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\input texinfo @c -*- texinfo -*-
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@settitle FFmpeg Documentation
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@titlepage
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@sp 7
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@center @titlefont{FFmpeg Documentation}
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@sp 3
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@end titlepage
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@chapter Introduction
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FFmpeg is a very fast video and audio converter. It can also grab from
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a live audio/video source.
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The command line interface is designed to be intuitive, in the sense
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that FFmpeg tries to figure out all parameters that can possibly be
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derived automatically. You usually only have to specify the target
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bitrate you want.
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FFmpeg can also convert from any sample rate to any other, and resize
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video on the fly with a high quality polyphase filter.
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@chapter Quick Start
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@c man begin EXAMPLES
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@section Video and Audio grabbing
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FFmpeg can use a video4linux compatible video source and any Open Sound
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System audio source:
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@example
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ffmpeg /tmp/out.mpg
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@end example
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Note that you must activate the right video source and channel before
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launching FFmpeg with any TV viewer such as xawtv
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(@url{http://bytesex.org/xawtv/}) by Gerd Knorr. You also
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have to set the audio recording levels correctly with a
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standard mixer.
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@section Video and Audio file format conversion
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* FFmpeg can use any supported file format and protocol as input:
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Examples:
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* You can use YUV files as input:
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@example
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ffmpeg -i /tmp/test%d.Y /tmp/out.mpg
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@end example
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It will use the files:
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@example
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/tmp/test0.Y, /tmp/test0.U, /tmp/test0.V,
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/tmp/test1.Y, /tmp/test1.U, /tmp/test1.V, etc...
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@end example
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The Y files use twice the resolution of the U and V files. They are
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raw files, without header. They can be generated by all decent video
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decoders. You must specify the size of the image with the @option{-s} option
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if FFmpeg cannot guess it.
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* You can input from a raw YUV420P file:
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@example
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ffmpeg -i /tmp/test.yuv /tmp/out.avi
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@end example
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test.yuv is a file containing raw YUV planar data. Each frame is composed
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of the Y plane followed by the U and V planes at half vertical and
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horizontal resolution.
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* You can output to a raw YUV420P file:
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@example
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ffmpeg -i mydivx.avi hugefile.yuv
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@end example
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* You can set several input files and output files:
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@example
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ffmpeg -i /tmp/a.wav -s 640x480 -i /tmp/a.yuv /tmp/a.mpg
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@end example
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Converts the audio file a.wav and the raw YUV video file a.yuv
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to MPEG file a.mpg.
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* You can also do audio and video conversions at the same time:
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@example
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ffmpeg -i /tmp/a.wav -ar 22050 /tmp/a.mp2
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@end example
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Converts a.wav to MPEG audio at 22050Hz sample rate.
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* You can encode to several formats at the same time and define a
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mapping from input stream to output streams:
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@example
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ffmpeg -i /tmp/a.wav -ab 64 /tmp/a.mp2 -ab 128 /tmp/b.mp2 -map 0:0 -map 0:0
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@end example
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Converts a.wav to a.mp2 at 64 kbits and to b.mp2 at 128 kbits. '-map
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file:index' specifies which input stream is used for each output
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stream, in the order of the definition of output streams.
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* You can transcode decrypted VOBs
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@example
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ffmpeg -i snatch_1.vob -f avi -vcodec mpeg4 -b 800 -g 300 -bf 2 -acodec mp3 -ab 128 snatch.avi
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@end example
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This is a typical DVD ripping example; the input is a VOB file, the
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output an AVI file with MPEG-4 video and MP3 audio. Note that in this
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command we use B-frames so the MPEG-4 stream is DivX5 compatible, and
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GOP size is 300 which means one intra frame every 10 seconds for 29.97fps
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input video. Furthermore, the audio stream is MP3-encoded so you need
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to enable LAME support by passing @code{--enable-mp3lame} to configure.
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The mapping is particularly useful for DVD transcoding
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to get the desired audio language.
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NOTE: To see the supported input formats, use @code{ffmpeg -formats}.
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@c man end
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@chapter Invocation
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@section Syntax
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The generic syntax is:
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@example
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@c man begin SYNOPSIS
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ffmpeg [[infile options][@option{-i} @var{infile}]]... @{[outfile options] @var{outfile}@}...
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@c man end
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@end example
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@c man begin DESCRIPTION
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If no input file is given, audio/video grabbing is done.
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As a general rule, options are applied to the next specified
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file. For example, if you give the @option{-b 64} option, it sets the video
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bitrate of the next file. The format option may be needed for raw input
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files.
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By default, FFmpeg tries to convert as losslessly as possible: It
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uses the same audio and video parameters for the outputs as the one
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specified for the inputs.
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@c man end
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@c man begin OPTIONS
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@section Main options
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@table @option
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@item -L
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Show license.
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@item -h
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Show help.
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@item -formats
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Show available formats, codecs, protocols, ...
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@item -f fmt
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Force format.
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@item -i filename
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input filename
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@item -y
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Overwrite output files.
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@item -t duration
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Set the recording time in seconds.
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@code{hh:mm:ss[.xxx]} syntax is also supported.
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@item -ss position
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Seek to given time position in seconds.
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@code{hh:mm:ss[.xxx]} syntax is also supported.
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@item -title string
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Set the title.
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@item -author string
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Set the author.
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@item -copyright string
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Set the copyright.
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@item -comment string
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Set the comment.
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@item -target type
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Specify target file type ("vcd", "svcd", "dvd", "dv", "pal-vcd",
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"ntsc-svcd", ... ). All the format options (bitrate, codecs,
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buffer sizes) are then set automatically. You can just type:
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@example
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ffmpeg -i myfile.avi -target vcd /tmp/vcd.mpg
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@end example
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Nevertheless you can specify additional options as long as you know
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they do not conflict with the standard, as in:
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@example
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ffmpeg -i myfile.avi -target vcd -bf 2 /tmp/vcd.mpg
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@end example
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@item -hq
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Activate high quality settings.
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@item -itsoffset offset
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Set the input time offset in seconds.
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@code{[-]hh:mm:ss[.xxx]} syntax is also supported.
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This option affects all the input files that follow it.
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The offset is added to the timestamps of the input files.
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Specifying a positive offset means that the corresponding
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streams are delayed by 'offset' seconds.
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@end table
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@section Video Options
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@table @option
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@item -b bitrate
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Set the video bitrate in kbit/s (default = 200 kb/s).
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@item -r fps
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Set frame rate (default = 25).
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@item -s size
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Set frame size. The format is @samp{wxh} (default = 160x128).
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The following abbreviations are recognized:
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@table @samp
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@item sqcif
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128x96
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@item qcif
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176x144
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@item cif
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352x288
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@item 4cif
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704x576
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@end table
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@item -aspect aspect
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Set aspect ratio (4:3, 16:9 or 1.3333, 1.7777).
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@item -croptop size
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Set top crop band size (in pixels).
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@item -cropbottom size
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Set bottom crop band size (in pixels).
