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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 
665
@item Raw CRI ADX audio @tab X  @tab  X 
666
@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
@end multitable
700

    
701
@code{X} means that encoding (resp. decoding) is supported.
702

    
703
@section Image Formats
704

    
705
FFmpeg can read and write images for each frame of a video sequence. The
706
following image formats are supported:
707

    
708
@multitable @columnfractions .4 .1 .1 .4
709
@item Supported Image Format @tab Encoding @tab Decoding @tab Comments
710
@item PGM, PPM     @tab X @tab X 
711
@item PAM          @tab X @tab X @tab PAM is a PNM extension with alpha support.
712
@item PGMYUV       @tab X @tab X @tab PGM with U and V components in YUV 4:2:0
713
@item JPEG         @tab X @tab X @tab Progressive JPEG is not supported.
714
@item .Y.U.V       @tab X @tab X @tab one raw file per component
715
@item animated GIF @tab X @tab X @tab Only uncompressed GIFs are generated.
716
@item PNG          @tab X @tab X @tab 2 bit and 4 bit/pixel not supported yet.
717
@item SGI          @tab X @tab X @tab SGI RGB image format
718
@end multitable
719

    
720
@code{X} means that encoding (resp. decoding) is supported.
721

    
722
@section Video Codecs
723

    
724
@multitable @columnfractions .4 .1 .1 .4
725
@item Supported Codec @tab Encoding @tab Decoding @tab Comments
726
@item MPEG-1 video           @tab  X  @tab  X
727
@item MPEG-2 video           @tab  X  @tab  X
728
@item MPEG-4                 @tab  X  @tab  X @tab also known as DivX4/5
729
@item MSMPEG4 V1             @tab  X  @tab  X
730
@item MSMPEG4 V2             @tab  X  @tab  X
731
@item MSMPEG4 V3             @tab  X  @tab  X @tab also known as DivX3
732
@item WMV7                   @tab  X  @tab  X
733
@item WMV8                   @tab  X  @tab  X @tab not completely working
734
@item H.261                  @tab  X  @tab  X
735
@item H.263(+)               @tab  X  @tab  X @tab also known as RealVideo 1.0
736
@item H.264                  @tab     @tab  X
737
@item MJPEG                  @tab  X  @tab  X 
738
@item lossless MJPEG         @tab  X  @tab  X
739
@item Apple MJPEG-B          @tab     @tab  X
740
@item Sunplus MJPEG          @tab     @tab  X @tab fourcc: SP5X
741
@item DV                     @tab  X  @tab  X 
742
@item HuffYUV                @tab  X  @tab  X
743
@item FFmpeg Video 1         @tab  X  @tab  X @tab experimental lossless codec (fourcc: FFV1)
744
@item FFmpeg Snow            @tab  X  @tab  X @tab experimental wavelet codec (fourcc: SNOW)
745
@item Asus v1                @tab  X  @tab  X @tab fourcc: ASV1
746
@item Asus v2                @tab  X  @tab  X @tab fourcc: ASV2
747
@item Creative YUV           @tab     @tab  X @tab fourcc: CYUV
748
@item Sorenson Video 1       @tab  X  @tab  X @tab fourcc: SVQ1
749
@item Sorenson Video 3       @tab     @tab  X @tab fourcc: SVQ3
750
@item On2 VP3                @tab     @tab  X @tab still experimental
751
@item Theora                 @tab     @tab  X @tab still experimental
752
@item Intel Indeo 3          @tab     @tab  X
753
@item FLV                    @tab  X  @tab  X @tab Sorenson H.263 used in Flash
754
@item ATI VCR1               @tab     @tab  X @tab fourcc: VCR1
755
@item ATI VCR2               @tab     @tab  X @tab fourcc: VCR2
756
@item Cirrus Logic AccuPak   @tab     @tab  X @tab fourcc: CLJR
757
@item 4X Video               @tab     @tab  X @tab Used in certain computer games.
758
@item Sony Playstation MDEC  @tab     @tab  X 
759
@item Id RoQ                 @tab     @tab  X @tab Used in Quake III, Jedi Knight 2, other computer games.
760
@item Xan/WC3                @tab     @tab  X @tab Used in Wing Commander III .MVE files.
761
@item Interplay Video        @tab     @tab  X @tab Used in Interplay .MVE files.
762
@item Apple Animation        @tab     @tab  X @tab fourcc: 'rle '
763
@item Apple Graphics         @tab     @tab  X @tab fourcc: 'smc '
764
@item Apple Video            @tab     @tab  X @tab fourcc: rpza
765
@item Apple QuickDraw        @tab     @tab  X @tab fourcc: qdrw
766
@item Cinepak                @tab     @tab  X
767
@item Microsoft RLE          @tab     @tab  X
768
@item Microsoft Video-1      @tab     @tab  X
769
@item Westwood VQA           @tab     @tab  X
770
@item Id Cinematic Video     @tab     @tab  X @tab Used in Quake II.
771
@item Planar RGB             @tab     @tab  X @tab fourcc: 8BPS
772
@item FLIC video             @tab     @tab  X
773
@item Duck TrueMotion v1     @tab     @tab  X @tab fourcc: DUCK
774
@item Duck TrueMotion v2     @tab     @tab  X @tab fourcc: TM20
775
@item VMD Video              @tab     @tab  X @tab Used in Sierra VMD files.
776
@item MSZH                   @tab     @tab  X @tab Part of LCL
777
@item ZLIB                   @tab  X  @tab  X @tab Part of LCL, encoder experimental
778
@item TechSmith Camtasia     @tab     @tab  X @tab fourcc: TSCC
779
@item IBM Ultimotion         @tab     @tab  X @tab fourcc: ULTI
780
@item Miro VideoXL           @tab     @tab  X @tab fourcc: VIXL
781
@item QPEG                   @tab     @tab  X @tab fourccs: QPEG, Q1.0, Q1.1
782
@item LOCO                   @tab     @tab  X @tab 
783
@item Winnov WNV1            @tab     @tab  X @tab 
784
@item Autodesk Animator Studio Codec  @tab     @tab  X @tab fourcc: AASC
785
@item Fraps FPS1             @tab     @tab  X @tab 
786
@end multitable
787

