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\input texinfo @c -*- texinfo -*-
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@settitle FFmpeg Documentation
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@titlepage
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@sp 7
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@center @titlefont{FFmpeg Documentation}
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@sp 3
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@end titlepage
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@chapter Introduction
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FFmpeg is a very fast video and audio converter. It can also grab from
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a live audio/video source.
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The command line interface is designed to be intuitive, in the sense
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that FFmpeg tries to figure out all parameters that can possibly be
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derived automatically. You usually only have to specify the target
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bitrate you want.
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FFmpeg can also convert from any sample rate to any other, and resize
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video on the fly with a high quality polyphase filter.
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@chapter Quick Start
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@c man begin EXAMPLES
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@section Video and Audio grabbing
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FFmpeg can grab video and audio from devices given that you specify the input
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format and device.
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@example
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ffmpeg -f audio_device -i /dev/dsp -f video4linux2 -i /dev/video0 /tmp/out.mpg
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@end example
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Note that you must activate the right video source and channel before
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launching FFmpeg with any TV viewer such as xawtv
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(@url{http://bytesex.org/xawtv/}) by Gerd Knorr. You also
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have to set the audio recording levels correctly with a
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standard mixer.
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@section X11 grabbing
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FFmpeg can grab the X11 display.
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@example
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ffmpeg -f x11grab -s cif -i :0.0 /tmp/out.mpg
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@end example
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0.0 is display.screen number of your X11 server, same as
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the DISPLAY environment variable.
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@example
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ffmpeg -f x11grab -s cif -i :0.0+10,20 /tmp/out.mpg
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@end example
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0.0 is display.screen number of your X11 server, same as the DISPLAY environment
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variable. 10 is the x-offset and 20 the y-offset for the grabbing.
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@section Video and Audio file format conversion
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* FFmpeg can use any supported file format and protocol as input:
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Examples:
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* You can use YUV files as input:
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@example
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ffmpeg -i /tmp/test%d.Y /tmp/out.mpg
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@end example
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It will use the files:
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@example
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/tmp/test0.Y, /tmp/test0.U, /tmp/test0.V,
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/tmp/test1.Y, /tmp/test1.U, /tmp/test1.V, etc...
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@end example
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The Y files use twice the resolution of the U and V files. They are
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raw files, without header. They can be generated by all decent video
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decoders. You must specify the size of the image with the @option{-s} option
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if FFmpeg cannot guess it.
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* You can input from a raw YUV420P file:
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@example
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ffmpeg -i /tmp/test.yuv /tmp/out.avi
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@end example
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test.yuv is a file containing raw YUV planar data. Each frame is composed
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of the Y plane followed by the U and V planes at half vertical and
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horizontal resolution.
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* You can output to a raw YUV420P file:
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@example
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ffmpeg -i mydivx.avi hugefile.yuv
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@end example
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* You can set several input files and output files:
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@example
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ffmpeg -i /tmp/a.wav -s 640x480 -i /tmp/a.yuv /tmp/a.mpg
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@end example
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Converts the audio file a.wav and the raw YUV video file a.yuv
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to MPEG file a.mpg.
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* You can also do audio and video conversions at the same time:
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@example
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ffmpeg -i /tmp/a.wav -ar 22050 /tmp/a.mp2
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@end example
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Converts a.wav to MPEG audio at 22050Hz sample rate.
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* You can encode to several formats at the same time and define a
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mapping from input stream to output streams:
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@example
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ffmpeg -i /tmp/a.wav -ab 64k /tmp/a.mp2 -ab 128k /tmp/b.mp2 -map 0:0 -map 0:0
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@end example
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Converts a.wav to a.mp2 at 64 kbits and to b.mp2 at 128 kbits. '-map
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file:index' specifies which input stream is used for each output
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stream, in the order of the definition of output streams.
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* You can transcode decrypted VOBs
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@example
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ffmpeg -i snatch_1.vob -f avi -vcodec mpeg4 -b 800k -g 300 -bf 2 -acodec libmp3lame -ab 128k snatch.avi
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@end example
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This is a typical DVD ripping example; the input is a VOB file, the
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output an AVI file with MPEG-4 video and MP3 audio. Note that in this
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command we use B-frames so the MPEG-4 stream is DivX5 compatible, and
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GOP size is 300 which means one intra frame every 10 seconds for 29.97fps
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input video. Furthermore, the audio stream is MP3-encoded so you need
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to enable LAME support by passing @code{--enable-libmp3lame} to configure.
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The mapping is particularly useful for DVD transcoding
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to get the desired audio language.
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NOTE: To see the supported input formats, use @code{ffmpeg -formats}.
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@c man end
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@chapter Invocation
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@section Syntax
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The generic syntax is:
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@example
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@c man begin SYNOPSIS
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ffmpeg [[infile options][@option{-i} @var{infile}]]... @{[outfile options] @var{outfile}@}...
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@c man end
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@end example
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@c man begin DESCRIPTION
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As a general rule, options are applied to the next specified
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file. Therefore, order is important, and you can have the same
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option on the command line multiple times. Each occurrence is
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then applied to the next input or output file.
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* To set the video bitrate of the output file to 64kbit/s:
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@example
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ffmpeg -i input.avi -b 64k output.avi
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@end example
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* To force the frame rate of the input and output file to 24 fps:
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@example
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ffmpeg -r 24 -i input.avi output.avi
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@end example
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* To force the frame rate of the output file to 24 fps:
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@example
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ffmpeg -i input.avi -r 24 output.avi
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@end example
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* To force the frame rate of input file to 1 fps and the output file to 24 fps:
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@example
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ffmpeg -r 1 -i input.avi -r 24 output.avi
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@end example
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The format option may be needed for raw input files.
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By default, FFmpeg tries to convert as losslessly as possible: It
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uses the same audio and video parameters for the outputs as the one
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specified for the inputs.
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@c man end
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@c man begin OPTIONS
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@section Main options
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@table @option
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@item -L
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Show license.
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@item -h
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Show help.
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@item -version
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Show version.
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@item -formats
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Show available formats, codecs, protocols, ...
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@item -f fmt
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Force format.
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@item -i filename
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input filename
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@item -y
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Overwrite output files.
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@item -t duration
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Set the recording time in seconds.
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@code{hh:mm:ss[.xxx]} syntax is also supported.
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@item -fs limit_size
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Set the file size limit.
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@item -ss position
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Seek to given time position in seconds.
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@code{hh:mm:ss[.xxx]} syntax is also supported.
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@item -itsoffset offset
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Set the input time offset in seconds.
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@code{[-]hh:mm:ss[.xxx]} syntax is also supported.
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This option affects all the input files that follow it.
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The offset is added to the timestamps of the input files.
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Specifying a positive offset means that the corresponding
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streams are delayed by 'offset' seconds.
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@item -title string
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Set the title.
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@item -timestamp time
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Set the timestamp.
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@item -author string
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Set the author.
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@item -copyright string
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Set the copyright.
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@item -comment string
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Set the comment.
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@item -album string
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Set the album.
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@item -track number
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Set the track.
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@item -year number
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Set the year.
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@item -v verbose
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Control amount of logging.
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@item -target type
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Specify target file type ("vcd", "svcd", "dvd", "dv", "dv50", "pal-vcd",
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"ntsc-svcd", ... ). All the format options (bitrate, codecs,
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buffer sizes) are then set automatically. You can just type:
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@example
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ffmpeg -i myfile.avi -target vcd /tmp/vcd.mpg
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@end example
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Nevertheless you can specify additional options as long as you know
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they do not conflict with the standard, as in:
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@example
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ffmpeg -i myfile.avi -target vcd -bf 2 /tmp/vcd.mpg
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@end example
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@item -dframes number
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Set the number of data frames to record.
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@item -scodec codec
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Force subtitle codec ('copy' to copy stream).
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@item -newsubtitle
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Add a new subtitle stream to the current output stream.
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@item -slang code
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Set the ISO 639 language code (3 letters) of the current subtitle stream.
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@end table
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@section Video Options
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@table @option
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@item -b bitrate
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Set the video bitrate in bit/s (default = 200 kb/s).
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@item -vframes number
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Set the number of video frames to record.
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@item -r fps
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Set frame rate (Hz value, fraction or abbreviation), (default = 25).
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@item -s size
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Set frame size. The format is @samp{wxh} (ffserver default = 160x128, ffmpeg default = same as source).
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The following abbreviations are recognized:
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@table @samp
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@item sqcif
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128x96
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@item qcif
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176x144
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@item cif
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352x288
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@item 4cif
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704x576
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@item qqvga
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160x120
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@item qvga
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320x240
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@item vga
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640x480
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@item svga
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800x600
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@item xga
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1024x768
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@item uxga
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1600x1200
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@item qxga
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2048x1536
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@item sxga
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1280x1024
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@item qsxga
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2560x2048
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@item hsxga
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5120x4096
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@item wvga
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852x480
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@item wxga
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1366x768
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@item wsxga
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1600x1024
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@item wuxga
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1920x1200
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@item woxga
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2560x1600
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@item wqsxga
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3200x2048
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@item wquxga
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3840x2400
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@item whsxga
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6400x4096
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@item whuxga
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7680x4800
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@item cga
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320x200
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@item ega
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640x350
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@item hd480
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852x480
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@item hd720
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1280x720
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@item hd1080
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1920x1080
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@end table
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@item -aspect aspect
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Set aspect ratio (4:3, 16:9 or 1.3333, 1.7777).
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@item -croptop size
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Set top crop band size (in pixels).
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@item -cropbottom size
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Set bottom crop band size (in pixels).
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@item -cropleft size
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Set left crop band size (in pixels).
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@item -cropright size
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Set right crop band size (in pixels).
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@item -padtop size
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Set top pad band size (in pixels).
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@item -padbottom size
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Set bottom pad band size (in pixels).
