
|
||
|
||
@item 1, destination
|
||
|
||
Send the corners of the source to the point in the destination specified
|
||
by the given coordinates.
|
||
|
||
Default value is @samp{source}.
|
||
@end table
|
||
|
||
@item eval
|
||
Set when the expressions for coordinates @option{x0,y0,...x3,y3} are evaluated.
|
||
|
||
It accepts the following values:
|
||
@table @samp
|
||
@item init
|
||
only evaluate expressions once during the filter initialization or
|
||
when a command is processed
|
||
|
||
@item frame
|
||
evaluate expressions for each incoming frame
|
||
@end table
|
||
|
||
Default value is @samp{init}.
|
||
@end table
|
||
|
||
@section phase
|
||
|
||
Delay interlaced video by one field time so that the field order changes.
|
||
|
||
The intended use is to fix PAL movies that have been captured with the
|
||
opposite field order to the film-to-video transfer.
|
||
|
||
A description of the accepted parameters follows.
|
||
|
||
@table @option
|
||
@item mode
|
||
Set phase mode.
|
||
|
||
It accepts the following values:
|
||
@table @samp
|
||
@item t
|
||
Capture field order top-first, transfer bottom-first.
|
||
Filter will delay the bottom field.
|
||
|
||
@item b
|
||
Capture field order bottom-first, transfer top-first.
|
||
Filter will delay the top field.
|
||
|
||
@item p
|
||
Capture and transfer with the same field order. This mode only exists
|
||
for the documentation of the other options to refer to, but if you
|
||
actually select it, the filter will faithfully do nothing.
|
||
|
||
@item a
|
||
Capture field order determined automatically by field flags, transfer
|
||
opposite.
|
||
Filter selects among @samp{t} and @samp{b} modes on a frame by frame
|
||
basis using field flags. If no field information is available,
|
||
then this works just like @samp{u}.
|
||
|
||
@item u
|
||
Capture unknown or varying, transfer opposite.
|
||
Filter selects among @samp{t} and @samp{b} on a frame by frame basis by
|
||
analyzing the images and selecting the alternative that produces best
|
||
match between the fields.
|
||
|
||
@item T
|
||
Capture top-first, transfer unknown or varying.
|
||
Filter selects among @samp{t} and @samp{p} using image analysis.
|
||
|
||
@item B
|
||
Capture bottom-first, transfer unknown or varying.
|
||
Filter selects among @samp{b} and @samp{p} using image analysis.
|
||
|
||
@item A
|
||
Capture determined by field flags, transfer unknown or varying.
|
||
Filter selects among @samp{t}, @samp{b} and @samp{p} using field flags and
|
||
image analysis. If no field information is available, then this works just
|
||
like @samp{U}. This is the default mode.
|
||
|
||
@item U
|
||
Both capture and transfer unknown or varying.
|
||
Filter selects among @samp{t}, @samp{b} and @samp{p} using image analysis only.
|
||
@end table
|
||
@end table
|
||
|
||
@section pixdesctest
|
||
|
||
Pixel format descriptor test filter, mainly useful for internal
|
||
testing. The output video should be equal to the input video.
|
||
|
||
For example:
|
||
@example
|
||
format=monow, pixdesctest
|
||
@end example
|
||
|
||
can be used to test the monowhite pixel format descriptor definition.
|
||
|
||
@section pixscope
|
||
|
||
Display sample values of color channels. Mainly useful for checking color and levels.
|
||
|
||
The filters accept the following options:
|
||
|
||
@table @option
|
||
@item x
|
||
Set scope X position, offset on X axis.
|
||
|
||
@item y
|
||
Set scope Y position, offset on Y axis.
|
||
|
||
@item w
|
||
Set scope width.
|
||
|
||
@item h
|
||
Set scope height.
|
||
|
||
@item o
|
||
Set window opacity. This window also holds statistics about pixel area.
|
||
@end table
|
||
|
||
@section pp
|
||
|
||
Enable the specified chain of postprocessing subfilters using libpostproc. This
|
||
library should be automatically selected with a GPL build (@code{--enable-gpl}).
|
||
Subfilters must be separated by '/' and can be disabled by prepending a '-'.
|
||
Each subfilter and some options have a short and a long name that can be used
|
||
interchangeably, i.e. dr/dering are the same.
|
||
|
||
The filters accept the following options:
|
||
|
||
@table @option
|
||
@item subfilters
|
||
Set postprocessing subfilters string.
|
||
@end table
|
||
|
||
All subfilters share common options to determine their scope:
|
||
|
||
@table @option
|
||
@item a/autoq
|
||
Honor the quality commands for this subfilter.
|
||
|
||
@item c/chrom
|
||
Do chrominance filtering, too (default).
|
||
|
||
@item y/nochrom
|
||
Do luminance filtering only (no chrominance).
|
||
|
||
@item n/noluma
|
||
Do chrominance filtering only (no luminance).
|
||
@end table
|
||
|
||
These options can be appended after the subfilter name, separated by a '|'.
|
||
|
||
Available subfilters are:
|
||
|
||
@table @option
|
||
@item hb/hdeblock[|difference[|flatness]]
|
||
Horizontal deblocking filter
|
||
@table @option
|
||
@item difference
|
||
Difference factor where higher values mean more deblocking (default: @code{32}).
|
||
@item flatness
|
||
Flatness threshold where lower values mean more deblocking (default: @code{39}).
|
||
@end table
|
||
|
||
@item vb/vdeblock[|difference[|flatness]]
|
||
Vertical deblocking filter
|
||
@table @option
|
||
@item difference
|
||
Difference factor where higher values mean more deblocking (default: @code{32}).
|
||
@item flatness
|
||
Flatness threshold where lower values mean more deblocking (default: @code{39}).
|
||
@end table
|
||
|
||
@item ha/hadeblock[|difference[|flatness]]
|
||
Accurate horizontal deblocking filter
|
||
@table @option
|
||
@item difference
|
||
Difference factor where higher values mean more deblocking (default: @code{32}).
|
||
@item flatness
|
||
Flatness threshold where lower values mean more deblocking (default: @code{39}).
|
||
@end table
|
||
|
||
@item va/vadeblock[|difference[|flatness]]
|
||
Accurate vertical deblocking filter
|
||
@table @option
|
||
@item difference
|
||
Difference factor where higher values mean more deblocking (default: @code{32}).
|
||
@item flatness
|
||
Flatness threshold where lower values mean more deblocking (default: @code{39}).
|
||
@end table
|
||
@end table
|
||
|
||
The horizontal and vertical deblocking filters share the difference and
|
||
flatness values so you cannot set different horizontal and vertical
|
||
thresholds.
|
||
|
||
@table @option
|
||
@item h1/x1hdeblock
|
||
Experimental horizontal deblocking filter
|
||
|
||
@item v1/x1vdeblock
|
||
Experimental vertical deblocking filter
|
||
|
||
@item dr/dering
|
||
Deringing filter
|
||
|
||
@item tn/tmpnoise[|threshold1[|threshold2[|threshold3]]], temporal noise reducer
|
||
@table @option
|
||
@item threshold1
|
||
larger -> stronger filtering
|
||
@item threshold2
|
||
larger -> stronger filtering
|
||
@item threshold3
|
||
larger -> stronger filtering
|
||
@end table
|
||
|
||
@item al/autolevels[:f/fullyrange], automatic brightness / contrast correction
|
||
@table @option
|
||
@item f/fullyrange
|
||
Stretch luminance to @code{0-255}.
|
||
@end table
|
||
|
||
@item lb/linblenddeint
|
||
Linear blend deinterlacing filter that deinterlaces the given block by
|
||
filtering all lines with a @code{(1 2 1)} filter.
|
||
|
||
@item li/linipoldeint
|
||
Linear interpolating deinterlacing filter that deinterlaces the given block by
|
||
linearly interpolating every second line.
|
||
|
||
@item ci/cubicipoldeint
|
||
Cubic interpolating deinterlacing filter deinterlaces the given block by
|
||
cubically interpolating every second line.
|
||
|
||
@item md/mediandeint
|
||
Median deinterlacing filter that deinterlaces the given block by applying a
|
||
median filter to every second line.
|
||
|
||
@item fd/ffmpegdeint
|
||
FFmpeg deinterlacing filter that deinterlaces the given block by filtering every
|
||
second line with a @code{(-1 4 2 4 -1)} filter.
|
||
|
||
@item l5/lowpass5
|
||
Vertically applied FIR lowpass deinterlacing filter that deinterlaces the given
|
||
block by filtering all lines with a @code{(-1 2 6 2 -1)} filter.
|
||
|
||
@item fq/forceQuant[|quantizer]
|
||
Overrides the quantizer table from the input with the constant quantizer you
|
||
specify.
|
||
@table @option
|
||
@item quantizer
|
||
Quantizer to use
|
||
@end table
|
||
|
||
@item de/default
|
||
Default pp filter combination (@code{hb|a,vb|a,dr|a})
|
||
|
||
@item fa/fast
|
||
Fast pp filter combination (@code{h1|a,v1|a,dr|a})
|
||
|
||
@item ac
|
||
High quality pp filter combination (@code{ha|a|128|7,va|a,dr|a})
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Apply horizontal and vertical deblocking, deringing and automatic
|
||
brightness/contrast:
|
||
@example
|
||
pp=hb/vb/dr/al
|
||
@end example
|
||
|
||
@item
|
||
Apply default filters without brightness/contrast correction:
|
||
@example
|
||
pp=de/-al
|
||
@end example
|
||
|
||
@item
|
||
Apply default filters and temporal denoiser:
|
||
@example
|
||
pp=default/tmpnoise|1|2|3
|
||
@end example
|
||
|
||
@item
|
||
Apply deblocking on luminance only, and switch vertical deblocking on or off
|
||
automatically depending on available CPU time:
|
||
@example
|
||
pp=hb|y/vb|a
|
||
@end example
|
||
@end itemize
|
||
|
||
@section pp7
|
||
Apply Postprocessing filter 7. It is variant of the @ref{spp} filter,
|
||
similar to spp = 6 with 7 point DCT, where only the center sample is
|
||
used after IDCT.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item qp
|
||
Force a constant quantization parameter. It accepts an integer in range
|
||
0 to 63. If not set, the filter will use the QP from the video stream
|
||
(if available).
|
||
|
||
@item mode
|
||
Set thresholding mode. Available modes are:
|
||
|
||
@table @samp
|
||
@item hard
|
||
Set hard thresholding.
|
||
@item soft
|
||
Set soft thresholding (better de-ringing effect, but likely blurrier).
|
||
@item medium
|
||
Set medium thresholding (good results, default).
|
||
@end table
|
||
@end table
|
||
|
||
@section premultiply
|
||
Apply alpha premultiply effect to input video stream using first plane
|
||
of second stream as alpha.
|
||
|
||
Both streams must have same dimensions and same pixel format.
|
||
|
||
The filter accepts the following option:
|
||
|
||
@table @option
|
||
@item planes
|
||
Set which planes will be processed, unprocessed planes will be copied.
|
||
By default value 0xf, all planes will be processed.
|
||
@end table
|
||
|
||
@section prewitt
|
||
Apply prewitt operator to input video stream.
|
||
|
||
The filter accepts the following option:
|
||
|
||
@table @option
|
||
@item planes
|
||
Set which planes will be processed, unprocessed planes will be copied.
|
||
By default value 0xf, all planes will be processed.
|
||
|
||
@item scale
|
||
Set value which will be multiplied with filtered result.
|
||
|
||
@item delta
|
||
Set value which will be added to filtered result.
|
||
@end table
|
||
|
||
@section psnr
|
||
|
||
Obtain the average, maximum and minimum PSNR (Peak Signal to Noise
|
||
Ratio) between two input videos.
|
||
|
||
This filter takes in input two input videos, the first input is
|
||
considered the "main" source and is passed unchanged to the
|
||
output. The second input is used as a "reference" video for computing
|
||
the PSNR.
|
||
|
||
Both video inputs must have the same resolution and pixel format for
|
||
this filter to work correctly. Also it assumes that both inputs
|
||
have the same number of frames, which are compared one by one.
|
||
|
||
The obtained average PSNR is printed through the logging system.
|
||
|
||
The filter stores the accumulated MSE (mean squared error) of each
|
||
frame, and at the end of the processing it is averaged across all frames
|
||
equally, and the following formula is applied to obtain the PSNR:
|
||
|
||
@example
|
||
PSNR = 10*log10(MAX^2/MSE)
|
||
@end example
|
||
|
||
Where MAX is the average of the maximum values of each component of the
|
||
image.
|
||
|
||
The description of the accepted parameters follows.
|
||
|
||
@table @option
|
||
@item stats_file, f
|
||
If specified the filter will use the named file to save the PSNR of
|
||
each individual frame. When filename equals "-" the data is sent to
|
||
standard output.
|
||
|
||
@item stats_version
|
||
Specifies which version of the stats file format to use. Details of
|
||
each format are written below.
|
||
Default value is 1.
|
||
|
||
@item stats_add_max
|
||
Determines whether the max value is output to the stats log.
|
||
Default value is 0.
|
||
Requires stats_version >= 2. If this is set and stats_version < 2,
|
||
the filter will return an error.
|
||
@end table
|
||
|
||
The file printed if @var{stats_file} is selected, contains a sequence of
|
||
key/value pairs of the form @var{key}:@var{value} for each compared
|
||
couple of frames.
|
||
|
||
If a @var{stats_version} greater than 1 is specified, a header line precedes
|
||
the list of per-frame-pair stats, with key value pairs following the frame
|
||
format with the following parameters:
|
||
|
||
@table @option
|
||
@item psnr_log_version
|
||
The version of the log file format. Will match @var{stats_version}.
|
||
|
||
@item fields
|
||
A comma separated list of the per-frame-pair parameters included in
|
||
the log.
|
||
@end table
|
||
|
||
A description of each shown per-frame-pair parameter follows:
|
||
|
||
@table @option
|
||
@item n
|
||
sequential number of the input frame, starting from 1
|
||
|
||
@item mse_avg
|
||
Mean Square Error pixel-by-pixel average difference of the compared
|
||
frames, averaged over all the image components.
|
||
|
||
@item mse_y, mse_u, mse_v, mse_r, mse_g, mse_g, mse_a
|
||
Mean Square Error pixel-by-pixel average difference of the compared
|
||
frames for the component specified by the suffix.
|
||
|
||
@item psnr_y, psnr_u, psnr_v, psnr_r, psnr_g, psnr_b, psnr_a
|
||
Peak Signal to Noise ratio of the compared frames for the component
|
||
specified by the suffix.
|
||
|
||
@item max_avg, max_y, max_u, max_v
|
||
Maximum allowed value for each channel, and average over all
|
||
channels.
|
||
@end table
|
||
|
||
For example:
|
||
@example
|
||
movie=ref_movie.mpg, setpts=PTS-STARTPTS [main];
|
||
[main][ref] psnr="stats_file=stats.log" [out]
|
||
@end example
|
||
|
||
On this example the input file being processed is compared with the
|
||
reference file @file{ref_movie.mpg}. The PSNR of each individual frame
|
||
is stored in @file{stats.log}.
|
||
|
||
@anchor{pullup}
|
||
@section pullup
|
||
|
||
Pulldown reversal (inverse telecine) filter, capable of handling mixed
|
||
hard-telecine, 24000/1001 fps progressive, and 30000/1001 fps progressive
|
||
content.
|
||
|
||
The pullup filter is designed to take advantage of future context in making
|
||
its decisions. This filter is stateless in the sense that it does not lock
|
||
onto a pattern to follow, but it instead looks forward to the following
|
||
fields in order to identify matches and rebuild progressive frames.
|
||
|
||
To produce content with an even framerate, insert the fps filter after
|
||
pullup, use @code{fps=24000/1001} if the input frame rate is 29.97fps,
|
||
@code{fps=24} for 30fps and the (rare) telecined 25fps input.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item jl
|
||
@item jr
|
||
@item jt
|
||
@item jb
|
||
These options set the amount of "junk" to ignore at the left, right, top, and
|
||
bottom of the image, respectively. Left and right are in units of 8 pixels,
|
||
while top and bottom are in units of 2 lines.
|
||
The default is 8 pixels on each side.
|
||
|
||
@item sb
|
||
Set the strict breaks. Setting this option to 1 will reduce the chances of
|
||
filter generating an occasional mismatched frame, but it may also cause an
|
||
excessive number of frames to be dropped during high motion sequences.
|
||
Conversely, setting it to -1 will make filter match fields more easily.
|
||
This may help processing of video where there is slight blurring between
|
||
the fields, but may also cause there to be interlaced frames in the output.
|
||
Default value is @code{0}.
|
||
|
||
@item mp
|
||
Set the metric plane to use. It accepts the following values:
|
||
@table @samp
|
||
@item l
|
||
Use luma plane.
|
||
|
||
@item u
|
||
Use chroma blue plane.
|
||
|
||
@item v
|
||
Use chroma red plane.
|
||
@end table
|
||
|
||
This option may be set to use chroma plane instead of the default luma plane
|
||
for doing filter's computations. This may improve accuracy on very clean
|
||
source material, but more likely will decrease accuracy, especially if there
|
||
is chroma noise (rainbow effect) or any grayscale video.
|
||
The main purpose of setting @option{mp} to a chroma plane is to reduce CPU
|
||
load and make pullup usable in realtime on slow machines.
|
||
@end table
|
||
|
||
For best results (without duplicated frames in the output file) it is
|
||
necessary to change the output frame rate. For example, to inverse
|
||
telecine NTSC input:
|
||
@example
|
||
ffmpeg -i input -vf pullup -r 24000/1001 ...
|
||
@end example
|
||
|
||
@section qp
|
||
|
||
Change video quantization parameters (QP).
|
||
|
||
The filter accepts the following option:
|
||
|
||
@table @option
|
||
@item qp
|
||
Set expression for quantization parameter.
|
||
@end table
|
||
|
||
The expression is evaluated through the eval API and can contain, among others,
|
||
the following constants:
|
||
|
||
@table @var
|
||
@item known
|
||
1 if index is not 129, 0 otherwise.
|
||
|
||
@item qp
|
||
Sequentional index starting from -129 to 128.
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Some equation like:
|
||
@example
|
||
qp=2+2*sin(PI*qp)
|
||
@end example
|
||
@end itemize
|
||
|
||
@section random
|
||
|
||
Flush video frames from internal cache of frames into a random order.
|
||
No frame is discarded.
|
||
Inspired by @ref{frei0r} nervous filter.
|
||
|
||
@table @option
|
||
@item frames
|
||
Set size in number of frames of internal cache, in range from @code{2} to
|
||
@code{512}. Default is @code{30}.
|
||
|
||
@item seed
|
||
Set seed for random number generator, must be an integer included between
|
||
@code{0} and @code{UINT32_MAX}. If not specified, or if explicitly set to
|
||
less than @code{0}, the filter will try to use a good random seed on a
|
||
best effort basis.
|
||
@end table
|
||
|
||
@section readeia608
|
||
|
||
Read closed captioning (EIA-608) information from the top lines of a video frame.
|
||
|
||
This filter adds frame metadata for @code{lavfi.readeia608.X.cc} and
|
||
@code{lavfi.readeia608.X.line}, where @code{X} is the number of the identified line
|
||
with EIA-608 data (starting from 0). A description of each metadata value follows:
|
||
|
||
@table @option
|
||
@item lavfi.readeia608.X.cc
|
||
The two bytes stored as EIA-608 data (printed in hexadecimal).
|
||
|
||
@item lavfi.readeia608.X.line
|
||
The number of the line on which the EIA-608 data was identified and read.
|
||
@end table
|
||
|
||
This filter accepts the following options:
|
||
|
||
@table @option
|
||
@item scan_min
|
||
Set the line to start scanning for EIA-608 data. Default is @code{0}.
|
||
|
||
@item scan_max
|
||
Set the line to end scanning for EIA-608 data. Default is @code{29}.
|
||
|
||
@item mac
|
||
Set minimal acceptable amplitude change for sync codes detection.
|
||
Default is @code{0.2}. Allowed range is @code{[0.001 - 1]}.
|
||
|
||
@item spw
|
||
Set the ratio of width reserved for sync code detection.
|
||
Default is @code{0.27}. Allowed range is @code{[0.01 - 0.7]}.
|
||
|
||
@item mhd
|
||
Set the max peaks height difference for sync code detection.
|
||
Default is @code{0.1}. Allowed range is @code{[0.0 - 0.5]}.
|
||
|
||
@item mpd
|
||
Set max peaks period difference for sync code detection.
|
||
Default is @code{0.1}. Allowed range is @code{[0.0 - 0.5]}.
|
||
|
||
@item msd
|
||
Set the first two max start code bits differences.
|
||
Default is @code{0.02}. Allowed range is @code{[0.0 - 0.5]}.
|
||
|
||
@item bhd
|
||
Set the minimum ratio of bits height compared to 3rd start code bit.
|
||
Default is @code{0.75}. Allowed range is @code{[0.01 - 1]}.
|
||
|
||
@item th_w
|
||
Set the white color threshold. Default is @code{0.35}. Allowed range is @code{[0.1 - 1]}.
|
||
|
||
@item th_b
|
||
Set the black color threshold. Default is @code{0.15}. Allowed range is @code{[0.0 - 0.5]}.
|
||
|
||
@item chp
|
||
Enable checking the parity bit. In the event of a parity error, the filter will output
|
||
@code{0x00} for that character. Default is false.
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Output a csv with presentation time and the first two lines of identified EIA-608 captioning data.
|
||
@example
|
||
ffprobe -f lavfi -i movie=captioned_video.mov,readeia608 -show_entries frame=pkt_pts_time:frame_tags=lavfi.readeia608.0.cc,lavfi.readeia608.1.cc -of csv
|
||
@end example
|
||
@end itemize
|
||
|
||
@section readvitc
|
||
|
||
Read vertical interval timecode (VITC) information from the top lines of a
|
||
video frame.
|
||
|
||
The filter adds frame metadata key @code{lavfi.readvitc.tc_str} with the
|
||
timecode value, if a valid timecode has been detected. Further metadata key
|
||
@code{lavfi.readvitc.found} is set to 0/1 depending on whether
|
||
timecode data has been found or not.
|
||
|
||
This filter accepts the following options:
|
||
|
||
@table @option
|
||
@item scan_max
|
||
Set the maximum number of lines to scan for VITC data. If the value is set to
|
||
@code{-1} the full video frame is scanned. Default is @code{45}.
|
||
|
||
@item thr_b
|
||
Set the luma threshold for black. Accepts float numbers in the range [0.0,1.0],
|
||
default value is @code{0.2}. The value must be equal or less than @code{thr_w}.
|
||
|
||
@item thr_w
|
||
Set the luma threshold for white. Accepts float numbers in the range [0.0,1.0],
|
||
default value is @code{0.6}. The value must be equal or greater than @code{thr_b}.
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Detect and draw VITC data onto the video frame; if no valid VITC is detected,
|
||
draw @code{--:--:--:--} as a placeholder:
|
||
@example
|
||
ffmpeg -i input.avi -filter:v 'readvitc,drawtext=fontfile=FreeMono.ttf:text=%@{metadata\\:lavfi.readvitc.tc_str\\:--\\\\\\:--\\\\\\:--\\\\\\:--@}:x=(w-tw)/2:y=400-ascent'
|
||
@end example
|
||
@end itemize
|
||
|
||
@section remap
|
||
|
||
Remap pixels using 2nd: Xmap and 3rd: Ymap input video stream.
|
||
|
||
Destination pixel at position (X, Y) will be picked from source (x, y) position
|
||
where x = Xmap(X, Y) and y = Ymap(X, Y). If mapping values are out of range, zero
|
||
value for pixel will be used for destination pixel.
|
||
|
||
Xmap and Ymap input video streams must be of same dimensions. Output video stream
|
||
will have Xmap/Ymap video stream dimensions.
|
||
Xmap and Ymap input video streams are 16bit depth, single channel.
|
||
|
||
@section removegrain
|
||
|
||
The removegrain filter is a spatial denoiser for progressive video.
|
||
|
||
@table @option
|
||
@item m0
|
||
Set mode for the first plane.
|
||
|
||
@item m1
|
||
Set mode for the second plane.
|
||
|
||
@item m2
|
||
Set mode for the third plane.
|
||
|
||
@item m3
|
||
Set mode for the fourth plane.
|
||
@end table
|
||
|
||
Range of mode is from 0 to 24. Description of each mode follows:
|
||
|
||
@table @var
|
||
@item 0
|
||
Leave input plane unchanged. Default.
|
||
|
||
@item 1
|
||
Clips the pixel with the minimum and maximum of the 8 neighbour pixels.
|
||
|
||
@item 2
|
||
Clips the pixel with the second minimum and maximum of the 8 neighbour pixels.
|
||
|
||
@item 3
|
||
Clips the pixel with the third minimum and maximum of the 8 neighbour pixels.
|
||
|
||
@item 4
|
||
Clips the pixel with the fourth minimum and maximum of the 8 neighbour pixels.
|
||
This is equivalent to a median filter.
|
||
|
||
@item 5
|
||
Line-sensitive clipping giving the minimal change.
|
||
|
||
@item 6
|
||
Line-sensitive clipping, intermediate.
|
||
|
||
@item 7
|
||
Line-sensitive clipping, intermediate.
|
||
|
||
@item 8
|
||
Line-sensitive clipping, intermediate.
|
||
|
||
@item 9
|
||
Line-sensitive clipping on a line where the neighbours pixels are the closest.
|
||
|
||
@item 10
|
||
Replaces the target pixel with the closest neighbour.
|
||
|
||
@item 11
|
||
[1 2 1] horizontal and vertical kernel blur.
|
||
|
||
@item 12
|
||
Same as mode 11.
|
||
|
||
@item 13
|
||
Bob mode, interpolates top field from the line where the neighbours
|
||
pixels are the closest.
|
||
|
||
@item 14
|
||
Bob mode, interpolates bottom field from the line where the neighbours
|
||
pixels are the closest.
|
||
|
||
@item 15
|
||
Bob mode, interpolates top field. Same as 13 but with a more complicated
|
||
interpolation formula.
|
||
|
||
@item 16
|
||
Bob mode, interpolates bottom field. Same as 14 but with a more complicated
|
||
interpolation formula.
|
||
|
||
@item 17
|
||
Clips the pixel with the minimum and maximum of respectively the maximum and
|
||
minimum of each pair of opposite neighbour pixels.
|
||
|
||
@item 18
|
||
Line-sensitive clipping using opposite neighbours whose greatest distance from
|
||
the current pixel is minimal.
|
||
|
||
@item 19
|
||
Replaces the pixel with the average of its 8 neighbours.
|
||
|
||
@item 20
|
||
Averages the 9 pixels ([1 1 1] horizontal and vertical blur).
|
||
|
||
@item 21
|
||
Clips pixels using the averages of opposite neighbour.
|
||
|
||
@item 22
|
||
Same as mode 21 but simpler and faster.
|
||
|
||
@item 23
|
||
Small edge and halo removal, but reputed useless.
|
||
|
||
@item 24
|
||
Similar as 23.
|
||
@end table
|
||
|
||
@section removelogo
|
||
|
||
Suppress a TV station logo, using an image file to determine which
|
||
pixels comprise the logo. It works by filling in the pixels that
|
||
comprise the logo with neighboring pixels.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item filename, f
|
||
Set the filter bitmap file, which can be any image format supported by
|
||
libavformat. The width and height of the image file must match those of the
|
||
video stream being processed.
|
||
@end table
|
||
|
||
Pixels in the provided bitmap image with a value of zero are not
|
||
considered part of the logo, non-zero pixels are considered part of
|
||
the logo. If you use white (255) for the logo and black (0) for the
|
||
rest, you will be safe. For making the filter bitmap, it is
|
||
recommended to take a screen capture of a black frame with the logo
|
||
visible, and then using a threshold filter followed by the erode
|
||
filter once or twice.
|
||
|
||
If needed, little splotches can be fixed manually. Remember that if
|
||
logo pixels are not covered, the filter quality will be much
|
||
reduced. Marking too many pixels as part of the logo does not hurt as
|
||
much, but it will increase the amount of blurring needed to cover over
|
||
the image and will destroy more information than necessary, and extra
|
||
pixels will slow things down on a large logo.
|
||
|
||
@section repeatfields
|
||
|
||
This filter uses the repeat_field flag from the Video ES headers and hard repeats
|
||
fields based on its value.
|
||
|
||
@section reverse
|
||
|
||
Reverse a video clip.
|
||
|
||
Warning: This filter requires memory to buffer the entire clip, so trimming
|
||
is suggested.
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Take the first 5 seconds of a clip, and reverse it.
|
||
@example
|
||
trim=end=5,reverse
|
||
@end example
|
||
@end itemize
|
||
|
||
@section roberts
|
||
Apply roberts cross operator to input video stream.
|
||
|
||
The filter accepts the following option:
|
||
|
||
@table @option
|
||
@item planes
|
||
Set which planes will be processed, unprocessed planes will be copied.
|
||
By default value 0xf, all planes will be processed.
|
||
|
||
@item scale
|
||
Set value which will be multiplied with filtered result.
|
||
|
||
@item delta
|
||
Set value which will be added to filtered result.
|
||
@end table
|
||
|
||
@section rotate
|
||
|
||
Rotate video by an arbitrary angle expressed in radians.
|
||
|
||
The filter accepts the following options:
|
||
|
||
A description of the optional parameters follows.
|
||
@table @option
|
||
@item angle, a
|
||
Set an expression for the angle by which to rotate the input video
|
||
clockwise, expressed as a number of radians. A negative value will
|
||
result in a counter-clockwise rotation. By default it is set to "0".
|
||
|
||
This expression is evaluated for each frame.
|
||
|
||
@item out_w, ow
|
||
Set the output width expression, default value is "iw".
|
||
This expression is evaluated just once during configuration.
|
||
|
||
@item out_h, oh
|
||
Set the output height expression, default value is "ih".
|
||
This expression is evaluated just once during configuration.
|
||
|
||
@item bilinear
|
||
Enable bilinear interpolation if set to 1, a value of 0 disables
|
||
it. Default value is 1.
|
||
|
||
@item fillcolor, c
|
||
Set the color used to fill the output area not covered by the rotated
|
||
image. For the general syntax of this option, check the "Color" section in the
|
||
ffmpeg-utils manual. If the special value "none" is selected then no
|
||
background is printed (useful for example if the background is never shown).
|
||
|
||
Default value is "black".
|
||
@end table
|
||
|
||
The expressions for the angle and the output size can contain the
|
||
following constants and functions:
|
||
|
||
@table @option
|
||
@item n
|
||
sequential number of the input frame, starting from 0. It is always NAN
|
||
before the first frame is filtered.
|
||
|
||
@item t
|
||
time in seconds of the input frame, it is set to 0 when the filter is
|
||
configured. It is always NAN before the first frame is filtered.
|
||
|
||
@item hsub
|
||
@item vsub
|
||
horizontal and vertical chroma subsample values. For example for the
|
||
pixel format "yuv422p" @var{hsub} is 2 and @var{vsub} is 1.
|
||
|
||
@item in_w, iw
|
||
@item in_h, ih
|
||
the input video width and height
|
||
|
||
@item out_w, ow
|
||
@item out_h, oh
|
||
the output width and height, that is the size of the padded area as
|
||
specified by the @var{width} and @var{height} expressions
|
||
|
||
@item rotw(a)
|
||
@item roth(a)
|
||
the minimal width/height required for completely containing the input
|
||
video rotated by @var{a} radians.
|
||
|
||
These are only available when computing the @option{out_w} and
|
||
@option{out_h} expressions.
