reference thread: Subject: [FFmpeg-devel] [PATCH] RoQ muxer Date: Wed, 09 May 2007 19:44:21 +0200 Originally committed as revision 8959 to svn://svn.ffmpeg.org/ffmpeg/trunk
		
			
				
	
	
		
			1773 lines
		
	
	
		
			60 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
			
		
		
	
	
			1773 lines
		
	
	
		
			60 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
\input texinfo @c -*- texinfo -*-
 | 
						|
 | 
						|
@settitle FFmpeg Documentation
 | 
						|
@titlepage
 | 
						|
@sp 7
 | 
						|
@center @titlefont{FFmpeg Documentation}
 | 
						|
@sp 3
 | 
						|
@end titlepage
 | 
						|
 | 
						|
 | 
						|
@chapter Introduction
 | 
						|
 | 
						|
FFmpeg is a very fast video and audio converter. It can also grab from
 | 
						|
a live audio/video source.
 | 
						|
 | 
						|
The command line interface is designed to be intuitive, in the sense
 | 
						|
that FFmpeg tries to figure out all parameters that can possibly be
 | 
						|
derived automatically. You usually only have to specify the target
 | 
						|
bitrate you want.
 | 
						|
 | 
						|
FFmpeg can also convert from any sample rate to any other, and resize
 | 
						|
video on the fly with a high quality polyphase filter.
 | 
						|
 | 
						|
@chapter Quick Start
 | 
						|
 | 
						|
@c man begin EXAMPLES
 | 
						|
@section Video and Audio grabbing
 | 
						|
 | 
						|
FFmpeg can grab video and audio from devices given that you specify the input
 | 
						|
format and device.
 | 
						|
 | 
						|
@example
 | 
						|
ffmpeg -f audio_device -i /dev/dsp -f video4linux2 -i /dev/video0 /tmp/out.mpg
 | 
						|
@end example
 | 
						|
 | 
						|
Note that you must activate the right video source and channel before
 | 
						|
launching FFmpeg with any TV viewer such as xawtv
 | 
						|
(@url{http://bytesex.org/xawtv/}) by Gerd Knorr. You also
 | 
						|
have to set the audio recording levels correctly with a
 | 
						|
standard mixer.
 | 
						|
 | 
						|
@section X11 grabbing
 | 
						|
 | 
						|
FFmpeg can grab the X11 display.
 | 
						|
 | 
						|
@example
 | 
						|
ffmpeg -f x11grab -s cif -i :0.0 /tmp/out.mpg
 | 
						|
@end example
 | 
						|
 | 
						|
0.0 is display.screen number of your X11 server, same as
 | 
						|
the DISPLAY environment variable.
 | 
						|
 | 
						|
@example
 | 
						|
ffmpeg -f x11grab -s cif -i :0.0+10,20 /tmp/out.mpg
 | 
						|
@end example
 | 
						|
 | 
						|
0.0 is display.screen number of your X11 server, same as the DISPLAY environment
 | 
						|
variable. 10 is the x-offset and 20 the y-offset for the grabbing.
 | 
						|
 | 
						|
@section Video and Audio file format conversion
 | 
						|
 | 
						|
* FFmpeg can use any supported file format and protocol as input:
 | 
						|
 | 
						|
Examples:
 | 
						|
 | 
						|
* You can use YUV files as input:
 | 
						|
 | 
						|
@example
 | 
						|
ffmpeg -i /tmp/test%d.Y /tmp/out.mpg
 | 
						|
@end example
 | 
						|
 | 
						|
It will use the files:
 | 
						|
@example
 | 
						|
/tmp/test0.Y, /tmp/test0.U, /tmp/test0.V,
 | 
						|
/tmp/test1.Y, /tmp/test1.U, /tmp/test1.V, etc...
 | 
						|
@end example
 | 
						|
 | 
						|
The Y files use twice the resolution of the U and V files. They are
 | 
						|
raw files, without header. They can be generated by all decent video
 | 
						|
decoders. You must specify the size of the image with the @option{-s} option
 | 
						|
if FFmpeg cannot guess it.
 | 
						|
 | 
						|
* You can input from a raw YUV420P file:
 | 
						|
 | 
						|
@example
 | 
						|
ffmpeg -i /tmp/test.yuv /tmp/out.avi
 | 
						|
@end example
 | 
						|
 | 
						|
test.yuv is a file containing raw YUV planar data. Each frame is composed
 | 
						|
of the Y plane followed by the U and V planes at half vertical and
 | 
						|
horizontal resolution.
 | 
						|
 | 
						|
* You can output to a raw YUV420P file:
 | 
						|
 | 
						|
@example
 | 
						|
ffmpeg -i mydivx.avi hugefile.yuv
 | 
						|
@end example
 | 
						|
 | 
						|
* You can set several input files and output files:
 | 
						|
 | 
						|
@example
 | 
						|
ffmpeg -i /tmp/a.wav -s 640x480 -i /tmp/a.yuv /tmp/a.mpg
 | 
						|
@end example
 | 
						|
 | 
						|
Converts the audio file a.wav and the raw YUV video file a.yuv
 | 
						|
to MPEG file a.mpg.
 | 
						|
 | 
						|
* You can also do audio and video conversions at the same time:
 | 
						|
 | 
						|
@example
 | 
						|
ffmpeg -i /tmp/a.wav -ar 22050 /tmp/a.mp2
 | 
						|
@end example
 | 
						|
 | 
						|
Converts a.wav to MPEG audio at 22050Hz sample rate.
 | 
						|
 | 
						|
* You can encode to several formats at the same time and define a
 | 
						|
mapping from input stream to output streams:
 | 
						|
 | 
						|
@example
 | 
						|
ffmpeg -i /tmp/a.wav -ab 64k /tmp/a.mp2 -ab 128k /tmp/b.mp2 -map 0:0 -map 0:0
 | 
						|
@end example
 | 
						|
 | 
						|
Converts a.wav to a.mp2 at 64 kbits and to b.mp2 at 128 kbits. '-map
 | 
						|
file:index' specifies which input stream is used for each output
 | 
						|
stream, in the order of the definition of output streams.
 | 
						|
 | 
						|
* You can transcode decrypted VOBs
 | 
						|
 | 
						|
@example
 | 
						|
ffmpeg -i snatch_1.vob -f avi -vcodec mpeg4 -b 800k -g 300 -bf 2 -acodec mp3 -ab 128k snatch.avi
 | 
						|
@end example
 | 
						|
 | 
						|
This is a typical DVD ripping example; the input is a VOB file, the
 | 
						|
output an AVI file with MPEG-4 video and MP3 audio. Note that in this
 | 
						|
command we use B-frames so the MPEG-4 stream is DivX5 compatible, and
 | 
						|
GOP size is 300 which means one intra frame every 10 seconds for 29.97fps
 | 
						|
input video. Furthermore, the audio stream is MP3-encoded so you need
 | 
						|
to enable LAME support by passing @code{--enable-mp3lame} to configure.
 | 
						|
The mapping is particularly useful for DVD transcoding
 | 
						|
to get the desired audio language.
 | 
						|
 | 
						|
NOTE: To see the supported input formats, use @code{ffmpeg -formats}.
 | 
						|
@c man end
 | 
						|
 | 
						|
@chapter Invocation
 | 
						|
 | 
						|
@section Syntax
 | 
						|
 | 
						|
The generic syntax is:
 | 
						|
 | 
						|
@example
 | 
						|
@c man begin SYNOPSIS
 | 
						|
ffmpeg [[infile options][@option{-i} @var{infile}]]... @{[outfile options] @var{outfile}@}...
