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\input texinfo @c -*- texinfo -*-
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@settitle FFmpeg Documentation
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@titlepage
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@sp 7
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@center @titlefont{FFmpeg Documentation}
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@sp 3
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@end titlepage
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@chapter Introduction
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FFmpeg is a very fast video and audio converter. It can also grab from
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a live audio/video source.
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The command line interface is designed to be intuitive, in the sense
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that FFmpeg tries to figure out all parameters that can possibly be
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derived automatically. You usually only have to specify the target
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bitrate you want.
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FFmpeg can also convert from any sample rate to any other, and resize
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video on the fly with a high quality polyphase filter.
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@chapter Quick Start
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@c man begin EXAMPLES
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@section Video and Audio grabbing
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FFmpeg can use a video4linux compatible video source and any Open Sound
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System audio source:
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@example
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ffmpeg /tmp/out.mpg
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@end example
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Note that you must activate the right video source and channel before
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launching FFmpeg with any TV viewer such as xawtv
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(@url{http://bytesex.org/xawtv/}) by Gerd Knorr. You also
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have to set the audio recording levels correctly with a
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standard mixer.
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@section Video and Audio file format conversion
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* FFmpeg can use any supported file format and protocol as input:
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Examples:
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* You can use YUV files as input:
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@example
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ffmpeg -i /tmp/test%d.Y /tmp/out.mpg
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@end example
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It will use the files:
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@example
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/tmp/test0.Y, /tmp/test0.U, /tmp/test0.V,
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/tmp/test1.Y, /tmp/test1.U, /tmp/test1.V, etc...
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@end example
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The Y files use twice the resolution of the U and V files. They are
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raw files, without header. They can be generated by all decent video
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decoders. You must specify the size of the image with the @option{-s} option
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if FFmpeg cannot guess it.
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* You can input from a raw YUV420P file:
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@example
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ffmpeg -i /tmp/test.yuv /tmp/out.avi
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@end example
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test.yuv is a file containing raw YUV planar data. Each frame is composed
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of the Y plane followed by the U and V planes at half vertical and
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horizontal resolution.
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* You can output to a raw YUV420P file:
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@example
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ffmpeg -i mydivx.avi hugefile.yuv
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@end example
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* You can set several input files and output files:
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@example
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ffmpeg -i /tmp/a.wav -s 640x480 -i /tmp/a.yuv /tmp/a.mpg
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@end example
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Converts the audio file a.wav and the raw YUV video file a.yuv
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to MPEG file a.mpg.
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* You can also do audio and video conversions at the same time:
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@example
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ffmpeg -i /tmp/a.wav -ar 22050 /tmp/a.mp2
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@end example
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Converts a.wav to MPEG audio at 22050Hz sample rate.
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* You can encode to several formats at the same time and define a
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mapping from input stream to output streams:
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@example
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ffmpeg -i /tmp/a.wav -ab 64 /tmp/a.mp2 -ab 128 /tmp/b.mp2 -map 0:0 -map 0:0
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@end example
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Converts a.wav to a.mp2 at 64 kbits and to b.mp2 at 128 kbits. '-map
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file:index' specifies which input stream is used for each output
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stream, in the order of the definition of output streams.
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* You can transcode decrypted VOBs
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@example
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ffmpeg -i snatch_1.vob -f avi -vcodec mpeg4 -b 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 occurence 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} (default = 160x128).
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The following abbreviations are recognized:
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@table @samp
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@item sqcif
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128x96
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@item qcif
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176x144
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@item cif
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352x288
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@item 4cif
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704x576
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@end table
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@item -aspect aspect
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Set aspect ratio (4:3, 16:9 or 1.3333, 1.7777).
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@item -croptop size
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Set top crop band size (in pixels).
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@item -cropbottom size
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Set bottom crop band size (in pixels).
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@item -cropleft size
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Set left crop band size (in pixels).
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@item -cropright size
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Set right crop band size (in pixels).
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@item -padtop size
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Set top pad band size (in pixels).
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@item -padbottom size
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Set bottom pad band size (in pixels).
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@item -padleft size
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Set left pad band size (in pixels).
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@item -padright size
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Set right pad band size (in pixels).
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@item -padcolor (hex color)
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Set color of padded bands. The value for padcolor is expressed
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as a six digit hexadecimal number where the first two digits
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represent red, the middle two digits green and last two digits
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blue (default = 000000 (black)).
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@item -vn
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Disable video recording.
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@item -bt tolerance
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Set video bitrate tolerance (in 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.
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@item -async samples_per_second
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Audio sync method. "Stretches/squeezes" the audio stream to match the timestamps,
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the parameter is the maximum samples per second by which the audio is changed.
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-async 1 is a special case where only the start of the audio stream is corrected
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without any later correction.
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@end table
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@node FFmpeg formula evaluator
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@section FFmpeg formula evaluator
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When evaluating a rate control string, FFmpeg uses an internal formula
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evaluator.
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The following binary operators are available: @code{+}, @code{-},
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@code{*}, @code{/}, @code{^}.
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The following unary operators are available: @code{+}, @code{-},
663
@code{(...)}.
664

    
665
The following functions are available:
666
@table @var
667
@item sinh(x)
668
@item cosh(x)
669
@item tanh(x)
670
@item sin(x)
671
@item cos(x)
672
@item tan(x)
673
@item exp(x)
674
@item log(x)
675
@item squish(x)
676
@item gauss(x)
677
@item abs(x)
678
@item max(x, y)
679
@item min(x, y)
680
@item gt(x, y)
681
@item lt(x, y)
682
@item eq(x, y)
683
@item bits2qp(bits)
684
@item qp2bits(qp)
685
@end table
686

    
687
The following constants are available:
688
@table @var
689
@item PI
690
@item E
691
@item iTex
692
@item pTex
693
@item tex
694
@item mv
695
@item fCode
696
@item iCount
697
@item mcVar
698
@item var
699
@item isI
700
@item isP
701
@item isB
702
@item avgQP
703
@item qComp
704
@item avgIITex
705
@item avgPITex
706
@item avgPPTex
707
@item avgBPTex
708
@item avgTex
709
@end table
710