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@item -cropleft size
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Set left crop band size (in pixels).
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@item -cropright size
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Set right crop band size (in pixels).
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@item -padtop size
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Set top pad band size (in pixels).
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@item -padbottom size
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Set bottom pad band size (in pixels).
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@item -padleft size
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Set left pad band size (in pixels).
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@item -padright size
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Set right pad band size (in pixels).
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@item -padcolor (hex color)
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Set color of padded bands. The value for padcolor is expressed
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as a six digit hexadecimal number where the first two digits
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represent red, the middle two digits green and last two digits
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blue (default = 000000 (black)).
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@item -vn
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Disable video recording.
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@item -bt tolerance
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Set video bitrate tolerance (in kbit/s).
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@item -maxrate bitrate
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Set max video bitrate tolerance (in kbit/s).
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@item -minrate bitrate
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Set min video bitrate tolerance (in kbit/s).
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@item -bufsize size
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Set rate control buffer size (in kbit).
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@item -vcodec codec
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Force video codec to @var{codec}. Use the @code{copy} special value to
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tell that the raw codec data must be copied as is.
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@item -sameq
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Use same video quality as source (implies VBR).
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@item -pass n
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Select the pass number (1 or 2). It is useful to do two pass
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encoding. The statistics of the video are recorded in the first
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pass and the video is generated at the exact requested bitrate
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in the second pass.
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@item -passlogfile file
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Set two pass logfile name to @var{file}.
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@end table
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@section Advanced Video Options
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@table @option
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@item -g gop_size
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Set the group of pictures size.
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@item -intra
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Use only intra frames.
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@item -qscale q
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Use fixed video quantiser scale (VBR).
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@item -qmin q
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minimum video quantiser scale (VBR)
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@item -qmax q
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maximum video quantiser scale (VBR)
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@item -qdiff q
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maximum difference between the quantiser scales (VBR)
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@item -qblur blur
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video quantiser scale blur (VBR)
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@item -qcomp compression
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video quantiser scale compression (VBR)
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@item -rc_init_cplx complexity
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initial complexity for single pass encoding
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@item -b_qfactor factor
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qp factor between P- and B-frames
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@item -i_qfactor factor
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qp factor between P- and I-frames
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@item -b_qoffset offset
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qp offset between P- and B-frames
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@item -i_qoffset offset
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qp offset between P- and I-frames
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@item -rc_eq equation
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Set rate control equation (@pxref{FFmpeg formula
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evaluator}) (default = @code{tex^qComp}).
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@item -rc_override override
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rate control override for specific intervals
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@item -me method
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Set motion estimation method to @var{method}.
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Available methods are (from lowest to best quality):
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@table @samp
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@item zero
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Try just the (0, 0) vector.
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@item phods
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@item log
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@item x1
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@item epzs
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(default method)
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@item full
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exhaustive search (slow and marginally better than epzs)
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@end table
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@item -dct_algo algo
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Set DCT algorithm to @var{algo}. Available values are:
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@table @samp
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@item 0
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FF_DCT_AUTO (default)
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@item 1
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FF_DCT_FASTINT
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@item 2
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FF_DCT_INT
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@item 3
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FF_DCT_MMX
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@item 4
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FF_DCT_MLIB
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@item 5
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FF_DCT_ALTIVEC
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@end table
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@item -idct_algo algo
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Set IDCT algorithm to @var{algo}. Available values are:
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@table @samp
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@item 0
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FF_IDCT_AUTO (default)
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@item 1
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FF_IDCT_INT
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@item 2
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FF_IDCT_SIMPLE
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@item 3
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FF_IDCT_SIMPLEMMX
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@item 4
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FF_IDCT_LIBMPEG2MMX
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@item 5
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FF_IDCT_PS2
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@item 6
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FF_IDCT_MLIB
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@item 7
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FF_IDCT_ARM
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@item 8
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FF_IDCT_ALTIVEC
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@item 9
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FF_IDCT_SH4
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@item 10
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FF_IDCT_SIMPLEARM
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@end table
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@item -er n
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Set error resilience to @var{n}.
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@table @samp
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@item 1
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FF_ER_CAREFUL (default)
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@item 2
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FF_ER_COMPLIANT
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@item 3
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FF_ER_AGGRESSIVE
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@item 4
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FF_ER_VERY_AGGRESSIVE
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@end table
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@item -ec bit_mask
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Set error concealment to @var{bit_mask}. @var{bit_mask} is a bit mask of
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the following values:
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@table @samp
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@item 1
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FF_EC_GUESS_MVS (default = enabled)
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@item 2
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FF_EC_DEBLOCK (default = enabled)
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@end table
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@item -bf frames
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Use 'frames' B-frames (supported for MPEG-1, MPEG-2 and MPEG-4).
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@item -mbd mode
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macroblock decision
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@table @samp
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@item 0
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FF_MB_DECISION_SIMPLE: Use mb_cmp (cannot change it yet in FFmpeg).
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@item 1
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FF_MB_DECISION_BITS: Choose the one which needs the fewest bits.
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@item 2
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FF_MB_DECISION_RD: rate distortion
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@end table
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@item -4mv
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Use four motion vector by macroblock (MPEG-4 only).
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@item -part
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Use data partitioning (MPEG-4 only).
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@item -bug param
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Work around encoder bugs that are not auto-detected.
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@item -strict strictness
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How strictly to follow the standards.
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@item -aic
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Enable Advanced intra coding (h263+).
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@item -umv
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Enable Unlimited Motion Vector (h263+)
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@item -deinterlace
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Deinterlace pictures.
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@item -interlace
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Force interlacing support in encoder (MPEG-2 and MPEG-4 only).
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Use this option if your input file is interlaced and you want
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to keep the interlaced format for minimum losses.
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The alternative is to deinterlace the input stream with
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@option{-deinterlace}, but deinterlacing introduces losses.
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@item -psnr
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Calculate PSNR of compressed frames.
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@item -vstats
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Dump video coding statistics to @file{vstats_HHMMSS.log}.
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@item -vhook module
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Insert video processing @var{module}. @var{module} contains the module
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name and its parameters separated by spaces.
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@end table
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@section Audio Options
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@table @option
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@item -ar freq
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Set the audio sampling frequency (default = 44100 Hz).
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@item -ab bitrate
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Set the audio bitrate in kbit/s (default = 64).
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@item -ac channels
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Set the number of audio channels (default = 1).
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@item -an
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Disable audio recording.
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@item -acodec codec