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@item -padleft size
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Set left pad band size (in pixels).
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@item -padright size
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Set right pad band size (in pixels).
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@item -padcolor (hex color)
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Set color of padded bands. The value for padcolor is expressed
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as a six digit hexadecimal number where the first two digits
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represent red, the middle two digits green and last two digits
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blue (default = 000000 (black)).
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@item -vn
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Disable video recording.
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@item -bt tolerance
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Set video bitrate tolerance (in bit/s).
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@item -maxrate bitrate
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Set max video bitrate tolerance (in bit/s).
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@item -minrate bitrate
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Set min video bitrate tolerance (in bit/s).
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@item -bufsize size
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Set rate control buffer size (in bits).
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@item -vcodec codec
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Force video codec to @var{codec}. Use the @code{copy} special value to
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tell that the raw codec data must be copied as is.
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@item -sameq
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Use same video quality as source (implies VBR).
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@item -pass n
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Select the pass number (1 or 2). It is useful to do two pass
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encoding. The statistics of the video are recorded in the first
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pass and the video is generated at the exact requested bitrate
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in the second pass.
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@item -passlogfile file
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Set two pass logfile name to @var{file}.
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@item -newvideo
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Add a new video stream to the current output stream.
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@end table
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@section Advanced Video Options
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@table @option
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@item -pix_fmt format
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Set pixel format. Use 'list' as parameter to show all the supported
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pixel formats.
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@item -sws_flags flags
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Set SwScaler flags (only available when compiled with SwScaler support).
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@item -g gop_size
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Set the group of pictures size.
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@item -intra
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Use only intra frames.
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@item -vdt n
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Discard threshold.
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@item -qscale q
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Use fixed video quantizer scale (VBR).
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@item -qmin q
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minimum video quantizer scale (VBR)
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@item -qmax q
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maximum video quantizer scale (VBR)
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@item -qdiff q
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maximum difference between the quantizer scales (VBR)
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@item -qblur blur
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video quantizer scale blur (VBR)
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@item -qcomp compression
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video quantizer scale compression (VBR)
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@item -lmin lambda
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minimum video lagrange factor (VBR)
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@item -lmax lambda
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max video lagrange factor (VBR)
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@item -mblmin lambda
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minimum macroblock quantizer scale (VBR)
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@item -mblmax lambda
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maximum macroblock quantizer scale (VBR)
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These four options (lmin, lmax, mblmin, mblmax) use 'lambda' units,
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but you may use the QP2LAMBDA constant to easily convert from 'q' units:
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@example
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ffmpeg -i src.ext -lmax 21*QP2LAMBDA dst.ext
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@end example
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@item -rc_init_cplx complexity
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initial complexity for single pass encoding
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@item -b_qfactor factor
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qp factor between P- and B-frames
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@item -i_qfactor factor
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qp factor between P- and I-frames
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@item -b_qoffset offset
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qp offset between P- and B-frames
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@item -i_qoffset offset
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qp offset between P- and I-frames
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@item -rc_eq equation
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Set rate control equation (@pxref{FFmpeg formula
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evaluator}) (default = @code{tex^qComp}).
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@item -rc_override override
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rate control override for specific intervals
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@item -me method
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Set motion estimation method to @var{method}.
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Available methods are (from lowest to best quality):
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@table @samp
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@item zero
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Try just the (0, 0) vector.
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@item phods
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@item log
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@item x1
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@item epzs
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(default method)
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@item full
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exhaustive search (slow and marginally better than epzs)
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@end table
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@item -dct_algo algo
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Set DCT algorithm to @var{algo}. Available values are:
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@table @samp
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@item 0
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FF_DCT_AUTO (default)
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@item 1
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FF_DCT_FASTINT
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@item 2
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FF_DCT_INT
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@item 3
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FF_DCT_MMX
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@item 4
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FF_DCT_MLIB
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@item 5
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FF_DCT_ALTIVEC
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@end table
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@item -idct_algo algo
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Set IDCT algorithm to @var{algo}. Available values are:
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@table @samp
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@item 0
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FF_IDCT_AUTO (default)
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@item 1
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FF_IDCT_INT
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@item 2
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FF_IDCT_SIMPLE
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@item 3
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FF_IDCT_SIMPLEMMX
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@item 4
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FF_IDCT_LIBMPEG2MMX
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@item 5
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FF_IDCT_PS2
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@item 6
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FF_IDCT_MLIB
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@item 7
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FF_IDCT_ARM
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@item 8
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FF_IDCT_ALTIVEC
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@item 9
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FF_IDCT_SH4
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@item 10
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FF_IDCT_SIMPLEARM
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@end table
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@item -er n
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Set error resilience to @var{n}.
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@table @samp
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@item 1
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FF_ER_CAREFUL (default)
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@item 2
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FF_ER_COMPLIANT
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@item 3
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FF_ER_AGGRESSIVE
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@item 4
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FF_ER_VERY_AGGRESSIVE
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@end table
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@item -ec bit_mask
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Set error concealment to @var{bit_mask}. @var{bit_mask} is a bit mask of
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the following values:
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@table @samp
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@item 1
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FF_EC_GUESS_MVS (default = enabled)
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@item 2
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FF_EC_DEBLOCK (default = enabled)
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@end table
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@item -bf frames
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Use 'frames' B-frames (supported for MPEG-1, MPEG-2 and MPEG-4).
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@item -mbd mode
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macroblock decision
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@table @samp
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@item 0
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FF_MB_DECISION_SIMPLE: Use mb_cmp (cannot change it yet in FFmpeg).
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@item 1
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FF_MB_DECISION_BITS: Choose the one which needs the fewest bits.
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@item 2
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FF_MB_DECISION_RD: rate distortion
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@end table
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@item -4mv
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Use four motion vector by macroblock (MPEG-4 only).
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@item -part
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Use data partitioning (MPEG-4 only).
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@item -bug param
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Work around encoder bugs that are not auto-detected.
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@item -strict strictness
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How strictly to follow the standards.
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@item -aic
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Enable Advanced intra coding (h263+).
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@item -umv
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Enable Unlimited Motion Vector (h263+)
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@item -deinterlace
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Deinterlace pictures.
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@item -ilme
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Force interlacing support in encoder (MPEG-2 and MPEG-4 only).
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Use this option if your input file is interlaced and you want
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to keep the interlaced format for minimum losses.
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The alternative is to deinterlace the input stream with
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@option{-deinterlace}, but deinterlacing introduces losses.
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@item -psnr
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Calculate PSNR of compressed frames.
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@item -vstats
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Dump video coding statistics to @file{vstats_HHMMSS.log}.
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@item -vstats_file file
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Dump video coding statistics to @var{file}.
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@item -vhook module
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Insert video processing @var{module}. @var{module} contains the module
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name and its parameters separated by spaces.
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@item -top n
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top=1/bottom=0/auto=-1 field first
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@item -dc precision
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Intra_dc_precision.
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@item -vtag fourcc/tag
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Force video tag/fourcc.
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@item -qphist
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Show QP histogram.
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@item -vbsf bitstream filter
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Bitstream filters available are "dump_extra", "remove_extra", "noise".
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@end table
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@section Audio Options
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@table @option
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@item -aframes number
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Set the number of audio frames to record.
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@item -ar freq
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Set the audio sampling frequency (default = 44100 Hz).
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@item -ab bitrate
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Set the audio bitrate in bit/s (default = 64k).
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@item -ac channels
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Set the number of audio channels (default = 1).
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@item -an
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Disable audio recording.
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@item -acodec codec
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Force audio codec to @var{codec}. Use the @code{copy} special value to
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specify that the raw codec data must be copied as is.
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@item -newaudio
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Add a new audio track to the output file. If you want to specify parameters,
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do so before @code{-newaudio} (@code{-acodec}, @code{-ab}, etc..).
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Mapping will be done automatically, if the number of output streams is equal to
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the number of input streams, else it will pick the first one that matches. You
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can override the mapping using @code{-map} as usual.
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Example:
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@example
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ffmpeg -i file.mpg -vcodec copy -acodec ac3 -ab 384k test.mpg -acodec mp2 -ab 192k -newaudio
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@end example
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@item -alang code
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Set the ISO 639 language code (3 letters) of the current audio stream.
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@end table
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@section Advanced Audio options:
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@table @option
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@item -atag fourcc/tag
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Force audio tag/fourcc.
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@item -absf bitstream filter
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Bitstream filters available are "dump_extra", "remove_extra", "noise", "mp3comp", "mp3decomp".
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@end table
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@section Subtitle options:
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@table @option
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@item -scodec codec
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Force subtitle codec ('copy' to copy stream).
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@item -newsubtitle
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Add a new subtitle stream to the current output stream.
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@item -slang code
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Set the ISO 639 language code (3 letters) of the current subtitle stream.
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@end table
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@section Audio/Video grab options
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@table @option
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@item -vc channel
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Set video grab channel (DV1394 only).
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@item -tvstd standard
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Set television standard (NTSC, PAL (SECAM)).
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@item -isync
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Synchronize read on input.
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@end table
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@section Advanced options
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@table @option
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@item -map input stream id[:input stream id]
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Set stream mapping from input streams to output streams.
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Just enumerate the input streams in the order you want them in the output.
677
[input stream id] sets the (input) stream to sync against.
678
@item -map_meta_data outfile:infile
679
Set meta data information of outfile from infile.
680
@item -debug
681
Print specific debug info.
682
@item -benchmark
683
Add timings for benchmarking.
684
@item -dump
685
Dump each input packet.
686
@item -hex
687
When dumping packets, also dump the payload.
688
@item -bitexact
689
Only use bit exact algorithms (for codec testing).
690
@item -ps size
691
Set packet size in bits.
692
@item -re
693
Read input at native frame rate. Mainly used to simulate a grab device.
694
@item -loop_input
695
Loop over the input stream. Currently it works only for image
696
streams. This option is used for automatic FFserver testing.
697
@item -loop_output number_of_times
698
Repeatedly loop output for formats that support looping such as animated GIF
699
(0 will loop the output infinitely).
700
@item -threads count
701
Thread count.
702
@item -vsync parameter
703
Video sync method. Video will be stretched/squeezed to match the timestamps,
704
it is done by duplicating and dropping frames. With -map you can select from
705
which stream the timestamps should be taken. You can leave either video or
706
audio unchanged and sync the remaining stream(s) to the unchanged one.
707
@item -async samples_per_second
708
Audio sync method. "Stretches/squeezes" the audio stream to match the timestamps,
709
the parameter is the maximum samples per second by which the audio is changed.
710
-async 1 is a special case where only the start of the audio stream is corrected
711
without any later correction.
712
@end table
713

