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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 the parameters, when
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possible. You have usually to give only the target 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. You can use any TV viewer such as xawtv
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(@url{http://bytesex.org/xawtv/}) by Gerd Knorr which I find very
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good. You must also set correctly the audio recording levels 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 input from YUV files:
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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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The RAW YUV420P is a file containing RAW YUV planar, for each frame first
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come the Y plane followed by U and V planes, which are 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 -o 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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Convert 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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Convert the sample rate of a.wav to 22050 Hz and encode it to MPEG audio.
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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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Convert a.wav to a.mp2 at 64 kbits and b.mp2 at 128 kbits. '-map
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file:index' specify 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 ripper example, input from a VOB file, output
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to 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, GOP
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size is 300 that means an INTRA frame every 10 seconds for 29.97 fps
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input video.  Also the audio stream is MP3 encoded so you need LAME
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support which is enabled using @code{--enable-mp3lame} when
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configuring.  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. 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 parameter 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 file name
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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. @code{hh:mm:ss[.xxx]} syntax is also
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supported.
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@item -ss position
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seek to given time position. @code{hh:mm:ss[.xxx]} syntax is also
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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", "ntsc-svcd", ... ). All the format
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options (bitrate, codecs, buffer sizes) are automatically set by this
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option. 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 they do not compromise the
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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. @code{[-]hh:mm:ss[.xxx]} syntax
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is also supported.  This option affects all the input files that
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follow it.  The offset is added to the input files' timestamps;
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specifying a positive offset means that the corresponding streams are
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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).  The
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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 pad color is expressed 
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as a six digit hexadecimal number where the first two digits represent red, 
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middle two digits green and last two digits blue. Defaults to 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 ratecontrol 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 pass and
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the video at the exact requested bit rate is generated in the second
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pass.
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@item -passlogfile file   
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select two pass log file 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 picture 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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min video quantiser scale (VBR)
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@item -qmax q             
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max video quantiser scale (VBR)
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@item -qdiff q            
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max difference between the quantiser scale (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 1-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 is @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}. Available methods are
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(from lower 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_CAREFULL (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: chooses 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 (only MPEG-4)
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@item -part
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use data partitioning (only MPEG-4)
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@item -bug param
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workaround not auto detected encoder bugs
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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 (only MPEG-2 and MPEG-4). Use this option
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if your input file is interlaced and if you want to keep the interlaced
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format for minimum losses. The alternative is to deinterlace the input
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stream with @option{-deinterlace}, but deinterlacing introduces more
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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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tell 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 ffserver automatic 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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(Zero 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 the standard input or to write
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to the standard output.
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ffmpeg handles also many protocols specified with the URL syntax.
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Use 'ffmpeg -formats' to have 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 bit rate application, use a low frame rate
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and a small GOP size. This is especially true for real video 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 of 1 indicates that a very good quality could
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be achieved. The value of 31 indicates the worst quality. If q=31
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too often, it means that the encoder cannot compress enough to meet
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your bit rate. You must either increase the bit rate, 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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completely motion estimation (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 bitrates in audio, 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 in the encoder the same quality factor than in the decoder. It
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allows to be almost lossless in 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
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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 MPEG1 systems @tab X  @tab  X 
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@tab muxed audio and video
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@item MPEG2 PS @tab X  @tab  X 
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@tab also known as @code{VOB} file
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@item MPEG2 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 
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@item SUN AU format @tab X  @tab  X 
665
@item NUT @tab X @tab X @tab NUT Open Container Format
666
@item QuickTime        @tab X @tab  X 
667
@item MPEG4            @tab X @tab  X 
668
@tab MPEG4 is a variant of QuickTime
669
@item Raw MPEG4 video  @tab  X @tab  X 
670
@item DV               @tab  X @tab  X
671
@item 4xm              @tab    @tab X
672
@tab 4X Technologies format, used in some games
673
@item Playstation STR  @tab    @tab X
674
@item Id RoQ           @tab    @tab X
675
@tab used in Quake III, Jedi Knight 2, other computer games
676
@item Interplay MVE    @tab    @tab X
677
@tab format used in various Interplay computer games
678
@item WC3 Movie        @tab    @tab X
679
@tab multimedia format used in Origin's Wing Commander III computer game
680
@item Sega FILM/CPK    @tab    @tab X
681
@tab used in many Sega Saturn console games
682
@item Westwood Studios VQA/AUD  @tab    @tab X
683
@tab Multimedia formats used in Westwood Studios games
684
@item Id Cinematic (.cin) @tab    @tab X
685
@tab Used in Quake II
686
@item FLIC format      @tab    @tab X
687
@tab .fli/.flc files
688
@item Sierra VMD       @tab    @tab X
689
@tab used in Sierra CD-ROM games
690
@item Sierra Online    @tab    @tab X
691
@tab .sol files used in Sierra Online games
692
@item Matroska         @tab    @tab X
693
@item Electronic Arts Multimedia    @tab    @tab X
694
@tab used in various EA games; files have extensions like WVE and UV2
695
@item Nullsoft Video (NSV) format @tab    @tab X
696
@end multitable
697