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Rotate the input by PI/6 radians clockwise:
|
||
@example
|
||
rotate=PI/6
|
||
@end example
|
||
|
||
@item
|
||
Rotate the input by PI/6 radians counter-clockwise:
|
||
@example
|
||
rotate=-PI/6
|
||
@end example
|
||
|
||
@item
|
||
Rotate the input by 45 degrees clockwise:
|
||
@example
|
||
rotate=45*PI/180
|
||
@end example
|
||
|
||
@item
|
||
Apply a constant rotation with period T, starting from an angle of PI/3:
|
||
@example
|
||
rotate=PI/3+2*PI*t/T
|
||
@end example
|
||
|
||
@item
|
||
Make the input video rotation oscillating with a period of T
|
||
seconds and an amplitude of A radians:
|
||
@example
|
||
rotate=A*sin(2*PI/T*t)
|
||
@end example
|
||
|
||
@item
|
||
Rotate the video, output size is chosen so that the whole rotating
|
||
input video is always completely contained in the output:
|
||
@example
|
||
rotate='2*PI*t:ow=hypot(iw,ih):oh=ow'
|
||
@end example
|
||
|
||
@item
|
||
Rotate the video, reduce the output size so that no background is ever
|
||
shown:
|
||
@example
|
||
rotate=2*PI*t:ow='min(iw,ih)/sqrt(2)':oh=ow:c=none
|
||
@end example
|
||
@end itemize
|
||
|
||
@subsection Commands
|
||
|
||
The filter supports the following commands:
|
||
|
||
@table @option
|
||
@item a, angle
|
||
Set the angle expression.
|
||
The command accepts the same syntax of the corresponding option.
|
||
|
||
If the specified expression is not valid, it is kept at its current
|
||
value.
|
||
@end table
|
||
|
||
@section sab
|
||
|
||
Apply Shape Adaptive Blur.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item luma_radius, lr
|
||
Set luma blur filter strength, must be a value in range 0.1-4.0, default
|
||
value is 1.0. A greater value will result in a more blurred image, and
|
||
in slower processing.
|
||
|
||
@item luma_pre_filter_radius, lpfr
|
||
Set luma pre-filter radius, must be a value in the 0.1-2.0 range, default
|
||
value is 1.0.
|
||
|
||
@item luma_strength, ls
|
||
Set luma maximum difference between pixels to still be considered, must
|
||
be a value in the 0.1-100.0 range, default value is 1.0.
|
||
|
||
@item chroma_radius, cr
|
||
Set chroma blur filter strength, must be a value in range -0.9-4.0. A
|
||
greater value will result in a more blurred image, and in slower
|
||
processing.
|
||
|
||
@item chroma_pre_filter_radius, cpfr
|
||
Set chroma pre-filter radius, must be a value in the -0.9-2.0 range.
|
||
|
||
@item chroma_strength, cs
|
||
Set chroma maximum difference between pixels to still be considered,
|
||
must be a value in the -0.9-100.0 range.
|
||
@end table
|
||
|
||
Each chroma option value, if not explicitly specified, is set to the
|
||
corresponding luma option value.
|
||
|
||
@anchor{scale}
|
||
@section scale
|
||
|
||
Scale (resize) the input video, using the libswscale library.
|
||
|
||
The scale filter forces the output display aspect ratio to be the same
|
||
of the input, by changing the output sample aspect ratio.
|
||
|
||
If the input image format is different from the format requested by
|
||
the next filter, the scale filter will convert the input to the
|
||
requested format.
|
||
|
||
@subsection Options
|
||
The filter accepts the following options, or any of the options
|
||
supported by the libswscale scaler.
|
||
|
||
See @ref{scaler_options,,the ffmpeg-scaler manual,ffmpeg-scaler} for
|
||
the complete list of scaler options.
|
||
|
||
@table @option
|
||
@item width, w
|
||
@item height, h
|
||
Set the output video dimension expression. Default value is the input
|
||
dimension.
|
||
|
||
If the @var{width} or @var{w} value is 0, the input width is used for
|
||
the output. If the @var{height} or @var{h} value is 0, the input height
|
||
is used for the output.
|
||
|
||
If one and only one of the values is -n with n >= 1, the scale filter
|
||
will use a value that maintains the aspect ratio of the input image,
|
||
calculated from the other specified dimension. After that it will,
|
||
however, make sure that the calculated dimension is divisible by n and
|
||
adjust the value if necessary.
|
||
|
||
If both values are -n with n >= 1, the behavior will be identical to
|
||
both values being set to 0 as previously detailed.
|
||
|
||
See below for the list of accepted constants for use in the dimension
|
||
expression.
|
||
|
||
@item eval
|
||
Specify when to evaluate @var{width} and @var{height} expression. It accepts the following values:
|
||
|
||
@table @samp
|
||
@item init
|
||
Only evaluate expressions once during the filter initialization or when a command is processed.
|
||
|
||
@item frame
|
||
Evaluate expressions for each incoming frame.
|
||
|
||
@end table
|
||
|
||
Default value is @samp{init}.
|
||
|
||
|
||
@item interl
|
||
Set the interlacing mode. It accepts the following values:
|
||
|
||
@table @samp
|
||
@item 1
|
||
Force interlaced aware scaling.
|
||
|
||
@item 0
|
||
Do not apply interlaced scaling.
|
||
|
||
@item -1
|
||
Select interlaced aware scaling depending on whether the source frames
|
||
are flagged as interlaced or not.
|
||
@end table
|
||
|
||
Default value is @samp{0}.
|
||
|
||
@item flags
|
||
Set libswscale scaling flags. See
|
||
@ref{sws_flags,,the ffmpeg-scaler manual,ffmpeg-scaler} for the
|
||
complete list of values. If not explicitly specified the filter applies
|
||
the default flags.
|
||
|
||
|
||
@item param0, param1
|
||
Set libswscale input parameters for scaling algorithms that need them. See
|
||
@ref{sws_params,,the ffmpeg-scaler manual,ffmpeg-scaler} for the
|
||
complete documentation. If not explicitly specified the filter applies
|
||
empty parameters.
|
||
|
||
|
||
|
||
@item size, s
|
||
Set the video size. For the syntax of this option, check the
|
||
@ref{video size syntax,,"Video size" section in the ffmpeg-utils manual,ffmpeg-utils}.
|
||
|
||
@item in_color_matrix
|
||
@item out_color_matrix
|
||
Set in/output YCbCr color space type.
|
||
|
||
This allows the autodetected value to be overridden as well as allows forcing
|
||
a specific value used for the output and encoder.
|
||
|
||
If not specified, the color space type depends on the pixel format.
|
||
|
||
Possible values:
|
||
|
||
@table @samp
|
||
@item auto
|
||
Choose automatically.
|
||
|
||
@item bt709
|
||
Format conforming to International Telecommunication Union (ITU)
|
||
Recommendation BT.709.
|
||
|
||
@item fcc
|
||
Set color space conforming to the United States Federal Communications
|
||
Commission (FCC) Code of Federal Regulations (CFR) Title 47 (2003) 73.682 (a).
|
||
|
||
@item bt601
|
||
Set color space conforming to:
|
||
|
||
@itemize
|
||
@item
|
||
ITU Radiocommunication Sector (ITU-R) Recommendation BT.601
|
||
|
||
@item
|
||
ITU-R Rec. BT.470-6 (1998) Systems B, B1, and G
|
||
|
||
@item
|
||
Society of Motion Picture and Television Engineers (SMPTE) ST 170:2004
|
||
|
||
@end itemize
|
||
|
||
@item smpte240m
|
||
Set color space conforming to SMPTE ST 240:1999.
|
||
@end table
|
||
|
||
@item in_range
|
||
@item out_range
|
||
Set in/output YCbCr sample range.
|
||
|
||
This allows the autodetected value to be overridden as well as allows forcing
|
||
a specific value used for the output and encoder. If not specified, the
|
||
range depends on the pixel format. Possible values:
|
||
|
||
@table @samp
|
||
@item auto
|
||
Choose automatically.
|
||
|
||
@item jpeg/full/pc
|
||
Set full range (0-255 in case of 8-bit luma).
|
||
|
||
@item mpeg/tv
|
||
Set "MPEG" range (16-235 in case of 8-bit luma).
|
||
@end table
|
||
|
||
@item force_original_aspect_ratio
|
||
Enable decreasing or increasing output video width or height if necessary to
|
||
keep the original aspect ratio. Possible values:
|
||
|
||
@table @samp
|
||
@item disable
|
||
Scale the video as specified and disable this feature.
|
||
|
||
@item decrease
|
||
The output video dimensions will automatically be decreased if needed.
|
||
|
||
@item increase
|
||
The output video dimensions will automatically be increased if needed.
|
||
|
||
@end table
|
||
|
||
One useful instance of this option is that when you know a specific device's
|
||
maximum allowed resolution, you can use this to limit the output video to
|
||
that, while retaining the aspect ratio. For example, device A allows
|
||
1280x720 playback, and your video is 1920x800. Using this option (set it to
|
||
decrease) and specifying 1280x720 to the command line makes the output
|
||
1280x533.
|
||
|
||
Please note that this is a different thing than specifying -1 for @option{w}
|
||
or @option{h}, you still need to specify the output resolution for this option
|
||
to work.
|
||
|
||
@end table
|
||
|
||
The values of the @option{w} and @option{h} options are expressions
|
||
containing the following constants:
|
||
|
||
@table @var
|
||
@item in_w
|
||
@item in_h
|
||
The input width and height
|
||
|
||
@item iw
|
||
@item ih
|
||
These are the same as @var{in_w} and @var{in_h}.
|
||
|
||
@item out_w
|
||
@item out_h
|
||
The output (scaled) width and height
|
||
|
||
@item ow
|
||
@item oh
|
||
These are the same as @var{out_w} and @var{out_h}
|
||
|
||
@item a
|
||
The same as @var{iw} / @var{ih}
|
||
|
||
@item sar
|
||
input sample aspect ratio
|
||
|
||
@item dar
|
||
The input display aspect ratio. Calculated from @code{(iw / ih) * sar}.
|
||
|
||
@item hsub
|
||
@item vsub
|
||
horizontal and vertical input chroma subsample values. For example for the
|
||
pixel format "yuv422p" @var{hsub} is 2 and @var{vsub} is 1.
|
||
|
||
@item ohsub
|
||
@item ovsub
|
||
horizontal and vertical output chroma subsample values. For example for the
|
||
pixel format "yuv422p" @var{hsub} is 2 and @var{vsub} is 1.
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Scale the input video to a size of 200x100
|
||
@example
|
||
scale=w=200:h=100
|
||
@end example
|
||
|
||
This is equivalent to:
|
||
@example
|
||
scale=200:100
|
||
@end example
|
||
|
||
or:
|
||
@example
|
||
scale=200x100
|
||
@end example
|
||
|
||
@item
|
||
Specify a size abbreviation for the output size:
|
||
@example
|
||
scale=qcif
|
||
@end example
|
||
|
||
which can also be written as:
|
||
@example
|
||
scale=size=qcif
|
||
@end example
|
||
|
||
@item
|
||
Scale the input to 2x:
|
||
@example
|
||
scale=w=2*iw:h=2*ih
|
||
@end example
|
||
|
||
@item
|
||
The above is the same as:
|
||
@example
|
||
scale=2*in_w:2*in_h
|
||
@end example
|
||
|
||
@item
|
||
Scale the input to 2x with forced interlaced scaling:
|
||
@example
|
||
scale=2*iw:2*ih:interl=1
|
||
@end example
|
||
|
||
@item
|
||
Scale the input to half size:
|
||
@example
|
||
scale=w=iw/2:h=ih/2
|
||
@end example
|
||
|
||
@item
|
||
Increase the width, and set the height to the same size:
|
||
@example
|
||
scale=3/2*iw:ow
|
||
@end example
|
||
|
||
@item
|
||
Seek Greek harmony:
|
||
@example
|
||
scale=iw:1/PHI*iw
|
||
scale=ih*PHI:ih
|
||
@end example
|
||
|
||
@item
|
||
Increase the height, and set the width to 3/2 of the height:
|
||
@example
|
||
scale=w=3/2*oh:h=3/5*ih
|
||
@end example
|
||
|
||
@item
|
||
Increase the size, making the size a multiple of the chroma
|
||
subsample values:
|
||
@example
|
||
scale="trunc(3/2*iw/hsub)*hsub:trunc(3/2*ih/vsub)*vsub"
|
||
@end example
|
||
|
||
@item
|
||
Increase the width to a maximum of 500 pixels,
|
||
keeping the same aspect ratio as the input:
|
||
@example
|
||
scale=w='min(500\, iw*3/2):h=-1'
|
||
@end example
|
||
@end itemize
|
||
|
||
@subsection Commands
|
||
|
||
This filter supports the following commands:
|
||
@table @option
|
||
@item width, w
|
||
@item height, h
|
||
Set the output video dimension expression.
|
||
The command accepts the same syntax of the corresponding option.
|
||
|
||
If the specified expression is not valid, it is kept at its current
|
||
value.
|
||
@end table
|
||
|
||
@section scale_npp
|
||
|
||
Use the NVIDIA Performance Primitives (libnpp) to perform scaling and/or pixel
|
||
format conversion on CUDA video frames. Setting the output width and height
|
||
works in the same way as for the @var{scale} filter.
|
||
|
||
The following additional options are accepted:
|
||
@table @option
|
||
@item format
|
||
The pixel format of the output CUDA frames. If set to the string "same" (the
|
||
default), the input format will be kept. Note that automatic format negotiation
|
||
and conversion is not yet supported for hardware frames
|
||
|
||
@item interp_algo
|
||
The interpolation algorithm used for resizing. One of the following:
|
||
@table @option
|
||
@item nn
|
||
Nearest neighbour.
|
||
|
||
@item linear
|
||
@item cubic
|
||
@item cubic2p_bspline
|
||
2-parameter cubic (B=1, C=0)
|
||
|
||
@item cubic2p_catmullrom
|
||
2-parameter cubic (B=0, C=1/2)
|
||
|
||
@item cubic2p_b05c03
|
||
2-parameter cubic (B=1/2, C=3/10)
|
||
|
||
@item super
|
||
Supersampling
|
||
|
||
@item lanczos
|
||
@end table
|
||
|
||
@end table
|
||
|
||
@section scale2ref
|
||
|
||
Scale (resize) the input video, based on a reference video.
|
||
|
||
See the scale filter for available options, scale2ref supports the same but
|
||
uses the reference video instead of the main input as basis. scale2ref also
|
||
supports the following additional constants for the @option{w} and
|
||
@option{h} options:
|
||
|
||
@table @var
|
||
@item main_w
|
||
@item main_h
|
||
The main input video's width and height
|
||
|
||
@item main_a
|
||
The same as @var{main_w} / @var{main_h}
|
||
|
||
@item main_sar
|
||
The main input video's sample aspect ratio
|
||
|
||
@item main_dar, mdar
|
||
The main input video's display aspect ratio. Calculated from
|
||
@code{(main_w / main_h) * main_sar}.
|
||
|
||
@item main_hsub
|
||
@item main_vsub
|
||
The main input video's horizontal and vertical chroma subsample values.
|
||
For example for the pixel format "yuv422p" @var{hsub} is 2 and @var{vsub}
|
||
is 1.
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Scale a subtitle stream (b) to match the main video (a) in size before overlaying
|
||
@example
|
||
'scale2ref[b][a];[a][b]overlay'
|
||
@end example
|
||
@end itemize
|
||
|
||
@anchor{selectivecolor}
|
||
@section selectivecolor
|
||
|
||
Adjust cyan, magenta, yellow and black (CMYK) to certain ranges of colors (such
|
||
as "reds", "yellows", "greens", "cyans", ...). The adjustment range is defined
|
||
by the "purity" of the color (that is, how saturated it already is).
|
||
|
||
This filter is similar to the Adobe Photoshop Selective Color tool.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item correction_method
|
||
Select color correction method.
|
||
|
||
Available values are:
|
||
@table @samp
|
||
@item absolute
|
||
Specified adjustments are applied "as-is" (added/subtracted to original pixel
|
||
component value).
|
||
@item relative
|
||
Specified adjustments are relative to the original component value.
|
||
@end table
|
||
Default is @code{absolute}.
|
||
@item reds
|
||
Adjustments for red pixels (pixels where the red component is the maximum)
|
||
@item yellows
|
||
Adjustments for yellow pixels (pixels where the blue component is the minimum)
|
||
@item greens
|
||
Adjustments for green pixels (pixels where the green component is the maximum)
|
||
@item cyans
|
||
Adjustments for cyan pixels (pixels where the red component is the minimum)
|
||
@item blues
|
||
Adjustments for blue pixels (pixels where the blue component is the maximum)
|
||
@item magentas
|
||
Adjustments for magenta pixels (pixels where the green component is the minimum)
|
||
@item whites
|
||
Adjustments for white pixels (pixels where all components are greater than 128)
|
||
@item neutrals
|
||
Adjustments for all pixels except pure black and pure white
|
||
@item blacks
|
||
Adjustments for black pixels (pixels where all components are lesser than 128)
|
||
@item psfile
|
||
Specify a Photoshop selective color file (@code{.asv}) to import the settings from.
|
||
@end table
|
||
|
||
All the adjustment settings (@option{reds}, @option{yellows}, ...) accept up to
|
||
4 space separated floating point adjustment values in the [-1,1] range,
|
||
respectively to adjust the amount of cyan, magenta, yellow and black for the
|
||
pixels of its range.
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Increase cyan by 50% and reduce yellow by 33% in every green areas, and
|
||
increase magenta by 27% in blue areas:
|
||
@example
|
||
selectivecolor=greens=.5 0 -.33 0:blues=0 .27
|
||
@end example
|
||
|
||
@item
|
||
Use a Photoshop selective color preset:
|
||
@example
|
||
selectivecolor=psfile=MySelectiveColorPresets/Misty.asv
|
||
@end example
|
||
@end itemize
|
||
|
||
@anchor{separatefields}
|
||
@section separatefields
|
||
|
||
The @code{separatefields} takes a frame-based video input and splits
|
||
each frame into its components fields, producing a new half height clip
|
||
with twice the frame rate and twice the frame count.
|
||
|
||
This filter use field-dominance information in frame to decide which
|
||
of each pair of fields to place first in the output.
|
||
If it gets it wrong use @ref{setfield} filter before @code{separatefields} filter.
|
||
|
||
@section setdar, setsar
|
||
|
||
The @code{setdar} filter sets the Display Aspect Ratio for the filter
|
||
output video.
|
||
|
||
This is done by changing the specified Sample (aka Pixel) Aspect
|
||
Ratio, according to the following equation:
|
||
@example
|
||
@var{DAR} = @var{HORIZONTAL_RESOLUTION} / @var{VERTICAL_RESOLUTION} * @var{SAR}
|
||
@end example
|
||
|
||
Keep in mind that the @code{setdar} filter does not modify the pixel
|
||
dimensions of the video frame. Also, the display aspect ratio set by
|
||
this filter may be changed by later filters in the filterchain,
|
||
e.g. in case of scaling or if another "setdar" or a "setsar" filter is
|
||
applied.
|
||
|
||
The @code{setsar} filter sets the Sample (aka Pixel) Aspect Ratio for
|
||
the filter output video.
|
||
|
||
Note that as a consequence of the application of this filter, the
|
||
output display aspect ratio will change according to the equation
|
||
above.
|
||
|
||
Keep in mind that the sample aspect ratio set by the @code{setsar}
|
||
filter may be changed by later filters in the filterchain, e.g. if
|
||
another "setsar" or a "setdar" filter is applied.
|
||
|
||
It accepts the following parameters:
|
||
|
||
@table @option
|
||
@item r, ratio, dar (@code{setdar} only), sar (@code{setsar} only)
|
||
Set the aspect ratio used by the filter.
|
||
|
||
The parameter can be a floating point number string, an expression, or
|
||
a string of the form @var{num}:@var{den}, where @var{num} and
|
||
@var{den} are the numerator and denominator of the aspect ratio. If
|
||
the parameter is not specified, it is assumed the value "0".
|
||
In case the form "@var{num}:@var{den}" is used, the @code{:} character
|
||
should be escaped.
|
||
|
||
@item max
|
||
Set the maximum integer value to use for expressing numerator and
|
||
denominator when reducing the expressed aspect ratio to a rational.
|
||
Default value is @code{100}.
|
||
|
||
@end table
|
||
|
||
The parameter @var{sar} is an expression containing
|
||
the following constants:
|
||
|
||
@table @option
|
||
@item E, PI, PHI
|
||
These are approximated values for the mathematical constants e
|
||
(Euler's number), pi (Greek pi), and phi (the golden ratio).
|
||
|
||
@item w, h
|
||
The input width and height.
|
||
|
||
@item a
|
||
These are the same as @var{w} / @var{h}.
|
||
|
||
@item sar
|
||
The input sample aspect ratio.
|
||
|
||
@item dar
|
||
The input display aspect ratio. It is the same as
|
||
(@var{w} / @var{h}) * @var{sar}.
|
||
|
||
@item hsub, vsub
|
||
Horizontal and vertical chroma subsample values. For example, for the
|
||
pixel format "yuv422p" @var{hsub} is 2 and @var{vsub} is 1.
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
|
||
@item
|
||
To change the display aspect ratio to 16:9, specify one of the following:
|
||
@example
|
||
setdar=dar=1.77777
|
||
setdar=dar=16/9
|
||
@end example
|
||
|
||
@item
|
||
To change the sample aspect ratio to 10:11, specify:
|
||
@example
|
||
setsar=sar=10/11
|
||
@end example
|
||
|
||
@item
|
||
To set a display aspect ratio of 16:9, and specify a maximum integer value of
|
||
1000 in the aspect ratio reduction, use the command:
|
||
@example
|
||
setdar=ratio=16/9:max=1000
|
||
@end example
|
||
|
||
@end itemize
|
||
|
||
@anchor{setfield}
|
||
@section setfield
|
||
|
||
Force field for the output video frame.
|
||
|
||
The @code{setfield} filter marks the interlace type field for the
|
||
output frames. It does not change the input frame, but only sets the
|
||
corresponding property, which affects how the frame is treated by
|
||
following filters (e.g. @code{fieldorder} or @code{yadif}).
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
|
||
@item mode
|
||
Available values are:
|
||
|
||
@table @samp
|
||
@item auto
|
||
Keep the same field property.
|
||
|
||
@item bff
|
||
Mark the frame as bottom-field-first.
|
||
|
||
@item tff
|
||
Mark the frame as top-field-first.
|
||
|
||
@item prog
|
||
Mark the frame as progressive.
|
||
@end table
|
||
@end table
|
||
|
||
@section showinfo
|
||
|
||
Show a line containing various information for each input video frame.
|
||
The input video is not modified.
|
||
|
||
The shown line contains a sequence of key/value pairs of the form
|
||
@var{key}:@var{value}.
|
||
|
||
The following values are shown in the output:
|
||
|
||
@table @option
|
||
@item n
|
||
The (sequential) number of the input frame, starting from 0.
|
||
|
||
@item pts
|
||
The Presentation TimeStamp of the input frame, expressed as a number of
|
||
time base units. The time base unit depends on the filter input pad.
|
||
|
||
@item pts_time
|
||
The Presentation TimeStamp of the input frame, expressed as a number of
|
||
seconds.
|
||
|
||
@item pos
|
||
The position of the frame in the input stream, or -1 if this information is
|
||
unavailable and/or meaningless (for example in case of synthetic video).
|
||
|
||
@item fmt
|
||
The pixel format name.
|
||
|
||
@item sar
|
||
The sample aspect ratio of the input frame, expressed in the form
|
||
@var{num}/@var{den}.
|
||
|
||
@item s
|
||
The size of the input frame. For the syntax of this option, check the
|
||
@ref{video size syntax,,"Video size" section in the ffmpeg-utils manual,ffmpeg-utils}.
|
||
|
||
@item i
|
||
The type of interlaced mode ("P" for "progressive", "T" for top field first, "B"
|
||
for bottom field first).
|
||
|
||
@item iskey
|
||
This is 1 if the frame is a key frame, 0 otherwise.
|
||
|
||
@item type
|
||
The picture type of the input frame ("I" for an I-frame, "P" for a
|
||
P-frame, "B" for a B-frame, or "?" for an unknown type).
|
||
Also refer to the documentation of the @code{AVPictureType} enum and of
|
||
the @code{av_get_picture_type_char} function defined in
|
||
@file{libavutil/avutil.h}.
|
||
|
||
@item checksum
|
||
The Adler-32 checksum (printed in hexadecimal) of all the planes of the input frame.
|
||
|
||
@item plane_checksum
|
||
The Adler-32 checksum (printed in hexadecimal) of each plane of the input frame,
|
||
expressed in the form "[@var{c0} @var{c1} @var{c2} @var{c3}]".
|
||
@end table
|
||
|
||
@section showpalette
|
||
|
||
Displays the 256 colors palette of each frame. This filter is only relevant for
|
||
@var{pal8} pixel format frames.
|
||
|
||
It accepts the following option:
|
||
|
||
@table @option
|
||
@item s
|
||
Set the size of the box used to represent one palette color entry. Default is
|
||
@code{30} (for a @code{30x30} pixel box).
|
||
@end table
|
||
|
||
@section shuffleframes
|
||
|
||
Reorder and/or duplicate and/or drop video frames.
|
||
|
||
It accepts the following parameters:
|
||
|
||
@table @option
|
||
@item mapping
|
||
Set the destination indexes of input frames.
|
||
This is space or '|' separated list of indexes that maps input frames to output
|
||
frames. Number of indexes also sets maximal value that each index may have.
|
||
'-1' index have special meaning and that is to drop frame.
|
||
@end table
|
||
|
||
The first frame has the index 0. The default is to keep the input unchanged.
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Swap second and third frame of every three frames of the input:
|
||
@example
|
||
ffmpeg -i INPUT -vf "shuffleframes=0 2 1" OUTPUT
|
||
@end example
|
||
|
||
@item
|
||
Swap 10th and 1st frame of every ten frames of the input:
|
||
@example
|
||
ffmpeg -i INPUT -vf "shuffleframes=9 1 2 3 4 5 6 7 8 0" OUTPUT
|
||
@end example
|
||
@end itemize
|
||
|
||
@section shuffleplanes
|
||
|
||
Reorder and/or duplicate video planes.
|
||
|
||
It accepts the following parameters:
|
||
|
||
@table @option
|
||
|
||
@item map0
|
||
The index of the input plane to be used as the first output plane.
|
||
|
||
@item map1
|
||
The index of the input plane to be used as the second output plane.
|
||
|
||
@item map2
|
||
The index of the input plane to be used as the third output plane.
|
||
|
||
@item map3
|
||
The index of the input plane to be used as the fourth output plane.
|
||
|
||
@end table
|
||
|
||
The first plane has the index 0. The default is to keep the input unchanged.
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Swap the second and third planes of the input:
|
||
@example
|
||
ffmpeg -i INPUT -vf shuffleplanes=0:2:1:3 OUTPUT
|
||
@end example
|
||
@end itemize
|
||
|
||
@anchor{signalstats}
|
||
@section signalstats
|
||
Evaluate various visual metrics that assist in determining issues associated
|
||
with the digitization of analog video media.
|
||
|
||
By default the filter will log these metadata values:
|
||
|
||
@table @option
|
||
@item YMIN
|
||
Display the minimal Y value contained within the input frame. Expressed in
|
||
range of [0-255].
|
||
|
||
@item YLOW
|
||
Display the Y value at the 10% percentile within the input frame. Expressed in
|
||
range of [0-255].
|
||
|
||
@item YAVG
|
||
Display the average Y value within the input frame. Expressed in range of
|
||
[0-255].
|
||
|
||
@item YHIGH
|
||
Display the Y value at the 90% percentile within the input frame. Expressed in
|
||
range of [0-255].
|
||
|
||
@item YMAX
|
||
Display the maximum Y value contained within the input frame. Expressed in
|
||
range of [0-255].
|
||
|
||
@item UMIN
|
||
Display the minimal U value contained within the input frame. Expressed in
|
||
range of [0-255].
|
||
|
||
@item ULOW
|
||
Display the U value at the 10% percentile within the input frame. Expressed in
|
||
range of [0-255].
|
||
|
||
@item UAVG
|
||
Display the average U value within the input frame. Expressed in range of
|
||
[0-255].
|
||
|
||
@item UHIGH
|
||
Display the U value at the 90% percentile within the input frame. Expressed in
|
||
range of [0-255].
|
||
|
||
@item UMAX
|
||
Display the maximum U value contained within the input frame. Expressed in
|
||
range of [0-255].
|
||
|
||
@item VMIN
|
||
Display the minimal V value contained within the input frame. Expressed in
|
||
range of [0-255].
|
||
|
||
@item VLOW
|
||
Display the V value at the 10% percentile within the input frame. Expressed in
|
||
range of [0-255].
|
||
|
||
@item VAVG
|
||
Display the average V value within the input frame. Expressed in range of
|
||
[0-255].
|
||
|
||
@item VHIGH
|
||
Display the V value at the 90% percentile within the input frame. Expressed in
|
||
range of [0-255].
|
||
|
||
@item VMAX
|
||
Display the maximum V value contained within the input frame. Expressed in
|
||
range of [0-255].
|
||
|
||
@item SATMIN
|
||
Display the minimal saturation value contained within the input frame.
|
||
Expressed in range of [0-~181.02].
|
||
|
||
@item SATLOW
|
||
Display the saturation value at the 10% percentile within the input frame.
|
||
Expressed in range of [0-~181.02].
|
||
|
||
@item SATAVG
|
||
Display the average saturation value within the input frame. Expressed in range
|
||
of [0-~181.02].
|
||
|
||
@item SATHIGH
|
||
Display the saturation value at the 90% percentile within the input frame.
|
||
Expressed in range of [0-~181.02].
|
||
|
||
@item SATMAX
|
||
Display the maximum saturation value contained within the input frame.
|
||
Expressed in range of [0-~181.02].
|
||
|
||
@item HUEMED
|
||
Display the median value for hue within the input frame. Expressed in range of
|
||
[0-360].
|
||
|
||
@item HUEAVG
|
||
Display the average value for hue within the input frame. Expressed in range of
|
||
[0-360].
|
||
|
||
@item YDIF
|
||
Display the average of sample value difference between all values of the Y
|
||
plane in the current frame and corresponding values of the previous input frame.
|
||
Expressed in range of [0-255].
|
||
|
||
@item UDIF
|
||
Display the average of sample value difference between all values of the U
|
||
plane in the current frame and corresponding values of the previous input frame.
|
||
Expressed in range of [0-255].
|
||
|
||
@item VDIF
|
||
Display the average of sample value difference between all values of the V
|
||
plane in the current frame and corresponding values of the previous input frame.
|
||
Expressed in range of [0-255].
|
||
|
||
@item YBITDEPTH
|
||
Display bit depth of Y plane in current frame.
|
||
Expressed in range of [0-16].
|
||
|
||
@item UBITDEPTH
|
||
Display bit depth of U plane in current frame.
|
||
Expressed in range of [0-16].
|
||
|
||
@item VBITDEPTH
|
||
Display bit depth of V plane in current frame.
|
||
Expressed in range of [0-16].
|
||
@end table
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item stat
|
||
@item out
|
||
|
||
@option{stat} specify an additional form of image analysis.
|
||
@option{out} output video with the specified type of pixel highlighted.
|
||
|
||
Both options accept the following values:
|
||
|
||
@table @samp
|
||
@item tout
|
||
Identify @var{temporal outliers} pixels. A @var{temporal outlier} is a pixel
|
||
unlike the neighboring pixels of the same field. Examples of temporal outliers
|
||
include the results of video dropouts, head clogs, or tape tracking issues.
|
||
|
||
@item vrep
|
||
Identify @var{vertical line repetition}. Vertical line repetition includes
|
||
similar rows of pixels within a frame. In born-digital video vertical line
|
||
repetition is common, but this pattern is uncommon in video digitized from an
|
||
analog source. When it occurs in video that results from the digitization of an
|
||
analog source it can indicate concealment from a dropout compensator.
|
||
|
||
@item brng
|
||
Identify pixels that fall outside of legal broadcast range.
|
||
@end table
|
||
|
||
@item color, c
|
||
Set the highlight color for the @option{out} option. The default color is
|
||
yellow.
