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Signed-off-by: Paul B Mahol <onemda@gmail.com>
14020 lines
382 KiB
Plaintext
14020 lines
382 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{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.
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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{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{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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@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 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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@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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@item duration, d
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Specify the duration of the cross fade effect. See
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@ref{time duration syntax,,the Time duration section in the ffmpeg-utils(1) manual,ffmpeg-utils}
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for the accepted syntax.
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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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@item curve1
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Set curve for cross fade transition for first stream.
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@item curve2
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Set curve for cross fade transition for second stream.
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For description of available curve types see @ref{afade} filter description.
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@end table
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@subsection Examples
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@itemize
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@item
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Cross fade from one input to another:
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@example
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ffmpeg -i first.flac -i second.flac -filter_complex acrossfade=d=10:c1=exp:c2=exp output.flac
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@end example
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@item
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Cross fade from one input to another but without overlapping:
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@example
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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
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@end itemize
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@section adelay
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Delay one or more audio channels.
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Samples in delayed channel are filled with silence.
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The filter accepts the following option:
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@table @option
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@item delays
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Set list of delays in milliseconds for each channel separated by '|'.
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At least one delay greater than 0 should be provided.
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Unused delays will be silently ignored. If number of given delays is
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smaller than number of channels all remaining channels will not be delayed.
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@end table
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@subsection Examples
|
||
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@itemize
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@item
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Delay first channel by 1.5 seconds, the third channel by 0.5 seconds and leave
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the second channel (and any other channels that may be present) unchanged.
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@example
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adelay=1500|0|500
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@end example
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@end itemize
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@section aecho
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Apply echoing to the input audio.
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Echoes are reflected sound and can occur naturally amongst mountains
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(and sometimes large buildings) when talking or shouting; digital echo
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effects emulate this behaviour and are often used to help fill out the
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sound of a single instrument or vocal. The time difference between the
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original signal and the reflection is the @code{delay}, and the
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loudness of the reflected signal is the @code{decay}.
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||
Multiple echoes can have different delays and decays.
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||
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||
A description of the accepted parameters follows.
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||
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||
@table @option
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@item in_gain
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Set input gain of reflected signal. Default is @code{0.6}.
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||
@item out_gain
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Set output gain of reflected signal. Default is @code{0.3}.
|
||
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||
@item delays
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Set list of time intervals in milliseconds between original signal and reflections
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separated by '|'. Allowed range for each @code{delay} is @code{(0 - 90000.0]}.
|
||
Default is @code{1000}.
|
||
|
||
@item decays
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||
Set list of loudnesses of reflected signals separated by '|'.
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||
Allowed range for each @code{decay} is @code{(0 - 1.0]}.
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||
Default is @code{0.5}.
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||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
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||
@item
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Make it sound as if there are twice as many instruments as are actually playing:
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||
@example
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||
aecho=0.8:0.88:60:0.4
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@end example
|
||
|
||
@item
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||
If delay is very short, then it sound like a (metallic) robot playing music:
|
||
@example
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||
aecho=0.8:0.88:6:0.4
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@end example
|
||
|
||
@item
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||
A longer delay will sound like an open air concert in the mountains:
|
||
@example
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||
aecho=0.8:0.9:1000:0.3
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@end example
|
||
|
||
@item
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||
Same as above but with one more mountain:
|
||
@example
|
||
aecho=0.8:0.9:1000|1800:0.3|0.25
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||
@end example
|
||
@end itemize
|
||
|
||
@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
|
||
|
||
@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 divide 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 raise 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.
|
||
|
||
@item range
|
||
Set the level of gain reduction when the signal is below the threshold.
|
||
|
||
@item threshold
|
||
If a signal rises above this level the gain reduction is released.
|
||
|
||
@item ratio
|
||
Set a ratio about which the signal is reduced.
|
||
|
||
@item attack
|
||
Amount of milliseconds the signal has to rise above the threshold before gain
|
||
reduction stops.
|
||
|
||
@item release
|
||
Amount of milliseconds the signal has to fall below the threshold before the
|
||
reduction is increased again.
|
||
|
||
@item makeup
|
||
Set amount of amplification of signal after processing.