    
711
@c man end
712

    
713
@ignore
714

    
715
@setfilename ffmpeg
716
@settitle FFmpeg video converter
717

    
718
@c man begin SEEALSO
719
ffserver(1), ffplay(1) and the HTML documentation of @file{ffmpeg}.
720
@c man end
721

    
722
@c man begin AUTHOR
723
Fabrice Bellard
724
@c man end
725

    
726
@end ignore
727

    
728
@section Protocols
729

    
730
The filename can be @file{-} to read from standard input or to write
731
to standard output.
732

    
733
FFmpeg also handles many protocols specified with an URL syntax.
734

    
735
Use 'ffmpeg -formats' to see a list of the supported protocols.
736

    
737
The protocol @code{http:} is currently used only to communicate with
738
FFserver (see the FFserver documentation). When FFmpeg will be a
739
video player it will also be used for streaming :-)
740

    
741
@chapter Tips
742

    
743
@itemize
744
@item For streaming at very low bitrate application, use a low frame rate
745
and a small GOP size. This is especially true for RealVideo where
746
the Linux player does not seem to be very fast, so it can miss
747
frames. An example is:
748

    
749
@example
750
ffmpeg -g 3 -r 3 -t 10 -b 50k -s qcif -f rv10 /tmp/b.rm
751
@end example
752

    
753
@item  The parameter 'q' which is displayed while encoding is the current
754
quantizer. The value 1 indicates that a very good quality could
755
be achieved. The value 31 indicates the worst quality. If q=31 appears
756
too often, it means that the encoder cannot compress enough to meet
757
your bitrate. You must either increase the bitrate, decrease the
758
frame rate or decrease the frame size.
759

    
760
@item If your computer is not fast enough, you can speed up the
761
compression at the expense of the compression ratio. You can use
762
'-me zero' to speed up motion estimation, and '-intra' to disable
763
motion estimation completely (you have only I-frames, which means it
764
is about as good as JPEG compression).
765

    
766
@item To have very low audio bitrates, reduce the sampling frequency
767
(down to 22050 kHz for MPEG audio, 22050 or 11025 for AC3).
768

    
769
@item To have a constant quality (but a variable bitrate), use the option
770
'-qscale n' when 'n' is between 1 (excellent quality) and 31 (worst
771
quality).
772

    
773
@item When converting video files, you can use the '-sameq' option which
774
uses the same quality factor in the encoder as in the decoder.
775
It allows almost lossless encoding.
776

    
777
@end itemize
778

    
779

    
780
@chapter external libraries
781

    
782
FFmpeg can be hooked up with a number of external libraries to add support
783
for more formats.
784

    
785
@section AMR
786

    
787
AMR comes in two different flavors, WB and NB. FFmpeg can make use of the
788
AMR WB (floating-point mode) and the AMR NB (both floating-point and
789
fixed-point mode) reference decoders and encoders.
790

    
791
@itemize
792

    
793
@item For AMR WB floating-point download TS26.204 V5.1.0 from
794
@url{http://www.3gpp.org/ftp/Specs/archive/26_series/26.204/26204-510.zip}
795
and extract the source to @file{libavcodec/amrwb_float/}.
796

    
797
@item For AMR NB floating-point download TS26.104 REL-5 V5.1.0 from
798
@url{http://www.3gpp.org/ftp/Specs/archive/26_series/26.104/26104-510.zip}
799
and extract the source to @file{libavcodec/amr_float/}.
800
If you try this on Alpha, you may need to change @code{Word32} to
801
@code{int} in @file{amr/typedef.h}.
802

    
803
@item For AMR NB fixed-point download TS26.073 REL-5 V5.1.0 from
804
@url{http://www.3gpp.org/ftp/Specs/archive/26_series/26.073/26073-510.zip}
805
and extract the source to @file{libavcodec/amr}.
806
You must also add @code{-DMMS_IO} and remove @code{-pedantic-errors}
807
to/from @code{CFLAGS} in @file{libavcodec/amr/makefile}, i.e.
808
``@code{CFLAGS = -Wall -I. \$(CFLAGS_\$(MODE)) -D\$(VAD) -DMMS_IO}''.
809