 | 
						|
@c man end
 | 
						|
@end example
 | 
						|
@c man begin DESCRIPTION
 | 
						|
As a general rule, options are applied to the next specified
 | 
						|
file. Therefore, order is important, and you can have the same
 | 
						|
option on the command line multiple times. Each occurrence is
 | 
						|
then applied to the next input or output file.
 | 
						|
 | 
						|
* To set the video bitrate of the output file to 64kbit/s:
 | 
						|
@example
 | 
						|
ffmpeg -i input.avi -b 64k output.avi
 | 
						|
@end example
 | 
						|
 | 
						|
* To force the frame rate of the input and output file to 24 fps:
 | 
						|
@example
 | 
						|
ffmpeg -r 24 -i input.avi output.avi
 | 
						|
@end example
 | 
						|
 | 
						|
* To force the frame rate of the output file to 24 fps:
 | 
						|
@example
 | 
						|
ffmpeg -i input.avi -r 24 output.avi
 | 
						|
@end example
 | 
						|
 | 
						|
* To force the frame rate of input file to 1 fps and the output file to 24 fps:
 | 
						|
@example
 | 
						|
ffmpeg -r 1 -i input.avi -r 24 output.avi
 | 
						|
@end example
 | 
						|
 | 
						|
The format option may be needed for raw input files.
 | 
						|
 | 
						|
By default, FFmpeg tries to convert as losslessly as possible: It
 | 
						|
uses the same audio and video parameters for the outputs as the one
 | 
						|
specified for the inputs.
 | 
						|
@c man end
 | 
						|
 | 
						|
@c man begin OPTIONS
 | 
						|
@section Main options
 | 
						|
 | 
						|
@table @option
 | 
						|
@item -L
 | 
						|
Show license.
 | 
						|
 | 
						|
@item -h
 | 
						|
Show help.
 | 
						|
 | 
						|
@item -version
 | 
						|
Show version.
 | 
						|
 | 
						|
@item -formats
 | 
						|
Show available formats, codecs, protocols, ...
 | 
						|
 | 
						|
@item -f fmt
 | 
						|
Force format.
 | 
						|
 | 
						|
@item -i filename
 | 
						|
input filename
 | 
						|
 | 
						|
@item -y
 | 
						|
Overwrite output files.
 | 
						|
 | 
						|
@item -t duration
 | 
						|
Set the recording time in seconds.
 | 
						|
@code{hh:mm:ss[.xxx]} syntax is also supported.
 | 
						|
 | 
						|
@item -fs limit_size
 | 
						|
Set the file size limit.
 | 
						|
 | 
						|
@item -ss position
 | 
						|
Seek to given time position in seconds.
 | 
						|
@code{hh:mm:ss[.xxx]} syntax is also supported.
 | 
						|
 | 
						|
@item -itsoffset offset
 | 
						|
Set the input time offset in seconds.
 | 
						|
@code{[-]hh:mm:ss[.xxx]} syntax is also supported.
 | 
						|
This option affects all the input files that follow it.
 | 
						|
The offset is added to the timestamps of the input files.
 | 
						|
Specifying a positive offset means that the corresponding
 | 
						|
streams are delayed by 'offset' seconds.
 | 
						|
 | 
						|
@item -title string
 | 
						|
Set the title.
 | 
						|
 | 
						|
@item -timestamp time
 | 
						|
Set the timestamp.
 | 
						|
 | 
						|
@item -author string
 | 
						|
Set the author.
 | 
						|
 | 
						|
@item -copyright string
 | 
						|
Set the copyright.
 | 
						|
 | 
						|
@item -comment string
 | 
						|
Set the comment.
 | 
						|
 | 
						|
@item -album string
 | 
						|
Set the album.
 | 
						|
 | 
						|
@item -track number
 | 
						|
Set the track.
 | 
						|
 | 
						|
@item -year number
 | 
						|
Set the year.
 | 
						|
 | 
						|
@item -v verbose
 | 
						|
Control amount of logging.
 | 
						|
 | 
						|
@item -target type
 | 
						|
Specify target file type ("vcd", "svcd", "dvd", "dv", "dv50", "pal-vcd",
 | 
						|
"ntsc-svcd", ... ). All the format options (bitrate, codecs,
 | 
						|
buffer sizes) are then set automatically. You can just type:
 | 
						|
 | 
						|
@example
 | 
						|
ffmpeg -i myfile.avi -target vcd /tmp/vcd.mpg
 | 
						|
@end example
 | 
						|
 | 
						|
Nevertheless you can specify additional options as long as you know
 | 
						|
they do not conflict with the standard, as in:
 | 
						|
 | 
						|
@example
 | 
						|
ffmpeg -i myfile.avi -target vcd -bf 2 /tmp/vcd.mpg
 | 
						|
@end example
 | 
						|
 | 
						|
@item -dframes number
 | 
						|
Set the number of data frames to record.
 | 
						|
 | 
						|
@item -scodec codec
 | 
						|
Force subtitle codec ('copy' to copy stream).
 | 
						|
 | 
						|
@item -newsubtitle
 | 
						|
Add a new subtitle stream to the current output stream.
 | 
						|
 | 
						|
@item -slang code
 | 
						|
Set the ISO 639 language code (3 letters) of the current subtitle stream.
 | 
						|
 | 
						|
@end table
 | 
						|
 | 
						|
@section Video Options
 | 
						|
 | 
						|
@table @option
 | 
						|
@item -b bitrate
 | 
						|
Set the video bitrate in bit/s (default = 200 kb/s).
 | 
						|
@item -vframes number
 | 
						|
Set the number of video frames to record.
 | 
						|
@item -r fps
 | 
						|
Set frame rate (Hz value, fraction or abbreviation), (default = 25).
 | 
						|
@item -s size
 | 
						|
Set frame size. The format is @samp{wxh} (ffserver default = 160x128, ffmpeg default = same as source).
 | 
						|
The following abbreviations are recognized:
 | 
						|
@table @samp
 | 
						|
@item sqcif
 | 
						|
128x96
 | 
						|
@item qcif
 | 
						|
176x144
 | 
						|
@item cif
 | 
						|
352x288
 | 
						|
@item 4cif
 | 
						|
704x576
 | 
						|
@item qqvga
 | 
						|
160x120
 | 
						|
@item qvga
 | 
						|
320x240
 | 
						|
@item vga
 | 
						|
640x480
 | 
						|
@item svga
 | 
						|
800x600
 | 
						|
@item xga
 | 
						|
1024x768
 | 
						|
@item uxga
 | 
						|
1600x1200
 | 
						|
@item qxga
 | 
						|
2048x1536
 | 
						|
@item sxga
 | 
						|
1280x1024
 | 
						|
@item qsxga
 | 
						|
2560x2048
 | 
						|
@item hsxga
 | 
						|
5120x4096
 | 
						|
@item wvga
 | 
						|
852x480
 | 
						|
@item wxga
 | 
						|
1366x768
 | 
						|
@item wsxga
 | 
						|
1600x1024
 | 
						|
@item wuxga
 | 
						|
1920x1200
 | 
						|
@item woxga
 | 
						|
2560x1600
 | 
						|
@item wqsxga
 | 
						|
3200x2048
 | 
						|
@item wquxga
 | 
						|
3840x2400
 | 
						|
@item whsxga
 | 
						|
6400x4096
 | 
						|
@item whuxga
 | 
						|
7680x4800
 | 
						|
@item cga
 | 
						|
320x200
 | 
						|
@item ega
 | 
						|
640x350
 | 
						|
@item hd480
 | 
						|
852x480
 | 
						|
@item hd720
 | 
						|
1280x720
 | 
						|
@item hd1080
 | 
						|
1920x1080
 | 
						|
@end table
 | 
						|
 | 
						|
@item -aspect aspect
 | 
						|
Set aspect ratio (4:3, 16:9 or 1.3333, 1.7777).