    
788
@code{X} means that encoding (resp. decoding) is supported.
789

    
790
See @url{http://www.mplayerhq.hu/~michael/codec-features.html} to
791
get a precise comparison of the FFmpeg MPEG-4 codec compared to
792
other implementations.
793

    
794
@section Audio Codecs
795

    
796
@multitable @columnfractions .4 .1 .1 .1 .7
797
@item Supported Codec @tab Encoding @tab Decoding @tab Comments
798
@item MPEG audio layer 2     @tab  IX  @tab  IX 
799
@item MPEG audio layer 1/3   @tab IX   @tab  IX
800
@tab MP3 encoding is supported through the external library LAME.
801
@item AC3                    @tab  IX  @tab  IX
802
@tab liba52 is used internally for decoding.
803
@item Vorbis                 @tab  X   @tab  X
804
@tab Supported through the external library libvorbis.
805
@item WMA V1/V2              @tab      @tab X
806
@item AAC                    @tab X    @tab X
807
@tab Supported through the external library libfaac/libfaad.
808
@item Microsoft ADPCM        @tab X    @tab X
809
@item MS IMA ADPCM           @tab X    @tab X
810
@item QT IMA ADPCM           @tab      @tab X
811
@item 4X IMA ADPCM           @tab      @tab X
812
@item G.726  ADPCM           @tab X    @tab X
813
@item Duck DK3 IMA ADPCM     @tab      @tab X
814
@tab Used in some Sega Saturn console games.
815
@item Duck DK4 IMA ADPCM     @tab      @tab X
816
@tab Used in some Sega Saturn console games.
817
@item Westwood Studios IMA ADPCM @tab      @tab X
818
@tab Used in Westwood Studios games like Command and Conquer.
819
@item SMJPEG IMA ADPCM       @tab      @tab X
820
@tab Used in certain Loki game ports.
821
@item CD-ROM XA ADPCM        @tab      @tab X
822
@item CRI ADX ADPCM          @tab X    @tab X
823
@tab Used in Sega Dreamcast games.
824
@item Electronic Arts ADPCM  @tab      @tab X
825
@tab Used in various EA titles.
826
@item Creative ADPCM         @tab      @tab X
827
@item RA144                  @tab      @tab X
828
@tab Real 14400 bit/s codec
829
@item RA288                  @tab      @tab X
830
@tab Real 28800 bit/s codec
831
@item RADnet                 @tab X    @tab IX
832
@tab Real low bitrate AC3 codec, liba52 is used for decoding.
833
@item AMR-NB                 @tab X    @tab X
834
@tab Supported through an external library.
835
@item AMR-WB                 @tab X    @tab X
836
@tab Supported through an external library.
837
@item DV audio               @tab      @tab X
838
@item Id RoQ DPCM            @tab      @tab X
839
@tab Used in Quake III, Jedi Knight 2, other computer games.
840
@item Interplay MVE DPCM     @tab      @tab X
841
@tab Used in various Interplay computer games.
842
@item Xan DPCM               @tab      @tab X
843
@tab Used in Origin's Wing Commander IV AVI files.
844
@item Sierra Online DPCM     @tab      @tab X
845
@tab Used in Sierra Online game audio files.
846
@item Apple MACE 3           @tab      @tab X
847
@item Apple MACE 6           @tab      @tab X
848
@item FLAC lossless audio    @tab      @tab X
849
@item Shorten lossless audio @tab      @tab X
850
@item Apple lossless audio   @tab      @tab X
851
@tab QuickTime fourcc 'alac'
852
@item FFmpeg Sonic           @tab X    @tab X
853
@tab experimental lossy/lossless codec
854
@item Qdesign QDM2           @tab      @tab X
855
@tab there are still some distortions
856
@end multitable
857