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Force audio codec to @var{codec}. Use the @code{copy} special value to
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specify that the raw codec data must be copied as is.
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@end table
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@section Audio/Video grab options
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@table @option
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@item -vd device
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sEt video grab device (e.g. @file{/dev/video0}).
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@item -vc channel
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Set video grab channel (DV1394 only).
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@item -tvstd standard
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Set television standard (NTSC, PAL (SECAM)).
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@item -dv1394
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Set DV1394 grab.
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@item -ad device
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Set audio device (e.g. @file{/dev/dsp}).
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@end table
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@section Advanced options
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@table @option
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@item -map file:stream
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Set input stream mapping.
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@item -debug
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Print specific debug info.
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@item -benchmark
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Add timings for benchmarking.
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@item -hex
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Dump each input packet.
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@item -bitexact
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Only use bit exact algorithms (for codec testing).
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@item -ps size
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Set packet size in bits.
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@item -re
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Read input at native frame rate. Mainly used to simulate a grab device.
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@item -loop
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Loop over the input stream. Currently it works only for image
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streams. This option is used for automatic FFserver testing.
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@item -loop_output number_of_times
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Repeatedly loop output for formats that support looping such as animated GIF
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(0 will loop the output infinitely).
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@end table
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@node FFmpeg formula evaluator
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@section FFmpeg formula evaluator
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When evaluating a rate control string, FFmpeg uses an internal formula
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evaluator.
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The following binary operators are available: @code{+}, @code{-},
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@code{*}, @code{/}, @code{^}.
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The following unary operators are available: @code{+}, @code{-},
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@code{(...)}.
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The following functions are available:
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@table @var
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@item sinh(x)
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@item cosh(x)
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@item tanh(x)
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@item sin(x)
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@item cos(x)
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@item tan(x)
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@item exp(x)
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@item log(x)
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@item squish(x)
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@item gauss(x)
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@item abs(x)
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@item max(x, y)
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@item min(x, y)
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@item gt(x, y)
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@item lt(x, y)
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@item eq(x, y)
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@item bits2qp(bits)
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@item qp2bits(qp)
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@end table
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The following constants are available:
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@table @var
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@item PI
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@item E
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@item iTex
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@item pTex
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@item tex
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@item mv
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@item fCode
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@item iCount
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@item mcVar
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@item var
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@item isI
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@item isP
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@item isB
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@item avgQP
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@item qComp
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@item avgIITex
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@item avgPITex
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@item avgPPTex
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@item avgBPTex
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@item avgTex
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@end table
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@c man end
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@ignore
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@setfilename ffmpeg
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@settitle FFmpeg video converter
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@c man begin SEEALSO
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ffserver(1), ffplay(1) and the HTML documentation of @file{ffmpeg}.
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@c man end
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@c man begin AUTHOR
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Fabrice Bellard
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@c man end
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@end ignore
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@section Protocols
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The filename can be @file{-} to read from standard input or to write
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to standard output.
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FFmpeg also handles many protocols specified with an URL syntax.
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Use 'ffmpeg -formats' to see a list of the supported protocols.
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The protocol @code{http:} is currently used only to communicate with
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FFserver (see the FFserver documentation). When FFmpeg will be a
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video player it will also be used for streaming :-)
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@chapter Tips
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@itemize
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@item For streaming at very low bitrate application, use a low frame rate
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and a small GOP size. This is especially true for RealVideo where
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the Linux player does not seem to be very fast, so it can miss
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frames. An example is:
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@example
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ffmpeg -g 3 -r 3 -t 10 -b 50 -s qcif -f rv10 /tmp/b.rm
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@end example
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@item  The parameter 'q' which is displayed while encoding is the current
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quantizer. The value 1 indicates that a very good quality could
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be achieved. The value 31 indicates the worst quality. If q=31 appears
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too often, it means that the encoder cannot compress enough to meet
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your bitrate. You must either increase the bitrate, decrease the
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frame rate or decrease the frame size.
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@item If your computer is not fast enough, you can speed up the
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compression at the expense of the compression ratio. You can use
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'-me zero' to speed up motion estimation, and '-intra' to disable
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motion estimation completely (you have only I-frames, which means it
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is about as good as JPEG compression).
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@item To have very low audio bitrates, reduce the sampling frequency
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(down to 22050 kHz for MPEG audio, 22050 or 11025 for AC3).
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@item To have a constant quality (but a variable bitrate), use the option
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'-qscale n' when 'n' is between 1 (excellent quality) and 31 (worst
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quality).
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@item When converting video files, you can use the '-sameq' option which
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uses the same quality factor in the encoder as in the decoder.
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It allows almost lossless encoding.
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@end itemize
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@chapter Supported File Formats and Codecs
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You can use the @code{-formats} option to have an exhaustive list.
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@section File Formats
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FFmpeg supports the following file formats through the @code{libavformat}
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library:
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@multitable @columnfractions .4 .1 .1 .4
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@item Supported File Format @tab Encoding @tab Decoding @tab Comments
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@item MPEG audio @tab X @tab X
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@item MPEG-1 systems @tab X  @tab  X
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@tab muxed audio and video
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@item MPEG-2 PS @tab X  @tab  X
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@tab also known as @code{VOB} file
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@item MPEG-2 TS @tab    @tab  X
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@tab also known as DVB Transport Stream
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@item ASF@tab X @tab X
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@item AVI@tab X @tab X
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@item WAV@tab X @tab X
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@item Macromedia Flash@tab X @tab X
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@tab Only embedded audio is decoded.
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@item FLV              @tab  X @tab X
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@tab Macromedia Flash video files
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@item Real Audio and Video @tab X @tab X
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@item Raw AC3 @tab X  @tab  X
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@item Raw MJPEG @tab X  @tab  X
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@item Raw MPEG video @tab X  @tab  X
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@item Raw PCM8/16 bits, mulaw/Alaw@tab X  @tab  X
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@item Raw CRI ADX audio @tab X  @tab  X
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@item Raw Shorten audio @tab    @tab  X
667
@item SUN AU format @tab X  @tab  X
668
@item NUT @tab X @tab X @tab NUT Open Container Format
669
@item QuickTime        @tab X @tab  X
670
@item MPEG-4           @tab X @tab  X
671
@tab MPEG-4 is a variant of QuickTime.
672
@item Raw MPEG4 video  @tab  X @tab  X
673
@item DV               @tab  X @tab  X
674
@item 4xm              @tab    @tab X
675
@tab 4X Technologies format, used in some games.
676
@item Playstation STR  @tab    @tab X
677
@item Id RoQ           @tab    @tab X
678
@tab Used in Quake III, Jedi Knight 2, other computer games.
679
@item Interplay MVE    @tab    @tab X
680
@tab Format used in various Interplay computer games.
681
@item WC3 Movie        @tab    @tab X
682
@tab Multimedia format used in Origin's Wing Commander III computer game.
683
@item Sega FILM/CPK    @tab    @tab X
684
@tab Used in many Sega Saturn console games.
685
@item Westwood Studios VQA/AUD  @tab    @tab X
686
@tab Multimedia formats used in Westwood Studios games.
687
@item Id Cinematic (.cin) @tab    @tab X
688
@tab Used in Quake II.
689
@item FLIC format      @tab    @tab X
690
@tab .fli/.flc files
691
@item Sierra VMD       @tab    @tab X
692
@tab Used in Sierra CD-ROM games.
693
@item Sierra Online    @tab    @tab X
694
@tab .sol files used in Sierra Online games.
695
@item Matroska         @tab    @tab X
696
@item Electronic Arts Multimedia    @tab    @tab X
697
@tab Used in various EA games; files have extensions like WVE and UV2.
698
@item Nullsoft Video (NSV) format @tab    @tab X
699
@item ADTS AAC audio @tab X @tab X
700
@item Creative VOC @tab X @tab X @tab Created for the Sound Blaster Pro.
701
@item American Laser Games MM  @tab    @tab X
702
@tab Multimedia format used in games like Mad Dog McCree
703
@item AVS @tab    @tab X
704
@tab Multimedia format used by the Creature Shock game.
705
@end multitable
706

