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\input texinfo @c -*- texinfo -*-
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@settitle FFmpeg Documentation
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@titlepage
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@sp 7
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@center @titlefont{FFmpeg Documentation}
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@sp 3
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@end titlepage
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@chapter Introduction
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FFmpeg is a very fast video and audio converter. It can also grab from
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a live audio/video source.
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The command line interface is designed to be intuitive, in the sense
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that FFmpeg tries to figure out all parameters that can possibly be
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derived automatically. You usually only have to specify the target
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bitrate you want.
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FFmpeg can also convert from any sample rate to any other, and resize
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video on the fly with a high quality polyphase filter.
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@chapter Quick Start
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@c man begin EXAMPLES
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@section Video and Audio grabbing
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FFmpeg can use a video4linux compatible video source and any Open Sound
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System audio source:
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@example
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ffmpeg /tmp/out.mpg
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@end example
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Note that you must activate the right video source and channel before
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launching FFmpeg with any TV viewer such as xawtv
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(@url{http://bytesex.org/xawtv/}) by Gerd Knorr. You also
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have to set the audio recording levels correctly with a
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standard mixer.
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@section X11 grabbing
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FFmpeg can grab the X11 display.
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@example
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ffmpeg -f x11grab -vd x11:0.0 /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 -vd x11:0.0+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 64 /tmp/a.mp2 -ab 128 /tmp/b.mp2 -map 0:0 -map 0:0
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@end example
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Converts a.wav to a.mp2 at 64 kbits and to b.mp2 at 128 kbits. '-map
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file:index' specifies which input stream is used for each output
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stream, in the order of the definition of output streams.
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* You can transcode decrypted VOBs
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@example
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ffmpeg -i snatch_1.vob -f avi -vcodec mpeg4 -b 800k -g 300 -bf 2 -acodec mp3 -ab 128 snatch.avi
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@end example
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This is a typical DVD ripping example; the input is a VOB file, the
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output an AVI file with MPEG-4 video and MP3 audio. Note that in this
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command we use B-frames so the MPEG-4 stream is DivX5 compatible, and
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GOP size is 300 which means one intra frame every 10 seconds for 29.97fps
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input video. Furthermore, the audio stream is MP3-encoded so you need
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to enable LAME support by passing @code{--enable-mp3lame} to configure.
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The mapping is particularly useful for DVD transcoding
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to get the desired audio language.
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NOTE: To see the supported input formats, use @code{ffmpeg -formats}.
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@c man end
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@chapter Invocation
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@section Syntax
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The generic syntax is:
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@example
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@c man begin SYNOPSIS
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ffmpeg [[infile options][@option{-i} @var{infile}]]... @{[outfile options] @var{outfile}@}...
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@c man end
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@end example
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@c man begin DESCRIPTION
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If no input file is given, audio/video grabbing is done.
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As a general rule, options are applied to the next specified
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file. 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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@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.
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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 -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 kbit/s (default = 64).
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@item -ac channels
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Set the number of audio channels (default = 1).
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@item -an
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Disable audio recording.
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@item -acodec codec
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Force audio codec to @var{codec}. Use the @code{copy} special value to
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specify that the raw codec data must be copied as is.
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@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 384 test.mpg -acodec mp2 -ab 192 -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 -vd device
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sEt video grab device (e.g. @file{/dev/video0}).
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@item -vc channel
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Set video grab channel (DV1394 only).
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@item -tvstd standard
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Set television standard (NTSC, PAL (SECAM)).
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@item -dv1394
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Set DV1394 grab.
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@item -ad device
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Set audio device (e.g. @file{/dev/dsp}).
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@item -grab format
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Request grabbing using.
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@item -gd device
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Set grab device.
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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.
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Just enumerate the input streams in the order you want them in the output.
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[input stream id] sets the (input) stream to sync against.
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@item -map_meta_data outfile:infile
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Set meta data information of outfile from infile.
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@item -debug
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Print specific debug info.
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@item -benchmark
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Add timings for benchmarking.
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@item -dump
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Dump each input packet.
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@item -hex
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When dumping packets, also dump the payload.
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@item -bitexact
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Only use bit exact algorithms (for codec testing).
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@item -ps size
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Set packet size in bits.
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@item -re
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Read input at native frame rate. Mainly used to simulate a grab device.
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@item -loop_input
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Loop over the input stream. Currently it works only for image
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streams. This option is used for automatic FFserver testing.
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@item -loop_output number_of_times
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Repeatedly loop output for formats that support looping such as animated GIF
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(0 will loop the output infinitely).
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@item -threads count
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Thread count.
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@item -vsync parameter
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Video sync method. Video will be stretched/squeezed to match the timestamps,
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it is done by duplicating and dropping frames. With -map you can select from
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which stream the timestamps should be taken. You can leave either video or
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audio unchanged and sync the remaining stream(s) to the unchanged one.
664
@item -async samples_per_second
665
Audio sync method. "Stretches/squeezes" the audio stream to match the timestamps,
666
the parameter is the maximum samples per second by which the audio is changed.
667
-async 1 is a special case where only the start of the audio stream is corrected
668
without any later correction.
669
@end table
670

    
671
@node FFmpeg formula evaluator
672
@section FFmpeg formula evaluator
673

    
674
When evaluating a rate control string, FFmpeg uses an internal formula
675
evaluator.
676

    
677
The following binary operators are available: @code{+}, @code{-},
678
@code{*}, @code{/}, @code{^}.
679

    
680
The following unary operators are available: @code{+}, @code{-},
681
@code{(...)}.
682

    
683
The following functions are available:
684
@table @var
685
@item sinh(x)
686
@item cosh(x)
687
@item tanh(x)
688
@item sin(x)
689
@item cos(x)
690
@item tan(x)
691
@item exp(x)
692
@item log(x)
693
@item squish(x)
694
@item gauss(x)
695
@item abs(x)
696
@item max(x, y)
697
@item min(x, y)
698
@item gt(x, y)
699
@item lt(x, y)
700
@item eq(x, y)
701
@item bits2qp(bits)
702
@item qp2bits(qp)
703
@end table
704

