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1600f85cbc
Signed-off-by: Stefano Sabatini <stefasab@gmail.com>
373 lines
13 KiB
Plaintext
373 lines
13 KiB
Plaintext
All the numerical options, if not specified otherwise, accept a string
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representing a number as input, which may be followed by one of the SI
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unit prefixes, for example: 'K', 'M', or 'G'.
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If 'i' is appended to the SI unit prefix, the complete prefix will be
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interpreted as a unit prefix for binary multiples, which are based on
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powers of 1024 instead of powers of 1000. Appending 'B' to the SI unit
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prefix multiplies the value by 8. This allows using, for example:
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'KB', 'MiB', 'G' and 'B' as number suffixes.
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Options which do not take arguments are boolean options, and set the
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corresponding value to true. They can be set to false by prefixing
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the option name with "no". For example using "-nofoo"
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will set the boolean option with name "foo" to false.
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@anchor{Stream specifiers}
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@section Stream specifiers
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Some options are applied per-stream, e.g. bitrate or codec. Stream specifiers
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are used to precisely specify which stream(s) a given option belongs to.
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A stream specifier is a string generally appended to the option name and
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separated from it by a colon. E.g. @code{-codec:a:1 ac3} contains the
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@code{a:1} stream specifier, which matches the second audio stream. Therefore, it
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would select the ac3 codec for the second audio stream.
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A stream specifier can match several streams, so that the option is applied to all
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of them. E.g. the stream specifier in @code{-b:a 128k} matches all audio
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streams.
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An empty stream specifier matches all streams. For example, @code{-codec copy}
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or @code{-codec: copy} would copy all the streams without reencoding.
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Possible forms of stream specifiers are:
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@table @option
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@item @var{stream_index}
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Matches the stream with this index. E.g. @code{-threads:1 4} would set the
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thread count for the second stream to 4.
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@item @var{stream_type}[:@var{stream_index}]
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@var{stream_type} is one of following: 'v' for video, 'a' for audio, 's' for subtitle,
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'd' for data, and 't' for attachments. If @var{stream_index} is given, then it matches
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stream number @var{stream_index} of this type. Otherwise, it matches all
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streams of this type.
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@item p:@var{program_id}[:@var{stream_index}]
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If @var{stream_index} is given, then it matches the stream with number @var{stream_index}
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in the program with the id @var{program_id}. Otherwise, it matches all streams in the
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program.
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@item #@var{stream_id} or i:@var{stream_id}
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Match the stream by stream id (e.g. PID in MPEG-TS container).
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@item m:@var{key}[:@var{value}]
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Matches streams with the metadata tag @var{key} having the specified value. If
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@var{value} is not given, matches streams that contain the given tag with any
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value.
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Note that in @command{ffmpeg}, matching by metadata will only work properly for
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input files.
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@end table
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@section Generic options
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These options are shared amongst the ff* tools.
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@table @option
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@item -L
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Show license.
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@item -h, -?, -help, --help [@var{arg}]
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Show help. An optional parameter may be specified to print help about a specific
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item. If no argument is specified, only basic (non advanced) tool
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options are shown.
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Possible values of @var{arg} are:
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@table @option
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@item long
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Print advanced tool options in addition to the basic tool options.
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@item full
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Print complete list of options, including shared and private options
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for encoders, decoders, demuxers, muxers, filters, etc.
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@item decoder=@var{decoder_name}
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Print detailed information about the decoder named @var{decoder_name}. Use the
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@option{-decoders} option to get a list of all decoders.
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@item encoder=@var{encoder_name}
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Print detailed information about the encoder named @var{encoder_name}. Use the
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@option{-encoders} option to get a list of all encoders.
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@item demuxer=@var{demuxer_name}
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Print detailed information about the demuxer named @var{demuxer_name}. Use the
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@option{-formats} option to get a list of all demuxers and muxers.
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@item muxer=@var{muxer_name}
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Print detailed information about the muxer named @var{muxer_name}. Use the
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@option{-formats} option to get a list of all muxers and demuxers.
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@item filter=@var{filter_name}
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Print detailed information about the filter name @var{filter_name}. Use the
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@option{-filters} option to get a list of all filters.
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@end table
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@item -version
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Show version.
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@item -formats
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Show available formats (including devices).
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@item -devices
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Show available devices.
