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\input texinfo @c -*- texinfo -*-
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@settitle FFmpeg Documentation
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@titlepage
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@sp 7
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@center @titlefont{FFmpeg Documentation}
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@sp 3
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@end titlepage
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@chapter Introduction
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FFmpeg is a very fast video and audio converter. It can also grab from
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a live audio/video source.
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The command line interface is designed to be intuitive, in the sense
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that FFmpeg tries to figure out all parameters that can possibly be
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derived automatically. You usually only have to specify the target
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bitrate you want.
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FFmpeg can also convert from any sample rate to any other, and resize
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video on the fly with a high quality polyphase filter.
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@chapter Quick Start
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@c man begin EXAMPLES
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@section Video and Audio grabbing
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FFmpeg can grab video and audio from devices given that you specify the input
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format and device.
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@example
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ffmpeg -f audio_device -i /dev/dsp -f video4linux2 -i /dev/video0 /tmp/out.mpg
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@end example
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Note that you must activate the right video source and channel before
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launching FFmpeg with any TV viewer such as xawtv
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(@url{http://bytesex.org/xawtv/}) by Gerd Knorr. You also
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have to set the audio recording levels correctly with a
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standard mixer.
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@section X11 grabbing
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FFmpeg can grab the X11 display.
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@example
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ffmpeg -f x11grab -s cif -i :0.0 /tmp/out.mpg
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@end example
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0.0 is display.screen number of your X11 server, same as
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the DISPLAY environment variable.
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@example
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ffmpeg -f x11grab -s cif -i :0.0+10,20 /tmp/out.mpg
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@end example
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0.0 is display.screen number of your X11 server, same as the DISPLAY environment
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variable. 10 is the x-offset and 20 the y-offset for the grabbing.
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@section Video and Audio file format conversion
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* FFmpeg can use any supported file format and protocol as input:
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Examples:
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* You can use YUV files as input:
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@example
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ffmpeg -i /tmp/test%d.Y /tmp/out.mpg
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@end example
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It will use the files:
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@example
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/tmp/test0.Y, /tmp/test0.U, /tmp/test0.V,
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/tmp/test1.Y, /tmp/test1.U, /tmp/test1.V, etc...
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@end example
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The Y files use twice the resolution of the U and V files. They are
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raw files, without header. They can be generated by all decent video
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decoders. You must specify the size of the image with the @option{-s} option
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if FFmpeg cannot guess it.
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* You can input from a raw YUV420P file:
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@example
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ffmpeg -i /tmp/test.yuv /tmp/out.avi
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@end example
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test.yuv is a file containing raw YUV planar data. Each frame is composed
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of the Y plane followed by the U and V planes at half vertical and
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horizontal resolution.
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* You can output to a raw YUV420P file:
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@example
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ffmpeg -i mydivx.avi hugefile.yuv
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@end example
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* You can set several input files and output files:
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@example
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ffmpeg -i /tmp/a.wav -s 640x480 -i /tmp/a.yuv /tmp/a.mpg
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@end example
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Converts the audio file a.wav and the raw YUV video file a.yuv
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to MPEG file a.mpg.
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* You can also do audio and video conversions at the same time:
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@example
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ffmpeg -i /tmp/a.wav -ar 22050 /tmp/a.mp2
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@end example
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Converts a.wav to MPEG audio at 22050Hz sample rate.
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* You can encode to several formats at the same time and define a
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mapping from input stream to output streams:
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@example
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ffmpeg -i /tmp/a.wav -ab 64k /tmp/a.mp2 -ab 128k /tmp/b.mp2 -map 0:0 -map 0:0
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@end example
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Converts a.wav to a.mp2 at 64 kbits and to b.mp2 at 128 kbits. '-map
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file:index' specifies which input stream is used for each output
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stream, in the order of the definition of output streams.
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* You can transcode decrypted VOBs
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@example
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ffmpeg -i snatch_1.vob -f avi -vcodec mpeg4 -b 800k -g 300 -bf 2 -acodec mp3 -ab 128k snatch.avi
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@end example
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This is a typical DVD ripping example; the input is a VOB file, the
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output an AVI file with MPEG-4 video and MP3 audio. Note that in this
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command we use B-frames so the MPEG-4 stream is DivX5 compatible, and
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GOP size is 300 which means one intra frame every 10 seconds for 29.97fps
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input video. Furthermore, the audio stream is MP3-encoded so you need
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to enable LAME support by passing @code{--enable-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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As a general rule, options are applied to the next specified
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file. Therefore, order is important, and you can have the same
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option on the command line multiple times. Each occurrence is
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then applied to the next input or output file.
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* To set the video bitrate of the output file to 64kbit/s:
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@example
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ffmpeg -i input.avi -b 64k output.avi
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@end example
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* To force the frame rate of the input and output file to 24 fps:
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@example
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ffmpeg -r 24 -i input.avi output.avi
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@end example
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* To force the frame rate of the output file to 24 fps:
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@example
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ffmpeg -i input.avi -r 24 output.avi
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@end example
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* To force the frame rate of input file to 1 fps and the output file to 24 fps:
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@example
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ffmpeg -r 1 -i input.avi -r 24 output.avi
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@end example
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The format option may be needed for raw input files.
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By default, FFmpeg tries to convert as losslessly as possible: It
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uses the same audio and video parameters for the outputs as the one
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specified for the inputs.
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@c man end
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@c man begin OPTIONS
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@section Main options
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@table @option
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@item -L
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Show license.
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@item -h
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Show help.
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@item -version
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Show version.
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@item -formats
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Show available formats, codecs, protocols, ...
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@item -f fmt
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Force format.
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@item -i filename
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input filename
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@item -y
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Overwrite output files.
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@item -t duration
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Set the recording time in seconds.
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@code{hh:mm:ss[.xxx]} syntax is also supported.
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@item -fs limit_size
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Set the file size limit.
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@item -ss position
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Seek to given time position in seconds.
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@code{hh:mm:ss[.xxx]} syntax is also supported.
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@item -itsoffset offset
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Set the input time offset in seconds.
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@code{[-]hh:mm:ss[.xxx]} syntax is also supported.
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This option affects all the input files that follow it.
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The offset is added to the timestamps of the input files.
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Specifying a positive offset means that the corresponding
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streams are delayed by 'offset' seconds.
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@item -title string
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Set the title.
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@item -timestamp time
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Set the timestamp.
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@item -author string
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Set the author.
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@item -copyright string
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Set the copyright.
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@item -comment string
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Set the comment.
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@item -album string
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Set the album.
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@item -track number
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Set the track.
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@item -year number
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Set the year.
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@item -v verbose
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Control amount of logging.
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@item -target type
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Specify target file type ("vcd", "svcd", "dvd", "dv", "dv50", "pal-vcd",
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"ntsc-svcd", ... ). All the format options (bitrate, codecs,
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buffer sizes) are then set automatically. You can just type:
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@example
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ffmpeg -i myfile.avi -target vcd /tmp/vcd.mpg
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@end example
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Nevertheless you can specify additional options as long as you know
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they do not conflict with the standard, as in:
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@example
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ffmpeg -i myfile.avi -target vcd -bf 2 /tmp/vcd.mpg
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@end example
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@item -dframes number
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Set the number of data frames to record.
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@item -scodec codec
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Force subtitle codec ('copy' to copy stream).
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@item -newsubtitle
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Add a new subtitle stream to the current output stream.
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@item -slang code
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Set the ISO 639 language code (3 letters) of the current subtitle stream.
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@end table
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@section Video Options
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@table @option
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@item -b bitrate
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Set the video bitrate in bit/s (default = 200 kb/s).
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@item -vframes number
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Set the number of video frames to record.
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@item -r fps
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Set frame rate (Hz value, fraction or abbreviation), (default = 25).
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@item -s size
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Set frame size. The format is @samp{wxh} (ffserver default = 160x128, ffmpeg default = same as source).
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The following abbreviations are recognized:
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@table @samp
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@item sqcif
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128x96
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@item qcif
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176x144
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@item cif
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352x288
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@item 4cif
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704x576
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@item qqvga
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160x120
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@item qvga
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320x240
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@item vga
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640x480
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@item svga
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800x600
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@item xga
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1024x768
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@item uxga
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1600x1200
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@item qxga
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2048x1536
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@item sxga
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1280x1024
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@item qsxga
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2560x2048
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@item hsxga
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5120x4096
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@item wvga
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852x480
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@item wxga
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1366x768
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@item wsxga
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1600x1024
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@item wuxga
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1920x1200
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@item woxga
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2560x1600
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@item wqsxga
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3200x2048
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@item wquxga
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3840x2400
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@item whsxga
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6400x4096
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@item whuxga
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7680x4800
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@item cga
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320x200
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@item ega
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640x350
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@item hd480
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852x480
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@item hd720
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1280x720
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@item hd1080
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1920x1080
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@end table
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@item -aspect aspect
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Set aspect ratio (4:3, 16:9 or 1.3333, 1.7777).
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@item -croptop size
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Set top crop band size (in pixels).
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@item -cropbottom size
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Set bottom crop band size (in pixels).
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@item -cropleft size
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Set left crop band size (in pixels).
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@item -cropright size
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Set right crop band size (in pixels).
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@item -padtop size
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Set top pad band size (in pixels).
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@item -padbottom size
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Set bottom pad band size (in pixels).
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@item -padleft size
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Set left pad band size (in pixels).
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@item -padright size
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Set right pad band size (in pixels).
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@item -padcolor (hex color)
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Set color of padded bands. The value for padcolor is expressed
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as a six digit hexadecimal number where the first two digits
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represent red, the middle two digits green and last two digits
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blue (default = 000000 (black)).
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@item -vn
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Disable video recording.
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@item -bt tolerance
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Set video bitrate tolerance (in bit/s).
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@item -maxrate bitrate
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Set max video bitrate tolerance (in bit/s).
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@item -minrate bitrate
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Set min video bitrate tolerance (in bit/s).
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@item -bufsize size
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Set rate control buffer size (in bits).
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@item -vcodec codec
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Force video codec to @var{codec}. Use the @code{copy} special value to
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tell that the raw codec data must be copied as is.
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@item -sameq
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Use same video quality as source (implies VBR).
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@item -pass n
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Select the pass number (1 or 2). It is useful to do two pass
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encoding. The statistics of the video are recorded in the first
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pass and the video is generated at the exact requested bitrate
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in the second pass.
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@item -passlogfile file
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Set two pass logfile name to @var{file}.
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@item -newvideo
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Add a new video stream to the current output stream.
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@end table
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@section Advanced Video Options
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@table @option
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@item -pix_fmt format
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Set pixel format.
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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 bit/s (default = 64k).
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@item -ac channels
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Set the number of audio channels (default = 1).
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@item -an
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Disable audio recording.
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@item -acodec codec
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Force audio codec to @var{codec}. Use the @code{copy} special value to
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specify that the raw codec data must be copied as is.
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@item -newaudio
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Add a new audio track to the output file. If you want to specify parameters,
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do so before @code{-newaudio} (@code{-acodec}, @code{-ab}, etc..).
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Mapping will be done automatically, if the number of output streams is equal to
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the number of input streams, else it will pick the first one that matches. You
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can override the mapping using @code{-map} as usual.
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Example:
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@example
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ffmpeg -i file.mpg -vcodec copy -acodec ac3 -ab 384k test.mpg -acodec mp2 -ab 192k -newaudio
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@end example
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@item -alang code
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Set the ISO 639 language code (3 letters) of the current audio stream.
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@end table
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@section Advanced Audio options:
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@table @option
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@item -atag fourcc/tag
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Force audio tag/fourcc.
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@item -absf bitstream filter
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Bitstream filters available are "dump_extra", "remove_extra", "noise", "mp3comp", "mp3decomp".
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@end table
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@section Subtitle options:
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@table @option
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@item -scodec codec
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Force subtitle codec ('copy' to copy stream).
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@item -newsubtitle
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Add a new subtitle stream to the current output stream.
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@item -slang code
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Set the ISO 639 language code (3 letters) of the current subtitle stream.
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@end table
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@section Audio/Video grab options
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@table @option
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@item -vc channel
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Set video grab channel (DV1394 only).
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@item -tvstd standard
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Set television standard (NTSC, PAL (SECAM)).
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@item -isync
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Synchronize read on input.
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@end table
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@section Advanced options
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@table @option
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@item -map input stream id[:input stream id]
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Set stream mapping from input streams to output streams.
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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
678
Add timings for benchmarking.
679
@item -dump
680
Dump each input packet.
681
@item -hex
682
When dumping packets, also dump the payload.
683
@item -bitexact
684
Only use bit exact algorithms (for codec testing).
685
@item -ps size
686
Set packet size in bits.
687
@item -re
688
Read input at native frame rate. Mainly used to simulate a grab device.
689
@item -loop_input
690
Loop over the input stream. Currently it works only for image
691
streams. This option is used for automatic FFserver testing.
692
@item -loop_output number_of_times
693
Repeatedly loop output for formats that support looping such as animated GIF
694
(0 will loop the output infinitely).
695
@item -threads count
696
Thread count.
697
@item -vsync parameter
698
Video sync method. Video will be stretched/squeezed to match the timestamps,
699
it is done by duplicating and dropping frames. With -map you can select from
700
which stream the timestamps should be taken. You can leave either video or
701
audio unchanged and sync the remaining stream(s) to the unchanged one.
702
@item -async samples_per_second
703
Audio sync method. "Stretches/squeezes" the audio stream to match the timestamps,
704
the parameter is the maximum samples per second by which the audio is changed.
705
-async 1 is a special case where only the start of the audio stream is corrected
706
without any later correction.
707
@end table
708