    
714
@node FFmpeg formula evaluator
715
@section FFmpeg formula evaluator
716

    
717
When evaluating a rate control string, FFmpeg uses an internal formula
718
evaluator.
719

    
720
The following binary operators are available: @code{+}, @code{-},
721
@code{*}, @code{/}, @code{^}.
722

    
723
The following unary operators are available: @code{+}, @code{-},
724
@code{(...)}.
725

    
726
The following functions are available:
727
@table @var
728
@item sinh(x)
729
@item cosh(x)
730
@item tanh(x)
731
@item sin(x)
732
@item cos(x)
733
@item tan(x)
734
@item exp(x)
735
@item log(x)
736
@item squish(x)
737
@item gauss(x)
738
@item abs(x)
739
@item max(x, y)
740
@item min(x, y)
741
@item gt(x, y)
742
@item lt(x, y)
743
@item eq(x, y)
744
@item bits2qp(bits)
745
@item qp2bits(qp)
746
@end table
747

    
748
The following constants are available:
749
@table @var
750
@item PI
751
@item E
752
@item iTex
753
@item pTex
754
@item tex
755
@item mv
756
@item fCode
757
@item iCount
758
@item mcVar
759
@item var
760
@item isI
761
@item isP
762
@item isB
763
@item avgQP
764
@item qComp
765
@item avgIITex
766
@item avgPITex
767
@item avgPPTex
768
@item avgBPTex
769
@item avgTex
770
@end table
771

    
772
@c man end
773

    
774
@ignore
775

    
776
@setfilename ffmpeg
777
@settitle FFmpeg video converter
778

    
779
@c man begin SEEALSO
780
ffserver(1), ffplay(1) and the HTML documentation of @file{ffmpeg}.
781
@c man end
782

    
783
@c man begin AUTHOR
784
Fabrice Bellard
785
@c man end
786

    
787
@end ignore
788

    
789
@section Protocols
790

    
791
The filename can be @file{-} to read from standard input or to write
792
to standard output.
793

    
794
FFmpeg also handles many protocols specified with an URL syntax.
795

    
796
Use 'ffmpeg -formats' to see a list of the supported protocols.
797

    
798
The protocol @code{http:} is currently used only to communicate with
799
FFserver (see the FFserver documentation). When FFmpeg will be a
800
video player it will also be used for streaming :-)
801

    
802
@chapter Tips
803

    
804
@itemize
805
@item For streaming at very low bitrate application, use a low frame rate
806
and a small GOP size. This is especially true for RealVideo where
807
the Linux player does not seem to be very fast, so it can miss
808
frames. An example is:
809

    
810
@example
811
ffmpeg -g 3 -r 3 -t 10 -b 50k -s qcif -f rv10 /tmp/b.rm
812
@end example
813

    
814
@item  The parameter 'q' which is displayed while encoding is the current
815
quantizer. The value 1 indicates that a very good quality could
816
be achieved. The value 31 indicates the worst quality. If q=31 appears
817
too often, it means that the encoder cannot compress enough to meet
818
your bitrate. You must either increase the bitrate, decrease the
819
frame rate or decrease the frame size.
820

    
821
@item If your computer is not fast enough, you can speed up the
822
compression at the expense of the compression ratio. You can use
823
'-me zero' to speed up motion estimation, and '-intra' to disable
824
motion estimation completely (you have only I-frames, which means it
825
is about as good as JPEG compression).
826

    
827
@item To have very low audio bitrates, reduce the sampling frequency
828
(down to 22050 kHz for MPEG audio, 22050 or 11025 for AC3).
829

    
830
@item To have a constant quality (but a variable bitrate), use the option
831
'-qscale n' when 'n' is between 1 (excellent quality) and 31 (worst
832
quality).
833

    
834
@item When converting video files, you can use the '-sameq' option which
835
uses the same quality factor in the encoder as in the decoder.
836
It allows almost lossless encoding.
837

    
838
@end itemize
839

    
840

    
841
@chapter external libraries
842

    
843
FFmpeg can be hooked up with a number of external libraries to add support
844
for more formats. None of them are used by default, their use has to be
845
explicitly requested by passing the appropriate flags to @file{./configure}.
846

    
847
@section AMR
848

    
849
AMR comes in two different flavors, WB and NB. FFmpeg can make use of the
850
AMR WB (floating-point mode) and the AMR NB (floating-point mode) reference
851
decoders and encoders.
852

    
853
Go to @url{http://www.penguin.cz/~utx/amr} and follow the instructions for
854
installing the libraries. Then pass @code{--enable-libamr-nb} and/or
855
@code{--enable-libamr-wb} to configure to enable the libraries.
856