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Output data of various video metrics:
|
||
@example
|
||
ffprobe -f lavfi movie=example.mov,signalstats="stat=tout+vrep+brng" -show_frames
|
||
@end example
|
||
|
||
@item
|
||
Output specific data about the minimum and maximum values of the Y plane per frame:
|
||
@example
|
||
ffprobe -f lavfi movie=example.mov,signalstats -show_entries frame_tags=lavfi.signalstats.YMAX,lavfi.signalstats.YMIN
|
||
@end example
|
||
|
||
@item
|
||
Playback video while highlighting pixels that are outside of broadcast range in red.
|
||
@example
|
||
ffplay example.mov -vf signalstats="out=brng:color=red"
|
||
@end example
|
||
|
||
@item
|
||
Playback video with signalstats metadata drawn over the frame.
|
||
@example
|
||
ffplay example.mov -vf signalstats=stat=brng+vrep+tout,drawtext=fontfile=FreeSerif.ttf:textfile=signalstat_drawtext.txt
|
||
@end example
|
||
|
||
The contents of signalstat_drawtext.txt used in the command are:
|
||
@example
|
||
time %@{pts:hms@}
|
||
Y (%@{metadata:lavfi.signalstats.YMIN@}-%@{metadata:lavfi.signalstats.YMAX@})
|
||
U (%@{metadata:lavfi.signalstats.UMIN@}-%@{metadata:lavfi.signalstats.UMAX@})
|
||
V (%@{metadata:lavfi.signalstats.VMIN@}-%@{metadata:lavfi.signalstats.VMAX@})
|
||
saturation maximum: %@{metadata:lavfi.signalstats.SATMAX@}
|
||
|
||
@end example
|
||
@end itemize
|
||
|
||
@anchor{signature}
|
||
@section signature
|
||
|
||
Calculates the MPEG-7 Video Signature. The filter can handle more than one
|
||
input. In this case the matching between the inputs can be calculated additionally.
|
||
The filter always passes through the first input. The signature of each stream can
|
||
be written into a file.
|
||
|
||
It accepts the following options:
|
||
|
||
@table @option
|
||
@item detectmode
|
||
Enable or disable the matching process.
|
||
|
||
Available values are:
|
||
|
||
@table @samp
|
||
@item off
|
||
Disable the calculation of a matching (default).
|
||
@item full
|
||
Calculate the matching for the whole video and output whether the whole video
|
||
matches or only parts.
|
||
@item fast
|
||
Calculate only until a matching is found or the video ends. Should be faster in
|
||
some cases.
|
||
@end table
|
||
|
||
@item nb_inputs
|
||
Set the number of inputs. The option value must be a non negative integer.
|
||
Default value is 1.
|
||
|
||
@item filename
|
||
Set the path to which the output is written. If there is more than one input,
|
||
the path must be a prototype, i.e. must contain %d or %0nd (where n is a positive
|
||
integer), that will be replaced with the input number. If no filename is
|
||
specified, no output will be written. This is the default.
|
||
|
||
@item format
|
||
Choose the output format.
|
||
|
||
Available values are:
|
||
|
||
@table @samp
|
||
@item binary
|
||
Use the specified binary representation (default).
|
||
@item xml
|
||
Use the specified xml representation.
|
||
@end table
|
||
|
||
@item th_d
|
||
Set threshold to detect one word as similar. The option value must be an integer
|
||
greater than zero. The default value is 9000.
|
||
|
||
@item th_dc
|
||
Set threshold to detect all words as similar. The option value must be an integer
|
||
greater than zero. The default value is 60000.
|
||
|
||
@item th_xh
|
||
Set threshold to detect frames as similar. The option value must be an integer
|
||
greater than zero. The default value is 116.
|
||
|
||
@item th_di
|
||
Set the minimum length of a sequence in frames to recognize it as matching
|
||
sequence. The option value must be a non negative integer value.
|
||
The default value is 0.
|
||
|
||
@item th_it
|
||
Set the minimum relation, that matching frames to all frames must have.
|
||
The option value must be a double value between 0 and 1. The default value is 0.5.
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
To calculate the signature of an input video and store it in signature.bin:
|
||
@example
|
||
ffmpeg -i input.mkv -vf signature=filename=signature.bin -map 0:v -f null -
|
||
@end example
|
||
|
||
@item
|
||
To detect whether two videos match and store the signatures in XML format in
|
||
signature0.xml and signature1.xml:
|
||
@example
|
||
ffmpeg -i input1.mkv -i input2.mkv -filter_complex "[0:v][1:v] signature=nb_inputs=2:detectmode=full:format=xml:filename=signature%d.xml" -map :v -f null -
|
||
@end example
|
||
|
||
@end itemize
|
||
|
||
@anchor{smartblur}
|
||
@section smartblur
|
||
|
||
Blur the input video without impacting the outlines.
|
||
|
||
It accepts the following options:
|
||
|
||
@table @option
|
||
@item luma_radius, lr
|
||
Set the luma radius. The option value must be a float number in
|
||
the range [0.1,5.0] that specifies the variance of the gaussian filter
|
||
used to blur the image (slower if larger). Default value is 1.0.
|
||
|
||
@item luma_strength, ls
|
||
Set the luma strength. The option value must be a float number
|
||
in the range [-1.0,1.0] that configures the blurring. A value included
|
||
in [0.0,1.0] will blur the image whereas a value included in
|
||
[-1.0,0.0] will sharpen the image. Default value is 1.0.
|
||
|
||
@item luma_threshold, lt
|
||
Set the luma threshold used as a coefficient to determine
|
||
whether a pixel should be blurred or not. The option value must be an
|
||
integer in the range [-30,30]. A value of 0 will filter all the image,
|
||
a value included in [0,30] will filter flat areas and a value included
|
||
in [-30,0] will filter edges. Default value is 0.
|
||
|
||
@item chroma_radius, cr
|
||
Set the chroma radius. The option value must be a float number in
|
||
the range [0.1,5.0] that specifies the variance of the gaussian filter
|
||
used to blur the image (slower if larger). Default value is @option{luma_radius}.
|
||
|
||
@item chroma_strength, cs
|
||
Set the chroma strength. The option value must be a float number
|
||
in the range [-1.0,1.0] that configures the blurring. A value included
|
||
in [0.0,1.0] will blur the image whereas a value included in
|
||
[-1.0,0.0] will sharpen the image. Default value is @option{luma_strength}.
|
||
|
||
@item chroma_threshold, ct
|
||
Set the chroma threshold used as a coefficient to determine
|
||
whether a pixel should be blurred or not. The option value must be an
|
||
integer in the range [-30,30]. A value of 0 will filter all the image,
|
||
a value included in [0,30] will filter flat areas and a value included
|
||
in [-30,0] will filter edges. Default value is @option{luma_threshold}.
|
||
@end table
|
||
|
||
If a chroma option is not explicitly set, the corresponding luma value
|
||
is set.
|
||
|
||
@section ssim
|
||
|
||
Obtain the SSIM (Structural SImilarity Metric) between two input videos.
|
||
|
||
This filter takes in input two input videos, the first input is
|
||
considered the "main" source and is passed unchanged to the
|
||
output. The second input is used as a "reference" video for computing
|
||
the SSIM.
|
||
|
||
Both video inputs must have the same resolution and pixel format for
|
||
this filter to work correctly. Also it assumes that both inputs
|
||
have the same number of frames, which are compared one by one.
|
||
|
||
The filter stores the calculated SSIM of each frame.
|
||
|
||
The description of the accepted parameters follows.
|
||
|
||
@table @option
|
||
@item stats_file, f
|
||
If specified the filter will use the named file to save the SSIM of
|
||
each individual frame. When filename equals "-" the data is sent to
|
||
standard output.
|
||
@end table
|
||
|
||
The file printed if @var{stats_file} is selected, contains a sequence of
|
||
key/value pairs of the form @var{key}:@var{value} for each compared
|
||
couple of frames.
|
||
|
||
A description of each shown parameter follows:
|
||
|
||
@table @option
|
||
@item n
|
||
sequential number of the input frame, starting from 1
|
||
|
||
@item Y, U, V, R, G, B
|
||
SSIM of the compared frames for the component specified by the suffix.
|
||
|
||
@item All
|
||
SSIM of the compared frames for the whole frame.
|
||
|
||
@item dB
|
||
Same as above but in dB representation.
|
||
@end table
|
||
|
||
For example:
|
||
@example
|
||
movie=ref_movie.mpg, setpts=PTS-STARTPTS [main];
|
||
[main][ref] ssim="stats_file=stats.log" [out]
|
||
@end example
|
||
|
||
On this example the input file being processed is compared with the
|
||
reference file @file{ref_movie.mpg}. The SSIM of each individual frame
|
||
is stored in @file{stats.log}.
|
||
|
||
Another example with both psnr and ssim at same time:
|
||
@example
|
||
ffmpeg -i main.mpg -i ref.mpg -lavfi "ssim;[0:v][1:v]psnr" -f null -
|
||
@end example
|
||
|
||
@section stereo3d
|
||
|
||
Convert between different stereoscopic image formats.
|
||
|
||
The filters accept the following options:
|
||
|
||
@table @option
|
||
@item in
|
||
Set stereoscopic image format of input.
|
||
|
||
Available values for input image formats are:
|
||
@table @samp
|
||
@item sbsl
|
||
side by side parallel (left eye left, right eye right)
|
||
|
||
@item sbsr
|
||
side by side crosseye (right eye left, left eye right)
|
||
|
||
@item sbs2l
|
||
side by side parallel with half width resolution
|
||
(left eye left, right eye right)
|
||
|
||
@item sbs2r
|
||
side by side crosseye with half width resolution
|
||
(right eye left, left eye right)
|
||
|
||
@item abl
|
||
above-below (left eye above, right eye below)
|
||
|
||
@item abr
|
||
above-below (right eye above, left eye below)
|
||
|
||
@item ab2l
|
||
above-below with half height resolution
|
||
(left eye above, right eye below)
|
||
|
||
@item ab2r
|
||
above-below with half height resolution
|
||
(right eye above, left eye below)
|
||
|
||
@item al
|
||
alternating frames (left eye first, right eye second)
|
||
|
||
@item ar
|
||
alternating frames (right eye first, left eye second)
|
||
|
||
@item irl
|
||
interleaved rows (left eye has top row, right eye starts on next row)
|
||
|
||
@item irr
|
||
interleaved rows (right eye has top row, left eye starts on next row)
|
||
|
||
@item icl
|
||
interleaved columns, left eye first
|
||
|
||
@item icr
|
||
interleaved columns, right eye first
|
||
|
||
Default value is @samp{sbsl}.
|
||
@end table
|
||
|
||
@item out
|
||
Set stereoscopic image format of output.
|
||
|
||
@table @samp
|
||
@item sbsl
|
||
side by side parallel (left eye left, right eye right)
|
||
|
||
@item sbsr
|
||
side by side crosseye (right eye left, left eye right)
|
||
|
||
@item sbs2l
|
||
side by side parallel with half width resolution
|
||
(left eye left, right eye right)
|
||
|
||
@item sbs2r
|
||
side by side crosseye with half width resolution
|
||
(right eye left, left eye right)
|
||
|
||
@item abl
|
||
above-below (left eye above, right eye below)
|
||
|
||
@item abr
|
||
above-below (right eye above, left eye below)
|
||
|
||
@item ab2l
|
||
above-below with half height resolution
|
||
(left eye above, right eye below)
|
||
|
||
@item ab2r
|
||
above-below with half height resolution
|
||
(right eye above, left eye below)
|
||
|
||
@item al
|
||
alternating frames (left eye first, right eye second)
|
||
|
||
@item ar
|
||
alternating frames (right eye first, left eye second)
|
||
|
||
@item irl
|
||
interleaved rows (left eye has top row, right eye starts on next row)
|
||
|
||
@item irr
|
||
interleaved rows (right eye has top row, left eye starts on next row)
|
||
|
||
@item arbg
|
||
anaglyph red/blue gray
|
||
(red filter on left eye, blue filter on right eye)
|
||
|
||
@item argg
|
||
anaglyph red/green gray
|
||
(red filter on left eye, green filter on right eye)
|
||
|
||
@item arcg
|
||
anaglyph red/cyan gray
|
||
(red filter on left eye, cyan filter on right eye)
|
||
|
||
@item arch
|
||
anaglyph red/cyan half colored
|
||
(red filter on left eye, cyan filter on right eye)
|
||
|
||
@item arcc
|
||
anaglyph red/cyan color
|
||
(red filter on left eye, cyan filter on right eye)
|
||
|
||
@item arcd
|
||
anaglyph red/cyan color optimized with the least squares projection of dubois
|
||
(red filter on left eye, cyan filter on right eye)
|
||
|
||
@item agmg
|
||
anaglyph green/magenta gray
|
||
(green filter on left eye, magenta filter on right eye)
|
||
|
||
@item agmh
|
||
anaglyph green/magenta half colored
|
||
(green filter on left eye, magenta filter on right eye)
|
||
|
||
@item agmc
|
||
anaglyph green/magenta colored
|
||
(green filter on left eye, magenta filter on right eye)
|
||
|
||
@item agmd
|
||
anaglyph green/magenta color optimized with the least squares projection of dubois
|
||
(green filter on left eye, magenta filter on right eye)
|
||
|
||
@item aybg
|
||
anaglyph yellow/blue gray
|
||
(yellow filter on left eye, blue filter on right eye)
|
||
|
||
@item aybh
|
||
anaglyph yellow/blue half colored
|
||
(yellow filter on left eye, blue filter on right eye)
|
||
|
||
@item aybc
|
||
anaglyph yellow/blue colored
|
||
(yellow filter on left eye, blue filter on right eye)
|
||
|
||
@item aybd
|
||
anaglyph yellow/blue color optimized with the least squares projection of dubois
|
||
(yellow filter on left eye, blue filter on right eye)
|
||
|
||
@item ml
|
||
mono output (left eye only)
|
||
|
||
@item mr
|
||
mono output (right eye only)
|
||
|
||
@item chl
|
||
checkerboard, left eye first
|
||
|
||
@item chr
|
||
checkerboard, right eye first
|
||
|
||
@item icl
|
||
interleaved columns, left eye first
|
||
|
||
@item icr
|
||
interleaved columns, right eye first
|
||
|
||
@item hdmi
|
||
HDMI frame pack
|
||
@end table
|
||
|
||
Default value is @samp{arcd}.
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Convert input video from side by side parallel to anaglyph yellow/blue dubois:
|
||
@example
|
||
stereo3d=sbsl:aybd
|
||
@end example
|
||
|
||
@item
|
||
Convert input video from above below (left eye above, right eye below) to side by side crosseye.
|
||
@example
|
||
stereo3d=abl:sbsr
|
||
@end example
|
||
@end itemize
|
||
|
||
@section streamselect, astreamselect
|
||
Select video or audio streams.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item inputs
|
||
Set number of inputs. Default is 2.
|
||
|
||
@item map
|
||
Set input indexes to remap to outputs.
|
||
@end table
|
||
|
||
@subsection Commands
|
||
|
||
The @code{streamselect} and @code{astreamselect} filter supports the following
|
||
commands:
|
||
|
||
@table @option
|
||
@item map
|
||
Set input indexes to remap to outputs.
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Select first 5 seconds 1st stream and rest of time 2nd stream:
|
||
@example
|
||
sendcmd='5.0 streamselect map 1',streamselect=inputs=2:map=0
|
||
@end example
|
||
|
||
@item
|
||
Same as above, but for audio:
|
||
@example
|
||
asendcmd='5.0 astreamselect map 1',astreamselect=inputs=2:map=0
|
||
@end example
|
||
@end itemize
|
||
|
||
@section sobel
|
||
Apply sobel operator to input video stream.
|
||
|
||
The filter accepts the following option:
|
||
|
||
@table @option
|
||
@item planes
|
||
Set which planes will be processed, unprocessed planes will be copied.
|
||
By default value 0xf, all planes will be processed.
|
||
|
||
@item scale
|
||
Set value which will be multiplied with filtered result.
|
||
|
||
@item delta
|
||
Set value which will be added to filtered result.
|
||
@end table
|
||
|
||
@anchor{spp}
|
||
@section spp
|
||
|
||
Apply a simple postprocessing filter that compresses and decompresses the image
|
||
at several (or - in the case of @option{quality} level @code{6} - all) shifts
|
||
and average the results.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item quality
|
||
Set quality. This option defines the number of levels for averaging. It accepts
|
||
an integer in the range 0-6. If set to @code{0}, the filter will have no
|
||
effect. A value of @code{6} means the higher quality. For each increment of
|
||
that value the speed drops by a factor of approximately 2. Default value is
|
||
@code{3}.
|
||
|
||
@item qp
|
||
Force a constant quantization parameter. If not set, the filter will use the QP
|
||
from the video stream (if available).
|
||
|
||
@item mode
|
||
Set thresholding mode. Available modes are:
|
||
|
||
@table @samp
|
||
@item hard
|
||
Set hard thresholding (default).
|
||
@item soft
|
||
Set soft thresholding (better de-ringing effect, but likely blurrier).
|
||
@end table
|
||
|
||
@item use_bframe_qp
|
||
Enable the use of the QP from the B-Frames if set to @code{1}. Using this
|
||
option may cause flicker since the B-Frames have often larger QP. Default is
|
||
@code{0} (not enabled).
|
||
@end table
|
||
|
||
@anchor{subtitles}
|
||
@section subtitles
|
||
|
||
Draw subtitles on top of input video using the libass library.
|
||
|
||
To enable compilation of this filter you need to configure FFmpeg with
|
||
@code{--enable-libass}. This filter also requires a build with libavcodec and
|
||
libavformat to convert the passed subtitles file to ASS (Advanced Substation
|
||
Alpha) subtitles format.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item filename, f
|
||
Set the filename of the subtitle file to read. It must be specified.
|
||
|
||
@item original_size
|
||
Specify the size of the original video, the video for which the ASS file
|
||
was composed. For the syntax of this option, check the
|
||
@ref{video size syntax,,"Video size" section in the ffmpeg-utils manual,ffmpeg-utils}.
|
||
Due to a misdesign in ASS aspect ratio arithmetic, this is necessary to
|
||
correctly scale the fonts if the aspect ratio has been changed.
|
||
|
||
@item fontsdir
|
||
Set a directory path containing fonts that can be used by the filter.
|
||
These fonts will be used in addition to whatever the font provider uses.
|
||
|
||
@item charenc
|
||
Set subtitles input character encoding. @code{subtitles} filter only. Only
|
||
useful if not UTF-8.
|
||
|
||
@item stream_index, si
|
||
Set subtitles stream index. @code{subtitles} filter only.
|
||
|
||
@item force_style
|
||
Override default style or script info parameters of the subtitles. It accepts a
|
||
string containing ASS style format @code{KEY=VALUE} couples separated by ",".
|
||
@end table
|
||
|
||
If the first key is not specified, it is assumed that the first value
|
||
specifies the @option{filename}.
|
||
|
||
For example, to render the file @file{sub.srt} on top of the input
|
||
video, use the command:
|
||
@example
|
||
subtitles=sub.srt
|
||
@end example
|
||
|
||
which is equivalent to:
|
||
@example
|
||
subtitles=filename=sub.srt
|
||
@end example
|
||
|
||
To render the default subtitles stream from file @file{video.mkv}, use:
|
||
@example
|
||
subtitles=video.mkv
|
||
@end example
|
||
|
||
To render the second subtitles stream from that file, use:
|
||
@example
|
||
subtitles=video.mkv:si=1
|
||
@end example
|
||
|
||
To make the subtitles stream from @file{sub.srt} appear in transparent green
|
||
@code{DejaVu Serif}, use:
|
||
@example
|
||
subtitles=sub.srt:force_style='FontName=DejaVu Serif,PrimaryColour=&HAA00FF00'
|
||
@end example
|
||
|
||
@section super2xsai
|
||
|
||
Scale the input by 2x and smooth using the Super2xSaI (Scale and
|
||
Interpolate) pixel art scaling algorithm.
|
||
|
||
Useful for enlarging pixel art images without reducing sharpness.
|
||
|
||
@section swaprect
|
||
|
||
Swap two rectangular objects in video.
|
||
|
||
This filter accepts the following options:
|
||
|
||
@table @option
|
||
@item w
|
||
Set object width.
|
||
|
||
@item h
|
||
Set object height.
|
||
|
||
@item x1
|
||
Set 1st rect x coordinate.
|
||
|
||
@item y1
|
||
Set 1st rect y coordinate.
|
||
|
||
@item x2
|
||
Set 2nd rect x coordinate.
|
||
|
||
@item y2
|
||
Set 2nd rect y coordinate.
|
||
|
||
All expressions are evaluated once for each frame.
|
||
@end table
|
||
|
||
The all options are expressions containing the following constants:
|
||
|
||
@table @option
|
||
@item w
|
||
@item h
|
||
The input width and height.
|
||
|
||
@item a
|
||
same as @var{w} / @var{h}
|
||
|
||
@item sar
|
||
input sample aspect ratio
|
||
|
||
@item dar
|
||
input display aspect ratio, it is the same as (@var{w} / @var{h}) * @var{sar}
|
||
|
||
@item n
|
||
The number of the input frame, starting from 0.
|
||
|
||
@item t
|
||
The timestamp expressed in seconds. It's NAN if the input timestamp is unknown.
|
||
|
||
@item pos
|
||
the position in the file of the input frame, NAN if unknown
|
||
@end table
|
||
|
||
@section swapuv
|
||
Swap U & V plane.
|
||
|
||
@section telecine
|
||
|
||
Apply telecine process to the video.
|
||
|
||
This filter accepts the following options:
|
||
|
||
@table @option
|
||
@item first_field
|
||
@table @samp
|
||
@item top, t
|
||
top field first
|
||
@item bottom, b
|
||
bottom field first
|
||
The default value is @code{top}.
|
||
@end table
|
||
|
||
@item pattern
|
||
A string of numbers representing the pulldown pattern you wish to apply.
|
||
The default value is @code{23}.
|
||
@end table
|
||
|
||
@example
|
||
Some typical patterns:
|
||
|
||
NTSC output (30i):
|
||
27.5p: 32222
|
||
24p: 23 (classic)
|
||
24p: 2332 (preferred)
|
||
20p: 33
|
||
18p: 334
|
||
16p: 3444
|
||
|
||
PAL output (25i):
|
||
27.5p: 12222
|
||
24p: 222222222223 ("Euro pulldown")
|
||
16.67p: 33
|
||
16p: 33333334
|
||
@end example
|
||
|
||
@section threshold
|
||
|
||
Apply threshold effect to video stream.
|
||
|
||
This filter needs four video streams to perform thresholding.
|
||
First stream is stream we are filtering.
|
||
Second stream is holding threshold values, third stream is holding min values,
|
||
and last, fourth stream is holding max values.
|
||
|
||
The filter accepts the following option:
|
||
|
||
@table @option
|
||
@item planes
|
||
Set which planes will be processed, unprocessed planes will be copied.
|
||
By default value 0xf, all planes will be processed.
|
||
@end table
|
||
|
||
For example if first stream pixel's component value is less then threshold value
|
||
of pixel component from 2nd threshold stream, third stream value will picked,
|
||
otherwise fourth stream pixel component value will be picked.
|
||
|
||
Using color source filter one can perform various types of thresholding:
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Binary threshold, using gray color as threshold:
|
||
@example
|
||
ffmpeg -i 320x240.avi -f lavfi -i color=gray -f lavfi -i color=black -f lavfi -i color=white -lavfi threshold output.avi
|
||
@end example
|
||
|
||
@item
|
||
Inverted binary threshold, using gray color as threshold:
|
||
@example
|
||
ffmpeg -i 320x240.avi -f lavfi -i color=gray -f lavfi -i color=white -f lavfi -i color=black -lavfi threshold output.avi
|
||
@end example
|
||
|
||
@item
|
||
Truncate binary threshold, using gray color as threshold:
|
||
@example
|
||
ffmpeg -i 320x240.avi -f lavfi -i color=gray -i 320x240.avi -f lavfi -i color=gray -lavfi threshold output.avi
|
||
@end example
|
||
|
||
@item
|
||
Threshold to zero, using gray color as threshold:
|
||
@example
|
||
ffmpeg -i 320x240.avi -f lavfi -i color=gray -f lavfi -i color=white -i 320x240.avi -lavfi threshold output.avi
|
||
@end example
|
||
|
||
@item
|
||
Inverted threshold to zero, using gray color as threshold:
|
||
@example
|
||
ffmpeg -i 320x240.avi -f lavfi -i color=gray -i 320x240.avi -f lavfi -i color=white -lavfi threshold output.avi
|
||
@end example
|
||
@end itemize
|
||
|
||
@section thumbnail
|
||
Select the most representative frame in a given sequence of consecutive frames.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item n
|
||
Set the frames batch size to analyze; in a set of @var{n} frames, the filter
|
||
will pick one of them, and then handle the next batch of @var{n} frames until
|
||
the end. Default is @code{100}.
|
||
@end table
|
||
|
||
Since the filter keeps track of the whole frames sequence, a bigger @var{n}
|
||
value will result in a higher memory usage, so a high value is not recommended.
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Extract one picture each 50 frames:
|
||
@example
|
||
thumbnail=50
|
||
@end example
|
||
|
||
@item
|
||
Complete example of a thumbnail creation with @command{ffmpeg}:
|
||
@example
|
||
ffmpeg -i in.avi -vf thumbnail,scale=300:200 -frames:v 1 out.png
|
||
@end example
|
||
@end itemize
|
||
|
||
@section tile
|
||
|
||
Tile several successive frames together.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
|
||
@item layout
|
||
Set the grid size (i.e. the number of lines and columns). For the syntax of
|
||
this option, check the
|
||
@ref{video size syntax,,"Video size" section in the ffmpeg-utils manual,ffmpeg-utils}.
|
||
|
||
@item nb_frames
|
||
Set the maximum number of frames to render in the given area. It must be less
|
||
than or equal to @var{w}x@var{h}. The default value is @code{0}, meaning all
|
||
the area will be used.
|
||
|
||
@item margin
|
||
Set the outer border margin in pixels.
|
||
|
||
@item padding
|
||
Set the inner border thickness (i.e. the number of pixels between frames). For
|
||
more advanced padding options (such as having different values for the edges),
|
||
refer to the pad video filter.
|
||
|
||
@item color
|
||
Specify the color of the unused area. For the syntax of this option, check the
|
||
"Color" section in the ffmpeg-utils manual. The default value of @var{color}
|
||
is "black".