    
707
@code{X} means that encoding (resp. decoding) is supported.
708

    
709
@section Image Formats
710

    
711
FFmpeg can read and write images for each frame of a video sequence. The
712
following image formats are supported:
713

    
714
@multitable @columnfractions .4 .1 .1 .4
715
@item Supported Image Format @tab Encoding @tab Decoding @tab Comments
716
@item PGM, PPM     @tab X @tab X
717
@item PAM          @tab X @tab X @tab PAM is a PNM extension with alpha support.
718
@item PGMYUV       @tab X @tab X @tab PGM with U and V components in YUV 4:2:0
719
@item JPEG         @tab X @tab X @tab Progressive JPEG is not supported.
720
@item .Y.U.V       @tab X @tab X @tab one raw file per component
721
@item animated GIF @tab X @tab X @tab Only uncompressed GIFs are generated.
722
@item PNG          @tab X @tab X @tab 2 bit and 4 bit/pixel not supported yet.
723
@item SGI          @tab X @tab X @tab SGI RGB image format
724
@end multitable
725

    
726
@code{X} means that encoding (resp. decoding) is supported.
727

    
728
@section Video Codecs
729

    
730
@multitable @columnfractions .4 .1 .1 .4
731
@item Supported Codec @tab Encoding @tab Decoding @tab Comments
732
@item MPEG-1 video           @tab  X  @tab  X
733
@item MPEG-2 video           @tab  X  @tab  X
734
@item MPEG-4                 @tab  X  @tab  X @tab also known as DivX4/5
735
@item MSMPEG4 V1             @tab  X  @tab  X
736
@item MSMPEG4 V2             @tab  X  @tab  X
737
@item MSMPEG4 V3             @tab  X  @tab  X @tab also known as DivX3
738
@item WMV7                   @tab  X  @tab  X
739
@item WMV8                   @tab  X  @tab  X @tab not completely working
740
@item H.261                  @tab  X  @tab  X
741
@item H.263(+)               @tab  X  @tab  X @tab also known as RealVideo 1.0
742
@item H.264                  @tab     @tab  X
743
@item RealVideo 1.0          @tab  X  @tab  X
744
@item RealVideo 2.0          @tab  X  @tab  X
745
@item MJPEG                  @tab  X  @tab  X
746
@item lossless MJPEG         @tab  X  @tab  X
747
@item Apple MJPEG-B          @tab     @tab  X
748
@item Sunplus MJPEG          @tab     @tab  X @tab fourcc: SP5X
749
@item DV                     @tab  X  @tab  X
750
@item HuffYUV                @tab  X  @tab  X
751
@item FFmpeg Video 1         @tab  X  @tab  X @tab experimental lossless codec (fourcc: FFV1)
752
@item FFmpeg Snow            @tab  X  @tab  X @tab experimental wavelet codec (fourcc: SNOW)
753
@item Asus v1                @tab  X  @tab  X @tab fourcc: ASV1
754
@item Asus v2                @tab  X  @tab  X @tab fourcc: ASV2
755
@item Creative YUV           @tab     @tab  X @tab fourcc: CYUV
756
@item Sorenson Video 1       @tab  X  @tab  X @tab fourcc: SVQ1
757
@item Sorenson Video 3       @tab     @tab  X @tab fourcc: SVQ3
758
@item On2 VP3                @tab     @tab  X @tab still experimental
759
@item Theora                 @tab     @tab  X @tab still experimental
760
@item Intel Indeo 3          @tab     @tab  X
761
@item FLV                    @tab  X  @tab  X @tab Sorenson H.263 used in Flash
762
@item ATI VCR1               @tab     @tab  X @tab fourcc: VCR1
763
@item ATI VCR2               @tab     @tab  X @tab fourcc: VCR2
764
@item Cirrus Logic AccuPak   @tab     @tab  X @tab fourcc: CLJR
765
@item 4X Video               @tab     @tab  X @tab Used in certain computer games.
766
@item Sony Playstation MDEC  @tab     @tab  X
767
@item Id RoQ                 @tab     @tab  X @tab Used in Quake III, Jedi Knight 2, other computer games.
768
@item Xan/WC3                @tab     @tab  X @tab Used in Wing Commander III .MVE files.
769
@item Interplay Video        @tab     @tab  X @tab Used in Interplay .MVE files.
770
@item Apple Animation        @tab     @tab  X @tab fourcc: 'rle '
771
@item Apple Graphics         @tab     @tab  X @tab fourcc: 'smc '
772
@item Apple Video            @tab     @tab  X @tab fourcc: rpza
773
@item Apple QuickDraw        @tab     @tab  X @tab fourcc: qdrw
774
@item Cinepak                @tab     @tab  X
775
@item Microsoft RLE          @tab     @tab  X
776
@item Microsoft Video-1      @tab     @tab  X
777
@item Westwood VQA           @tab     @tab  X
778
@item Id Cinematic Video     @tab     @tab  X @tab Used in Quake II.
779
@item Planar RGB             @tab     @tab  X @tab fourcc: 8BPS
780
@item FLIC video             @tab     @tab  X
781
@item Duck TrueMotion v1     @tab     @tab  X @tab fourcc: DUCK
782
@item Duck TrueMotion v2     @tab     @tab  X @tab fourcc: TM20
783
@item VMD Video              @tab     @tab  X @tab Used in Sierra VMD files.
784
@item MSZH                   @tab     @tab  X @tab Part of LCL
785
@item ZLIB                   @tab  X  @tab  X @tab Part of LCL, encoder experimental
786
@item TechSmith Camtasia     @tab     @tab  X @tab fourcc: TSCC
787
@item IBM Ultimotion         @tab     @tab  X @tab fourcc: ULTI
788
@item Miro VideoXL           @tab     @tab  X @tab fourcc: VIXL
789
@item QPEG                   @tab     @tab  X @tab fourccs: QPEG, Q1.0, Q1.1
790
@item LOCO                   @tab     @tab  X @tab
791
@item Winnov WNV1            @tab     @tab  X @tab
792
@item Autodesk Animator Studio Codec  @tab     @tab  X @tab fourcc: AASC
793
@item Fraps FPS1             @tab     @tab  X @tab
794
@item CamStudio              @tab     @tab  X @tab fourcc: CSCD
795
@item American Laser Games Video  @tab    @tab X @tab Used in games like Mad Dog McCree
796
@item ZMBV                   @tab     @tab  X @tab
797
@item AVS Video              @tab     @tab  X @tab Video encoding used by the Creature Shock game.
798
@end multitable
799

