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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 grab video and audio from devices given that you specify the input
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format and device.
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@example
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ffmpeg -f audio_device -i /dev/dsp -f video4linux2 -i /dev/video0 /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 X11 grabbing
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FFmpeg can grab the X11 display.
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@example
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ffmpeg -f x11grab -s cif -i :0.0 /tmp/out.mpg
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@end example
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0.0 is display.screen number of your X11 server, same as
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the DISPLAY environment variable.
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@example
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ffmpeg -f x11grab -s cif -i :0.0+10,20 /tmp/out.mpg
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@end example
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0.0 is display.screen number of your X11 server, same as the DISPLAY environment
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variable. 10 is the x-offset and 20 the y-offset for the grabbing.
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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 64k /tmp/a.mp2 -ab 128k /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 800k -g 300 -bf 2 -acodec libmp3lame -ab 128k 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-libmp3lame} 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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As a general rule, options are applied to the next specified
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file. Therefore, order is important, and you can have the same
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option on the command line multiple times. Each occurrence is
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then applied to the next input or output file.
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* To set the video bitrate of the output file to 64kbit/s:
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@example
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ffmpeg -i input.avi -b 64k output.avi
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@end example
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* To force the frame rate of the input and output file to 24 fps:
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@example
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ffmpeg -r 24 -i input.avi output.avi
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@end example
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* To force the frame rate of the output file to 24 fps:
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@example
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ffmpeg -i input.avi -r 24 output.avi
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@end example
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* To force the frame rate of input file to 1 fps and the output file to 24 fps:
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@example
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ffmpeg -r 1 -i input.avi -r 24 output.avi
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@end example
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The format option may be needed for raw input 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 -version
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Show version.
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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 -fs limit_size
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Set the file size limit.
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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 -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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@item -title string
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Set the title.
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@item -timestamp time
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Set the timestamp.
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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 -album string
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Set the album.
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@item -track number
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Set the track.
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@item -year number
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Set the year.
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@item -v verbose
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Control amount of logging.
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@item -target type
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Specify target file type ("vcd", "svcd", "dvd", "dv", "dv50", "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 -dframes number
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Set the number of data frames to record.
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@item -scodec codec
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Force subtitle codec ('copy' to copy stream).
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@item -newsubtitle
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Add a new subtitle stream to the current output stream.
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@item -slang code
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Set the ISO 639 language code (3 letters) of the current subtitle stream.
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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 bit/s (default = 200 kb/s).
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@item -vframes number
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Set the number of video frames to record.
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@item -r fps
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Set frame rate (Hz value, fraction or abbreviation), (default = 25).
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@item -s size
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Set frame size. The format is @samp{wxh} (ffserver default = 160x128, ffmpeg default = same as source).
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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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@item qqvga
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160x120
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@item qvga
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320x240
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@item vga
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640x480
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@item svga
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800x600
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@item xga
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1024x768
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@item uxga
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1600x1200
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@item qxga
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2048x1536
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@item sxga
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1280x1024
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@item qsxga
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2560x2048
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@item hsxga
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5120x4096
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@item wvga
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852x480
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@item wxga
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1366x768
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@item wsxga
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1600x1024
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@item wuxga
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1920x1200
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@item woxga
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2560x1600
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@item wqsxga
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3200x2048
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@item wquxga
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3840x2400
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@item whsxga
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6400x4096
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@item whuxga
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7680x4800
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@item cga
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320x200
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@item ega
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640x350
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@item hd480
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852x480
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@item hd720
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1280x720
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@item hd1080
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1920x1080
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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 bit/s).
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@item -maxrate bitrate
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Set max video bitrate tolerance (in bit/s).
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@item -minrate bitrate
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Set min video bitrate tolerance (in bit/s).
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@item -bufsize size
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Set rate control buffer size (in bits).
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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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@item -newvideo
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Add a new video stream to the current output stream.
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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 -pix_fmt format
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Set pixel format. Use 'list' as parameter to show all the supported
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pixel formats.
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@item -sws_flags flags
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Set SwScaler flags (only available when compiled with SwScaler support).
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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 -vdt n
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Discard threshold.
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@item -qscale q
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Use fixed video quantizer scale (VBR).
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@item -qmin q
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minimum video quantizer scale (VBR)
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@item -qmax q
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maximum video quantizer scale (VBR)
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@item -qdiff q
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maximum difference between the quantizer scales (VBR)
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@item -qblur blur
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video quantizer scale blur (VBR)
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@item -qcomp compression
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video quantizer scale compression (VBR)
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@item -lmin lambda
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minimum video lagrange factor (VBR)
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@item -lmax lambda
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max video lagrange factor (VBR)
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@item -mblmin lambda
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minimum macroblock quantizer scale (VBR)
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@item -mblmax lambda
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maximum macroblock quantizer scale (VBR)
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These four options (lmin, lmax, mblmin, mblmax) use 'lambda' units,
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but you may use the QP2LAMBDA constant to easily convert from 'q' units:
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@example
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ffmpeg -i src.ext -lmax 21*QP2LAMBDA dst.ext
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@end example
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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 -ilme
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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 -vstats_file file
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Dump video coding statistics to @var{file}.
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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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@item -top n
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top=1/bottom=0/auto=-1 field first
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@item -dc precision
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Intra_dc_precision.
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@item -vtag fourcc/tag
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Force video tag/fourcc.
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@item -qphist
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Show QP histogram.
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@item -vbsf bitstream filter
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Bitstream filters available are "dump_extra", "remove_extra", "noise".
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@end table
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@section Audio Options
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@table @option
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@item -aframes number
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Set the number of audio frames to record.
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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 bit/s (default = 64k).
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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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@item -newaudio
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Add a new audio track to the output file. If you want to specify parameters,
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do so before @code{-newaudio} (@code{-acodec}, @code{-ab}, etc..).
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Mapping will be done automatically, if the number of output streams is equal to
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the number of input streams, else it will pick the first one that matches. You
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can override the mapping using @code{-map} as usual.
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Example:
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@example
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ffmpeg -i file.mpg -vcodec copy -acodec ac3 -ab 384k test.mpg -acodec mp2 -ab 192k -newaudio
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@end example
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@item -alang code
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Set the ISO 639 language code (3 letters) of the current audio stream.
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@end table
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@section Advanced Audio options:
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@table @option
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@item -atag fourcc/tag
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Force audio tag/fourcc.
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@item -absf bitstream filter
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Bitstream filters available are "dump_extra", "remove_extra", "noise", "mp3comp", "mp3decomp".
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@end table
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@section Subtitle options:
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@table @option
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@item -scodec codec
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Force subtitle codec ('copy' to copy stream).
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@item -newsubtitle
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Add a new subtitle stream to the current output stream.
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@item -slang code
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Set the ISO 639 language code (3 letters) of the current subtitle stream.
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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 -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 -isync
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Synchronize read on input.
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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 input stream id[:input stream id]
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Set stream mapping from input streams to output streams.
676
Just enumerate the input streams in the order you want them in the output.
677
[input stream id] sets the (input) stream to sync against.
678
@item -map_meta_data outfile:infile
679
Set meta data information of outfile from infile.
680
@item -debug
681
Print specific debug info.
682
@item -benchmark
683
Add timings for benchmarking.
684
@item -dump
685
Dump each input packet.
686
@item -hex
687
When dumping packets, also dump the payload.
688
@item -bitexact
689
Only use bit exact algorithms (for codec testing).
690
@item -ps size
691
Set packet size in bits.
692
@item -re
693
Read input at native frame rate. Mainly used to simulate a grab device.
694
@item -loop_input
695
Loop over the input stream. Currently it works only for image
696
streams. This option is used for automatic FFserver testing.
697
@item -loop_output number_of_times
698
Repeatedly loop output for formats that support looping such as animated GIF
699
(0 will loop the output infinitely).
700
@item -threads count
701
Thread count.
702
@item -vsync parameter
703
Video sync method. Video will be stretched/squeezed to match the timestamps,
704
it is done by duplicating and dropping frames. With -map you can select from
705
which stream the timestamps should be taken. You can leave either video or
706
audio unchanged and sync the remaining stream(s) to the unchanged one.
707
@item -async samples_per_second
708
Audio sync method. "Stretches/squeezes" the audio stream to match the timestamps,
709
the parameter is the maximum samples per second by which the audio is changed.
710
-async 1 is a special case where only the start of the audio stream is corrected
711
without any later correction.
712
@item -copyts
713
Copy timestamps from input to output.
714
@item -shortest
715
Finish encoding when the shortest input stream ends.
716
@item -dts_delta_threshold
717
Timestamp discontinuity delta threshold.
718
@item -muxdelay seconds
719
Set the maximum demux-decode delay.
720
@item -muxpreload seconds
721
Set the initial demux-decode delay.
722
@end table
723