    
810
@end itemize
811

    
812

    
813
@chapter Supported File Formats and Codecs
814

    
815
You can use the @code{-formats} option to have an exhaustive list.
816

    
817
@section File Formats
818

    
819
FFmpeg supports the following file formats through the @code{libavformat}
820
library:
821

    
822
@multitable @columnfractions .4 .1 .1 .4
823
@item Supported File Format @tab Encoding @tab Decoding @tab Comments
824
@item MPEG audio @tab X @tab X
825
@item MPEG-1 systems @tab X  @tab  X
826
@tab muxed audio and video
827
@item MPEG-2 PS @tab X  @tab  X
828
@tab also known as @code{VOB} file
829
@item MPEG-2 TS @tab    @tab  X
830
@tab also known as DVB Transport Stream
831
@item ASF@tab X @tab X
832
@item AVI@tab X @tab X
833
@item WAV@tab X @tab X
834
@item Macromedia Flash@tab X @tab X
835
@tab Only embedded audio is decoded.
836
@item FLV              @tab  X @tab X
837
@tab Macromedia Flash video files
838
@item Real Audio and Video @tab X @tab X
839
@item Raw AC3 @tab X  @tab  X
840
@item Raw MJPEG @tab X  @tab  X
841
@item Raw MPEG video @tab X  @tab  X
842
@item Raw PCM8/16 bits, mulaw/Alaw@tab X  @tab  X
843
@item Raw CRI ADX audio @tab X  @tab  X
844
@item Raw Shorten audio @tab    @tab  X
845
@item SUN AU format @tab X  @tab  X
846
@item NUT @tab X @tab X @tab NUT Open Container Format
847
@item QuickTime        @tab X @tab  X
848
@item MPEG-4           @tab X @tab  X
849
@tab MPEG-4 is a variant of QuickTime.
850
@item Raw MPEG4 video  @tab  X @tab  X
851
@item DV               @tab  X @tab  X
852
@item 4xm              @tab    @tab X
853
@tab 4X Technologies format, used in some games.
854
@item Playstation STR  @tab    @tab X
855
@item Id RoQ           @tab    @tab X
856
@tab Used in Quake III, Jedi Knight 2, other computer games.
857
@item Interplay MVE    @tab    @tab X
858
@tab Format used in various Interplay computer games.
859
@item WC3 Movie        @tab    @tab X
860
@tab Multimedia format used in Origin's Wing Commander III computer game.
861
@item Sega FILM/CPK    @tab    @tab X
862
@tab Used in many Sega Saturn console games.
863
@item Westwood Studios VQA/AUD  @tab    @tab X
864
@tab Multimedia formats used in Westwood Studios games.
865
@item Id Cinematic (.cin) @tab    @tab X
866
@tab Used in Quake II.
867
@item FLIC format      @tab    @tab X
868
@tab .fli/.flc files
869
@item Sierra VMD       @tab    @tab X
870
@tab Used in Sierra CD-ROM games.
871
@item Sierra Online    @tab    @tab X
872
@tab .sol files used in Sierra Online games.
873
@item Matroska         @tab    @tab X
874
@item Electronic Arts Multimedia    @tab    @tab X
875
@tab Used in various EA games; files have extensions like WVE and UV2.
876
@item Nullsoft Video (NSV) format @tab    @tab X
877
@item ADTS AAC audio @tab X @tab X
878
@item Creative VOC @tab X @tab X @tab Created for the Sound Blaster Pro.
879
@item American Laser Games MM  @tab    @tab X
880
@tab Multimedia format used in games like Mad Dog McCree
881
@item AVS @tab    @tab X
882
@tab Multimedia format used by the Creature Shock game.
883
@item Smacker @tab    @tab X
884
@tab Multimedia format used by many games.
885
@item GXF @tab  X @tab X
886
@tab General eXchange Format SMPTE 360M, used by Thomson Grass Valley playout servers.
887
@item CIN @tab    @tab X
888
@tab Multimedia format used by Delphine Software games.
889
@item MXF @tab    @tab X
890
@tab Material eXchange Format SMPTE 377M, used by D-Cinema, broadcast industry.
891
@item SEQ @tab    @tab X
892
@tab Tiertex .seq files used in the DOS CDROM version of the game Flashback.
893
@end multitable
894

    
895
@code{X} means that encoding (resp. decoding) is supported.
896

    
897
@section Image Formats
898

    
899
FFmpeg can read and write images for each frame of a video sequence. The
900
following image formats are supported:
901

    
902
@multitable @columnfractions .4 .1 .1 .4
903
@item Supported Image Format @tab Encoding @tab Decoding @tab Comments
904
@item PGM, PPM     @tab X @tab X
905
@item PAM          @tab X @tab X @tab PAM is a PNM extension with alpha support.
906
@item PGMYUV       @tab X @tab X @tab PGM with U and V components in YUV 4:2:0
907
@item JPEG         @tab X @tab X @tab Progressive JPEG is not supported.
908
@item .Y.U.V       @tab X @tab X @tab one raw file per component
909
@item animated GIF @tab X @tab X @tab Only uncompressed GIFs are generated.
910
@item PNG          @tab X @tab X @tab 2 bit and 4 bit/pixel not supported yet.
911
@item Targa        @tab   @tab X @tab Targa (.TGA) image format.
912
@item TIFF         @tab   @tab X @tab Only 24 bit/pixel images are supported.
913
@item SGI          @tab X @tab X @tab SGI RGB image format
914
@end multitable
915