    
705
The following constants are available:
706
@table @var
707
@item PI
708
@item E
709
@item iTex
710
@item pTex
711
@item tex
712
@item mv
713
@item fCode
714
@item iCount
715
@item mcVar
716
@item var
717
@item isI
718
@item isP
719
@item isB
720
@item avgQP
721
@item qComp
722
@item avgIITex
723
@item avgPITex
724
@item avgPPTex
725
@item avgBPTex
726
@item avgTex
727
@end table
728

    
729
@c man end
730

    
731
@ignore
732

    
733
@setfilename ffmpeg
734
@settitle FFmpeg video converter
735

    
736
@c man begin SEEALSO
737
ffserver(1), ffplay(1) and the HTML documentation of @file{ffmpeg}.
738
@c man end
739

    
740
@c man begin AUTHOR
741
Fabrice Bellard
742
@c man end
743

    
744
@end ignore
745

    
746
@section Protocols
747

    
748
The filename can be @file{-} to read from standard input or to write
749
to standard output.
750

    
751
FFmpeg also handles many protocols specified with an URL syntax.
752

    
753
Use 'ffmpeg -formats' to see a list of the supported protocols.
754

    
755
The protocol @code{http:} is currently used only to communicate with
756
FFserver (see the FFserver documentation). When FFmpeg will be a
757
video player it will also be used for streaming :-)
758

    
759
@chapter Tips
760

    
761
@itemize
762
@item For streaming at very low bitrate application, use a low frame rate
763
and a small GOP size. This is especially true for RealVideo where
764
the Linux player does not seem to be very fast, so it can miss
765
frames. An example is:
766

    
767
@example
768
ffmpeg -g 3 -r 3 -t 10 -b 50k -s qcif -f rv10 /tmp/b.rm
769
@end example
770

    
771
@item  The parameter 'q' which is displayed while encoding is the current
772
quantizer. The value 1 indicates that a very good quality could
773
be achieved. The value 31 indicates the worst quality. If q=31 appears
774
too often, it means that the encoder cannot compress enough to meet
775
your bitrate. You must either increase the bitrate, decrease the
776
frame rate or decrease the frame size.
777

    
778
@item If your computer is not fast enough, you can speed up the
779
compression at the expense of the compression ratio. You can use
780
'-me zero' to speed up motion estimation, and '-intra' to disable
781
motion estimation completely (you have only I-frames, which means it
782
is about as good as JPEG compression).
783

    
784
@item To have very low audio bitrates, reduce the sampling frequency
785
(down to 22050 kHz for MPEG audio, 22050 or 11025 for AC3).
786

    
787
@item To have a constant quality (but a variable bitrate), use the option
788
'-qscale n' when 'n' is between 1 (excellent quality) and 31 (worst
789
quality).
790

    
791
@item When converting video files, you can use the '-sameq' option which
792
uses the same quality factor in the encoder as in the decoder.
793
It allows almost lossless encoding.
794

    
795
@end itemize
796

    
797

    
798
@chapter external libraries
799

    
800
FFmpeg can be hooked up with a number of external libraries to add support
801
for more formats.
802

    
803
@section AMR
804

    
805
AMR comes in two different flavors, WB and NB. FFmpeg can make use of the
806
AMR WB (floating-point mode) and the AMR NB (both floating-point and
807
fixed-point mode) reference decoders and encoders.
808

    
809
@itemize
810

    
811
@item For AMR WB floating-point download TS26.204 V5.1.0 from
812
@url{http://www.3gpp.org/ftp/Specs/archive/26_series/26.204/26204-510.zip}
813
and extract the source to @file{libavcodec/amrwb_float/}.
814

    
815
@item For AMR NB floating-point download TS26.104 REL-5 V5.1.0 from
816
@url{http://www.3gpp.org/ftp/Specs/archive/26_series/26.104/26104-510.zip}
817
and extract the source to @file{libavcodec/amr_float/}.
818
If you try this on Alpha, you may need to change @code{Word32} to
819
@code{int} in @file{amr/typedef.h}.
820

    
821
@item For AMR NB fixed-point download TS26.073 REL-5 V5.1.0 from
822
@url{http://www.3gpp.org/ftp/Specs/archive/26_series/26.073/26073-510.zip}
823
and extract the source to @file{libavcodec/amr}.
824
You must also add @code{-DMMS_IO} and remove @code{-pedantic-errors}
825
to/from @code{CFLAGS} in @file{libavcodec/amr/makefile}, i.e.
826
``@code{CFLAGS = -Wall -I. \$(CFLAGS_\$(MODE)) -D\$(VAD) -DMMS_IO}''.
827