    
858
@code{X} means that encoding (resp. decoding) is supported.
859

    
860
@code{I} means that an integer-only version is available, too (ensures high
861
performance on systems without hardware floating point support).
862

    
863
@chapter Platform Specific information
864

    
865
@section Linux
866

    
867
FFmpeg should be compiled with at least GCC 2.95.3. GCC 3.2 is the
868
preferred compiler now for FFmpeg. All future optimizations will depend on
869
features only found in GCC 3.2.
870

    
871
@section BSD
872

    
873
@section Windows
874

    
875
@subsection Native Windows compilation
876

    
877
@itemize
878
@item Install the current versions of MSYS and MinGW from
879
@url{http://www.mingw.org/}. You can find detailed installation
880
instructions in the download section and the FAQ.
881

    
882
@item If you want to test the FFplay, also download
883
the MinGW development library of SDL 1.2.x
884
(@file{SDL-devel-1.2.x-mingw32.tar.gz}) from
885
@url{http://www.libsdl.org}. Unpack it in a temporary directory, and
886
unpack the archive @file{i386-mingw32msvc.tar.gz} in the MinGW tool
887
directory. Edit the @file{sdl-config} script so that it gives the
888
correct SDL directory when invoked.
889

    
890
@item Extract the current version of FFmpeg.
891
 
892
@item Start the MSYS shell (file @file{msys.bat}).
893

    
894
@item Change to the FFmpeg directory and follow
895
 the instructions of how to compile FFmpeg (file
896
@file{INSTALL}). Usually, launching @file{./configure} and @file{make}
897
suffices. If you have problems using SDL, verify that
898
@file{sdl-config} can be launched from the MSYS command line.
899

    
900
@item You can install FFmpeg in @file{Program Files/FFmpeg} by typing
901
@file{make install}. Don't forget to copy @file{SDL.dll} to the place
902
you launch @file{ffplay} from.
903

    
904
@end itemize
905

    
906
Notes: 
907
@itemize
908

    
909
@item The target @file{make wininstaller} can be used to create a
910
Nullsoft based Windows installer for FFmpeg and FFplay. @file{SDL.dll}
911
must be copied to the FFmpeg directory in order to build the
912
installer.
913

    
914
@item By using @code{./configure --enable-shared} when configuring FFmpeg,
915
you can build @file{avcodec.dll} and @file{avformat.dll}. With
916
@code{make install} you install the FFmpeg DLLs and the associated
917
headers in @file{Program Files/FFmpeg}. 
918

    
919
@item Visual C++ compatibility: If you used @code{./configure --enable-shared}
920
when configuring FFmpeg, FFmpeg tries to use the Microsoft Visual
921
C++ @code{lib} tool to build @code{avcodec.lib} and
922
@code{avformat.lib}. With these libraries you can link your Visual C++
923
code directly with the FFmpeg DLLs (see below).
924

    
925
@end itemize
926

    
927
@subsection Visual C++ compatibility
928

    
929
FFmpeg will not compile under Visual C++ -- and it has too many
930
dependencies on the GCC compiler to make a port viable. However,
931
if you want to use the FFmpeg libraries in your own applications,
932
you can still compile those applications using Visual C++. An
933
important restriction to this is that you have to use the
934
dynamically linked versions of the FFmpeg libraries (i.e. the
935
DLLs), and you have to make sure that Visual-C++-compatible
936
import libraries are created during the FFmpeg build process.
937