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Produce 8x8 PNG tiles of all keyframes (@option{-skip_frame nokey}) in a movie:
|
||
@example
|
||
ffmpeg -skip_frame nokey -i file.avi -vf 'scale=128:72,tile=8x8' -an -vsync 0 keyframes%03d.png
|
||
@end example
|
||
The @option{-vsync 0} is necessary to prevent @command{ffmpeg} from
|
||
duplicating each output frame to accommodate the originally detected frame
|
||
rate.
|
||
|
||
@item
|
||
Display @code{5} pictures in an area of @code{3x2} frames,
|
||
with @code{7} pixels between them, and @code{2} pixels of initial margin, using
|
||
mixed flat and named options:
|
||
@example
|
||
tile=3x2:nb_frames=5:padding=7:margin=2
|
||
@end example
|
||
@end itemize
|
||
|
||
@section tinterlace
|
||
|
||
Perform various types of temporal field interlacing.
|
||
|
||
Frames are counted starting from 1, so the first input frame is
|
||
considered odd.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
|
||
@item mode
|
||
Specify the mode of the interlacing. This option can also be specified
|
||
as a value alone. See below for a list of values for this option.
|
||
|
||
Available values are:
|
||
|
||
@table @samp
|
||
@item merge, 0
|
||
Move odd frames into the upper field, even into the lower field,
|
||
generating a double height frame at half frame rate.
|
||
@example
|
||
------> time
|
||
Input:
|
||
Frame 1 Frame 2 Frame 3 Frame 4
|
||
|
||
11111 22222 33333 44444
|
||
11111 22222 33333 44444
|
||
11111 22222 33333 44444
|
||
11111 22222 33333 44444
|
||
|
||
Output:
|
||
11111 33333
|
||
22222 44444
|
||
11111 33333
|
||
22222 44444
|
||
11111 33333
|
||
22222 44444
|
||
11111 33333
|
||
22222 44444
|
||
@end example
|
||
|
||
@item drop_even, 1
|
||
Only output odd frames, even frames are dropped, generating a frame with
|
||
unchanged height at half frame rate.
|
||
|
||
@example
|
||
------> time
|
||
Input:
|
||
Frame 1 Frame 2 Frame 3 Frame 4
|
||
|
||
11111 22222 33333 44444
|
||
11111 22222 33333 44444
|
||
11111 22222 33333 44444
|
||
11111 22222 33333 44444
|
||
|
||
Output:
|
||
11111 33333
|
||
11111 33333
|
||
11111 33333
|
||
11111 33333
|
||
@end example
|
||
|
||
@item drop_odd, 2
|
||
Only output even frames, odd frames are dropped, generating a frame with
|
||
unchanged height at half frame rate.
|
||
|
||
@example
|
||
------> time
|
||
Input:
|
||
Frame 1 Frame 2 Frame 3 Frame 4
|
||
|
||
11111 22222 33333 44444
|
||
11111 22222 33333 44444
|
||
11111 22222 33333 44444
|
||
11111 22222 33333 44444
|
||
|
||
Output:
|
||
22222 44444
|
||
22222 44444
|
||
22222 44444
|
||
22222 44444
|
||
@end example
|
||
|
||
@item pad, 3
|
||
Expand each frame to full height, but pad alternate lines with black,
|
||
generating a frame with double height at the same input frame rate.
|
||
|
||
@example
|
||
------> time
|
||
Input:
|
||
Frame 1 Frame 2 Frame 3 Frame 4
|
||
|
||
11111 22222 33333 44444
|
||
11111 22222 33333 44444
|
||
11111 22222 33333 44444
|
||
11111 22222 33333 44444
|
||
|
||
Output:
|
||
11111 ..... 33333 .....
|
||
..... 22222 ..... 44444
|
||
11111 ..... 33333 .....
|
||
..... 22222 ..... 44444
|
||
11111 ..... 33333 .....
|
||
..... 22222 ..... 44444
|
||
11111 ..... 33333 .....
|
||
..... 22222 ..... 44444
|
||
@end example
|
||
|
||
|
||
@item interleave_top, 4
|
||
Interleave the upper field from odd frames with the lower field from
|
||
even frames, generating a frame with unchanged height at half frame rate.
|
||
|
||
@example
|
||
------> time
|
||
Input:
|
||
Frame 1 Frame 2 Frame 3 Frame 4
|
||
|
||
11111<- 22222 33333<- 44444
|
||
11111 22222<- 33333 44444<-
|
||
11111<- 22222 33333<- 44444
|
||
11111 22222<- 33333 44444<-
|
||
|
||
Output:
|
||
11111 33333
|
||
22222 44444
|
||
11111 33333
|
||
22222 44444
|
||
@end example
|
||
|
||
|
||
@item interleave_bottom, 5
|
||
Interleave the lower field from odd frames with the upper field from
|
||
even frames, generating a frame with unchanged height at half frame rate.
|
||
|
||
@example
|
||
------> time
|
||
Input:
|
||
Frame 1 Frame 2 Frame 3 Frame 4
|
||
|
||
11111 22222<- 33333 44444<-
|
||
11111<- 22222 33333<- 44444
|
||
11111 22222<- 33333 44444<-
|
||
11111<- 22222 33333<- 44444
|
||
|
||
Output:
|
||
22222 44444
|
||
11111 33333
|
||
22222 44444
|
||
11111 33333
|
||
@end example
|
||
|
||
|
||
@item interlacex2, 6
|
||
Double frame rate with unchanged height. Frames are inserted each
|
||
containing the second temporal field from the previous input frame and
|
||
the first temporal field from the next input frame. This mode relies on
|
||
the top_field_first flag. Useful for interlaced video displays with no
|
||
field synchronisation.
|
||
|
||
@example
|
||
------> time
|
||
Input:
|
||
Frame 1 Frame 2 Frame 3 Frame 4
|
||
|
||
11111 22222 33333 44444
|
||
11111 22222 33333 44444
|
||
11111 22222 33333 44444
|
||
11111 22222 33333 44444
|
||
|
||
Output:
|
||
11111 22222 22222 33333 33333 44444 44444
|
||
11111 11111 22222 22222 33333 33333 44444
|
||
11111 22222 22222 33333 33333 44444 44444
|
||
11111 11111 22222 22222 33333 33333 44444
|
||
@end example
|
||
|
||
|
||
@item mergex2, 7
|
||
Move odd frames into the upper field, even into the lower field,
|
||
generating a double height frame at same frame rate.
|
||
|
||
@example
|
||
------> time
|
||
Input:
|
||
Frame 1 Frame 2 Frame 3 Frame 4
|
||
|
||
11111 22222 33333 44444
|
||
11111 22222 33333 44444
|
||
11111 22222 33333 44444
|
||
11111 22222 33333 44444
|
||
|
||
Output:
|
||
11111 33333 33333 55555
|
||
22222 22222 44444 44444
|
||
11111 33333 33333 55555
|
||
22222 22222 44444 44444
|
||
11111 33333 33333 55555
|
||
22222 22222 44444 44444
|
||
11111 33333 33333 55555
|
||
22222 22222 44444 44444
|
||
@end example
|
||
|
||
@end table
|
||
|
||
Numeric values are deprecated but are accepted for backward
|
||
compatibility reasons.
|
||
|
||
Default mode is @code{merge}.
|
||
|
||
@item flags
|
||
Specify flags influencing the filter process.
|
||
|
||
Available value for @var{flags} is:
|
||
|
||
@table @option
|
||
@item low_pass_filter, vlfp
|
||
Enable linear vertical low-pass filtering in the filter.
|
||
Vertical low-pass filtering is required when creating an interlaced
|
||
destination from a progressive source which contains high-frequency
|
||
vertical detail. Filtering will reduce interlace 'twitter' and Moire
|
||
patterning.
|
||
|
||
@item complex_filter, cvlfp
|
||
Enable complex vertical low-pass filtering.
|
||
This will slightly less reduce interlace 'twitter' and Moire
|
||
patterning but better retain detail and subjective sharpness impression.
|
||
|
||
@end table
|
||
|
||
Vertical low-pass filtering can only be enabled for @option{mode}
|
||
@var{interleave_top} and @var{interleave_bottom}.
|
||
|
||
@end table
|
||
|
||
@section transpose
|
||
|
||
Transpose rows with columns in the input video and optionally flip it.
|
||
|
||
It accepts the following parameters:
|
||
|
||
@table @option
|
||
|
||
@item dir
|
||
Specify the transposition direction.
|
||
|
||
Can assume the following values:
|
||
@table @samp
|
||
@item 0, 4, cclock_flip
|
||
Rotate by 90 degrees counterclockwise and vertically flip (default), that is:
|
||
@example
|
||
L.R L.l
|
||
. . -> . .
|
||
l.r R.r
|
||
@end example
|
||
|
||
@item 1, 5, clock
|
||
Rotate by 90 degrees clockwise, that is:
|
||
@example
|
||
L.R l.L
|
||
. . -> . .
|
||
l.r r.R
|
||
@end example
|
||
|
||
@item 2, 6, cclock
|
||
Rotate by 90 degrees counterclockwise, that is:
|
||
@example
|
||
L.R R.r
|
||
. . -> . .
|
||
l.r L.l
|
||
@end example
|
||
|
||
@item 3, 7, clock_flip
|
||
Rotate by 90 degrees clockwise and vertically flip, that is:
|
||
@example
|
||
L.R r.R
|
||
. . -> . .
|
||
l.r l.L
|
||
@end example
|
||
@end table
|
||
|
||
For values between 4-7, the transposition is only done if the input
|
||
video geometry is portrait and not landscape. These values are
|
||
deprecated, the @code{passthrough} option should be used instead.
|
||
|
||
Numerical values are deprecated, and should be dropped in favor of
|
||
symbolic constants.
|
||
|
||
@item passthrough
|
||
Do not apply the transposition if the input geometry matches the one
|
||
specified by the specified value. It accepts the following values:
|
||
@table @samp
|
||
@item none
|
||
Always apply transposition.
|
||
@item portrait
|
||
Preserve portrait geometry (when @var{height} >= @var{width}).
|
||
@item landscape
|
||
Preserve landscape geometry (when @var{width} >= @var{height}).
|
||
@end table
|
||
|
||
Default value is @code{none}.
|
||
@end table
|
||
|
||
For example to rotate by 90 degrees clockwise and preserve portrait
|
||
layout:
|
||
@example
|
||
transpose=dir=1:passthrough=portrait
|
||
@end example
|
||
|
||
The command above can also be specified as:
|
||
@example
|
||
transpose=1:portrait
|
||
@end example
|
||
|
||
@section trim
|
||
Trim the input so that the output contains one continuous subpart of the input.
|
||
|
||
It accepts the following parameters:
|
||
@table @option
|
||
@item start
|
||
Specify the time of the start of the kept section, i.e. the frame with the
|
||
timestamp @var{start} will be the first frame in the output.
|
||
|
||
@item end
|
||
Specify the time of the first frame that will be dropped, i.e. the frame
|
||
immediately preceding the one with the timestamp @var{end} will be the last
|
||
frame in the output.
|
||
|
||
@item start_pts
|
||
This is the same as @var{start}, except this option sets the start timestamp
|
||
in timebase units instead of seconds.
|
||
|
||
@item end_pts
|
||
This is the same as @var{end}, except this option sets the end timestamp
|
||
in timebase units instead of seconds.
|
||
|
||
@item duration
|
||
The maximum duration of the output in seconds.
|
||
|
||
@item start_frame
|
||
The number of the first frame that should be passed to the output.
|
||
|
||
@item end_frame
|
||
The number of the first frame that should be dropped.
|
||
@end table
|
||
|
||
@option{start}, @option{end}, and @option{duration} are expressed as time
|
||
duration specifications; see
|
||
@ref{time duration syntax,,the Time duration section in the ffmpeg-utils(1) manual,ffmpeg-utils}
|
||
for the accepted syntax.
|
||
|
||
Note that the first two sets of the start/end options and the @option{duration}
|
||
option look at the frame timestamp, while the _frame variants simply count the
|
||
frames that pass through the filter. Also note that this filter does not modify
|
||
the timestamps. If you wish for the output timestamps to start at zero, insert a
|
||
setpts filter after the trim filter.
|
||
|
||
If multiple start or end options are set, this filter tries to be greedy and
|
||
keep all the frames that match at least one of the specified constraints. To keep
|
||
only the part that matches all the constraints at once, chain multiple trim
|
||
filters.
|
||
|
||
The defaults are such that all the input is kept. So it is possible to set e.g.
|
||
just the end values to keep everything before the specified time.
|
||
|
||
Examples:
|
||
@itemize
|
||
@item
|
||
Drop everything except the second minute of input:
|
||
@example
|
||
ffmpeg -i INPUT -vf trim=60:120
|
||
@end example
|
||
|
||
@item
|
||
Keep only the first second:
|
||
@example
|
||
ffmpeg -i INPUT -vf trim=duration=1
|
||
@end example
|
||
|
||
@end itemize
|
||
|
||
@section unpremultiply
|
||
Apply alpha unpremultiply effect to input video stream using first plane
|
||
of second stream as alpha.
|
||
|
||
Both streams must have same dimensions and same pixel format.
|
||
|
||
The filter accepts the following option:
|
||
|
||
@table @option
|
||
@item planes
|
||
Set which planes will be processed, unprocessed planes will be copied.
|
||
By default value 0xf, all planes will be processed.
|
||
|
||
If the format has 1 or 2 components, then luma is bit 0.
|
||
If the format has 3 or 4 components:
|
||
for RGB formats bit 0 is green, bit 1 is blue and bit 2 is red;
|
||
for YUV formats bit 0 is luma, bit 1 is chroma-U and bit 2 is chroma-V.
|
||
If present, the alpha channel is always the last bit.
|
||
@end table
|
||
|
||
@anchor{unsharp}
|
||
@section unsharp
|
||
|
||
Sharpen or blur the input video.
|
||
|
||
It accepts the following parameters:
|
||
|
||
@table @option
|
||
@item luma_msize_x, lx
|
||
Set the luma matrix horizontal size. It must be an odd integer between
|
||
3 and 23. The default value is 5.
|
||
|
||
@item luma_msize_y, ly
|
||
Set the luma matrix vertical size. It must be an odd integer between 3
|
||
and 23. The default value is 5.
|
||
|
||
@item luma_amount, la
|
||
Set the luma effect strength. It must be a floating point number, reasonable
|
||
values lay between -1.5 and 1.5.
|
||
|
||
Negative values will blur the input video, while positive values will
|
||
sharpen it, a value of zero will disable the effect.
|
||
|
||
Default value is 1.0.
|
||
|
||
@item chroma_msize_x, cx
|
||
Set the chroma matrix horizontal size. It must be an odd integer
|
||
between 3 and 23. The default value is 5.
|
||
|
||
@item chroma_msize_y, cy
|
||
Set the chroma matrix vertical size. It must be an odd integer
|
||
between 3 and 23. The default value is 5.
|
||
|
||
@item chroma_amount, ca
|
||
Set the chroma effect strength. It must be a floating point number, reasonable
|
||
values lay between -1.5 and 1.5.
|
||
|
||
Negative values will blur the input video, while positive values will
|
||
sharpen it, a value of zero will disable the effect.
|
||
|
||
Default value is 0.0.
|
||
|
||
@item opencl
|
||
If set to 1, specify using OpenCL capabilities, only available if
|
||
FFmpeg was configured with @code{--enable-opencl}. Default value is 0.
|
||
|
||
@end table
|
||
|
||
All parameters are optional and default to the equivalent of the
|
||
string '5:5:1.0:5:5:0.0'.
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Apply strong luma sharpen effect:
|
||
@example
|
||
unsharp=luma_msize_x=7:luma_msize_y=7:luma_amount=2.5
|
||
@end example
|
||
|
||
@item
|
||
Apply a strong blur of both luma and chroma parameters:
|
||
@example
|
||
unsharp=7:7:-2:7:7:-2
|
||
@end example
|
||
@end itemize
|
||
|
||
@section uspp
|
||
|
||
Apply ultra slow/simple postprocessing filter that compresses and decompresses
|
||
the image at several (or - in the case of @option{quality} level @code{8} - all)
|
||
shifts and average the results.
|
||
|
||
The way this differs from the behavior of spp is that uspp actually encodes &
|
||
decodes each case with libavcodec Snow, whereas spp uses a simplified intra only 8x8
|
||
DCT similar to MJPEG.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item quality
|
||
Set quality. This option defines the number of levels for averaging. It accepts
|
||
an integer in the range 0-8. If set to @code{0}, the filter will have no
|
||
effect. A value of @code{8} means the higher quality. For each increment of
|
||
that value the speed drops by a factor of approximately 2. Default value is
|
||
@code{3}.
|
||
|
||
@item qp
|
||
Force a constant quantization parameter. If not set, the filter will use the QP
|
||
from the video stream (if available).
|
||
@end table
|
||
|
||
@section vaguedenoiser
|
||
|
||
Apply a wavelet based denoiser.
|
||
|
||
It transforms each frame from the video input into the wavelet domain,
|
||
using Cohen-Daubechies-Feauveau 9/7. Then it applies some filtering to
|
||
the obtained coefficients. It does an inverse wavelet transform after.
|
||
Due to wavelet properties, it should give a nice smoothed result, and
|
||
reduced noise, without blurring picture features.
|
||
|
||
This filter accepts the following options:
|
||
|
||
@table @option
|
||
@item threshold
|
||
The filtering strength. The higher, the more filtered the video will be.
|
||
Hard thresholding can use a higher threshold than soft thresholding
|
||
before the video looks overfiltered.
|
||
|
||
@item method
|
||
The filtering method the filter will use.
|
||
|
||
It accepts the following values:
|
||
@table @samp
|
||
@item hard
|
||
All values under the threshold will be zeroed.
|
||
|
||
@item soft
|
||
All values under the threshold will be zeroed. All values above will be
|
||
reduced by the threshold.
|
||
|
||
@item garrote
|
||
Scales or nullifies coefficients - intermediary between (more) soft and
|
||
(less) hard thresholding.
|
||
@end table
|
||
|
||
@item nsteps
|
||
Number of times, the wavelet will decompose the picture. Picture can't
|
||
be decomposed beyond a particular point (typically, 8 for a 640x480
|
||
frame - as 2^9 = 512 > 480)
|
||
|
||
@item percent
|
||
Partial of full denoising (limited coefficients shrinking), from 0 to 100.
|
||
|
||
@item planes
|
||
A list of the planes to process. By default all planes are processed.
|
||
@end table
|
||
|
||
@section vectorscope
|
||
|
||
Display 2 color component values in the two dimensional graph (which is called
|
||
a vectorscope).
|
||
|
||
This filter accepts the following options:
|
||
|
||
@table @option
|
||
@item mode, m
|
||
Set vectorscope mode.
|
||
|
||
It accepts the following values:
|
||
@table @samp
|
||
@item gray
|
||
Gray values are displayed on graph, higher brightness means more pixels have
|
||
same component color value on location in graph. This is the default mode.
|
||
|
||
@item color
|
||
Gray values are displayed on graph. Surrounding pixels values which are not
|
||
present in video frame are drawn in gradient of 2 color components which are
|
||
set by option @code{x} and @code{y}. The 3rd color component is static.
|
||
|
||
@item color2
|
||
Actual color components values present in video frame are displayed on graph.
|
||
|
||
@item color3
|
||
Similar as color2 but higher frequency of same values @code{x} and @code{y}
|
||
on graph increases value of another color component, which is luminance by
|
||
default values of @code{x} and @code{y}.
|
||
|
||
@item color4
|
||
Actual colors present in video frame are displayed on graph. If two different
|
||
colors map to same position on graph then color with higher value of component
|
||
not present in graph is picked.
|
||
|
||
@item color5
|
||
Gray values are displayed on graph. Similar to @code{color} but with 3rd color
|
||
component picked from radial gradient.
|
||
@end table
|
||
|
||
@item x
|
||
Set which color component will be represented on X-axis. Default is @code{1}.
|
||
|
||
@item y
|
||
Set which color component will be represented on Y-axis. Default is @code{2}.
|
||
|
||
@item intensity, i
|
||
Set intensity, used by modes: gray, color, color3 and color5 for increasing brightness
|
||
of color component which represents frequency of (X, Y) location in graph.
|
||
|
||
@item envelope, e
|
||
@table @samp
|
||
@item none
|
||
No envelope, this is default.
|
||
|
||
@item instant
|
||
Instant envelope, even darkest single pixel will be clearly highlighted.
|
||
|
||
@item peak
|
||
Hold maximum and minimum values presented in graph over time. This way you
|
||
can still spot out of range values without constantly looking at vectorscope.
|
||
|
||
@item peak+instant
|
||
Peak and instant envelope combined together.
|
||
@end table
|
||
|
||
@item graticule, g
|
||
Set what kind of graticule to draw.
|
||
@table @samp
|
||
@item none
|
||
@item green
|
||
@item color
|
||
@end table
|
||
|
||
@item opacity, o
|
||
Set graticule opacity.
|
||
|
||
@item flags, f
|
||
Set graticule flags.
|
||
|
||
@table @samp
|
||
@item white
|
||
Draw graticule for white point.
|
||
|
||
@item black
|
||
Draw graticule for black point.
|
||
|
||
@item name
|
||
Draw color points short names.
|
||
@end table
|
||
|
||
@item bgopacity, b
|
||
Set background opacity.
|
||
|
||
@item lthreshold, l
|
||
Set low threshold for color component not represented on X or Y axis.
|
||
Values lower than this value will be ignored. Default is 0.
|
||
Note this value is multiplied with actual max possible value one pixel component
|
||
can have. So for 8-bit input and low threshold value of 0.1 actual threshold
|
||
is 0.1 * 255 = 25.
|
||
|
||
@item hthreshold, h
|
||
Set high threshold for color component not represented on X or Y axis.
|
||
Values higher than this value will be ignored. Default is 1.
|
||
Note this value is multiplied with actual max possible value one pixel component
|
||
can have. So for 8-bit input and high threshold value of 0.9 actual threshold
|
||
is 0.9 * 255 = 230.
|
||
|
||
@item colorspace, c
|
||
Set what kind of colorspace to use when drawing graticule.
|
||
@table @samp
|
||
@item auto
|
||
@item 601
|
||
@item 709
|
||
@end table
|
||
Default is auto.
|
||
@end table
|
||
|
||
@anchor{vidstabdetect}
|
||
@section vidstabdetect
|
||
|
||
Analyze video stabilization/deshaking. Perform pass 1 of 2, see
|
||
@ref{vidstabtransform} for pass 2.
|
||
|
||
This filter generates a file with relative translation and rotation
|
||
transform information about subsequent frames, which is then used by
|
||
the @ref{vidstabtransform} filter.
|
||
|
||
To enable compilation of this filter you need to configure FFmpeg with
|
||
@code{--enable-libvidstab}.
|
||
|
||
This filter accepts the following options:
|
||
|
||
@table @option
|
||
@item result
|
||
Set the path to the file used to write the transforms information.
|
||
Default value is @file{transforms.trf}.
|
||
|
||
@item shakiness
|
||
Set how shaky the video is and how quick the camera is. It accepts an
|
||
integer in the range 1-10, a value of 1 means little shakiness, a
|
||
value of 10 means strong shakiness. Default value is 5.
|
||
|
||
@item accuracy
|
||
Set the accuracy of the detection process. It must be a value in the
|
||
range 1-15. A value of 1 means low accuracy, a value of 15 means high
|
||
accuracy. Default value is 15.
|
||
|
||
@item stepsize
|
||
Set stepsize of the search process. The region around minimum is
|
||
scanned with 1 pixel resolution. Default value is 6.
|
||
|
||
@item mincontrast
|
||
Set minimum contrast. Below this value a local measurement field is
|
||
discarded. Must be a floating point value in the range 0-1. Default
|
||
value is 0.3.
|
||
|
||
@item tripod
|
||
Set reference frame number for tripod mode.
|
||
|
||
If enabled, the motion of the frames is compared to a reference frame
|
||
in the filtered stream, identified by the specified number. The idea
|
||
is to compensate all movements in a more-or-less static scene and keep
|
||
the camera view absolutely still.
|
||
|
||
If set to 0, it is disabled. The frames are counted starting from 1.
|
||
|
||
@item show
|
||
Show fields and transforms in the resulting frames. It accepts an
|
||
integer in the range 0-2. Default value is 0, which disables any
|
||
visualization.
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Use default values:
|
||
@example
|
||
vidstabdetect
|
||
@end example
|
||
|
||
@item
|
||
Analyze strongly shaky movie and put the results in file
|
||
@file{mytransforms.trf}:
|
||
@example
|
||
vidstabdetect=shakiness=10:accuracy=15:result="mytransforms.trf"
|
||
@end example
|
||
|
||
@item
|
||
Visualize the result of internal transformations in the resulting
|
||
video:
|
||
@example
|
||
vidstabdetect=show=1
|
||
@end example
|
||
|
||
@item
|
||
Analyze a video with medium shakiness using @command{ffmpeg}:
|
||
@example
|
||
ffmpeg -i input -vf vidstabdetect=shakiness=5:show=1 dummy.avi
|
||
@end example
|
||
@end itemize
|
||
|
||
@anchor{vidstabtransform}
|
||
@section vidstabtransform
|
||
|
||
Video stabilization/deshaking: pass 2 of 2,
|
||
see @ref{vidstabdetect} for pass 1.
|
||
|
||
Read a file with transform information for each frame and
|
||
apply/compensate them. Together with the @ref{vidstabdetect}
|
||
filter this can be used to deshake videos. See also
|
||
@url{http://public.hronopik.de/vid.stab}. It is important to also use
|
||
the @ref{unsharp} filter, see below.
|
||
|
||
To enable compilation of this filter you need to configure FFmpeg with
|
||
@code{--enable-libvidstab}.
|
||
|
||
@subsection Options
|
||
|
||
@table @option
|
||
@item input
|
||
Set path to the file used to read the transforms. Default value is
|
||
@file{transforms.trf}.
|
||
|
||
@item smoothing
|
||
Set the number of frames (value*2 + 1) used for lowpass filtering the
|
||
camera movements. Default value is 10.
|
||
|
||
For example a number of 10 means that 21 frames are used (10 in the
|
||
past and 10 in the future) to smoothen the motion in the video. A
|
||
larger value leads to a smoother video, but limits the acceleration of
|
||
the camera (pan/tilt movements). 0 is a special case where a static
|
||
camera is simulated.
|
||
|
||
@item optalgo
|
||
Set the camera path optimization algorithm.
|
||
|
||
Accepted values are:
|
||
@table @samp
|
||
@item gauss
|
||
gaussian kernel low-pass filter on camera motion (default)
|
||
@item avg
|
||
averaging on transformations
|
||
@end table
|
||
|
||
@item maxshift
|
||
Set maximal number of pixels to translate frames. Default value is -1,
|
||
meaning no limit.
|
||
|
||
@item maxangle
|
||
Set maximal angle in radians (degree*PI/180) to rotate frames. Default
|
||
value is -1, meaning no limit.
|
||
|
||
@item crop
|
||
Specify how to deal with borders that may be visible due to movement
|
||
compensation.
|
||
|
||
Available values are:
|
||
@table @samp
|
||
@item keep
|
||
keep image information from previous frame (default)
|
||
@item black
|
||
fill the border black
|
||
@end table
|
||
|
||
@item invert
|
||
Invert transforms if set to 1. Default value is 0.
|
||
|
||
@item relative
|
||
Consider transforms as relative to previous frame if set to 1,
|
||
absolute if set to 0. Default value is 0.
|
||
|
||
@item zoom
|
||
Set percentage to zoom. A positive value will result in a zoom-in
|
||
effect, a negative value in a zoom-out effect. Default value is 0 (no
|
||
zoom).
|
||
|
||
@item optzoom
|
||
Set optimal zooming to avoid borders.
|
||
|
||
Accepted values are:
|
||
@table @samp
|
||
@item 0
|
||
disabled
|
||
@item 1
|
||
optimal static zoom value is determined (only very strong movements
|
||
will lead to visible borders) (default)
|
||
@item 2
|
||
optimal adaptive zoom value is determined (no borders will be
|
||
visible), see @option{zoomspeed}
|
||
@end table
|
||
|
||
Note that the value given at zoom is added to the one calculated here.
|
||
|
||
@item zoomspeed
|
||
Set percent to zoom maximally each frame (enabled when
|
||
@option{optzoom} is set to 2). Range is from 0 to 5, default value is
|
||
0.25.
|
||
|
||
@item interpol
|
||
Specify type of interpolation.
|
||
|
||
Available values are:
|
||
@table @samp
|
||
@item no
|
||
no interpolation
|
||
@item linear
|
||
linear only horizontal
|
||
@item bilinear
|
||
linear in both directions (default)
|
||
@item bicubic
|
||
cubic in both directions (slow)
|
||
@end table
|
||
|
||
@item tripod
|
||
Enable virtual tripod mode if set to 1, which is equivalent to
|
||
@code{relative=0:smoothing=0}. Default value is 0.
|
||
|
||
Use also @code{tripod} option of @ref{vidstabdetect}.
|
||
|
||
@item debug
|
||
Increase log verbosity if set to 1. Also the detected global motions
|
||
are written to the temporary file @file{global_motions.trf}. Default
|
||
value is 0.
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Use @command{ffmpeg} for a typical stabilization with default values:
|
||
@example
|
||
ffmpeg -i inp.mpeg -vf vidstabtransform,unsharp=5:5:0.8:3:3:0.4 inp_stabilized.mpeg
|
||
@end example
|
||
|
||
Note the use of the @ref{unsharp} filter which is always recommended.
|
||
|
||
@item
|
||
Zoom in a bit more and load transform data from a given file:
|
||
@example
|
||
vidstabtransform=zoom=5:input="mytransforms.trf"
|
||
@end example
|
||
|
||
@item
|
||
Smoothen the video even more:
|
||
@example
|
||
vidstabtransform=smoothing=30
|
||
@end example
|
||
@end itemize
|
||
|
||
@section vflip
|
||
|
||
Flip the input video vertically.
|
||
|
||
For example, to vertically flip a video with @command{ffmpeg}:
|
||
@example
|
||
ffmpeg -i in.avi -vf "vflip" out.avi
|
||
@end example
|
||
|
||
@anchor{vignette}
|
||
@section vignette
|
||
|
||
Make or reverse a natural vignetting effect.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item angle, a
|
||
Set lens angle expression as a number of radians.
|
||
|
||
The value is clipped in the @code{[0,PI/2]} range.
|
||
|
||
Default value: @code{"PI/5"}
|
||
|
||
@item x0
|
||
@item y0
|
||
Set center coordinates expressions. Respectively @code{"w/2"} and @code{"h/2"}
|
||
by default.
|
||
|
||
@item mode
|
||
Set forward/backward mode.
|
||
|
||
Available modes are:
|
||
@table @samp
|
||
@item forward
|
||
The larger the distance from the central point, the darker the image becomes.
|
||
|
||
@item backward
|
||
The larger the distance from the central point, the brighter the image becomes.
|
||
This can be used to reverse a vignette effect, though there is no automatic
|
||
detection to extract the lens @option{angle} and other settings (yet). It can
|
||
also be used to create a burning effect.
|
||
@end table
|
||
|
||
Default value is @samp{forward}.
|
||
|
||
@item eval
|
||
Set evaluation mode for the expressions (@option{angle}, @option{x0}, @option{y0}).
|
||
|
||
It accepts the following values:
|
||
@table @samp
|
||
@item init
|
||
Evaluate expressions only once during the filter initialization.
|
||
|
||
@item frame
|
||
Evaluate expressions for each incoming frame. This is way slower than the
|
||
@samp{init} mode since it requires all the scalers to be re-computed, but it
|
||
allows advanced dynamic expressions.
|
||
@end table
|
||
|
||
Default value is @samp{init}.
|
||
|
||
@item dither
|
||
Set dithering to reduce the circular banding effects. Default is @code{1}
|
||
(enabled).
|
||
|
||
@item aspect
|
||
Set vignette aspect. This setting allows one to adjust the shape of the vignette.
|
||
Setting this value to the SAR of the input will make a rectangular vignetting
|
||
following the dimensions of the video.
|
||
|
||
Default is @code{1/1}.
|
||
@end table
|
||
|
||
@subsection Expressions
|
||
|
||
The @option{alpha}, @option{x0} and @option{y0} expressions can contain the
|
||
following parameters.
|
||
|
||
@table @option
|
||
@item w
|
||
@item h
|
||
input width and height
|
||
|
||
@item n
|
||
the number of input frame, starting from 0
|
||
|
||
@item pts
|
||
the PTS (Presentation TimeStamp) time of the filtered video frame, expressed in
|
||
@var{TB} units, NAN if undefined
|
||
|
||
@item r
|
||
frame rate of the input video, NAN if the input frame rate is unknown
|
||
|
||
@item t
|
||
the PTS (Presentation TimeStamp) of the filtered video frame,
|
||
expressed in seconds, NAN if undefined
|
||
|
||
@item tb
|
||
time base of the input video
|
||
@end table
|
||
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Apply simple strong vignetting effect:
|
||
@example
|
||
vignette=PI/4
|
||
@end example
|
||
|
||
@item
|
||
Make a flickering vignetting:
|
||
@example
|
||
vignette='PI/4+random(1)*PI/50':eval=frame
|
||
@end example
|
||
|
||
@end itemize
|
||
|
||
@section vstack
|
||
Stack input videos vertically.
|
||
|
||
All streams must be of same pixel format and of same width.
|
||
|
||
Note that this filter is faster than using @ref{overlay} and @ref{pad} filter
|
||
to create same output.
|
||
|
||
The filter accept the following option:
|
||
|
||
@table @option
|
||
@item inputs
|
||
Set number of input streams. Default is 2.
|
||
|
||
@item shortest
|
||
If set to 1, force the output to terminate when the shortest input
|
||
terminates. Default value is 0.
|
||
@end table
|
||
|
||
@section w3fdif
|
||
|
||
Deinterlace the input video ("w3fdif" stands for "Weston 3 Field
|
||
Deinterlacing Filter").
|
||
|
||
Based on the process described by Martin Weston for BBC R&D, and
|
||
implemented based on the de-interlace algorithm written by Jim
|
||
Easterbrook for BBC R&D, the Weston 3 field deinterlacing filter
|
||
uses filter coefficients calculated by BBC R&D.
|
||
|
||
There are two sets of filter coefficients, so called "simple":
|
||
and "complex". Which set of filter coefficients is used can
|
||
be set by passing an optional parameter:
|
||
|
||
@table @option
|
||
@item filter
|
||
Set the interlacing filter coefficients. Accepts one of the following values:
|
||
|
||
@table @samp
|
||
@item simple
|
||
Simple filter coefficient set.
|
||
@item complex
|
||
More-complex filter coefficient set.
|
||
@end table
|
||
Default value is @samp{complex}.
|
||
|
||
@item deint
|
||
Specify which frames to deinterlace. Accept one of the following values:
|
||
|
||
@table @samp
|
||
@item all
|
||
Deinterlace all frames,
|
||
@item interlaced
|
||
Only deinterlace frames marked as interlaced.
|
||
@end table
|
||
|
||
Default value is @samp{all}.
|
||
@end table
|
||
|
||
@section waveform
|
||
Video waveform monitor.
|
||
|
||
The waveform monitor plots color component intensity. By default luminance
|
||
only. Each column of the waveform corresponds to a column of pixels in the
|
||
source video.