|
||
|
||
@item knee
|
||
Curve the sharp knee around the threshold to enter gain reduction more softly.
|
||
|
||
@item detection
|
||
Choose if exact signal should be taken for detection or an RMS like one.
|
||
|
||
@item link
|
||
Choose if the average level between all channels or the louder channel affects
|
||
the reduction.
|
||
@end table
|
||
|
||
@section alimiter
|
||
|
||
The limiter prevents input signal from raising over a desired threshold.
|
||
This limiter uses lookahead technology to prevent your signal from distorting.
|
||
It means that there is a small delay after 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 limit
|
||
Don't let signals above this level pass the limiter. The removed amplitude is
|
||
added automatically. 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.
|
||
@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
|
||
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.
|
||
@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 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
|
||
|
||
@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
|
||
ffmpeg-resampler manual 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 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
|
||
signal 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
|
||
Peak_level
|
||
RMS_peak
|
||
RMS_trough
|
||
Crest_factor
|
||
Flat_factor
|
||
Peak_count
|
||
Bit_depth
|
||
|
||
and for Overall:
|
||
DC_offset
|
||
Min_level
|
||
Max_level
|
||
Min_difference
|
||
Max_difference
|
||
Mean_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 bellow.
|
||
|
||
@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 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.
|
||
@end table
|
||
|
||
@section astreamsync
|
||
|
||
Forward two audio streams and control the order the buffers are forwarded.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item expr, e
|
||
Set the expression deciding which stream should be
|
||
forwarded next: if the result is negative, the first stream is forwarded; if
|
||
the result is positive or zero, the second stream is forwarded. It can use
|
||
the following variables:
|
||
|
||
@table @var
|
||
@item b1 b2
|
||
number of buffers forwarded so far on each stream
|
||
@item s1 s2
|
||
number of samples forwarded so far on each stream
|
||
@item t1 t2
|
||
current timestamp of each stream
|
||
@end table
|
||
|
||
The default value is @code{t1-t2}, which means to always forward the stream
|
||
that has a smaller timestamp.
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
Stress-test @code{amerge} by randomly sending buffers on the wrong
|
||
input, while avoiding too much of a desynchronization:
|
||
@example
|
||
amovie=file.ogg [a] ; amovie=file.mp3 [b] ;
|
||
[a] [b] astreamsync=(2*random(1))-1+tanh(5*(t1-t2)) [a2] [b2] ;
|
||
[a2] [b2] amerge
|
||
@end example
|
||
|
||
@section asyncts
|
||
|
||
Synchronize audio data with timestamps by squeezing/stretching it and/or
|
||
dropping samples/adding silence when needed.
|
||
|
||
This filter is not built by default, please use @ref{aresample} to do squeezing/stretching.
|
||
|
||
It accepts the following parameters:
|
||
@table @option
|
||
|
||
@item compensate
|
||
Enable stretching/squeezing the data to make it match the timestamps. Disabled
|
||
by default. When disabled, time gaps are covered with silence.
|
||
|
||
@item min_delta
|
||
The minimum difference between timestamps and audio data (in seconds) to trigger
|
||
adding/dropping samples. The default value is 0.1. If you get an imperfect
|
||
sync with this filter, try setting this parameter to 0.
|
||
|
||
@item max_comp
|
||
The maximum compensation in samples per second. Only relevant with compensate=1.
|
||
The default value is 500.
|
||
|
||
@item first_pts
|
||
Assume that the first PTS should be this value. The time base is 1 / sample
|
||
rate. This allows for padding/trimming at the start of the 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
|
||
silence if an audio stream starts after the video stream or to trim any samples
|
||
with a negative PTS due to encoder delay.
|
||
|
||
@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
|
||
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.
|
||
@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
|
||
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.
|
||
@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
|
||
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.
|
||
@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.
|
||
|
||
@section bs2b
|
||
Bauer stereo to binaural transformation, which improves headphone listening of
|
||
stereo audio records.
|
||
|
||
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 channel_layout
|
||
The channel layout of the output stream.
|
||
|
||
@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.
|
||
@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}.
|
||
|
||
@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
|
||
@end itemize
|
||
|
||
@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
|
||
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.