    
698
@code{X} means that the encoding (resp. decoding) is supported.
699

    
700
@section Image Formats
701

    
702
FFmpeg can read and write images for each frame of a video sequence. The
703
following image formats are supported:
704

    
705
@multitable @columnfractions .4 .1 .1
706
@item Supported Image Format @tab Encoding @tab Decoding @tab Comments
707
@item PGM, PPM     @tab X @tab X 
708
@item PAM          @tab X @tab X @tab PAM is a PNM extension with alpha support
709
@item PGMYUV       @tab X @tab X @tab PGM with U and V components in YUV 4:2:0
710
@item JPEG         @tab X @tab X @tab Progressive JPEG is not supported
711
@item .Y.U.V       @tab X @tab X @tab One raw file per component
712
@item Animated GIF @tab X @tab X @tab Only uncompressed GIFs are generated
713
@item PNG          @tab X @tab X @tab 2 bit and 4 bit/pixel not supported yet
714
@item SGI          @tab X @tab X @tab SGI RGB image format
715
@end multitable
716

    
717
@code{X} means that the encoding (resp. decoding) is supported.
718

    
719
@section Video Codecs
720

    
721
@multitable @columnfractions .4 .1 .1 .7
722
@item Supported Codec @tab Encoding @tab Decoding @tab Comments
723
@item MPEG1 video            @tab  X  @tab  X
724
@item MPEG2 video            @tab  X  @tab  X 
725
@item MPEG4                  @tab  X  @tab  X @tab Also known as DivX4/5
726
@item MSMPEG4 V1             @tab  X  @tab  X
727
@item MSMPEG4 V2             @tab  X  @tab  X
728
@item MSMPEG4 V3             @tab  X  @tab  X @tab Also known as DivX3
729
@item WMV7                   @tab  X  @tab  X
730
@item WMV8                   @tab  X  @tab  X @tab Not completely working
731
@item H.261                  @tab  X  @tab  X
732
@item H.263(+)               @tab  X  @tab  X @tab Also known as Real Video 1.0
733
@item H.264                  @tab     @tab  X
734
@item MJPEG                  @tab  X  @tab  X 
735
@item Lossless MJPEG         @tab  X  @tab  X
736
@item Apple MJPEG-B          @tab     @tab  X
737
@item Sunplus MJPEG          @tab     @tab  X @tab fourcc: SP5X
738
@item DV                     @tab  X  @tab  X 
739
@item Huff YUV               @tab  X  @tab  X
740
@item FFmpeg Video 1         @tab  X  @tab  X @tab Experimental lossless codec (fourcc: FFV1)
741
@item FFmpeg Snow            @tab  X  @tab  X @tab Experimental wavelet codec (fourcc: SNOW)
742
@item Asus v1                @tab  X  @tab  X @tab fourcc: ASV1
743
@item Asus v2                @tab  X  @tab  X @tab fourcc: ASV2
744
@item Creative YUV           @tab     @tab  X @tab fourcc: CYUV
745
@item Sorenson Video 1       @tab  X  @tab  X @tab fourcc: SVQ1
746
@item Sorenson Video 3       @tab     @tab  X @tab fourcc: SVQ3