 | 
						|
@item -croptop size
 | 
						|
Set top crop band size (in pixels).
 | 
						|
@item -cropbottom size
 | 
						|
Set bottom crop band size (in pixels).
 | 
						|
@item -cropleft size
 | 
						|
Set left crop band size (in pixels).
 | 
						|
@item -cropright size
 | 
						|
Set right crop band size (in pixels).
 | 
						|
@item -padtop size
 | 
						|
Set top pad band size (in pixels).
 | 
						|
@item -padbottom size
 | 
						|
Set bottom pad band size (in pixels).
 | 
						|
@item -padleft size
 | 
						|
Set left pad band size (in pixels).
 | 
						|
@item -padright size
 | 
						|
Set right pad band size (in pixels).
 | 
						|
@item -padcolor (hex color)
 | 
						|
Set color of padded bands. The value for padcolor is expressed
 | 
						|
as a six digit hexadecimal number where the first two digits
 | 
						|
represent red, the middle two digits green and last two digits
 | 
						|
blue (default = 000000 (black)).
 | 
						|
@item -vn
 | 
						|
Disable video recording.
 | 
						|
@item -bt tolerance
 | 
						|
Set video bitrate tolerance (in bit/s).
 | 
						|
@item -maxrate bitrate
 | 
						|
Set max video bitrate tolerance (in bit/s).
 | 
						|
@item -minrate bitrate
 | 
						|
Set min video bitrate tolerance (in bit/s).
 | 
						|
@item -bufsize size
 | 
						|
Set rate control buffer size (in bits).
 | 
						|
@item -vcodec codec
 | 
						|
Force video codec to @var{codec}. Use the @code{copy} special value to
 | 
						|
tell that the raw codec data must be copied as is.
 | 
						|
@item -sameq
 | 
						|
Use same video quality as source (implies VBR).
 | 
						|
 | 
						|
@item -pass n
 | 
						|
Select the pass number (1 or 2). It is useful to do two pass
 | 
						|
encoding. The statistics of the video are recorded in the first
 | 
						|
pass and the video is generated at the exact requested bitrate
 | 
						|
in the second pass.
 | 
						|
 | 
						|
@item -passlogfile file
 | 
						|
Set two pass logfile name to @var{file}.
 | 
						|
 | 
						|
@item -newvideo
 | 
						|
Add a new video stream to the current output stream.
 | 
						|
 | 
						|
@end table
 | 
						|
 | 
						|
@section Advanced Video Options
 | 
						|
 | 
						|
@table @option
 | 
						|
@item -pix_fmt format
 | 
						|
Set pixel format.
 | 
						|
@item -g gop_size
 | 
						|
Set the group of pictures size.
 | 
						|
@item -intra
 | 
						|
Use only intra frames.
 | 
						|
@item -vdt n
 | 
						|
Discard threshold.
 | 
						|
@item -qscale q
 | 
						|
Use fixed video quantizer scale (VBR).
 | 
						|
@item -qmin q
 | 
						|
minimum video quantizer scale (VBR)
 | 
						|
@item -qmax q
 | 
						|
maximum video quantizer scale (VBR)
 | 
						|
@item -qdiff q
 | 
						|
maximum difference between the quantizer scales (VBR)
 | 
						|
@item -qblur blur
 | 
						|
video quantizer scale blur (VBR)
 | 
						|
@item -qcomp compression
 | 
						|
video quantizer scale compression (VBR)
 | 
						|
 | 
						|
@item -lmin lambda
 | 
						|
minimum video lagrange factor (VBR)
 | 
						|
@item -lmax lambda
 | 
						|
max video lagrange factor (VBR)
 | 
						|
@item -mblmin lambda
 | 
						|
minimum macroblock quantizer scale (VBR)
 | 
						|
@item -mblmax lambda
 | 
						|
maximum macroblock quantizer scale (VBR)
 | 
						|
 | 
						|
These four options (lmin, lmax, mblmin, mblmax) use 'lambda' units,
 | 
						|
but you may use the QP2LAMBDA constant to easily convert from 'q' units:
 | 
						|
@example
 | 
						|
ffmpeg -i src.ext -lmax 21*QP2LAMBDA dst.ext
 | 
						|
@end example
 | 
						|
 | 
						|
@item -rc_init_cplx complexity
 | 
						|
initial complexity for single pass encoding
 | 
						|
@item -b_qfactor factor
 | 
						|
qp factor between P- and B-frames
 | 
						|
@item -i_qfactor factor
 | 
						|
qp factor between P- and I-frames
 | 
						|
@item -b_qoffset offset
 | 
						|
qp offset between P- and B-frames
 | 
						|
@item -i_qoffset offset
 | 
						|
qp offset between P- and I-frames
 | 
						|
@item -rc_eq equation
 | 
						|
Set rate control equation (@pxref{FFmpeg formula
 | 
						|
evaluator}) (default = @code{tex^qComp}).
 | 
						|
@item -rc_override override
 | 
						|
rate control override for specific intervals
 | 
						|
@item -me method
 | 
						|
Set motion estimation method to @var{method}.
 | 
						|
Available methods are (from lowest to best quality):
 | 
						|
@table @samp
 | 
						|
@item zero
 | 
						|
Try just the (0, 0) vector.
 | 
						|
@item phods
 | 
						|
@item log
 | 
						|
@item x1
 | 
						|
@item epzs
 | 
						|
(default method)
 | 
						|
@item full
 | 
						|
exhaustive search (slow and marginally better than epzs)
 | 
						|
@end table
 | 
						|
 | 
						|
@item -dct_algo algo
 | 
						|
Set DCT algorithm to @var{algo}. Available values are:
 | 
						|
@table @samp
 | 
						|
@item 0
 | 
						|
FF_DCT_AUTO (default)
 | 
						|
@item 1
 | 
						|
FF_DCT_FASTINT
 | 
						|
@item 2
 | 
						|
FF_DCT_INT
 | 
						|
@item 3
 | 
						|
FF_DCT_MMX
 | 
						|
@item 4
 | 
						|
FF_DCT_MLIB
 | 
						|
@item 5
 | 
						|
FF_DCT_ALTIVEC
 | 
						|
@end table
 | 
						|
 | 
						|
@item -idct_algo algo
 | 
						|
Set IDCT algorithm to @var{algo}. Available values are:
 | 
						|
@table @samp
 | 
						|
@item 0
 | 
						|
FF_IDCT_AUTO (default)
 | 
						|
@item 1
 | 
						|
FF_IDCT_INT
 | 
						|
@item 2
 | 
						|
FF_IDCT_SIMPLE
 | 
						|
@item 3
 | 
						|
FF_IDCT_SIMPLEMMX
 | 
						|
@item 4
 | 
						|
FF_IDCT_LIBMPEG2MMX
 | 
						|
@item 5
 | 
						|
FF_IDCT_PS2
 | 
						|
@item 6
 | 
						|
FF_IDCT_MLIB
 | 
						|
@item 7
 | 
						|
FF_IDCT_ARM
 | 
						|
@item 8
 | 
						|
FF_IDCT_ALTIVEC
 | 
						|
@item 9
 | 
						|
FF_IDCT_SH4
 | 
						|
@item 10
 | 
						|
FF_IDCT_SIMPLEARM
 | 
						|
@end table
 | 
						|
 | 
						|
@item -er n
 | 
						|
Set error resilience to @var{n}.