    
916
@code{X} means that encoding (resp. decoding) is supported.
917

    
918
@section Video Codecs
919

    
920
@multitable @columnfractions .4 .1 .1 .4
921
@item Supported Codec @tab Encoding @tab Decoding @tab Comments
922
@item MPEG-1 video           @tab  X  @tab  X
923
@item MPEG-2 video           @tab  X  @tab  X
924
@item MPEG-4                 @tab  X  @tab  X
925
@item MSMPEG4 V1             @tab  X  @tab  X
926
@item MSMPEG4 V2             @tab  X  @tab  X
927
@item MSMPEG4 V3             @tab  X  @tab  X
928
@item WMV7                   @tab  X  @tab  X
929
@item WMV8                   @tab  X  @tab  X @tab not completely working
930
@item WMV9                   @tab     @tab  X @tab not completely working
931
@item VC1                    @tab     @tab  X
932
@item H.261                  @tab  X  @tab  X
933
@item H.263(+)               @tab  X  @tab  X @tab also known as RealVideo 1.0
934
@item H.264                  @tab     @tab  X
935
@item RealVideo 1.0          @tab  X  @tab  X
936
@item RealVideo 2.0          @tab  X  @tab  X
937
@item MJPEG                  @tab  X  @tab  X
938
@item lossless MJPEG         @tab  X  @tab  X
939
@item JPEG-LS                @tab  X  @tab  X @tab fourcc: MJLS, lossless and near-lossless is supported
940
@item Apple MJPEG-B          @tab     @tab  X
941
@item Sunplus MJPEG          @tab     @tab  X @tab fourcc: SP5X
942
@item DV                     @tab  X  @tab  X
943
@item HuffYUV                @tab  X  @tab  X
944
@item FFmpeg Video 1         @tab  X  @tab  X @tab experimental lossless codec (fourcc: FFV1)
945
@item FFmpeg Snow            @tab  X  @tab  X @tab experimental wavelet codec (fourcc: SNOW)
946
@item Asus v1                @tab  X  @tab  X @tab fourcc: ASV1
947
@item Asus v2                @tab  X  @tab  X @tab fourcc: ASV2
948
@item Creative YUV           @tab     @tab  X @tab fourcc: CYUV
949
@item Sorenson Video 1       @tab  X  @tab  X @tab fourcc: SVQ1
950
@item Sorenson Video 3       @tab     @tab  X @tab fourcc: SVQ3
951
@item On2 VP3                @tab     @tab  X @tab still experimental
952
@item On2 VP5                @tab     @tab  X @tab fourcc: VP50
953
@item On2 VP6                @tab     @tab  X @tab fourcc: VP62
954
@item Theora                 @tab     @tab  X @tab still experimental
955
@item Intel Indeo 3          @tab     @tab  X
956
@item FLV                    @tab  X  @tab  X @tab Sorenson H.263 used in Flash
957
@item Flash Screen Video     @tab     @tab  X @tab fourcc: FSV1
958
@item ATI VCR1               @tab     @tab  X @tab fourcc: VCR1
959
@item ATI VCR2               @tab     @tab  X @tab fourcc: VCR2
960
@item Cirrus Logic AccuPak   @tab     @tab  X @tab fourcc: CLJR
961
@item 4X Video               @tab     @tab  X @tab Used in certain computer games.
962
@item Sony Playstation MDEC  @tab     @tab  X
963
@item Id RoQ                 @tab     @tab  X @tab Used in Quake III, Jedi Knight 2, other computer games.
964
@item Xan/WC3                @tab     @tab  X @tab Used in Wing Commander III .MVE files.
965
@item Interplay Video        @tab     @tab  X @tab Used in Interplay .MVE files.
966
@item Apple Animation        @tab     @tab  X @tab fourcc: 'rle '
967
@item Apple Graphics         @tab     @tab  X @tab fourcc: 'smc '
968
@item Apple Video            @tab     @tab  X @tab fourcc: rpza
969
@item Apple QuickDraw        @tab     @tab  X @tab fourcc: qdrw
970
@item Cinepak                @tab     @tab  X
971
@item Microsoft RLE          @tab     @tab  X
972
@item Microsoft Video-1      @tab     @tab  X
973
@item Westwood VQA           @tab     @tab  X
974
@item Id Cinematic Video     @tab     @tab  X @tab Used in Quake II.
975
@item Planar RGB             @tab     @tab  X @tab fourcc: 8BPS
976
@item FLIC video             @tab     @tab  X
977
@item Duck TrueMotion v1     @tab     @tab  X @tab fourcc: DUCK
978
@item Duck TrueMotion v2     @tab     @tab  X @tab fourcc: TM20
979
@item VMD Video              @tab     @tab  X @tab Used in Sierra VMD files.
980
@item MSZH                   @tab     @tab  X @tab Part of LCL
981
@item ZLIB                   @tab  X  @tab  X @tab Part of LCL, encoder experimental
982
@item TechSmith Camtasia     @tab     @tab  X @tab fourcc: TSCC
983
@item IBM Ultimotion         @tab     @tab  X @tab fourcc: ULTI
984
@item Miro VideoXL           @tab     @tab  X @tab fourcc: VIXL
985
@item QPEG                   @tab     @tab  X @tab fourccs: QPEG, Q1.0, Q1.1
986
@item LOCO                   @tab     @tab  X @tab
987
@item Winnov WNV1            @tab     @tab  X @tab
988
@item Autodesk Animator Studio Codec  @tab     @tab  X @tab fourcc: AASC
989
@item Fraps FPS1             @tab     @tab  X @tab
990
@item CamStudio              @tab     @tab  X @tab fourcc: CSCD
991
@item American Laser Games Video  @tab    @tab X @tab Used in games like Mad Dog McCree
992
@item ZMBV                   @tab     @tab  X @tab
993
@item AVS Video              @tab     @tab  X @tab Video encoding used by the Creature Shock game.
994
@item Smacker Video          @tab     @tab  X @tab Video encoding used in Smacker.
995
@item RTjpeg                 @tab     @tab  X @tab Video encoding used in NuppelVideo files.
996
@item KMVC                   @tab     @tab  X @tab Codec used in Worms games.
997
@item VMware Video           @tab     @tab  X @tab Codec used in videos captured by VMware.
998
@item Cin Video              @tab     @tab  X @tab Codec used in Delphine Software games.
999
@item Tiertex Seq Video      @tab     @tab  X @tab Codec used in DOS CDROM FlashBack game.
1000
@end multitable
1001

    
1002
@code{X} means that encoding (resp. decoding) is supported.
1003

    
1004
@section Audio Codecs
1005

    
1006
@multitable @columnfractions .4 .1 .1 .1 .7
1007
@item Supported Codec @tab Encoding @tab Decoding @tab Comments
1008
@item MPEG audio layer 2     @tab  IX  @tab  IX
1009
@item MPEG audio layer 1/3   @tab IX   @tab  IX
1010
@tab MP3 encoding is supported through the external library LAME.
1011
@item AC3                    @tab  IX  @tab  IX
1012
@tab liba52 is used internally for decoding.
1013
@item Vorbis                 @tab  X   @tab  X
1014
@item WMA V1/V2              @tab      @tab X
1015
@item AAC                    @tab X    @tab X
1016
@tab Supported through the external library libfaac/libfaad.
1017
@item Microsoft ADPCM        @tab X    @tab X
1018
@item MS IMA ADPCM           @tab X    @tab X
1019
@item QT IMA ADPCM           @tab      @tab X
1020
@item 4X IMA ADPCM           @tab      @tab X
1021
@item G.726  ADPCM           @tab X    @tab X
1022
@item Duck DK3 IMA ADPCM     @tab      @tab X
1023
@tab Used in some Sega Saturn console games.
1024
@item Duck DK4 IMA ADPCM     @tab      @tab X
1025
@tab Used in some Sega Saturn console games.
1026
@item Westwood Studios IMA ADPCM @tab      @tab X
1027
@tab Used in Westwood Studios games like Command and Conquer.
1028
@item SMJPEG IMA ADPCM       @tab      @tab X
1029
@tab Used in certain Loki game ports.
1030
@item CD-ROM XA ADPCM        @tab      @tab X
1031
@item CRI ADX ADPCM          @tab X    @tab X
1032
@tab Used in Sega Dreamcast games.
1033
@item Electronic Arts ADPCM  @tab      @tab X
1034
@tab Used in various EA titles.
1035
@item Creative ADPCM         @tab      @tab X
1036
@tab 16 -> 4, 8 -> 4, 8 -> 3, 8 -> 2
1037
@item RA144                  @tab      @tab X
1038
@tab Real 14400 bit/s codec
1039
@item RA288                  @tab      @tab X
1040
@tab Real 28800 bit/s codec
1041
@item RADnet                 @tab X    @tab IX
1042
@tab Real low bitrate AC3 codec, liba52 is used for decoding.
1043
@item AMR-NB                 @tab X    @tab X
1044
@tab Supported through an external library.
1045
@item AMR-WB                 @tab X    @tab X
1046
@tab Supported through an external library.
1047
@item DV audio               @tab      @tab X
1048
@item Id RoQ DPCM            @tab      @tab X
1049
@tab Used in Quake III, Jedi Knight 2, other computer games.
1050
@item Interplay MVE DPCM     @tab      @tab X
1051
@tab Used in various Interplay computer games.
1052
@item Xan DPCM               @tab      @tab X
1053
@tab Used in Origin's Wing Commander IV AVI files.
1054
@item Sierra Online DPCM     @tab      @tab X
1055
@tab Used in Sierra Online game audio files.
1056
@item Apple MACE 3           @tab      @tab X
1057
@item Apple MACE 6           @tab      @tab X
1058
@item FLAC lossless audio    @tab      @tab X
1059
@item Shorten lossless audio @tab      @tab X
1060
@item Apple lossless audio   @tab      @tab X
1061
@tab QuickTime fourcc 'alac'
1062
@item FFmpeg Sonic           @tab X    @tab X
1063
@tab experimental lossy/lossless codec
1064
@item Qdesign QDM2           @tab      @tab X
1065
@tab there are still some distortions
1066
@item Real COOK              @tab      @tab X
1067
@tab All versions except 5.1 are supported
1068
@item DSP Group TrueSpeech   @tab      @tab X
1069
@item True Audio (TTA)       @tab      @tab X
1070
@item Smacker Audio          @tab      @tab X
1071
@item WavPack Audio          @tab      @tab X
1072
@item Cin Audio              @tab      @tab X
1073
@tab Codec used in Delphine Software games.
1074
@item Intel Music Coder      @tab      @tab X
1075
@end multitable
1076