747
@item On2 VP3                @tab     @tab  X @tab still experimental
748
@item Theora                 @tab     @tab  X @tab still experimental
749
@item Intel Indeo 3          @tab     @tab  X
750
@item FLV                    @tab  X  @tab  X @tab Sorenson H.263 used in Flash
751
@item ATI VCR1               @tab     @tab  X @tab fourcc: VCR1
752
@item ATI VCR2               @tab     @tab  X @tab fourcc: VCR2
753
@item Cirrus Logic AccuPak   @tab     @tab  X @tab fourcc: CLJR
754
@item 4X Video               @tab     @tab  X @tab used in certain computer games
755
@item Sony Playstation MDEC  @tab     @tab  X 
756
@item Id RoQ                 @tab     @tab  X @tab used in Quake III, Jedi Knight 2, other computer games
757
@item Xan/WC3                @tab     @tab  X @tab used in Wing Commander III .MVE files
758
@item Interplay Video        @tab     @tab  X @tab used in Interplay .MVE files
759
@item Apple Animation        @tab     @tab  X @tab fourcc: 'rle '
760
@item Apple Graphics         @tab     @tab  X @tab fourcc: 'smc '
761
@item Apple Video            @tab     @tab  X @tab fourcc: rpza
762
@item Apple QuickDraw        @tab     @tab  X @tab fourcc: qdrw
763
@item Cinepak                @tab     @tab  X
764
@item Microsoft RLE          @tab     @tab  X
765
@item Microsoft Video-1      @tab     @tab  X
766
@item Westwood VQA           @tab     @tab  X
767
@item Id Cinematic Video     @tab     @tab  X @tab used in Quake II
768
@item Planar RGB             @tab     @tab  X @tab fourcc: 8BPS
769
@item FLIC video             @tab     @tab  X
770
@item Duck TrueMotion v1     @tab     @tab  X @tab fourcc: DUCK
771
@item VMD Video              @tab     @tab  X @tab used in Sierra VMD files
772
@item MSZH                   @tab     @tab  X @tab Part of LCL
773
@item ZLIB                   @tab  X  @tab  X @tab Part of LCL, encoder experimental
774
@item TechSmith Camtasia     @tab     @tab  X @tab fourcc: TSCC
775
@item IBM Ultimotion         @tab     @tab  X @tab fourcc: ULTI
776
@item Miro VideoXL           @tab     @tab  X @tab fourcc: VIXL
777
@item QPEG                   @tab     @tab  X @tab fourccs: QPEG, Q1.0, Q1.1
778
@item LOCO                   @tab     @tab  X @tab 
779
@item Winnov WNV1            @tab     @tab  X @tab 
780
@item Autodesk Animator Studio Codec  @tab     @tab  X @tab fourcc: AASC
781
@item Fraps FPS1             @tab     @tab  X @tab 
782
@end multitable
783

    
784
@code{X} means that the encoding (resp. decoding) is supported.
785

    
786
Check at @url{http://www.mplayerhq.hu/~michael/codec-features.html} to
787
get a precise comparison of FFmpeg MPEG4 codec compared to the other
788
solutions.
789