    
857

    
858
@chapter Supported File Formats and Codecs
859

    
860
You can use the @code{-formats} option to have an exhaustive list.
861

    
862
@section File Formats
863

    
864
FFmpeg supports the following file formats through the @code{libavformat}
865
library:
866

    
867
@multitable @columnfractions .4 .1 .1 .4
868
@item Supported File Format @tab Encoding @tab Decoding @tab Comments
869
@item MPEG audio @tab X @tab X
870
@item MPEG-1 systems @tab X  @tab  X
871
@tab muxed audio and video
872
@item MPEG-2 PS @tab X  @tab  X
873
@tab also known as @code{VOB} file
874
@item MPEG-2 TS @tab    @tab  X
875
@tab also known as DVB Transport Stream
876
@item ASF@tab X @tab X
877
@item AVI@tab X @tab X
878
@item WAV@tab X @tab X
879
@item Macromedia Flash@tab X @tab X
880
@tab Only embedded audio is decoded.
881
@item FLV              @tab  X @tab X
882
@tab Macromedia Flash video files
883
@item Real Audio and Video @tab X @tab X
884
@item Raw AC3 @tab X  @tab  X
885
@item Raw MJPEG @tab X  @tab  X
886
@item Raw MPEG video @tab X  @tab  X
887
@item Raw PCM8/16 bits, mulaw/Alaw@tab X  @tab  X
888
@item Raw CRI ADX audio @tab X  @tab  X
889
@item Raw Shorten audio @tab    @tab  X
890
@item SUN AU format @tab X  @tab  X
891
@item NUT @tab X @tab X @tab NUT Open Container Format
892
@item QuickTime        @tab X @tab  X
893
@item MPEG-4           @tab X @tab  X
894
@tab MPEG-4 is a variant of QuickTime.
895
@item Raw MPEG4 video  @tab  X @tab  X
896
@item DV               @tab  X @tab  X
897
@item 4xm              @tab    @tab X
898
@tab 4X Technologies format, used in some games.
899
@item Playstation STR  @tab    @tab X
900
@item Id RoQ           @tab X  @tab X
901
@tab Used in Quake III, Jedi Knight 2, other computer games.
902
@item Interplay MVE    @tab    @tab X
903
@tab Format used in various Interplay computer games.
904
@item WC3 Movie        @tab    @tab X
905
@tab Multimedia format used in Origin's Wing Commander III computer game.
906
@item Sega FILM/CPK    @tab    @tab X
907
@tab Used in many Sega Saturn console games.
908
@item Westwood Studios VQA/AUD  @tab    @tab X
909
@tab Multimedia formats used in Westwood Studios games.
910
@item Id Cinematic (.cin) @tab    @tab X
911
@tab Used in Quake II.
912
@item FLIC format      @tab    @tab X
913
@tab .fli/.flc files
914
@item Sierra VMD       @tab    @tab X
915
@tab Used in Sierra CD-ROM games.
916
@item Sierra Online    @tab    @tab X
917
@tab .sol files used in Sierra Online games.
918
@item Matroska         @tab    @tab X
919
@item Electronic Arts Multimedia    @tab    @tab X
920
@tab Used in various EA games; files have extensions like WVE and UV2.
921
@item Nullsoft Video (NSV) format @tab    @tab X
922
@item ADTS AAC audio @tab X @tab X
923
@item Creative VOC @tab X @tab X @tab Created for the Sound Blaster Pro.
924
@item American Laser Games MM  @tab    @tab X
925
@tab Multimedia format used in games like Mad Dog McCree
926
@item AVS @tab    @tab X
927
@tab Multimedia format used by the Creature Shock game.
928
@item Smacker @tab    @tab X
929
@tab Multimedia format used by many games.
930
@item GXF @tab  X @tab X
931
@tab General eXchange Format SMPTE 360M, used by Thomson Grass Valley playout servers.
932
@item CIN @tab    @tab X
933
@tab Multimedia format used by Delphine Software games.
934
@item MXF @tab    @tab X
935
@tab Material eXchange Format SMPTE 377M, used by D-Cinema, broadcast industry.
936
@item SEQ @tab    @tab X
937
@tab Tiertex .seq files used in the DOS CDROM version of the game Flashback.
938
@item DXA @tab    @tab X
939
@tab This format is used in non-Windows version of Feeble Files game and
940
different game cutscenes repacked for use with ScummVM.
941
@item THP @tab    @tab X
942
@tab Used on the Nintendo GameCube.
943
@item C93 @tab    @tab X
944
@tab Used in the game Cyberia from Interplay.
945
@item Bethsoft VID @tab    @tab X
946
@tab Used in some games from Bethesda Softworks.
947
@item CRYO APC @tab    @tab X
948
@tab Audio format used in some games by CRYO Interactive Entertainment.
949
@end multitable
950

    
951
@code{X} means that encoding (resp. decoding) is supported.
952

    
953
@section Image Formats
954

    
955
FFmpeg can read and write images for each frame of a video sequence. The
956
following image formats are supported:
957

    
958
@multitable @columnfractions .4 .1 .1 .4
959
@item Supported Image Format @tab Encoding @tab Decoding @tab Comments
960
@item PGM, PPM     @tab X @tab X
961
@item PAM          @tab X @tab X @tab PAM is a PNM extension with alpha support.
962
@item PGMYUV       @tab X @tab X @tab PGM with U and V components in YUV 4:2:0
963
@item JPEG         @tab X @tab X @tab Progressive JPEG is not supported.
964
@item .Y.U.V       @tab X @tab X @tab one raw file per component
965
@item animated GIF @tab X @tab X @tab Only uncompressed GIFs are generated.
966
@item PNG          @tab X @tab X @tab 2 bit and 4 bit/pixel not supported yet.
967
@item Targa        @tab   @tab X @tab Targa (.TGA) image format.
968
@item TIFF         @tab X @tab X @tab YUV, JPEG and some extension is not supported yet.
969
@item SGI          @tab X @tab X @tab SGI RGB image format
970
@item PTX          @tab   @tab X @tab V.Flash PTX format
971
@end multitable
972

    
973
@code{X} means that encoding (resp. decoding) is supported.
974

    
975
@section Video Codecs
976

    
977
@multitable @columnfractions .4 .1 .1 .4
978
@item Supported Codec @tab Encoding @tab Decoding @tab Comments
979
@item MPEG-1 video           @tab  X  @tab  X
980
@item MPEG-2 video           @tab  X  @tab  X
981
@item MPEG-4                 @tab  X  @tab  X
982
@item MSMPEG4 V1             @tab  X  @tab  X
983
@item MSMPEG4 V2             @tab  X  @tab  X
984
@item MSMPEG4 V3             @tab  X  @tab  X
985
@item WMV7                   @tab  X  @tab  X
986
@item WMV8                   @tab  X  @tab  X @tab not completely working
987
@item WMV9                   @tab     @tab  X @tab not completely working
988
@item VC1                    @tab     @tab  X
989
@item H.261                  @tab  X  @tab  X
990
@item H.263(+)               @tab  X  @tab  X @tab also known as RealVideo 1.0
991
@item H.264                  @tab     @tab  X
992
@item RealVideo 1.0          @tab  X  @tab  X
993
@item RealVideo 2.0          @tab  X  @tab  X
994
@item MJPEG                  @tab  X  @tab  X
995
@item lossless MJPEG         @tab  X  @tab  X
996
@item JPEG-LS                @tab  X  @tab  X @tab fourcc: MJLS, lossless and near-lossless is supported
997
@item Apple MJPEG-B          @tab     @tab  X
998
@item Sunplus MJPEG          @tab     @tab  X @tab fourcc: SP5X
999
@item DV                     @tab  X  @tab  X
1000
@item HuffYUV                @tab  X  @tab  X
1001
@item FFmpeg Video 1         @tab  X  @tab  X @tab experimental lossless codec (fourcc: FFV1)
1002
@item FFmpeg Snow            @tab  X  @tab  X @tab experimental wavelet codec (fourcc: SNOW)
1003
@item Asus v1                @tab  X  @tab  X @tab fourcc: ASV1
1004
@item Asus v2                @tab  X  @tab  X @tab fourcc: ASV2
1005
@item Creative YUV           @tab     @tab  X @tab fourcc: CYUV
1006
@item Sorenson Video 1       @tab  X  @tab  X @tab fourcc: SVQ1
1007
@item Sorenson Video 3       @tab     @tab  X @tab fourcc: SVQ3
1008
@item On2 VP3                @tab     @tab  X @tab still experimental
1009
@item On2 VP5                @tab     @tab  X @tab fourcc: VP50
1010
@item On2 VP6                @tab     @tab  X @tab fourcc: VP60,VP61,VP62
1011
@item Theora                 @tab  X  @tab  X @tab still experimental
1012
@item Intel Indeo 3          @tab     @tab  X
1013
@item FLV                    @tab  X  @tab  X @tab Sorenson H.263 used in Flash
1014
@item Flash Screen Video     @tab  X  @tab  X @tab fourcc: FSV1
1015
@item ATI VCR1               @tab     @tab  X @tab fourcc: VCR1
1016
@item ATI VCR2               @tab     @tab  X @tab fourcc: VCR2
1017
@item Cirrus Logic AccuPak   @tab     @tab  X @tab fourcc: CLJR
1018
@item 4X Video               @tab     @tab  X @tab Used in certain computer games.
1019
@item Sony Playstation MDEC  @tab     @tab  X
1020
@item Id RoQ                 @tab     @tab  X @tab Used in Quake III, Jedi Knight 2, other computer games.
1021
@item Xan/WC3                @tab     @tab  X @tab Used in Wing Commander III .MVE files.
1022
@item Interplay Video        @tab     @tab  X @tab Used in Interplay .MVE files.
1023
@item Apple Animation        @tab     @tab  X @tab fourcc: 'rle '
1024
@item Apple Graphics         @tab     @tab  X @tab fourcc: 'smc '
1025
@item Apple Video            @tab     @tab  X @tab fourcc: rpza
1026
@item Apple QuickDraw        @tab     @tab  X @tab fourcc: qdrw
1027
@item Cinepak                @tab     @tab  X
1028
@item Microsoft RLE          @tab     @tab  X
1029
@item Microsoft Video-1      @tab     @tab  X
1030
@item Westwood VQA           @tab     @tab  X
1031
@item Id Cinematic Video     @tab     @tab  X @tab Used in Quake II.
1032
@item Planar RGB             @tab     @tab  X @tab fourcc: 8BPS
1033
@item FLIC video             @tab     @tab  X
1034
@item Duck TrueMotion v1     @tab     @tab  X @tab fourcc: DUCK
1035
@item Duck TrueMotion v2     @tab     @tab  X @tab fourcc: TM20
1036
@item VMD Video              @tab     @tab  X @tab Used in Sierra VMD files.
1037
@item MSZH                   @tab     @tab  X @tab Part of LCL
1038
@item ZLIB                   @tab  X  @tab  X @tab Part of LCL, encoder experimental
1039
@item TechSmith Camtasia     @tab     @tab  X @tab fourcc: TSCC
1040
@item IBM Ultimotion         @tab     @tab  X @tab fourcc: ULTI
1041
@item Miro VideoXL           @tab     @tab  X @tab fourcc: VIXL
1042
@item QPEG                   @tab     @tab  X @tab fourccs: QPEG, Q1.0, Q1.1
1043
@item LOCO                   @tab     @tab  X @tab
1044
@item Winnov WNV1            @tab     @tab  X @tab
1045
@item Autodesk Animator Studio Codec  @tab     @tab  X @tab fourcc: AASC
1046
@item Fraps FPS1             @tab     @tab  X @tab
1047
@item CamStudio              @tab     @tab  X @tab fourcc: CSCD
1048
@item American Laser Games Video  @tab    @tab X @tab Used in games like Mad Dog McCree
1049
@item ZMBV                   @tab   X @tab  X @tab Encoder works only on PAL8
1050
@item AVS Video              @tab     @tab  X @tab Video encoding used by the Creature Shock game.
1051
@item Smacker Video          @tab     @tab  X @tab Video encoding used in Smacker.
1052
@item RTjpeg                 @tab     @tab  X @tab Video encoding used in NuppelVideo files.
1053
@item KMVC                   @tab     @tab  X @tab Codec used in Worms games.
1054
@item VMware Video           @tab     @tab  X @tab Codec used in videos captured by VMware.
1055
@item Cin Video              @tab     @tab  X @tab Codec used in Delphine Software games.
1056
@item Tiertex Seq Video      @tab     @tab  X @tab Codec used in DOS CDROM FlashBack game.
1057
@item DXA Video              @tab     @tab  X @tab Codec originally used in Feeble Files game.
1058
@item AVID DNxHD             @tab     @tab  X @tab aka SMPTE VC3
1059
@item C93 Video              @tab     @tab  X @tab Codec used in Cyberia game.
1060
@item THP                    @tab     @tab  X @tab Used on the Nintendo GameCube.
1061
@item Bethsoft VID           @tab     @tab  X @tab Used in some games from Bethesda Softworks.
1062
@item Renderware TXD         @tab     @tab  X @tab Texture dictionaries used by the Renderware Engine.
1063
@end multitable
1064