    
800
@code{X} means that encoding (resp. decoding) is supported.
801

    
802
See @url{http://mplayerhq.hu/~michael/codec-features.html} to
803
get a precise comparison of the FFmpeg MPEG-4 codec compared to
804
other implementations.
805

    
806
@section Audio Codecs
807

    
808
@multitable @columnfractions .4 .1 .1 .1 .7
809
@item Supported Codec @tab Encoding @tab Decoding @tab Comments
810
@item MPEG audio layer 2     @tab  IX  @tab  IX
811
@item MPEG audio layer 1/3   @tab IX   @tab  IX
812
@tab MP3 encoding is supported through the external library LAME.
813
@item AC3                    @tab  IX  @tab  IX
814
@tab liba52 is used internally for decoding.
815
@item Vorbis                 @tab  X   @tab  X
816
@tab Supported through the external library libvorbis.
817
@item WMA V1/V2              @tab      @tab X
818
@item AAC                    @tab X    @tab X
819
@tab Supported through the external library libfaac/libfaad.
820
@item Microsoft ADPCM        @tab X    @tab X
821
@item MS IMA ADPCM           @tab X    @tab X
822
@item QT IMA ADPCM           @tab      @tab X
823
@item 4X IMA ADPCM           @tab      @tab X
824
@item G.726  ADPCM           @tab X    @tab X
825
@item Duck DK3 IMA ADPCM     @tab      @tab X
826
@tab Used in some Sega Saturn console games.
827
@item Duck DK4 IMA ADPCM     @tab      @tab X
828
@tab Used in some Sega Saturn console games.
829
@item Westwood Studios IMA ADPCM @tab      @tab X
830
@tab Used in Westwood Studios games like Command and Conquer.
831
@item SMJPEG IMA ADPCM       @tab      @tab X
832
@tab Used in certain Loki game ports.
833
@item CD-ROM XA ADPCM        @tab      @tab X
834
@item CRI ADX ADPCM          @tab X    @tab X
835
@tab Used in Sega Dreamcast games.
836
@item Electronic Arts ADPCM  @tab      @tab X
837
@tab Used in various EA titles.
838
@item Creative ADPCM         @tab      @tab X
839
@tab 16 -> 4, 8 -> 4, 8 -> 3, 8 -> 2
840
@item RA144                  @tab      @tab X
841
@tab Real 14400 bit/s codec
842
@item RA288                  @tab      @tab X
843
@tab Real 28800 bit/s codec
844
@item RADnet                 @tab X    @tab IX
845
@tab Real low bitrate AC3 codec, liba52 is used for decoding.
846
@item AMR-NB                 @tab X    @tab X
847
@tab Supported through an external library.
848
@item AMR-WB                 @tab X    @tab X
849
@tab Supported through an external library.
850
@item DV audio               @tab      @tab X
851
@item Id RoQ DPCM            @tab      @tab X
852
@tab Used in Quake III, Jedi Knight 2, other computer games.
853
@item Interplay MVE DPCM     @tab      @tab X
854
@tab Used in various Interplay computer games.
855
@item Xan DPCM               @tab      @tab X
856
@tab Used in Origin's Wing Commander IV AVI files.
857
@item Sierra Online DPCM     @tab      @tab X
858
@tab Used in Sierra Online game audio files.
859
@item Apple MACE 3           @tab      @tab X
860
@item Apple MACE 6           @tab      @tab X
861
@item FLAC lossless audio    @tab      @tab X
862
@item Shorten lossless audio @tab      @tab X
863
@item Apple lossless audio   @tab      @tab X
864
@tab QuickTime fourcc 'alac'
865
@item FFmpeg Sonic           @tab X    @tab X
866
@tab experimental lossy/lossless codec
867
@item Qdesign QDM2           @tab      @tab X
868
@tab there are still some distortions
869
@item Real COOK              @tab      @tab X
870
@tab All versions except 5.1 are supported
871
@item DSP Group TrueSpeech   @tab      @tab X
872
@item True Audio (TTA)       @tab      @tab X
873
@end multitable
874

    
875
@code{X} means that encoding (resp. decoding) is supported.
876

    
877
@code{I} means that an integer-only version is available, too (ensures high
878
performance on systems without hardware floating point support).
879

    
880
@chapter Platform Specific information
881

    
882
@section Linux
883

    
884
FFmpeg should be compiled with at least GCC 2.95.3. GCC 3.2 is the
885
preferred compiler now for FFmpeg. All future optimizations will depend on
886
features only found in GCC 3.2.
887