    
938
This description of how to use the FFmpeg libraries with Visual C++ is
939
based on Visual C++ 2005 Express Edition Beta 2. If you have a different
940
version, you might have to modify the procedures slightly.
941

    
942
Here are the step-by-step instructions for building the FFmpeg libraries
943
so they can be used with Visual C++:
944

    
945
@enumerate
946

    
947
@item Install Visual C++ (if you haven't done so already).
948

    
949
@item Install MinGW and MSYS as described above.
950

    
951
@item Add a call to @file{vcvars32.bat} (which sets up the environment
952
variables for the Visual C++ tools) as the first line of
953
@file{msys.bat}. The standard location for @file{vcvars32.bat} is
954
@file{C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat},
955
and the standard location for @file{msys.bat} is
956
@file{C:\msys\1.0\msys.bat}. If this corresponds to your setup, add the
957
following line as the first line of @file{msys.bat}:
958

    
959
@code{call "C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat"}
960

    
961
@item Start the MSYS shell (file @file{msys.bat}) and type @code{link.exe}.
962
If you get a help message with the command line options of @code{link.exe},
963
this means your environment variables are set up correctly, the
964
Microsoft linker is on the path and will be used by FFmpeg to
965
create Visual-C++-compatible import libraries.
966

    
967
@item Extract the current version of FFmpeg and change to the FFmpeg directory.
968

    
969
@item Type the command
970
@code{./configure --enable-shared --enable-memalign-hack} to configure and,
971
if that didn't produce any errors, type @code{make} to build FFmpeg.
972

    
973
@item The subdirectories @file{libavformat}, @file{libavcodec}, and
974
@file{libavutil} should now contain the files @file{avformat.dll},
975
@file{avformat.lib}, @file{avcodec.dll}, @file{avcodec.lib},
976
@file{avutil.dll}, and @file{avutil.lib}, respectively. Copy the three
977
DLLs to your System32 directory (typically @file{C:\Windows\System32}).
978

    
979
@end enumerate
980

    
981
And here is how to use these libraries with Visual C++:
982

    
983
@enumerate
984

    
985
@item Create a new console application ("File / New / Project") and then
986
select "Win32 Console Application". On the appropriate page of the
987
Application Wizard, uncheck the "Precompiled headers" option.
988

    
989
@item Write the source code for your application, or, for testing, just
990
copy the code from an existing sample application into the source file
991
that Visual C++ has already created for you. (Note that your source
992
filehas to have a @code{.cpp} extension; otherwise, Visual C++ won't
993
compile the FFmpeg headers correctly because in C mode, it doesn't
994
recognize the @code{inline} keyword.)  For example, you can copy
995
@file{output_example.c} from the FFmpeg distribution (but you will
996
have to make minor modifications so the code will compile under
997
C++, see below).
998

    
999
@item Open the "Project / Properties" dialog box. In the "Configuration"
1000
combo box, select "All Configurations" so that the changes you make will
1001
affect both debug and release builds. In the tree view on the left hand
1002
side, select "C/C++ / General", then edit the "Additional Include
1003
Directories" setting to contain the complete paths to the
1004
@file{libavformat}, @file{libavcodec}, and @file{libavutil}
1005
subdirectories of your FFmpeg directory. Note that the directories have
1006
to be separated using semicolons. Now select "Linker / General" from the
1007
tree view and edit the "Additional Library Directories" setting to
1008
contain the same three directories.
1009

    
1010
@item Still in the "Project / Properties" dialog box, select "Linker / Input"
1011
from the tree view, then add the files @file{avformat.lib},
1012
@file{avcodec.lib}, and @file{avutil.lib} to the end of the "Additional
1013
Dependencies". Note that the names of the libraries have to be separated
1014
using spaces.
1015

    
1016
@item Now, select "C/C++ / Preprocessor" from the tree view. Select "Debug"
1017
in the "Configuration" combo box. Add @code{EMULATE_INTTYPES} to the
1018
"Preprocessor Definitions". (Note that the various preprocessor
1019
definitions have to be separated using semicolons.) Select "Release" in
1020
the "Configuration" combo box and, again, add @code{EMULATE_INTTYPES} to
1021
the "Preprocessor Definitions". (This has to be done separately because
1022
debug and release builds have different preprocessor definitions.)
1023
Finally, select "C/C++ / Code Generation" from the tree view. Select
1024
"Debug" in the "Configuration" combo box. Make sure that "Runtime
1025
Library" is set to "Multi-threaded Debug DLL". Then, select "Release" in
1026
the "Configuration" combo box and make sure that "Runtime Library" is
1027
set to "Multi-threaded DLL".
1028