|
||
|
||
It accepts the following options:
|
||
|
||
@table @option
|
||
@item mode, m
|
||
Can be either @code{row}, or @code{column}. Default is @code{column}.
|
||
In row mode, the graph on the left side represents color component value 0 and
|
||
the right side represents value = 255. In column mode, the top side represents
|
||
color component value = 0 and bottom side represents value = 255.
|
||
|
||
@item intensity, i
|
||
Set intensity. Smaller values are useful to find out how many values of the same
|
||
luminance are distributed across input rows/columns.
|
||
Default value is @code{0.04}. Allowed range is [0, 1].
|
||
|
||
@item mirror, r
|
||
Set mirroring mode. @code{0} means unmirrored, @code{1} means mirrored.
|
||
In mirrored mode, higher values will be represented on the left
|
||
side for @code{row} mode and at the top for @code{column} mode. Default is
|
||
@code{1} (mirrored).
|
||
|
||
@item display, d
|
||
Set display mode.
|
||
It accepts the following values:
|
||
@table @samp
|
||
@item overlay
|
||
Presents information identical to that in the @code{parade}, except
|
||
that the graphs representing color components are superimposed directly
|
||
over one another.
|
||
|
||
This display mode makes it easier to spot relative differences or similarities
|
||
in overlapping areas of the color components that are supposed to be identical,
|
||
such as neutral whites, grays, or blacks.
|
||
|
||
@item stack
|
||
Display separate graph for the color components side by side in
|
||
@code{row} mode or one below the other in @code{column} mode.
|
||
|
||
@item parade
|
||
Display separate graph for the color components side by side in
|
||
@code{column} mode or one below the other in @code{row} mode.
|
||
|
||
Using this display mode makes it easy to spot color casts in the highlights
|
||
and shadows of an image, by comparing the contours of the top and the bottom
|
||
graphs of each waveform. Since whites, grays, and blacks are characterized
|
||
by exactly equal amounts of red, green, and blue, neutral areas of the picture
|
||
should display three waveforms of roughly equal width/height. If not, the
|
||
correction is easy to perform by making level adjustments the three waveforms.
|
||
@end table
|
||
Default is @code{stack}.
|
||
|
||
@item components, c
|
||
Set which color components to display. Default is 1, which means only luminance
|
||
or red color component if input is in RGB colorspace. If is set for example to
|
||
7 it will display all 3 (if) available color components.
|
||
|
||
@item envelope, e
|
||
@table @samp
|
||
@item none
|
||
No envelope, this is default.
|
||
|
||
@item instant
|
||
Instant envelope, minimum and maximum values presented in graph will be easily
|
||
visible even with small @code{step} value.
|
||
|
||
@item peak
|
||
Hold minimum and maximum values presented in graph across time. This way you
|
||
can still spot out of range values without constantly looking at waveforms.
|
||
|
||
@item peak+instant
|
||
Peak and instant envelope combined together.
|
||
@end table
|
||
|
||
@item filter, f
|
||
@table @samp
|
||
@item lowpass
|
||
No filtering, this is default.
|
||
|
||
@item flat
|
||
Luma and chroma combined together.
|
||
|
||
@item aflat
|
||
Similar as above, but shows difference between blue and red chroma.
|
||
|
||
@item chroma
|
||
Displays only chroma.
|
||
|
||
@item color
|
||
Displays actual color value on waveform.
|
||
|
||
@item acolor
|
||
Similar as above, but with luma showing frequency of chroma values.
|
||
@end table
|
||
|
||
@item graticule, g
|
||
Set which graticule to display.
|
||
|
||
@table @samp
|
||
@item none
|
||
Do not display graticule.
|
||
|
||
@item green
|
||
Display green graticule showing legal broadcast ranges.
|
||
@end table
|
||
|
||
@item opacity, o
|
||
Set graticule opacity.
|
||
|
||
@item flags, fl
|
||
Set graticule flags.
|
||
|
||
@table @samp
|
||
@item numbers
|
||
Draw numbers above lines. By default enabled.
|
||
|
||
@item dots
|
||
Draw dots instead of lines.
|
||
@end table
|
||
|
||
@item scale, s
|
||
Set scale used for displaying graticule.
|
||
|
||
@table @samp
|
||
@item digital
|
||
@item millivolts
|
||
@item ire
|
||
@end table
|
||
Default is digital.
|
||
|
||
@item bgopacity, b
|
||
Set background opacity.
|
||
@end table
|
||
|
||
@section weave, doubleweave
|
||
|
||
The @code{weave} takes a field-based video input and join
|
||
each two sequential fields into single frame, producing a new double
|
||
height clip with half the frame rate and half the frame count.
|
||
|
||
The @code{doubleweave} works same as @code{weave} but without
|
||
halving frame rate and frame count.
|
||
|
||
It accepts the following option:
|
||
|
||
@table @option
|
||
@item first_field
|
||
Set first field. Available values are:
|
||
|
||
@table @samp
|
||
@item top, t
|
||
Set the frame as top-field-first.
|
||
|
||
@item bottom, b
|
||
Set the frame as bottom-field-first.
|
||
@end table
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Interlace video using @ref{select} and @ref{separatefields} filter:
|
||
@example
|
||
separatefields,select=eq(mod(n,4),0)+eq(mod(n,4),3),weave
|
||
@end example
|
||
@end itemize
|
||
|
||
@section xbr
|
||
Apply the xBR high-quality magnification filter which is designed for pixel
|
||
art. It follows a set of edge-detection rules, see
|
||
@url{http://www.libretro.com/forums/viewtopic.php?f=6&t=134}.
|
||
|
||
It accepts the following option:
|
||
|
||
@table @option
|
||
@item n
|
||
Set the scaling dimension: @code{2} for @code{2xBR}, @code{3} for
|
||
@code{3xBR} and @code{4} for @code{4xBR}.
|
||
Default is @code{3}.
|
||
@end table
|
||
|
||
@anchor{yadif}
|
||
@section yadif
|
||
|
||
Deinterlace the input video ("yadif" means "yet another deinterlacing
|
||
filter").
|
||
|
||
It accepts the following parameters:
|
||
|
||
|
||
@table @option
|
||
|
||
@item mode
|
||
The interlacing mode to adopt. It accepts one of the following values:
|
||
|
||
@table @option
|
||
@item 0, send_frame
|
||
Output one frame for each frame.
|
||
@item 1, send_field
|
||
Output one frame for each field.
|
||
@item 2, send_frame_nospatial
|
||
Like @code{send_frame}, but it skips the spatial interlacing check.
|
||
@item 3, send_field_nospatial
|
||
Like @code{send_field}, but it skips the spatial interlacing check.
|
||
@end table
|
||
|
||
The default value is @code{send_frame}.
|
||
|
||
@item parity
|
||
The picture field parity assumed for the input interlaced video. It accepts one
|
||
of the following values:
|
||
|
||
@table @option
|
||
@item 0, tff
|
||
Assume the top field is first.
|
||
@item 1, bff
|
||
Assume the bottom field is first.
|
||
@item -1, auto
|
||
Enable automatic detection of field parity.
|
||
@end table
|
||
|
||
The default value is @code{auto}.
|
||
If the interlacing is unknown or the decoder does not export this information,
|
||
top field first will be assumed.
|
||
|
||
@item deint
|
||
Specify which frames to deinterlace. Accept one of the following
|
||
values:
|
||
|
||
@table @option
|
||
@item 0, all
|
||
Deinterlace all frames.
|
||
@item 1, interlaced
|
||
Only deinterlace frames marked as interlaced.
|
||
@end table
|
||
|
||
The default value is @code{all}.
|
||
@end table
|
||
|
||
@section zoompan
|
||
|
||
Apply Zoom & Pan effect.
|
||
|
||
This filter accepts the following options:
|
||
|
||
@table @option
|
||
@item zoom, z
|
||
Set the zoom expression. Default is 1.
|
||
|
||
@item x
|
||
@item y
|
||
Set the x and y expression. Default is 0.
|
||
|
||
@item d
|
||
Set the duration expression in number of frames.
|
||
This sets for how many number of frames effect will last for
|
||
single input image.
|
||
|
||
@item s
|
||
Set the output image size, default is 'hd720'.
|
||
|
||
@item fps
|
||
Set the output frame rate, default is '25'.
|
||
@end table
|
||
|
||
Each expression can contain the following constants:
|
||
|
||
@table @option
|
||
@item in_w, iw
|
||
Input width.
|
||
|
||
@item in_h, ih
|
||
Input height.
|
||
|
||
@item out_w, ow
|
||
Output width.
|
||
|
||
@item out_h, oh
|
||
Output height.
|
||
|
||
@item in
|
||
Input frame count.
|
||
|
||
@item on
|
||
Output frame count.
|
||
|
||
@item x
|
||
@item y
|
||
Last calculated 'x' and 'y' position from 'x' and 'y' expression
|
||
for current input frame.
|
||
|
||
@item px
|
||
@item py
|
||
'x' and 'y' of last output frame of previous input frame or 0 when there was
|
||
not yet such frame (first input frame).
|
||
|
||
@item zoom
|
||
Last calculated zoom from 'z' expression for current input frame.
|
||
|
||
@item pzoom
|
||
Last calculated zoom of last output frame of previous input frame.
|
||
|
||
@item duration
|
||
Number of output frames for current input frame. Calculated from 'd' expression
|
||
for each input frame.
|
||
|
||
@item pduration
|
||
number of output frames created for previous input frame
|
||
|
||
@item a
|
||
Rational number: input width / input height
|
||
|
||
@item sar
|
||
sample aspect ratio
|
||
|
||
@item dar
|
||
display aspect ratio
|
||
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Zoom-in up to 1.5 and pan at same time to some spot near center of picture:
|
||
@example
|
||
zoompan=z='min(zoom+0.0015,1.5)':d=700:x='if(gte(zoom,1.5),x,x+1/a)':y='if(gte(zoom,1.5),y,y+1)':s=640x360
|
||
@end example
|
||
|
||
@item
|
||
Zoom-in up to 1.5 and pan always at center of picture:
|
||
@example
|
||
zoompan=z='min(zoom+0.0015,1.5)':d=700:x='iw/2-(iw/zoom/2)':y='ih/2-(ih/zoom/2)'
|
||
@end example
|
||
|
||
@item
|
||
Same as above but without pausing:
|
||
@example
|
||
zoompan=z='min(max(zoom,pzoom)+0.0015,1.5)':d=1:x='iw/2-(iw/zoom/2)':y='ih/2-(ih/zoom/2)'
|
||
@end example
|
||
@end itemize
|
||
|
||
@section zscale
|
||
Scale (resize) the input video, using the z.lib library:
|
||
https://github.com/sekrit-twc/zimg.
|
||
|
||
The zscale filter forces the output display aspect ratio to be the same
|
||
as the input, by changing the output sample aspect ratio.
|
||
|
||
If the input image format is different from the format requested by
|
||
the next filter, the zscale filter will convert the input to the
|
||
requested format.
|
||
|
||
@subsection Options
|
||
The filter accepts the following options.
|
||
|
||
@table @option
|
||
@item width, w
|
||
@item height, h
|
||
Set the output video dimension expression. Default value is the input
|
||
dimension.
|
||
|
||
If the @var{width} or @var{w} value is 0, the input width is used for
|
||
the output. If the @var{height} or @var{h} value is 0, the input height
|
||
is used for the output.
|
||
|
||
If one and only one of the values is -n with n >= 1, the zscale filter
|
||
will use a value that maintains the aspect ratio of the input image,
|
||
calculated from the other specified dimension. After that it will,
|
||
however, make sure that the calculated dimension is divisible by n and
|
||
adjust the value if necessary.
|
||
|
||
If both values are -n with n >= 1, the behavior will be identical to
|
||
both values being set to 0 as previously detailed.
|
||
|
||
See below for the list of accepted constants for use in the dimension
|
||
expression.
|
||
|
||
@item size, s
|
||
Set the video size. For the syntax of this option, check the
|
||
@ref{video size syntax,,"Video size" section in the ffmpeg-utils manual,ffmpeg-utils}.
|
||
|
||
@item dither, d
|
||
Set the dither type.
|
||
|
||
Possible values are:
|
||
@table @var
|
||
@item none
|
||
@item ordered
|
||
@item random
|
||
@item error_diffusion
|
||
@end table
|
||
|
||
Default is none.
|
||
|
||
@item filter, f
|
||
Set the resize filter type.
|
||
|
||
Possible values are:
|
||
@table @var
|
||
@item point
|
||
@item bilinear
|
||
@item bicubic
|
||
@item spline16
|
||
@item spline36
|
||
@item lanczos
|
||
@end table
|
||
|
||
Default is bilinear.
|
||
|
||
@item range, r
|
||
Set the color range.
|
||
|
||
Possible values are:
|
||
@table @var
|
||
@item input
|
||
@item limited
|
||
@item full
|
||
@end table
|
||
|
||
Default is same as input.
|
||
|
||
@item primaries, p
|
||
Set the color primaries.
|
||
|
||
Possible values are:
|
||
@table @var
|
||
@item input
|
||
@item 709
|
||
@item unspecified
|
||
@item 170m
|
||
@item 240m
|
||
@item 2020
|
||
@end table
|
||
|
||
Default is same as input.
|
||
|
||
@item transfer, t
|
||
Set the transfer characteristics.
|
||
|
||
Possible values are:
|
||
@table @var
|
||
@item input
|
||
@item 709
|
||
@item unspecified
|
||
@item 601
|
||
@item linear
|
||
@item 2020_10
|
||
@item 2020_12
|
||
@item smpte2084
|
||
@item iec61966-2-1
|
||
@item arib-std-b67
|
||
@end table
|
||
|
||
Default is same as input.
|
||
|
||
@item matrix, m
|
||
Set the colorspace matrix.
|
||
|
||
Possible value are:
|
||
@table @var
|
||
@item input
|
||
@item 709
|
||
@item unspecified
|
||
@item 470bg
|
||
@item 170m
|
||
@item 2020_ncl
|
||
@item 2020_cl
|
||
@end table
|
||
|
||
Default is same as input.
|
||
|
||
@item rangein, rin
|
||
Set the input color range.
|
||
|
||
Possible values are:
|
||
@table @var
|
||
@item input
|
||
@item limited
|
||
@item full
|
||
@end table
|
||
|
||
Default is same as input.
|
||
|
||
@item primariesin, pin
|
||
Set the input color primaries.
|
||
|
||
Possible values are:
|
||
@table @var
|
||
@item input
|
||
@item 709
|
||
@item unspecified
|
||
@item 170m
|
||
@item 240m
|
||
@item 2020
|
||
@end table
|
||
|
||
Default is same as input.
|
||
|
||
@item transferin, tin
|
||
Set the input transfer characteristics.
|
||
|
||
Possible values are:
|
||
@table @var
|
||
@item input
|
||
@item 709
|
||
@item unspecified
|
||
@item 601
|
||
@item linear
|
||
@item 2020_10
|
||
@item 2020_12
|
||
@end table
|
||
|
||
Default is same as input.
|
||
|
||
@item matrixin, min
|
||
Set the input colorspace matrix.
|
||
|
||
Possible value are:
|
||
@table @var
|
||
@item input
|
||
@item 709
|
||
@item unspecified
|
||
@item 470bg
|
||
@item 170m
|
||
@item 2020_ncl
|
||
@item 2020_cl
|
||
@end table
|
||
|
||
@item chromal, c
|
||
Set the output chroma location.
|
||
|
||
Possible values are:
|
||
@table @var
|
||
@item input
|
||
@item left
|
||
@item center
|
||
@item topleft
|
||
@item top
|
||
@item bottomleft
|
||
@item bottom
|
||
@end table
|
||
|
||
@item chromalin, cin
|
||
Set the input chroma location.
|
||
|
||
Possible values are:
|
||
@table @var
|
||
@item input
|
||
@item left
|
||
@item center
|
||
@item topleft
|
||
@item top
|
||
@item bottomleft
|
||
@item bottom
|
||
@end table
|
||
|
||
@item npl
|
||
Set the nominal peak luminance.
|
||
@end table
|
||
|
||
The values of the @option{w} and @option{h} options are expressions
|
||
containing the following constants:
|
||
|
||
@table @var
|
||
@item in_w
|
||
@item in_h
|
||
The input width and height
|
||
|
||
@item iw
|
||
@item ih
|
||
These are the same as @var{in_w} and @var{in_h}.
|
||
|
||
@item out_w
|
||
@item out_h
|
||
The output (scaled) width and height
|
||
|
||
@item ow
|
||
@item oh
|
||
These are the same as @var{out_w} and @var{out_h}
|
||
|
||
@item a
|
||
The same as @var{iw} / @var{ih}
|
||
|
||
@item sar
|
||
input sample aspect ratio
|
||
|
||
@item dar
|
||
The input display aspect ratio. Calculated from @code{(iw / ih) * sar}.
|
||
|
||
@item hsub
|
||
@item vsub
|
||
horizontal and vertical input chroma subsample values. For example for the
|
||
pixel format "yuv422p" @var{hsub} is 2 and @var{vsub} is 1.
|
||
|
||
@item ohsub
|
||
@item ovsub
|
||
horizontal and vertical output chroma subsample values. For example for the
|
||
pixel format "yuv422p" @var{hsub} is 2 and @var{vsub} is 1.
|
||
@end table
|
||
|
||
@table @option
|
||
@end table
|
||
|
||
@c man end VIDEO FILTERS
|
||
|
||
@chapter Video Sources
|
||
@c man begin VIDEO SOURCES
|
||
|
||
Below is a description of the currently available video sources.
|
||
|
||
@section buffer
|
||
|
||
Buffer video frames, and make them available to the filter chain.
|
||
|
||
This source is mainly intended for a programmatic use, in particular
|
||
through the interface defined in @file{libavfilter/vsrc_buffer.h}.
|
||
|
||
It accepts the following parameters:
|
||
|
||
@table @option
|
||
|
||
@item video_size
|
||
Specify the size (width and height) of the buffered video frames. For the
|
||
syntax of this option, check the
|
||
@ref{video size syntax,,"Video size" section in the ffmpeg-utils manual,ffmpeg-utils}.
|
||
|
||
@item width
|
||
The input video width.
|
||
|
||
@item height
|
||
The input video height.
|
||
|
||
@item pix_fmt
|
||
A string representing the pixel format of the buffered video frames.
|
||
It may be a number corresponding to a pixel format, or a pixel format
|
||
name.
|
||
|
||
@item time_base
|
||
Specify the timebase assumed by the timestamps of the buffered frames.
|
||
|
||
@item frame_rate
|
||
Specify the frame rate expected for the video stream.
|
||
|
||
@item pixel_aspect, sar
|
||
The sample (pixel) aspect ratio of the input video.
|
||
|
||
@item sws_param
|
||
Specify the optional parameters to be used for the scale filter which
|
||
is automatically inserted when an input change is detected in the
|
||
input size or format.
|
||
|
||
@item hw_frames_ctx
|
||
When using a hardware pixel format, this should be a reference to an
|
||
AVHWFramesContext describing input frames.
|
||
@end table
|
||
|
||
For example:
|
||
@example
|
||
buffer=width=320:height=240:pix_fmt=yuv410p:time_base=1/24:sar=1
|
||
@end example
|
||
|
||
will instruct the source to accept video frames with size 320x240 and
|
||
with format "yuv410p", assuming 1/24 as the timestamps timebase and
|
||
square pixels (1:1 sample aspect ratio).
|
||
Since the pixel format with name "yuv410p" corresponds to the number 6
|
||
(check the enum AVPixelFormat definition in @file{libavutil/pixfmt.h}),
|
||
this example corresponds to:
|
||
@example
|
||
buffer=size=320x240:pixfmt=6:time_base=1/24:pixel_aspect=1/1
|
||
@end example
|
||
|
||
Alternatively, the options can be specified as a flat string, but this
|
||
syntax is deprecated:
|
||
|
||
@var{width}:@var{height}:@var{pix_fmt}:@var{time_base.num}:@var{time_base.den}:@var{pixel_aspect.num}:@var{pixel_aspect.den}[:@var{sws_param}]
|
||
|
||
@section cellauto
|
||
|
||
Create a pattern generated by an elementary cellular automaton.
|
||
|
||
The initial state of the cellular automaton can be defined through the
|
||
@option{filename} and @option{pattern} options. If such options are
|
||
not specified an initial state is created randomly.
|
||
|
||
At each new frame a new row in the video is filled with the result of
|
||
the cellular automaton next generation. The behavior when the whole
|
||
frame is filled is defined by the @option{scroll} option.
|
||
|
||
This source accepts the following options:
|
||
|
||
@table @option
|
||
@item filename, f
|
||
Read the initial cellular automaton state, i.e. the starting row, from
|
||
the specified file.
|
||
In the file, each non-whitespace character is considered an alive
|
||
cell, a newline will terminate the row, and further characters in the
|
||
file will be ignored.
|
||
|
||
@item pattern, p
|
||
Read the initial cellular automaton state, i.e. the starting row, from
|
||
the specified string.
|
||
|
||
Each non-whitespace character in the string is considered an alive
|
||
cell, a newline will terminate the row, and further characters in the
|
||
string will be ignored.
|
||
|
||
@item rate, r
|
||
Set the video rate, that is the number of frames generated per second.
|
||
Default is 25.
|
||
|
||
@item random_fill_ratio, ratio
|
||
Set the random fill ratio for the initial cellular automaton row. It
|
||
is a floating point number value ranging from 0 to 1, defaults to
|
||
1/PHI.
|
||
|
||
This option is ignored when a file or a pattern is specified.
|
||
|
||
@item random_seed, seed
|
||
Set the seed for filling randomly the initial row, must be an integer
|
||
included between 0 and UINT32_MAX. If not specified, or if explicitly
|
||
set to -1, the filter will try to use a good random seed on a best
|
||
effort basis.
|
||
|
||
@item rule
|
||
Set the cellular automaton rule, it is a number ranging from 0 to 255.
|
||
Default value is 110.
|
||
|
||
@item size, s
|
||
Set the size of the output video. For the syntax of this option, check the
|
||
@ref{video size syntax,,"Video size" section in the ffmpeg-utils manual,ffmpeg-utils}.
|
||
|
||
If @option{filename} or @option{pattern} is specified, the size is set
|
||
by default to the width of the specified initial state row, and the
|
||
height is set to @var{width} * PHI.
|
||
|
||
If @option{size} is set, it must contain the width of the specified
|
||
pattern string, and the specified pattern will be centered in the
|
||
larger row.
|
||
|
||
If a filename or a pattern string is not specified, the size value
|
||
defaults to "320x518" (used for a randomly generated initial state).
|
||
|
||
@item scroll
|
||
If set to 1, scroll the output upward when all the rows in the output
|
||
have been already filled. If set to 0, the new generated row will be
|
||
written over the top row just after the bottom row is filled.
|
||
Defaults to 1.
|
||
|
||
@item start_full, full
|
||
If set to 1, completely fill the output with generated rows before
|
||
outputting the first frame.
|
||
This is the default behavior, for disabling set the value to 0.
|
||
|
||
@item stitch
|
||
If set to 1, stitch the left and right row edges together.
|
||
This is the default behavior, for disabling set the value to 0.
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Read the initial state from @file{pattern}, and specify an output of
|
||
size 200x400.
|
||
@example
|
||
cellauto=f=pattern:s=200x400
|
||
@end example
|
||
|
||
@item
|
||
Generate a random initial row with a width of 200 cells, with a fill
|
||
ratio of 2/3:
|
||
@example
|
||
cellauto=ratio=2/3:s=200x200
|
||
@end example
|
||
|
||
@item
|
||
Create a pattern generated by rule 18 starting by a single alive cell
|
||
centered on an initial row with width 100:
|
||
@example
|
||
cellauto=p=@@:s=100x400:full=0:rule=18
|
||
@end example
|
||
|
||
@item
|
||
Specify a more elaborated initial pattern:
|
||
@example
|
||
cellauto=p='@@@@ @@ @@@@':s=100x400:full=0:rule=18
|
||
@end example
|
||
|
||
@end itemize
|
||
|
||
@anchor{coreimagesrc}
|
||
@section coreimagesrc
|
||
Video source generated on GPU using Apple's CoreImage API on OSX.
|
||
|
||
This video source is a specialized version of the @ref{coreimage} video filter.
|
||
Use a core image generator at the beginning of the applied filterchain to
|
||
generate the content.
|
||
|
||
The coreimagesrc video source accepts the following options:
|
||
@table @option
|
||
@item list_generators
|
||
List all available generators along with all their respective options as well as
|
||
possible minimum and maximum values along with the default values.
|
||
@example
|
||
list_generators=true
|
||
@end example
|
||
|
||
@item size, s
|
||
Specify the size of the sourced video. For the syntax of this option, check the
|
||
@ref{video size syntax,,"Video size" section in the ffmpeg-utils manual,ffmpeg-utils}.
|
||
The default value is @code{320x240}.
|
||
|
||
@item rate, r
|
||
Specify the frame rate of the sourced video, as the number of frames
|
||
generated per second. It has to be a string in the format
|
||
@var{frame_rate_num}/@var{frame_rate_den}, an integer number, a floating point
|
||
number or a valid video frame rate abbreviation. The default value is
|
||
"25".
|
||
|
||
@item sar
|
||
Set the sample aspect ratio of the sourced video.
|
||
|
||
@item duration, d
|
||
Set the duration of the sourced video. See
|
||
@ref{time duration syntax,,the Time duration section in the ffmpeg-utils(1) manual,ffmpeg-utils}
|
||
for the accepted syntax.
|
||
|
||
If not specified, or the expressed duration is negative, the video is
|
||
supposed to be generated forever.
|
||
@end table
|
||
|
||
Additionally, all options of the @ref{coreimage} video filter are accepted.
|
||
A complete filterchain can be used for further processing of the
|
||
generated input without CPU-HOST transfer. See @ref{coreimage} documentation
|
||
and examples for details.
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
|
||
@item
|
||
Use CIQRCodeGenerator to create a QR code for the FFmpeg homepage,
|
||
given as complete and escaped command-line for Apple's standard bash shell:
|
||
@example
|
||
ffmpeg -f lavfi -i coreimagesrc=s=100x100:filter=CIQRCodeGenerator@@inputMessage=https\\\\\://FFmpeg.org/@@inputCorrectionLevel=H -frames:v 1 QRCode.png
|
||
@end example
|
||
This example is equivalent to the QRCode example of @ref{coreimage} without the
|
||
need for a nullsrc video source.
|
||
@end itemize
|
||
|
||
|
||
@section mandelbrot
|
||
|
||
Generate a Mandelbrot set fractal, and progressively zoom towards the
|
||
point specified with @var{start_x} and @var{start_y}.
|
||
|
||
This source accepts the following options:
|
||
|
||
@table @option
|
||
|
||
@item end_pts
|
||
Set the terminal pts value. Default value is 400.
|
||
|
||
@item end_scale
|
||
Set the terminal scale value.
|
||
Must be a floating point value. Default value is 0.3.
|
||
|
||
@item inner
|
||
Set the inner coloring mode, that is the algorithm used to draw the
|
||
Mandelbrot fractal internal region.
|
||
|
||
It shall assume one of the following values:
|
||
@table @option
|
||
@item black
|
||
Set black mode.
|
||
@item convergence
|
||
Show time until convergence.
|
||
@item mincol
|
||
Set color based on point closest to the origin of the iterations.
|
||
@item period
|
||
Set period mode.
|
||
@end table
|
||
|
||
Default value is @var{mincol}.
|
||
|
||
@item bailout
|
||
Set the bailout value. Default value is 10.0.
|
||
|
||
@item maxiter
|
||
Set the maximum of iterations performed by the rendering
|
||
algorithm. Default value is 7189.
|
||
|
||
@item outer
|
||
Set outer coloring mode.
|
||
It shall assume one of following values:
|
||
@table @option
|
||
@item iteration_count
|
||
Set iteration cound mode.
|
||
@item normalized_iteration_count
|
||
set normalized iteration count mode.
|
||
@end table
|
||
Default value is @var{normalized_iteration_count}.
|
||
|
||
@item rate, r
|
||
Set frame rate, expressed as number of frames per second. Default
|
||
value is "25".
|
||
|
||
@item size, s
|
||
Set frame size. For the syntax of this option, check the "Video
|
||
size" section in the ffmpeg-utils manual. Default value is "640x480".
|
||
|
||
@item start_scale
|
||
Set the initial scale value. Default value is 3.0.
|
||
|
||
@item start_x
|
||
Set the initial x position. Must be a floating point value between
|
||
-100 and 100. Default value is -0.743643887037158704752191506114774.
|
||
|
||
@item start_y
|
||
Set the initial y position. Must be a floating point value between
|
||
-100 and 100. Default value is -0.131825904205311970493132056385139.
|
||
@end table
|
||
|
||
@section mptestsrc
|
||
|
||
Generate various test patterns, as generated by the MPlayer test filter.
|
||
|
||
The size of the generated video is fixed, and is 256x256.
|
||
This source is useful in particular for testing encoding features.
|
||
|
||
This source accepts the following options:
|
||
|
||
@table @option
|
||
|
||
@item rate, r
|
||
Specify the frame rate of the sourced video, as the number of frames
|
||
generated per second. It has to be a string in the format
|
||
@var{frame_rate_num}/@var{frame_rate_den}, an integer number, a floating point
|
||
number or a valid video frame rate abbreviation. The default value is
|
||
"25".
|
||
|
||
@item duration, d
|
||
Set the duration of the sourced video. See
|
||
@ref{time duration syntax,,the Time duration section in the ffmpeg-utils(1) manual,ffmpeg-utils}
|
||
for the accepted syntax.
|
||
|
||
If not specified, or the expressed duration is negative, the video is
|
||
supposed to be generated forever.
|
||
|
||
@item test, t
|
||
|
||
Set the number or the name of the test to perform. Supported tests are:
|
||
@table @option
|
||
@item dc_luma
|
||
@item dc_chroma
|
||
@item freq_luma
|
||
@item freq_chroma
|
||
@item amp_luma
|
||
@item amp_chroma
|
||
@item cbp
|
||
@item mv
|
||
@item ring1
|
||
@item ring2
|
||
@item all
|
||
|
||
@end table
|
||
|
||
Default value is "all", which will cycle through the list of all tests.
|
||
@end table
|
||
|
||
Some examples:
|
||
@example
|
||
mptestsrc=t=dc_luma
|
||
@end example
|
||
|
||
will generate a "dc_luma" test pattern.
|
||
|
||
@section frei0r_src
|
||
|
||
Provide a frei0r source.
|
||
|
||
To enable compilation of this filter you need to install the frei0r
|
||
header and configure FFmpeg with @code{--enable-frei0r}.
|
||
|
||
This source accepts the following parameters:
|
||
|
||
@table @option
|
||
|
||
@item size
|
||
The size of the video to generate. For the syntax of this option, check the
|
||
@ref{video size syntax,,"Video size" section in the ffmpeg-utils manual,ffmpeg-utils}.
|
||
|
||
@item framerate
|
||
The framerate of the generated video. It may be a string of the form
|
||
@var{num}/@var{den} or a frame rate abbreviation.
|
||
|
||
@item filter_name
|
||
The name to the frei0r source to load. For more information regarding frei0r and
|
||
how to set the parameters, read the @ref{frei0r} section in the video filters
|
||
documentation.
|
||
|
||
@item filter_params
|
||
A '|'-separated list of parameters to pass to the frei0r source.
|
||
|
||
@end table
|
||
|
||
For example, to generate a frei0r partik0l source with size 200x200
|
||
and frame rate 10 which is overlaid on the overlay filter main input:
|
||
@example
|
||
frei0r_src=size=200x200:framerate=10:filter_name=partik0l:filter_params=1234 [overlay]; [in][overlay] overlay
|
||
@end example
|
||
|
||
@section life
|
||
|
||
Generate a life pattern.
|
||
|
||
This source is based on a generalization of John Conway's life game.
|
||
|
||
The sourced input represents a life grid, each pixel represents a cell
|
||
which can be in one of two possible states, alive or dead. Every cell
|
||
interacts with its eight neighbours, which are the cells that are
|
||
horizontally, vertically, or diagonally adjacent.
|
||
|
||
At each interaction the grid evolves according to the adopted rule,
|
||
which specifies the number of neighbor alive cells which will make a
|
||
cell stay alive or born. The @option{rule} option allows one to specify
|
||
the rule to adopt.
|
||
|
||
This source accepts the following options:
|
||
|
||
@table @option
|
||
@item filename, f
|
||
Set the file from which to read the initial grid state. In the file,
|
||
each non-whitespace character is considered an alive cell, and newline
|
||
is used to delimit the end of each row.
|
||
|
||
If this option is not specified, the initial grid is generated
|
||
randomly.
|
||
|
||
@item rate, r
|
||
Set the video rate, that is the number of frames generated per second.
|
||
Default is 25.
|
||
|
||
@item random_fill_ratio, ratio
|
||
Set the random fill ratio for the initial random grid. It is a
|
||
floating point number value ranging from 0 to 1, defaults to 1/PHI.
|
||
It is ignored when a file is specified.
|
||
|
||
@item random_seed, seed
|
||
Set the seed for filling the initial random grid, must be an integer
|
||
included between 0 and UINT32_MAX. If not specified, or if explicitly
|
||
set to -1, the filter will try to use a good random seed on a best
|
||
effort basis.
|
||
|
||
@item rule
|
||
Set the life rule.
|
||
|
||
A rule can be specified with a code of the kind "S@var{NS}/B@var{NB}",
|
||
where @var{NS} and @var{NB} are sequences of numbers in the range 0-8,
|
||
@var{NS} specifies the number of alive neighbor cells which make a
|
||
live cell stay alive, and @var{NB} the number of alive neighbor cells
|
||
which make a dead cell to become alive (i.e. to "born").
|
||
"s" and "b" can be used in place of "S" and "B", respectively.
|
||
|
||
Alternatively a rule can be specified by an 18-bits integer. The 9
|
||
high order bits are used to encode the next cell state if it is alive
|
||
for each number of neighbor alive cells, the low order bits specify
|
||
the rule for "borning" new cells. Higher order bits encode for an
|
||
higher number of neighbor cells.
|
||
For example the number 6153 = @code{(12<<9)+9} specifies a stay alive
|
||
rule of 12 and a born rule of 9, which corresponds to "S23/B03".
|
||
|
||
Default value is "S23/B3", which is the original Conway's game of life
|
||
rule, and will keep a cell alive if it has 2 or 3 neighbor alive
|
||
cells, and will born a new cell if there are three alive cells around
|
||
a dead cell.
|
||
|
||
@item size, s
|
||
Set the size of the output video. For the syntax of this option, check the
|
||
@ref{video size syntax,,"Video size" section in the ffmpeg-utils manual,ffmpeg-utils}.
|
||
|
||
If @option{filename} is specified, the size is set by default to the
|
||
same size of the input file. If @option{size} is set, it must contain
|
||
the size specified in the input file, and the initial grid defined in
|
||
that file is centered in the larger resulting area.
|
||
|
||
If a filename is not specified, the size value defaults to "320x240"
|
||
(used for a randomly generated initial grid).
|
||
|
||
@item stitch
|
||
If set to 1, stitch the left and right grid edges together, and the
|
||
top and bottom edges also. Defaults to 1.
|
||
|
||
@item mold
|
||
Set cell mold speed. If set, a dead cell will go from @option{death_color} to
|
||
@option{mold_color} with a step of @option{mold}. @option{mold} can have a
|
||
value from 0 to 255.
|
||
|
||
@item life_color
|
||
Set the color of living (or new born) cells.
|
||
|
||
@item death_color
|
||
Set the color of dead cells. If @option{mold} is set, this is the first color
|
||
used to represent a dead cell.
|
||
|
||
@item mold_color
|
||
Set mold color, for definitely dead and moldy cells.
|
||
|
||
For the syntax of these 3 color options, check the "Color" section in the
|
||
ffmpeg-utils manual.