|
||
@end table
|
||
|
||
@subsection Examples
|
||
@itemize
|
||
@item
|
||
Attenuate 10 dB at 1000 Hz, with a bandwidth of 200 Hz:
|
||
@example
|
||
equalizer=f=1000:width_type=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:width_type=q:width=1:g=2,equalizer=f=100:width_type=q:width=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 option:
|
||
|
||
@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 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 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
|
||
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.
|
||
@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
|
||
@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 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
|
||
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.
|
||
@end table
|
||
|
||
@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 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 bellow 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 2. Range is from 1 and 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.
|
||
@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 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 indicate 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}.
|
||
|
||
@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
|
||
@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.
|
||
@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.
|
||
@end table
|
||
|
||
@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 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
|
||
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.
|
||
@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 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 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].
|
||
@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 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.
|
||
|
||
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. Output terminates when shortest 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 exclusion
|
||
@item glow
|
||
@item hardlight
|
||
@item hardmix
|
||
@item lighten
|
||
@item linearlight
|
||
@item multiply
|
||
@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
|
||
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 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 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
|
||
@end table
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Visualizes multi-directionals MVs from P and B-Frames using @command{ffplay}:
|
||
@example
|
||
ffplay -flags2 +export_mvs input.mpg -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 bt601
|
||
BT.601
|
||
|
||
@item smpte240m
|
||
SMPTE-240M
|
||
|
||
@item fcc
|
||
FCC
|
||
@end table
|
||
@end table
|
||
|
||
For example to convert from BT.601 to SMPTE-240M, use the command:
|
||
@example
|
||
colormatrix=bt601:smpte240m
|
||
@end example
|
||
|
||
@section copy
|
||
|
||
Copy the input source unchanged to the output. This is mainly useful for
|
||
testing purposes.
|
||
|
||
@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.
|
||
@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 8bit 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.
|
||
|
||
If there is no key point defined in @code{x=0}, the filter will automatically
|
||
insert a @var{(0;0)} point. In the same way, if there is no key point defined
|
||
in @code{x=1}, the filter will automatically insert a @var{(1;1)} point.
|
||
|
||
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.
|
||
@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='0.5/0.58'
|
||
@end example
|
||
|
||
@item
|
||
Vintage effect:
|
||
@example
|
||
curves=r='0/0.11 .42/.51 1/0.95':g='0.50/0.48':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='0.45/0.53'
|
||
@end example
|
||
@end itemize
|
||
|
||
@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
|
||
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.
|
||
@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
|
||
Allows to limit the maximum change for each plane, default is 65535.
|
||
If 0, plane will remain unchanged.
|
||
@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 4.
|
||
|
||
@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
|
||
Allows to 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 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 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.
|
||
@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
|
||
|
||
@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 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 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 draw
|
||
This option does not exist, please see the timeline system
|
||
|
||
@item alpha
|
||
Draw the text applying alpha blending. The value can
|
||
be either a number between 0.0 and 1.0
|
||
The expression accepts the same variables @var{x, y} do.
|
||
The default value is 1.
|
||
Please see 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 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.
|
||
|
||
Sequence 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. It must take one argument specifying metadata key.
|
||
|
||
@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 two 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.
|
||
|
||
The second argument is an offset added to the timestamp.
|
||
|
||
@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-line_h)/2"
|
||
@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
|
||
|
||
@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
|
||
Allows to 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
|
||
|
||
@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 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
|
||
|
||
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{FREIOR_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 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
|
||
|
||
@item
|
||
Create a linear gradient to use as a mask for another filter, then
|
||
compose with @ref{overlay}. In this example the video will gradually
|
||
become more blurry from the top to the bottom of the y-axis as defined
|
||
by the linear gradient:
|
||
@example
|
||
ffmpeg -i input.mp4 -filter_complex "geq=lum=255*(Y/H),format=gray[grad];[0:v]boxblur=4[blur];[blur][grad]alphamerge[alpha];[0:v][alpha]overlay" output.mp4
|
||
@end example
|
||
@end itemize
|
||
|
||
@section gradfun
|
||
|
||
Fix the banding artifacts that are sometimes introduced into nearly flat
|
||
regions by truncation to 8bit 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.