    
790
@section Audio Codecs
791

    
792
@multitable @columnfractions .4 .1 .1 .1 .7
793
@item Supported Codec @tab Encoding @tab Decoding @tab Comments
794
@item MPEG audio layer 2     @tab  IX  @tab  IX 
795
@item MPEG audio layer 1/3   @tab IX   @tab  IX
796
@tab MP3 encoding is supported through the external library LAME
797
@item AC3                    @tab  IX  @tab  IX
798
@tab liba52 is used internally for decoding
799
@item Vorbis                 @tab  X   @tab  X
800
@tab supported through the external library libvorbis
801
@item WMA V1/V2              @tab      @tab X
802
@item AAC                    @tab X    @tab X
803
@tab supported through the external library libfaac/libfaad
804
@item Microsoft ADPCM        @tab X    @tab X
805
@item MS IMA ADPCM           @tab X    @tab X
806
@item QT IMA ADPCM           @tab      @tab X
807
@item 4X IMA ADPCM           @tab      @tab X
808
@item G.726  ADPCM           @tab X    @tab X
809
@item Duck DK3 IMA ADPCM     @tab      @tab X
810
@tab used in some Sega Saturn console games
811
@item Duck DK4 IMA ADPCM     @tab      @tab X
812
@tab used in some Sega Saturn console games
813
@item Westwood Studios IMA ADPCM @tab      @tab X
814
@tab used in Westwood Studios games like Command and Conquer
815
@item SMJPEG IMA ADPCM       @tab      @tab X
816
@tab used in certain Loki game ports
817
@item CD-ROM XA ADPCM        @tab      @tab X
818
@item CRI ADX ADPCM          @tab X    @tab X
819
@tab used in Sega Dreamcast games
820
@item Electronic Arts ADPCM  @tab      @tab X
821
@tab used in various EA titles
822
@item Creative ADPCM         @tab      @tab X
823
@item RA144                  @tab      @tab X
824
@tab Real 14400 bit/s codec
825
@item RA288                  @tab      @tab X
826
@tab Real 28800 bit/s codec
827
@item RADnet                 @tab X    @tab IX
828
@tab Real low bitrate AC3 codec, liba52 is used for decoding
829
@item AMR-NB                 @tab X    @tab X
830
@tab supported through an external library
831
@item AMR-WB                 @tab X    @tab X
832
@tab supported through an external library
833
@item DV audio               @tab      @tab X
834
@item Id RoQ DPCM            @tab      @tab X
835
@tab used in Quake III, Jedi Knight 2, other computer games
836
@item Interplay MVE DPCM     @tab      @tab X
837
@tab used in various Interplay computer games
838
@item Xan DPCM               @tab      @tab X
839
@tab used in Origin's Wing Commander IV AVI files
840
@item Sierra Online DPCM     @tab      @tab X
841
@tab used in Sierra Online game audio files
842
@item Apple MACE 3           @tab      @tab X
843
@item Apple MACE 6           @tab      @tab X
844
@item FLAC lossless audio    @tab      @tab X
845
@item Shorten lossless audio @tab      @tab X
846
@item Apple lossless audio   @tab      @tab X
847
@tab QuickTime fourcc 'alac'
848
@item FFmpeg Sonic           @tab X    @tab X
849
@tab Experimental lossy/lossless codec
850
@end multitable
851

    
852
@code{X} means that the encoding (resp. decoding) is supported.
853

    
854
@code{I} means that an integer only version is available too (ensures highest
855
performances on systems without hardware floating point support).
856

    
857
@chapter Platform Specific information
858

    
859
@section Linux
860

    
861
ffmpeg should be compiled with at least GCC 2.95.3. GCC 3.2 is the
862
preferred compiler now for ffmpeg. All future optimizations will depend on
863
features only found in GCC 3.2.
864

    
865
@section BSD
866

    
867
@section Windows
868

    
869
@subsection Native Windows compilation
870

    
871
@itemize
872
@item Install the current versions of MSYS and MinGW from
873
@url{http://www.mingw.org/}. You can find detailed installation
874
instructions in the download section and the FAQ.
875

    
876
@item If you want to test the FFmpeg Simple Media Player, also download 
877
the MinGW development library of SDL 1.2.x
878
(@file{SDL-devel-1.2.x-mingw32.tar.gz}) from
879
@url{http://www.libsdl.org}. Unpack it in a temporary place, and
880
unpack the archive @file{i386-mingw32msvc.tar.gz} in the MinGW tool
881
directory. Edit the @file{sdl-config} script so that it gives the
882
correct SDL directory when invoked.
883

    
884
@item Extract the current version of FFmpeg (the latest release version or the current CVS snapshot whichever is recommended).
885
 
886
@item Start the MSYS shell (file @file{msys.bat}).
887

    
888
@item Change to the FFMPEG directory and follow
889
 the instructions of how to compile ffmpeg (file
890
@file{INSTALL}). Usually, launching @file{./configure} and @file{make}
891
suffices. If you have problems using SDL, verify that
892
@file{sdl-config} can be launched from the MSYS command line.
893

    
894
@item You can install FFmpeg in @file{Program Files/FFmpeg} by typing @file{make install}. Don't forget to copy @file{SDL.dll} at the place you launch 
895
@file{ffplay}.
896