    
1029
@item Click "OK" to close the "Project / Properties" dialog box and build
1030
the application. Hopefully, it should compile and run cleanly. If you
1031
used @file{output_example.c} as your sample application, you will get a
1032
few compiler errors, but they are easy to fix. The first type of error
1033
occurs because Visual C++ doesn't allow an @code{int} to be converted to
1034
an @code{enum} without a cast. To solve the problem, insert the required
1035
casts (this error occurs once for a @code{CodecID} and once for a
1036
@code{CodecType}).  The second type of error occurs because C++ requires
1037
the return value of @code{malloc} to be cast to the exact type of the
1038
pointer it is being assigned to. Visual C++ will complain that, for
1039
example, @code{(void *)} is being assigned to @code{(uint8_t *)} without
1040
an explicit cast. So insert an explicit cast in these places to silence
1041
the compiler. The third type of error occurs because the @code{snprintf}
1042
library function is called @code{_snprintf} under Visual C++.  So just
1043
add an underscore to fix the problem. With these changes,
1044
@file{output_example.c} should compile under Visual C++, and the
1045
resulting executable should produce valid video files.
1046

    
1047
@end enumerate
1048

    
1049
@subsection Cross compilation for Windows with Linux
1050

    
1051
You must use the MinGW cross compilation tools available at
1052
@url{http://www.mingw.org/}.
1053

    
1054
Then configure FFmpeg with the following options:
1055
@example
1056
./configure --enable-mingw32 --cross-prefix=i386-mingw32msvc-
1057
@end example
1058
(you can change the cross-prefix according to the prefix chosen for the
1059
MinGW tools).
1060

    
1061
Then you can easily test FFmpeg with Wine
1062
(@url{http://www.winehq.com/}).
1063

    
1064
@section Mac OS X
1065

    
1066
@section BeOS
1067

    
1068
The configure script should guess the configuration itself.
1069
Networking support is currently not finished.
1070
errno issues fixed by Andrew Bachmann.
1071

    
1072
Old stuff:
1073

    
1074
Fran├žois Revol - revol at free dot fr - April 2002
1075

    
1076
The configure script should guess the configuration itself, 
1077
however I still didn't test building on the net_server version of BeOS.
1078

    
1079
FFserver is broken (needs poll() implementation).
1080

    
1081
There are still issues with errno codes, which are negative in BeOS, and
1082
that FFmpeg negates when returning. This ends up turning errors into 
1083
valid results, then crashes.
1084
(To be fixed)
1085

    
1086
@chapter Developers Guide
1087

    
1088
@section API
1089
@itemize
1090
@item libavcodec is the library containing the codecs (both encoding and
1091
decoding). Look at @file{libavcodec/apiexample.c} to see how to use it.
1092

    
1093
@item libavformat is the library containing the file format handling (mux and
1094
demux code for several formats). Look at @file{ffplay.c} to use it in a
1095
player. See @file{output_example.c} to use it to generate audio or video
1096
streams.
1097

    
1098
@end itemize
1099

    
1100
@section Integrating libavcodec or libavformat in your program
1101

    
1102
You can integrate all the source code of the libraries to link them
1103
statically to avoid any version problem. All you need is to provide a
1104
'config.mak' and a 'config.h' in the parent directory. See the defines
1105
generated by ./configure to understand what is needed.
1106

    
1107
You can use libavcodec or libavformat in your commercial program, but
1108
@emph{any patch you make must be published}. The best way to proceed is
1109
to send your patches to the FFmpeg mailing list.
1110

    
1111
@node Coding Rules
1112
@section Coding Rules
1113

    
1114
FFmpeg is programmed in the ISO C90 language with a few additional
1115
features from ISO C99, namely:
1116
@itemize @bullet
1117
@item
1118
the @samp{inline} keyword;
1119
@item
1120
@samp{//} comments;
1121
@item
1122
designated struct initializers (@samp{struct s x = @{ .i = 17 @};})
1123
@item
1124
compound literals (@samp{x = (struct s) @{ 17, 23 @};})
1125
@end itemize
1126