    
724
@node FFmpeg formula evaluator
725
@section FFmpeg formula evaluator
726

    
727
When evaluating a rate control string, FFmpeg uses an internal formula
728
evaluator.
729

    
730
The following binary operators are available: @code{+}, @code{-},
731
@code{*}, @code{/}, @code{^}.
732

    
733
The following unary operators are available: @code{+}, @code{-},
734
@code{(...)}.
735

    
736
The following functions are available:
737
@table @var
738
@item sinh(x)
739
@item cosh(x)
740
@item tanh(x)
741
@item sin(x)
742
@item cos(x)
743
@item tan(x)
744
@item exp(x)
745
@item log(x)
746
@item squish(x)
747
@item gauss(x)
748
@item abs(x)
749
@item max(x, y)
750
@item min(x, y)
751
@item gt(x, y)
752
@item lt(x, y)
753
@item eq(x, y)
754
@item bits2qp(bits)
755
@item qp2bits(qp)
756
@end table
757

    
758
The following constants are available:
759
@table @var
760
@item PI
761
@item E
762
@item iTex
763
@item pTex
764
@item tex
765
@item mv
766
@item fCode
767
@item iCount
768
@item mcVar
769
@item var
770
@item isI
771
@item isP
772
@item isB
773
@item avgQP
774
@item qComp
775
@item avgIITex
776
@item avgPITex
777
@item avgPPTex
778
@item avgBPTex
779
@item avgTex
780
@end table
781

    
782
@c man end
783

    
784
@ignore
785

    
786
@setfilename ffmpeg
787
@settitle FFmpeg video converter
788

    
789
@c man begin SEEALSO
790
ffserver(1), ffplay(1) and the HTML documentation of @file{ffmpeg}.
791
@c man end
792

    
793
@c man begin AUTHOR
794
Fabrice Bellard
795
@c man end
796

    
797
@end ignore
798

    
799
@section Protocols
800

    
801
The filename can be @file{-} to read from standard input or to write
802
to standard output.
803

    
804
FFmpeg also handles many protocols specified with an URL syntax.
805

    
806
Use 'ffmpeg -formats' to see a list of the supported protocols.
807

    
808
The protocol @code{http:} is currently used only to communicate with
809
FFserver (see the FFserver documentation). When FFmpeg will be a
810
video player it will also be used for streaming :-)
811

    
812
@chapter Tips
813

    
814
@itemize
815
@item For streaming at very low bitrate application, use a low frame rate
816
and a small GOP size. This is especially true for RealVideo where
817
the Linux player does not seem to be very fast, so it can miss
818
frames. An example is:
819

    
820
@example
821
ffmpeg -g 3 -r 3 -t 10 -b 50k -s qcif -f rv10 /tmp/b.rm
822
@end example
823

    
824
@item  The parameter 'q' which is displayed while encoding is the current
825
quantizer. The value 1 indicates that a very good quality could
826
be achieved. The value 31 indicates the worst quality. If q=31 appears
827
too often, it means that the encoder cannot compress enough to meet
828
your bitrate. You must either increase the bitrate, decrease the
829
frame rate or decrease the frame size.
830

    
831
@item If your computer is not fast enough, you can speed up the
832
compression at the expense of the compression ratio. You can use
833
'-me zero' to speed up motion estimation, and '-intra' to disable
834
motion estimation completely (you have only I-frames, which means it
835
is about as good as JPEG compression).
836

    
837
@item To have very low audio bitrates, reduce the sampling frequency
838
(down to 22050 kHz for MPEG audio, 22050 or 11025 for AC3).
839

    
840
@item To have a constant quality (but a variable bitrate), use the option
841
'-qscale n' when 'n' is between 1 (excellent quality) and 31 (worst
842
quality).
843

    
844
@item When converting video files, you can use the '-sameq' option which
845
uses the same quality factor in the encoder as in the decoder.
846
It allows almost lossless encoding.
847

    
848
@end itemize
849

    
850

    
851
@chapter external libraries
852

    
853
FFmpeg can be hooked up with a number of external libraries to add support
854
for more formats. None of them are used by default, their use has to be
855
explicitly requested by passing the appropriate flags to @file{./configure}.
856

    
857
@section AMR
858

    
859
AMR comes in two different flavors, WB and NB. FFmpeg can make use of the
860
AMR WB (floating-point mode) and the AMR NB (floating-point mode) reference
861
decoders and encoders.
862

    
863
Go to @url{http://www.penguin.cz/~utx/amr} and follow the instructions for
864
installing the libraries. Then pass @code{--enable-libamr-nb} and/or
865
@code{--enable-libamr-wb} to configure to enable the libraries.
866