    
1065
@code{X} means that encoding (resp. decoding) is supported.
1066

    
1067
@section Audio Codecs
1068

    
1069
@multitable @columnfractions .4 .1 .1 .1 .7
1070
@item Supported Codec @tab Encoding @tab Decoding @tab Comments
1071
@item MPEG audio layer 2     @tab  IX  @tab  IX
1072
@item MPEG audio layer 1/3   @tab IX   @tab  IX
1073
@tab MP3 encoding is supported through the external library LAME.
1074
@item AC3                    @tab  IX  @tab  IX
1075
@tab liba52 is used internally for decoding.
1076
@item Vorbis                 @tab  X   @tab  X
1077
@item WMA V1/V2              @tab X    @tab X
1078
@item AAC                    @tab X    @tab X
1079
@tab Supported through the external library libfaac/libfaad.
1080
@item Microsoft ADPCM        @tab X    @tab X
1081
@item MS IMA ADPCM           @tab X    @tab X
1082
@item QT IMA ADPCM           @tab      @tab X
1083
@item 4X IMA ADPCM           @tab      @tab X
1084
@item G.726  ADPCM           @tab X    @tab X
1085
@item Duck DK3 IMA ADPCM     @tab      @tab X
1086
@tab Used in some Sega Saturn console games.
1087
@item Duck DK4 IMA ADPCM     @tab      @tab X
1088
@tab Used in some Sega Saturn console games.
1089
@item Westwood Studios IMA ADPCM @tab      @tab X
1090
@tab Used in Westwood Studios games like Command and Conquer.
1091
@item SMJPEG IMA ADPCM       @tab      @tab X
1092
@tab Used in certain Loki game ports.
1093
@item CD-ROM XA ADPCM        @tab      @tab X
1094
@item CRI ADX ADPCM          @tab X    @tab X
1095
@tab Used in Sega Dreamcast games.
1096
@item Electronic Arts ADPCM  @tab      @tab X
1097
@tab Used in various EA titles.
1098
@item Creative ADPCM         @tab      @tab X
1099
@tab 16 -> 4, 8 -> 4, 8 -> 3, 8 -> 2
1100
@item THP ADPCM              @tab      @tab X
1101
@tab Used on the Nintendo GameCube.
1102
@item RA144                  @tab      @tab X
1103
@tab Real 14400 bit/s codec
1104
@item RA288                  @tab      @tab X
1105
@tab Real 28800 bit/s codec
1106
@item RADnet                 @tab X    @tab IX
1107
@tab Real low bitrate AC3 codec, liba52 is used for decoding.
1108
@item AMR-NB                 @tab X    @tab X
1109
@tab Supported through an external library.
1110
@item AMR-WB                 @tab X    @tab X
1111
@tab Supported through an external library.
1112
@item DV audio               @tab      @tab X
1113
@item Id RoQ DPCM            @tab X    @tab X
1114
@tab Used in Quake III, Jedi Knight 2, other computer games.
1115
@item Interplay MVE DPCM     @tab      @tab X
1116
@tab Used in various Interplay computer games.
1117
@item Xan DPCM               @tab      @tab X
1118
@tab Used in Origin's Wing Commander IV AVI files.
1119
@item Sierra Online DPCM     @tab      @tab X
1120
@tab Used in Sierra Online game audio files.
1121
@item Apple MACE 3           @tab      @tab X
1122
@item Apple MACE 6           @tab      @tab X
1123
@item FLAC lossless audio    @tab X    @tab X
1124
@item Shorten lossless audio @tab      @tab X
1125
@item Apple lossless audio   @tab      @tab X
1126
@tab QuickTime fourcc 'alac'
1127
@item FFmpeg Sonic           @tab X    @tab X
1128
@tab experimental lossy/lossless codec
1129
@item Qdesign QDM2           @tab      @tab X
1130
@tab there are still some distortions
1131
@item Real COOK              @tab      @tab X
1132
@tab All versions except 5.1 are supported
1133
@item DSP Group TrueSpeech   @tab      @tab X
1134
@item True Audio (TTA)       @tab      @tab X
1135
@item Smacker Audio          @tab      @tab X
1136
@item WavPack Audio          @tab      @tab X
1137
@item Cin Audio              @tab      @tab X
1138
@tab Codec used in Delphine Software games.
1139
@item Intel Music Coder      @tab      @tab X
1140
@item Musepack               @tab      @tab X
1141
@tab Only SV7 is supported
1142
@item DT$ Coherent Audio     @tab      @tab X
1143
@item ATRAC 3                @tab      @tab X
1144
@end multitable
1145

    
1146
@code{X} means that encoding (resp. decoding) is supported.
1147

    
1148
@code{I} means that an integer-only version is available, too (ensures high
1149
performance on systems without hardware floating point support).
1150

    
1151
@chapter Platform Specific information
1152

    
1153
@section BSD
1154

    
1155
BSD make will not build FFmpeg, you need to install and use GNU Make
1156
(@file{gmake}).
1157

    
1158
@section Windows
1159

    
1160
To get help and instructions for using FFmpeg under Windows, check out
1161
the FFmpeg Windows Help Forum at
1162
@url{http://arrozcru.no-ip.org/ffmpeg/}.
1163

    
1164
@subsection Native Windows compilation
1165

    
1166
@itemize
1167
@item Install the current versions of MSYS and MinGW from
1168
@url{http://www.mingw.org/}. You can find detailed installation
1169
instructions in the download section and the FAQ.
1170