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Read a grid from @file{pattern}, and center it on a grid of size
|
||
300x300 pixels:
|
||
@example
|
||
life=f=pattern:s=300x300
|
||
@end example
|
||
|
||
@item
|
||
Generate a random grid of size 200x200, with a fill ratio of 2/3:
|
||
@example
|
||
life=ratio=2/3:s=200x200
|
||
@end example
|
||
|
||
@item
|
||
Specify a custom rule for evolving a randomly generated grid:
|
||
@example
|
||
life=rule=S14/B34
|
||
@end example
|
||
|
||
@item
|
||
Full example with slow death effect (mold) using @command{ffplay}:
|
||
@example
|
||
ffplay -f lavfi life=s=300x200:mold=10:r=60:ratio=0.1:death_color=#C83232:life_color=#00ff00,scale=1200:800:flags=16
|
||
@end example
|
||
@end itemize
|
||
|
||
@anchor{allrgb}
|
||
@anchor{allyuv}
|
||
@anchor{color}
|
||
@anchor{haldclutsrc}
|
||
@anchor{nullsrc}
|
||
@anchor{rgbtestsrc}
|
||
@anchor{smptebars}
|
||
@anchor{smptehdbars}
|
||
@anchor{testsrc}
|
||
@anchor{testsrc2}
|
||
@anchor{yuvtestsrc}
|
||
@section allrgb, allyuv, color, haldclutsrc, nullsrc, rgbtestsrc, smptebars, smptehdbars, testsrc, testsrc2, yuvtestsrc
|
||
|
||
The @code{allrgb} source returns frames of size 4096x4096 of all rgb colors.
|
||
|
||
The @code{allyuv} source returns frames of size 4096x4096 of all yuv colors.
|
||
|
||
The @code{color} source provides an uniformly colored input.
|
||
|
||
The @code{haldclutsrc} source provides an identity Hald CLUT. See also
|
||
@ref{haldclut} filter.
|
||
|
||
The @code{nullsrc} source returns unprocessed video frames. It is
|
||
mainly useful to be employed in analysis / debugging tools, or as the
|
||
source for filters which ignore the input data.
|
||
|
||
The @code{rgbtestsrc} source generates an RGB test pattern useful for
|
||
detecting RGB vs BGR issues. You should see a red, green and blue
|
||
stripe from top to bottom.
|
||
|
||
The @code{smptebars} source generates a color bars pattern, based on
|
||
the SMPTE Engineering Guideline EG 1-1990.
|
||
|
||
The @code{smptehdbars} source generates a color bars pattern, based on
|
||
the SMPTE RP 219-2002.
|
||
|
||
The @code{testsrc} source generates a test video pattern, showing a
|
||
color pattern, a scrolling gradient and a timestamp. This is mainly
|
||
intended for testing purposes.
|
||
|
||
The @code{testsrc2} source is similar to testsrc, but supports more
|
||
pixel formats instead of just @code{rgb24}. This allows using it as an
|
||
input for other tests without requiring a format conversion.
|
||
|
||
The @code{yuvtestsrc} source generates an YUV test pattern. You should
|
||
see a y, cb and cr stripe from top to bottom.
|
||
|
||
The sources accept the following parameters:
|
||
|
||
@table @option
|
||
|
||
@item alpha
|
||
Specify the alpha (opacity) of the background, only available in the
|
||
@code{testsrc2} source. The value must be between 0 (fully transparent) and
|
||
255 (fully opaque, the default).
|
||
|
||
@item color, c
|
||
Specify the color of the source, only available in the @code{color}
|
||
source. For the syntax of this option, check the "Color" section in the
|
||
ffmpeg-utils manual.
|
||
|
||
@item level
|
||
Specify the level of the Hald CLUT, only available in the @code{haldclutsrc}
|
||
source. A level of @code{N} generates a picture of @code{N*N*N} by @code{N*N*N}
|
||
pixels to be used as identity matrix for 3D lookup tables. Each component is
|
||
coded on a @code{1/(N*N)} scale.
|
||
|
||
@item size, s
|
||
Specify the size of the sourced video. For the syntax of this option, check the
|
||
@ref{video size syntax,,"Video size" section in the ffmpeg-utils manual,ffmpeg-utils}.
|
||
The default value is @code{320x240}.
|
||
|
||
This option is not available with the @code{haldclutsrc} filter.
|
||
|
||
@item rate, r
|
||
Specify the frame rate of the sourced video, as the number of frames
|
||
generated per second. It has to be a string in the format
|
||
@var{frame_rate_num}/@var{frame_rate_den}, an integer number, a floating point
|
||
number or a valid video frame rate abbreviation. The default value is
|
||
"25".
|
||
|
||
@item sar
|
||
Set the sample aspect ratio of the sourced video.
|
||
|
||
@item duration, d
|
||
Set the duration of the sourced video. See
|
||
@ref{time duration syntax,,the Time duration section in the ffmpeg-utils(1) manual,ffmpeg-utils}
|
||
for the accepted syntax.
|
||
|
||
If not specified, or the expressed duration is negative, the video is
|
||
supposed to be generated forever.
|
||
|
||
@item decimals, n
|
||
Set the number of decimals to show in the timestamp, only available in the
|
||
@code{testsrc} source.
|
||
|
||
The displayed timestamp value will correspond to the original
|
||
timestamp value multiplied by the power of 10 of the specified
|
||
value. Default value is 0.
|
||
@end table
|
||
|
||
For example the following:
|
||
@example
|
||
testsrc=duration=5.3:size=qcif:rate=10
|
||
@end example
|
||
|
||
will generate a video with a duration of 5.3 seconds, with size
|
||
176x144 and a frame rate of 10 frames per second.
|
||
|
||
The following graph description will generate a red source
|
||
with an opacity of 0.2, with size "qcif" and a frame rate of 10
|
||
frames per second.
|
||
@example
|
||
color=c=red@@0.2:s=qcif:r=10
|
||
@end example
|
||
|
||
If the input content is to be ignored, @code{nullsrc} can be used. The
|
||
following command generates noise in the luminance plane by employing
|
||
the @code{geq} filter:
|
||
@example
|
||
nullsrc=s=256x256, geq=random(1)*255:128:128
|
||
@end example
|
||
|
||
@subsection Commands
|
||
|
||
The @code{color} source supports the following commands:
|
||
|
||
@table @option
|
||
@item c, color
|
||
Set the color of the created image. Accepts the same syntax of the
|
||
corresponding @option{color} option.
|
||
@end table
|
||
|
||
@c man end VIDEO SOURCES
|
||
|
||
@chapter Video Sinks
|
||
@c man begin VIDEO SINKS
|
||
|
||
Below is a description of the currently available video sinks.
|
||
|
||
@section buffersink
|
||
|
||
Buffer video frames, and make them available to the end of the filter
|
||
graph.
|
||
|
||
This sink is mainly intended for programmatic use, in particular
|
||
through the interface defined in @file{libavfilter/buffersink.h}
|
||
or the options system.
|
||
|
||
It accepts a pointer to an AVBufferSinkContext structure, which
|
||
defines the incoming buffers' formats, to be passed as the opaque
|
||
parameter to @code{avfilter_init_filter} for initialization.
|
||
|
||
@section nullsink
|
||
|
||
Null video sink: do absolutely nothing with the input video. It is
|
||
mainly useful as a template and for use in analysis / debugging
|
||
tools.
|
||
|
||
@c man end VIDEO SINKS
|
||
|
||
@chapter Multimedia Filters
|
||
@c man begin MULTIMEDIA FILTERS
|
||
|
||
Below is a description of the currently available multimedia filters.
|
||
|
||
@section abitscope
|
||
|
||
Convert input audio to a video output, displaying the audio bit scope.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item rate, r
|
||
Set frame rate, expressed as number of frames per second. Default
|
||
value is "25".
|
||
|
||
@item size, s
|
||
Specify the video size for the output. For the syntax of this option, check the
|
||
@ref{video size syntax,,"Video size" section in the ffmpeg-utils manual,ffmpeg-utils}.
|
||
Default value is @code{1024x256}.
|
||
|
||
@item colors
|
||
Specify list of colors separated by space or by '|' which will be used to
|
||
draw channels. Unrecognized or missing colors will be replaced
|
||
by white color.
|
||
@end table
|
||
|
||
@section ahistogram
|
||
|
||
Convert input audio to a video output, displaying the volume histogram.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item dmode
|
||
Specify how histogram is calculated.
|
||
|
||
It accepts the following values:
|
||
@table @samp
|
||
@item single
|
||
Use single histogram for all channels.
|
||
@item separate
|
||
Use separate histogram for each channel.
|
||
@end table
|
||
Default is @code{single}.
|
||
|
||
@item rate, r
|
||
Set frame rate, expressed as number of frames per second. Default
|
||
value is "25".
|
||
|
||
@item size, s
|
||
Specify the video size for the output. For the syntax of this option, check the
|
||
@ref{video size syntax,,"Video size" section in the ffmpeg-utils manual,ffmpeg-utils}.
|
||
Default value is @code{hd720}.
|
||
|
||
@item scale
|
||
Set display scale.
|
||
|
||
It accepts the following values:
|
||
@table @samp
|
||
@item log
|
||
logarithmic
|
||
@item sqrt
|
||
square root
|
||
@item cbrt
|
||
cubic root
|
||
@item lin
|
||
linear
|
||
@item rlog
|
||
reverse logarithmic
|
||
@end table
|
||
Default is @code{log}.
|
||
|
||
@item ascale
|
||
Set amplitude scale.
|
||
|
||
It accepts the following values:
|
||
@table @samp
|
||
@item log
|
||
logarithmic
|
||
@item lin
|
||
linear
|
||
@end table
|
||
Default is @code{log}.
|
||
|
||
@item acount
|
||
Set how much frames to accumulate in histogram.
|
||
Defauls is 1. Setting this to -1 accumulates all frames.
|
||
|
||
@item rheight
|
||
Set histogram ratio of window height.
|
||
|
||
@item slide
|
||
Set sonogram sliding.
|
||
|
||
It accepts the following values:
|
||
@table @samp
|
||
@item replace
|
||
replace old rows with new ones.
|
||
@item scroll
|
||
scroll from top to bottom.
|
||
@end table
|
||
Default is @code{replace}.
|
||
@end table
|
||
|
||
@section aphasemeter
|
||
|
||
Convert input audio to a video output, displaying the audio phase.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item rate, r
|
||
Set the output frame rate. Default value is @code{25}.
|
||
|
||
@item size, s
|
||
Set the video size for the output. For the syntax of this option, check the
|
||
@ref{video size syntax,,"Video size" section in the ffmpeg-utils manual,ffmpeg-utils}.
|
||
Default value is @code{800x400}.
|
||
|
||
@item rc
|
||
@item gc
|
||
@item bc
|
||
Specify the red, green, blue contrast. Default values are @code{2},
|
||
@code{7} and @code{1}.
|
||
Allowed range is @code{[0, 255]}.
|
||
|
||
@item mpc
|
||
Set color which will be used for drawing median phase. If color is
|
||
@code{none} which is default, no median phase value will be drawn.
|
||
|
||
@item video
|
||
Enable video output. Default is enabled.
|
||
@end table
|
||
|
||
The filter also exports the frame metadata @code{lavfi.aphasemeter.phase} which
|
||
represents mean phase of current audio frame. Value is in range @code{[-1, 1]}.
|
||
The @code{-1} means left and right channels are completely out of phase and
|
||
@code{1} means channels are in phase.
|
||
|
||
@section avectorscope
|
||
|
||
Convert input audio to a video output, representing the audio vector
|
||
scope.
|
||
|
||
The filter is used to measure the difference between channels of stereo
|
||
audio stream. A monoaural signal, consisting of identical left and right
|
||
signal, results in straight vertical line. Any stereo separation is visible
|
||
as a deviation from this line, creating a Lissajous figure.
|
||
If the straight (or deviation from it) but horizontal line appears this
|
||
indicates that the left and right channels are out of phase.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item mode, m
|
||
Set the vectorscope mode.
|
||
|
||
Available values are:
|
||
@table @samp
|
||
@item lissajous
|
||
Lissajous rotated by 45 degrees.
|
||
|
||
@item lissajous_xy
|
||
Same as above but not rotated.
|
||
|
||
@item polar
|
||
Shape resembling half of circle.
|
||
@end table
|
||
|
||
Default value is @samp{lissajous}.
|
||
|
||
@item size, s
|
||
Set the video size for the output. For the syntax of this option, check the
|
||
@ref{video size syntax,,"Video size" section in the ffmpeg-utils manual,ffmpeg-utils}.
|
||
Default value is @code{400x400}.
|
||
|
||
@item rate, r
|
||
Set the output frame rate. Default value is @code{25}.
|
||
|
||
@item rc
|
||
@item gc
|
||
@item bc
|
||
@item ac
|
||
Specify the red, green, blue and alpha contrast. Default values are @code{40},
|
||
@code{160}, @code{80} and @code{255}.
|
||
Allowed range is @code{[0, 255]}.
|
||
|
||
@item rf
|
||
@item gf
|
||
@item bf
|
||
@item af
|
||
Specify the red, green, blue and alpha fade. Default values are @code{15},
|
||
@code{10}, @code{5} and @code{5}.
|
||
Allowed range is @code{[0, 255]}.
|
||
|
||
@item zoom
|
||
Set the zoom factor. Default value is @code{1}. Allowed range is @code{[1, 10]}.
|
||
|
||
@item draw
|
||
Set the vectorscope drawing mode.
|
||
|
||
Available values are:
|
||
@table @samp
|
||
@item dot
|
||
Draw dot for each sample.
|
||
|
||
@item line
|
||
Draw line between previous and current sample.
|
||
@end table
|
||
|
||
Default value is @samp{dot}.
|
||
|
||
@item scale
|
||
Specify amplitude scale of audio samples.
|
||
|
||
Available values are:
|
||
@table @samp
|
||
@item lin
|
||
Linear.
|
||
|
||
@item sqrt
|
||
Square root.
|
||
|
||
@item cbrt
|
||
Cubic root.
|
||
|
||
@item log
|
||
Logarithmic.
|
||
@end table
|
||
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Complete example using @command{ffplay}:
|
||
@example
|
||
ffplay -f lavfi 'amovie=input.mp3, asplit [a][out1];
|
||
[a] avectorscope=zoom=1.3:rc=2:gc=200:bc=10:rf=1:gf=8:bf=7 [out0]'
|
||
@end example
|
||
@end itemize
|
||
|
||
@section bench, abench
|
||
|
||
Benchmark part of a filtergraph.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item action
|
||
Start or stop a timer.
|
||
|
||
Available values are:
|
||
@table @samp
|
||
@item start
|
||
Get the current time, set it as frame metadata (using the key
|
||
@code{lavfi.bench.start_time}), and forward the frame to the next filter.
|
||
|
||
@item stop
|
||
Get the current time and fetch the @code{lavfi.bench.start_time} metadata from
|
||
the input frame metadata to get the time difference. Time difference, average,
|
||
maximum and minimum time (respectively @code{t}, @code{avg}, @code{max} and
|
||
@code{min}) are then printed. The timestamps are expressed in seconds.
|
||
@end table
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Benchmark @ref{selectivecolor} filter:
|
||
@example
|
||
bench=start,selectivecolor=reds=-.2 .12 -.49,bench=stop
|
||
@end example
|
||
@end itemize
|
||
|
||
@section concat
|
||
|
||
Concatenate audio and video streams, joining them together one after the
|
||
other.
|
||
|
||
The filter works on segments of synchronized video and audio streams. All
|
||
segments must have the same number of streams of each type, and that will
|
||
also be the number of streams at output.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
|
||
@item n
|
||
Set the number of segments. Default is 2.
|
||
|
||
@item v
|
||
Set the number of output video streams, that is also the number of video
|
||
streams in each segment. Default is 1.
|
||
|
||
@item a
|
||
Set the number of output audio streams, that is also the number of audio
|
||
streams in each segment. Default is 0.
|
||
|
||
@item unsafe
|
||
Activate unsafe mode: do not fail if segments have a different format.
|
||
|
||
@end table
|
||
|
||
The filter has @var{v}+@var{a} outputs: first @var{v} video outputs, then
|
||
@var{a} audio outputs.
|
||
|
||
There are @var{n}x(@var{v}+@var{a}) inputs: first the inputs for the first
|
||
segment, in the same order as the outputs, then the inputs for the second
|
||
segment, etc.
|
||
|
||
Related streams do not always have exactly the same duration, for various
|
||
reasons including codec frame size or sloppy authoring. For that reason,
|
||
related synchronized streams (e.g. a video and its audio track) should be
|
||
concatenated at once. The concat filter will use the duration of the longest
|
||
stream in each segment (except the last one), and if necessary pad shorter
|
||
audio streams with silence.
|
||
|
||
For this filter to work correctly, all segments must start at timestamp 0.
|
||
|
||
All corresponding streams must have the same parameters in all segments; the
|
||
filtering system will automatically select a common pixel format for video
|
||
streams, and a common sample format, sample rate and channel layout for
|
||
audio streams, but other settings, such as resolution, must be converted
|
||
explicitly by the user.
|
||
|
||
Different frame rates are acceptable but will result in variable frame rate
|
||
at output; be sure to configure the output file to handle it.
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Concatenate an opening, an episode and an ending, all in bilingual version
|
||
(video in stream 0, audio in streams 1 and 2):
|
||
@example
|
||
ffmpeg -i opening.mkv -i episode.mkv -i ending.mkv -filter_complex \
|
||
'[0:0] [0:1] [0:2] [1:0] [1:1] [1:2] [2:0] [2:1] [2:2]
|
||
concat=n=3:v=1:a=2 [v] [a1] [a2]' \
|
||
-map '[v]' -map '[a1]' -map '[a2]' output.mkv
|
||
@end example
|
||
|
||
@item
|
||
Concatenate two parts, handling audio and video separately, using the
|
||
(a)movie sources, and adjusting the resolution:
|
||
@example
|
||
movie=part1.mp4, scale=512:288 [v1] ; amovie=part1.mp4 [a1] ;
|
||
movie=part2.mp4, scale=512:288 [v2] ; amovie=part2.mp4 [a2] ;
|
||
[v1] [v2] concat [outv] ; [a1] [a2] concat=v=0:a=1 [outa]
|
||
@end example
|
||
Note that a desync will happen at the stitch if the audio and video streams
|
||
do not have exactly the same duration in the first file.
|
||
|
||
@end itemize
|
||
|
||
@section drawgraph, adrawgraph
|
||
|
||
Draw a graph using input video or audio metadata.
|
||
|
||
It accepts the following parameters:
|
||
|
||
@table @option
|
||
@item m1
|
||
Set 1st frame metadata key from which metadata values will be used to draw a graph.
|
||
|
||
@item fg1
|
||
Set 1st foreground color expression.
|
||
|
||
@item m2
|
||
Set 2nd frame metadata key from which metadata values will be used to draw a graph.
|
||
|
||
@item fg2
|
||
Set 2nd foreground color expression.
|
||
|
||
@item m3
|
||
Set 3rd frame metadata key from which metadata values will be used to draw a graph.
|
||
|
||
@item fg3
|
||
Set 3rd foreground color expression.
|
||
|
||
@item m4
|
||
Set 4th frame metadata key from which metadata values will be used to draw a graph.
|
||
|
||
@item fg4
|
||
Set 4th foreground color expression.
|
||
|
||
@item min
|
||
Set minimal value of metadata value.
|
||
|
||
@item max
|
||
Set maximal value of metadata value.
|
||
|
||
@item bg
|
||
Set graph background color. Default is white.
|
||
|
||
@item mode
|
||
Set graph mode.
|
||
|
||
Available values for mode is:
|
||
@table @samp
|
||
@item bar
|
||
@item dot
|
||
@item line
|
||
@end table
|
||
|
||
Default is @code{line}.
|
||
|
||
@item slide
|
||
Set slide mode.
|
||
|
||
Available values for slide is:
|
||
@table @samp
|
||
@item frame
|
||
Draw new frame when right border is reached.
|
||
|
||
@item replace
|
||
Replace old columns with new ones.
|
||
|
||
@item scroll
|
||
Scroll from right to left.
|
||
|
||
@item rscroll
|
||
Scroll from left to right.
|
||
|
||
@item picture
|
||
Draw single picture.
|
||
@end table
|
||
|
||
Default is @code{frame}.
|
||
|
||
@item size
|
||
Set size of graph video. For the syntax of this option, check the
|
||
@ref{video size syntax,,"Video size" section in the ffmpeg-utils manual,ffmpeg-utils}.
|
||
The default value is @code{900x256}.
|
||
|
||
The foreground color expressions can use the following variables:
|
||
@table @option
|
||
@item MIN
|
||
Minimal value of metadata value.
|
||
|
||
@item MAX
|
||
Maximal value of metadata value.
|
||
|
||
@item VAL
|
||
Current metadata key value.
|
||
@end table
|
||
|
||
The color is defined as 0xAABBGGRR.
|
||
@end table
|
||
|
||
Example using metadata from @ref{signalstats} filter:
|
||
@example
|
||
signalstats,drawgraph=lavfi.signalstats.YAVG:min=0:max=255
|
||
@end example
|
||
|
||
Example using metadata from @ref{ebur128} filter:
|
||
@example
|
||
ebur128=metadata=1,adrawgraph=lavfi.r128.M:min=-120:max=5
|
||
@end example
|
||
|
||
@anchor{ebur128}
|
||
@section ebur128
|
||
|
||
EBU R128 scanner filter. This filter takes an audio stream as input and outputs
|
||
it unchanged. By default, it logs a message at a frequency of 10Hz with the
|
||
Momentary loudness (identified by @code{M}), Short-term loudness (@code{S}),
|
||
Integrated loudness (@code{I}) and Loudness Range (@code{LRA}).
|
||
|
||
The filter also has a video output (see the @var{video} option) with a real
|
||
time graph to observe the loudness evolution. The graphic contains the logged
|
||
message mentioned above, so it is not printed anymore when this option is set,
|
||
unless the verbose logging is set. The main graphing area contains the
|
||
short-term loudness (3 seconds of analysis), and the gauge on the right is for
|
||
the momentary loudness (400 milliseconds).
|
||
|
||
More information about the Loudness Recommendation EBU R128 on
|
||
@url{http://tech.ebu.ch/loudness}.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
|
||
@item video
|
||
Activate the video output. The audio stream is passed unchanged whether this
|
||
option is set or no. The video stream will be the first output stream if
|
||
activated. Default is @code{0}.
|
||
|
||
@item size
|
||
Set the video size. This option is for video only. For the syntax of this
|
||
option, check the
|
||
@ref{video size syntax,,"Video size" section in the ffmpeg-utils manual,ffmpeg-utils}.
|
||
Default and minimum resolution is @code{640x480}.
|
||
|
||
@item meter
|
||
Set the EBU scale meter. Default is @code{9}. Common values are @code{9} and
|
||
@code{18}, respectively for EBU scale meter +9 and EBU scale meter +18. Any
|
||
other integer value between this range is allowed.
|
||
|
||
@item metadata
|
||
Set metadata injection. If set to @code{1}, the audio input will be segmented
|
||
into 100ms output frames, each of them containing various loudness information
|
||
in metadata. All the metadata keys are prefixed with @code{lavfi.r128.}.
|
||
|
||
Default is @code{0}.
|
||
|
||
@item framelog
|
||
Force the frame logging level.
|
||
|
||
Available values are:
|
||
@table @samp
|
||
@item info
|
||
information logging level
|
||
@item verbose
|
||
verbose logging level
|
||
@end table
|
||
|
||
By default, the logging level is set to @var{info}. If the @option{video} or
|
||
the @option{metadata} options are set, it switches to @var{verbose}.
|
||
|
||
@item peak
|
||
Set peak mode(s).
|
||
|
||
Available modes can be cumulated (the option is a @code{flag} type). Possible
|
||
values are:
|
||
@table @samp
|
||
@item none
|
||
Disable any peak mode (default).
|
||
@item sample
|
||
Enable sample-peak mode.
|
||
|
||
Simple peak mode looking for the higher sample value. It logs a message
|
||
for sample-peak (identified by @code{SPK}).
|
||
@item true
|
||
Enable true-peak mode.
|
||
|
||
If enabled, the peak lookup is done on an over-sampled version of the input
|
||
stream for better peak accuracy. It logs a message for true-peak.
|
||
(identified by @code{TPK}) and true-peak per frame (identified by @code{FTPK}).
|
||
This mode requires a build with @code{libswresample}.
|
||
@end table
|
||
|
||
@item dualmono
|
||
Treat mono input files as "dual mono". If a mono file is intended for playback
|
||
on a stereo system, its EBU R128 measurement will be perceptually incorrect.
|
||
If set to @code{true}, this option will compensate for this effect.
|
||
Multi-channel input files are not affected by this option.
|
||
|
||
@item panlaw
|
||
Set a specific pan law to be used for the measurement of dual mono files.
|
||
This parameter is optional, and has a default value of -3.01dB.
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Real-time graph using @command{ffplay}, with a EBU scale meter +18:
|
||
@example
|
||
ffplay -f lavfi -i "amovie=input.mp3,ebur128=video=1:meter=18 [out0][out1]"
|
||
@end example
|
||
|
||
@item
|
||
Run an analysis with @command{ffmpeg}:
|
||
@example
|
||
ffmpeg -nostats -i input.mp3 -filter_complex ebur128 -f null -
|
||
@end example
|
||
@end itemize
|
||
|
||
@section interleave, ainterleave
|
||
|
||
Temporally interleave frames from several inputs.
|
||
|
||
@code{interleave} works with video inputs, @code{ainterleave} with audio.
|
||
|
||
These filters read frames from several inputs and send the oldest
|
||
queued frame to the output.
|
||
|
||
Input streams must have well defined, monotonically increasing frame
|
||
timestamp values.
|
||
|
||
In order to submit one frame to output, these filters need to enqueue
|
||
at least one frame for each input, so they cannot work in case one
|
||
input is not yet terminated and will not receive incoming frames.
|
||
|
||
For example consider the case when one input is a @code{select} filter
|
||
which always drops input frames. The @code{interleave} filter will keep
|
||
reading from that input, but it will never be able to send new frames
|
||
to output until the input sends an end-of-stream signal.
|
||
|
||
Also, depending on inputs synchronization, the filters will drop
|
||
frames in case one input receives more frames than the other ones, and
|
||
the queue is already filled.
|
||
|
||
These filters accept the following options:
|
||
|
||
@table @option
|
||
@item nb_inputs, n
|
||
Set the number of different inputs, it is 2 by default.