    
888
@section BSD
889

    
890
BSD make will not build FFmpeg, you need to install and use GNU Make
891
(@file{gmake}).
892

    
893
@section Windows
894

    
895
@subsection Native Windows compilation
896

    
897
@itemize
898
@item Install the current versions of MSYS and MinGW from
899
@url{http://www.mingw.org/}. You can find detailed installation
900
instructions in the download section and the FAQ.
901

    
902
@item If you want to test the FFplay, also download
903
the MinGW development library of SDL 1.2.x
904
(@file{SDL-devel-1.2.x-mingw32.tar.gz}) from
905
@url{http://www.libsdl.org}. Unpack it in a temporary directory, and
906
unpack the archive @file{i386-mingw32msvc.tar.gz} in the MinGW tool
907
directory. Edit the @file{sdl-config} script so that it gives the
908
correct SDL directory when invoked.
909

    
910
@item Extract the current version of FFmpeg.
911

    
912
@item Start the MSYS shell (file @file{msys.bat}).
913

    
914
@item Change to the FFmpeg directory and follow
915
 the instructions of how to compile FFmpeg (file
916
@file{INSTALL}). Usually, launching @file{./configure} and @file{make}
917
suffices. If you have problems using SDL, verify that
918
@file{sdl-config} can be launched from the MSYS command line.
919

    
920
@item You can install FFmpeg in @file{Program Files/FFmpeg} by typing
921
@file{make install}. Don't forget to copy @file{SDL.dll} to the place
922
you launch @file{ffplay} from.
923

    
924
@end itemize
925

    
926
Notes:
927
@itemize
928

    
929
@item The target @file{make wininstaller} can be used to create a
930
Nullsoft based Windows installer for FFmpeg and FFplay. @file{SDL.dll}
931
must be copied to the FFmpeg directory in order to build the
932
installer.
933

    
934
@item By using @code{./configure --enable-shared} when configuring FFmpeg,
935
you can build @file{avcodec.dll} and @file{avformat.dll}. With
936
@code{make install} you install the FFmpeg DLLs and the associated
937
headers in @file{Program Files/FFmpeg}.
938

    
939
@item Visual C++ compatibility: If you used @code{./configure --enable-shared}
940
when configuring FFmpeg, FFmpeg tries to use the Microsoft Visual
941
C++ @code{lib} tool to build @code{avcodec.lib} and
942
@code{avformat.lib}. With these libraries you can link your Visual C++
943
code directly with the FFmpeg DLLs (see below).
944

    
945
@end itemize
946

    
947
@subsection Visual C++ compatibility
948

    
949
FFmpeg will not compile under Visual C++ -- and it has too many
950
dependencies on the GCC compiler to make a port viable. However,
951
if you want to use the FFmpeg libraries in your own applications,
952
you can still compile those applications using Visual C++. An
953
important restriction to this is that you have to use the
954
dynamically linked versions of the FFmpeg libraries (i.e. the
955
DLLs), and you have to make sure that Visual-C++-compatible
956
import libraries are created during the FFmpeg build process.
957

    
958
This description of how to use the FFmpeg libraries with Visual C++ is
959
based on Visual C++ 2005 Express Edition Beta 2. If you have a different
960
version, you might have to modify the procedures slightly.
961

    
962
Here are the step-by-step instructions for building the FFmpeg libraries
963
so they can be used with Visual C++:
964

    
965
@enumerate
966

    
967
@item Install Visual C++ (if you haven't done so already).
968

    
969
@item Install MinGW and MSYS as described above.
970

    
971
@item Add a call to @file{vcvars32.bat} (which sets up the environment
972
variables for the Visual C++ tools) as the first line of
973
@file{msys.bat}. The standard location for @file{vcvars32.bat} is
974
@file{C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat},
975
and the standard location for @file{msys.bat} is
976
@file{C:\msys\1.0\msys.bat}. If this corresponds to your setup, add the
977
following line as the first line of @file{msys.bat}:
978

    
979
@code{call "C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat"}
980

    
981
@item Start the MSYS shell (file @file{msys.bat}) and type @code{link.exe}.
982
If you get a help message with the command line options of @code{link.exe},
983
this means your environment variables are set up correctly, the
984
Microsoft linker is on the path and will be used by FFmpeg to
985
create Visual-C++-compatible import libraries.
986

    
987
@item Extract the current version of FFmpeg and change to the FFmpeg directory.
988

    
989
@item Type the command
990
@code{./configure --enable-shared --disable-static --enable-memalign-hack}
991
to configure and, if that didn't produce any errors,
992
type @code{make} to build FFmpeg.
993

    
994
@item The subdirectories @file{libavformat}, @file{libavcodec}, and
995
@file{libavutil} should now contain the files @file{avformat.dll},
996
@file{avformat.lib}, @file{avcodec.dll}, @file{avcodec.lib},
997
@file{avutil.dll}, and @file{avutil.lib}, respectively. Copy the three
998
DLLs to your System32 directory (typically @file{C:\Windows\System32}).
999

    
1000
@end enumerate
1001

    
1002
And here is how to use these libraries with Visual C++:
1003

    
1004
@enumerate
1005

    
1006
@item Create a new console application ("File / New / Project") and then
1007
select "Win32 Console Application". On the appropriate page of the
1008
Application Wizard, uncheck the "Precompiled headers" option.
1009

    
1010
@item Write the source code for your application, or, for testing, just
1011
copy the code from an existing sample application into the source file
1012
that Visual C++ has already created for you. (Note that your source
1013
filehas to have a @code{.cpp} extension; otherwise, Visual C++ won't
1014
compile the FFmpeg headers correctly because in C mode, it doesn't
1015
recognize the @code{inline} keyword.)  For example, you can copy
1016
@file{output_example.c} from the FFmpeg distribution (but you will
1017
have to make minor modifications so the code will compile under
1018
C++, see below).
1019

    
1020
@item Open the "Project / Properties" dialog box. In the "Configuration"
1021
combo box, select "All Configurations" so that the changes you make will
1022
affect both debug and release builds. In the tree view on the left hand
1023
side, select "C/C++ / General", then edit the "Additional Include
1024
Directories" setting to contain the complete paths to the
1025
@file{libavformat}, @file{libavcodec}, and @file{libavutil}
1026
subdirectories of your FFmpeg directory. Note that the directories have
1027
to be separated using semicolons. Now select "Linker / General" from the
1028
tree view and edit the "Additional Library Directories" setting to
1029
contain the same three directories.
1030