    
1171
NOTE: Use at least bash 3.1. Older versions are known to be failing on the
1172
configure script.
1173

    
1174
@item If you want to test the FFplay, also download
1175
the MinGW development library of SDL 1.2.x
1176
(@file{SDL-devel-1.2.x-mingw32.tar.gz}) from
1177
@url{http://www.libsdl.org}. Unpack it in a temporary directory, and
1178
unpack the archive @file{i386-mingw32msvc.tar.gz} in the MinGW tool
1179
directory. Edit the @file{sdl-config} script so that it gives the
1180
correct SDL directory when invoked.
1181

    
1182
@item Extract the current version of FFmpeg.
1183

    
1184
@item Start the MSYS shell (file @file{msys.bat}).
1185

    
1186
@item Change to the FFmpeg directory and follow
1187
 the instructions of how to compile FFmpeg (file
1188
@file{INSTALL}). Usually, launching @file{./configure} and @file{make}
1189
suffices. If you have problems using SDL, verify that
1190
@file{sdl-config} can be launched from the MSYS command line.
1191

    
1192
@item You can install FFmpeg in @file{Program Files/FFmpeg} by typing
1193
@file{make install}. Do not forget to copy @file{SDL.dll} to the place
1194
you launch @file{ffplay} from.
1195

    
1196
@end itemize
1197

    
1198
Notes:
1199
@itemize
1200

    
1201
@item The target @file{make wininstaller} can be used to create a
1202
Nullsoft based Windows installer for FFmpeg and FFplay. @file{SDL.dll}
1203
must be copied to the FFmpeg directory in order to build the
1204
installer.
1205

    
1206
@item By using @code{./configure --enable-shared} when configuring FFmpeg,
1207
you can build @file{avcodec.dll} and @file{avformat.dll}. With
1208
@code{make install} you install the FFmpeg DLLs and the associated
1209
headers in @file{Program Files/FFmpeg}.
1210

    
1211
@item Visual C++ compatibility: If you used @code{./configure --enable-shared}
1212
when configuring FFmpeg, FFmpeg tries to use the Microsoft Visual
1213
C++ @code{lib} tool to build @code{avcodec.lib} and
1214
@code{avformat.lib}. With these libraries you can link your Visual C++
1215
code directly with the FFmpeg DLLs (see below).
1216

    
1217
@end itemize
1218

    
1219
@subsection Visual C++ compatibility
1220

    
1221
FFmpeg will not compile under Visual C++ -- and it has too many
1222
dependencies on the GCC compiler to make a port viable. However,
1223
if you want to use the FFmpeg libraries in your own applications,
1224
you can still compile those applications using Visual C++. An
1225
important restriction to this is that you have to use the
1226
dynamically linked versions of the FFmpeg libraries (i.e. the
1227
DLLs), and you have to make sure that Visual-C++-compatible
1228
import libraries are created during the FFmpeg build process.
1229

    
1230
This description of how to use the FFmpeg libraries with Visual C++ is
1231
based on Visual C++ 2005 Express Edition Beta 2. If you have a different
1232
version, you might have to modify the procedures slightly.
1233

    
1234
Here are the step-by-step instructions for building the FFmpeg libraries
1235
so they can be used with Visual C++:
1236

    
1237
@enumerate
1238

    
1239
@item Install Visual C++ (if you have not done so already).
1240

    
1241
@item Install MinGW and MSYS as described above.
1242

    
1243
@item Add a call to @file{vcvars32.bat} (which sets up the environment
1244
variables for the Visual C++ tools) as the first line of
1245
@file{msys.bat}. The standard location for @file{vcvars32.bat} is
1246
@file{C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat},
1247
and the standard location for @file{msys.bat} is
1248
@file{C:\msys\1.0\msys.bat}. If this corresponds to your setup, add the
1249
following line as the first line of @file{msys.bat}:
1250

    
1251
@code{call "C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat"}
1252

    
1253
@item Start the MSYS shell (file @file{msys.bat}) and type @code{link.exe}.
1254
If you get a help message with the command line options of @code{link.exe},
1255
this means your environment variables are set up correctly, the
1256
Microsoft linker is on the path and will be used by FFmpeg to
1257
create Visual-C++-compatible import libraries.
1258

    
1259
@item Extract the current version of FFmpeg and change to the FFmpeg directory.
1260

    
1261
@item Type the command
1262
@code{./configure --enable-shared --disable-static --enable-memalign-hack}
1263
to configure and, if that did not produce any errors,
1264
type @code{make} to build FFmpeg.
1265

    
1266
@item The subdirectories @file{libavformat}, @file{libavcodec}, and
1267
@file{libavutil} should now contain the files @file{avformat.dll},
1268
@file{avformat.lib}, @file{avcodec.dll}, @file{avcodec.lib},
1269
@file{avutil.dll}, and @file{avutil.lib}, respectively. Copy the three
1270
DLLs to your System32 directory (typically @file{C:\Windows\System32}).
1271

    
1272
@end enumerate
1273

    
1274
And here is how to use these libraries with Visual C++:
1275

    
1276
@enumerate
1277

    
1278
@item Create a new console application ("File / New / Project") and then
1279
select "Win32 Console Application". On the appropriate page of the
1280
Application Wizard, uncheck the "Precompiled headers" option.
1281

    
1282
@item Write the source code for your application, or, for testing, just
1283
copy the code from an existing sample application into the source file
1284
that Visual C++ has already created for you. (Note that your source
1285
filehas to have a @code{.cpp} extension; otherwise, Visual C++ will not
1286
compile the FFmpeg headers correctly because in C mode, it does not
1287
recognize the @code{inline} keyword.)  For example, you can copy
1288
@file{output_example.c} from the FFmpeg distribution (but you will
1289
have to make minor modifications so the code will compile under
1290
C++, see below).
1291

    
1292
@item Open the "Project / Properties" dialog box. In the "Configuration"
1293
combo box, select "All Configurations" so that the changes you make will
1294
affect both debug and release builds. In the tree view on the left hand
1295
side, select "C/C++ / General", then edit the "Additional Include
1296
Directories" setting to contain the complete paths to the
1297
@file{libavformat}, @file{libavcodec}, and @file{libavutil}
1298
subdirectories of your FFmpeg directory. Note that the directories have
1299
to be separated using semicolons. Now select "Linker / General" from the
1300
tree view and edit the "Additional Library Directories" setting to
1301
contain the same three directories.
1302

    
1303
@item Still in the "Project / Properties" dialog box, select "Linker / Input"
1304
from the tree view, then add the files @file{avformat.lib},
1305
@file{avcodec.lib}, and @file{avutil.lib} to the end of the "Additional
1306
Dependencies". Note that the names of the libraries have to be separated
1307
using spaces.
1308

    
1309
@item Now, select "C/C++ / Code Generation" from the tree view. Select
1310
"Debug" in the "Configuration" combo box. Make sure that "Runtime
1311
Library" is set to "Multi-threaded Debug DLL". Then, select "Release" in
1312
the "Configuration" combo box and make sure that "Runtime Library" is
1313
set to "Multi-threaded DLL".
1314

    
1315
@item Click "OK" to close the "Project / Properties" dialog box and build
1316
the application. Hopefully, it should compile and run cleanly. If you
1317
used @file{output_example.c} as your sample application, you will get a
1318
few compiler errors, but they are easy to fix. The first type of error
1319
occurs because Visual C++ does not allow an @code{int} to be converted to
1320
an @code{enum} without a cast. To solve the problem, insert the required
1321
casts (this error occurs once for a @code{CodecID} and once for a
1322
@code{CodecType}).  The second type of error occurs because C++ requires
1323
the return value of @code{malloc} to be cast to the exact type of the
1324
pointer it is being assigned to. Visual C++ will complain that, for
1325
example, @code{(void *)} is being assigned to @code{(uint8_t *)} without
1326
an explicit cast. So insert an explicit cast in these places to silence
1327
the compiler. The third type of error occurs because the @code{snprintf}
1328
library function is called @code{_snprintf} under Visual C++.  So just
1329
add an underscore to fix the problem. With these changes,
1330
@file{output_example.c} should compile under Visual C++, and the
1331
resulting executable should produce valid video files.
1332

    
1333
@end enumerate
1334

    
1335
@subsection Cross compilation for Windows with Linux
1336

    
1337
You must use the MinGW cross compilation tools available at
1338
@url{http://www.mingw.org/}.
1339

    
1340
Then configure FFmpeg with the following options:
1341
@example
1342
./configure --target-os=mingw32 --cross-prefix=i386-mingw32msvc-
1343
@end example
1344
(you can change the cross-prefix according to the prefix chosen for the
1345
MinGW tools).
1346