    
828
@end itemize
829

    
830

    
831
@chapter Supported File Formats and Codecs
832

    
833
You can use the @code{-formats} option to have an exhaustive list.
834

    
835
@section File Formats
836

    
837
FFmpeg supports the following file formats through the @code{libavformat}
838
library:
839

    
840
@multitable @columnfractions .4 .1 .1 .4
841
@item Supported File Format @tab Encoding @tab Decoding @tab Comments
842
@item MPEG audio @tab X @tab X
843
@item MPEG-1 systems @tab X  @tab  X
844
@tab muxed audio and video
845
@item MPEG-2 PS @tab X  @tab  X
846
@tab also known as @code{VOB} file
847
@item MPEG-2 TS @tab    @tab  X
848
@tab also known as DVB Transport Stream
849
@item ASF@tab X @tab X
850
@item AVI@tab X @tab X
851
@item WAV@tab X @tab X
852
@item Macromedia Flash@tab X @tab X
853
@tab Only embedded audio is decoded.
854
@item FLV              @tab  X @tab X
855
@tab Macromedia Flash video files
856
@item Real Audio and Video @tab X @tab X
857
@item Raw AC3 @tab X  @tab  X
858
@item Raw MJPEG @tab X  @tab  X
859
@item Raw MPEG video @tab X  @tab  X
860
@item Raw PCM8/16 bits, mulaw/Alaw@tab X  @tab  X
861
@item Raw CRI ADX audio @tab X  @tab  X
862
@item Raw Shorten audio @tab    @tab  X
863
@item SUN AU format @tab X  @tab  X
864
@item NUT @tab X @tab X @tab NUT Open Container Format
865
@item QuickTime        @tab X @tab  X
866
@item MPEG-4           @tab X @tab  X
867
@tab MPEG-4 is a variant of QuickTime.
868
@item Raw MPEG4 video  @tab  X @tab  X
869
@item DV               @tab  X @tab  X
870
@item 4xm              @tab    @tab X
871
@tab 4X Technologies format, used in some games.
872
@item Playstation STR  @tab    @tab X
873
@item Id RoQ           @tab    @tab X
874
@tab Used in Quake III, Jedi Knight 2, other computer games.
875
@item Interplay MVE    @tab    @tab X
876
@tab Format used in various Interplay computer games.
877
@item WC3 Movie        @tab    @tab X
878
@tab Multimedia format used in Origin's Wing Commander III computer game.
879
@item Sega FILM/CPK    @tab    @tab X
880
@tab Used in many Sega Saturn console games.
881
@item Westwood Studios VQA/AUD  @tab    @tab X
882
@tab Multimedia formats used in Westwood Studios games.
883
@item Id Cinematic (.cin) @tab    @tab X
884
@tab Used in Quake II.
885
@item FLIC format      @tab    @tab X
886
@tab .fli/.flc files
887
@item Sierra VMD       @tab    @tab X
888
@tab Used in Sierra CD-ROM games.
889
@item Sierra Online    @tab    @tab X
890
@tab .sol files used in Sierra Online games.
891
@item Matroska         @tab    @tab X
892
@item Electronic Arts Multimedia    @tab    @tab X
893
@tab Used in various EA games; files have extensions like WVE and UV2.
894
@item Nullsoft Video (NSV) format @tab    @tab X
895
@item ADTS AAC audio @tab X @tab X
896
@item Creative VOC @tab X @tab X @tab Created for the Sound Blaster Pro.
897
@item American Laser Games MM  @tab    @tab X
898
@tab Multimedia format used in games like Mad Dog McCree
899
@item AVS @tab    @tab X
900
@tab Multimedia format used by the Creature Shock game.
901
@item Smacker @tab    @tab X
902
@tab Multimedia format used by many games.
903
@item GXF @tab  X @tab X
904
@tab General eXchange Format SMPTE 360M, used by Thomson Grass Valley playout servers.
905
@item CIN @tab    @tab X
906
@tab Multimedia format used by Delphine Software games.
907
@item MXF @tab    @tab X
908
@tab Material eXchange Format SMPTE 377M, used by D-Cinema, broadcast industry.
909
@item SEQ @tab    @tab X
910
@tab Tiertex .seq files used in the DOS CDROM version of the game Flashback.
911
@end multitable
912

    
913
@code{X} means that encoding (resp. decoding) is supported.
914

    
915
@section Image Formats
916

    
917
FFmpeg can read and write images for each frame of a video sequence. The
918
following image formats are supported:
919

    
920
@multitable @columnfractions .4 .1 .1 .4
921
@item Supported Image Format @tab Encoding @tab Decoding @tab Comments
922
@item PGM, PPM     @tab X @tab X
923
@item PAM          @tab X @tab X @tab PAM is a PNM extension with alpha support.
924
@item PGMYUV       @tab X @tab X @tab PGM with U and V components in YUV 4:2:0
925
@item JPEG         @tab X @tab X @tab Progressive JPEG is not supported.
926
@item .Y.U.V       @tab X @tab X @tab one raw file per component
927
@item animated GIF @tab X @tab X @tab Only uncompressed GIFs are generated.
928
@item PNG          @tab X @tab X @tab 2 bit and 4 bit/pixel not supported yet.
929
@item Targa        @tab   @tab X @tab Targa (.TGA) image format.
930
@item TIFF         @tab   @tab X @tab Only 24 bit/pixel images are supported.
931
@item SGI          @tab X @tab X @tab SGI RGB image format
932
@end multitable
933