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Interleave frames belonging to different streams using @command{ffmpeg}:
|
||
@example
|
||
ffmpeg -i bambi.avi -i pr0n.mkv -filter_complex "[0:v][1:v] interleave" out.avi
|
||
@end example
|
||
|
||
@item
|
||
Add flickering blur effect:
|
||
@example
|
||
select='if(gt(random(0), 0.2), 1, 2)':n=2 [tmp], boxblur=2:2, [tmp] interleave
|
||
@end example
|
||
@end itemize
|
||
|
||
@section metadata, ametadata
|
||
|
||
Manipulate frame metadata.
|
||
|
||
This filter accepts the following options:
|
||
|
||
@table @option
|
||
@item mode
|
||
Set mode of operation of the filter.
|
||
|
||
Can be one of the following:
|
||
|
||
@table @samp
|
||
@item select
|
||
If both @code{value} and @code{key} is set, select frames
|
||
which have such metadata. If only @code{key} is set, select
|
||
every frame that has such key in metadata.
|
||
|
||
@item add
|
||
Add new metadata @code{key} and @code{value}. If key is already available
|
||
do nothing.
|
||
|
||
@item modify
|
||
Modify value of already present key.
|
||
|
||
@item delete
|
||
If @code{value} is set, delete only keys that have such value.
|
||
Otherwise, delete key. If @code{key} is not set, delete all metadata values in
|
||
the frame.
|
||
|
||
@item print
|
||
Print key and its value if metadata was found. If @code{key} is not set print all
|
||
metadata values available in frame.
|
||
@end table
|
||
|
||
@item key
|
||
Set key used with all modes. Must be set for all modes except @code{print} and @code{delete}.
|
||
|
||
@item value
|
||
Set metadata value which will be used. This option is mandatory for
|
||
@code{modify} and @code{add} mode.
|
||
|
||
@item function
|
||
Which function to use when comparing metadata value and @code{value}.
|
||
|
||
Can be one of following:
|
||
|
||
@table @samp
|
||
@item same_str
|
||
Values are interpreted as strings, returns true if metadata value is same as @code{value}.
|
||
|
||
@item starts_with
|
||
Values are interpreted as strings, returns true if metadata value starts with
|
||
the @code{value} option string.
|
||
|
||
@item less
|
||
Values are interpreted as floats, returns true if metadata value is less than @code{value}.
|
||
|
||
@item equal
|
||
Values are interpreted as floats, returns true if @code{value} is equal with metadata value.
|
||
|
||
@item greater
|
||
Values are interpreted as floats, returns true if metadata value is greater than @code{value}.
|
||
|
||
@item expr
|
||
Values are interpreted as floats, returns true if expression from option @code{expr}
|
||
evaluates to true.
|
||
@end table
|
||
|
||
@item expr
|
||
Set expression which is used when @code{function} is set to @code{expr}.
|
||
The expression is evaluated through the eval API and can contain the following
|
||
constants:
|
||
|
||
@table @option
|
||
@item VALUE1
|
||
Float representation of @code{value} from metadata key.
|
||
|
||
@item VALUE2
|
||
Float representation of @code{value} as supplied by user in @code{value} option.
|
||
@end table
|
||
|
||
@item file
|
||
If specified in @code{print} mode, output is written to the named file. Instead of
|
||
plain filename any writable url can be specified. Filename ``-'' is a shorthand
|
||
for standard output. If @code{file} option is not set, output is written to the log
|
||
with AV_LOG_INFO loglevel.
|
||
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Print all metadata values for frames with key @code{lavfi.singnalstats.YDIF} with values
|
||
between 0 and 1.
|
||
@example
|
||
signalstats,metadata=print:key=lavfi.signalstats.YDIF:value=0:function=expr:expr='between(VALUE1,0,1)'
|
||
@end example
|
||
@item
|
||
Print silencedetect output to file @file{metadata.txt}.
|
||
@example
|
||
silencedetect,ametadata=mode=print:file=metadata.txt
|
||
@end example
|
||
@item
|
||
Direct all metadata to a pipe with file descriptor 4.
|
||
@example
|
||
metadata=mode=print:file='pipe\:4'
|
||
@end example
|
||
@end itemize
|
||
|
||
@section perms, aperms
|
||
|
||
Set read/write permissions for the output frames.
|
||
|
||
These filters are mainly aimed at developers to test direct path in the
|
||
following filter in the filtergraph.
|
||
|
||
The filters accept the following options:
|
||
|
||
@table @option
|
||
@item mode
|
||
Select the permissions mode.
|
||
|
||
It accepts the following values:
|
||
@table @samp
|
||
@item none
|
||
Do nothing. This is the default.
|
||
@item ro
|
||
Set all the output frames read-only.
|
||
@item rw
|
||
Set all the output frames directly writable.
|
||
@item toggle
|
||
Make the frame read-only if writable, and writable if read-only.
|
||
@item random
|
||
Set each output frame read-only or writable randomly.
|
||
@end table
|
||
|
||
@item seed
|
||
Set the seed for the @var{random} mode, must be an integer included between
|
||
@code{0} and @code{UINT32_MAX}. If not specified, or if explicitly set to
|
||
@code{-1}, the filter will try to use a good random seed on a best effort
|
||
basis.
|
||
@end table
|
||
|
||
Note: in case of auto-inserted filter between the permission filter and the
|
||
following one, the permission might not be received as expected in that
|
||
following filter. Inserting a @ref{format} or @ref{aformat} filter before the
|
||
perms/aperms filter can avoid this problem.
|
||
|
||
@section realtime, arealtime
|
||
|
||
Slow down filtering to match real time approximatively.
|
||
|
||
These filters will pause the filtering for a variable amount of time to
|
||
match the output rate with the input timestamps.
|
||
They are similar to the @option{re} option to @code{ffmpeg}.
|
||
|
||
They accept the following options:
|
||
|
||
@table @option
|
||
@item limit
|
||
Time limit for the pauses. Any pause longer than that will be considered
|
||
a timestamp discontinuity and reset the timer. Default is 2 seconds.
|
||
@end table
|
||
|
||
@anchor{select}
|
||
@section select, aselect
|
||
|
||
Select frames to pass in output.
|
||
|
||
This filter accepts the following options:
|
||
|
||
@table @option
|
||
|
||
@item expr, e
|
||
Set expression, which is evaluated for each input frame.
|
||
|
||
If the expression is evaluated to zero, the frame is discarded.
|
||
|
||
If the evaluation result is negative or NaN, the frame is sent to the
|
||
first output; otherwise it is sent to the output with index
|
||
@code{ceil(val)-1}, assuming that the input index starts from 0.
|
||
|
||
For example a value of @code{1.2} corresponds to the output with index
|
||
@code{ceil(1.2)-1 = 2-1 = 1}, that is the second output.
|
||
|
||
@item outputs, n
|
||
Set the number of outputs. The output to which to send the selected
|
||
frame is based on the result of the evaluation. Default value is 1.
|
||
@end table
|
||
|
||
The expression can contain the following constants:
|
||
|
||
@table @option
|
||
@item n
|
||
The (sequential) number of the filtered frame, starting from 0.
|
||
|
||
@item selected_n
|
||
The (sequential) number of the selected frame, starting from 0.
|
||
|
||
@item prev_selected_n
|
||
The sequential number of the last selected frame. It's NAN if undefined.
|
||
|
||
@item TB
|
||
The timebase of the input timestamps.
|
||
|
||
@item pts
|
||
The PTS (Presentation TimeStamp) of the filtered video frame,
|
||
expressed in @var{TB} units. It's NAN if undefined.
|
||
|
||
@item t
|
||
The PTS of the filtered video frame,
|
||
expressed in seconds. It's NAN if undefined.
|
||
|
||
@item prev_pts
|
||
The PTS of the previously filtered video frame. It's NAN if undefined.
|
||
|
||
@item prev_selected_pts
|
||
The PTS of the last previously filtered video frame. It's NAN if undefined.
|
||
|
||
@item prev_selected_t
|
||
The PTS of the last previously selected video frame. It's NAN if undefined.
|
||
|
||
@item start_pts
|
||
The PTS of the first video frame in the video. It's NAN if undefined.
|
||
|
||
@item start_t
|
||
The time of the first video frame in the video. It's NAN if undefined.
|
||
|
||
@item pict_type @emph{(video only)}
|
||
The type of the filtered frame. It can assume one of the following
|
||
values:
|
||
@table @option
|
||
@item I
|
||
@item P
|
||
@item B
|
||
@item S
|
||
@item SI
|
||
@item SP
|
||
@item BI
|
||
@end table
|
||
|
||
@item interlace_type @emph{(video only)}
|
||
The frame interlace type. It can assume one of the following values:
|
||
@table @option
|
||
@item PROGRESSIVE
|
||
The frame is progressive (not interlaced).
|
||
@item TOPFIRST
|
||
The frame is top-field-first.
|
||
@item BOTTOMFIRST
|
||
The frame is bottom-field-first.
|
||
@end table
|
||
|
||
@item consumed_sample_n @emph{(audio only)}
|
||
the number of selected samples before the current frame
|
||
|
||
@item samples_n @emph{(audio only)}
|
||
the number of samples in the current frame
|
||
|
||
@item sample_rate @emph{(audio only)}
|
||
the input sample rate
|
||
|
||
@item key
|
||
This is 1 if the filtered frame is a key-frame, 0 otherwise.
|
||
|
||
@item pos
|
||
the position in the file of the filtered frame, -1 if the information
|
||
is not available (e.g. for synthetic video)
|
||
|
||
@item scene @emph{(video only)}
|
||
value between 0 and 1 to indicate a new scene; a low value reflects a low
|
||
probability for the current frame to introduce a new scene, while a higher
|
||
value means the current frame is more likely to be one (see the example below)
|
||
|
||
@item concatdec_select
|
||
The concat demuxer can select only part of a concat input file by setting an
|
||
inpoint and an outpoint, but the output packets may not be entirely contained
|
||
in the selected interval. By using this variable, it is possible to skip frames
|
||
generated by the concat demuxer which are not exactly contained in the selected
|
||
interval.
|
||
|
||
This works by comparing the frame pts against the @var{lavf.concat.start_time}
|
||
and the @var{lavf.concat.duration} packet metadata values which are also
|
||
present in the decoded frames.
|
||
|
||
The @var{concatdec_select} variable is -1 if the frame pts is at least
|
||
start_time and either the duration metadata is missing or the frame pts is less
|
||
than start_time + duration, 0 otherwise, and NaN if the start_time metadata is
|
||
missing.
|
||
|
||
That basically means that an input frame is selected if its pts is within the
|
||
interval set by the concat demuxer.
|
||
|
||
@end table
|
||
|
||
The default value of the select expression is "1".
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Select all frames in input:
|
||
@example
|
||
select
|
||
@end example
|
||
|
||
The example above is the same as:
|
||
@example
|
||
select=1
|
||
@end example
|
||
|
||
@item
|
||
Skip all frames:
|
||
@example
|
||
select=0
|
||
@end example
|
||
|
||
@item
|
||
Select only I-frames:
|
||
@example
|
||
select='eq(pict_type\,I)'
|
||
@end example
|
||
|
||
@item
|
||
Select one frame every 100:
|
||
@example
|
||
select='not(mod(n\,100))'
|
||
@end example
|
||
|
||
@item
|
||
Select only frames contained in the 10-20 time interval:
|
||
@example
|
||
select=between(t\,10\,20)
|
||
@end example
|
||
|
||
@item
|
||
Select only I-frames contained in the 10-20 time interval:
|
||
@example
|
||
select=between(t\,10\,20)*eq(pict_type\,I)
|
||
@end example
|
||
|
||
@item
|
||
Select frames with a minimum distance of 10 seconds:
|
||
@example
|
||
select='isnan(prev_selected_t)+gte(t-prev_selected_t\,10)'
|
||
@end example
|
||
|
||
@item
|
||
Use aselect to select only audio frames with samples number > 100:
|
||
@example
|
||
aselect='gt(samples_n\,100)'
|
||
@end example
|
||
|
||
@item
|
||
Create a mosaic of the first scenes:
|
||
@example
|
||
ffmpeg -i video.avi -vf select='gt(scene\,0.4)',scale=160:120,tile -frames:v 1 preview.png
|
||
@end example
|
||
|
||
Comparing @var{scene} against a value between 0.3 and 0.5 is generally a sane
|
||
choice.
|
||
|
||
@item
|
||
Send even and odd frames to separate outputs, and compose them:
|
||
@example
|
||
select=n=2:e='mod(n, 2)+1' [odd][even]; [odd] pad=h=2*ih [tmp]; [tmp][even] overlay=y=h
|
||
@end example
|
||
|
||
@item
|
||
Select useful frames from an ffconcat file which is using inpoints and
|
||
outpoints but where the source files are not intra frame only.
|
||
@example
|
||
ffmpeg -copyts -vsync 0 -segment_time_metadata 1 -i input.ffconcat -vf select=concatdec_select -af aselect=concatdec_select output.avi
|
||
@end example
|
||
@end itemize
|
||
|
||
@section sendcmd, asendcmd
|
||
|
||
Send commands to filters in the filtergraph.
|
||
|
||
These filters read commands to be sent to other filters in the
|
||
filtergraph.
|
||
|
||
@code{sendcmd} must be inserted between two video filters,
|
||
@code{asendcmd} must be inserted between two audio filters, but apart
|
||
from that they act the same way.
|
||
|
||
The specification of commands can be provided in the filter arguments
|
||
with the @var{commands} option, or in a file specified by the
|
||
@var{filename} option.
|
||
|
||
These filters accept the following options:
|
||
@table @option
|
||
@item commands, c
|
||
Set the commands to be read and sent to the other filters.
|
||
@item filename, f
|
||
Set the filename of the commands to be read and sent to the other
|
||
filters.
|
||
@end table
|
||
|
||
@subsection Commands syntax
|
||
|
||
A commands description consists of a sequence of interval
|
||
specifications, comprising a list of commands to be executed when a
|
||
particular event related to that interval occurs. The occurring event
|
||
is typically the current frame time entering or leaving a given time
|
||
interval.
|
||
|
||
An interval is specified by the following syntax:
|
||
@example
|
||
@var{START}[-@var{END}] @var{COMMANDS};
|
||
@end example
|
||
|
||
The time interval is specified by the @var{START} and @var{END} times.
|
||
@var{END} is optional and defaults to the maximum time.
|
||
|
||
The current frame time is considered within the specified interval if
|
||
it is included in the interval [@var{START}, @var{END}), that is when
|
||
the time is greater or equal to @var{START} and is lesser than
|
||
@var{END}.
|
||
|
||
@var{COMMANDS} consists of a sequence of one or more command
|
||
specifications, separated by ",", relating to that interval. The
|
||
syntax of a command specification is given by:
|
||
@example
|
||
[@var{FLAGS}] @var{TARGET} @var{COMMAND} @var{ARG}
|
||
@end example
|
||
|
||
@var{FLAGS} is optional and specifies the type of events relating to
|
||
the time interval which enable sending the specified command, and must
|
||
be a non-null sequence of identifier flags separated by "+" or "|" and
|
||
enclosed between "[" and "]".
|
||
|
||
The following flags are recognized:
|
||
@table @option
|
||
@item enter
|
||
The command is sent when the current frame timestamp enters the
|
||
specified interval. In other words, the command is sent when the
|
||
previous frame timestamp was not in the given interval, and the
|
||
current is.
|
||
|
||
@item leave
|
||
The command is sent when the current frame timestamp leaves the
|
||
specified interval. In other words, the command is sent when the
|
||
previous frame timestamp was in the given interval, and the
|
||
current is not.
|
||
@end table
|
||
|
||
If @var{FLAGS} is not specified, a default value of @code{[enter]} is
|
||
assumed.
|
||
|
||
@var{TARGET} specifies the target of the command, usually the name of
|
||
the filter class or a specific filter instance name.
|
||
|
||
@var{COMMAND} specifies the name of the command for the target filter.
|
||
|
||
@var{ARG} is optional and specifies the optional list of argument for
|
||
the given @var{COMMAND}.
|
||
|
||
Between one interval specification and another, whitespaces, or
|
||
sequences of characters starting with @code{#} until the end of line,
|
||
are ignored and can be used to annotate comments.
|
||
|
||
A simplified BNF description of the commands specification syntax
|
||
follows:
|
||
@example
|
||
@var{COMMAND_FLAG} ::= "enter" | "leave"
|
||
@var{COMMAND_FLAGS} ::= @var{COMMAND_FLAG} [(+|"|")@var{COMMAND_FLAG}]
|
||
@var{COMMAND} ::= ["[" @var{COMMAND_FLAGS} "]"] @var{TARGET} @var{COMMAND} [@var{ARG}]
|
||
@var{COMMANDS} ::= @var{COMMAND} [,@var{COMMANDS}]
|
||
@var{INTERVAL} ::= @var{START}[-@var{END}] @var{COMMANDS}
|
||
@var{INTERVALS} ::= @var{INTERVAL}[;@var{INTERVALS}]
|
||
@end example
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Specify audio tempo change at second 4:
|
||
@example
|
||
asendcmd=c='4.0 atempo tempo 1.5',atempo
|
||
@end example
|
||
|
||
@item
|
||
Target a specific filter instance:
|
||
@example
|
||
asendcmd=c='4.0 atempo@@my tempo 1.5',atempo@@my
|
||
@end example
|
||
|
||
@item
|
||
Specify a list of drawtext and hue commands in a file.
|
||
@example
|
||
# show text in the interval 5-10
|
||
5.0-10.0 [enter] drawtext reinit 'fontfile=FreeSerif.ttf:text=hello world',
|
||
[leave] drawtext reinit 'fontfile=FreeSerif.ttf:text=';
|
||
|
||
# desaturate the image in the interval 15-20
|
||
15.0-20.0 [enter] hue s 0,
|
||
[enter] drawtext reinit 'fontfile=FreeSerif.ttf:text=nocolor',
|
||
[leave] hue s 1,
|
||
[leave] drawtext reinit 'fontfile=FreeSerif.ttf:text=color';
|
||
|
||
# apply an exponential saturation fade-out effect, starting from time 25
|
||
25 [enter] hue s exp(25-t)
|
||
@end example
|
||
|
||
A filtergraph allowing to read and process the above command list
|
||
stored in a file @file{test.cmd}, can be specified with:
|
||
@example
|
||
sendcmd=f=test.cmd,drawtext=fontfile=FreeSerif.ttf:text='',hue
|
||
@end example
|
||
@end itemize
|
||
|
||
@anchor{setpts}
|
||
@section setpts, asetpts
|
||
|
||
Change the PTS (presentation timestamp) of the input frames.
|
||
|
||
@code{setpts} works on video frames, @code{asetpts} on audio frames.
|
||
|
||
This filter accepts the following options:
|
||
|
||
@table @option
|
||
|
||
@item expr
|
||
The expression which is evaluated for each frame to construct its timestamp.
|
||
|
||
@end table
|
||
|
||
The expression is evaluated through the eval API and can contain the following
|
||
constants:
|
||
|
||
@table @option
|
||
@item FRAME_RATE
|
||
frame rate, only defined for constant frame-rate video
|
||
|
||
@item PTS
|
||
The presentation timestamp in input
|
||
|
||
@item N
|
||
The count of the input frame for video or the number of consumed samples,
|
||
not including the current frame for audio, starting from 0.
|
||
|
||
@item NB_CONSUMED_SAMPLES
|
||
The number of consumed samples, not including the current frame (only
|
||
audio)
|
||
|
||
@item NB_SAMPLES, S
|
||
The number of samples in the current frame (only audio)
|
||
|
||
@item SAMPLE_RATE, SR
|
||
The audio sample rate.
|
||
|
||
@item STARTPTS
|
||
The PTS of the first frame.
|
||
|
||
@item STARTT
|
||
the time in seconds of the first frame
|
||
|
||
@item INTERLACED
|
||
State whether the current frame is interlaced.
|
||
|
||
@item T
|
||
the time in seconds of the current frame
|
||
|
||
@item POS
|
||
original position in the file of the frame, or undefined if undefined
|
||
for the current frame
|
||
|
||
@item PREV_INPTS
|
||
The previous input PTS.
|
||
|
||
@item PREV_INT
|
||
previous input time in seconds
|
||
|
||
@item PREV_OUTPTS
|
||
The previous output PTS.
|
||
|
||
@item PREV_OUTT
|
||
previous output time in seconds
|
||
|
||
@item RTCTIME
|
||
The wallclock (RTC) time in microseconds. This is deprecated, use time(0)
|
||
instead.
|
||
|
||
@item RTCSTART
|
||
The wallclock (RTC) time at the start of the movie in microseconds.
|
||
|
||
@item TB
|
||
The timebase of the input timestamps.
|
||
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Start counting PTS from zero
|
||
@example
|
||
setpts=PTS-STARTPTS
|
||
@end example
|
||
|
||
@item
|
||
Apply fast motion effect:
|
||
@example
|
||
setpts=0.5*PTS
|
||
@end example
|
||
|
||
@item
|
||
Apply slow motion effect:
|
||
@example
|
||
setpts=2.0*PTS
|
||
@end example
|
||
|
||
@item
|
||
Set fixed rate of 25 frames per second:
|
||
@example
|
||
setpts=N/(25*TB)
|
||
@end example
|
||
|
||
@item
|
||
Set fixed rate 25 fps with some jitter:
|
||
@example
|
||
setpts='1/(25*TB) * (N + 0.05 * sin(N*2*PI/25))'
|
||
@end example
|
||
|
||
@item
|
||
Apply an offset of 10 seconds to the input PTS:
|
||
@example
|
||
setpts=PTS+10/TB
|
||
@end example
|
||
|
||
@item
|
||
Generate timestamps from a "live source" and rebase onto the current timebase:
|
||
@example
|
||
setpts='(RTCTIME - RTCSTART) / (TB * 1000000)'
|
||
@end example
|
||
|
||
@item
|
||
Generate timestamps by counting samples:
|
||
@example
|
||
asetpts=N/SR/TB
|
||
@end example
|
||
|
||
@end itemize
|
||
|
||
@section settb, asettb
|
||
|
||
Set the timebase to use for the output frames timestamps.
|
||
It is mainly useful for testing timebase configuration.
|
||
|
||
It accepts the following parameters:
|
||
|
||
@table @option
|
||
|
||
@item expr, tb
|
||
The expression which is evaluated into the output timebase.
|
||
|
||
@end table
|
||
|
||
The value for @option{tb} is an arithmetic expression representing a
|
||
rational. The expression can contain the constants "AVTB" (the default
|
||
timebase), "intb" (the input timebase) and "sr" (the sample rate,
|
||
audio only). Default value is "intb".
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Set the timebase to 1/25:
|
||
@example
|
||
settb=expr=1/25
|
||
@end example
|
||
|
||
@item
|
||
Set the timebase to 1/10:
|
||
@example
|
||
settb=expr=0.1
|
||
@end example
|
||
|
||
@item
|
||
Set the timebase to 1001/1000:
|
||
@example
|
||
settb=1+0.001
|
||
@end example
|
||
|
||
@item
|
||
Set the timebase to 2*intb:
|
||
@example
|
||
settb=2*intb
|
||
@end example
|
||
|
||
@item
|
||
Set the default timebase value:
|
||
@example
|
||
settb=AVTB
|
||
@end example
|
||
@end itemize
|
||
|
||
@section showcqt
|
||
Convert input audio to a video output representing frequency spectrum
|
||
logarithmically using Brown-Puckette constant Q transform algorithm with
|
||
direct frequency domain coefficient calculation (but the transform itself
|
||
is not really constant Q, instead the Q factor is actually variable/clamped),
|
||
with musical tone scale, from E0 to D#10.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item size, s
|
||
Specify the video size for the output. It must be even. For the syntax of this option,
|
||
check the @ref{video size syntax,,"Video size" section in the ffmpeg-utils manual,ffmpeg-utils}.
|
||
Default value is @code{1920x1080}.
|
||
|
||
@item fps, rate, r
|
||
Set the output frame rate. Default value is @code{25}.
|
||
|
||
@item bar_h
|
||
Set the bargraph height. It must be even. Default value is @code{-1} which
|
||
computes the bargraph height automatically.
|
||
|
||
@item axis_h
|
||
Set the axis height. It must be even. Default value is @code{-1} which computes
|
||
the axis height automatically.
|
||
|
||
@item sono_h
|
||
Set the sonogram height. It must be even. Default value is @code{-1} which
|
||
computes the sonogram height automatically.
|
||
|
||
@item fullhd
|
||
Set the fullhd resolution. This option is deprecated, use @var{size}, @var{s}
|
||
instead. Default value is @code{1}.
|
||
|
||
@item sono_v, volume
|
||
Specify the sonogram volume expression. It can contain variables:
|
||
@table @option
|
||
@item bar_v
|
||
the @var{bar_v} evaluated expression
|
||
@item frequency, freq, f
|
||
the frequency where it is evaluated
|
||
@item timeclamp, tc
|
||
the value of @var{timeclamp} option
|
||
@end table
|
||
and functions:
|
||
@table @option
|
||
@item a_weighting(f)
|
||
A-weighting of equal loudness
|
||
@item b_weighting(f)
|
||
B-weighting of equal loudness
|
||
@item c_weighting(f)
|
||
C-weighting of equal loudness.
|
||
@end table
|
||
Default value is @code{16}.
|
||
|
||
@item bar_v, volume2
|
||
Specify the bargraph volume expression. It can contain variables:
|
||
@table @option
|
||
@item sono_v
|
||
the @var{sono_v} evaluated expression
|
||
@item frequency, freq, f
|
||
the frequency where it is evaluated
|
||
@item timeclamp, tc
|
||
the value of @var{timeclamp} option
|
||
@end table
|
||
and functions:
|
||
@table @option
|
||
@item a_weighting(f)
|
||
A-weighting of equal loudness
|
||
@item b_weighting(f)
|
||
B-weighting of equal loudness
|
||
@item c_weighting(f)
|
||
C-weighting of equal loudness.
|
||
@end table
|
||
Default value is @code{sono_v}.
|
||
|
||
@item sono_g, gamma
|
||
Specify the sonogram gamma. Lower gamma makes the spectrum more contrast,
|
||
higher gamma makes the spectrum having more range. Default value is @code{3}.
|
||
Acceptable range is @code{[1, 7]}.
|
||
|
||
@item bar_g, gamma2
|
||
Specify the bargraph gamma. Default value is @code{1}. Acceptable range is
|
||
@code{[1, 7]}.
|
||
|
||
@item bar_t
|
||
Specify the bargraph transparency level. Lower value makes the bargraph sharper.
|
||
Default value is @code{1}. Acceptable range is @code{[0, 1]}.
|
||
|
||
@item timeclamp, tc
|
||
Specify the transform timeclamp. At low frequency, there is trade-off between
|
||
accuracy in time domain and frequency domain. If timeclamp is lower,
|
||
event in time domain is represented more accurately (such as fast bass drum),
|
||
otherwise event in frequency domain is represented more accurately
|
||
(such as bass guitar). Acceptable range is @code{[0.002, 1]}. Default value is @code{0.17}.
|
||
|
||
@item attack
|
||
Set attack time in seconds. The default is @code{0} (disabled). Otherwise, it
|
||
limits future samples by applying asymmetric windowing in time domain, useful
|
||
when low latency is required. Accepted range is @code{[0, 1]}.
|
||
|
||
@item basefreq
|
||
Specify the transform base frequency. Default value is @code{20.01523126408007475},
|
||
which is frequency 50 cents below E0. Acceptable range is @code{[10, 100000]}.
|
||
|
||
@item endfreq
|
||
Specify the transform end frequency. Default value is @code{20495.59681441799654},
|
||
which is frequency 50 cents above D#10. Acceptable range is @code{[10, 100000]}.
|
||
|
||
@item coeffclamp
|
||
This option is deprecated and ignored.
|
||
|
||
@item tlength
|
||
Specify the transform length in time domain. Use this option to control accuracy
|
||
trade-off between time domain and frequency domain at every frequency sample.
|
||
It can contain variables:
|
||
@table @option
|
||
@item frequency, freq, f
|
||
the frequency where it is evaluated
|
||
@item timeclamp, tc
|
||
the value of @var{timeclamp} option.
|
||
@end table
|
||
Default value is @code{384*tc/(384+tc*f)}.
|
||
|
||
@item count
|
||
Specify the transform count for every video frame. Default value is @code{6}.
|
||
Acceptable range is @code{[1, 30]}.
|
||
|
||
@item fcount
|
||
Specify the transform count for every single pixel. Default value is @code{0},
|
||
which makes it computed automatically. Acceptable range is @code{[0, 10]}.
|
||
|
||
@item fontfile
|
||
Specify font file for use with freetype to draw the axis. If not specified,
|
||
use embedded font. Note that drawing with font file or embedded font is not
|
||
implemented with custom @var{basefreq} and @var{endfreq}, use @var{axisfile}
|
||
option instead.
|
||
|
||
@item font
|
||
Specify fontconfig pattern. This has lower priority than @var{fontfile}.
|
||
The : in the pattern may be replaced by | to avoid unnecessary escaping.
|
||
|
||
@item fontcolor
|
||
Specify font color expression. This is arithmetic expression that should return
|
||
integer value 0xRRGGBB. It can contain variables:
|
||
@table @option
|
||
@item frequency, freq, f
|
||
the frequency where it is evaluated
|
||
@item timeclamp, tc
|
||
the value of @var{timeclamp} option
|
||
@end table
|
||
and functions:
|
||
@table @option
|
||
@item midi(f)
|
||
midi number of frequency f, some midi numbers: E0(16), C1(24), C2(36), A4(69)
|
||
@item r(x), g(x), b(x)
|
||
red, green, and blue value of intensity x.
|
||
@end table
|
||
Default value is @code{st(0, (midi(f)-59.5)/12);
|
||
st(1, if(between(ld(0),0,1), 0.5-0.5*cos(2*PI*ld(0)), 0));
|
||
r(1-ld(1)) + b(ld(1))}.
|
||
|
||
@item axisfile
|
||
Specify image file to draw the axis. This option override @var{fontfile} and
|
||
@var{fontcolor} option.
|
||
|
||
@item axis, text
|
||
Enable/disable drawing text to the axis. If it is set to @code{0}, drawing to
|
||
the axis is disabled, ignoring @var{fontfile} and @var{axisfile} option.
|
||
Default value is @code{1}.
|
||
|
||
@item csp
|
||
Set colorspace. The accepted values are:
|
||
@table @samp
|
||
@item unspecified
|
||
Unspecified (default)
|
||
|
||
@item bt709
|
||
BT.709
|
||
|
||
@item fcc
|
||
FCC
|
||
|
||
@item bt470bg
|
||
BT.470BG or BT.601-6 625
|
||
|
||
@item smpte170m
|
||
SMPTE-170M or BT.601-6 525
|
||
|
||
@item smpte240m
|
||
SMPTE-240M
|
||
|
||
@item bt2020ncl
|
||
BT.2020 with non-constant luminance
|
||
|
||
@end table
|
||
|
||
@item cscheme
|
||
Set spectrogram color scheme. This is list of floating point values with format
|
||
@code{left_r|left_g|left_b|right_r|right_g|right_b}.
|
||
The default is @code{1|0.5|0|0|0.5|1}.