    
1077
@code{X} means that encoding (resp. decoding) is supported.
1078

    
1079
@code{I} means that an integer-only version is available, too (ensures high
1080
performance on systems without hardware floating point support).
1081

    
1082
@chapter Platform Specific information
1083

    
1084
@section Linux
1085

    
1086
FFmpeg should be compiled with at least GCC 2.95.3. GCC 3.2 is the
1087
preferred compiler now for FFmpeg. All future optimizations will depend on
1088
features only found in GCC 3.2.
1089

    
1090
@section BSD
1091

    
1092
BSD make will not build FFmpeg, you need to install and use GNU Make
1093
(@file{gmake}).
1094

    
1095
@section Windows
1096

    
1097
@subsection Native Windows compilation
1098

    
1099
@itemize
1100
@item Install the current versions of MSYS and MinGW from
1101
@url{http://www.mingw.org/}. You can find detailed installation
1102
instructions in the download section and the FAQ.
1103

    
1104
@item If you want to test the FFplay, also download
1105
the MinGW development library of SDL 1.2.x
1106
(@file{SDL-devel-1.2.x-mingw32.tar.gz}) from
1107
@url{http://www.libsdl.org}. Unpack it in a temporary directory, and
1108
unpack the archive @file{i386-mingw32msvc.tar.gz} in the MinGW tool
1109
directory. Edit the @file{sdl-config} script so that it gives the
1110
correct SDL directory when invoked.
1111

    
1112
@item Extract the current version of FFmpeg.
1113

    
1114
@item Start the MSYS shell (file @file{msys.bat}).
1115

    
1116
@item Change to the FFmpeg directory and follow
1117
 the instructions of how to compile FFmpeg (file
1118
@file{INSTALL}). Usually, launching @file{./configure} and @file{make}
1119
suffices. If you have problems using SDL, verify that
1120
@file{sdl-config} can be launched from the MSYS command line.
1121

    
1122
@item You can install FFmpeg in @file{Program Files/FFmpeg} by typing
1123
@file{make install}. Don't forget to copy @file{SDL.dll} to the place
1124
you launch @file{ffplay} from.
1125

    
1126
@end itemize
1127

    
1128
Notes:
1129
@itemize
1130

    
1131
@item The target @file{make wininstaller} can be used to create a
1132
Nullsoft based Windows installer for FFmpeg and FFplay. @file{SDL.dll}
1133
must be copied to the FFmpeg directory in order to build the
1134
installer.
1135

    
1136
@item By using @code{./configure --enable-shared} when configuring FFmpeg,
1137
you can build @file{avcodec.dll} and @file{avformat.dll}. With
1138
@code{make install} you install the FFmpeg DLLs and the associated
1139
headers in @file{Program Files/FFmpeg}.
1140

    
1141
@item Visual C++ compatibility: If you used @code{./configure --enable-shared}
1142
when configuring FFmpeg, FFmpeg tries to use the Microsoft Visual
1143
C++ @code{lib} tool to build @code{avcodec.lib} and
1144
@code{avformat.lib}. With these libraries you can link your Visual C++
1145
code directly with the FFmpeg DLLs (see below).
1146

    
1147
@end itemize
1148

    
1149
@subsection Visual C++ compatibility
1150

    
1151
FFmpeg will not compile under Visual C++ -- and it has too many
1152
dependencies on the GCC compiler to make a port viable. However,
1153
if you want to use the FFmpeg libraries in your own applications,
1154
you can still compile those applications using Visual C++. An
1155
important restriction to this is that you have to use the
1156
dynamically linked versions of the FFmpeg libraries (i.e. the
1157
DLLs), and you have to make sure that Visual-C++-compatible
1158
import libraries are created during the FFmpeg build process.
1159

    
1160
This description of how to use the FFmpeg libraries with Visual C++ is
1161
based on Visual C++ 2005 Express Edition Beta 2. If you have a different
1162
version, you might have to modify the procedures slightly.
1163

    
1164
Here are the step-by-step instructions for building the FFmpeg libraries
1165
so they can be used with Visual C++:
1166

    
1167
@enumerate
1168

    
1169
@item Install Visual C++ (if you haven't done so already).
1170

    
1171
@item Install MinGW and MSYS as described above.
1172

    
1173
@item Add a call to @file{vcvars32.bat} (which sets up the environment
1174
variables for the Visual C++ tools) as the first line of
1175
@file{msys.bat}. The standard location for @file{vcvars32.bat} is
1176
@file{C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat},
1177
and the standard location for @file{msys.bat} is
1178
@file{C:\msys\1.0\msys.bat}. If this corresponds to your setup, add the
1179
following line as the first line of @file{msys.bat}:
1180