    
1031
@item Still in the "Project / Properties" dialog box, select "Linker / Input"
1032
from the tree view, then add the files @file{avformat.lib},
1033
@file{avcodec.lib}, and @file{avutil.lib} to the end of the "Additional
1034
Dependencies". Note that the names of the libraries have to be separated
1035
using spaces.
1036

    
1037
@item Now, select "C/C++ / Code Generation" from the tree view. Select
1038
"Debug" in the "Configuration" combo box. Make sure that "Runtime
1039
Library" is set to "Multi-threaded Debug DLL". Then, select "Release" in
1040
the "Configuration" combo box and make sure that "Runtime Library" is
1041
set to "Multi-threaded DLL".
1042

    
1043
@item Click "OK" to close the "Project / Properties" dialog box and build
1044
the application. Hopefully, it should compile and run cleanly. If you
1045
used @file{output_example.c} as your sample application, you will get a
1046
few compiler errors, but they are easy to fix. The first type of error
1047
occurs because Visual C++ doesn't allow an @code{int} to be converted to
1048
an @code{enum} without a cast. To solve the problem, insert the required
1049
casts (this error occurs once for a @code{CodecID} and once for a
1050
@code{CodecType}).  The second type of error occurs because C++ requires
1051
the return value of @code{malloc} to be cast to the exact type of the
1052
pointer it is being assigned to. Visual C++ will complain that, for
1053
example, @code{(void *)} is being assigned to @code{(uint8_t *)} without
1054
an explicit cast. So insert an explicit cast in these places to silence
1055
the compiler. The third type of error occurs because the @code{snprintf}
1056
library function is called @code{_snprintf} under Visual C++.  So just
1057
add an underscore to fix the problem. With these changes,
1058
@file{output_example.c} should compile under Visual C++, and the
1059
resulting executable should produce valid video files.
1060

    
1061
@end enumerate
1062

    
1063
@subsection Cross compilation for Windows with Linux
1064

    
1065
You must use the MinGW cross compilation tools available at
1066
@url{http://www.mingw.org/}.
1067

    
1068
Then configure FFmpeg with the following options:
1069
@example
1070
./configure --enable-mingw32 --cross-prefix=i386-mingw32msvc-
1071
@end example
1072
(you can change the cross-prefix according to the prefix chosen for the
1073
MinGW tools).
1074

    
1075
Then you can easily test FFmpeg with Wine
1076
(@url{http://www.winehq.com/}).
1077

    
1078
@section Mac OS X
1079

    
1080
@section BeOS
1081

    
1082
The configure script should guess the configuration itself.
1083
Networking support is currently not finished.
1084
errno issues fixed by Andrew Bachmann.
1085

    
1086
Old stuff:
1087

    
1088
Fran├žois Revol - revol at free dot fr - April 2002
1089

    
1090
The configure script should guess the configuration itself,
1091
however I still didn't test building on the net_server version of BeOS.
1092

    
1093
FFserver is broken (needs poll() implementation).
1094

    
1095
There are still issues with errno codes, which are negative in BeOS, and
1096
that FFmpeg negates when returning. This ends up turning errors into
1097
valid results, then crashes.
1098
(To be fixed)
1099

    
1100
@chapter Developers Guide
1101

    
1102
@section API
1103
@itemize
1104
@item libavcodec is the library containing the codecs (both encoding and
1105
decoding). Look at @file{libavcodec/apiexample.c} to see how to use it.
1106

    
1107
@item libavformat is the library containing the file format handling (mux and
1108
demux code for several formats). Look at @file{ffplay.c} to use it in a
1109
player. See @file{output_example.c} to use it to generate audio or video
1110
streams.
1111

    
1112
@end itemize
1113

    
1114
@section Integrating libavcodec or libavformat in your program
1115

    
1116
You can integrate all the source code of the libraries to link them
1117
statically to avoid any version problem. All you need is to provide a
1118
'config.mak' and a 'config.h' in the parent directory. See the defines
1119
generated by ./configure to understand what is needed.
1120

    
1121
You can use libavcodec or libavformat in your commercial program, but
1122
@emph{any patch you make must be published}. The best way to proceed is
1123
to send your patches to the FFmpeg mailing list.
1124