    
1127
These features are supported by all compilers we care about, so we won't
1128
accept patches to remove their use unless they absolutely don't impair
1129
clarity and performance.
1130

    
1131
All code must compile with GCC 2.95 and GCC 3.3. Currently, FFmpeg also
1132
compiles with several other compilers, such as the Compaq ccc compiler
1133
or Sun Studio 9, and we would like to keep it that way unless it would
1134
be exceedingly involved. To ensure compatibility, please don't use any
1135
additional C99 features or GCC extensions. Especially watch out for:
1136
@itemize @bullet
1137
@item
1138
mixing statements and declarations;
1139
@item
1140
@samp{long long} (use @samp{int64_t} instead);
1141
@item
1142
@samp{__attribute__} not protected by @samp{#ifdef __GNUC__} or similar;
1143
@item
1144
GCC statement expressions (@samp{(x = (@{ int y = 4; y; @})}).
1145
@end itemize
1146

    
1147
Indent size is 4. The TAB character should not be used.
1148
The presentation is the one specified by 'indent -i4 -kr'.
1149

    
1150
Main priority in FFmpeg is simplicity and small code size (=less
1151
bugs).
1152

    
1153
Comments: Use the JavaDoc/Doxygen
1154
format (see examples below) so that code documentation
1155
can be generated automatically. All nontrivial functions should have a comment
1156
above them explaining what the function does, even if it's just one sentence.
1157
All structures and their member variables should be documented, too.
1158
@example
1159
/**
1160
 * @@file mpeg.c
1161
 * MPEG codec.
1162
 * @@author ...
1163
 */
1164

    
1165
/**
1166
 * Summary sentence.
1167
 * more text ...
1168
 * ...
1169
 */
1170
typedef struct Foobar@{
1171
    int var1; /**< var1 description */
1172
    int var2; ///< var2 description
1173
    /** var3 description */
1174
    int var3;
1175
@} Foobar;
1176

    
1177
/**
1178
 * Summary sentence.
1179
 * more text ...
1180
 * ...
1181
 * @@param my_parameter description of my_parameter
1182
 * @@return return value description
1183
 */
1184
int myfunc(int my_parameter)
1185
...
1186
@end example
1187

    
1188
fprintf and printf are forbidden in libavformat and libavcodec, 
1189
please use av_log() instead.
1190

    
1191
@node CVS Policy
1192
@section CVS Policy
1193

    
1194
@enumerate
1195
@item 
1196
   You must not commit code which breaks FFmpeg! (Meaning unfinished but
1197
   enabled code which breaks compilation or compiles but does not work or
1198
   breaks the regression tests)
1199
   You can commit unfinished stuff (for testing etc), but it must be disabled
1200
   (#ifdef etc) by default so it does not interfere with other developers'
1201
   work.
1202
@item 
1203
   You don't have to over-test things. If it works for you, and you think it
1204
   should work for others, then commit. If your code has problems
1205
   (portability, triggers compiler bugs, unusual environment etc) they will be
1206
   reported and eventually fixed.
1207
@item 
1208
   Do not commit unrelated changes together, split them into self-contained
1209
   pieces.
1210
@item
1211
   Do not change behavior of the program (renaming options etc) without
1212
   first discussing it on the ffmpeg-devel mailing list. Do not remove
1213
   functionality from the code. Just improve!
1214
   
1215
   Note: Redundant code can be removed.
1216
@item
1217
   Do not commit changes to the build system (Makefiles, configure script)
1218
   which change behavior, defaults etc, without asking first. The same
1219
   applies to compiler warning fixes, trivial looking fixes and to code
1220
   maintained by other developers. We usually have a reason for doing things
1221
   the way we do. Send your changes as patches to the ffmpeg-devel mailing
1222
   list, and if the code maintainers say OK, you may commit. This does not
1223
   apply to files you wrote and/or maintain.
1224
@item
1225
   We refuse source indentation and other cosmetic changes if they are mixed
1226
   with functional changes, such commits will be rejected and removed. Every
1227
   developer has his own indentation style, you should not change it. Of course
1228
   if you (re)write something, you can use your own style, even though we would
1229
   prefer if the indentation throughout FFmpeg was consistent (Many projects
1230
   force a given indentation style - we don't.). If you really need to make
1231
   indentation changes (try to avoid this), separate them strictly from real
1232
   changes.
1233