    
867

    
868
@chapter Supported File Formats and Codecs
869

    
870
You can use the @code{-formats} option to have an exhaustive list.
871

    
872
@section File Formats
873

    
874
FFmpeg supports the following file formats through the @code{libavformat}
875
library:
876

    
877
@multitable @columnfractions .4 .1 .1 .4
878
@item Supported File Format @tab Encoding @tab Decoding @tab Comments
879
@item MPEG audio @tab X @tab X
880
@item MPEG-1 systems @tab X  @tab  X
881
@tab muxed audio and video
882
@item MPEG-2 PS @tab X  @tab  X
883
@tab also known as @code{VOB} file
884
@item MPEG-2 TS @tab    @tab  X
885
@tab also known as DVB Transport Stream
886
@item ASF@tab X @tab X
887
@item AVI@tab X @tab X
888
@item WAV@tab X @tab X
889
@item Macromedia Flash@tab X @tab X
890
@tab Only embedded audio is decoded.
891
@item FLV              @tab  X @tab X
892
@tab Macromedia Flash video files
893
@item Real Audio and Video @tab X @tab X
894
@item Raw AC3 @tab X  @tab  X
895
@item Raw MJPEG @tab X  @tab  X
896
@item Raw MPEG video @tab X  @tab  X
897
@item Raw PCM8/16 bits, mulaw/Alaw@tab X  @tab  X
898
@item Raw CRI ADX audio @tab X  @tab  X
899
@item Raw Shorten audio @tab    @tab  X
900
@item SUN AU format @tab X  @tab  X
901
@item NUT @tab X @tab X @tab NUT Open Container Format
902
@item QuickTime        @tab X @tab  X
903
@item MPEG-4           @tab X @tab  X
904
@tab MPEG-4 is a variant of QuickTime.
905
@item Raw MPEG4 video  @tab  X @tab  X
906
@item DV               @tab  X @tab  X
907
@item 4xm              @tab    @tab X
908
@tab 4X Technologies format, used in some games.
909
@item Playstation STR  @tab    @tab X
910
@item Id RoQ           @tab X  @tab X
911
@tab Used in Quake III, Jedi Knight 2, other computer games.
912
@item Interplay MVE    @tab    @tab X
913
@tab Format used in various Interplay computer games.
914
@item WC3 Movie        @tab    @tab X
915
@tab Multimedia format used in Origin's Wing Commander III computer game.
916
@item Sega FILM/CPK    @tab    @tab X
917
@tab Used in many Sega Saturn console games.
918
@item Westwood Studios VQA/AUD  @tab    @tab X
919
@tab Multimedia formats used in Westwood Studios games.
920
@item Id Cinematic (.cin) @tab    @tab X
921
@tab Used in Quake II.
922
@item FLIC format      @tab    @tab X
923
@tab .fli/.flc files
924
@item Sierra VMD       @tab    @tab X
925
@tab Used in Sierra CD-ROM games.
926
@item Sierra Online    @tab    @tab X
927
@tab .sol files used in Sierra Online games.
928
@item Matroska         @tab    @tab X
929
@item Electronic Arts Multimedia    @tab    @tab X
930
@tab Used in various EA games; files have extensions like WVE and UV2.
931
@item Nullsoft Video (NSV) format @tab    @tab X
932
@item ADTS AAC audio @tab X @tab X
933
@item Creative VOC @tab X @tab X @tab Created for the Sound Blaster Pro.
934
@item American Laser Games MM  @tab    @tab X
935
@tab Multimedia format used in games like Mad Dog McCree
936
@item AVS @tab    @tab X
937
@tab Multimedia format used by the Creature Shock game.
938
@item Smacker @tab    @tab X
939
@tab Multimedia format used by many games.
940
@item GXF @tab  X @tab X
941
@tab General eXchange Format SMPTE 360M, used by Thomson Grass Valley playout servers.
942
@item CIN @tab    @tab X
943
@tab Multimedia format used by Delphine Software games.
944
@item MXF @tab    @tab X
945
@tab Material eXchange Format SMPTE 377M, used by D-Cinema, broadcast industry.
946
@item SEQ @tab    @tab X
947
@tab Tiertex .seq files used in the DOS CDROM version of the game Flashback.
948
@item DXA @tab    @tab X
949
@tab This format is used in non-Windows version of Feeble Files game and
950
different game cutscenes repacked for use with ScummVM.
951
@item THP @tab    @tab X
952
@tab Used on the Nintendo GameCube.
953
@item C93 @tab    @tab X
954
@tab Used in the game Cyberia from Interplay.
955
@item Bethsoft VID @tab    @tab X
956
@tab Used in some games from Bethesda Softworks.
957
@item CRYO APC @tab    @tab X
958
@tab Audio format used in some games by CRYO Interactive Entertainment.
959
@end multitable
960

    
961
@code{X} means that encoding (resp. decoding) is supported.
962

    
963
@section Image Formats
964

    
965
FFmpeg can read and write images for each frame of a video sequence. The
966
following image formats are supported:
967

    
968
@multitable @columnfractions .4 .1 .1 .4
969
@item Supported Image Format @tab Encoding @tab Decoding @tab Comments
970
@item PGM, PPM     @tab X @tab X
971
@item PAM          @tab X @tab X @tab PAM is a PNM extension with alpha support.
972
@item PGMYUV       @tab X @tab X @tab PGM with U and V components in YUV 4:2:0
973
@item JPEG         @tab X @tab X @tab Progressive JPEG is not supported.
974
@item .Y.U.V       @tab X @tab X @tab one raw file per component
975
@item animated GIF @tab X @tab X @tab Only uncompressed GIFs are generated.
976
@item PNG          @tab X @tab X @tab 2 bit and 4 bit/pixel not supported yet.
977
@item Targa        @tab   @tab X @tab Targa (.TGA) image format.
978
@item TIFF         @tab X @tab X @tab YUV, JPEG and some extension is not supported yet.
979
@item SGI          @tab X @tab X @tab SGI RGB image format
980
@item PTX          @tab   @tab X @tab V.Flash PTX format
981
@end multitable
982