    
709
@node FFmpeg formula evaluator
710
@section FFmpeg formula evaluator
711

    
712
When evaluating a rate control string, FFmpeg uses an internal formula
713
evaluator.
714

    
715
The following binary operators are available: @code{+}, @code{-},
716
@code{*}, @code{/}, @code{^}.
717

    
718
The following unary operators are available: @code{+}, @code{-},
719
@code{(...)}.
720

    
721
The following functions are available:
722
@table @var
723
@item sinh(x)
724
@item cosh(x)
725
@item tanh(x)
726
@item sin(x)
727
@item cos(x)
728
@item tan(x)
729
@item exp(x)
730
@item log(x)
731
@item squish(x)
732
@item gauss(x)
733
@item abs(x)
734
@item max(x, y)
735
@item min(x, y)
736
@item gt(x, y)
737
@item lt(x, y)
738
@item eq(x, y)
739
@item bits2qp(bits)
740
@item qp2bits(qp)
741
@end table
742

    
743
The following constants are available:
744
@table @var
745
@item PI
746
@item E
747
@item iTex
748
@item pTex
749
@item tex
750
@item mv
751
@item fCode
752
@item iCount
753
@item mcVar
754
@item var
755
@item isI
756
@item isP
757
@item isB
758
@item avgQP
759
@item qComp
760
@item avgIITex
761
@item avgPITex
762
@item avgPPTex
763
@item avgBPTex
764
@item avgTex
765
@end table
766

    
767
@c man end
768

    
769
@ignore
770

    
771
@setfilename ffmpeg
772
@settitle FFmpeg video converter
773

    
774
@c man begin SEEALSO
775
ffserver(1), ffplay(1) and the HTML documentation of @file{ffmpeg}.
776
@c man end
777

    
778
@c man begin AUTHOR
779
Fabrice Bellard
780
@c man end
781

    
782
@end ignore
783

    
784
@section Protocols
785

    
786
The filename can be @file{-} to read from standard input or to write
787
to standard output.
788

    
789
FFmpeg also handles many protocols specified with an URL syntax.
790

    
791
Use 'ffmpeg -formats' to see a list of the supported protocols.
792

    
793
The protocol @code{http:} is currently used only to communicate with
794
FFserver (see the FFserver documentation). When FFmpeg will be a
795
video player it will also be used for streaming :-)
796