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item mode
|
||
Set histogram mode.
|
||
|
||
It accepts the following values:
|
||
@table @samp
|
||
@item levels
|
||
Standard histogram that 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.
|
||
|
||
@item color
|
||
Displays chroma values (U/V color placement) in a two dimensional
|
||
graph (which is called a vectorscope). The brighter a pixel in the
|
||
vectorscope, the more pixels of the input frame correspond to that pixel
|
||
(i.e., more pixels have this chroma value). The V component is displayed on
|
||
the horizontal (X) axis, with the leftmost side being V = 0 and the rightmost
|
||
side being V = 255. The U component is displayed on the vertical (Y) axis,
|
||
with the top representing U = 0 and the bottom representing U = 255.
|
||
|
||
The position of a white pixel in the graph corresponds to the chroma value of
|
||
a pixel of the input clip. The graph can therefore be used to read the hue
|
||
(color flavor) and the saturation (the dominance of the hue in the color). As
|
||
the hue of a color changes, it moves around the square. At the center of the
|
||
square the saturation is zero, which means that the corresponding pixel has no
|
||
color. If the amount of a specific color is increased (while leaving the other
|
||
colors unchanged) the saturation increases, and the indicator moves towards
|
||
the edge of the square.
|
||
|
||
@item color2
|
||
Chroma values in vectorscope, similar as @code{color} but actual chroma values
|
||
are displayed.
|
||
|
||
@item waveform
|
||
Per row/column color component graph. 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.
|
||
@end table
|
||
Default value is @code{levels}.
|
||
|
||
@item level_height
|
||
Set height of level in @code{levels}. Default value is @code{200}.
|
||
Allowed range is [50, 2048].
|
||
|
||
@item scale_height
|
||
Set height of color scale in @code{levels}. Default value is @code{12}.
|
||
Allowed range is [0, 40].
|
||
|
||
@item step
|
||
Set step for @code{waveform} mode. Smaller values are useful to find out how
|
||
many values of the same luminance are distributed across input rows/columns.
|
||
Default value is @code{10}. Allowed range is [1, 255].
|
||
|
||
@item waveform_mode
|
||
Set mode for @code{waveform}. Can be either @code{row}, or @code{column}.
|
||
Default is @code{row}.
|
||
|
||
@item waveform_mirror
|
||
Set mirroring mode for @code{waveform}. @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{0} (unmirrored).
|
||
|
||
@item display_mode
|
||
Set display mode for @code{waveform} and @code{levels}.
|
||
It accepts the following values:
|
||
@table @samp
|
||
@item parade
|
||
Display separate graph for the color components side by side in
|
||
@code{row} waveform mode or one below the other in @code{column} waveform mode
|
||
for @code{waveform} histogram mode. For @code{levels} histogram mode,
|
||
per color component graphs are placed below each other.
|
||
|
||
Using this display mode in @code{waveform} histogram 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.
|
||
|
||
@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 in @code{waveform} histogram 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.
|
||
@end table
|
||
Default is @code{parade}.
|
||
|
||
@item levels_mode
|
||
Set mode for @code{levels}. Can be either @code{linear}, or @code{logarithmic}.
|
||
Default is @code{linear}.
|
||
|
||
@item components
|
||
Set what color components to display for mode @code{levels}.
|
||
Default is @code{7}.
|
||
@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 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 nb_inputs
|
||
Set number of input streams. Default is 2.
|
||
@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 idet
|
||
|
||
Detect video interlacing type.
|
||
|
||
This filter tries to detect if the input frames as interlaced, progressive,
|
||
top or bottom field first. It will also try and 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 repeat_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 it's
|
||
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
|
||
Allows to 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
|
||
Enable (default) or disable the vertical lowpass filter to avoid twitter
|
||
interlacing and reduce moire patterns.
|
||
@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.
|
||
|
||
@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 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
|
||
@end itemize
|
||
|
||
@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 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 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}.
|
||
|
||
@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 RGB output
|
||
@end table
|
||
|
||
Default value is @samp{yuv420}.
|
||
|
||
@item rgb @emph{(deprecated)}
|
||
If set to 1, force the filter to accept inputs in the RGB
|
||
color space. Default value is 0. This option is deprecated, use
|
||
@option{format} instead.