    
934
@code{X} means that encoding (resp. decoding) is supported.
935

    
936
@section Video Codecs
937

    
938
@multitable @columnfractions .4 .1 .1 .4
939
@item Supported Codec @tab Encoding @tab Decoding @tab Comments
940
@item MPEG-1 video           @tab  X  @tab  X
941
@item MPEG-2 video           @tab  X  @tab  X
942
@item MPEG-4                 @tab  X  @tab  X
943
@item MSMPEG4 V1             @tab  X  @tab  X
944
@item MSMPEG4 V2             @tab  X  @tab  X
945
@item MSMPEG4 V3             @tab  X  @tab  X
946
@item WMV7                   @tab  X  @tab  X
947
@item WMV8                   @tab  X  @tab  X @tab not completely working
948
@item WMV9                   @tab     @tab  X @tab not completely working
949
@item VC1                    @tab     @tab  X
950
@item H.261                  @tab  X  @tab  X
951
@item H.263(+)               @tab  X  @tab  X @tab also known as RealVideo 1.0
952
@item H.264                  @tab     @tab  X
953
@item RealVideo 1.0          @tab  X  @tab  X
954
@item RealVideo 2.0          @tab  X  @tab  X
955
@item MJPEG                  @tab  X  @tab  X
956
@item lossless MJPEG         @tab  X  @tab  X
957
@item JPEG-LS                @tab  X  @tab  X @tab fourcc: MJLS, lossless and near-lossless is supported
958
@item Apple MJPEG-B          @tab     @tab  X
959
@item Sunplus MJPEG          @tab     @tab  X @tab fourcc: SP5X
960
@item DV                     @tab  X  @tab  X
961
@item HuffYUV                @tab  X  @tab  X
962
@item FFmpeg Video 1         @tab  X  @tab  X @tab experimental lossless codec (fourcc: FFV1)
963
@item FFmpeg Snow            @tab  X  @tab  X @tab experimental wavelet codec (fourcc: SNOW)
964
@item Asus v1                @tab  X  @tab  X @tab fourcc: ASV1
965
@item Asus v2                @tab  X  @tab  X @tab fourcc: ASV2
966
@item Creative YUV           @tab     @tab  X @tab fourcc: CYUV
967
@item Sorenson Video 1       @tab  X  @tab  X @tab fourcc: SVQ1
968
@item Sorenson Video 3       @tab     @tab  X @tab fourcc: SVQ3
969
@item On2 VP3                @tab     @tab  X @tab still experimental
970
@item On2 VP5                @tab     @tab  X @tab fourcc: VP50
971
@item On2 VP6                @tab     @tab  X @tab fourcc: VP60,VP61,VP62
972
@item Theora                 @tab  X  @tab  X @tab still experimental
973
@item Intel Indeo 3          @tab     @tab  X
974
@item FLV                    @tab  X  @tab  X @tab Sorenson H.263 used in Flash
975
@item Flash Screen Video     @tab  X  @tab  X @tab fourcc: FSV1
976
@item ATI VCR1               @tab     @tab  X @tab fourcc: VCR1
977
@item ATI VCR2               @tab     @tab  X @tab fourcc: VCR2
978
@item Cirrus Logic AccuPak   @tab     @tab  X @tab fourcc: CLJR
979
@item 4X Video               @tab     @tab  X @tab Used in certain computer games.
980
@item Sony Playstation MDEC  @tab     @tab  X
981
@item Id RoQ                 @tab     @tab  X @tab Used in Quake III, Jedi Knight 2, other computer games.
982
@item Xan/WC3                @tab     @tab  X @tab Used in Wing Commander III .MVE files.
983
@item Interplay Video        @tab     @tab  X @tab Used in Interplay .MVE files.
984
@item Apple Animation        @tab     @tab  X @tab fourcc: 'rle '
985
@item Apple Graphics         @tab     @tab  X @tab fourcc: 'smc '
986
@item Apple Video            @tab     @tab  X @tab fourcc: rpza
987
@item Apple QuickDraw        @tab     @tab  X @tab fourcc: qdrw
988
@item Cinepak                @tab     @tab  X
989
@item Microsoft RLE          @tab     @tab  X
990
@item Microsoft Video-1      @tab     @tab  X
991
@item Westwood VQA           @tab     @tab  X
992
@item Id Cinematic Video     @tab     @tab  X @tab Used in Quake II.
993
@item Planar RGB             @tab     @tab  X @tab fourcc: 8BPS
994
@item FLIC video             @tab     @tab  X
995
@item Duck TrueMotion v1     @tab     @tab  X @tab fourcc: DUCK
996
@item Duck TrueMotion v2     @tab     @tab  X @tab fourcc: TM20
997
@item VMD Video              @tab     @tab  X @tab Used in Sierra VMD files.
998
@item MSZH                   @tab     @tab  X @tab Part of LCL
999
@item ZLIB                   @tab  X  @tab  X @tab Part of LCL, encoder experimental
1000
@item TechSmith Camtasia     @tab     @tab  X @tab fourcc: TSCC
1001
@item IBM Ultimotion         @tab     @tab  X @tab fourcc: ULTI
1002
@item Miro VideoXL           @tab     @tab  X @tab fourcc: VIXL
1003
@item QPEG                   @tab     @tab  X @tab fourccs: QPEG, Q1.0, Q1.1
1004
@item LOCO                   @tab     @tab  X @tab
1005
@item Winnov WNV1            @tab     @tab  X @tab
1006
@item Autodesk Animator Studio Codec  @tab     @tab  X @tab fourcc: AASC
1007
@item Fraps FPS1             @tab     @tab  X @tab
1008
@item CamStudio              @tab     @tab  X @tab fourcc: CSCD
1009
@item American Laser Games Video  @tab    @tab X @tab Used in games like Mad Dog McCree
1010
@item ZMBV                   @tab   X @tab  X @tab Encoder works only on PAL8
1011
@item AVS Video              @tab     @tab  X @tab Video encoding used by the Creature Shock game.
1012
@item Smacker Video          @tab     @tab  X @tab Video encoding used in Smacker.
1013
@item RTjpeg                 @tab     @tab  X @tab Video encoding used in NuppelVideo files.
1014
@item KMVC                   @tab     @tab  X @tab Codec used in Worms games.
1015
@item VMware Video           @tab     @tab  X @tab Codec used in videos captured by VMware.
1016
@item Cin Video              @tab     @tab  X @tab Codec used in Delphine Software games.
1017
@item Tiertex Seq Video      @tab     @tab  X @tab Codec used in DOS CDROM FlashBack game.
1018
@end multitable
1019

    
1020
@code{X} means that encoding (resp. decoding) is supported.
1021

    
1022
@section Audio Codecs
1023

    
1024
@multitable @columnfractions .4 .1 .1 .1 .7
1025
@item Supported Codec @tab Encoding @tab Decoding @tab Comments
1026
@item MPEG audio layer 2     @tab  IX  @tab  IX
1027
@item MPEG audio layer 1/3   @tab IX   @tab  IX
1028
@tab MP3 encoding is supported through the external library LAME.
1029
@item AC3                    @tab  IX  @tab  IX
1030
@tab liba52 is used internally for decoding.
1031
@item Vorbis                 @tab  X   @tab  X
1032
@item WMA V1/V2              @tab X    @tab X
1033
@item AAC                    @tab X    @tab X
1034
@tab Supported through the external library libfaac/libfaad.
1035
@item Microsoft ADPCM        @tab X    @tab X
1036
@item MS IMA ADPCM           @tab X    @tab X
1037
@item QT IMA ADPCM           @tab      @tab X
1038
@item 4X IMA ADPCM           @tab      @tab X
1039
@item G.726  ADPCM           @tab X    @tab X
1040
@item Duck DK3 IMA ADPCM     @tab      @tab X
1041
@tab Used in some Sega Saturn console games.
1042
@item Duck DK4 IMA ADPCM     @tab      @tab X
1043
@tab Used in some Sega Saturn console games.
1044
@item Westwood Studios IMA ADPCM @tab      @tab X
1045
@tab Used in Westwood Studios games like Command and Conquer.
1046
@item SMJPEG IMA ADPCM       @tab      @tab X
1047
@tab Used in certain Loki game ports.
1048
@item CD-ROM XA ADPCM        @tab      @tab X
1049
@item CRI ADX ADPCM          @tab X    @tab X
1050
@tab Used in Sega Dreamcast games.
1051
@item Electronic Arts ADPCM  @tab      @tab X
1052
@tab Used in various EA titles.
1053
@item Creative ADPCM         @tab      @tab X
1054
@tab 16 -> 4, 8 -> 4, 8 -> 3, 8 -> 2
1055
@item RA144                  @tab      @tab X
1056
@tab Real 14400 bit/s codec
1057
@item RA288                  @tab      @tab X
1058
@tab Real 28800 bit/s codec
1059
@item RADnet                 @tab X    @tab IX
1060
@tab Real low bitrate AC3 codec, liba52 is used for decoding.
1061
@item AMR-NB                 @tab X    @tab X
1062
@tab Supported through an external library.
1063
@item AMR-WB                 @tab X    @tab X
1064
@tab Supported through an external library.
1065
@item DV audio               @tab      @tab X
1066
@item Id RoQ DPCM            @tab      @tab X
1067
@tab Used in Quake III, Jedi Knight 2, other computer games.
1068
@item Interplay MVE DPCM     @tab      @tab X
1069
@tab Used in various Interplay computer games.
1070
@item Xan DPCM               @tab      @tab X
1071
@tab Used in Origin's Wing Commander IV AVI files.
1072
@item Sierra Online DPCM     @tab      @tab X
1073
@tab Used in Sierra Online game audio files.
1074
@item Apple MACE 3           @tab      @tab X
1075
@item Apple MACE 6           @tab      @tab X
1076
@item FLAC lossless audio    @tab      @tab X
1077
@item Shorten lossless audio @tab      @tab X
1078
@item Apple lossless audio   @tab      @tab X
1079
@tab QuickTime fourcc 'alac'
1080
@item FFmpeg Sonic           @tab X    @tab X
1081
@tab experimental lossy/lossless codec
1082
@item Qdesign QDM2           @tab      @tab X
1083
@tab there are still some distortions
1084
@item Real COOK              @tab      @tab X
1085
@tab All versions except 5.1 are supported
1086
@item DSP Group TrueSpeech   @tab      @tab X
1087
@item True Audio (TTA)       @tab      @tab X
1088
@item Smacker Audio          @tab      @tab X
1089
@item WavPack Audio          @tab      @tab X
1090
@item Cin Audio              @tab      @tab X
1091
@tab Codec used in Delphine Software games.
1092
@item Intel Music Coder      @tab      @tab X
1093
@item Musepack               @tab      @tab X
1094
@tab Only SV7 is supported
1095
@end multitable
1096