    
1125
@node Coding Rules
1126
@section Coding Rules
1127

    
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FFmpeg is programmed in the ISO C90 language with a few additional
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features from ISO C99, namely:
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@itemize @bullet
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@item
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the @samp{inline} keyword;
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@item
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@samp{//} comments;
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@item
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designated struct initializers (@samp{struct s x = @{ .i = 17 @};})
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@item
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compound literals (@samp{x = (struct s) @{ 17, 23 @};})
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@end itemize
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These features are supported by all compilers we care about, so we won't
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accept patches to remove their use unless they absolutely don't impair
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clarity and performance.
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All code must compile with GCC 2.95 and GCC 3.3. Currently, FFmpeg also
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compiles with several other compilers, such as the Compaq ccc compiler
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or Sun Studio 9, and we would like to keep it that way unless it would
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be exceedingly involved. To ensure compatibility, please don't use any
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additional C99 features or GCC extensions. Especially watch out for:
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@itemize @bullet
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@item
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mixing statements and declarations;
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@item
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@samp{long long} (use @samp{int64_t} instead);
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@item
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@samp{__attribute__} not protected by @samp{#ifdef __GNUC__} or similar;
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@item
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GCC statement expressions (@samp{(x = (@{ int y = 4; y; @})}).
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@end itemize
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Indent size is 4.
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The presentation is the one specified by 'indent -i4 -kr -nut'.
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The TAB character is forbidden outside of Makefiles as is any
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form of trailing whitespace. Commits containing either will be
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rejected by the CVS repository.
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Main priority in FFmpeg is simplicity and small code size (=less
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bugs).
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Comments: Use the JavaDoc/Doxygen
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format (see examples below) so that code documentation
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can be generated automatically. All nontrivial functions should have a comment
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above them explaining what the function does, even if it's just one sentence.
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All structures and their member variables should be documented, too.
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@example
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/**
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 * @@file mpeg.c
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 * MPEG codec.
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 * @@author ...
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 */
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/**
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 * Summary sentence.
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 * more text ...
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 * ...
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 */
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typedef struct Foobar@{
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    int var1; /**< var1 description */
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    int var2; ///< var2 description
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    /** var3 description */
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    int var3;
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@} Foobar;
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/**
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 * Summary sentence.
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 * more text ...
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 * ...
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 * @@param my_parameter description of my_parameter
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 * @@return return value description
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 */
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int myfunc(int my_parameter)
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...
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@end example
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fprintf and printf are forbidden in libavformat and libavcodec,
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please use av_log() instead.
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@node CVS Policy
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@section CVS Policy
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@enumerate
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@item
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   You must not commit code which breaks FFmpeg! (Meaning unfinished but
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   enabled code which breaks compilation or compiles but does not work or
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   breaks the regression tests)
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   You can commit unfinished stuff (for testing etc), but it must be disabled
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   (#ifdef etc) by default so it does not interfere with other developers'
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   work.
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@item
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   You don't have to over-test things. If it works for you, and you think it
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   should work for others, then commit. If your code has problems
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   (portability, triggers compiler bugs, unusual environment etc) they will be
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   reported and eventually fixed.
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@item
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   Do not commit unrelated changes together, split them into self-contained
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   pieces.
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@item
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   Do not change behavior of the program (renaming options etc) without
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   first discussing it on the ffmpeg-devel mailing list. Do not remove
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   functionality from the code. Just improve!
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   Note: Redundant code can be removed.
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@item
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   Do not commit changes to the build system (Makefiles, configure script)
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   which change behavior, defaults etc, without asking first. The same
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   applies to compiler warning fixes, trivial looking fixes and to code
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   maintained by other developers. We usually have a reason for doing things
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   the way we do. Send your changes as patches to the ffmpeg-devel mailing
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   list, and if the code maintainers say OK, you may commit. This does not
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   apply to files you wrote and/or maintain.
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@item
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   We refuse source indentation and other cosmetic changes if they are mixed
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   with functional changes, such commits will be rejected and removed. Every
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   developer has his own indentation style, you should not change it. Of course
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   if you (re)write something, you can use your own style, even though we would
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   prefer if the indentation throughout FFmpeg was consistent (Many projects
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   force a given indentation style - we don't.). If you really need to make
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   indentation changes (try to avoid this), separate them strictly from real
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   changes.
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   NOTE: If you had to put if()@{ .. @} over a large (> 5 lines) chunk of code,
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   then either do NOT change the indentation of the inner part within (don't
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   move it to the right)! or do so in a separate commit
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@item
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   Always fill out the commit log message. Describe in a few lines what you
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   changed and why. You can refer to mailing list postings if you fix a
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   particular bug. Comments such as "fixed!" or "Changed it." are unacceptable.
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@item
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   If you apply a patch by someone else, include the name and email address in
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   the CVS log message. Since the ffmpeg-cvslog mailing list is publicly
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   archived you should add some SPAM protection to the email address. Send an
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   answer to ffmpeg-devel (or wherever you got the patch from) saying that
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   you applied the patch.
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@item
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   Do NOT commit to code actively maintained by others without permission. Send
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   a patch to ffmpeg-devel instead.
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@item
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    Subscribe to the ffmpeg-cvslog mailing list. The diffs of all CVS commits
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    are sent there and reviewed by all the other developers. Bugs and possible
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    improvements or general questions regarding commits are discussed there. We
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    expect you to react if problems with your code are uncovered.
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@item
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    Update the documentation if you change behavior or add features. If you are
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    unsure how best to do this, send a patch to ffmpeg-devel, the documentation
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    maintainer(s) will review and commit your stuff.
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@item
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    Revert a commit ONLY in case of a big blunder like committing something not
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    intended to be committed or committing a wrong file, the wrong version of a
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    patch, CVS policy violation or broken code and you are going to recommit the
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    right thing immediately.
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    Never revert changes made a long time ago or buggy code. Fix it in the
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    normal way instead.
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@item
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    Never write to unallocated memory, never write over the end of arrays,
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    always check values read from some untrusted source before using them
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    as array index or other risky things.
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@item
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    Remember to check if you need to bump versions for the specific libav
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    parts (libavutil, libavcodec, libavformat) you are changing. You need
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    to change the version integer and the version string.
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    Incrementing the first component means no backward compatibility to
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    previous versions (e.g. removal of a function).
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    Incrementing the second component means backward compatible change
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    (e.g. addition of a function).
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    Incrementing the third component means a noteworthy binary compatible
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    change (e.g. encoder bug fix that matters for the decoder).
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@item
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    If you add a new codec, remember to update the changelog, add it to
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    the supported codecs table in the documentation and bump the second
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    component of the @file{libavcodec} version number appropriately. If
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    it has a fourcc, add it to @file{libavformat/avienc.c}, even if it
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    is only a decoder.
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@end enumerate
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We think our rules are not too hard. If you have comments, contact us.
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Note, these rules are mostly borrowed from the MPlayer project.
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@subsection Renaming/moving files or content of files
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  You CANNOT do that. Post a request for such a change to the mailing list
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  Do NOT remove & readd a file - it will kill the changelog!!!!
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@section Submitting patches
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First, (@pxref{Coding Rules}) above if you didn't yet.
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When you submit your patch, try to send a unified diff (diff '-up'
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option). I cannot read other diffs :-)
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Also please do not submit patches which contain several unrelated changes.
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Split them into individual self-contained patches; this makes reviewing
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them much easier.
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Run the regression tests before submitting a patch so that you can
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verify that there are no big problems.
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Patches should be posted as base64 encoded attachments (or any other
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encoding which ensures that the patch won't be trashed during
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transmission) to the ffmpeg-devel mailing list, see
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@url{http://www1.mplayerhq.hu/mailman/listinfo/ffmpeg-devel}
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It also helps quite a bit if you tell us what the patch does (for example
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'replaces lrint by lrintf'), and why (for example '*BSD isn't C99 compliant
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and has no lrint()')
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We reply to all submitted patches and either apply or reject with some
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explanation why, but sometimes we are quite busy so it can take a week or two.
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@section Regression tests
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Before submitting a patch (or committing to CVS), you should at least
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test that you did not break anything.
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The regression tests build a synthetic video stream and a synthetic
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audio stream. These are then encoded and decoded with all codecs or
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formats. The CRC (or MD5) of each generated file is recorded in a
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result file. A 'diff' is launched to compare the reference results and
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the result file.
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The regression tests then go on to test the FFserver code with a
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limited set of streams. It is important that this step runs correctly
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as well.
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Run 'make test' to test all the codecs and formats.
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Run 'make fulltest' to test all the codecs, formats and FFserver.
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[Of course, some patches may change the results of the regression tests. In
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this case, the reference results of the regression tests shall be modified
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accordingly].
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@bye