|
||
|
||
@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.
|
||
|
||
@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".
|
||
@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.
|
||
@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}.
|
||
@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.
|
||
@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
|
||
@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 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 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.
|
||
@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 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.
|
||
@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 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, areverse
|
||
|
||
Reverse a 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 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 0.1-4.0. 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 0.1-2.0 range.
|
||
|
||
@item chroma_strength, cs
|
||
Set chroma maximum difference between pixels to still be considered,
|
||
must be a value in the 0.1-100.0 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 value is 0, the input width is used for the output.
|
||
|
||
If one of the values is -1, the scale filter will use a value that
|
||
maintains the aspect ratio of the input image, calculated from the
|
||
other specified dimension. If both of them are -1, the input size is
|
||
used
|
||
|
||
If one of the values is -n with n > 1, the scale filter will also 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.
|
||
|
||
See below for the list of accepted constants for use in the dimension
|
||
expression.
|
||
|
||
@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 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 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.
|
||
|
||
@subsection Examples
|
||
|
||
@itemize
|
||
@item
|
||
Scale a subtitle stream to match the main video in size before overlaying
|
||
@example
|
||
'scale2ref[b][a];[a][b]overlay'
|
||
@end example
|
||
@end itemize
|
||
|
||
@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
|
||
setdar=dar=1.77777
|
||
@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 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.
|
||
|
||
Swap the second and third planes of the input:
|
||
@example
|
||
ffmpeg -i INPUT -vf shuffleplanes=0:2:1:3 OUTPUT
|
||
@end example
|
||
|
||
@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].
|
||
@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{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 1.0.
|
||
|
||
@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 1.0.
|
||
|
||
@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 0.
|
||
@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.
|
||
@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)
|
||
|
||
Default value is @samp{sbsl}.
|
||
@end table
|
||
|
||
@item out
|
||
Set stereoscopic image format of output.
|
||
|
||
Available values for output image formats are all the input formats as well as:
|
||
@table @samp
|
||
@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
|
||
@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 bellow (left eye above, right eye below) to side by side crosseye.
|
||
@example
|
||
stereo3d=abl:sbsr
|
||
@end example
|
||
@end itemize
|
||
|
||
@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 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 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_odd, 1
|
||
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 drop_even, 2
|
||
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 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 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.
|
||
|
||
Vertical low-pass filtering can only be enabled for @option{mode}
|
||
@var{interleave_top} and @var{interleave_bottom}.
|
||
|
||
@end table
|
||
@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
|
||
|
||
|
||
@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 63. 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 63. 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 63. 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 63. 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 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}.
|
||
|
||
@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.
|
||
@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 and color3 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
|
||
@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 nb_inputs
|
||
Set number of input streams. Default is 2.
|
||
@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 parade
|
||
Display separate graph for the color components side by side in
|
||
@code{row} mode or one below the other in @code{column} 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{parade}.
|
||
|
||
@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 achroma
|
||
Similar as above, but shows difference between blue and red chroma.
|
||
|
||
@item color
|
||
Displays actual color value on waveform.
|
||
@end table
|
||
@end table
|
||
|
||
@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'.
|
||
@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
|
||
@end itemize
|
||
|
||
@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.
|
||
@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
|
||
|
||
@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}
|
||
@section allrgb, allyuv, color, haldclutsrc, nullsrc, rgbtestsrc, smptebars, smptehdbars, testsrc
|
||
|
||
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 sources accept the following parameters:
|
||
|
||
@table @option
|
||
|
||
@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 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.
|
||
@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]}.
|
||
@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 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
|
||
|
||
@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
|
||
|
||
@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 a 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 drop 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 will send 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 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 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)
|
||
|
||
@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
|
||
@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
|
||
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 constant Q transform with
|
||
Brown-Puckette algorithm), with musical tone scale, from E0 to D#10 (10 octaves).