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@item -codecs
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Show all codecs known to libavcodec.
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Note that the term 'codec' is used throughout this documentation as a shortcut
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for what is more correctly called a media bitstream format.
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@item -decoders
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Show available decoders.
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@item -encoders
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Show all available encoders.
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@item -bsfs
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Show available bitstream filters.
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@item -protocols
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Show available protocols.
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@item -filters
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Show available libavfilter filters.
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@item -pix_fmts
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Show available pixel formats.
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@item -sample_fmts
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Show available sample formats.
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@item -layouts
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Show channel names and standard channel layouts.
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@item -colors
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Show recognized color names.
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@item -sources @var{device}[,@var{opt1}=@var{val1}[,@var{opt2}=@var{val2}]...]
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Show autodetected sources of the intput device.
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Some devices may provide system-dependent source names that cannot be autodetected.
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The returned list cannot be assumed to be always complete.
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@example
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ffmpeg -sources pulse,server=192.168.0.4
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@end example
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@item -sinks @var{device}[,@var{opt1}=@var{val1}[,@var{opt2}=@var{val2}]...]
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Show autodetected sinks of the output device.
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Some devices may provide system-dependent sink names that cannot be autodetected.
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The returned list cannot be assumed to be always complete.
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@example
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ffmpeg -sinks pulse,server=192.168.0.4
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@end example
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@item -loglevel [repeat+]@var{loglevel} | -v [repeat+]@var{loglevel}
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Set the logging level used by the library.
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Adding "repeat+" indicates that repeated log output should not be compressed
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to the first line and the "Last message repeated n times" line will be
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omitted. "repeat" can also be used alone.
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If "repeat" is used alone, and with no prior loglevel set, the default
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loglevel will be used. If multiple loglevel parameters are given, using
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'repeat' will not change the loglevel.
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@var{loglevel} is a string or a number containing one of the following values:
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@table @samp
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@item quiet, -8
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Show nothing at all; be silent.
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@item panic, 0
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Only show fatal errors which could lead the process to crash, such as
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and assert failure. This is not currently used for anything.
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@item fatal, 8
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Only show fatal errors. These are errors after which the process absolutely
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cannot continue after.
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@item error, 16
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Show all errors, including ones which can be recovered from.
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@item warning, 24
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Show all warnings and errors. Any message related to possibly
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incorrect or unexpected events will be shown.
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@item info, 32
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Show informative messages during processing. This is in addition to
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warnings and errors. This is the default value.
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@item verbose, 40
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Same as @code{info}, except more verbose.
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@item debug, 48
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Show everything, including debugging information.
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@end table
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By default the program logs to stderr, if coloring is supported by the
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terminal, colors are used to mark errors and warnings. Log coloring
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can be disabled setting the environment variable
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@env{AV_LOG_FORCE_NOCOLOR} or @env{NO_COLOR}, or can be forced setting
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the environment variable @env{AV_LOG_FORCE_COLOR}.
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The use of the environment variable @env{NO_COLOR} is deprecated and
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will be dropped in a following FFmpeg version.
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@item -report
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Dump full command line and console output to a file named
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@code{@var{program}-@var{YYYYMMDD}-@var{HHMMSS}.log} in the current
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directory.
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This file can be useful for bug reports.
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It also implies @code{-loglevel verbose}.
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Setting the environment variable @env{FFREPORT} to any value has the
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same effect. If the value is a ':'-separated key=value sequence, these
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options will affect the report; option values must be escaped if they
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contain special characters or the options delimiter ':' (see the
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``Quoting and escaping'' section in the ffmpeg-utils manual).
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The following options are recognized:
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@table @option
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@item file
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set the file name to use for the report; @code{%p} is expanded to the name
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of the program, @code{%t} is expanded to a timestamp, @code{%%} is expanded
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to a plain @code{%}
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@item level
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set the log verbosity level using a numerical value (see @code{-loglevel}).
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@end table
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For example, to output a report to a file named @file{ffreport.log}
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using a log level of @code{32} (alias for log level @code{info}):
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@example
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FFREPORT=file=ffreport.log:level=32 ffmpeg -i input output
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@end example
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Errors in parsing the environment variable are not fatal, and will not
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appear in the report.
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@item -hide_banner
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Suppress printing banner.