    
897
@end itemize
898

    
899
Notes: 
900
@itemize
901

    
902
@item The target @file{make wininstaller} can be used to create a
903
Nullsoft based Windows installer for FFmpeg and FFplay. @file{SDL.dll}
904
must be copied in the ffmpeg directory in order to build the
905
installer.
906

    
907
@item By using @code{./configure --enable-shared} when configuring ffmpeg, 
908
you can build @file{avcodec.dll} and @file{avformat.dll}. With
909
@code{make install} you install the FFmpeg DLLs and the associated
910
headers in @file{Program Files/FFmpeg}. 
911

    
912
@item Visual C++ compatibility: if you used @code{./configure --enable-shared} 
913
when configuring FFmpeg, then FFmpeg tries to use the Microsoft Visual
914
C++ @code{lib} tool to build @code{avcodec.lib} and
915
@code{avformat.lib}. With these libraries, you can link your Visual C++
916
code directly with the FFmpeg DLLs.
917

    
918
@end itemize
919

    
920
@subsection Cross compilation for Windows with Linux
921

    
922
You must use the MinGW cross compilation tools available at
923
@url{http://www.mingw.org/}.
924

    
925
Then configure ffmpeg with the following options:
926
@example
927
./configure --enable-mingw32 --cross-prefix=i386-mingw32msvc-
928
@end example
929
(you can change the cross-prefix according to the prefix chosen for the
930
MinGW tools).
931

    
932
Then you can easily test ffmpeg with wine
933
(@url{http://www.winehq.com/}).
934

    
935
@section Mac OS X
936

    
937
@section BeOS
938

    
939
The configure script should guess the configuration itself.
940
Networking support is currently not finished.
941
errno issues fixed by Andrew Bachmann.
942

    
943
Old stuff:
944

    
945
Fran?ois Revol - revol at free dot fr - April 2002
946

    
947
The configure script should guess the configuration itself, 
948
however I still didn't tested building on net_server version of BeOS.
949

    
950
ffserver is broken (needs poll() implementation).
951

    
952
There is still issues with errno codes, which are negative in BeOS, and
953
that ffmpeg negates when returning. This ends up turning errors into 
954
valid results, then crashes.
955
(To be fixed)
956

    
957
@chapter Developers Guide
958

    
959
@section API
960
@itemize
961
@item libavcodec is the library containing the codecs (both encoding and
962
  decoding). See @file{libavcodec/apiexample.c} to see how to use it.
963

    
964
@item libavformat is the library containing the file formats handling (mux and
965
  demux code for several formats). See @file{ffplay.c} to use it in a
966
player. See @file{output_example.c} to use it to generate audio or video
967
streams.
968

    
969
@end itemize
970

    
971
@section Integrating libavcodec or libavformat in your program
972

    
973
You can integrate all the source code of the libraries to link them
974
statically to avoid any version problem. All you need is to provide a
975
'config.mak' and a 'config.h' in the parent directory. See the defines
976
generated by ./configure to understand what is needed.
977

    
978
You can use libavcodec or libavformat in your commercial program, but
979
@emph{any patch you make must be published}. The best way to proceed is
980
to send your patches to the ffmpeg mailing list.
981

    
982
@node Coding Rules
983
@section Coding Rules
984

    
985
ffmpeg is programmed in the ISO C90 language with a few additional
986
features from ISO C99, namely:
987
@itemize @bullet
988
@item
989
the @samp{inline} keyword;
990
@item
991
@samp{//} comments;
992
@item
993
designated struct initializers (@samp{struct s x = @{ .i = 17 @};})
994
@item
995
compound literals (@samp{x = (struct s) @{ 17, 23 @};})
996
@end itemize
997

    
998
These features are supported by all compilers we care about, so we won't
999
accept patches to remove their use unless they absolutely don't impair
1000
clarity and performance.
1001