    
1097
@code{X} means that encoding (resp. decoding) is supported.
1098

    
1099
@code{I} means that an integer-only version is available, too (ensures high
1100
performance on systems without hardware floating point support).
1101

    
1102
@chapter Platform Specific information
1103

    
1104
@section BSD
1105

    
1106
BSD make will not build FFmpeg, you need to install and use GNU Make
1107
(@file{gmake}).
1108

    
1109
@section Windows
1110

    
1111
To get help and instructions for using FFmpeg under Windows, check out
1112
the FFmpeg Windows Help Forum at
1113
@url{http://arrozcru.no-ip.org/ffmpeg/}.
1114

    
1115
@subsection Native Windows compilation
1116

    
1117
@itemize
1118
@item Install the current versions of MSYS and MinGW from
1119
@url{http://www.mingw.org/}. You can find detailed installation
1120
instructions in the download section and the FAQ.
1121

    
1122
@item If you want to test the FFplay, also download
1123
the MinGW development library of SDL 1.2.x
1124
(@file{SDL-devel-1.2.x-mingw32.tar.gz}) from
1125
@url{http://www.libsdl.org}. Unpack it in a temporary directory, and
1126
unpack the archive @file{i386-mingw32msvc.tar.gz} in the MinGW tool
1127
directory. Edit the @file{sdl-config} script so that it gives the
1128
correct SDL directory when invoked.
1129

    
1130
@item Extract the current version of FFmpeg.
1131

    
1132
@item Start the MSYS shell (file @file{msys.bat}).
1133

    
1134
@item Change to the FFmpeg directory and follow
1135
 the instructions of how to compile FFmpeg (file
1136
@file{INSTALL}). Usually, launching @file{./configure} and @file{make}
1137
suffices. If you have problems using SDL, verify that
1138
@file{sdl-config} can be launched from the MSYS command line.
1139

    
1140
@item You can install FFmpeg in @file{Program Files/FFmpeg} by typing
1141
@file{make install}. Don't forget to copy @file{SDL.dll} to the place
1142
you launch @file{ffplay} from.
1143

    
1144
@end itemize
1145

    
1146
Notes:
1147
@itemize
1148

    
1149
@item The target @file{make wininstaller} can be used to create a
1150
Nullsoft based Windows installer for FFmpeg and FFplay. @file{SDL.dll}
1151
must be copied to the FFmpeg directory in order to build the
1152
installer.
1153

    
1154
@item By using @code{./configure --enable-shared} when configuring FFmpeg,
1155
you can build @file{avcodec.dll} and @file{avformat.dll}. With
1156
@code{make install} you install the FFmpeg DLLs and the associated
1157
headers in @file{Program Files/FFmpeg}.
1158

    
1159
@item Visual C++ compatibility: If you used @code{./configure --enable-shared}
1160
when configuring FFmpeg, FFmpeg tries to use the Microsoft Visual
1161
C++ @code{lib} tool to build @code{avcodec.lib} and
1162
@code{avformat.lib}. With these libraries you can link your Visual C++
1163
code directly with the FFmpeg DLLs (see below).
1164

    
1165
@end itemize
1166

    
1167
@subsection Visual C++ compatibility
1168

    
1169
FFmpeg will not compile under Visual C++ -- and it has too many
1170
dependencies on the GCC compiler to make a port viable. However,
1171
if you want to use the FFmpeg libraries in your own applications,
1172
you can still compile those applications using Visual C++. An
1173
important restriction to this is that you have to use the
1174
dynamically linked versions of the FFmpeg libraries (i.e. the
1175
DLLs), and you have to make sure that Visual-C++-compatible
1176
import libraries are created during the FFmpeg build process.
1177

    
1178
This description of how to use the FFmpeg libraries with Visual C++ is
1179
based on Visual C++ 2005 Express Edition Beta 2. If you have a different
1180
version, you might have to modify the procedures slightly.
1181

    
1182
Here are the step-by-step instructions for building the FFmpeg libraries
1183
so they can be used with Visual C++:
1184