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All FFmpeg tools will normally show a copyright notice, build options
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and library versions. This option can be used to suppress printing
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this information.
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@item -cpuflags flags (@emph{global})
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Allows setting and clearing cpu flags. This option is intended
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for testing. Do not use it unless you know what you're doing.
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@example
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ffmpeg -cpuflags -sse+mmx ...
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ffmpeg -cpuflags mmx ...
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ffmpeg -cpuflags 0 ...
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@end example
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Possible flags for this option are:
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@table @samp
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@item x86
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@table @samp
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@item mmx
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@item mmxext
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@item sse
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@item sse2
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@item sse2slow
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@item sse3
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@item sse3slow
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@item ssse3
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@item atom
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@item sse4.1
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@item sse4.2
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@item avx
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@item xop
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@item fma4
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@item 3dnow
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@item 3dnowext
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@item cmov
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@end table
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@item ARM
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@table @samp
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@item armv5te
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@item armv6
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@item armv6t2
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@item vfp
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@item vfpv3
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@item neon
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@end table
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@item PowerPC
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@table @samp
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@item altivec
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@end table
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@item Specific Processors
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@table @samp
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@item pentium2
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@item pentium3
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@item pentium4
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@item k6
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@item k62
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@item athlon
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@item athlonxp
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@item k8
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@end table
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@end table
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@item -opencl_bench
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This option is used to benchmark all available OpenCL devices and print the
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results. This option is only available when FFmpeg has been compiled with
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@code{--enable-opencl}.
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When FFmpeg is configured with @code{--enable-opencl}, the options for the
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global OpenCL context are set via @option{-opencl_options}. See the
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"OpenCL Options" section in the ffmpeg-utils manual for the complete list of
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supported options. Amongst others, these options include the ability to select
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a specific platform and device to run the OpenCL code on. By default, FFmpeg
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will run on the first device of the first platform. While the options for the
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global OpenCL context provide flexibility to the user in selecting the OpenCL
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device of their choice, most users would probably want to select the fastest
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OpenCL device for their system.
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This option assists the selection of the most efficient configuration by
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identifying the appropriate device for the user's system. The built-in
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benchmark is run on all the OpenCL devices and the performance is measured for
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each device. The devices in the results list are sorted based on their
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performance with the fastest device listed first. The user can subsequently
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invoke @command{ffmpeg} using the device deemed most appropriate via
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@option{-opencl_options} to obtain the best performance for the OpenCL
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accelerated code.
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Typical usage to use the fastest OpenCL device involve the following steps.
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Run the command:
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@example
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ffmpeg -opencl_bench
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@end example
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Note down the platform ID (@var{pidx}) and device ID (@var{didx}) of the first
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i.e. fastest device in the list.
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Select the platform and device using the command:
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@example
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ffmpeg -opencl_options platform_idx=@var{pidx}:device_idx=@var{didx} ...
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@end example
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@item -opencl_options options (@emph{global})
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Set OpenCL environment options. This option is only available when
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FFmpeg has been compiled with @code{--enable-opencl}.
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@var{options} must be a list of @var{key}=@var{value} option pairs
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separated by ':'. See the ``OpenCL Options'' section in the
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ffmpeg-utils manual for the list of supported options.
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@end table
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@section AVOptions
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These options are provided directly by the libavformat, libavdevice and
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libavcodec libraries. To see the list of available AVOptions, use the
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@option{-help} option. They are separated into two categories:
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@table @option
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@item generic
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These options can be set for any container, codec or device. Generic options
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are listed under AVFormatContext options for containers/devices and under
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AVCodecContext options for codecs.
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@item private
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These options are specific to the given container, device or codec. Private
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options are listed under their corresponding containers/devices/codecs.
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@end table
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For example to write an ID3v2.3 header instead of a default ID3v2.4 to
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an MP3 file, use the @option{id3v2_version} private option of the MP3
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muxer:
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@example
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ffmpeg -i input.flac -id3v2_version 3 out.mp3
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@end example
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All codec AVOptions are per-stream, and thus a stream specifier
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should be attached to them.
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Note: the @option{-nooption} syntax cannot be used for boolean
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AVOptions, use @option{-option 0}/@option{-option 1}.
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Note: the old undocumented way of specifying per-stream AVOptions by
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prepending v/a/s to the options name is now obsolete and will be
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removed soon.
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