    
1234
   NOTE: If you had to put if()@{ .. @} over a large (> 5 lines) chunk of code,
1235
   then either do NOT change the indentation of the inner part within (don't 
1236
   move it to the right)! or do so in a separate commit
1237
@item
1238
   Always fill out the commit log message. Describe in a few lines what you
1239
   changed and why. You can refer to mailing list postings if you fix a
1240
   particular bug. Comments such as "fixed!" or "Changed it." are unacceptable.
1241
@item
1242
   If you apply a patch by someone else, include the name and email address in
1243
   the CVS log message. Since the ffmpeg-cvslog mailing list is publicly
1244
   archived you should add some SPAM protection to the email address. Send an
1245
   answer to ffmpeg-devel (or wherever you got the patch from) saying that
1246
   you applied the patch.
1247
@item
1248
   Do NOT commit to code actively maintained by others without permission. Send
1249
   a patch to ffmpeg-devel instead.
1250
@item
1251
    Subscribe to the ffmpeg-cvslog mailing list. The diffs of all CVS commits
1252
    are sent there and reviewed by all the other developers. Bugs and possible
1253
    improvements or general questions regarding commits are discussed there. We
1254
    expect you to react if problems with your code are uncovered.
1255
@item
1256
    Update the documentation if you change behavior or add features. If you are
1257
    unsure how best to do this, send a patch to ffmpeg-devel, the documentation
1258
    maintainer(s) will review and commit your stuff.
1259
@item
1260
    Revert a commit ONLY in case of a big blunder like committing something not
1261
    intended to be committed or committing a wrong file, the wrong version of a
1262
    patch, CVS policy violation or broken code and you are going to recommit the
1263
    right thing immediately.
1264

    
1265
    Never revert changes made a long time ago or buggy code. Fix it in the
1266
    normal way instead.
1267
@item
1268
    Never write to unallocated memory, never write over the end of arrays,
1269
    always check values read from some untrusted source before using them
1270
    as array index or other risky things.
1271
@end enumerate
1272

    
1273
We think our rules are not too hard. If you have comments, contact us.
1274

    
1275
Note, these rules are mostly borrowed from the MPlayer project.
1276

    
1277
@subsection Renaming/moving files or content of files
1278
  You CANNOT do that. Post a request for such a change to the mailing list
1279
  Do NOT remove & readd a file - it will kill the changelog!!!!
1280

    
1281
@section Submitting patches
1282

    
1283
First, (@pxref{Coding Rules}) above if you didn't yet.
1284

    
1285
When you submit your patch, try to send a unified diff (diff '-up'
1286
option). I cannot read other diffs :-)
1287

    
1288
Also please do not submit patches which contain several unrelated changes.
1289
Split them into individual self-contained patches; this makes reviewing 
1290
them much easier.
1291

    
1292
Run the regression tests before submitting a patch so that you can
1293
verify that there are no big problems.
1294

    
1295
Patches should be posted as base64 encoded attachments (or any other
1296
encoding which ensures that the patch won't be trashed during
1297
transmission) to the ffmpeg-devel mailing list, see 
1298
@url{http://www1.mplayerhq.hu/mailman/listinfo/ffmpeg-devel}
1299

    
1300
It also helps quite a bit if you tell us what the patch does (for example
1301
'replaces lrint by lrintf'), and why (for example '*BSD isn't C99 compliant
1302
and has no lrint()')
1303

    
1304
We reply to all submitted patches and either apply or reject with some
1305
explanation why, but sometimes we are quite busy so it can take a week or two.
1306

    
1307
@section Regression tests
1308

    
1309
Before submitting a patch (or committing to CVS), you should at least
1310
test that you did not break anything.
1311

    
1312
The regression tests build a synthetic video stream and a synthetic
1313
audio stream. These are then encoded and decoded with all codecs or
1314
formats. The CRC (or MD5) of each generated file is recorded in a
1315
result file. A 'diff' is launched to compare the reference results and
1316
the result file.
1317

    
1318
The regression tests then go on to test the FFserver code with a
1319
limited set of streams. It is important that this step runs correctly
1320
as well.
1321

    
1322
Run 'make test' to test all the codecs and formats.
1323

    
1324
Run 'make fulltest' to test all the codecs, formats and FFserver.
1325

    
1326
[Of course, some patches may change the results of the regression tests. In
1327
this case, the reference results of the regression tests shall be modified
1328
accordingly].
1329

    
1330
@bye