    
797
@chapter Tips
798

    
799
@itemize
800
@item For streaming at very low bitrate application, use a low frame rate
801
and a small GOP size. This is especially true for RealVideo where
802
the Linux player does not seem to be very fast, so it can miss
803
frames. An example is:
804

    
805
@example
806
ffmpeg -g 3 -r 3 -t 10 -b 50k -s qcif -f rv10 /tmp/b.rm
807
@end example
808

    
809
@item  The parameter 'q' which is displayed while encoding is the current
810
quantizer. The value 1 indicates that a very good quality could
811
be achieved. The value 31 indicates the worst quality. If q=31 appears
812
too often, it means that the encoder cannot compress enough to meet
813
your bitrate. You must either increase the bitrate, decrease the
814
frame rate or decrease the frame size.
815

    
816
@item If your computer is not fast enough, you can speed up the
817
compression at the expense of the compression ratio. You can use
818
'-me zero' to speed up motion estimation, and '-intra' to disable
819
motion estimation completely (you have only I-frames, which means it
820
is about as good as JPEG compression).
821

    
822
@item To have very low audio bitrates, reduce the sampling frequency
823
(down to 22050 kHz for MPEG audio, 22050 or 11025 for AC3).
824

    
825
@item To have a constant quality (but a variable bitrate), use the option
826
'-qscale n' when 'n' is between 1 (excellent quality) and 31 (worst
827
quality).
828

    
829
@item When converting video files, you can use the '-sameq' option which
830
uses the same quality factor in the encoder as in the decoder.
831
It allows almost lossless encoding.
832

    
833
@end itemize
834

    
835

    
836
@chapter external libraries
837

    
838
FFmpeg can be hooked up with a number of external libraries to add support
839
for more formats. None of them are used by default, their use has to be
840
explicitly requested by passing the appropriate flags to @file{./configure}.
841

    
842
@section AMR
843

    
844
AMR comes in two different flavors, WB and NB. FFmpeg can make use of the
845
AMR WB (floating-point mode) and the AMR NB (both floating-point and
846
fixed-point mode) reference decoders and encoders.
847

    
848
@itemize
849

    
850
@item For AMR WB floating-point and AMR NB floating point support, go to
851
@url{http://www.penguin.cz/~utx/amr} and follow the instructions for building
852
the libraries. Pass @code{--enable-amr-nb} and/or @code{--enable-amr-wb} to
853
configure to enable the libraries.
854

    
855
@item For AMR NB fixed-point download TS26.073 REL-6 V6.0.0 from
856
@url{http://www.3gpp.org/ftp/Specs/archive/26_series/26.073/26073-600.zip}
857
and extract the source to the directory @file{libavcodec/amr}.
858
You must also add @code{-DMMS_IO} to @code{CFLAGS} in
859
@file{libavcodec/amr/makefile}, i.e.
860
``@code{CFLAGS = -Wall -pedantic-errors -I. $(CFLAGS_$(MODE)) -D$(VAD) -DMMS_IO}''.
861
Pass @code{--enable-amr-nb-fixed} to configure to enable it.
862

    
863
@end itemize
864

    
865

    
866
@chapter Supported File Formats and Codecs
867

    
868
You can use the @code{-formats} option to have an exhaustive list.
869

    
870
@section File Formats
871

    
872
FFmpeg supports the following file formats through the @code{libavformat}
873
library:
874

    
875
@multitable @columnfractions .4 .1 .1 .4
876
@item Supported File Format @tab Encoding @tab Decoding @tab Comments
877
@item MPEG audio @tab X @tab X
878
@item MPEG-1 systems @tab X  @tab  X
879
@tab muxed audio and video
880
@item MPEG-2 PS @tab X  @tab  X
881
@tab also known as @code{VOB} file
882
@item MPEG-2 TS @tab    @tab  X
883
@tab also known as DVB Transport Stream
884
@item ASF@tab X @tab X
885
@item AVI@tab X @tab X
886
@item WAV@tab X @tab X
887
@item Macromedia Flash@tab X @tab X
888
@tab Only embedded audio is decoded.
889
@item FLV              @tab  X @tab X
890
@tab Macromedia Flash video files
891
@item Real Audio and Video @tab X @tab X
892
@item Raw AC3 @tab X  @tab  X
893
@item Raw MJPEG @tab X  @tab  X
894
@item Raw MPEG video @tab X  @tab  X
895
@item Raw PCM8/16 bits, mulaw/Alaw@tab X  @tab  X
896
@item Raw CRI ADX audio @tab X  @tab  X
897
@item Raw Shorten audio @tab    @tab  X
898
@item SUN AU format @tab X  @tab  X
899
@item NUT @tab X @tab X @tab NUT Open Container Format
900
@item QuickTime        @tab X @tab  X
901
@item MPEG-4           @tab X @tab  X
902
@tab MPEG-4 is a variant of QuickTime.
903
@item Raw MPEG4 video  @tab  X @tab  X
904
@item DV               @tab  X @tab  X
905
@item 4xm              @tab    @tab X
906
@tab 4X Technologies format, used in some games.
907
@item Playstation STR  @tab    @tab X
908
@item Id RoQ           @tab    @tab X
909
@tab Used in Quake III, Jedi Knight 2, other computer games.
910
@item Interplay MVE    @tab    @tab X
911
@tab Format used in various Interplay computer games.
912
@item WC3 Movie        @tab    @tab X
913
@tab Multimedia format used in Origin's Wing Commander III computer game.
914
@item Sega FILM/CPK    @tab    @tab X
915
@tab Used in many Sega Saturn console games.
916
@item Westwood Studios VQA/AUD  @tab    @tab X
917
@tab Multimedia formats used in Westwood Studios games.
918
@item Id Cinematic (.cin) @tab    @tab X
919
@tab Used in Quake II.
920
@item FLIC format      @tab    @tab X
921
@tab .fli/.flc files
922
@item Sierra VMD       @tab    @tab X
923
@tab Used in Sierra CD-ROM games.
924
@item Sierra Online    @tab    @tab X
925
@tab .sol files used in Sierra Online games.
926
@item Matroska         @tab    @tab X
927
@item Electronic Arts Multimedia    @tab    @tab X
928
@tab Used in various EA games; files have extensions like WVE and UV2.
929
@item Nullsoft Video (NSV) format @tab    @tab X
930
@item ADTS AAC audio @tab X @tab X
931
@item Creative VOC @tab X @tab X @tab Created for the Sound Blaster Pro.
932
@item American Laser Games MM  @tab    @tab X
933
@tab Multimedia format used in games like Mad Dog McCree
934
@item AVS @tab    @tab X
935
@tab Multimedia format used by the Creature Shock game.
936
@item Smacker @tab    @tab X
937
@tab Multimedia format used by many games.
938
@item GXF @tab  X @tab X
939
@tab General eXchange Format SMPTE 360M, used by Thomson Grass Valley playout servers.
940
@item CIN @tab    @tab X
941
@tab Multimedia format used by Delphine Software games.
942
@item MXF @tab    @tab X
943
@tab Material eXchange Format SMPTE 377M, used by D-Cinema, broadcast industry.
944
@item SEQ @tab    @tab X
945
@tab Tiertex .seq files used in the DOS CDROM version of the game Flashback.
946
@item DXA @tab    @tab X
947
@tab This format is used in non-Windows version of Feeble Files game and
948
different game cutscenes repacked for use with ScummVM.
949
@item THP @tab    @tab X
950
@tab Used on the Nintendo GameCube.
951
@item C93 @tab    @tab X
952
@tab Used in the game Cyberia from Interplay.
953
@item Bethsoft VID @tab    @tab X
954
@tab Used in some games from Bethesda Softworks.
955
@item CRYO APC @tab    @tab X
956
@tab Audio format used in some games by CRYO Interactive Entertainment.
957
@end multitable
958