    
983
@code{X} means that encoding (resp. decoding) is supported.
984

    
985
@section Video Codecs
986

    
987
@multitable @columnfractions .4 .1 .1 .4
988
@item Supported Codec @tab Encoding @tab Decoding @tab Comments
989
@item MPEG-1 video           @tab  X  @tab  X
990
@item MPEG-2 video           @tab  X  @tab  X
991
@item MPEG-4                 @tab  X  @tab  X
992
@item MSMPEG4 V1             @tab  X  @tab  X
993
@item MSMPEG4 V2             @tab  X  @tab  X
994
@item MSMPEG4 V3             @tab  X  @tab  X
995
@item WMV7                   @tab  X  @tab  X
996
@item WMV8                   @tab  X  @tab  X @tab not completely working
997
@item WMV9                   @tab     @tab  X @tab not completely working
998
@item VC1                    @tab     @tab  X
999
@item H.261                  @tab  X  @tab  X
1000
@item H.263(+)               @tab  X  @tab  X @tab also known as RealVideo 1.0
1001
@item H.264                  @tab     @tab  X
1002
@item RealVideo 1.0          @tab  X  @tab  X
1003
@item RealVideo 2.0          @tab  X  @tab  X
1004
@item MJPEG                  @tab  X  @tab  X
1005
@item lossless MJPEG         @tab  X  @tab  X
1006
@item JPEG-LS                @tab  X  @tab  X @tab fourcc: MJLS, lossless and near-lossless is supported
1007
@item Apple MJPEG-B          @tab     @tab  X
1008
@item Sunplus MJPEG          @tab     @tab  X @tab fourcc: SP5X
1009
@item DV                     @tab  X  @tab  X
1010
@item HuffYUV                @tab  X  @tab  X
1011
@item FFmpeg Video 1         @tab  X  @tab  X @tab experimental lossless codec (fourcc: FFV1)
1012
@item FFmpeg Snow            @tab  X  @tab  X @tab experimental wavelet codec (fourcc: SNOW)
1013
@item Asus v1                @tab  X  @tab  X @tab fourcc: ASV1
1014
@item Asus v2                @tab  X  @tab  X @tab fourcc: ASV2
1015
@item Creative YUV           @tab     @tab  X @tab fourcc: CYUV
1016
@item Sorenson Video 1       @tab  X  @tab  X @tab fourcc: SVQ1
1017
@item Sorenson Video 3       @tab     @tab  X @tab fourcc: SVQ3
1018
@item On2 VP3                @tab     @tab  X @tab still experimental
1019
@item On2 VP5                @tab     @tab  X @tab fourcc: VP50
1020
@item On2 VP6                @tab     @tab  X @tab fourcc: VP60,VP61,VP62
1021
@item Theora                 @tab  X  @tab  X @tab still experimental
1022
@item Intel Indeo 3          @tab     @tab  X
1023
@item FLV                    @tab  X  @tab  X @tab Sorenson H.263 used in Flash
1024
@item Flash Screen Video     @tab  X  @tab  X @tab fourcc: FSV1
1025
@item ATI VCR1               @tab     @tab  X @tab fourcc: VCR1
1026
@item ATI VCR2               @tab     @tab  X @tab fourcc: VCR2
1027
@item Cirrus Logic AccuPak   @tab     @tab  X @tab fourcc: CLJR
1028
@item 4X Video               @tab     @tab  X @tab Used in certain computer games.
1029
@item Sony Playstation MDEC  @tab     @tab  X
1030
@item Id RoQ                 @tab  X  @tab  X @tab Used in Quake III, Jedi Knight 2, other computer games.
1031
@item Xan/WC3                @tab     @tab  X @tab Used in Wing Commander III .MVE files.
1032
@item Interplay Video        @tab     @tab  X @tab Used in Interplay .MVE files.
1033
@item Apple Animation        @tab     @tab  X @tab fourcc: 'rle '
1034
@item Apple Graphics         @tab     @tab  X @tab fourcc: 'smc '
1035
@item Apple Video            @tab     @tab  X @tab fourcc: rpza
1036
@item Apple QuickDraw        @tab     @tab  X @tab fourcc: qdrw
1037
@item Cinepak                @tab     @tab  X
1038
@item Microsoft RLE          @tab     @tab  X
1039
@item Microsoft Video-1      @tab     @tab  X
1040
@item Westwood VQA           @tab     @tab  X
1041
@item Id Cinematic Video     @tab     @tab  X @tab Used in Quake II.
1042
@item Planar RGB             @tab     @tab  X @tab fourcc: 8BPS
1043
@item FLIC video             @tab     @tab  X
1044
@item Duck TrueMotion v1     @tab     @tab  X @tab fourcc: DUCK
1045
@item Duck TrueMotion v2     @tab     @tab  X @tab fourcc: TM20
1046
@item VMD Video              @tab     @tab  X @tab Used in Sierra VMD files.
1047
@item MSZH                   @tab     @tab  X @tab Part of LCL
1048
@item ZLIB                   @tab  X  @tab  X @tab Part of LCL, encoder experimental
1049
@item TechSmith Camtasia     @tab     @tab  X @tab fourcc: TSCC
1050
@item IBM Ultimotion         @tab     @tab  X @tab fourcc: ULTI
1051
@item Miro VideoXL           @tab     @tab  X @tab fourcc: VIXL
1052
@item QPEG                   @tab     @tab  X @tab fourccs: QPEG, Q1.0, Q1.1
1053
@item LOCO                   @tab     @tab  X @tab
1054
@item Winnov WNV1            @tab     @tab  X @tab
1055
@item Autodesk Animator Studio Codec  @tab     @tab  X @tab fourcc: AASC
1056
@item Fraps FPS1             @tab     @tab  X @tab
1057
@item CamStudio              @tab     @tab  X @tab fourcc: CSCD
1058
@item American Laser Games Video  @tab    @tab X @tab Used in games like Mad Dog McCree
1059
@item ZMBV                   @tab   X @tab  X @tab Encoder works only on PAL8
1060
@item AVS Video              @tab     @tab  X @tab Video encoding used by the Creature Shock game.
1061
@item Smacker Video          @tab     @tab  X @tab Video encoding used in Smacker.
1062
@item RTjpeg                 @tab     @tab  X @tab Video encoding used in NuppelVideo files.
1063
@item KMVC                   @tab     @tab  X @tab Codec used in Worms games.
1064
@item VMware Video           @tab     @tab  X @tab Codec used in videos captured by VMware.
1065
@item Cin Video              @tab     @tab  X @tab Codec used in Delphine Software games.
1066
@item Tiertex Seq Video      @tab     @tab  X @tab Codec used in DOS CDROM FlashBack game.
1067
@item DXA Video              @tab     @tab  X @tab Codec originally used in Feeble Files game.
1068
@item AVID DNxHD             @tab     @tab  X @tab aka SMPTE VC3
1069
@item C93 Video              @tab     @tab  X @tab Codec used in Cyberia game.
1070
@item THP                    @tab     @tab  X @tab Used on the Nintendo GameCube.
1071
@item Bethsoft VID           @tab     @tab  X @tab Used in some games from Bethesda Softworks.
1072
@item Renderware TXD         @tab     @tab  X @tab Texture dictionaries used by the Renderware Engine.
1073
@end multitable
1074

    
1075
@code{X} means that encoding (resp. decoding) is supported.
1076

    
1077
@section Audio Codecs
1078

    
1079
@multitable @columnfractions .4 .1 .1 .1 .7
1080
@item Supported Codec @tab Encoding @tab Decoding @tab Comments
1081
@item MPEG audio layer 2     @tab  IX  @tab  IX
1082
@item MPEG audio layer 1/3   @tab IX   @tab  IX
1083
@tab MP3 encoding is supported through the external library LAME.
1084
@item AC3                    @tab  IX  @tab  IX
1085
@tab liba52 is used internally for decoding.
1086
@item Vorbis                 @tab  X   @tab  X
1087
@item WMA V1/V2              @tab X    @tab X
1088
@item AAC                    @tab X    @tab X
1089
@tab Supported through the external library libfaac/libfaad.
1090
@item Microsoft ADPCM        @tab X    @tab X
1091
@item MS IMA ADPCM           @tab X    @tab X
1092
@item QT IMA ADPCM           @tab      @tab X
1093
@item 4X IMA ADPCM           @tab      @tab X
1094
@item G.726  ADPCM           @tab X    @tab X
1095
@item Duck DK3 IMA ADPCM     @tab      @tab X
1096
@tab Used in some Sega Saturn console games.
1097
@item Duck DK4 IMA ADPCM     @tab      @tab X
1098
@tab Used in some Sega Saturn console games.
1099
@item Westwood Studios IMA ADPCM @tab      @tab X
1100
@tab Used in Westwood Studios games like Command and Conquer.
1101
@item SMJPEG IMA ADPCM       @tab      @tab X
1102
@tab Used in certain Loki game ports.
1103
@item CD-ROM XA ADPCM        @tab      @tab X
1104
@item CRI ADX ADPCM          @tab X    @tab X
1105
@tab Used in Sega Dreamcast games.
1106
@item Electronic Arts ADPCM  @tab      @tab X
1107
@tab Used in various EA titles.
1108
@item Creative ADPCM         @tab      @tab X
1109
@tab 16 -> 4, 8 -> 4, 8 -> 3, 8 -> 2
1110
@item THP ADPCM              @tab      @tab X
1111
@tab Used on the Nintendo GameCube.
1112
@item RA144                  @tab      @tab X
1113
@tab Real 14400 bit/s codec
1114
@item RA288                  @tab      @tab X
1115
@tab Real 28800 bit/s codec
1116
@item RADnet                 @tab X    @tab IX
1117
@tab Real low bitrate AC3 codec, liba52 is used for decoding.
1118
@item AMR-NB                 @tab X    @tab X
1119
@tab Supported through an external library.
1120
@item AMR-WB                 @tab X    @tab X
1121
@tab Supported through an external library.
1122
@item DV audio               @tab      @tab X
1123
@item Id RoQ DPCM            @tab X    @tab X
1124
@tab Used in Quake III, Jedi Knight 2, other computer games.
1125
@item Interplay MVE DPCM     @tab      @tab X
1126
@tab Used in various Interplay computer games.
1127
@item Xan DPCM               @tab      @tab X
1128
@tab Used in Origin's Wing Commander IV AVI files.
1129
@item Sierra Online DPCM     @tab      @tab X
1130
@tab Used in Sierra Online game audio files.
1131
@item Apple MACE 3           @tab      @tab X
1132
@item Apple MACE 6           @tab      @tab X
1133
@item FLAC lossless audio    @tab X    @tab X
1134
@item Shorten lossless audio @tab      @tab X
1135
@item Apple lossless audio   @tab      @tab X
1136
@tab QuickTime fourcc 'alac'
1137
@item FFmpeg Sonic           @tab X    @tab X
1138
@tab experimental lossy/lossless codec
1139
@item Qdesign QDM2           @tab      @tab X
1140
@tab there are still some distortions
1141
@item Real COOK              @tab      @tab X
1142
@tab All versions except 5.1 are supported
1143
@item DSP Group TrueSpeech   @tab      @tab X
1144
@item True Audio (TTA)       @tab      @tab X
1145
@item Smacker Audio          @tab      @tab X
1146
@item WavPack Audio          @tab      @tab X
1147
@item Cin Audio              @tab      @tab X
1148
@tab Codec used in Delphine Software games.
1149
@item Intel Music Coder      @tab      @tab X
1150
@item Musepack               @tab      @tab X
1151
@tab Only SV7 is supported
1152
@item DT$ Coherent Audio     @tab      @tab X
1153
@item ATRAC 3                @tab      @tab X
1154
@end multitable
1155