|
||
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Playing audio while showing the spectrum:
|
||
@example
|
||
ffplay -f lavfi 'amovie=a.mp3, asplit [a][out1]; [a] showcqt [out0]'
|
||
@end example
|
||
|
||
@item
|
||
Same as above, but with frame rate 30 fps:
|
||
@example
|
||
ffplay -f lavfi 'amovie=a.mp3, asplit [a][out1]; [a] showcqt=fps=30:count=5 [out0]'
|
||
@end example
|
||
|
||
@item
|
||
Playing at 1280x720:
|
||
@example
|
||
ffplay -f lavfi 'amovie=a.mp3, asplit [a][out1]; [a] showcqt=s=1280x720:count=4 [out0]'
|
||
@end example
|
||
|
||
@item
|
||
Disable sonogram display:
|
||
@example
|
||
sono_h=0
|
||
@end example
|
||
|
||
@item
|
||
A1 and its harmonics: A1, A2, (near)E3, A3:
|
||
@example
|
||
ffplay -f lavfi 'aevalsrc=0.1*sin(2*PI*55*t)+0.1*sin(4*PI*55*t)+0.1*sin(6*PI*55*t)+0.1*sin(8*PI*55*t),
|
||
asplit[a][out1]; [a] showcqt [out0]'
|
||
@end example
|
||
|
||
@item
|
||
Same as above, but with more accuracy in frequency domain:
|
||
@example
|
||
ffplay -f lavfi 'aevalsrc=0.1*sin(2*PI*55*t)+0.1*sin(4*PI*55*t)+0.1*sin(6*PI*55*t)+0.1*sin(8*PI*55*t),
|
||
asplit[a][out1]; [a] showcqt=timeclamp=0.5 [out0]'
|
||
@end example
|
||
|
||
@item
|
||
Custom volume:
|
||
@example
|
||
bar_v=10:sono_v=bar_v*a_weighting(f)
|
||
@end example
|
||
|
||
@item
|
||
Custom gamma, now spectrum is linear to the amplitude.
|
||
@example
|
||
bar_g=2:sono_g=2
|
||
@end example
|
||
|
||
@item
|
||
Custom tlength equation:
|
||
@example
|
||
tc=0.33:tlength='st(0,0.17); 384*tc / (384 / ld(0) + tc*f /(1-ld(0))) + 384*tc / (tc*f / ld(0) + 384 /(1-ld(0)))'
|
||
@end example
|
||
|
||
@item
|
||
Custom fontcolor and fontfile, C-note is colored green, others are colored blue:
|
||
@example
|
||
fontcolor='if(mod(floor(midi(f)+0.5),12), 0x0000FF, g(1))':fontfile=myfont.ttf
|
||
@end example
|
||
|
||
@item
|
||
Custom font using fontconfig:
|
||
@example
|
||
font='Courier New,Monospace,mono|bold'
|
||
@end example
|
||
|
||
@item
|
||
Custom frequency range with custom axis using image file:
|
||
@example
|
||
axisfile=myaxis.png:basefreq=40:endfreq=10000
|
||
@end example
|
||
@end itemize
|
||
|
||
@section showfreqs
|
||
|
||
Convert input audio to video output representing the audio power spectrum.
|
||
Audio amplitude is on Y-axis while frequency is on X-axis.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item size, s
|
||
Specify size of video. For the syntax of this option, check the
|
||
@ref{video size syntax,,"Video size" section in the ffmpeg-utils manual,ffmpeg-utils}.
|
||
Default is @code{1024x512}.
|
||
|
||
@item mode
|
||
Set display mode.
|
||
This set how each frequency bin will be represented.
|
||
|
||
It accepts the following values:
|
||
@table @samp
|
||
@item line
|
||
@item bar
|
||
@item dot
|
||
@end table
|
||
Default is @code{bar}.
|
||
|
||
@item ascale
|
||
Set amplitude scale.
|
||
|
||
It accepts the following values:
|
||
@table @samp
|
||
@item lin
|
||
Linear scale.
|
||
|
||
@item sqrt
|
||
Square root scale.
|
||
|
||
@item cbrt
|
||
Cubic root scale.
|
||
|
||
@item log
|
||
Logarithmic scale.
|
||
@end table
|
||
Default is @code{log}.
|
||
|
||
@item fscale
|
||
Set frequency scale.
|
||
|
||
It accepts the following values:
|
||
@table @samp
|
||
@item lin
|
||
Linear scale.
|
||
|
||
@item log
|
||
Logarithmic scale.
|
||
|
||
@item rlog
|
||
Reverse logarithmic scale.
|
||
@end table
|
||
Default is @code{lin}.
|
||
|
||
@item win_size
|
||
Set window size.
|
||
|
||
It accepts the following values:
|
||
@table @samp
|
||
@item w16
|
||
@item w32
|
||
@item w64
|
||
@item w128
|
||
@item w256
|
||
@item w512
|
||
@item w1024
|
||
@item w2048
|
||
@item w4096
|
||
@item w8192
|
||
@item w16384
|
||
@item w32768
|
||
@item w65536
|
||
@end table
|
||
Default is @code{w2048}
|
||
|
||
@item win_func
|
||
Set windowing function.
|
||
|
||
It accepts the following values:
|
||
@table @samp
|
||
@item rect
|
||
@item bartlett
|
||
@item hanning
|
||
@item hamming
|
||
@item blackman
|
||
@item welch
|
||
@item flattop
|
||
@item bharris
|
||
@item bnuttall
|
||
@item bhann
|
||
@item sine
|
||
@item nuttall
|
||
@item lanczos
|
||
@item gauss
|
||
@item tukey
|
||
@item dolph
|
||
@item cauchy
|
||
@item parzen
|
||
@item poisson
|
||
@end table
|
||
Default is @code{hanning}.
|
||
|
||
@item overlap
|
||
Set window overlap. In range @code{[0, 1]}. Default is @code{1},
|
||
which means optimal overlap for selected window function will be picked.
|
||
|
||
@item averaging
|
||
Set time averaging. Setting this to 0 will display current maximal peaks.
|
||
Default is @code{1}, which means time averaging is disabled.
|
||
|
||
@item colors
|
||
Specify list of colors separated by space or by '|' which will be used to
|
||
draw channel frequencies. Unrecognized or missing colors will be replaced
|
||
by white color.
|
||
|
||
@item cmode
|
||
Set channel display mode.
|
||
|
||
It accepts the following values:
|
||
@table @samp
|
||
@item combined
|
||
@item separate
|
||
@end table
|
||
Default is @code{combined}.
|
||
|
||
@item minamp
|
||
Set minimum amplitude used in @code{log} amplitude scaler.
|
||
|
||
@end table
|
||
|
||
@anchor{showspectrum}
|
||
@section showspectrum
|
||
|
||
Convert input audio to a video output, representing the audio frequency
|
||
spectrum.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item size, s
|
||
Specify the video size for the output. For the syntax of this option, check the
|
||
@ref{video size syntax,,"Video size" section in the ffmpeg-utils manual,ffmpeg-utils}.
|
||
Default value is @code{640x512}.
|
||
|
||
@item slide
|
||
Specify how the spectrum should slide along the window.
|
||
|
||
It accepts the following values:
|
||
@table @samp
|
||
@item replace
|
||
the samples start again on the left when they reach the right
|
||
@item scroll
|
||
the samples scroll from right to left
|
||
@item fullframe
|
||
frames are only produced when the samples reach the right
|
||
@item rscroll
|
||
the samples scroll from left to right
|
||
@end table
|
||
|
||
Default value is @code{replace}.
|
||
|
||
@item mode
|
||
Specify display mode.
|
||
|
||
It accepts the following values:
|
||
@table @samp
|
||
@item combined
|
||
all channels are displayed in the same row
|
||
@item separate
|
||
all channels are displayed in separate rows
|
||
@end table
|
||
|
||
Default value is @samp{combined}.
|
||
|
||
@item color
|
||
Specify display color mode.
|
||
|
||
It accepts the following values:
|
||
@table @samp
|
||
@item channel
|
||
each channel is displayed in a separate color
|
||
@item intensity
|
||
each channel is displayed using the same color scheme
|
||
@item rainbow
|
||
each channel is displayed using the rainbow color scheme
|
||
@item moreland
|
||
each channel is displayed using the moreland color scheme
|
||
@item nebulae
|
||
each channel is displayed using the nebulae color scheme
|
||
@item fire
|
||
each channel is displayed using the fire color scheme
|
||
@item fiery
|
||
each channel is displayed using the fiery color scheme
|
||
@item fruit
|
||
each channel is displayed using the fruit color scheme
|
||
@item cool
|
||
each channel is displayed using the cool color scheme
|
||
@end table
|
||
|
||
Default value is @samp{channel}.
|
||
|
||
@item scale
|
||
Specify scale used for calculating intensity color values.
|
||
|
||
It accepts the following values:
|
||
@table @samp
|
||
@item lin
|
||
linear
|
||
@item sqrt
|
||
square root, default
|
||
@item cbrt
|
||
cubic root
|
||
@item log
|
||
logarithmic
|
||
@item 4thrt
|
||
4th root
|
||
@item 5thrt
|
||
5th root
|
||
@end table
|
||
|
||
Default value is @samp{sqrt}.
|
||
|
||
@item saturation
|
||
Set saturation modifier for displayed colors. Negative values provide
|
||
alternative color scheme. @code{0} is no saturation at all.
|
||
Saturation must be in [-10.0, 10.0] range.
|
||
Default value is @code{1}.
|
||
|
||
@item win_func
|
||
Set window function.
|
||
|
||
It accepts the following values:
|
||
@table @samp
|
||
@item rect
|
||
@item bartlett
|
||
@item hann
|
||
@item hanning
|
||
@item hamming
|
||
@item blackman
|
||
@item welch
|
||
@item flattop
|
||
@item bharris
|
||
@item bnuttall
|
||
@item bhann
|
||
@item sine
|
||
@item nuttall
|
||
@item lanczos
|
||
@item gauss
|
||
@item tukey
|
||
@item dolph
|
||
@item cauchy
|
||
@item parzen
|
||
@item poisson
|
||
@end table
|
||
|
||
Default value is @code{hann}.
|
||
|
||
@item orientation
|
||
Set orientation of time vs frequency axis. Can be @code{vertical} or
|
||
@code{horizontal}. Default is @code{vertical}.
|
||
|
||
@item overlap
|
||
Set ratio of overlap window. Default value is @code{0}.
|
||
When value is @code{1} overlap is set to recommended size for specific
|
||
window function currently used.
|
||
|
||
@item gain
|
||
Set scale gain for calculating intensity color values.
|
||
Default value is @code{1}.
|
||
|
||
@item data
|
||
Set which data to display. Can be @code{magnitude}, default or @code{phase}.
|
||
|
||
@item rotation
|
||
Set color rotation, must be in [-1.0, 1.0] range.
|
||
Default value is @code{0}.
|
||
@end table
|
||
|
||
The usage is very similar to the showwaves filter; see the examples in that
|
||
section.
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Large window with logarithmic color scaling:
|
||
@example
|
||
showspectrum=s=1280x480:scale=log
|
||
@end example
|
||
|
||
@item
|
||
Complete example for a colored and sliding spectrum per channel using @command{ffplay}:
|
||
@example
|
||
ffplay -f lavfi 'amovie=input.mp3, asplit [a][out1];
|
||
[a] showspectrum=mode=separate:color=intensity:slide=1:scale=cbrt [out0]'
|
||
@end example
|
||
@end itemize
|
||
|
||
@section showspectrumpic
|
||
|
||
Convert input audio to a single video frame, representing the audio frequency
|
||
spectrum.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item size, s
|
||
Specify the video size for the output. For the syntax of this option, check the
|
||
@ref{video size syntax,,"Video size" section in the ffmpeg-utils manual,ffmpeg-utils}.
|
||
Default value is @code{4096x2048}.
|
||
|
||
@item mode
|
||
Specify display mode.
|
||
|
||
It accepts the following values:
|
||
@table @samp
|
||
@item combined
|
||
all channels are displayed in the same row
|
||
@item separate
|
||
all channels are displayed in separate rows
|
||
@end table
|
||
Default value is @samp{combined}.
|
||
|
||
@item color
|
||
Specify display color mode.
|
||
|
||
It accepts the following values:
|
||
@table @samp
|
||
@item channel
|
||
each channel is displayed in a separate color
|
||
@item intensity
|
||
each channel is displayed using the same color scheme
|
||
@item rainbow
|
||
each channel is displayed using the rainbow color scheme
|
||
@item moreland
|
||
each channel is displayed using the moreland color scheme
|
||
@item nebulae
|
||
each channel is displayed using the nebulae color scheme
|
||
@item fire
|
||
each channel is displayed using the fire color scheme
|
||
@item fiery
|
||
each channel is displayed using the fiery color scheme
|
||
@item fruit
|
||
each channel is displayed using the fruit color scheme
|
||
@item cool
|
||
each channel is displayed using the cool color scheme
|
||
@end table
|
||
Default value is @samp{intensity}.
|
||
|
||
@item scale
|
||
Specify scale used for calculating intensity color values.
|
||
|
||
It accepts the following values:
|
||
@table @samp
|
||
@item lin
|
||
linear
|
||
@item sqrt
|
||
square root, default
|
||
@item cbrt
|
||
cubic root
|
||
@item log
|
||
logarithmic
|
||
@item 4thrt
|
||
4th root
|
||
@item 5thrt
|
||
5th root
|
||
@end table
|
||
Default value is @samp{log}.
|
||
|
||
@item saturation
|
||
Set saturation modifier for displayed colors. Negative values provide
|
||
alternative color scheme. @code{0} is no saturation at all.
|
||
Saturation must be in [-10.0, 10.0] range.
|
||
Default value is @code{1}.
|
||
|
||
@item win_func
|
||
Set window function.
|
||
|
||
It accepts the following values:
|
||
@table @samp
|
||
@item rect
|
||
@item bartlett
|
||
@item hann
|
||
@item hanning
|
||
@item hamming
|
||
@item blackman
|
||
@item welch
|
||
@item flattop
|
||
@item bharris
|
||
@item bnuttall
|
||
@item bhann
|
||
@item sine
|
||
@item nuttall
|
||
@item lanczos
|
||
@item gauss
|
||
@item tukey
|
||
@item dolph
|
||
@item cauchy
|
||
@item parzen
|
||
@item poisson
|
||
@end table
|
||
Default value is @code{hann}.
|
||
|
||
@item orientation
|
||
Set orientation of time vs frequency axis. Can be @code{vertical} or
|
||
@code{horizontal}. Default is @code{vertical}.
|
||
|
||
@item gain
|
||
Set scale gain for calculating intensity color values.
|
||
Default value is @code{1}.
|
||
|
||
@item legend
|
||
Draw time and frequency axes and legends. Default is enabled.
|
||
|
||
@item rotation
|
||
Set color rotation, must be in [-1.0, 1.0] range.
|
||
Default value is @code{0}.
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Extract an audio spectrogram of a whole audio track
|
||
in a 1024x1024 picture using @command{ffmpeg}:
|
||
@example
|
||
ffmpeg -i audio.flac -lavfi showspectrumpic=s=1024x1024 spectrogram.png
|
||
@end example
|
||
@end itemize
|
||
|
||
@section showvolume
|
||
|
||
Convert input audio volume to a video output.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item rate, r
|
||
Set video rate.
|
||
|
||
@item b
|
||
Set border width, allowed range is [0, 5]. Default is 1.
|
||
|
||
@item w
|
||
Set channel width, allowed range is [80, 8192]. Default is 400.
|
||
|
||
@item h
|
||
Set channel height, allowed range is [1, 900]. Default is 20.
|
||
|
||
@item f
|
||
Set fade, allowed range is [0.001, 1]. Default is 0.95.
|
||
|
||
@item c
|
||
Set volume color expression.
|
||
|
||
The expression can use the following variables:
|
||
|
||
@table @option
|
||
@item VOLUME
|
||
Current max volume of channel in dB.
|
||
|
||
@item PEAK
|
||
Current peak.
|
||
|
||
@item CHANNEL
|
||
Current channel number, starting from 0.
|
||
@end table
|
||
|
||
@item t
|
||
If set, displays channel names. Default is enabled.
|
||
|
||
@item v
|
||
If set, displays volume values. Default is enabled.
|
||
|
||
@item o
|
||
Set orientation, can be @code{horizontal} or @code{vertical},
|
||
default is @code{horizontal}.
|
||
|
||
@item s
|
||
Set step size, allowed range s [0, 5]. Default is 0, which means
|
||
step is disabled.
|
||
@end table
|
||
|
||
@section showwaves
|
||
|
||
Convert input audio to a video output, representing the samples waves.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item size, s
|
||
Specify the video size for the output. For the syntax of this option, check the
|
||
@ref{video size syntax,,"Video size" section in the ffmpeg-utils manual,ffmpeg-utils}.
|
||
Default value is @code{600x240}.
|
||
|
||
@item mode
|
||
Set display mode.
|
||
|
||
Available values are:
|
||
@table @samp
|
||
@item point
|
||
Draw a point for each sample.
|
||
|
||
@item line
|
||
Draw a vertical line for each sample.
|
||
|
||
@item p2p
|
||
Draw a point for each sample and a line between them.
|
||
|
||
@item cline
|
||
Draw a centered vertical line for each sample.
|
||
@end table
|
||
|
||
Default value is @code{point}.
|
||
|
||
@item n
|
||
Set the number of samples which are printed on the same column. A
|
||
larger value will decrease the frame rate. Must be a positive
|
||
integer. This option can be set only if the value for @var{rate}
|
||
is not explicitly specified.
|
||
|
||
@item rate, r
|
||
Set the (approximate) output frame rate. This is done by setting the
|
||
option @var{n}. Default value is "25".
|
||
|
||
@item split_channels
|
||
Set if channels should be drawn separately or overlap. Default value is 0.
|
||
|
||
@item colors
|
||
Set colors separated by '|' which are going to be used for drawing of each channel.
|
||
|
||
@item scale
|
||
Set amplitude scale.
|
||
|
||
Available values are:
|
||
@table @samp
|
||
@item lin
|
||
Linear.
|
||
|
||
@item log
|
||
Logarithmic.
|
||
|
||
@item sqrt
|
||
Square root.
|
||
|
||
@item cbrt
|
||
Cubic root.
|
||
@end table
|
||
|
||
Default is linear.
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Output the input file audio and the corresponding video representation
|
||
at the same time:
|
||
@example
|
||
amovie=a.mp3,asplit[out0],showwaves[out1]
|
||
@end example
|
||
|
||
@item
|
||
Create a synthetic signal and show it with showwaves, forcing a
|
||
frame rate of 30 frames per second:
|
||
@example
|
||
aevalsrc=sin(1*2*PI*t)*sin(880*2*PI*t):cos(2*PI*200*t),asplit[out0],showwaves=r=30[out1]
|
||
@end example
|
||
@end itemize
|
||
|
||
@section showwavespic
|
||
|
||
Convert input audio to a single video frame, representing the samples waves.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item size, s
|
||
Specify the video size for the output. For the syntax of this option, check the
|
||
@ref{video size syntax,,"Video size" section in the ffmpeg-utils manual,ffmpeg-utils}.
|
||
Default value is @code{600x240}.
|
||
|
||
@item split_channels
|
||
Set if channels should be drawn separately or overlap. Default value is 0.
|
||
|
||
@item colors
|
||
Set colors separated by '|' which are going to be used for drawing of each channel.
|
||
|
||
@item scale
|
||
Set amplitude scale.
|
||
|
||
Available values are:
|
||
@table @samp
|
||
@item lin
|
||
Linear.
|
||
|
||
@item log
|
||
Logarithmic.
|
||
|
||
@item sqrt
|
||
Square root.
|
||
|
||
@item cbrt
|
||
Cubic root.
|
||
@end table
|
||
|
||
Default is linear.
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Extract a channel split representation of the wave form of a whole audio track
|
||
in a 1024x800 picture using @command{ffmpeg}:
|
||
@example
|
||
ffmpeg -i audio.flac -lavfi showwavespic=split_channels=1:s=1024x800 waveform.png
|
||
@end example
|
||
@end itemize
|
||
|
||
@section sidedata, asidedata
|
||
|
||
Delete frame side data, or select frames based on it.
|
||
|
||
This filter accepts the following options:
|
||
|
||
@table @option
|
||
@item mode
|
||
Set mode of operation of the filter.
|
||
|
||
Can be one of the following:
|
||
|
||
@table @samp
|
||
@item select
|
||
Select every frame with side data of @code{type}.
|
||
|
||
@item delete
|
||
Delete side data of @code{type}. If @code{type} is not set, delete all side
|
||
data in the frame.
|
||
|
||
@end table
|
||
|
||
@item type
|
||
Set side data type used with all modes. Must be set for @code{select} mode. For
|
||
the list of frame side data types, refer to the @code{AVFrameSideDataType} enum
|
||
in @file{libavutil/frame.h}. For example, to choose
|
||
@code{AV_FRAME_DATA_PANSCAN} side data, you must specify @code{PANSCAN}.
|
||
|
||
@end table
|
||
|
||
@section spectrumsynth
|
||
|
||
Sythesize audio from 2 input video spectrums, first input stream represents
|
||
magnitude across time and second represents phase across time.
|
||
The filter will transform from frequency domain as displayed in videos back
|
||
to time domain as presented in audio output.
|
||
|
||
This filter is primarily created for reversing processed @ref{showspectrum}
|
||
filter outputs, but can synthesize sound from other spectrograms too.
|
||
But in such case results are going to be poor if the phase data is not
|
||
available, because in such cases phase data need to be recreated, usually
|
||
its just recreated from random noise.
|
||
For best results use gray only output (@code{channel} color mode in
|
||
@ref{showspectrum} filter) and @code{log} scale for magnitude video and
|
||
@code{lin} scale for phase video. To produce phase, for 2nd video, use
|
||
@code{data} option. Inputs videos should generally use @code{fullframe}
|
||
slide mode as that saves resources needed for decoding video.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item sample_rate
|
||
Specify sample rate of output audio, the sample rate of audio from which
|
||
spectrum was generated may differ.
|
||
|
||
@item channels
|
||
Set number of channels represented in input video spectrums.
|
||
|
||
@item scale
|
||
Set scale which was used when generating magnitude input spectrum.
|
||
Can be @code{lin} or @code{log}. Default is @code{log}.
|
||
|
||
@item slide
|
||
Set slide which was used when generating inputs spectrums.
|
||
Can be @code{replace}, @code{scroll}, @code{fullframe} or @code{rscroll}.
|
||
Default is @code{fullframe}.
|
||
|
||
@item win_func
|
||
Set window function used for resynthesis.
|
||
|
||
@item overlap
|
||
Set window overlap. In range @code{[0, 1]}. Default is @code{1},
|
||
which means optimal overlap for selected window function will be picked.
|
||
|
||
@item orientation
|
||
Set orientation of input videos. Can be @code{vertical} or @code{horizontal}.
|
||
Default is @code{vertical}.
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
First create magnitude and phase videos from audio, assuming audio is stereo with 44100 sample rate,
|
||
then resynthesize videos back to audio with spectrumsynth:
|
||
@example
|
||
ffmpeg -i input.flac -lavfi showspectrum=mode=separate:scale=log:overlap=0.875:color=channel:slide=fullframe:data=magnitude -an -c:v rawvideo magnitude.nut
|
||
ffmpeg -i input.flac -lavfi showspectrum=mode=separate:scale=lin:overlap=0.875:color=channel:slide=fullframe:data=phase -an -c:v rawvideo phase.nut
|
||
ffmpeg -i magnitude.nut -i phase.nut -lavfi spectrumsynth=channels=2:sample_rate=44100:win_func=hann:overlap=0.875:slide=fullframe output.flac
|
||
@end example
|
||
@end itemize
|
||
|
||
@section split, asplit
|
||
|
||
Split input into several identical outputs.
|
||
|
||
@code{asplit} works with audio input, @code{split} with video.
|
||
|
||
The filter accepts a single parameter which specifies the number of outputs. If
|
||
unspecified, it defaults to 2.
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Create two separate outputs from the same input:
|
||
@example
|
||
[in] split [out0][out1]
|
||
@end example
|
||
|
||
@item
|
||
To create 3 or more outputs, you need to specify the number of
|
||
outputs, like in:
|
||
@example
|
||
[in] asplit=3 [out0][out1][out2]
|
||
@end example
|
||
|
||
@item
|
||
Create two separate outputs from the same input, one cropped and
|
||
one padded:
|
||
@example
|
||
[in] split [splitout1][splitout2];
|
||
[splitout1] crop=100:100:0:0 [cropout];
|
||
[splitout2] pad=200:200:100:100 [padout];
|
||
@end example
|
||
|
||
@item
|
||
Create 5 copies of the input audio with @command{ffmpeg}:
|
||
@example
|
||
ffmpeg -i INPUT -filter_complex asplit=5 OUTPUT
|
||
@end example
|
||
@end itemize
|
||
|
||
@section zmq, azmq
|
||
|
||
Receive commands sent through a libzmq client, and forward them to
|
||
filters in the filtergraph.
|
||
|
||
@code{zmq} and @code{azmq} work as a pass-through filters. @code{zmq}
|
||
must be inserted between two video filters, @code{azmq} between two
|
||
audio filters.
|
||
|
||
To enable these filters you need to install the libzmq library and
|
||
headers and configure FFmpeg with @code{--enable-libzmq}.
|
||
|
||
For more information about libzmq see:
|
||
@url{http://www.zeromq.org/}
|
||
|
||
The @code{zmq} and @code{azmq} filters work as a libzmq server, which
|
||
receives messages sent through a network interface defined by the
|
||
@option{bind_address} option.
|
||
|
||
The received message must be in the form:
|
||
@example
|
||
@var{TARGET} @var{COMMAND} [@var{ARG}]
|
||
@end example
|
||
|
||
@var{TARGET} specifies the target of the command, usually the name of
|
||
the filter class or a specific filter instance name.
|
||
|
||
@var{COMMAND} specifies the name of the command for the target filter.
|
||
|
||
@var{ARG} is optional and specifies the optional argument list for the
|
||
given @var{COMMAND}.
|
||
|
||
Upon reception, the message is processed and the corresponding command
|
||
is injected into the filtergraph. Depending on the result, the filter
|
||
will send a reply to the client, adopting the format:
|
||
@example
|
||
@var{ERROR_CODE} @var{ERROR_REASON}
|
||
@var{MESSAGE}
|
||
@end example
|
||
|
||
@var{MESSAGE} is optional.
|
||
|
||
@subsection Examples
|
||
|
||
Look at @file{tools/zmqsend} for an example of a zmq client which can
|
||
be used to send commands processed by these filters.
|
||
|
||
Consider the following filtergraph generated by @command{ffplay}
|
||
@example
|
||
ffplay -dumpgraph 1 -f lavfi "
|
||
color=s=100x100:c=red [l];
|
||
color=s=100x100:c=blue [r];
|
||
nullsrc=s=200x100, zmq [bg];
|
||
[bg][l] overlay [bg+l];
|
||
[bg+l][r] overlay=x=100 "
|
||
@end example
|
||
|
||
To change the color of the left side of the video, the following
|
||
command can be used:
|
||
@example
|
||
echo Parsed_color_0 c yellow | tools/zmqsend
|
||
@end example
|
||
|
||
To change the right side:
|
||
@example
|
||
echo Parsed_color_1 c pink | tools/zmqsend
|
||
@end example
|
||
|
||
@c man end MULTIMEDIA FILTERS
|
||
|
||
@chapter Multimedia Sources
|
||
@c man begin MULTIMEDIA SOURCES
|
||
|
||
Below is a description of the currently available multimedia sources.
|
||
|
||
@section amovie
|
||
|
||
This is the same as @ref{movie} source, except it selects an audio
|
||
stream by default.
|
||
|
||
@anchor{movie}
|
||
@section movie
|
||
|
||
Read audio and/or video stream(s) from a movie container.
|
||
|
||
It accepts the following parameters:
|
||
|
||
@table @option
|
||
@item filename
|
||
The name of the resource to read (not necessarily a file; it can also be a
|
||
device or a stream accessed through some protocol).
|
||
|
||
@item format_name, f
|
||
Specifies the format assumed for the movie to read, and can be either
|
||
the name of a container or an input device. If not specified, the
|
||
format is guessed from @var{movie_name} or by probing.
|
||
|
||
@item seek_point, sp
|
||
Specifies the seek point in seconds. The frames will be output
|
||
starting from this seek point. The parameter is evaluated with
|
||
@code{av_strtod}, so the numerical value may be suffixed by an IS
|
||
postfix. The default value is "0".
|
||
|
||
@item streams, s
|
||
Specifies the streams to read. Several streams can be specified,
|
||
separated by "+". The source will then have as many outputs, in the
|
||
same order. The syntax is explained in the ``Stream specifiers''
|
||
section in the ffmpeg manual. Two special names, "dv" and "da" specify
|
||
respectively the default (best suited) video and audio stream. Default
|
||
is "dv", or "da" if the filter is called as "amovie".
|
||
|
||
@item stream_index, si
|
||
Specifies the index of the video stream to read. If the value is -1,
|
||
the most suitable video stream will be automatically selected. The default
|
||
value is "-1". Deprecated. If the filter is called "amovie", it will select
|
||
audio instead of video.
|
||
|
||
@item loop
|
||
Specifies how many times to read the stream in sequence.
|
||
If the value is 0, the stream will be looped infinitely.
|
||
Default value is "1".
|
||
|
||
Note that when the movie is looped the source timestamps are not
|
||
changed, so it will generate non monotonically increasing timestamps.
|
||
|
||
@item discontinuity
|
||
Specifies the time difference between frames above which the point is
|
||
considered a timestamp discontinuity which is removed by adjusting the later
|
||
timestamps.
|
||
@end table
|
||
|
||
It allows overlaying a second video on top of the main input of
|
||
a filtergraph, as shown in this graph:
|
||
@example
|
||
input -----------> deltapts0 --> overlay --> output
|
||
^
|
||
|
|
||
movie --> scale--> deltapts1 -------+
|
||
@end example
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Skip 3.2 seconds from the start of the AVI file in.avi, and overlay it
|
||
on top of the input labelled "in":
|
||
@example
|
||
movie=in.avi:seek_point=3.2, scale=180:-1, setpts=PTS-STARTPTS [over];
|
||
[in] setpts=PTS-STARTPTS [main];
|
||
[main][over] overlay=16:16 [out]
|
||
@end example
|
||
|
||
@item
|
||
Read from a video4linux2 device, and overlay it on top of the input
|
||
labelled "in":
|
||
@example
|
||
movie=/dev/video0:f=video4linux2, scale=180:-1, setpts=PTS-STARTPTS [over];
|
||
[in] setpts=PTS-STARTPTS [main];
|
||
[main][over] overlay=16:16 [out]
|
||
@end example
|
||
|
||
@item
|
||
Read the first video stream and the audio stream with id 0x81 from
|
||
dvd.vob; the video is connected to the pad named "video" and the audio is
|
||
connected to the pad named "audio":
|
||
@example
|
||
movie=dvd.vob:s=v:0+#0x81 [video] [audio]
|
||
@end example
|
||
@end itemize
|
||
|
||
@subsection Commands
|
||
|
||
Both movie and amovie support the following commands:
|
||
@table @option
|
||
@item seek
|
||
Perform seek using "av_seek_frame".
|
||
The syntax is: seek @var{stream_index}|@var{timestamp}|@var{flags}
|
||
@itemize
|
||
@item
|
||
@var{stream_index}: If stream_index is -1, a default
|
||
stream is selected, and @var{timestamp} is automatically converted
|
||
from AV_TIME_BASE units to the stream specific time_base.
|
||
@item
|
||
@var{timestamp}: Timestamp in AVStream.time_base units
|
||
or, if no stream is specified, in AV_TIME_BASE units.
|
||
@item
|
||
@var{flags}: Flags which select direction and seeking mode.
|
||
@end itemize
|
||
|
||
@item get_duration
|
||
Get movie duration in AV_TIME_BASE units.
|
||
|
||
@end table
|
||
|
||
@c man end MULTIMEDIA SOURCES
|