    
959
@code{X} means that encoding (resp. decoding) is supported.
960

    
961
@section Image Formats
962

    
963
FFmpeg can read and write images for each frame of a video sequence. The
964
following image formats are supported:
965

    
966
@multitable @columnfractions .4 .1 .1 .4
967
@item Supported Image Format @tab Encoding @tab Decoding @tab Comments
968
@item PGM, PPM     @tab X @tab X
969
@item PAM          @tab X @tab X @tab PAM is a PNM extension with alpha support.
970
@item PGMYUV       @tab X @tab X @tab PGM with U and V components in YUV 4:2:0
971
@item JPEG         @tab X @tab X @tab Progressive JPEG is not supported.
972
@item .Y.U.V       @tab X @tab X @tab one raw file per component
973
@item animated GIF @tab X @tab X @tab Only uncompressed GIFs are generated.
974
@item PNG          @tab X @tab X @tab 2 bit and 4 bit/pixel not supported yet.
975
@item Targa        @tab   @tab X @tab Targa (.TGA) image format.
976
@item TIFF         @tab X @tab X @tab YUV, JPEG and some extension is not supported yet.
977
@item SGI          @tab X @tab X @tab SGI RGB image format
978
@end multitable
979

    
980
@code{X} means that encoding (resp. decoding) is supported.
981

    
982
@section Video Codecs
983

    
984
@multitable @columnfractions .4 .1 .1 .4
985
@item Supported Codec @tab Encoding @tab Decoding @tab Comments
986
@item MPEG-1 video           @tab  X  @tab  X
987
@item MPEG-2 video           @tab  X  @tab  X
988
@item MPEG-4                 @tab  X  @tab  X
989
@item MSMPEG4 V1             @tab  X  @tab  X
990
@item MSMPEG4 V2             @tab  X  @tab  X
991
@item MSMPEG4 V3             @tab  X  @tab  X
992
@item WMV7                   @tab  X  @tab  X
993
@item WMV8                   @tab  X  @tab  X @tab not completely working
994
@item WMV9                   @tab     @tab  X @tab not completely working
995
@item VC1                    @tab     @tab  X
996
@item H.261                  @tab  X  @tab  X
997
@item H.263(+)               @tab  X  @tab  X @tab also known as RealVideo 1.0
998
@item H.264                  @tab     @tab  X
999
@item RealVideo 1.0          @tab  X  @tab  X
1000
@item RealVideo 2.0          @tab  X  @tab  X
1001
@item MJPEG                  @tab  X  @tab  X
1002
@item lossless MJPEG         @tab  X  @tab  X
1003
@item JPEG-LS                @tab  X  @tab  X @tab fourcc: MJLS, lossless and near-lossless is supported
1004
@item Apple MJPEG-B          @tab     @tab  X
1005
@item Sunplus MJPEG          @tab     @tab  X @tab fourcc: SP5X
1006
@item DV                     @tab  X  @tab  X
1007
@item HuffYUV                @tab  X  @tab  X
1008
@item FFmpeg Video 1         @tab  X  @tab  X @tab experimental lossless codec (fourcc: FFV1)
1009
@item FFmpeg Snow            @tab  X  @tab  X @tab experimental wavelet codec (fourcc: SNOW)
1010
@item Asus v1                @tab  X  @tab  X @tab fourcc: ASV1
1011
@item Asus v2                @tab  X  @tab  X @tab fourcc: ASV2
1012
@item Creative YUV           @tab     @tab  X @tab fourcc: CYUV
1013
@item Sorenson Video 1       @tab  X  @tab  X @tab fourcc: SVQ1
1014
@item Sorenson Video 3       @tab     @tab  X @tab fourcc: SVQ3
1015
@item On2 VP3                @tab     @tab  X @tab still experimental
1016
@item On2 VP5                @tab     @tab  X @tab fourcc: VP50
1017
@item On2 VP6                @tab     @tab  X @tab fourcc: VP60,VP61,VP62
1018
@item Theora                 @tab  X  @tab  X @tab still experimental
1019
@item Intel Indeo 3          @tab     @tab  X
1020
@item FLV                    @tab  X  @tab  X @tab Sorenson H.263 used in Flash
1021
@item Flash Screen Video     @tab  X  @tab  X @tab fourcc: FSV1
1022
@item ATI VCR1               @tab     @tab  X @tab fourcc: VCR1
1023
@item ATI VCR2               @tab     @tab  X @tab fourcc: VCR2
1024
@item Cirrus Logic AccuPak   @tab     @tab  X @tab fourcc: CLJR
1025
@item 4X Video               @tab     @tab  X @tab Used in certain computer games.
1026
@item Sony Playstation MDEC  @tab     @tab  X
1027
@item Id RoQ                 @tab     @tab  X @tab Used in Quake III, Jedi Knight 2, other computer games.
1028
@item Xan/WC3                @tab     @tab  X @tab Used in Wing Commander III .MVE files.
1029
@item Interplay Video        @tab     @tab  X @tab Used in Interplay .MVE files.
1030
@item Apple Animation        @tab     @tab  X @tab fourcc: 'rle '
1031
@item Apple Graphics         @tab     @tab  X @tab fourcc: 'smc '
1032
@item Apple Video            @tab     @tab  X @tab fourcc: rpza
1033
@item Apple QuickDraw        @tab     @tab  X @tab fourcc: qdrw
1034
@item Cinepak                @tab     @tab  X
1035
@item Microsoft RLE          @tab     @tab  X
1036
@item Microsoft Video-1      @tab     @tab  X
1037
@item Westwood VQA           @tab     @tab  X
1038
@item Id Cinematic Video     @tab     @tab  X @tab Used in Quake II.
1039
@item Planar RGB             @tab     @tab  X @tab fourcc: 8BPS
1040
@item FLIC video             @tab     @tab  X
1041
@item Duck TrueMotion v1     @tab     @tab  X @tab fourcc: DUCK
1042
@item Duck TrueMotion v2     @tab     @tab  X @tab fourcc: TM20
1043
@item VMD Video              @tab     @tab  X @tab Used in Sierra VMD files.
1044
@item MSZH                   @tab     @tab  X @tab Part of LCL
1045
@item ZLIB                   @tab  X  @tab  X @tab Part of LCL, encoder experimental
1046
@item TechSmith Camtasia     @tab     @tab  X @tab fourcc: TSCC
1047
@item IBM Ultimotion         @tab     @tab  X @tab fourcc: ULTI
1048
@item Miro VideoXL           @tab     @tab  X @tab fourcc: VIXL
1049
@item QPEG                   @tab     @tab  X @tab fourccs: QPEG, Q1.0, Q1.1
1050
@item LOCO                   @tab     @tab  X @tab
1051
@item Winnov WNV1            @tab     @tab  X @tab
1052
@item Autodesk Animator Studio Codec  @tab     @tab  X @tab fourcc: AASC
1053
@item Fraps FPS1             @tab     @tab  X @tab
1054
@item CamStudio              @tab     @tab  X @tab fourcc: CSCD
1055
@item American Laser Games Video  @tab    @tab X @tab Used in games like Mad Dog McCree
1056
@item ZMBV                   @tab   X @tab  X @tab Encoder works only on PAL8
1057
@item AVS Video              @tab     @tab  X @tab Video encoding used by the Creature Shock game.
1058
@item Smacker Video          @tab     @tab  X @tab Video encoding used in Smacker.
1059
@item RTjpeg                 @tab     @tab  X @tab Video encoding used in NuppelVideo files.
1060
@item KMVC                   @tab     @tab  X @tab Codec used in Worms games.
1061
@item VMware Video           @tab     @tab  X @tab Codec used in videos captured by VMware.
1062
@item Cin Video              @tab     @tab  X @tab Codec used in Delphine Software games.
1063
@item Tiertex Seq Video      @tab     @tab  X @tab Codec used in DOS CDROM FlashBack game.
1064
@item DXA Video              @tab     @tab  X @tab Codec originally used in Feeble Files game.
1065
@item AVID DNxHD             @tab     @tab  X @tab aka SMPTE VC3
1066
@item C93 Video              @tab     @tab  X @tab Codec used in Cyberia game.
1067
@item THP                    @tab     @tab  X @tab Used on the Nintendo GameCube.
1068
@item Bethsoft VID           @tab     @tab  X @tab Used in some games from Bethesda Softworks.
1069
@end multitable
1070