 | 
						|
@table @samp
 | 
						|
@item 1
 | 
						|
FF_ER_CAREFUL (default)
 | 
						|
@item 2
 | 
						|
FF_ER_COMPLIANT
 | 
						|
@item 3
 | 
						|
FF_ER_AGGRESSIVE
 | 
						|
@item 4
 | 
						|
FF_ER_VERY_AGGRESSIVE
 | 
						|
@end table
 | 
						|
 | 
						|
@item -ec bit_mask
 | 
						|
Set error concealment to @var{bit_mask}. @var{bit_mask} is a bit mask of
 | 
						|
the following values:
 | 
						|
@table @samp
 | 
						|
@item 1
 | 
						|
FF_EC_GUESS_MVS (default = enabled)
 | 
						|
@item 2
 | 
						|
FF_EC_DEBLOCK (default = enabled)
 | 
						|
@end table
 | 
						|
 | 
						|
@item -bf frames
 | 
						|
Use 'frames' B-frames (supported for MPEG-1, MPEG-2 and MPEG-4).
 | 
						|
@item -mbd mode
 | 
						|
macroblock decision
 | 
						|
@table @samp
 | 
						|
@item 0
 | 
						|
FF_MB_DECISION_SIMPLE: Use mb_cmp (cannot change it yet in FFmpeg).
 | 
						|
@item 1
 | 
						|
FF_MB_DECISION_BITS: Choose the one which needs the fewest bits.
 | 
						|
@item 2
 | 
						|
FF_MB_DECISION_RD: rate distortion
 | 
						|
@end table
 | 
						|
 | 
						|
@item -4mv
 | 
						|
Use four motion vector by macroblock (MPEG-4 only).
 | 
						|
@item -part
 | 
						|
Use data partitioning (MPEG-4 only).
 | 
						|
@item -bug param
 | 
						|
Work around encoder bugs that are not auto-detected.
 | 
						|
@item -strict strictness
 | 
						|
How strictly to follow the standards.
 | 
						|
@item -aic
 | 
						|
Enable Advanced intra coding (h263+).
 | 
						|
@item -umv
 | 
						|
Enable Unlimited Motion Vector (h263+)
 | 
						|
 | 
						|
@item -deinterlace
 | 
						|
Deinterlace pictures.
 | 
						|
@item -ilme
 | 
						|
Force interlacing support in encoder (MPEG-2 and MPEG-4 only).
 | 
						|
Use this option if your input file is interlaced and you want
 | 
						|
to keep the interlaced format for minimum losses.
 | 
						|
The alternative is to deinterlace the input stream with
 | 
						|
@option{-deinterlace}, but deinterlacing introduces losses.
 | 
						|
@item -psnr
 | 
						|
Calculate PSNR of compressed frames.
 | 
						|
@item -vstats
 | 
						|
Dump video coding statistics to @file{vstats_HHMMSS.log}.
 | 
						|
@item -vstats_file file
 | 
						|
Dump video coding statistics to @var{file}.
 | 
						|
@item -vhook module
 | 
						|
Insert video processing @var{module}. @var{module} contains the module
 | 
						|
name and its parameters separated by spaces.
 | 
						|
@item -top n
 | 
						|
top=1/bottom=0/auto=-1 field first
 | 
						|
@item -dc precision
 | 
						|
Intra_dc_precision.
 | 
						|
@item -vtag fourcc/tag
 | 
						|
Force video tag/fourcc.
 | 
						|
@item -qphist
 | 
						|
Show QP histogram.
 | 
						|
@item -vbsf bitstream filter
 | 
						|
Bitstream filters available are "dump_extra", "remove_extra", "noise".
 | 
						|
@end table
 | 
						|
 | 
						|
@section Audio Options
 | 
						|
 | 
						|
@table @option
 | 
						|
@item -aframes number
 | 
						|
Set the number of audio frames to record.
 | 
						|
@item -ar freq
 | 
						|
Set the audio sampling frequency (default = 44100 Hz).
 | 
						|
@item -ab bitrate
 | 
						|
Set the audio bitrate in bit/s (default = 64k).
 | 
						|
@item -ac channels
 | 
						|
Set the number of audio channels (default = 1).
 | 
						|
@item -an
 | 
						|
Disable audio recording.
 | 
						|
@item -acodec codec
 | 
						|
Force audio codec to @var{codec}. Use the @code{copy} special value to
 | 
						|
specify that the raw codec data must be copied as is.
 | 
						|
@item -newaudio
 | 
						|
Add a new audio track to the output file. If you want to specify parameters,
 | 
						|
do so before @code{-newaudio} (@code{-acodec}, @code{-ab}, etc..).
 | 
						|
 | 
						|
Mapping will be done automatically, if the number of output streams is equal to
 | 
						|
the number of input streams, else it will pick the first one that matches. You
 | 
						|
can override the mapping using @code{-map} as usual.
 | 
						|
 | 
						|
Example:
 | 
						|
@example
 | 
						|
ffmpeg -i file.mpg -vcodec copy -acodec ac3 -ab 384k test.mpg -acodec mp2 -ab 192k -newaudio
 | 
						|
@end example
 | 
						|
@item -alang code
 | 
						|
Set the ISO 639 language code (3 letters) of the current audio stream.
 | 
						|
@end table
 | 
						|
 | 
						|
@section Advanced Audio options:
 | 
						|
 | 
						|
@table @option
 | 
						|
@item -atag fourcc/tag
 | 
						|
Force audio tag/fourcc.
 | 
						|
@item -absf bitstream filter
 | 
						|
Bitstream filters available are "dump_extra", "remove_extra", "noise", "mp3comp", "mp3decomp".
 | 
						|
@end table
 | 
						|
 | 
						|
@section Subtitle options:
 | 
						|
 | 
						|
@table @option
 | 
						|
@item -scodec codec
 | 
						|
Force subtitle codec ('copy' to copy stream).
 | 
						|
@item -newsubtitle
 | 
						|
Add a new subtitle stream to the current output stream.
 | 
						|
@item -slang code
 | 
						|
Set the ISO 639 language code (3 letters) of the current subtitle stream.
 | 
						|
@end table
 | 
						|
 | 
						|
@section Audio/Video grab options
 | 
						|
 | 
						|
@table @option
 | 
						|
@item -vc channel
 | 
						|
Set video grab channel (DV1394 only).
 | 
						|
@item -tvstd standard
 | 
						|
Set television standard (NTSC, PAL (SECAM)).
 | 
						|
@item -isync
 | 
						|
Synchronize read on input.
 | 
						|
@end table
 | 
						|
 | 
						|
@section Advanced options
 | 
						|
 | 
						|
@table @option
 | 
						|
@item -map input stream id[:input stream id]
 | 
						|
Set stream mapping from input streams to output streams.
 | 
						|
Just enumerate the input streams in the order you want them in the output.
 | 
						|
[input stream id] sets the (input) stream to sync against.
 | 
						|
@item -map_meta_data outfile:infile
 | 
						|
Set meta data information of outfile from infile.
 | 
						|
@item -debug
 | 
						|
Print specific debug info.
 | 
						|
@item -benchmark
 | 
						|
Add timings for benchmarking.
 | 
						|
@item -dump
 | 
						|
Dump each input packet.
 | 
						|
@item -hex
 | 
						|
When dumping packets, also dump the payload.
 | 
						|
@item -bitexact
 | 
						|
Only use bit exact algorithms (for codec testing).