    
1156
@code{X} means that encoding (resp. decoding) is supported.
1157

    
1158
@code{I} means that an integer-only version is available, too (ensures high
1159
performance on systems without hardware floating point support).
1160

    
1161
@chapter Platform Specific information
1162

    
1163
@section BSD
1164

    
1165
BSD make will not build FFmpeg, you need to install and use GNU Make
1166
(@file{gmake}).
1167

    
1168
@section Windows
1169

    
1170
To get help and instructions for using FFmpeg under Windows, check out
1171
the FFmpeg Windows Help Forum at
1172
@url{http://arrozcru.no-ip.org/ffmpeg/}.
1173

    
1174
@subsection Native Windows compilation
1175

    
1176
@itemize
1177
@item Install the current versions of MSYS and MinGW from
1178
@url{http://www.mingw.org/}. You can find detailed installation
1179
instructions in the download section and the FAQ.
1180

    
1181
NOTE: Use at least bash 3.1. Older versions are known to be failing on the
1182
configure script.
1183

    
1184
@item If you want to test the FFplay, also download
1185
the MinGW development library of SDL 1.2.x
1186
(@file{SDL-devel-1.2.x-mingw32.tar.gz}) from
1187
@url{http://www.libsdl.org}. Unpack it in a temporary directory, and
1188
unpack the archive @file{i386-mingw32msvc.tar.gz} in the MinGW tool
1189
directory. Edit the @file{sdl-config} script so that it gives the
1190
correct SDL directory when invoked.
1191

    
1192
@item Extract the current version of FFmpeg.
1193

    
1194
@item Start the MSYS shell (file @file{msys.bat}).
1195

    
1196
@item Change to the FFmpeg directory and follow
1197
 the instructions of how to compile FFmpeg (file
1198
@file{INSTALL}). Usually, launching @file{./configure} and @file{make}
1199
suffices. If you have problems using SDL, verify that
1200
@file{sdl-config} can be launched from the MSYS command line.
1201

    
1202
@item You can install FFmpeg in @file{Program Files/FFmpeg} by typing
1203
@file{make install}. Do not forget to copy @file{SDL.dll} to the place
1204
you launch @file{ffplay} from.
1205

    
1206
@end itemize
1207

    
1208
Notes:
1209
@itemize
1210

    
1211
@item The target @file{make wininstaller} can be used to create a
1212
Nullsoft based Windows installer for FFmpeg and FFplay. @file{SDL.dll}
1213
must be copied to the FFmpeg directory in order to build the
1214
installer.
1215

    
1216
@item By using @code{./configure --enable-shared} when configuring FFmpeg,
1217
you can build @file{avcodec.dll} and @file{avformat.dll}. With
1218
@code{make install} you install the FFmpeg DLLs and the associated
1219
headers in @file{Program Files/FFmpeg}.
1220

    
1221
@item Visual C++ compatibility: If you used @code{./configure --enable-shared}
1222
when configuring FFmpeg, FFmpeg tries to use the Microsoft Visual
1223
C++ @code{lib} tool to build @code{avcodec.lib} and
1224
@code{avformat.lib}. With these libraries you can link your Visual C++
1225
code directly with the FFmpeg DLLs (see below).
1226

    
1227
@end itemize
1228

    
1229
@subsection Visual C++ compatibility
1230

    
1231
FFmpeg will not compile under Visual C++ -- and it has too many
1232
dependencies on the GCC compiler to make a port viable. However,
1233
if you want to use the FFmpeg libraries in your own applications,
1234
you can still compile those applications using Visual C++. An
1235
important restriction to this is that you have to use the
1236
dynamically linked versions of the FFmpeg libraries (i.e. the
1237
DLLs), and you have to make sure that Visual-C++-compatible
1238
import libraries are created during the FFmpeg build process.
1239

    
1240
This description of how to use the FFmpeg libraries with Visual C++ is
1241
based on Visual C++ 2005 Express Edition Beta 2. If you have a different
1242
version, you might have to modify the procedures slightly.
1243

    
1244
Here are the step-by-step instructions for building the FFmpeg libraries
1245
so they can be used with Visual C++:
1246

    
1247
@enumerate
1248

    
1249
@item Install Visual C++ (if you have not done so already).
1250

    
1251
@item Install MinGW and MSYS as described above.
1252

    
1253
@item Add a call to @file{vcvars32.bat} (which sets up the environment
1254
variables for the Visual C++ tools) as the first line of
1255
@file{msys.bat}. The standard location for @file{vcvars32.bat} is
1256
@file{C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat},
1257
and the standard location for @file{msys.bat} is
1258
@file{C:\msys\1.0\msys.bat}. If this corresponds to your setup, add the
1259
following line as the first line of @file{msys.bat}:
1260

    
1261
@code{call "C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat"}
1262

    
1263
@item Start the MSYS shell (file @file{msys.bat}) and type @code{link.exe}.
1264
If you get a help message with the command line options of @code{link.exe},
1265
this means your environment variables are set up correctly, the
1266
Microsoft linker is on the path and will be used by FFmpeg to
1267
create Visual-C++-compatible import libraries.
1268

    
1269
@item Extract the current version of FFmpeg and change to the FFmpeg directory.
1270