    
1071
@code{X} means that encoding (resp. decoding) is supported.
1072

    
1073
@section Audio Codecs
1074

    
1075
@multitable @columnfractions .4 .1 .1 .1 .7
1076
@item Supported Codec @tab Encoding @tab Decoding @tab Comments
1077
@item MPEG audio layer 2     @tab  IX  @tab  IX
1078
@item MPEG audio layer 1/3   @tab IX   @tab  IX
1079
@tab MP3 encoding is supported through the external library LAME.
1080
@item AC3                    @tab  IX  @tab  IX
1081
@tab liba52 is used internally for decoding.
1082
@item Vorbis                 @tab  X   @tab  X
1083
@item WMA V1/V2              @tab X    @tab X
1084
@item AAC                    @tab X    @tab X
1085
@tab Supported through the external library libfaac/libfaad.
1086
@item Microsoft ADPCM        @tab X    @tab X
1087
@item MS IMA ADPCM           @tab X    @tab X
1088
@item QT IMA ADPCM           @tab      @tab X
1089
@item 4X IMA ADPCM           @tab      @tab X
1090
@item G.726  ADPCM           @tab X    @tab X
1091
@item Duck DK3 IMA ADPCM     @tab      @tab X
1092
@tab Used in some Sega Saturn console games.
1093
@item Duck DK4 IMA ADPCM     @tab      @tab X
1094
@tab Used in some Sega Saturn console games.
1095
@item Westwood Studios IMA ADPCM @tab      @tab X
1096
@tab Used in Westwood Studios games like Command and Conquer.
1097
@item SMJPEG IMA ADPCM       @tab      @tab X
1098
@tab Used in certain Loki game ports.
1099
@item CD-ROM XA ADPCM        @tab      @tab X
1100
@item CRI ADX ADPCM          @tab X    @tab X
1101
@tab Used in Sega Dreamcast games.
1102
@item Electronic Arts ADPCM  @tab      @tab X
1103
@tab Used in various EA titles.
1104
@item Creative ADPCM         @tab      @tab X
1105
@tab 16 -> 4, 8 -> 4, 8 -> 3, 8 -> 2
1106
@item THP ADPCM              @tab      @tab X
1107
@tab Used on the Nintendo GameCube.
1108
@item RA144                  @tab      @tab X
1109
@tab Real 14400 bit/s codec
1110
@item RA288                  @tab      @tab X
1111
@tab Real 28800 bit/s codec
1112
@item RADnet                 @tab X    @tab IX
1113
@tab Real low bitrate AC3 codec, liba52 is used for decoding.
1114
@item AMR-NB                 @tab X    @tab X
1115
@tab Supported through an external library.
1116
@item AMR-WB                 @tab X    @tab X
1117
@tab Supported through an external library.
1118
@item DV audio               @tab      @tab X
1119
@item Id RoQ DPCM            @tab      @tab X
1120
@tab Used in Quake III, Jedi Knight 2, other computer games.
1121
@item Interplay MVE DPCM     @tab      @tab X
1122
@tab Used in various Interplay computer games.
1123
@item Xan DPCM               @tab      @tab X
1124
@tab Used in Origin's Wing Commander IV AVI files.
1125
@item Sierra Online DPCM     @tab      @tab X
1126
@tab Used in Sierra Online game audio files.
1127
@item Apple MACE 3           @tab      @tab X
1128
@item Apple MACE 6           @tab      @tab X
1129
@item FLAC lossless audio    @tab X    @tab X
1130
@item Shorten lossless audio @tab      @tab X
1131
@item Apple lossless audio   @tab      @tab X
1132
@tab QuickTime fourcc 'alac'
1133
@item FFmpeg Sonic           @tab X    @tab X
1134
@tab experimental lossy/lossless codec
1135
@item Qdesign QDM2           @tab      @tab X
1136
@tab there are still some distortions
1137
@item Real COOK              @tab      @tab X
1138
@tab All versions except 5.1 are supported
1139
@item DSP Group TrueSpeech   @tab      @tab X
1140
@item True Audio (TTA)       @tab      @tab X
1141
@item Smacker Audio          @tab      @tab X
1142
@item WavPack Audio          @tab      @tab X
1143
@item Cin Audio              @tab      @tab X
1144
@tab Codec used in Delphine Software games.
1145
@item Intel Music Coder      @tab      @tab X
1146
@item Musepack               @tab      @tab X
1147
@tab Only SV7 is supported
1148
@item DT$ Coherent Audio     @tab      @tab X
1149
@item ATRAC 3                @tab      @tab X
1150
@end multitable
1151

    
1152
@code{X} means that encoding (resp. decoding) is supported.
1153

    
1154
@code{I} means that an integer-only version is available, too (ensures high
1155
performance on systems without hardware floating point support).
1156

    
1157
@chapter Platform Specific information
1158

    
1159
@section BSD
1160

    
1161
BSD make will not build FFmpeg, you need to install and use GNU Make
1162
(@file{gmake}).
1163

    
1164
@section Windows
1165

    
1166
To get help and instructions for using FFmpeg under Windows, check out
1167
the FFmpeg Windows Help Forum at
1168
@url{http://arrozcru.no-ip.org/ffmpeg/}.
1169

    
1170
@subsection Native Windows compilation
1171

    
1172
@itemize
1173
@item Install the current versions of MSYS and MinGW from
1174
@url{http://www.mingw.org/}. You can find detailed installation
1175
instructions in the download section and the FAQ.
1176

    
1177
NOTE: Use at least bash 3.1. Older versions are known to be failing on the
1178
configure script.
1179

    
1180
@item If you want to test the FFplay, also download
1181
the MinGW development library of SDL 1.2.x
1182
(@file{SDL-devel-1.2.x-mingw32.tar.gz}) from
1183
@url{http://www.libsdl.org}. Unpack it in a temporary directory, and
1184
unpack the archive @file{i386-mingw32msvc.tar.gz} in the MinGW tool
1185
directory. Edit the @file{sdl-config} script so that it gives the
1186
correct SDL directory when invoked.
1187

    
1188
@item Extract the current version of FFmpeg.
1189

    
1190
@item Start the MSYS shell (file @file{msys.bat}).
1191

    
1192
@item Change to the FFmpeg directory and follow
1193
 the instructions of how to compile FFmpeg (file
1194
@file{INSTALL}). Usually, launching @file{./configure} and @file{make}
1195
suffices. If you have problems using SDL, verify that
1196
@file{sdl-config} can be launched from the MSYS command line.
1197

    
1198
@item You can install FFmpeg in @file{Program Files/FFmpeg} by typing
1199
@file{make install}. Do not forget to copy @file{SDL.dll} to the place
1200
you launch @file{ffplay} from.
1201

    
1202
@end itemize
1203

    
1204
Notes:
1205
@itemize
1206

    
1207
@item The target @file{make wininstaller} can be used to create a
1208
Nullsoft based Windows installer for FFmpeg and FFplay. @file{SDL.dll}
1209
must be copied to the FFmpeg directory in order to build the
1210
installer.
1211

    
1212
@item By using @code{./configure --enable-shared} when configuring FFmpeg,
1213
you can build @file{avcodec.dll} and @file{avformat.dll}. With
1214
@code{make install} you install the FFmpeg DLLs and the associated
1215
headers in @file{Program Files/FFmpeg}.
1216