 | 
						|
@item -ps size
 | 
						|
Set packet size in bits.
 | 
						|
@item -re
 | 
						|
Read input at native frame rate. Mainly used to simulate a grab device.
 | 
						|
@item -loop_input
 | 
						|
Loop over the input stream. Currently it works only for image
 | 
						|
streams. This option is used for automatic FFserver testing.
 | 
						|
@item -loop_output number_of_times
 | 
						|
Repeatedly loop output for formats that support looping such as animated GIF
 | 
						|
(0 will loop the output infinitely).
 | 
						|
@item -threads count
 | 
						|
Thread count.
 | 
						|
@item -vsync parameter
 | 
						|
Video sync method. Video will be stretched/squeezed to match the timestamps,
 | 
						|
it is done by duplicating and dropping frames. With -map you can select from
 | 
						|
which stream the timestamps should be taken. You can leave either video or
 | 
						|
audio unchanged and sync the remaining stream(s) to the unchanged one.
 | 
						|
@item -async samples_per_second
 | 
						|
Audio sync method. "Stretches/squeezes" the audio stream to match the timestamps,
 | 
						|
the parameter is the maximum samples per second by which the audio is changed.
 | 
						|
-async 1 is a special case where only the start of the audio stream is corrected
 | 
						|
without any later correction.
 | 
						|
@end table
 | 
						|
 | 
						|
@node FFmpeg formula evaluator
 | 
						|
@section FFmpeg formula evaluator
 | 
						|
 | 
						|
When evaluating a rate control string, FFmpeg uses an internal formula
 | 
						|
evaluator.
 | 
						|
 | 
						|
The following binary operators are available: @code{+}, @code{-},
 | 
						|
@code{*}, @code{/}, @code{^}.
 | 
						|
 | 
						|
The following unary operators are available: @code{+}, @code{-},
 | 
						|
@code{(...)}.
 | 
						|
 | 
						|
The following functions are available:
 | 
						|
@table @var
 | 
						|
@item sinh(x)
 | 
						|
@item cosh(x)
 | 
						|
@item tanh(x)
 | 
						|
@item sin(x)
 | 
						|
@item cos(x)
 | 
						|
@item tan(x)
 | 
						|
@item exp(x)
 | 
						|
@item log(x)
 | 
						|
@item squish(x)
 | 
						|
@item gauss(x)
 | 
						|
@item abs(x)
 | 
						|
@item max(x, y)
 | 
						|
@item min(x, y)
 | 
						|
@item gt(x, y)
 | 
						|
@item lt(x, y)
 | 
						|
@item eq(x, y)
 | 
						|
@item bits2qp(bits)
 | 
						|
@item qp2bits(qp)
 | 
						|
@end table
 | 
						|
 | 
						|
The following constants are available:
 | 
						|
@table @var
 | 
						|
@item PI
 | 
						|
@item E
 | 
						|
@item iTex
 | 
						|
@item pTex
 | 
						|
@item tex
 | 
						|
@item mv
 | 
						|
@item fCode
 | 
						|
@item iCount
 | 
						|
@item mcVar
 | 
						|
@item var
 | 
						|
@item isI
 | 
						|
@item isP
 | 
						|
@item isB
 | 
						|
@item avgQP
 | 
						|
@item qComp
 | 
						|
@item avgIITex
 | 
						|
@item avgPITex
 | 
						|
@item avgPPTex
 | 
						|
@item avgBPTex
 | 
						|
@item avgTex
 | 
						|
@end table
 | 
						|
 | 
						|
@c man end
 | 
						|
 | 
						|
@ignore
 | 
						|
 | 
						|
@setfilename ffmpeg
 | 
						|
@settitle FFmpeg video converter
 | 
						|
 | 
						|
@c man begin SEEALSO
 | 
						|
ffserver(1), ffplay(1) and the HTML documentation of @file{ffmpeg}.
 | 
						|
@c man end
 | 
						|
 | 
						|
@c man begin AUTHOR
 | 
						|
Fabrice Bellard
 | 
						|
@c man end
 | 
						|
 | 
						|
@end ignore
 | 
						|
 | 
						|
@section Protocols
 | 
						|
 | 
						|
The filename can be @file{-} to read from standard input or to write
 | 
						|
to standard output.
 | 
						|
 | 
						|
FFmpeg also handles many protocols specified with an URL syntax.
 | 
						|
 | 
						|
Use 'ffmpeg -formats' to see a list of the supported protocols.
 | 
						|
 | 
						|
The protocol @code{http:} is currently used only to communicate with
 | 
						|
FFserver (see the FFserver documentation). When FFmpeg will be a
 | 
						|
video player it will also be used for streaming :-)
 | 
						|
 | 
						|
@chapter Tips
 | 
						|
 | 
						|
@itemize
 | 
						|
@item For streaming at very low bitrate application, use a low frame rate
 | 
						|
and a small GOP size. This is especially true for RealVideo where
 | 
						|
the Linux player does not seem to be very fast, so it can miss
 | 
						|
frames. An example is:
 | 
						|
 | 
						|
@example
 | 
						|
ffmpeg -g 3 -r 3 -t 10 -b 50k -s qcif -f rv10 /tmp/b.rm
 | 
						|
@end example
 | 
						|
 | 
						|
@item  The parameter 'q' which is displayed while encoding is the current
 | 
						|
quantizer. The value 1 indicates that a very good quality could
 | 
						|
be achieved. The value 31 indicates the worst quality. If q=31 appears
 | 
						|
too often, it means that the encoder cannot compress enough to meet
 | 
						|
your bitrate. You must either increase the bitrate, decrease the
 | 
						|
frame rate or decrease the frame size.
 | 
						|
 | 
						|
@item If your computer is not fast enough, you can speed up the
 | 
						|
compression at the expense of the compression ratio. You can use
 | 
						|
'-me zero' to speed up motion estimation, and '-intra' to disable
 | 
						|
motion estimation completely (you have only I-frames, which means it
 | 
						|
is about as good as JPEG compression).
 | 
						|
 | 
						|
@item To have very low audio bitrates, reduce the sampling frequency
 | 
						|
(down to 22050 kHz for MPEG audio, 22050 or 11025 for AC3).
 | 
						|
 | 
						|
@item To have a constant quality (but a variable bitrate), use the option
 | 
						|
'-qscale n' when 'n' is between 1 (excellent quality) and 31 (worst
 | 
						|
quality).
 | 
						|
 | 
						|
@item When converting video files, you can use the '-sameq' option which
 | 
						|
uses the same quality factor in the encoder as in the decoder.
 | 
						|
It allows almost lossless encoding.
 | 
						|
 | 
						|
@end itemize
 | 
						|
 | 
						|
 | 
						|
@chapter external libraries
 | 
						|
 | 
						|
FFmpeg can be hooked up with a number of external libraries to add support
 | 
						|
for more formats. None of them are used by default, their use has to be
 | 
						|
explicitly requested by passing the appropriate flags to @file{./configure}.
 | 
						|
 | 
						|
@section AMR
 | 
						|
 | 
						|
AMR comes in two different flavors, WB and NB. FFmpeg can make use of the
 | 
						|
AMR WB (floating-point mode) and the AMR NB (floating-point mode) reference
 | 
						|
decoders and encoders.
 | 
						|
 | 
						|
Go to @url{http://www.penguin.cz/~utx/amr} and follow the instructions for
 | 
						|
installing the libraries. Then pass @code{--enable-amr-nb} and/or
 | 
						|
@code{--enable-amr-wb} to configure to enable the libraries.