    
1271
@item Type the command
1272
@code{./configure --enable-shared --disable-static --enable-memalign-hack}
1273
to configure and, if that did not produce any errors,
1274
type @code{make} to build FFmpeg.
1275

    
1276
@item The subdirectories @file{libavformat}, @file{libavcodec}, and
1277
@file{libavutil} should now contain the files @file{avformat.dll},
1278
@file{avformat.lib}, @file{avcodec.dll}, @file{avcodec.lib},
1279
@file{avutil.dll}, and @file{avutil.lib}, respectively. Copy the three
1280
DLLs to your System32 directory (typically @file{C:\Windows\System32}).
1281

    
1282
@end enumerate
1283

    
1284
And here is how to use these libraries with Visual C++:
1285

    
1286
@enumerate
1287

    
1288
@item Create a new console application ("File / New / Project") and then
1289
select "Win32 Console Application". On the appropriate page of the
1290
Application Wizard, uncheck the "Precompiled headers" option.
1291

    
1292
@item Write the source code for your application, or, for testing, just
1293
copy the code from an existing sample application into the source file
1294
that Visual C++ has already created for you. (Note that your source
1295
filehas to have a @code{.cpp} extension; otherwise, Visual C++ will not
1296
compile the FFmpeg headers correctly because in C mode, it does not
1297
recognize the @code{inline} keyword.)  For example, you can copy
1298
@file{output_example.c} from the FFmpeg distribution (but you will
1299
have to make minor modifications so the code will compile under
1300
C++, see below).
1301

    
1302
@item Open the "Project / Properties" dialog box. In the "Configuration"
1303
combo box, select "All Configurations" so that the changes you make will
1304
affect both debug and release builds. In the tree view on the left hand
1305
side, select "C/C++ / General", then edit the "Additional Include
1306
Directories" setting to contain the complete paths to the
1307
@file{libavformat}, @file{libavcodec}, and @file{libavutil}
1308
subdirectories of your FFmpeg directory. Note that the directories have
1309
to be separated using semicolons. Now select "Linker / General" from the
1310
tree view and edit the "Additional Library Directories" setting to
1311
contain the same three directories.
1312

    
1313
@item Still in the "Project / Properties" dialog box, select "Linker / Input"
1314
from the tree view, then add the files @file{avformat.lib},
1315
@file{avcodec.lib}, and @file{avutil.lib} to the end of the "Additional
1316
Dependencies". Note that the names of the libraries have to be separated
1317
using spaces.
1318

    
1319
@item Now, select "C/C++ / Code Generation" from the tree view. Select
1320
"Debug" in the "Configuration" combo box. Make sure that "Runtime
1321
Library" is set to "Multi-threaded Debug DLL". Then, select "Release" in
1322
the "Configuration" combo box and make sure that "Runtime Library" is
1323
set to "Multi-threaded DLL".
1324

    
1325
@item Click "OK" to close the "Project / Properties" dialog box and build
1326
the application. Hopefully, it should compile and run cleanly. If you
1327
used @file{output_example.c} as your sample application, you will get a
1328
few compiler errors, but they are easy to fix. The first type of error
1329
occurs because Visual C++ does not allow an @code{int} to be converted to
1330
an @code{enum} without a cast. To solve the problem, insert the required
1331
casts (this error occurs once for a @code{CodecID} and once for a
1332
@code{CodecType}).  The second type of error occurs because C++ requires
1333
the return value of @code{malloc} to be cast to the exact type of the
1334
pointer it is being assigned to. Visual C++ will complain that, for
1335
example, @code{(void *)} is being assigned to @code{(uint8_t *)} without
1336
an explicit cast. So insert an explicit cast in these places to silence
1337
the compiler. The third type of error occurs because the @code{snprintf}
1338
library function is called @code{_snprintf} under Visual C++.  So just
1339
add an underscore to fix the problem. With these changes,
1340
@file{output_example.c} should compile under Visual C++, and the
1341
resulting executable should produce valid video files.
1342

    
1343
@end enumerate
1344

    
1345
@subsection Cross compilation for Windows with Linux
1346

    
1347
You must use the MinGW cross compilation tools available at
1348
@url{http://www.mingw.org/}.
1349

    
1350
Then configure FFmpeg with the following options:
1351
@example
1352
./configure --target-os=mingw32 --cross-prefix=i386-mingw32msvc-
1353
@end example
1354
(you can change the cross-prefix according to the prefix chosen for the
1355
MinGW tools).
1356

    
1357
Then you can easily test FFmpeg with Wine
1358
(@url{http://www.winehq.com/}).
1359

    
1360
@subsection Compilation under Cygwin
1361

    
1362
Cygwin works very much like Unix.
1363

    
1364
Just install your Cygwin with all the "Base" packages, plus the
1365
following "Devel" ones:
1366
@example
1367
binutils, gcc-core, make, subversion
1368
@end example
1369

    
1370
Do not install binutils-20060709-1 (they are buggy on shared builds);
1371
use binutils-20050610-1 instead.
1372

    
1373
Then run
1374

    
1375
@example
1376
./configure --enable-static --disable-shared
1377
@end example
1378

    
1379
to make a static build or
1380

    
1381
@example
1382
./configure --enable-shared --disable-static
1383
@end example
1384

    
1385
to build shared libraries.
1386

    
1387
If you want to build FFmpeg with additional libraries, download Cygwin
1388
"Devel" packages for Ogg and Vorbis from any Cygwin packages repository
1389
and/or SDL, xvid, faac, faad2 packages from Cygwin Ports,
1390
(@url{http://cygwinports.dotsrc.org/}).
1391

    
1392
@subsection Crosscompilation for Windows under Cygwin
1393

    
1394
With Cygwin you can create Windows binaries that do not need the cygwin1.dll.
1395

    
1396
Just install your Cygwin as explained before, plus these additional
1397
"Devel" packages:
1398
@example
1399
gcc-mingw-core, mingw-runtime, mingw-zlib
1400
@end example
1401

    
1402
and add some special flags to your configure invocation.
1403

    
1404
For a static build run
1405
@example
1406
./configure --target-os=mingw32 --enable-memalign-hack --enable-static --disable-shared --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
1407
@end example
1408

    
1409
and for a build with shared libraries
1410
@example
1411
./configure --target-os=mingw32 --enable-memalign-hack --enable-shared --disable-static --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
1412
@end example
1413

    
1414
@section BeOS
1415

    
1416
The configure script should guess the configuration itself.
1417
Networking support is currently not finished.
1418
errno issues fixed by Andrew Bachmann.
1419

    
1420
Old stuff:
1421

    
1422
Fran├žois Revol - revol at free dot fr - April 2002
1423

    
1424
The configure script should guess the configuration itself,
1425
however I still did not test building on the net_server version of BeOS.
1426

    
1427
FFserver is broken (needs poll() implementation).
1428

    
1429
There are still issues with errno codes, which are negative in BeOS, and
1430
that FFmpeg negates when returning. This ends up turning errors into
1431
valid results, then crashes.
1432
(To be fixed)
1433

    
1434
@chapter Developers Guide
1435

    
1436
@section API
1437
@itemize @bullet
1438
@item libavcodec is the library containing the codecs (both encoding and
1439
decoding). Look at @file{libavcodec/apiexample.c} to see how to use it.
1440