    
1217
@item Visual C++ compatibility: If you used @code{./configure --enable-shared}
1218
when configuring FFmpeg, FFmpeg tries to use the Microsoft Visual
1219
C++ @code{lib} tool to build @code{avcodec.lib} and
1220
@code{avformat.lib}. With these libraries you can link your Visual C++
1221
code directly with the FFmpeg DLLs (see below).
1222

    
1223
@end itemize
1224

    
1225
@subsection Visual C++ compatibility
1226

    
1227
FFmpeg will not compile under Visual C++ -- and it has too many
1228
dependencies on the GCC compiler to make a port viable. However,
1229
if you want to use the FFmpeg libraries in your own applications,
1230
you can still compile those applications using Visual C++. An
1231
important restriction to this is that you have to use the
1232
dynamically linked versions of the FFmpeg libraries (i.e. the
1233
DLLs), and you have to make sure that Visual-C++-compatible
1234
import libraries are created during the FFmpeg build process.
1235

    
1236
This description of how to use the FFmpeg libraries with Visual C++ is
1237
based on Visual C++ 2005 Express Edition Beta 2. If you have a different
1238
version, you might have to modify the procedures slightly.
1239

    
1240
Here are the step-by-step instructions for building the FFmpeg libraries
1241
so they can be used with Visual C++:
1242

    
1243
@enumerate
1244

    
1245
@item Install Visual C++ (if you have not done so already).
1246

    
1247
@item Install MinGW and MSYS as described above.
1248

    
1249
@item Add a call to @file{vcvars32.bat} (which sets up the environment
1250
variables for the Visual C++ tools) as the first line of
1251
@file{msys.bat}. The standard location for @file{vcvars32.bat} is
1252
@file{C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat},
1253
and the standard location for @file{msys.bat} is
1254
@file{C:\msys\1.0\msys.bat}. If this corresponds to your setup, add the
1255
following line as the first line of @file{msys.bat}:
1256

    
1257
@code{call "C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat"}
1258

    
1259
@item Start the MSYS shell (file @file{msys.bat}) and type @code{link.exe}.
1260
If you get a help message with the command line options of @code{link.exe},
1261
this means your environment variables are set up correctly, the
1262
Microsoft linker is on the path and will be used by FFmpeg to
1263
create Visual-C++-compatible import libraries.
1264

    
1265
@item Extract the current version of FFmpeg and change to the FFmpeg directory.
1266

    
1267
@item Type the command
1268
@code{./configure --enable-shared --disable-static --enable-memalign-hack}
1269
to configure and, if that did not produce any errors,
1270
type @code{make} to build FFmpeg.
1271

    
1272
@item The subdirectories @file{libavformat}, @file{libavcodec}, and
1273
@file{libavutil} should now contain the files @file{avformat.dll},
1274
@file{avformat.lib}, @file{avcodec.dll}, @file{avcodec.lib},
1275
@file{avutil.dll}, and @file{avutil.lib}, respectively. Copy the three
1276
DLLs to your System32 directory (typically @file{C:\Windows\System32}).
1277

    
1278
@end enumerate
1279

    
1280
And here is how to use these libraries with Visual C++:
1281

    
1282
@enumerate
1283

    
1284
@item Create a new console application ("File / New / Project") and then
1285
select "Win32 Console Application". On the appropriate page of the
1286
Application Wizard, uncheck the "Precompiled headers" option.
1287

    
1288
@item Write the source code for your application, or, for testing, just
1289
copy the code from an existing sample application into the source file
1290
that Visual C++ has already created for you. (Note that your source
1291
filehas to have a @code{.cpp} extension; otherwise, Visual C++ will not
1292
compile the FFmpeg headers correctly because in C mode, it does not
1293
recognize the @code{inline} keyword.)  For example, you can copy
1294
@file{output_example.c} from the FFmpeg distribution (but you will
1295
have to make minor modifications so the code will compile under
1296
C++, see below).
1297

    
1298
@item Open the "Project / Properties" dialog box. In the "Configuration"
1299
combo box, select "All Configurations" so that the changes you make will
1300
affect both debug and release builds. In the tree view on the left hand
1301
side, select "C/C++ / General", then edit the "Additional Include
1302
Directories" setting to contain the complete paths to the
1303
@file{libavformat}, @file{libavcodec}, and @file{libavutil}
1304
subdirectories of your FFmpeg directory. Note that the directories have
1305
to be separated using semicolons. Now select "Linker / General" from the
1306
tree view and edit the "Additional Library Directories" setting to
1307
contain the same three directories.
1308

    
1309
@item Still in the "Project / Properties" dialog box, select "Linker / Input"
1310
from the tree view, then add the files @file{avformat.lib},
1311
@file{avcodec.lib}, and @file{avutil.lib} to the end of the "Additional
1312
Dependencies". Note that the names of the libraries have to be separated
1313
using spaces.
1314

    
1315
@item Now, select "C/C++ / Code Generation" from the tree view. Select
1316
"Debug" in the "Configuration" combo box. Make sure that "Runtime
1317
Library" is set to "Multi-threaded Debug DLL". Then, select "Release" in
1318
the "Configuration" combo box and make sure that "Runtime Library" is
1319
set to "Multi-threaded DLL".
1320

    
1321
@item Click "OK" to close the "Project / Properties" dialog box and build
1322
the application. Hopefully, it should compile and run cleanly. If you
1323
used @file{output_example.c} as your sample application, you will get a
1324
few compiler errors, but they are easy to fix. The first type of error
1325
occurs because Visual C++ does not allow an @code{int} to be converted to
1326
an @code{enum} without a cast. To solve the problem, insert the required
1327
casts (this error occurs once for a @code{CodecID} and once for a
1328
@code{CodecType}).  The second type of error occurs because C++ requires
1329
the return value of @code{malloc} to be cast to the exact type of the
1330
pointer it is being assigned to. Visual C++ will complain that, for
1331
example, @code{(void *)} is being assigned to @code{(uint8_t *)} without
1332
an explicit cast. So insert an explicit cast in these places to silence
1333
the compiler. The third type of error occurs because the @code{snprintf}
1334
library function is called @code{_snprintf} under Visual C++.  So just
1335
add an underscore to fix the problem. With these changes,
1336
@file{output_example.c} should compile under Visual C++, and the
1337
resulting executable should produce valid video files.
1338

    
1339
@end enumerate
1340

    
1341
@subsection Cross compilation for Windows with Linux
1342

    
1343
You must use the MinGW cross compilation tools available at
1344
@url{http://www.mingw.org/}.
1345

    
1346
Then configure FFmpeg with the following options:
1347
@example
1348
./configure --target-os=mingw32 --cross-prefix=i386-mingw32msvc-
1349
@end example
1350
(you can change the cross-prefix according to the prefix chosen for the
1351
MinGW tools).
1352

    
1353
Then you can easily test FFmpeg with Wine
1354
(@url{http://www.winehq.com/}).
1355

    
1356
@subsection Compilation under Cygwin
1357

    
1358
Cygwin works very much like Unix.
1359

    
1360
Just install your Cygwin with all the "Base" packages, plus the
1361
following "Devel" ones:
1362
@example
1363
binutils, gcc-core, make, subversion
1364
@end example
1365

    
1366
Do not install binutils-20060709-1 (they are buggy on shared builds);
1367
use binutils-20050610-1 instead.
1368

    
1369
Then run
1370

    
1371
@example
1372
./configure --enable-static --disable-shared
1373
@end example
1374

    
1375
to make a static build or
1376

    
1377
@example
1378
./configure --enable-shared --disable-static
1379
@end example
1380

    
1381
to build shared libraries.
1382

    
1383
If you want to build FFmpeg with additional libraries, download Cygwin
1384
"Devel" packages for Ogg and Vorbis from any Cygwin packages repository
1385
and/or SDL, xvid, faac, faad2 packages from Cygwin Ports,
1386
(@url{http://cygwinports.dotsrc.org/}).
1387