    
1185
@enumerate
1186

    
1187
@item Install Visual C++ (if you haven't done so already).
1188

    
1189
@item Install MinGW and MSYS as described above.
1190

    
1191
@item Add a call to @file{vcvars32.bat} (which sets up the environment
1192
variables for the Visual C++ tools) as the first line of
1193
@file{msys.bat}. The standard location for @file{vcvars32.bat} is
1194
@file{C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat},
1195
and the standard location for @file{msys.bat} is
1196
@file{C:\msys\1.0\msys.bat}. If this corresponds to your setup, add the
1197
following line as the first line of @file{msys.bat}:
1198

    
1199
@code{call "C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat"}
1200

    
1201
@item Start the MSYS shell (file @file{msys.bat}) and type @code{link.exe}.
1202
If you get a help message with the command line options of @code{link.exe},
1203
this means your environment variables are set up correctly, the
1204
Microsoft linker is on the path and will be used by FFmpeg to
1205
create Visual-C++-compatible import libraries.
1206

    
1207
@item Extract the current version of FFmpeg and change to the FFmpeg directory.
1208

    
1209
@item Type the command
1210
@code{./configure --enable-shared --disable-static --enable-memalign-hack}
1211
to configure and, if that didn't produce any errors,
1212
type @code{make} to build FFmpeg.
1213

    
1214
@item The subdirectories @file{libavformat}, @file{libavcodec}, and
1215
@file{libavutil} should now contain the files @file{avformat.dll},
1216
@file{avformat.lib}, @file{avcodec.dll}, @file{avcodec.lib},
1217
@file{avutil.dll}, and @file{avutil.lib}, respectively. Copy the three
1218
DLLs to your System32 directory (typically @file{C:\Windows\System32}).
1219

    
1220
@end enumerate
1221

    
1222
And here is how to use these libraries with Visual C++:
1223

    
1224
@enumerate
1225

    
1226
@item Create a new console application ("File / New / Project") and then
1227
select "Win32 Console Application". On the appropriate page of the
1228
Application Wizard, uncheck the "Precompiled headers" option.
1229

    
1230
@item Write the source code for your application, or, for testing, just
1231
copy the code from an existing sample application into the source file
1232
that Visual C++ has already created for you. (Note that your source
1233
filehas to have a @code{.cpp} extension; otherwise, Visual C++ won't
1234
compile the FFmpeg headers correctly because in C mode, it doesn't
1235
recognize the @code{inline} keyword.)  For example, you can copy
1236
@file{output_example.c} from the FFmpeg distribution (but you will
1237
have to make minor modifications so the code will compile under
1238
C++, see below).
1239

    
1240
@item Open the "Project / Properties" dialog box. In the "Configuration"
1241
combo box, select "All Configurations" so that the changes you make will
1242
affect both debug and release builds. In the tree view on the left hand
1243
side, select "C/C++ / General", then edit the "Additional Include
1244
Directories" setting to contain the complete paths to the
1245
@file{libavformat}, @file{libavcodec}, and @file{libavutil}
1246
subdirectories of your FFmpeg directory. Note that the directories have
1247
to be separated using semicolons. Now select "Linker / General" from the
1248
tree view and edit the "Additional Library Directories" setting to
1249
contain the same three directories.
1250

    
1251
@item Still in the "Project / Properties" dialog box, select "Linker / Input"
1252
from the tree view, then add the files @file{avformat.lib},
1253
@file{avcodec.lib}, and @file{avutil.lib} to the end of the "Additional
1254
Dependencies". Note that the names of the libraries have to be separated
1255
using spaces.
1256

    
1257
@item Now, select "C/C++ / Code Generation" from the tree view. Select
1258
"Debug" in the "Configuration" combo box. Make sure that "Runtime
1259
Library" is set to "Multi-threaded Debug DLL". Then, select "Release" in
1260
the "Configuration" combo box and make sure that "Runtime Library" is
1261
set to "Multi-threaded DLL".
1262

    
1263
@item Click "OK" to close the "Project / Properties" dialog box and build
1264
the application. Hopefully, it should compile and run cleanly. If you
1265
used @file{output_example.c} as your sample application, you will get a
1266
few compiler errors, but they are easy to fix. The first type of error
1267
occurs because Visual C++ doesn't allow an @code{int} to be converted to
1268
an @code{enum} without a cast. To solve the problem, insert the required
1269
casts (this error occurs once for a @code{CodecID} and once for a
1270
@code{CodecType}).  The second type of error occurs because C++ requires
1271
the return value of @code{malloc} to be cast to the exact type of the
1272
pointer it is being assigned to. Visual C++ will complain that, for
1273
example, @code{(void *)} is being assigned to @code{(uint8_t *)} without
1274
an explicit cast. So insert an explicit cast in these places to silence
1275
the compiler. The third type of error occurs because the @code{snprintf}
1276
library function is called @code{_snprintf} under Visual C++.  So just
1277
add an underscore to fix the problem. With these changes,
1278
@file{output_example.c} should compile under Visual C++, and the
1279
resulting executable should produce valid video files.
1280

    
1281
@end enumerate
1282

    
1283
@subsection Cross compilation for Windows with Linux
1284

    
1285
You must use the MinGW cross compilation tools available at
1286
@url{http://www.mingw.org/}.
1287

    
1288
Then configure FFmpeg with the following options:
1289
@example
1290
./configure --enable-mingw32 --cross-prefix=i386-mingw32msvc-
1291
@end example
1292
(you can change the cross-prefix according to the prefix chosen for the
1293
MinGW tools).
1294

    
1295
Then you can easily test FFmpeg with Wine
1296
(@url{http://www.winehq.com/}).
1297

    
1298
@subsection Compilation under Cygwin
1299

    
1300
Cygwin works very much like Unix.
1301

    
1302
Just install your Cygwin with all the "Base" packages, plus the
1303
following "Devel" ones:
1304
@example
1305
binutils, gcc-core, make, subversion
1306
@end example
1307

    
1308
Do not install binutils-20060709-1 (they are buggy on shared builds);
1309
use binutils-20050610-1 instead.
1310

    
1311
Then run
1312

    
1313
@example
1314
./configure --enable-static --disable-shared
1315
@end example
1316

    
1317
to make a static build or
1318

    
1319
@example
1320
./configure --enable-shared --disable-static
1321
@end example
1322