    
1347
Then you can easily test FFmpeg with Wine
1348
(@url{http://www.winehq.com/}).
1349

    
1350
@subsection Compilation under Cygwin
1351

    
1352
Cygwin works very much like Unix.
1353

    
1354
Just install your Cygwin with all the "Base" packages, plus the
1355
following "Devel" ones:
1356
@example
1357
binutils, gcc-core, make, subversion
1358
@end example
1359

    
1360
Do not install binutils-20060709-1 (they are buggy on shared builds);
1361
use binutils-20050610-1 instead.
1362

    
1363
Then run
1364

    
1365
@example
1366
./configure --enable-static --disable-shared
1367
@end example
1368

    
1369
to make a static build or
1370

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

    
1375
to build shared libraries.
1376

    
1377
If you want to build FFmpeg with additional libraries, download Cygwin
1378
"Devel" packages for Ogg and Vorbis from any Cygwin packages repository
1379
and/or SDL, xvid, faac, faad2 packages from Cygwin Ports,
1380
(@url{http://cygwinports.dotsrc.org/}).
1381

    
1382
@subsection Crosscompilation for Windows under Cygwin
1383

    
1384
With Cygwin you can create Windows binaries that do not need the cygwin1.dll.
1385

    
1386
Just install your Cygwin as explained before, plus these additional
1387
"Devel" packages:
1388
@example
1389
gcc-mingw-core, mingw-runtime, mingw-zlib
1390
@end example
1391

    
1392
and add some special flags to your configure invocation.
1393

    
1394
For a static build run
1395
@example
1396
./configure --target-os=mingw32 --enable-memalign-hack --enable-static --disable-shared --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
1397
@end example
1398

    
1399
and for a build with shared libraries
1400
@example
1401
./configure --target-os=mingw32 --enable-memalign-hack --enable-shared --disable-static --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
1402
@end example
1403

    
1404
@section BeOS
1405

    
1406
The configure script should guess the configuration itself.
1407
Networking support is currently not finished.
1408
errno issues fixed by Andrew Bachmann.
1409

    
1410
Old stuff:
1411

    
1412
Fran├žois Revol - revol at free dot fr - April 2002
1413

    
1414
The configure script should guess the configuration itself,
1415
however I still did not test building on the net_server version of BeOS.
1416

    
1417
FFserver is broken (needs poll() implementation).
1418

    
1419
There are still issues with errno codes, which are negative in BeOS, and
1420
that FFmpeg negates when returning. This ends up turning errors into
1421
valid results, then crashes.
1422
(To be fixed)
1423

    
1424
@chapter Developers Guide
1425

    
1426
@section API
1427
@itemize @bullet
1428
@item libavcodec is the library containing the codecs (both encoding and
1429
decoding). Look at @file{libavcodec/apiexample.c} to see how to use it.
1430

    
1431
@item libavformat is the library containing the file format handling (mux and
1432
demux code for several formats). Look at @file{ffplay.c} to use it in a
1433
player. See @file{output_example.c} to use it to generate audio or video
1434
streams.
1435

    
1436
@end itemize
1437

    
1438
@section Integrating libavcodec or libavformat in your program
1439

    
1440
You can integrate all the source code of the libraries to link them
1441
statically to avoid any version problem. All you need is to provide a
1442
'config.mak' and a 'config.h' in the parent directory. See the defines
1443
generated by ./configure to understand what is needed.
1444

    
1445
You can use libavcodec or libavformat in your commercial program, but
1446
@emph{any patch you make must be published}. The best way to proceed is
1447
to send your patches to the FFmpeg mailing list.
1448

    
1449
@node Coding Rules
1450
@section Coding Rules
1451

    
1452
FFmpeg is programmed in the ISO C90 language with a few additional
1453
features from ISO C99, namely:
1454
@itemize @bullet
1455
@item
1456
the @samp{inline} keyword;
1457
@item
1458
@samp{//} comments;
1459
@item
1460
designated struct initializers (@samp{struct s x = @{ .i = 17 @};})
1461
@item
1462
compound literals (@samp{x = (struct s) @{ 17, 23 @};})
1463
@end itemize
1464

    
1465
These features are supported by all compilers we care about, so we will not
1466
accept patches to remove their use unless they absolutely do not impair
1467
clarity and performance.
1468

    
1469
All code must compile with GCC 2.95 and GCC 3.3. Currently, FFmpeg also
1470
compiles with several other compilers, such as the Compaq ccc compiler
1471
or Sun Studio 9, and we would like to keep it that way unless it would
1472
be exceedingly involved. To ensure compatibility, please do not use any
1473
additional C99 features or GCC extensions. Especially watch out for:
1474
@itemize @bullet
1475
@item
1476
mixing statements and declarations;
1477
@item
1478
@samp{long long} (use @samp{int64_t} instead);
1479
@item
1480
@samp{__attribute__} not protected by @samp{#ifdef __GNUC__} or similar;
1481
@item
1482
GCC statement expressions (@samp{(x = (@{ int y = 4; y; @})}).
1483
@end itemize
1484

    
1485
Indent size is 4.
1486
The presentation is the one specified by 'indent -i4 -kr -nut'.
1487
The TAB character is forbidden outside of Makefiles as is any
1488
form of trailing whitespace. Commits containing either will be
1489
rejected by the Subversion repository.
1490

    
1491
Main priority in FFmpeg is simplicity and small code size (=less
1492
bugs).
1493

    
1494
Comments: Use the JavaDoc/Doxygen
1495
format (see examples below) so that code documentation
1496
can be generated automatically. All nontrivial functions should have a comment
1497
above them explaining what the function does, even if it is just one sentence.
1498
All structures and their member variables should be documented, too.
1499
@example
1500
/**
1501
 * @@file mpeg.c
1502
 * MPEG codec.
1503
 * @@author ...
1504
 */
1505

    
1506
/**
1507
 * Summary sentence.
1508
 * more text ...
1509
 * ...
1510
 */
1511
typedef struct Foobar@{
1512
    int var1; /**< var1 description */
1513
    int var2; ///< var2 description
1514
    /** var3 description */
1515
    int var3;
1516
@} Foobar;
1517

    
1518
/**
1519
 * Summary sentence.
1520
 * more text ...
1521
 * ...
1522
 * @@param my_parameter description of my_parameter
1523
 * @@return return value description
1524
 */
1525
int myfunc(int my_parameter)
1526
...
1527
@end example
1528

    
1529
fprintf and printf are forbidden in libavformat and libavcodec,
1530
please use av_log() instead.
1531

    
1532
@section Development Policy
1533

    
1534
@enumerate
1535
@item
1536
   You must not commit code which breaks FFmpeg! (Meaning unfinished but
1537
   enabled code which breaks compilation or compiles but does not work or
1538
   breaks the regression tests)
1539
   You can commit unfinished stuff (for testing etc), but it must be disabled
1540
   (#ifdef etc) by default so it does not interfere with other developers'
1541
   work.
1542
@item
1543
   You do not have to over-test things. If it works for you, and you think it
1544
   should work for others, then commit. If your code has problems
1545
   (portability, triggers compiler bugs, unusual environment etc) they will be
1546
   reported and eventually fixed.
1547
@item
1548
   Do not commit unrelated changes together, split them into self-contained
1549
   pieces. Also do not forget that if part B depends on part A, but A does not
1550
   depend on B, then A can and should be committed first and separate from B.
1551
   Keeping changes well split into self-contained parts makes reviewing and
1552
   understanding them on the commit log mailing list easier. This also helps
1553
   in case of debugging later on.
1554
   Also if you have doubts about splitting or not splitting, do not hesitate to
1555
   ask/discuss it on the developer mailing list.
1556
@item
1557
   Do not change behavior of the program (renaming options etc) without
1558
   first discussing it on the ffmpeg-devel mailing list. Do not remove
1559
   functionality from the code. Just improve!
1560

    
1561
   Note: Redundant code can be removed.
1562
@item
1563
   Do not commit changes to the build system (Makefiles, configure script)
1564
   which change behavior, defaults etc, without asking first. The same
1565
   applies to compiler warning fixes, trivial looking fixes and to code
1566
   maintained by other developers. We usually have a reason for doing things
1567
   the way we do. Send your changes as patches to the ffmpeg-devel mailing
1568
   list, and if the code maintainers say OK, you may commit. This does not
1569
   apply to files you wrote and/or maintain.
1570
@item
1571
   We refuse source indentation and other cosmetic changes if they are mixed
1572
   with functional changes, such commits will be rejected and removed. Every
1573
   developer has his own indentation style, you should not change it. Of course
1574
   if you (re)write something, you can use your own style, even though we would
1575
   prefer if the indentation throughout FFmpeg was consistent (Many projects
1576
   force a given indentation style - we do not.). If you really need to make
1577
   indentation changes (try to avoid this), separate them strictly from real
1578
   changes.
1579