    
1388
@subsection Crosscompilation for Windows under Cygwin
1389

    
1390
With Cygwin you can create Windows binaries that do not need the cygwin1.dll.
1391

    
1392
Just install your Cygwin as explained before, plus these additional
1393
"Devel" packages:
1394
@example
1395
gcc-mingw-core, mingw-runtime, mingw-zlib
1396
@end example
1397

    
1398
and add some special flags to your configure invocation.
1399

    
1400
For a static build run
1401
@example
1402
./configure --target-os=mingw32 --enable-memalign-hack --enable-static --disable-shared --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
1403
@end example
1404

    
1405
and for a build with shared libraries
1406
@example
1407
./configure --target-os=mingw32 --enable-memalign-hack --enable-shared --disable-static --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
1408
@end example
1409

    
1410
@section BeOS
1411

    
1412
The configure script should guess the configuration itself.
1413
Networking support is currently not finished.
1414
errno issues fixed by Andrew Bachmann.
1415

    
1416
Old stuff:
1417

    
1418
Fran├žois Revol - revol at free dot fr - April 2002
1419

    
1420
The configure script should guess the configuration itself,
1421
however I still did not test building on the net_server version of BeOS.
1422

    
1423
FFserver is broken (needs poll() implementation).
1424

    
1425
There are still issues with errno codes, which are negative in BeOS, and
1426
that FFmpeg negates when returning. This ends up turning errors into
1427
valid results, then crashes.
1428
(To be fixed)
1429

    
1430
@chapter Developers Guide
1431

    
1432
@section API
1433
@itemize @bullet
1434
@item libavcodec is the library containing the codecs (both encoding and
1435
decoding). Look at @file{libavcodec/apiexample.c} to see how to use it.
1436

    
1437
@item libavformat is the library containing the file format handling (mux and
1438
demux code for several formats). Look at @file{ffplay.c} to use it in a
1439
player. See @file{output_example.c} to use it to generate audio or video
1440
streams.
1441

    
1442
@end itemize
1443

    
1444
@section Integrating libavcodec or libavformat in your program
1445

    
1446
You can integrate all the source code of the libraries to link them
1447
statically to avoid any version problem. All you need is to provide a
1448
'config.mak' and a 'config.h' in the parent directory. See the defines
1449
generated by ./configure to understand what is needed.
1450

    
1451
You can use libavcodec or libavformat in your commercial program, but
1452
@emph{any patch you make must be published}. The best way to proceed is
1453
to send your patches to the FFmpeg mailing list.
1454

    
1455
@node Coding Rules
1456
@section Coding Rules
1457

    
1458
FFmpeg is programmed in the ISO C90 language with a few additional
1459
features from ISO C99, namely:
1460
@itemize @bullet
1461
@item
1462
the @samp{inline} keyword;
1463
@item
1464
@samp{//} comments;
1465
@item
1466
designated struct initializers (@samp{struct s x = @{ .i = 17 @};})
1467
@item
1468
compound literals (@samp{x = (struct s) @{ 17, 23 @};})
1469
@end itemize
1470

    
1471
These features are supported by all compilers we care about, so we will not
1472
accept patches to remove their use unless they absolutely do not impair
1473
clarity and performance.
1474

    
1475
All code must compile with GCC 2.95 and GCC 3.3. Currently, FFmpeg also
1476
compiles with several other compilers, such as the Compaq ccc compiler
1477
or Sun Studio 9, and we would like to keep it that way unless it would
1478
be exceedingly involved. To ensure compatibility, please do not use any
1479
additional C99 features or GCC extensions. Especially watch out for:
1480
@itemize @bullet
1481
@item
1482
mixing statements and declarations;
1483
@item
1484
@samp{long long} (use @samp{int64_t} instead);
1485
@item
1486
@samp{__attribute__} not protected by @samp{#ifdef __GNUC__} or similar;
1487
@item
1488
GCC statement expressions (@samp{(x = (@{ int y = 4; y; @})}).
1489
@end itemize
1490

    
1491
Indent size is 4.
1492
The presentation is the one specified by 'indent -i4 -kr -nut'.
1493
The TAB character is forbidden outside of Makefiles as is any
1494
form of trailing whitespace. Commits containing either will be
1495
rejected by the Subversion repository.
1496

    
1497
Main priority in FFmpeg is simplicity and small code size (=less
1498
bugs).
1499

    
1500
Comments: Use the JavaDoc/Doxygen
1501
format (see examples below) so that code documentation
1502
can be generated automatically. All nontrivial functions should have a comment
1503
above them explaining what the function does, even if it is just one sentence.
1504
All structures and their member variables should be documented, too.
1505
@example
1506
/**
1507
 * @@file mpeg.c
1508
 * MPEG codec.
1509
 * @@author ...
1510
 */
1511

    
1512
/**
1513
 * Summary sentence.
1514
 * more text ...
1515
 * ...
1516
 */
1517
typedef struct Foobar@{
1518
    int var1; /**< var1 description */
1519
    int var2; ///< var2 description
1520
    /** var3 description */
1521
    int var3;
1522
@} Foobar;
1523

    
1524
/**
1525
 * Summary sentence.
1526
 * more text ...
1527
 * ...
1528
 * @@param my_parameter description of my_parameter
1529
 * @@return return value description
1530
 */
1531
int myfunc(int my_parameter)
1532
...
1533
@end example
1534

    
1535
fprintf and printf are forbidden in libavformat and libavcodec,
1536
please use av_log() instead.
1537

    
1538
@section Development Policy
1539

    
1540
@enumerate
1541
@item
1542
   You must not commit code which breaks FFmpeg! (Meaning unfinished but
1543
   enabled code which breaks compilation or compiles but does not work or
1544
   breaks the regression tests)
1545
   You can commit unfinished stuff (for testing etc), but it must be disabled
1546
   (#ifdef etc) by default so it does not interfere with other developers'
1547
   work.
1548
@item
1549
   You do not have to over-test things. If it works for you, and you think it
1550
   should work for others, then commit. If your code has problems
1551
   (portability, triggers compiler bugs, unusual environment etc) they will be
1552
   reported and eventually fixed.
1553
@item
1554
   Do not commit unrelated changes together, split them into self-contained
1555
   pieces. Also do not forget that if part B depends on part A, but A does not
1556
   depend on B, then A can and should be committed first and separate from B.
1557
   Keeping changes well split into self-contained parts makes reviewing and
1558
   understanding them on the commit log mailing list easier. This also helps
1559
   in case of debugging later on.
1560
   Also if you have doubts about splitting or not splitting, do not hesitate to
1561
   ask/discuss it on the developer mailing list.
1562
@item
1563
   Do not change behavior of the program (renaming options etc) without
1564
   first discussing it on the ffmpeg-devel mailing list. Do not remove
1565
   functionality from the code. Just improve!
1566

    
1567
   Note: Redundant code can be removed.
1568
@item
1569
   Do not commit changes to the build system (Makefiles, configure script)
1570
   which change behavior, defaults etc, without asking first. The same
1571
   applies to compiler warning fixes, trivial looking fixes and to code
1572
   maintained by other developers. We usually have a reason for doing things
1573
   the way we do. Send your changes as patches to the ffmpeg-devel mailing
1574
   list, and if the code maintainers say OK, you may commit. This does not
1575
   apply to files you wrote and/or maintain.
1576
@item
1577
   We refuse source indentation and other cosmetic changes if they are mixed
1578
   with functional changes, such commits will be rejected and removed. Every
1579
   developer has his own indentation style, you should not change it. Of course
1580
   if you (re)write something, you can use your own style, even though we would
1581
   prefer if the indentation throughout FFmpeg was consistent (Many projects
1582
   force a given indentation style - we do not.). If you really need to make
1583
   indentation changes (try to avoid this), separate them strictly from real
1584
   changes.
1585