 | 
						|
 | 
						|
 | 
						|
@chapter Supported File Formats and Codecs
 | 
						|
 | 
						|
You can use the @code{-formats} option to have an exhaustive list.
 | 
						|
 | 
						|
@section File Formats
 | 
						|
 | 
						|
FFmpeg supports the following file formats through the @code{libavformat}
 | 
						|
library:
 | 
						|
 | 
						|
@multitable @columnfractions .4 .1 .1 .4
 | 
						|
@item Supported File Format @tab Encoding @tab Decoding @tab Comments
 | 
						|
@item MPEG audio @tab X @tab X
 | 
						|
@item MPEG-1 systems @tab X  @tab  X
 | 
						|
@tab muxed audio and video
 | 
						|
@item MPEG-2 PS @tab X  @tab  X
 | 
						|
@tab also known as @code{VOB} file
 | 
						|
@item MPEG-2 TS @tab    @tab  X
 | 
						|
@tab also known as DVB Transport Stream
 | 
						|
@item ASF@tab X @tab X
 | 
						|
@item AVI@tab X @tab X
 | 
						|
@item WAV@tab X @tab X
 | 
						|
@item Macromedia Flash@tab X @tab X
 | 
						|
@tab Only embedded audio is decoded.
 | 
						|
@item FLV              @tab  X @tab X
 | 
						|
@tab Macromedia Flash video files
 | 
						|
@item Real Audio and Video @tab X @tab X
 | 
						|
@item Raw AC3 @tab X  @tab  X
 | 
						|
@item Raw MJPEG @tab X  @tab  X
 | 
						|
@item Raw MPEG video @tab X  @tab  X
 | 
						|
@item Raw PCM8/16 bits, mulaw/Alaw@tab X  @tab  X
 | 
						|
@item Raw CRI ADX audio @tab X  @tab  X
 | 
						|
@item Raw Shorten audio @tab    @tab  X
 | 
						|
@item SUN AU format @tab X  @tab  X
 | 
						|
@item NUT @tab X @tab X @tab NUT Open Container Format
 | 
						|
@item QuickTime        @tab X @tab  X
 | 
						|
@item MPEG-4           @tab X @tab  X
 | 
						|
@tab MPEG-4 is a variant of QuickTime.
 | 
						|
@item Raw MPEG4 video  @tab  X @tab  X
 | 
						|
@item DV               @tab  X @tab  X
 | 
						|
@item 4xm              @tab    @tab X
 | 
						|
@tab 4X Technologies format, used in some games.
 | 
						|
@item Playstation STR  @tab    @tab X
 | 
						|
@item Id RoQ           @tab X  @tab X
 | 
						|
@tab Used in Quake III, Jedi Knight 2, other computer games.
 | 
						|
@item Interplay MVE    @tab    @tab X
 | 
						|
@tab Format used in various Interplay computer games.
 | 
						|
@item WC3 Movie        @tab    @tab X
 | 
						|
@tab Multimedia format used in Origin's Wing Commander III computer game.
 | 
						|
@item Sega FILM/CPK    @tab    @tab X
 | 
						|
@tab Used in many Sega Saturn console games.
 | 
						|
@item Westwood Studios VQA/AUD  @tab    @tab X
 | 
						|
@tab Multimedia formats used in Westwood Studios games.
 | 
						|
@item Id Cinematic (.cin) @tab    @tab X
 | 
						|
@tab Used in Quake II.
 | 
						|
@item FLIC format      @tab    @tab X
 | 
						|
@tab .fli/.flc files
 | 
						|
@item Sierra VMD       @tab    @tab X
 | 
						|
@tab Used in Sierra CD-ROM games.
 | 
						|
@item Sierra Online    @tab    @tab X
 | 
						|
@tab .sol files used in Sierra Online games.
 | 
						|
@item Matroska         @tab    @tab X
 | 
						|
@item Electronic Arts Multimedia    @tab    @tab X
 | 
						|
@tab Used in various EA games; files have extensions like WVE and UV2.
 | 
						|
@item Nullsoft Video (NSV) format @tab    @tab X
 | 
						|
@item ADTS AAC audio @tab X @tab X
 | 
						|
@item Creative VOC @tab X @tab X @tab Created for the Sound Blaster Pro.
 | 
						|
@item American Laser Games MM  @tab    @tab X
 | 
						|
@tab Multimedia format used in games like Mad Dog McCree
 | 
						|
@item AVS @tab    @tab X
 | 
						|
@tab Multimedia format used by the Creature Shock game.
 | 
						|
@item Smacker @tab    @tab X
 | 
						|
@tab Multimedia format used by many games.
 | 
						|
@item GXF @tab  X @tab X
 | 
						|
@tab General eXchange Format SMPTE 360M, used by Thomson Grass Valley playout servers.
 | 
						|
@item CIN @tab    @tab X
 | 
						|
@tab Multimedia format used by Delphine Software games.
 | 
						|
@item MXF @tab    @tab X
 | 
						|
@tab Material eXchange Format SMPTE 377M, used by D-Cinema, broadcast industry.
 | 
						|
@item SEQ @tab    @tab X
 | 
						|
@tab Tiertex .seq files used in the DOS CDROM version of the game Flashback.
 | 
						|
@item DXA @tab    @tab X
 | 
						|
@tab This format is used in non-Windows version of Feeble Files game and
 | 
						|
different game cutscenes repacked for use with ScummVM.
 | 
						|
@item THP @tab    @tab X
 | 
						|
@tab Used on the Nintendo GameCube.
 | 
						|
@item C93 @tab    @tab X
 | 
						|
@tab Used in the game Cyberia from Interplay.
 | 
						|
@item Bethsoft VID @tab    @tab X
 | 
						|
@tab Used in some games from Bethesda Softworks.
 | 
						|
@item CRYO APC @tab    @tab X
 | 
						|
@tab Audio format used in some games by CRYO Interactive Entertainment.
 | 
						|
@end multitable
 | 
						|
 | 
						|
@code{X} means that encoding (resp. decoding) is supported.
 | 
						|
 | 
						|
@section Image Formats
 | 
						|
 | 
						|
FFmpeg can read and write images for each frame of a video sequence. The
 | 
						|
following image formats are supported:
 | 
						|
 | 
						|
@multitable @columnfractions .4 .1 .1 .4
 | 
						|
@item Supported Image Format @tab Encoding @tab Decoding @tab Comments
 | 
						|
@item PGM, PPM     @tab X @tab X
 | 
						|
@item PAM          @tab X @tab X @tab PAM is a PNM extension with alpha support.
 | 
						|
@item PGMYUV       @tab X @tab X @tab PGM with U and V components in YUV 4:2:0
 | 
						|
@item JPEG         @tab X @tab X @tab Progressive JPEG is not supported.
 | 
						|
@item .Y.U.V       @tab X @tab X @tab one raw file per component
 | 
						|
@item animated GIF @tab X @tab X @tab Only uncompressed GIFs are generated.
 | 
						|
@item PNG          @tab X @tab X @tab 2 bit and 4 bit/pixel not supported yet.
 | 
						|
@item Targa        @tab   @tab X @tab Targa (.TGA) image format.
 | 
						|
@item TIFF         @tab X @tab X @tab YUV, JPEG and some extension is not supported yet.
 | 
						|
@item SGI          @tab X @tab X @tab SGI RGB image format
 | 
						|
@item PTX          @tab   @tab X @tab V.Flash PTX format
 | 
						|
@end multitable
 | 
						|
 | 
						|
@code{X} means that encoding (resp. decoding) is supported.