    
1002
All code must compile with GCC 2.95 and GCC 3.3. Currently, ffmpeg also
1003
compiles with several other compilers, such as the Compaq ccc compiler
1004
or Sun Studio 9, and we would like to keep it that way unless it would
1005
be exceedingly involved. To ensure compatibility, please don't use any
1006
additional C99 features or GCC extensions. Watch out especially for:
1007
@itemize @bullet
1008
@item
1009
mixing statements and declarations;
1010
@item
1011
@samp{long long} (use @samp{int64_t} instead);
1012
@item
1013
@samp{__attribute__} not protected by @samp{#ifdef __GNUC__} or similar;
1014
@item
1015
GCC statement expressions (@samp{(x = (@{ int y = 4; y; @})}).
1016
@end itemize
1017

    
1018
Indent size is 4. The TAB character should not be used.
1019
The presentation is the one specified by 'indent -i4 -kr'.
1020

    
1021
Main priority in ffmpeg is simplicity and small code size (=less
1022
bugs).
1023

    
1024
Comments: use the JavaDoc/Doxygen 
1025
format (see examples below) so that a documentation
1026
can be generated automatically. All non trivial functions should have a comment
1027
above it explaining what the function does, even if its just one sentence.
1028
All Structures and their member variables should be documented too.
1029
@example
1030
/**
1031
?* @@file mpeg.c
1032
?* mpeg codec.
1033
?* @@author ...
1034
?*/
1035

    
1036
/**
1037
?* Summary sentence.
1038
?* more text ...
1039
?* ...
1040
?*/
1041
typedef struct Foobar@{
1042
? ? int var1; /**< var1 description */
1043
? ? int var2; ///< var2 description
1044
? ? /** var3 description */
1045
? ? int var3;
1046
@} Foobar;
1047

    
1048
/**
1049
?* Summary sentence.
1050
?* more text ...
1051
?* ...
1052
?* @@param my_parameter description of my_parameter
1053
?* @@return return value description
1054
?*/
1055
int myfunc(int my_parameter)
1056
...
1057
@end example
1058

    
1059
fprintf and printf are forbidden in libavformat and libavcodec, 
1060
please use av_log() instead.
1061

    
1062
@node CVS Policy
1063
@section CVS Policy
1064

    
1065
@enumerate
1066
@item 
1067
   You must not commit code which breaks FFmpeg! (Meaning unfinished but
1068
   enabled code which breaks compilation or compiles but does not work. Or 
1069
   breaks the regression tests)
1070
   You can commit unfinished stuff (for testing etc), but it must be disabled
1071
   (#ifdef etc) by default so it does not interfere with other developers'
1072
   work.
1073
@item 
1074
   You don't have to over-test things. If it works for you, and you think it
1075
   should work for others, too, then commit. If your code has problems
1076
   (portability, exploits compiler bugs, unusual environment etc) they will be
1077
   reported and eventually fixed.
1078
@item 
1079
   Do not commit unrelated changes together, split them into self-contained
1080
   pieces.
1081
@item
1082
   Do not change behavior of the program (renaming options etc) without
1083
   first discussing it on the ffmpeg-devel mailing list. Do not remove
1084
   functionality from the code. Just improve!
1085
   
1086
   Note: Redundant code can be removed
1087
@item
1088
   Do not commit changes to the build system (Makefiles, configure script)
1089
   which change behavior, defaults etc, without asking first. The same
1090
   applies to compiler warning fixes, trivial looking fixes and to code
1091
   maintained by other developers. We usually have a reason for doing things
1092
   the way we do. Send your changes as patches to the ffmpeg-devel mailing
1093
   list, and if the code maintainers say OK, you may commit. This does not
1094
   apply to files you wrote and/or maintain.
1095
@item
1096
   We refuse source indentation and other cosmetic changes if they are mixed
1097
   with functional changes, such commits will be rejected and removed. Every
1098
   developer has his own indentation style, you should not change it. Of course
1099
   if you (re)write something, you can use your own style, even though we would
1100
   prefer if the indentation throughout ffmpeg would be consistent (Many projects
1101
   force a given indentation style - we don't.) If you really need to make
1102
   indentation changes (try to avoid this), separate them strictly from real
1103
   changes.
1104