    
1580
   NOTE: If you had to put if()@{ .. @} over a large (> 5 lines) chunk of code,
1581
   then either do NOT change the indentation of the inner part within (do not
1582
   move it to the right)! or do so in a separate commit
1583
@item
1584
   Always fill out the commit log message. Describe in a few lines what you
1585
   changed and why. You can refer to mailing list postings if you fix a
1586
   particular bug. Comments such as "fixed!" or "Changed it." are unacceptable.
1587
@item
1588
   If you apply a patch by someone else, include the name and email address in
1589
   the log message. Since the ffmpeg-cvslog mailing list is publicly
1590
   archived you should add some SPAM protection to the email address. Send an
1591
   answer to ffmpeg-devel (or wherever you got the patch from) saying that
1592
   you applied the patch.
1593
@item
1594
   When applying patches that have been discussed (at length) on the mailing
1595
   list, reference the thread in the log message.
1596
@item
1597
    Do NOT commit to code actively maintained by others without permission.
1598
    Send a patch to ffmpeg-devel instead. If no one answers within a reasonable
1599
    timeframe (12h for build failures and security fixes, 3 days small changes,
1600
    1 week for big patches) then commit your patch if you think it is OK.
1601
    Also note, the maintainer can simply ask for more time to review!
1602
@item
1603
    Subscribe to the ffmpeg-cvslog mailing list. The diffs of all commits
1604
    are sent there and reviewed by all the other developers. Bugs and possible
1605
    improvements or general questions regarding commits are discussed there. We
1606
    expect you to react if problems with your code are uncovered.
1607
@item
1608
    Update the documentation if you change behavior or add features. If you are
1609
    unsure how best to do this, send a patch to ffmpeg-devel, the documentation
1610
    maintainer(s) will review and commit your stuff.
1611
@item
1612
    Try to keep important discussions and requests (also) on the public
1613
    developer mailing list, so that all developers can benefit from them.
1614
@item
1615
    Never write to unallocated memory, never write over the end of arrays,
1616
    always check values read from some untrusted source before using them
1617
    as array index or other risky things.
1618
@item
1619
    Remember to check if you need to bump versions for the specific libav
1620
    parts (libavutil, libavcodec, libavformat) you are changing. You need
1621
    to change the version integer and the version string.
1622
    Incrementing the first component means no backward compatibility to
1623
    previous versions (e.g. removal of a function from the public API).
1624
    Incrementing the second component means backward compatible change
1625
    (e.g. addition of a function to the public API).
1626
    Incrementing the third component means a noteworthy binary compatible
1627
    change (e.g. encoder bug fix that matters for the decoder).
1628
@item
1629
    If you add a new codec, remember to update the changelog, add it to
1630
    the supported codecs table in the documentation and bump the second
1631
    component of the @file{libavcodec} version number appropriately. If
1632
    it has a fourcc, add it to @file{libavformat/avienc.c}, even if it
1633
    is only a decoder.
1634
@item
1635
    Do not change code to hide warnings without ensuring that the underlying
1636
    logic is correct and thus the warning was inappropriate.
1637
@item
1638
    If you add a new file, give it a proper license header. Do not copy and
1639
    paste it from a random place, use an existing file as template.
1640
@end enumerate
1641

    
1642
We think our rules are not too hard. If you have comments, contact us.
1643

    
1644
Note, these rules are mostly borrowed from the MPlayer project.
1645

    
1646
@section Submitting patches
1647

    
1648
First, (@pxref{Coding Rules}) above if you did not yet.
1649

    
1650
When you submit your patch, try to send a unified diff (diff '-up'
1651
option). I cannot read other diffs :-)
1652

    
1653
Also please do not submit patches which contain several unrelated changes.
1654
Split them into individual self-contained patches; this makes reviewing
1655
them much easier.
1656

    
1657
Run the regression tests before submitting a patch so that you can
1658
verify that there are no big problems.
1659

    
1660
Patches should be posted as base64 encoded attachments (or any other
1661
encoding which ensures that the patch will not be trashed during
1662
transmission) to the ffmpeg-devel mailing list, see
1663
@url{http://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel}
1664

    
1665
It also helps quite a bit if you tell us what the patch does (for example
1666
'replaces lrint by lrintf'), and why (for example '*BSD isn't C99 compliant
1667
and has no lrint()')
1668

    
1669
Also please if you send several patches, send each patch as separate mail,
1670
do not attach several unrelated patches to the same mail.
1671

    
1672
@section patch submission checklist
1673

    
1674
@enumerate
1675
@item
1676
    Do the regression tests pass with the patch applied?
1677
@item
1678
    Is the patch a unified diff?
1679
@item
1680
    Is the patch against latest FFmpeg SVN?
1681
@item
1682
    Are you subscribed to ffmpeg-dev?
1683
    (the list is subscribers only due to spam)
1684
@item
1685
    Have you checked that the changes are minimal, so that the same cannot be
1686
    achieved with a smaller patch and/or simpler final code?
1687
@item
1688
    If the change is to speed critical code, did you benchmark it?
1689
@item
1690
    If you did any benchmarks, did you provide them in the mail?
1691
@item
1692
    Have you checked that the patch does not introduce buffer overflows or
1693
    other security issues?
1694
@item
1695
    Is the patch created from the root of the source tree, so it can be
1696
    applied with @code{patch -p0}?
1697
@item
1698
    Does the patch not mix functional and cosmetic changes?
1699
@item
1700
    Did you add tabs or trailing whitespace to the code? Both are forbidden.
1701
@item
1702
    Is the patch attached to the email you send?
1703
@item
1704
    Is the mime type of the patch correct? It should be text/x-diff or
1705
    text/x-patch or at least text/plain and not application/octet-stream.
1706
@item
1707
    If the patch fixes a bug, did you provide a verbose analysis of the bug?
1708
@item
1709
    If the patch fixes a bug, did you provide enough information, including
1710
    a sample, so the bug can be reproduced and the fix can be verified?
1711
    Note please do not attach samples >100k to mails but rather provide a
1712
    URL, you can upload to ftp://upload.mplayerhq.hu
1713
@item
1714
    Did you provide a verbose summary about what the patch does change?
1715
@item
1716
    Did you provide a verbose explanation why it changes things like it does?
1717
@item
1718
    Did you provide a verbose summary of the user visible advantages and
1719
    disadvantages if the patch is applied?
1720
@item
1721
    Did you provide an example so we can verify the new feature added by the
1722
    patch easily?
1723
@item
1724
    If you added a new file, did you insert a license header? It should be
1725
    taken from FFmpeg, not randomly copied and pasted from somewhere else.
1726
@item
1727
    You should maintain alphabetical order in alphabetically ordered lists as
1728
    long as doing so does not break API/ABI compatibility.
1729
@item
1730
    Did you provide a suggestion for a clear commit log message?
1731
@end enumerate
1732

    
1733
@section Patch review process
1734

    
1735
All patches posted to ffmpeg-devel will be reviewed, unless they contain a
1736
clear note that the patch is not for SVN.
1737
Reviews and comments will be posted as replies to the patch on the
1738
mailing list. The patch submitter then has to take care of every comment,
1739
that can be by resubmitting a changed patch or by discussion. Resubmitted
1740
patches will themselves be reviewed like any other patch. If at some point
1741
a patch passes review with no comments then it is approved, that can for
1742
simple and small patches happen immediately while large patches will generally
1743
have to be changed and reviewed many times before they are approved.
1744
After a patch is approved it will be committed to the repository.
1745

    
1746
We will review all submitted patches, but sometimes we are quite busy so
1747
especially for large patches this can take several weeks.
1748

    
1749
When resubmitting patches, please do not make any significant changes
1750
not related to the comments received during review. Such patches will
1751
be rejected. Instead, submit  significant changes or new features as
1752
separate patches.
1753

    
1754
@section Regression tests
1755

    
1756
Before submitting a patch (or committing to the repository), you should at least
1757
test that you did not break anything.
1758

    
1759
The regression tests build a synthetic video stream and a synthetic
1760
audio stream. These are then encoded and decoded with all codecs or
1761
formats. The CRC (or MD5) of each generated file is recorded in a
1762
result file. A 'diff' is launched to compare the reference results and
1763
the result file.
1764

    
1765
The regression tests then go on to test the FFserver code with a
1766
limited set of streams. It is important that this step runs correctly
1767
as well.
1768

    
1769
Run 'make test' to test all the codecs and formats.
1770

    
1771
Run 'make fulltest' to test all the codecs, formats and FFserver.
1772

    
1773
[Of course, some patches may change the results of the regression tests. In
1774
this case, the reference results of the regression tests shall be modified
1775
accordingly].
1776

    
1777
@bye