|
||
|
||
The filter accepts the following options:
|
||
|
||
@table @option
|
||
@item volume
|
||
Specify transform volume (multiplier) expression. The expression can contain
|
||
variables:
|
||
@table @option
|
||
@item frequency, freq, f
|
||
the frequency where transform is evaluated
|
||
@item timeclamp, tc
|
||
value of 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 tlength
|
||
Specify transform length expression. The expression can contain variables:
|
||
@table @option
|
||
@item frequency, freq, f
|
||
the frequency where transform is evaluated
|
||
@item timeclamp, tc
|
||
value of timeclamp option
|
||
@end table
|
||
Default value is @code{384/f*tc/(384/f+tc)}.
|
||
|
||
@item timeclamp
|
||
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 value is [0.1, 1.0]. Default value is @code{0.17}.
|
||
|
||
@item coeffclamp
|
||
Specify the transform coeffclamp. If coeffclamp is lower, transform is
|
||
more accurate, otherwise transform is faster. Acceptable value is [0.1, 10.0].
|
||
Default value is @code{1.0}.
|
||
|
||
@item gamma
|
||
Specify gamma. Lower gamma makes the spectrum more contrast, higher gamma
|
||
makes the spectrum having more range. Acceptable value is [1.0, 7.0].
|
||
Default value is @code{3.0}.
|
||
|
||
@item gamma2
|
||
Specify gamma of bargraph. Acceptable value is [1.0, 7.0].
|
||
Default value is @code{1.0}.
|
||
|
||
@item fontfile
|
||
Specify font file for use with freetype. If not specified, use embedded font.
|
||
|
||
@item fontcolor
|
||
Specify font color expression. This is arithmetic expression that should return
|
||
integer value 0xRRGGBB. The expression can contain variables:
|
||
@table @option
|
||
@item frequency, freq, f
|
||
the frequency where transform is evaluated
|
||
@item timeclamp, tc
|
||
value of 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 fullhd
|
||
If set to 1 (the default), the video size is 1920x1080 (full HD),
|
||
if set to 0, the video size is 960x540. Use this option to make CPU usage lower.
|
||
|
||
@item fps
|
||
Specify video fps. Default value is @code{25}.
|
||
|
||
@item count
|
||
Specify number of transform per frame, so there are fps*count transforms
|
||
per second. Note that audio data rate must be divisible by fps*count.
|
||
Default value is @code{6}.
|
||
|
||
@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 960x540 and lower CPU usage:
|
||
@example
|
||
ffplay -f lavfi 'amovie=a.mp3, asplit [a][out1]; [a] showcqt=fullhd=0:count=3 [out0]'
|
||
@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 (and slower):
|
||
@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
|
||
B-weighting of equal loudness
|
||
@example
|
||
volume=16*b_weighting(f)
|
||
@end example
|
||
|
||
@item
|
||
Lower Q factor
|
||
@example
|
||
tlength=100/f*tc/(100/f+tc)
|
||
@end example
|
||
|
||
@item
|
||
Custom fontcolor, C-note is colored green, others are colored blue
|
||
@example
|
||
fontcolor='if(mod(floor(midi(f)+0.5),12), 0x0000FF, g(1))'
|
||
@end example
|
||
|
||
@item
|
||
Custom gamma, now spectrum is linear to the amplitude.
|
||
@example
|
||
gamma=2:gamma2=2
|
||
@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
|
||
@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.
|
||
@end table
|
||
|
||
@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
|
||
@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 is displayed using the same 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
|
||
@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 none
|
||
No samples pre-processing (do not expect this to be faster)
|
||
@item hann
|
||
Hann window
|
||
@item hamming
|
||
Hamming window
|
||
@item blackman
|
||
Blackman window
|
||
@end table
|
||
|
||
Default value is @code{hann}.
|
||
@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 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 [40, 1080]. Default is 400.
|
||
|
||
@item h
|
||
Set channel height, allowed range is [1, 100]. Default is 20.
|
||
|
||
@item f
|
||
Set fade, allowed range is [1, 255]. Default is 20.
|
||
|
||
@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 CHANNEL
|
||
Current channel number, starting from 0.
|
||
@end table
|
||
|
||
@item t
|
||
If set, displays channel names. Default is enabled.
|
||
@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.
|
||
|
||
@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.
|
||
@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 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 less than 1, the stream will be read again and again.
|
||
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.
|
||
@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
|
||
|
||
@c man end MULTIMEDIA SOURCES
|