 | 
						|
 | 
						|
@section Video Codecs
 | 
						|
 | 
						|
@multitable @columnfractions .4 .1 .1 .4
 | 
						|
@item Supported Codec @tab Encoding @tab Decoding @tab Comments
 | 
						|
@item MPEG-1 video           @tab  X  @tab  X
 | 
						|
@item MPEG-2 video           @tab  X  @tab  X
 | 
						|
@item MPEG-4                 @tab  X  @tab  X
 | 
						|
@item MSMPEG4 V1             @tab  X  @tab  X
 | 
						|
@item MSMPEG4 V2             @tab  X  @tab  X
 | 
						|
@item MSMPEG4 V3             @tab  X  @tab  X
 | 
						|
@item WMV7                   @tab  X  @tab  X
 | 
						|
@item WMV8                   @tab  X  @tab  X @tab not completely working
 | 
						|
@item WMV9                   @tab     @tab  X @tab not completely working
 | 
						|
@item VC1                    @tab     @tab  X
 | 
						|
@item H.261                  @tab  X  @tab  X
 | 
						|
@item H.263(+)               @tab  X  @tab  X @tab also known as RealVideo 1.0
 | 
						|
@item H.264                  @tab     @tab  X
 | 
						|
@item RealVideo 1.0          @tab  X  @tab  X
 | 
						|
@item RealVideo 2.0          @tab  X  @tab  X
 | 
						|
@item MJPEG                  @tab  X  @tab  X
 | 
						|
@item lossless MJPEG         @tab  X  @tab  X
 | 
						|
@item JPEG-LS                @tab  X  @tab  X @tab fourcc: MJLS, lossless and near-lossless is supported
 | 
						|
@item Apple MJPEG-B          @tab     @tab  X
 | 
						|
@item Sunplus MJPEG          @tab     @tab  X @tab fourcc: SP5X
 | 
						|
@item DV                     @tab  X  @tab  X
 | 
						|
@item HuffYUV                @tab  X  @tab  X
 | 
						|
@item FFmpeg Video 1         @tab  X  @tab  X @tab experimental lossless codec (fourcc: FFV1)
 | 
						|
@item FFmpeg Snow            @tab  X  @tab  X @tab experimental wavelet codec (fourcc: SNOW)
 | 
						|
@item Asus v1                @tab  X  @tab  X @tab fourcc: ASV1
 | 
						|
@item Asus v2                @tab  X  @tab  X @tab fourcc: ASV2
 | 
						|
@item Creative YUV           @tab     @tab  X @tab fourcc: CYUV
 | 
						|
@item Sorenson Video 1       @tab  X  @tab  X @tab fourcc: SVQ1
 | 
						|
@item Sorenson Video 3       @tab     @tab  X @tab fourcc: SVQ3
 | 
						|
@item On2 VP3                @tab     @tab  X @tab still experimental
 | 
						|
@item On2 VP5                @tab     @tab  X @tab fourcc: VP50
 | 
						|
@item On2 VP6                @tab     @tab  X @tab fourcc: VP60,VP61,VP62
 | 
						|
@item Theora                 @tab  X  @tab  X @tab still experimental
 | 
						|
@item Intel Indeo 3          @tab     @tab  X
 | 
						|
@item FLV                    @tab  X  @tab  X @tab Sorenson H.263 used in Flash
 | 
						|
@item Flash Screen Video     @tab  X  @tab  X @tab fourcc: FSV1
 | 
						|
@item ATI VCR1               @tab     @tab  X @tab fourcc: VCR1
 | 
						|
@item ATI VCR2               @tab     @tab  X @tab fourcc: VCR2
 | 
						|
@item Cirrus Logic AccuPak   @tab     @tab  X @tab fourcc: CLJR
 | 
						|
@item 4X Video               @tab     @tab  X @tab Used in certain computer games.
 | 
						|
@item Sony Playstation MDEC  @tab     @tab  X
 | 
						|
@item Id RoQ                 @tab     @tab  X @tab Used in Quake III, Jedi Knight 2, other computer games.
 | 
						|
@item Xan/WC3                @tab     @tab  X @tab Used in Wing Commander III .MVE files.
 | 
						|
@item Interplay Video        @tab     @tab  X @tab Used in Interplay .MVE files.
 | 
						|
@item Apple Animation        @tab     @tab  X @tab fourcc: 'rle '
 | 
						|
@item Apple Graphics         @tab     @tab  X @tab fourcc: 'smc '
 | 
						|
@item Apple Video            @tab     @tab  X @tab fourcc: rpza
 | 
						|
@item Apple QuickDraw        @tab     @tab  X @tab fourcc: qdrw
 | 
						|
@item Cinepak                @tab     @tab  X
 | 
						|
@item Microsoft RLE          @tab     @tab  X
 | 
						|
@item Microsoft Video-1      @tab     @tab  X
 | 
						|
@item Westwood VQA           @tab     @tab  X
 | 
						|
@item Id Cinematic Video     @tab     @tab  X @tab Used in Quake II.
 | 
						|
@item Planar RGB             @tab     @tab  X @tab fourcc: 8BPS
 | 
						|
@item FLIC video             @tab     @tab  X
 | 
						|
@item Duck TrueMotion v1     @tab     @tab  X @tab fourcc: DUCK
 | 
						|
@item Duck TrueMotion v2     @tab     @tab  X @tab fourcc: TM20
 | 
						|
@item VMD Video              @tab     @tab  X @tab Used in Sierra VMD files.
 | 
						|
@item MSZH                   @tab     @tab  X @tab Part of LCL
 | 
						|
@item ZLIB                   @tab  X  @tab  X @tab Part of LCL, encoder experimental
 | 
						|
@item TechSmith Camtasia     @tab     @tab  X @tab fourcc: TSCC
 | 
						|
@item IBM Ultimotion         @tab     @tab  X @tab fourcc: ULTI
 | 
						|
@item Miro VideoXL           @tab     @tab  X @tab fourcc: VIXL
 | 
						|
@item QPEG                   @tab     @tab  X @tab fourccs: QPEG, Q1.0, Q1.1
 | 
						|
@item LOCO                   @tab     @tab  X @tab
 | 
						|
@item Winnov WNV1            @tab     @tab  X @tab
 | 
						|
@item Autodesk Animator Studio Codec  @tab     @tab  X @tab fourcc: AASC
 | 
						|
@item Fraps FPS1             @tab     @tab  X @tab
 | 
						|
@item CamStudio              @tab     @tab  X @tab fourcc: CSCD
 | 
						|
@item American Laser Games Video  @tab    @tab X @tab Used in games like Mad Dog McCree
 | 
						|
@item ZMBV                   @tab   X @tab  X @tab Encoder works only on PAL8
 | 
						|
@item AVS Video              @tab     @tab  X @tab Video encoding used by the Creature Shock game.
 | 
						|
@item Smacker Video          @tab     @tab  X @tab Video encoding used in Smacker.
 | 
						|
@item RTjpeg                 @tab     @tab  X @tab Video encoding used in NuppelVideo files.
 | 
						|
@item KMVC                   @tab     @tab  X @tab Codec used in Worms games.
 | 
						|
@item VMware Video           @tab     @tab  X @tab Codec used in videos captured by VMware.
 | 
						|
@item Cin Video              @tab     @tab  X @tab Codec used in Delphine Software games.
 | 
						|
@item Tiertex Seq Video      @tab     @tab  X @tab Codec used in DOS CDROM FlashBack game.
 | 
						|
@item DXA Video              @tab     @tab  X @tab Codec originally used in Feeble Files game.
 | 
						|
@item AVID DNxHD             @tab     @tab  X @tab aka SMPTE VC3
 | 
						|
@item C93 Video              @tab     @tab  X @tab Codec used in Cyberia game.