    
1441
@item libavformat is the library containing the file format handling (mux and
1442
demux code for several formats). Look at @file{ffplay.c} to use it in a
1443
player. See @file{output_example.c} to use it to generate audio or video
1444
streams.
1445

    
1446
@end itemize
1447

    
1448
@section Integrating libavcodec or libavformat in your program
1449

    
1450
You can integrate all the source code of the libraries to link them
1451
statically to avoid any version problem. All you need is to provide a
1452
'config.mak' and a 'config.h' in the parent directory. See the defines
1453
generated by ./configure to understand what is needed.
1454

    
1455
You can use libavcodec or libavformat in your commercial program, but
1456
@emph{any patch you make must be published}. The best way to proceed is
1457
to send your patches to the FFmpeg mailing list.
1458

    
1459
@node Coding Rules
1460
@section Coding Rules
1461

    
1462
FFmpeg is programmed in the ISO C90 language with a few additional
1463
features from ISO C99, namely:
1464
@itemize @bullet
1465
@item
1466
the @samp{inline} keyword;
1467
@item
1468
@samp{//} comments;
1469
@item
1470
designated struct initializers (@samp{struct s x = @{ .i = 17 @};})
1471
@item
1472
compound literals (@samp{x = (struct s) @{ 17, 23 @};})
1473
@end itemize
1474

    
1475
These features are supported by all compilers we care about, so we will not
1476
accept patches to remove their use unless they absolutely do not impair
1477
clarity and performance.
1478

    
1479
All code must compile with GCC 2.95 and GCC 3.3. Currently, FFmpeg also
1480
compiles with several other compilers, such as the Compaq ccc compiler
1481
or Sun Studio 9, and we would like to keep it that way unless it would
1482
be exceedingly involved. To ensure compatibility, please do not use any
1483
additional C99 features or GCC extensions. Especially watch out for:
1484
@itemize @bullet
1485
@item
1486
mixing statements and declarations;
1487
@item
1488
@samp{long long} (use @samp{int64_t} instead);
1489
@item
1490
@samp{__attribute__} not protected by @samp{#ifdef __GNUC__} or similar;
1491
@item
1492
GCC statement expressions (@samp{(x = (@{ int y = 4; y; @})}).
1493
@end itemize
1494

    
1495
Indent size is 4.
1496
The presentation is the one specified by 'indent -i4 -kr -nut'.
1497
The TAB character is forbidden outside of Makefiles as is any
1498
form of trailing whitespace. Commits containing either will be
1499
rejected by the Subversion repository.
1500

    
1501
Main priority in FFmpeg is simplicity and small code size (=less
1502
bugs).
1503

    
1504
Comments: Use the JavaDoc/Doxygen
1505
format (see examples below) so that code documentation
1506
can be generated automatically. All nontrivial functions should have a comment
1507
above them explaining what the function does, even if it is just one sentence.
1508
All structures and their member variables should be documented, too.
1509
@example
1510
/**
1511
 * @@file mpeg.c
1512
 * MPEG codec.
1513
 * @@author ...
1514
 */
1515

    
1516
/**
1517
 * Summary sentence.
1518
 * more text ...
1519
 * ...
1520
 */
1521
typedef struct Foobar@{
1522
    int var1; /**< var1 description */
1523
    int var2; ///< var2 description
1524
    /** var3 description */
1525
    int var3;
1526
@} Foobar;
1527

    
1528
/**
1529
 * Summary sentence.
1530
 * more text ...
1531
 * ...
1532
 * @@param my_parameter description of my_parameter
1533
 * @@return return value description
1534
 */
1535
int myfunc(int my_parameter)
1536
...
1537
@end example
1538

    
1539
fprintf and printf are forbidden in libavformat and libavcodec,
1540
please use av_log() instead.
1541

    
1542
Casts should be used only when necessary. Unneeded parentheses
1543
should also be avoided if they don't make the code easier to understand.
1544

    
1545
@section Development Policy
1546

    
1547
@enumerate
1548
@item
1549
   You must not commit code which breaks FFmpeg! (Meaning unfinished but
1550
   enabled code which breaks compilation or compiles but does not work or
1551
   breaks the regression tests)
1552
   You can commit unfinished stuff (for testing etc), but it must be disabled
1553
   (#ifdef etc) by default so it does not interfere with other developers'
1554
   work.
1555
@item
1556
   You do not have to over-test things. If it works for you, and you think it
1557
   should work for others, then commit. If your code has problems
1558
   (portability, triggers compiler bugs, unusual environment etc) they will be
1559
   reported and eventually fixed.
1560
@item
1561
   Do not commit unrelated changes together, split them into self-contained
1562
   pieces. Also do not forget that if part B depends on part A, but A does not
1563
   depend on B, then A can and should be committed first and separate from B.
1564
   Keeping changes well split into self-contained parts makes reviewing and
1565
   understanding them on the commit log mailing list easier. This also helps
1566
   in case of debugging later on.
1567
   Also if you have doubts about splitting or not splitting, do not hesitate to
1568
   ask/discuss it on the developer mailing list.
1569
@item
1570
   Do not change behavior of the program (renaming options etc) without
1571
   first discussing it on the ffmpeg-devel mailing list. Do not remove
1572
   functionality from the code. Just improve!
1573

    
1574
   Note: Redundant code can be removed.
1575
@item
1576
   Do not commit changes to the build system (Makefiles, configure script)
1577
   which change behavior, defaults etc, without asking first. The same
1578
   applies to compiler warning fixes, trivial looking fixes and to code
1579
   maintained by other developers. We usually have a reason for doing things
1580
   the way we do. Send your changes as patches to the ffmpeg-devel mailing
1581
   list, and if the code maintainers say OK, you may commit. This does not
1582
   apply to files you wrote and/or maintain.
1583
@item
1584
   We refuse source indentation and other cosmetic changes if they are mixed
1585
   with functional changes, such commits will be rejected and removed. Every
1586
   developer has his own indentation style, you should not change it. Of course
1587
   if you (re)write something, you can use your own style, even though we would
1588
   prefer if the indentation throughout FFmpeg was consistent (Many projects
1589
   force a given indentation style - we do not.). If you really need to make
1590
   indentation changes (try to avoid this), separate them strictly from real
1591
   changes.
1592