    
1181
@code{call "C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat"}
1182

    
1183
@item Start the MSYS shell (file @file{msys.bat}) and type @code{link.exe}.
1184
If you get a help message with the command line options of @code{link.exe},
1185
this means your environment variables are set up correctly, the
1186
Microsoft linker is on the path and will be used by FFmpeg to
1187
create Visual-C++-compatible import libraries.
1188

    
1189
@item Extract the current version of FFmpeg and change to the FFmpeg directory.
1190

    
1191
@item Type the command
1192
@code{./configure --enable-shared --disable-static --enable-memalign-hack}
1193
to configure and, if that didn't produce any errors,
1194
type @code{make} to build FFmpeg.
1195

    
1196
@item The subdirectories @file{libavformat}, @file{libavcodec}, and
1197
@file{libavutil} should now contain the files @file{avformat.dll},
1198
@file{avformat.lib}, @file{avcodec.dll}, @file{avcodec.lib},
1199
@file{avutil.dll}, and @file{avutil.lib}, respectively. Copy the three
1200
DLLs to your System32 directory (typically @file{C:\Windows\System32}).
1201

    
1202
@end enumerate
1203

    
1204
And here is how to use these libraries with Visual C++:
1205

    
1206
@enumerate
1207

    
1208
@item Create a new console application ("File / New / Project") and then
1209
select "Win32 Console Application". On the appropriate page of the
1210
Application Wizard, uncheck the "Precompiled headers" option.
1211

    
1212
@item Write the source code for your application, or, for testing, just
1213
copy the code from an existing sample application into the source file
1214
that Visual C++ has already created for you. (Note that your source
1215
filehas to have a @code{.cpp} extension; otherwise, Visual C++ won't
1216
compile the FFmpeg headers correctly because in C mode, it doesn't
1217
recognize the @code{inline} keyword.)  For example, you can copy
1218
@file{output_example.c} from the FFmpeg distribution (but you will
1219
have to make minor modifications so the code will compile under
1220
C++, see below).
1221

    
1222
@item Open the "Project / Properties" dialog box. In the "Configuration"
1223
combo box, select "All Configurations" so that the changes you make will
1224
affect both debug and release builds. In the tree view on the left hand
1225
side, select "C/C++ / General", then edit the "Additional Include
1226
Directories" setting to contain the complete paths to the
1227
@file{libavformat}, @file{libavcodec}, and @file{libavutil}
1228
subdirectories of your FFmpeg directory. Note that the directories have
1229
to be separated using semicolons. Now select "Linker / General" from the
1230
tree view and edit the "Additional Library Directories" setting to
1231
contain the same three directories.
1232

    
1233
@item Still in the "Project / Properties" dialog box, select "Linker / Input"
1234
from the tree view, then add the files @file{avformat.lib},
1235
@file{avcodec.lib}, and @file{avutil.lib} to the end of the "Additional
1236
Dependencies". Note that the names of the libraries have to be separated
1237
using spaces.
1238

    
1239
@item Now, select "C/C++ / Code Generation" from the tree view. Select
1240
"Debug" in the "Configuration" combo box. Make sure that "Runtime
1241
Library" is set to "Multi-threaded Debug DLL". Then, select "Release" in
1242
the "Configuration" combo box and make sure that "Runtime Library" is
1243
set to "Multi-threaded DLL".
1244

    
1245
@item Click "OK" to close the "Project / Properties" dialog box and build
1246
the application. Hopefully, it should compile and run cleanly. If you
1247
used @file{output_example.c} as your sample application, you will get a
1248
few compiler errors, but they are easy to fix. The first type of error
1249
occurs because Visual C++ doesn't allow an @code{int} to be converted to
1250
an @code{enum} without a cast. To solve the problem, insert the required
1251
casts (this error occurs once for a @code{CodecID} and once for a
1252
@code{CodecType}).  The second type of error occurs because C++ requires
1253
the return value of @code{malloc} to be cast to the exact type of the
1254
pointer it is being assigned to. Visual C++ will complain that, for
1255
example, @code{(void *)} is being assigned to @code{(uint8_t *)} without
1256
an explicit cast. So insert an explicit cast in these places to silence
1257
the compiler. The third type of error occurs because the @code{snprintf}
1258
library function is called @code{_snprintf} under Visual C++.  So just
1259
add an underscore to fix the problem. With these changes,
1260
@file{output_example.c} should compile under Visual C++, and the
1261
resulting executable should produce valid video files.
1262

    
1263
@end enumerate
1264

    
1265
@subsection Cross compilation for Windows with Linux
1266

    
1267
You must use the MinGW cross compilation tools available at
1268
@url{http://www.mingw.org/}.
1269

    
1270
Then configure FFmpeg with the following options:
1271
@example
1272
./configure --enable-mingw32 --cross-prefix=i386-mingw32msvc-
1273
@end example
1274
(you can change the cross-prefix according to the prefix chosen for the
1275
MinGW tools).
1276

    
1277
Then you can easily test FFmpeg with Wine
1278
(@url{http://www.winehq.com/}).
1279

    
1280
@subsection Compilation under Cygwin
1281

    
1282
Cygwin works very much like Unix.
1283

    
1284
Just install your Cygwin with all the "Base" packages, plus the
1285
following "Devel" ones:
1286
@example
1287
binutils, gcc-core, make, subversion
1288
@end example
1289

    
1290
Do not install binutils-20060709-1 (they are buggy on shared builds);
1291
use binutils-20050610-1 instead.
1292

    
1293
Then run
1294

    
1295
@example
1296
./configure --enable-static --disable-shared
1297
@end example
1298

    
1299
to make a static build or
1300

    
1301
@example
1302
./configure --enable-shared --disable-static
1303
@end example
1304

    
1305
to build shared libraries.
1306

    
1307
If you want to build FFmpeg with additional libraries, download Cygwin
1308
"Devel" packages for Ogg and Vorbis from any Cygwin packages repository
1309
and/or SDL, xvid, faac, faad2 packages from Cygwin Ports,
1310
(@url{http://cygwinports.dotsrc.org/}).
1311