    
1323
to build shared libraries.
1324

    
1325
If you want to build FFmpeg with additional libraries, download Cygwin
1326
"Devel" packages for Ogg and Vorbis from any Cygwin packages repository
1327
and/or SDL, xvid, faac, faad2 packages from Cygwin Ports,
1328
(@url{http://cygwinports.dotsrc.org/}).
1329

    
1330
@subsection Crosscompilation for Windows under Cygwin
1331

    
1332
With Cygwin you can create Windows binaries that don't need the cygwin1.dll.
1333

    
1334
Just install your Cygwin as explained before, plus these additional
1335
"Devel" packages:
1336
@example
1337
gcc-mingw-core, mingw-runtime, mingw-zlib
1338
@end example
1339

    
1340
and add some special flags to your configure invocation.
1341

    
1342
For a static build run
1343
@example
1344
./configure --enable-mingw32 --enable-memalign-hack --enable-static --disable-shared --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
1345
@end example
1346

    
1347
and for a build with shared libraries
1348
@example
1349
./configure --enable-mingw32 --enable-memalign-hack --enable-shared --disable-static --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
1350
@end example
1351

    
1352
@section BeOS
1353

    
1354
The configure script should guess the configuration itself.
1355
Networking support is currently not finished.
1356
errno issues fixed by Andrew Bachmann.
1357

    
1358
Old stuff:
1359

    
1360
Fran├žois Revol - revol at free dot fr - April 2002
1361

    
1362
The configure script should guess the configuration itself,
1363
however I still didn't test building on the net_server version of BeOS.
1364

    
1365
FFserver is broken (needs poll() implementation).
1366

    
1367
There are still issues with errno codes, which are negative in BeOS, and
1368
that FFmpeg negates when returning. This ends up turning errors into
1369
valid results, then crashes.
1370
(To be fixed)
1371

    
1372
@chapter Developers Guide
1373

    
1374
@section API
1375
@itemize @bullet
1376
@item libavcodec is the library containing the codecs (both encoding and
1377
decoding). Look at @file{libavcodec/apiexample.c} to see how to use it.
1378

    
1379
@item libavformat is the library containing the file format handling (mux and
1380
demux code for several formats). Look at @file{ffplay.c} to use it in a
1381
player. See @file{output_example.c} to use it to generate audio or video
1382
streams.
1383

    
1384
@end itemize
1385

    
1386
@section Integrating libavcodec or libavformat in your program
1387

    
1388
You can integrate all the source code of the libraries to link them
1389
statically to avoid any version problem. All you need is to provide a
1390
'config.mak' and a 'config.h' in the parent directory. See the defines
1391
generated by ./configure to understand what is needed.
1392

    
1393
You can use libavcodec or libavformat in your commercial program, but
1394
@emph{any patch you make must be published}. The best way to proceed is
1395
to send your patches to the FFmpeg mailing list.
1396

    
1397
@node Coding Rules
1398
@section Coding Rules
1399

    
1400
FFmpeg is programmed in the ISO C90 language with a few additional
1401
features from ISO C99, namely:
1402
@itemize @bullet
1403
@item
1404
the @samp{inline} keyword;
1405
@item
1406
@samp{//} comments;
1407
@item
1408
designated struct initializers (@samp{struct s x = @{ .i = 17 @};})
1409
@item
1410
compound literals (@samp{x = (struct s) @{ 17, 23 @};})
1411
@end itemize
1412

    
1413
These features are supported by all compilers we care about, so we won't
1414
accept patches to remove their use unless they absolutely don't impair
1415
clarity and performance.
1416

    
1417
All code must compile with GCC 2.95 and GCC 3.3. Currently, FFmpeg also
1418
compiles with several other compilers, such as the Compaq ccc compiler
1419
or Sun Studio 9, and we would like to keep it that way unless it would
1420
be exceedingly involved. To ensure compatibility, please don't use any
1421
additional C99 features or GCC extensions. Especially watch out for:
1422
@itemize @bullet
1423
@item
1424
mixing statements and declarations;
1425
@item
1426
@samp{long long} (use @samp{int64_t} instead);
1427
@item
1428
@samp{__attribute__} not protected by @samp{#ifdef __GNUC__} or similar;
1429
@item
1430
GCC statement expressions (@samp{(x = (@{ int y = 4; y; @})}).
1431
@end itemize
1432

    
1433
Indent size is 4.
1434
The presentation is the one specified by 'indent -i4 -kr -nut'.
1435
The TAB character is forbidden outside of Makefiles as is any
1436
form of trailing whitespace. Commits containing either will be
1437
rejected by the Subversion repository.
1438

    
1439
Main priority in FFmpeg is simplicity and small code size (=less
1440
bugs).
1441

    
1442
Comments: Use the JavaDoc/Doxygen
1443
format (see examples below) so that code documentation
1444
can be generated automatically. All nontrivial functions should have a comment
1445
above them explaining what the function does, even if it's just one sentence.
1446
All structures and their member variables should be documented, too.
1447
@example
1448
/**
1449
 * @@file mpeg.c
1450
 * MPEG codec.
1451
 * @@author ...
1452
 */
1453

    
1454
/**
1455
 * Summary sentence.
1456
 * more text ...
1457
 * ...
1458
 */
1459
typedef struct Foobar@{
1460
    int var1; /**< var1 description */
1461
    int var2; ///< var2 description
1462
    /** var3 description */
1463
    int var3;
1464
@} Foobar;
1465

    
1466
/**
1467
 * Summary sentence.
1468
 * more text ...
1469
 * ...
1470
 * @@param my_parameter description of my_parameter
1471
 * @@return return value description
1472
 */
1473
int myfunc(int my_parameter)
1474
...
1475
@end example
1476

    
1477
fprintf and printf are forbidden in libavformat and libavcodec,
1478
please use av_log() instead.
1479

    
1480
@section Development Policy
1481

    
1482
@enumerate
1483
@item
1484
   You must not commit code which breaks FFmpeg! (Meaning unfinished but
1485
   enabled code which breaks compilation or compiles but does not work or
1486
   breaks the regression tests)
1487
   You can commit unfinished stuff (for testing etc), but it must be disabled
1488
   (#ifdef etc) by default so it does not interfere with other developers'
1489
   work.
1490
@item
1491
   You don't have to over-test things. If it works for you, and you think it
1492
   should work for others, then commit. If your code has problems
1493
   (portability, triggers compiler bugs, unusual environment etc) they will be
1494
   reported and eventually fixed.
1495
@item
1496
   Do not commit unrelated changes together, split them into self-contained
1497
   pieces.
1498
@item
1499
   Do not change behavior of the program (renaming options etc) without
1500
   first discussing it on the ffmpeg-devel mailing list. Do not remove
1501
   functionality from the code. Just improve!
1502