    
1593
   NOTE: If you had to put if()@{ .. @} over a large (> 5 lines) chunk of code,
1594
   then either do NOT change the indentation of the inner part within (do not
1595
   move it to the right)! or do so in a separate commit
1596
@item
1597
   Always fill out the commit log message. Describe in a few lines what you
1598
   changed and why. You can refer to mailing list postings if you fix a
1599
   particular bug. Comments such as "fixed!" or "Changed it." are unacceptable.
1600
@item
1601
   If you apply a patch by someone else, include the name and email address in
1602
   the log message. Since the ffmpeg-cvslog mailing list is publicly
1603
   archived you should add some SPAM protection to the email address. Send an
1604
   answer to ffmpeg-devel (or wherever you got the patch from) saying that
1605
   you applied the patch.
1606
@item
1607
   When applying patches that have been discussed (at length) on the mailing
1608
   list, reference the thread in the log message.
1609
@item
1610
    Do NOT commit to code actively maintained by others without permission.
1611
    Send a patch to ffmpeg-devel instead. If no one answers within a reasonable
1612
    timeframe (12h for build failures and security fixes, 3 days small changes,
1613
    1 week for big patches) then commit your patch if you think it is OK.
1614
    Also note, the maintainer can simply ask for more time to review!
1615
@item
1616
    Subscribe to the ffmpeg-cvslog mailing list. The diffs of all commits
1617
    are sent there and reviewed by all the other developers. Bugs and possible
1618
    improvements or general questions regarding commits are discussed there. We
1619
    expect you to react if problems with your code are uncovered.
1620
@item
1621
    Update the documentation if you change behavior or add features. If you are
1622
    unsure how best to do this, send a patch to ffmpeg-devel, the documentation
1623
    maintainer(s) will review and commit your stuff.
1624
@item
1625
    Try to keep important discussions and requests (also) on the public
1626
    developer mailing list, so that all developers can benefit from them.
1627
@item
1628
    Never write to unallocated memory, never write over the end of arrays,
1629
    always check values read from some untrusted source before using them
1630
    as array index or other risky things.
1631
@item
1632
    Remember to check if you need to bump versions for the specific libav
1633
    parts (libavutil, libavcodec, libavformat) you are changing. You need
1634
    to change the version integer and the version string.
1635
    Incrementing the first component means no backward compatibility to
1636
    previous versions (e.g. removal of a function from the public API).
1637
    Incrementing the second component means backward compatible change
1638
    (e.g. addition of a function to the public API).
1639
    Incrementing the third component means a noteworthy binary compatible
1640
    change (e.g. encoder bug fix that matters for the decoder).
1641
@item
1642
    If you add a new codec, remember to update the changelog, add it to
1643
    the supported codecs table in the documentation and bump the second
1644
    component of the @file{libavcodec} version number appropriately. If
1645
    it has a fourcc, add it to @file{libavformat/avienc.c}, even if it
1646
    is only a decoder.
1647
@item
1648
    Do not change code to hide warnings without ensuring that the underlying
1649
    logic is correct and thus the warning was inappropriate.
1650
@item
1651
    If you add a new file, give it a proper license header. Do not copy and
1652
    paste it from a random place, use an existing file as template.
1653
@end enumerate
1654

    
1655
We think our rules are not too hard. If you have comments, contact us.
1656

    
1657
Note, these rules are mostly borrowed from the MPlayer project.
1658

    
1659
@section Submitting patches
1660

    
1661
First, (@pxref{Coding Rules}) above if you did not yet.
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1663
When you submit your patch, try to send a unified diff (diff '-up'
1664
option). I cannot read other diffs :-)
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1666
Also please do not submit patches which contain several unrelated changes.
1667
Split them into individual self-contained patches; this makes reviewing
1668
them much easier.
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1670
Run the regression tests before submitting a patch so that you can
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verify that there are no big problems.
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Patches should be posted as base64 encoded attachments (or any other
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encoding which ensures that the patch will not be trashed during
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transmission) to the ffmpeg-devel mailing list, see
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@url{http://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel}
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It also helps quite a bit if you tell us what the patch does (for example
1679
'replaces lrint by lrintf'), and why (for example '*BSD isn't C99 compliant
1680
and has no lrint()')
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Also please if you send several patches, send each patch as separate mail,
1683
do not attach several unrelated patches to the same mail.
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1685
@section patch submission checklist
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1687
@enumerate
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@item
1689
    Do the regression tests pass with the patch applied?
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@item
1691
    Is the patch a unified diff?
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@item
1693
    Is the patch against latest FFmpeg SVN?
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@item
1695
    Are you subscribed to ffmpeg-dev?
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    (the list is subscribers only due to spam)
1697
@item
1698
    Have you checked that the changes are minimal, so that the same cannot be
1699
    achieved with a smaller patch and/or simpler final code?
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@item
1701
    If the change is to speed critical code, did you benchmark it?
1702
@item
1703
    If you did any benchmarks, did you provide them in the mail?
1704
@item
1705
    Have you checked that the patch does not introduce buffer overflows or
1706
    other security issues?
1707
@item
1708
    Is the patch created from the root of the source tree, so it can be
1709
    applied with @code{patch -p0}?
1710
@item
1711
    Does the patch not mix functional and cosmetic changes?
1712
@item
1713
    Did you add tabs or trailing whitespace to the code? Both are forbidden.
1714
@item
1715
    Is the patch attached to the email you send?
1716
@item
1717
    Is the mime type of the patch correct? It should be text/x-diff or
1718
    text/x-patch or at least text/plain and not application/octet-stream.
1719
@item
1720
    If the patch fixes a bug, did you provide a verbose analysis of the bug?
1721
@item
1722
    If the patch fixes a bug, did you provide enough information, including
1723
    a sample, so the bug can be reproduced and the fix can be verified?
1724
    Note please do not attach samples >100k to mails but rather provide a
1725
    URL, you can upload to ftp://upload.mplayerhq.hu
1726
@item
1727
    Did you provide a verbose summary about what the patch does change?
1728
@item
1729
    Did you provide a verbose explanation why it changes things like it does?
1730
@item
1731
    Did you provide a verbose summary of the user visible advantages and
1732
    disadvantages if the patch is applied?
1733
@item
1734
    Did you provide an example so we can verify the new feature added by the
1735
    patch easily?
1736
@item
1737
    If you added a new file, did you insert a license header? It should be
1738
    taken from FFmpeg, not randomly copied and pasted from somewhere else.
1739
@item
1740
    You should maintain alphabetical order in alphabetically ordered lists as
1741
    long as doing so does not break API/ABI compatibility.
1742
@item
1743
    Did you provide a suggestion for a clear commit log message?
1744
@end enumerate
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1746
@section Patch review process
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1748
All patches posted to ffmpeg-devel will be reviewed, unless they contain a
1749
clear note that the patch is not for SVN.
1750
Reviews and comments will be posted as replies to the patch on the
1751
mailing list. The patch submitter then has to take care of every comment,
1752
that can be by resubmitting a changed patch or by discussion. Resubmitted
1753
patches will themselves be reviewed like any other patch. If at some point
1754
a patch passes review with no comments then it is approved, that can for
1755
simple and small patches happen immediately while large patches will generally
1756
have to be changed and reviewed many times before they are approved.
1757
After a patch is approved it will be committed to the repository.
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1759
We will review all submitted patches, but sometimes we are quite busy so
1760
especially for large patches this can take several weeks.
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1762
When resubmitting patches, please do not make any significant changes
1763
not related to the comments received during review. Such patches will
1764
be rejected. Instead, submit  significant changes or new features as
1765
separate patches.
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1767
@section Regression tests
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1769
Before submitting a patch (or committing to the repository), you should at least
1770
test that you did not break anything.
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1772
The regression tests build a synthetic video stream and a synthetic
1773
audio stream. These are then encoded and decoded with all codecs or
1774
formats. The CRC (or MD5) of each generated file is recorded in a
1775
result file. A 'diff' is launched to compare the reference results and
1776
the result file.
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1778
The regression tests then go on to test the FFserver code with a
1779
limited set of streams. It is important that this step runs correctly
1780
as well.
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1782
Run 'make test' to test all the codecs and formats.
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1784
Run 'make fulltest' to test all the codecs, formats and FFserver.
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1786
[Of course, some patches may change the results of the regression tests. In
1787
this case, the reference results of the regression tests shall be modified
1788
accordingly].
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@bye