    
1312
@subsection Crosscompilation for Windows under Cygwin
1313

    
1314
With Cygwin you can create Windows binaries that don't need the cygwin1.dll.
1315

    
1316
Just install your Cygwin as explained before, plus these additional
1317
"Devel" packages:
1318
@example
1319
gcc-mingw-core, mingw-runtime, mingw-zlib
1320
@end example
1321

    
1322
and add some special flags to your configure invocation.
1323

    
1324
For a static build run
1325
@example
1326
./configure --enable-mingw32 --enable-memalign-hack --enable-static --disable-shared --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
1327
@end example
1328

    
1329
and for a build with shared libraries
1330
@example
1331
./configure --enable-mingw32 --enable-memalign-hack --enable-shared --disable-static --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
1332
@end example
1333

    
1334
@section BeOS
1335

    
1336
The configure script should guess the configuration itself.
1337
Networking support is currently not finished.
1338
errno issues fixed by Andrew Bachmann.
1339

    
1340
Old stuff:
1341

    
1342
Fran├žois Revol - revol at free dot fr - April 2002
1343

    
1344
The configure script should guess the configuration itself,
1345
however I still didn't test building on the net_server version of BeOS.
1346

    
1347
FFserver is broken (needs poll() implementation).
1348

    
1349
There are still issues with errno codes, which are negative in BeOS, and
1350
that FFmpeg negates when returning. This ends up turning errors into
1351
valid results, then crashes.
1352
(To be fixed)
1353

    
1354
@chapter Developers Guide
1355

    
1356
@section API
1357
@itemize @bullet
1358
@item libavcodec is the library containing the codecs (both encoding and
1359
decoding). Look at @file{libavcodec/apiexample.c} to see how to use it.
1360

    
1361
@item libavformat is the library containing the file format handling (mux and
1362
demux code for several formats). Look at @file{ffplay.c} to use it in a
1363
player. See @file{output_example.c} to use it to generate audio or video
1364
streams.
1365

    
1366
@end itemize
1367

    
1368
@section Integrating libavcodec or libavformat in your program
1369

    
1370
You can integrate all the source code of the libraries to link them
1371
statically to avoid any version problem. All you need is to provide a
1372
'config.mak' and a 'config.h' in the parent directory. See the defines
1373
generated by ./configure to understand what is needed.
1374

    
1375
You can use libavcodec or libavformat in your commercial program, but
1376
@emph{any patch you make must be published}. The best way to proceed is
1377
to send your patches to the FFmpeg mailing list.
1378

    
1379
@node Coding Rules
1380
@section Coding Rules
1381

    
1382
FFmpeg is programmed in the ISO C90 language with a few additional
1383
features from ISO C99, namely:
1384
@itemize @bullet
1385
@item
1386
the @samp{inline} keyword;
1387
@item
1388
@samp{//} comments;
1389
@item
1390
designated struct initializers (@samp{struct s x = @{ .i = 17 @};})
1391
@item
1392
compound literals (@samp{x = (struct s) @{ 17, 23 @};})
1393
@end itemize
1394

    
1395
These features are supported by all compilers we care about, so we won't
1396
accept patches to remove their use unless they absolutely don't impair
1397
clarity and performance.
1398

    
1399
All code must compile with GCC 2.95 and GCC 3.3. Currently, FFmpeg also
1400
compiles with several other compilers, such as the Compaq ccc compiler
1401
or Sun Studio 9, and we would like to keep it that way unless it would
1402
be exceedingly involved. To ensure compatibility, please don't use any
1403
additional C99 features or GCC extensions. Especially watch out for:
1404
@itemize @bullet
1405
@item
1406
mixing statements and declarations;
1407
@item
1408
@samp{long long} (use @samp{int64_t} instead);
1409
@item
1410
@samp{__attribute__} not protected by @samp{#ifdef __GNUC__} or similar;
1411
@item
1412
GCC statement expressions (@samp{(x = (@{ int y = 4; y; @})}).
1413
@end itemize
1414

    
1415
Indent size is 4.
1416
The presentation is the one specified by 'indent -i4 -kr -nut'.
1417
The TAB character is forbidden outside of Makefiles as is any
1418
form of trailing whitespace. Commits containing either will be
1419
rejected by the Subversion repository.
1420

    
1421
Main priority in FFmpeg is simplicity and small code size (=less
1422
bugs).
1423

    
1424
Comments: Use the JavaDoc/Doxygen
1425
format (see examples below) so that code documentation
1426
can be generated automatically. All nontrivial functions should have a comment
1427
above them explaining what the function does, even if it's just one sentence.
1428
All structures and their member variables should be documented, too.
1429
@example
1430
/**
1431
 * @@file mpeg.c
1432
 * MPEG codec.
1433
 * @@author ...
1434
 */
1435

    
1436
/**
1437
 * Summary sentence.
1438
 * more text ...
1439
 * ...
1440
 */
1441
typedef struct Foobar@{
1442
    int var1; /**< var1 description */
1443
    int var2; ///< var2 description
1444
    /** var3 description */
1445
    int var3;
1446
@} Foobar;
1447

    
1448
/**
1449
 * Summary sentence.
1450
 * more text ...
1451
 * ...
1452
 * @@param my_parameter description of my_parameter
1453
 * @@return return value description
1454
 */
1455
int myfunc(int my_parameter)
1456
...
1457
@end example
1458

    
1459
fprintf and printf are forbidden in libavformat and libavcodec,
1460
please use av_log() instead.
1461

    
1462
@section Development Policy
1463

    
1464
@enumerate
1465
@item
1466
   You must not commit code which breaks FFmpeg! (Meaning unfinished but
1467
   enabled code which breaks compilation or compiles but does not work or
1468
   breaks the regression tests)
1469
   You can commit unfinished stuff (for testing etc), but it must be disabled
1470
   (#ifdef etc) by default so it does not interfere with other developers'
1471
   work.
1472
@item
1473
   You don't have to over-test things. If it works for you, and you think it
1474
   should work for others, then commit. If your code has problems
1475
   (portability, triggers compiler bugs, unusual environment etc) they will be
1476
   reported and eventually fixed.
1477
@item
1478
   Do not commit unrelated changes together, split them into self-contained
1479
   pieces.
1480
@item
1481
   Do not change behavior of the program (renaming options etc) without
1482
   first discussing it on the ffmpeg-devel mailing list. Do not remove
1483
   functionality from the code. Just improve!
1484