    
1105
   NOTE: If you had to put if()@{ .. @} over a large (> 5 lines) chunk of code,
1106
   then either do NOT change the indentation of the inner part within (don't 
1107
   move it to the right)! or do so in a separate commit
1108
@item
1109
   Always fill out the commit log message. Describe in a few lines what you
1110
   changed and why. You can refer to mailing list postings if you fix a
1111
   particular bug. Comments such as "fixed!" or "Changed it." are unacceptable.
1112
@item
1113
   If you apply a patch by someone else, include the name and email address in
1114
   the CVS log message. Since the ffmpeg-cvslog mailing list is publicly
1115
   archived you should add some SPAM protection to the email address. Send an
1116
   answer to ffmpeg-devel (or wherever you got the patch from) saying that
1117
   you applied the patch.
1118
@item
1119
   Do NOT commit to code actively maintained by others without permission. Send
1120
   a patch to ffmpeg-devel instead.
1121
@item
1122
    Subscribe to the ffmpeg-cvslog mailing list. The diffs of all CVS commits
1123
    are sent there and reviewed by all the other developers. Bugs and possible
1124
    improvements or general questions regarding commits are discussed there. We
1125
    expect you to react if problems with your code are uncovered.
1126
@item
1127
    Update the documentation if you change behavior or add features. If you are
1128
    unsure how best to do this, send a patch to ffmpeg-devel, the documentation
1129
    maintainer(s) will review and commit your stuff.
1130
@item
1131
    Revert a commit ONLY in case of a big blunder like committing something not
1132
    intended to be committed or committing a wrong file, the wrong version of a
1133
    patch, CVS policy violation or broken code and you are going to recommit the
1134
    right thing immediately.
1135

    
1136
    Never revert changes made a long time ago or buggy code. Fix it in the
1137
    normal way instead.
1138
@item
1139
    Never write to not allocated memory, never write over the end of arrays, 
1140
    always check values read from some untrusted source before using them as index
1141
    into an array or otherwise risky things.
1142
@end enumerate
1143

    
1144
We think our rules are not too hard. If you have comments, contact us.
1145

    
1146
Note, these rules are mostly borrowed from the MPlayer project.
1147

    
1148
@subsection Renaming/moving files or content of files
1149
  You CANNOT do that. Post a request for such a change to the mailing list
1150
  Do NOT remove & readd a file - it will kill the changelog!!!!
1151

    
1152
@section Submitting patches
1153

    
1154
First, (@pxref{Coding Rules}) above if you didn't yet.
1155

    
1156
When you submit your patch, try to send a unified diff (diff '-up'
1157
option). I cannot read other diffs :-)
1158

    
1159
Also please do not submit patches which contain several unrelated changes.
1160
Split them into individual self-contained patches; this makes reviewing 
1161
them much easier.
1162

    
1163
Run the regression tests before submitting a patch so that you can
1164
verify that there are no big problems.
1165

    
1166
Patches should be posted as base64 encoded attachments (or any other
1167
encoding which ensures that the patch wont be trashed during 
1168
transmission) to the ffmpeg-devel mailing list, see 
1169
@url{http://www1.mplayerhq.hu/mailman/listinfo/ffmpeg-devel}
1170

    
1171
It also helps quite a bit if you tell us what the patch does (for example
1172
'replaces lrint by lrintf') , and why (for example '*bsd isn't C99 compliant
1173
and has no lrint()')
1174

    
1175
We reply to all patches submitted and either apply or reject with some
1176
explanation why, but sometimes we are quite busy so it can take a week or 2
1177

    
1178
@section Regression tests
1179

    
1180
Before submitting a patch (or committing with CVS), you should at least
1181
test that you did not break anything.
1182

    
1183
The regression test build a synthetic video stream and a synthetic
1184
audio stream. Then these are encoded then decoded with all codecs or
1185
formats. The CRC (or MD5) of each generated file is recorded in a
1186
result file. Then a 'diff' is launched with the reference results and
1187
the result file.
1188

    
1189
The regression test then goes on to test the ffserver code with a 
1190
limited set of streams. It is important that this step runs correctly
1191
as well.
1192

    
1193
Run 'make test' to test all the codecs and formats.
1194

    
1195
Run 'make fulltest' to test all the codecs, formats and ffserver.
1196

    
1197
[Of course, some patches may change the regression tests results. In
1198
this case, the regression tests reference results shall be modified
1199
accordingly].
1200

    
1201
@bye