    
1503
   Note: Redundant code can be removed.
1504
@item
1505
   Do not commit changes to the build system (Makefiles, configure script)
1506
   which change behavior, defaults etc, without asking first. The same
1507
   applies to compiler warning fixes, trivial looking fixes and to code
1508
   maintained by other developers. We usually have a reason for doing things
1509
   the way we do. Send your changes as patches to the ffmpeg-devel mailing
1510
   list, and if the code maintainers say OK, you may commit. This does not
1511
   apply to files you wrote and/or maintain.
1512
@item
1513
   We refuse source indentation and other cosmetic changes if they are mixed
1514
   with functional changes, such commits will be rejected and removed. Every
1515
   developer has his own indentation style, you should not change it. Of course
1516
   if you (re)write something, you can use your own style, even though we would
1517
   prefer if the indentation throughout FFmpeg was consistent (Many projects
1518
   force a given indentation style - we don't.). If you really need to make
1519
   indentation changes (try to avoid this), separate them strictly from real
1520
   changes.
1521

    
1522
   NOTE: If you had to put if()@{ .. @} over a large (> 5 lines) chunk of code,
1523
   then either do NOT change the indentation of the inner part within (don't
1524
   move it to the right)! or do so in a separate commit
1525
@item
1526
   Always fill out the commit log message. Describe in a few lines what you
1527
   changed and why. You can refer to mailing list postings if you fix a
1528
   particular bug. Comments such as "fixed!" or "Changed it." are unacceptable.
1529
@item
1530
   If you apply a patch by someone else, include the name and email address in
1531
   the log message. Since the ffmpeg-cvslog mailing list is publicly
1532
   archived you should add some SPAM protection to the email address. Send an
1533
   answer to ffmpeg-devel (or wherever you got the patch from) saying that
1534
   you applied the patch.
1535
@item
1536
    Do NOT commit to code actively maintained by others without permission.
1537
    Send a patch to ffmpeg-devel instead. If noone answers within a reasonable
1538
    timeframe (12h for build failures and security fixes, 3 days small changes,
1539
    1 week for big patches) then commit your patch if you think it's OK.
1540
    Also note, the maintainer can simply ask for more time to review!
1541
@item
1542
    Subscribe to the ffmpeg-cvslog mailing list. The diffs of all commits
1543
    are sent there and reviewed by all the other developers. Bugs and possible
1544
    improvements or general questions regarding commits are discussed there. We
1545
    expect you to react if problems with your code are uncovered.
1546
@item
1547
    Update the documentation if you change behavior or add features. If you are
1548
    unsure how best to do this, send a patch to ffmpeg-devel, the documentation
1549
    maintainer(s) will review and commit your stuff.
1550
@item
1551
    Never write to unallocated memory, never write over the end of arrays,
1552
    always check values read from some untrusted source before using them
1553
    as array index or other risky things.
1554
@item
1555
    Remember to check if you need to bump versions for the specific libav
1556
    parts (libavutil, libavcodec, libavformat) you are changing. You need
1557
    to change the version integer and the version string.
1558
    Incrementing the first component means no backward compatibility to
1559
    previous versions (e.g. removal of a function from the public API).
1560
    Incrementing the second component means backward compatible change
1561
    (e.g. addition of a function to the public API).
1562
    Incrementing the third component means a noteworthy binary compatible
1563
    change (e.g. encoder bug fix that matters for the decoder).
1564
@item
1565
    If you add a new codec, remember to update the changelog, add it to
1566
    the supported codecs table in the documentation and bump the second
1567
    component of the @file{libavcodec} version number appropriately. If
1568
    it has a fourcc, add it to @file{libavformat/avienc.c}, even if it
1569
    is only a decoder.
1570
@end enumerate
1571

    
1572
We think our rules are not too hard. If you have comments, contact us.
1573

    
1574
Note, these rules are mostly borrowed from the MPlayer project.
1575

    
1576
@section Submitting patches
1577

    
1578
First, (@pxref{Coding Rules}) above if you didn't yet.
1579

    
1580
When you submit your patch, try to send a unified diff (diff '-up'
1581
option). I cannot read other diffs :-)
1582

    
1583
Also please do not submit patches which contain several unrelated changes.
1584
Split them into individual self-contained patches; this makes reviewing
1585
them much easier.
1586

    
1587
Run the regression tests before submitting a patch so that you can
1588
verify that there are no big problems.
1589

    
1590
Patches should be posted as base64 encoded attachments (or any other
1591
encoding which ensures that the patch won't be trashed during
1592
transmission) to the ffmpeg-devel mailing list, see
1593
@url{http://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel}
1594

    
1595
It also helps quite a bit if you tell us what the patch does (for example
1596
'replaces lrint by lrintf'), and why (for example '*BSD isn't C99 compliant
1597
and has no lrint()')
1598

    
1599
We reply to all submitted patches and either apply or reject with some
1600
explanation why, but sometimes we are quite busy so it can take a week or two.
1601

    
1602
@section Regression tests
1603

    
1604
Before submitting a patch (or committing to the repository), you should at least
1605
test that you did not break anything.
1606

    
1607
The regression tests build a synthetic video stream and a synthetic
1608
audio stream. These are then encoded and decoded with all codecs or
1609
formats. The CRC (or MD5) of each generated file is recorded in a
1610
result file. A 'diff' is launched to compare the reference results and
1611
the result file.
1612

    
1613
The regression tests then go on to test the FFserver code with a
1614
limited set of streams. It is important that this step runs correctly
1615
as well.
1616

    
1617
Run 'make test' to test all the codecs and formats.
1618

    
1619
Run 'make fulltest' to test all the codecs, formats and FFserver.
1620

    
1621
[Of course, some patches may change the results of the regression tests. In
1622
this case, the reference results of the regression tests shall be modified
1623
accordingly].
1624

    
1625
@bye