    
1485
   Note: Redundant code can be removed.
1486
@item
1487
   Do not commit changes to the build system (Makefiles, configure script)
1488
   which change behavior, defaults etc, without asking first. The same
1489
   applies to compiler warning fixes, trivial looking fixes and to code
1490
   maintained by other developers. We usually have a reason for doing things
1491
   the way we do. Send your changes as patches to the ffmpeg-devel mailing
1492
   list, and if the code maintainers say OK, you may commit. This does not
1493
   apply to files you wrote and/or maintain.
1494
@item
1495
   We refuse source indentation and other cosmetic changes if they are mixed
1496
   with functional changes, such commits will be rejected and removed. Every
1497
   developer has his own indentation style, you should not change it. Of course
1498
   if you (re)write something, you can use your own style, even though we would
1499
   prefer if the indentation throughout FFmpeg was consistent (Many projects
1500
   force a given indentation style - we don't.). If you really need to make
1501
   indentation changes (try to avoid this), separate them strictly from real
1502
   changes.
1503

    
1504
   NOTE: If you had to put if()@{ .. @} over a large (> 5 lines) chunk of code,
1505
   then either do NOT change the indentation of the inner part within (don't
1506
   move it to the right)! or do so in a separate commit
1507
@item
1508
   Always fill out the commit log message. Describe in a few lines what you
1509
   changed and why. You can refer to mailing list postings if you fix a
1510
   particular bug. Comments such as "fixed!" or "Changed it." are unacceptable.
1511
@item
1512
   If you apply a patch by someone else, include the name and email address in
1513
   the log message. Since the ffmpeg-cvslog mailing list is publicly
1514
   archived you should add some SPAM protection to the email address. Send an
1515
   answer to ffmpeg-devel (or wherever you got the patch from) saying that
1516
   you applied the patch.
1517
@item
1518
    Do NOT commit to code actively maintained by others without permission.
1519
    Send a patch to ffmpeg-devel instead. If noone answers within a reasonable
1520
    timeframe (12h for build failures and security fixes, 3 days small changes,
1521
    1 week for big patches) then commit your patch if you think it's OK.
1522
    Also note, the maintainer can simply ask for more time to review!
1523
@item
1524
    Subscribe to the ffmpeg-cvslog mailing list. The diffs of all commits
1525
    are sent there and reviewed by all the other developers. Bugs and possible
1526
    improvements or general questions regarding commits are discussed there. We
1527
    expect you to react if problems with your code are uncovered.
1528
@item
1529
    Update the documentation if you change behavior or add features. If you are
1530
    unsure how best to do this, send a patch to ffmpeg-devel, the documentation
1531
    maintainer(s) will review and commit your stuff.
1532
@item
1533
    Never write to unallocated memory, never write over the end of arrays,
1534
    always check values read from some untrusted source before using them
1535
    as array index or other risky things.
1536
@item
1537
    Remember to check if you need to bump versions for the specific libav
1538
    parts (libavutil, libavcodec, libavformat) you are changing. You need
1539
    to change the version integer and the version string.
1540
    Incrementing the first component means no backward compatibility to
1541
    previous versions (e.g. removal of a function from the public API).
1542
    Incrementing the second component means backward compatible change
1543
    (e.g. addition of a function to the public API).
1544
    Incrementing the third component means a noteworthy binary compatible
1545
    change (e.g. encoder bug fix that matters for the decoder).
1546
@item
1547
    If you add a new codec, remember to update the changelog, add it to
1548
    the supported codecs table in the documentation and bump the second
1549
    component of the @file{libavcodec} version number appropriately. If
1550
    it has a fourcc, add it to @file{libavformat/avienc.c}, even if it
1551
    is only a decoder.
1552
@end enumerate
1553

    
1554
We think our rules are not too hard. If you have comments, contact us.
1555

    
1556
Note, these rules are mostly borrowed from the MPlayer project.
1557

    
1558
@section Submitting patches
1559

    
1560
First, (@pxref{Coding Rules}) above if you didn't yet.
1561

    
1562
When you submit your patch, try to send a unified diff (diff '-up'
1563
option). I cannot read other diffs :-)
1564

    
1565
Also please do not submit patches which contain several unrelated changes.
1566
Split them into individual self-contained patches; this makes reviewing
1567
them much easier.
1568

    
1569
Run the regression tests before submitting a patch so that you can
1570
verify that there are no big problems.
1571

    
1572
Patches should be posted as base64 encoded attachments (or any other
1573
encoding which ensures that the patch won't be trashed during
1574
transmission) to the ffmpeg-devel mailing list, see
1575
@url{http://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel}
1576

    
1577
It also helps quite a bit if you tell us what the patch does (for example
1578
'replaces lrint by lrintf'), and why (for example '*BSD isn't C99 compliant
1579
and has no lrint()')
1580

    
1581
We reply to all submitted patches and either apply or reject with some
1582
explanation why, but sometimes we are quite busy so it can take a week or two.
1583

    
1584
@section Regression tests
1585

    
1586
Before submitting a patch (or committing to the repository), you should at least
1587
test that you did not break anything.
1588

    
1589
The regression tests build a synthetic video stream and a synthetic
1590
audio stream. These are then encoded and decoded with all codecs or
1591
formats. The CRC (or MD5) of each generated file is recorded in a
1592
result file. A 'diff' is launched to compare the reference results and
1593
the result file.
1594

    
1595
The regression tests then go on to test the FFserver code with a
1596
limited set of streams. It is important that this step runs correctly
1597
as well.
1598

    
1599
Run 'make test' to test all the codecs and formats.
1600

    
1601
Run 'make fulltest' to test all the codecs, formats and FFserver.
1602

    
1603
[Of course, some patches may change the results of the regression tests. In
1604
this case, the reference results of the regression tests shall be modified
1605
accordingly].
1606

    
1607
@bye