    
1586
   NOTE: If you had to put if()@{ .. @} over a large (> 5 lines) chunk of code,
1587
   then either do NOT change the indentation of the inner part within (do not
1588
   move it to the right)! or do so in a separate commit
1589
@item
1590
   Always fill out the commit log message. Describe in a few lines what you
1591
   changed and why. You can refer to mailing list postings if you fix a
1592
   particular bug. Comments such as "fixed!" or "Changed it." are unacceptable.
1593
@item
1594
   If you apply a patch by someone else, include the name and email address in
1595
   the log message. Since the ffmpeg-cvslog mailing list is publicly
1596
   archived you should add some SPAM protection to the email address. Send an
1597
   answer to ffmpeg-devel (or wherever you got the patch from) saying that
1598
   you applied the patch.
1599
@item
1600
   When applying patches that have been discussed (at length) on the mailing
1601
   list, reference the thread in the log message.
1602
@item
1603
    Do NOT commit to code actively maintained by others without permission.
1604
    Send a patch to ffmpeg-devel instead. If noone answers within a reasonable
1605
    timeframe (12h for build failures and security fixes, 3 days small changes,
1606
    1 week for big patches) then commit your patch if you think it is OK.
1607
    Also note, the maintainer can simply ask for more time to review!
1608
@item
1609
    Subscribe to the ffmpeg-cvslog mailing list. The diffs of all commits
1610
    are sent there and reviewed by all the other developers. Bugs and possible
1611
    improvements or general questions regarding commits are discussed there. We
1612
    expect you to react if problems with your code are uncovered.
1613
@item
1614
    Update the documentation if you change behavior or add features. If you are
1615
    unsure how best to do this, send a patch to ffmpeg-devel, the documentation
1616
    maintainer(s) will review and commit your stuff.
1617
@item
1618
    Try to keep important discussions and requests (also) on the public
1619
    developer mailing list, so that all developers can benefit from them.
1620
@item
1621
    Never write to unallocated memory, never write over the end of arrays,
1622
    always check values read from some untrusted source before using them
1623
    as array index or other risky things.
1624
@item
1625
    Remember to check if you need to bump versions for the specific libav
1626
    parts (libavutil, libavcodec, libavformat) you are changing. You need
1627
    to change the version integer and the version string.
1628
    Incrementing the first component means no backward compatibility to
1629
    previous versions (e.g. removal of a function from the public API).
1630
    Incrementing the second component means backward compatible change
1631
    (e.g. addition of a function to the public API).
1632
    Incrementing the third component means a noteworthy binary compatible
1633
    change (e.g. encoder bug fix that matters for the decoder).
1634
@item
1635
    If you add a new codec, remember to update the changelog, add it to
1636
    the supported codecs table in the documentation and bump the second
1637
    component of the @file{libavcodec} version number appropriately. If
1638
    it has a fourcc, add it to @file{libavformat/avienc.c}, even if it
1639
    is only a decoder.
1640
@item
1641
    Do not change code to hide warnings without ensuring that the underlying
1642
    logic is correct and thus the warning was inappropriate.
1643
@end enumerate
1644

    
1645
We think our rules are not too hard. If you have comments, contact us.
1646

    
1647
Note, these rules are mostly borrowed from the MPlayer project.
1648

    
1649
@section Submitting patches
1650

    
1651
First, (@pxref{Coding Rules}) above if you did not yet.
1652

    
1653
When you submit your patch, try to send a unified diff (diff '-up'
1654
option). I cannot read other diffs :-)
1655

    
1656
Also please do not submit patches which contain several unrelated changes.
1657
Split them into individual self-contained patches; this makes reviewing
1658
them much easier.
1659

    
1660
Run the regression tests before submitting a patch so that you can
1661
verify that there are no big problems.
1662

    
1663
Patches should be posted as base64 encoded attachments (or any other
1664
encoding which ensures that the patch will not be trashed during
1665
transmission) to the ffmpeg-devel mailing list, see
1666
@url{http://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel}
1667

    
1668
It also helps quite a bit if you tell us what the patch does (for example
1669
'replaces lrint by lrintf'), and why (for example '*BSD isn't C99 compliant
1670
and has no lrint()')
1671

    
1672
Also please if you send several patches, send each patch as separate mail,
1673
do not attach several unrelated patches to the same mail.
1674

    
1675
@section patch submission checklist
1676

    
1677
@enumerate
1678
@item
1679
    Do the regression tests pass with the patch applied?
1680
@item
1681
    Is the patch a unified diff?
1682
@item
1683
    Is the patch against latest FFmpeg SVN?
1684
@item
1685
    Are you subscribed to ffmpeg-dev?
1686
    (the list is subscribers only due to spam)
1687
@item
1688
    Have you checked that the changes are minimal, so that the same cannot be
1689
    achieved with a smaller patch and/or simpler final code?
1690
@item
1691
    If the change is to speed critical code, did you benchmark it?
1692
@item
1693
    Have you checked that the patch does not introduce buffer overflows or
1694
    other security issues?
1695
@item
1696
    Is the patch created from the root of the source tree, so it can be
1697
    applied with @code{patch -p0}?
1698
@item
1699
    Does the patch not mix functional and cosmetic changes?
1700
@item
1701
    Is the patch attached to the email you send?
1702
@item
1703
    Is the mime type of the patch correct? It should be text/x-diff or
1704
    text/x-patch or at least text/plain and not application/octet-stream.
1705
@item
1706
    If the patch fixes a bug, did you provide a verbose analysis of the bug?
1707
@item
1708
    If the patch fixes a bug, did you provide enough information, including
1709
    a sample, so the bug can be reproduced and the fix can be verified?
1710
@item
1711
    Did you provide a verbose summary about what the patch does change?
1712
@item
1713
    Did you provide a verbose explanation why it changes things like it does?
1714
@item
1715
    Did you provide a verbose summary of the user visible advantages and
1716
    disadvantages if the patch is applied?
1717
@item
1718
    Did you provide an example so we can verify the new feature added by the
1719
    patch easily?
1720
@item
1721
    If you did any benchmarks, did you provide them in the mail?
1722
@item
1723
    If you added a new file, did you insert a license header? It should be
1724
    taken from FFmpeg, not randomly copied and pasted from somewhere else.
1725
@item
1726
    Did you provide a suggestion for a clear commit log message?
1727
@end enumerate
1728

    
1729
@section Patch review process
1730

    
1731
All patches posted to ffmpeg-devel will be reviewed, unless they contain a
1732
clear note that the patch is not for SVN.
1733
Reviews and comments will be posted as replies to the patch on the
1734
mailing list. The patch submitter then has to take care of every comment,
1735
that can be by resubmitting a changed patch or by discussion. Resubmitted
1736
patches will themselves be reviewed like any other patch. If at some point
1737
a patch passes review with no comments then it is approved, that can for
1738
simple and small patches happen immediately while large patches will generally
1739
have to be changed and reviewed many times before they are approved.
1740
After a patch is approved it will be committed to the repository.
1741

    
1742
We will review all submitted patches, but sometimes we are quite busy so
1743
especially for large patches this can take several weeks.
1744

    
1745
When resubmitting patches, please do not make any significant changes
1746
not related to the comments received during review. Such patches will
1747
be rejected. Instead, submit  significant changes or new features as
1748
separate patches.
1749

    
1750
@section Regression tests
1751

    
1752
Before submitting a patch (or committing to the repository), you should at least
1753
test that you did not break anything.
1754

    
1755
The regression tests build a synthetic video stream and a synthetic
1756
audio stream. These are then encoded and decoded with all codecs or
1757
formats. The CRC (or MD5) of each generated file is recorded in a
1758
result file. A 'diff' is launched to compare the reference results and
1759
the result file.
1760

    
1761
The regression tests then go on to test the FFserver code with a
1762
limited set of streams. It is important that this step runs correctly
1763
as well.
1764

    
1765
Run 'make test' to test all the codecs and formats.
1766

    
1767
Run 'make fulltest' to test all the codecs, formats and FFserver.
1768

    
1769
[Of course, some patches may change the results of the regression tests. In
1770
this case, the reference results of the regression tests shall be modified
1771
accordingly].
1772

    
1773
@bye