 | 
						|
@item THP                    @tab     @tab  X @tab Used on the Nintendo GameCube.
 | 
						|
@item Bethsoft VID           @tab     @tab  X @tab Used in some games from Bethesda Softworks.
 | 
						|
@item Renderware TXD         @tab     @tab  X @tab Texture dictionaries used by the Renderware Engine.
 | 
						|
@end multitable
 | 
						|
 | 
						|
@code{X} means that encoding (resp. decoding) is supported.
 | 
						|
 | 
						|
@section Audio Codecs
 | 
						|
 | 
						|
@multitable @columnfractions .4 .1 .1 .1 .7
 | 
						|
@item Supported Codec @tab Encoding @tab Decoding @tab Comments
 | 
						|
@item MPEG audio layer 2     @tab  IX  @tab  IX
 | 
						|
@item MPEG audio layer 1/3   @tab IX   @tab  IX
 | 
						|
@tab MP3 encoding is supported through the external library LAME.
 | 
						|
@item AC3                    @tab  IX  @tab  IX
 | 
						|
@tab liba52 is used internally for decoding.
 | 
						|
@item Vorbis                 @tab  X   @tab  X
 | 
						|
@item WMA V1/V2              @tab X    @tab X
 | 
						|
@item AAC                    @tab X    @tab X
 | 
						|
@tab Supported through the external library libfaac/libfaad.
 | 
						|
@item Microsoft ADPCM        @tab X    @tab X
 | 
						|
@item MS IMA ADPCM           @tab X    @tab X
 | 
						|
@item QT IMA ADPCM           @tab      @tab X
 | 
						|
@item 4X IMA ADPCM           @tab      @tab X
 | 
						|
@item G.726  ADPCM           @tab X    @tab X
 | 
						|
@item Duck DK3 IMA ADPCM     @tab      @tab X
 | 
						|
@tab Used in some Sega Saturn console games.
 | 
						|
@item Duck DK4 IMA ADPCM     @tab      @tab X
 | 
						|
@tab Used in some Sega Saturn console games.
 | 
						|
@item Westwood Studios IMA ADPCM @tab      @tab X
 | 
						|
@tab Used in Westwood Studios games like Command and Conquer.
 | 
						|
@item SMJPEG IMA ADPCM       @tab      @tab X
 | 
						|
@tab Used in certain Loki game ports.
 | 
						|
@item CD-ROM XA ADPCM        @tab      @tab X
 | 
						|
@item CRI ADX ADPCM          @tab X    @tab X
 | 
						|
@tab Used in Sega Dreamcast games.
 | 
						|
@item Electronic Arts ADPCM  @tab      @tab X
 | 
						|
@tab Used in various EA titles.
 | 
						|
@item Creative ADPCM         @tab      @tab X
 | 
						|
@tab 16 -> 4, 8 -> 4, 8 -> 3, 8 -> 2
 | 
						|
@item THP ADPCM              @tab      @tab X
 | 
						|
@tab Used on the Nintendo GameCube.
 | 
						|
@item RA144                  @tab      @tab X
 | 
						|
@tab Real 14400 bit/s codec
 | 
						|
@item RA288                  @tab      @tab X
 | 
						|
@tab Real 28800 bit/s codec
 | 
						|
@item RADnet                 @tab X    @tab IX
 | 
						|
@tab Real low bitrate AC3 codec, liba52 is used for decoding.
 | 
						|
@item AMR-NB                 @tab X    @tab X
 | 
						|
@tab Supported through an external library.
 | 
						|
@item AMR-WB                 @tab X    @tab X
 | 
						|
@tab Supported through an external library.
 | 
						|
@item DV audio               @tab      @tab X
 | 
						|
@item Id RoQ DPCM            @tab X    @tab X
 | 
						|
@tab Used in Quake III, Jedi Knight 2, other computer games.
 | 
						|
@item Interplay MVE DPCM     @tab      @tab X
 | 
						|
@tab Used in various Interplay computer games.
 | 
						|
@item Xan DPCM               @tab      @tab X
 | 
						|
@tab Used in Origin's Wing Commander IV AVI files.
 | 
						|
@item Sierra Online DPCM     @tab      @tab X
 | 
						|
@tab Used in Sierra Online game audio files.
 | 
						|
@item Apple MACE 3           @tab      @tab X
 | 
						|
@item Apple MACE 6           @tab      @tab X
 | 
						|
@item FLAC lossless audio    @tab X    @tab X
 | 
						|
@item Shorten lossless audio @tab      @tab X
 | 
						|
@item Apple lossless audio   @tab      @tab X
 | 
						|
@tab QuickTime fourcc 'alac'
 | 
						|
@item FFmpeg Sonic           @tab X    @tab X
 | 
						|
@tab experimental lossy/lossless codec
 | 
						|
@item Qdesign QDM2           @tab      @tab X
 | 
						|
@tab there are still some distortions
 | 
						|
@item Real COOK              @tab      @tab X
 | 
						|
@tab All versions except 5.1 are supported
 | 
						|
@item DSP Group TrueSpeech   @tab      @tab X
 | 
						|
@item True Audio (TTA)       @tab      @tab X
 | 
						|
@item Smacker Audio          @tab      @tab X
 | 
						|
@item WavPack Audio          @tab      @tab X
 | 
						|
@item Cin Audio              @tab      @tab X
 | 
						|
@tab Codec used in Delphine Software games.
 | 
						|
@item Intel Music Coder      @tab      @tab X
 | 
						|
@item Musepack               @tab      @tab X
 | 
						|
@tab Only SV7 is supported
 | 
						|
@item DT$ Coherent Audio     @tab      @tab X
 | 
						|
@item ATRAC 3                @tab      @tab X
 | 
						|
@end multitable
 | 
						|
 | 
						|
@code{X} means that encoding (resp. decoding) is supported.
 | 
						|
 | 
						|
@code{I} means that an integer-only version is available, too (ensures high
 | 
						|
performance on systems without hardware floating point support).
 | 
						|
 | 
						|
@chapter Platform Specific information
 | 
						|
 | 
						|
@section BSD
 | 
						|
 | 
						|
BSD make will not build FFmpeg, you need to install and use GNU Make
 | 
						|
(@file{gmake}).
 | 
						|
 | 
						|
@section Windows
 | 
						|
 | 
						|
To get help and instructions for using FFmpeg under Windows, check out
 | 
						|
the FFmpeg Windows Help Forum at
 | 
						|
@url{http://arrozcru.no-ip.org/ffmpeg/}.
 | 
						|
 | 
						|
@subsection Native Windows compilation
 | 
						|
 | 
						|
@itemize
 | 
						|
@item Install the current versions of MSYS and MinGW from
 | 
						|
@url{http://www.mingw.org/}. You can find detailed installation
 | 
						|
instructions in the download section and the FAQ.
 | 
						|
 | 
						|
NOTE: Use at least bash 3.1. Older versions are known to be failing on the
 | 
						|
configure script.
 | 
						|
 | 
						|
@item If you want to test the FFplay, also download
 | 
						|
the MinGW development library of SDL 1.2.x
 | 
						|
(@file{SDL-devel-1.2.x-mingw32.tar.gz}) from
 | 
						|
@url{http://www.libsdl.org}. Unpack it in a temporary directory, and
 | 
						|
unpack the archive @file{i386-mingw32msvc.tar.gz} in the MinGW tool
 | 
						|
directory. Edit the @file{sdl-config} script so that it gives the
 | 
						|
correct SDL directory when invoked.
 | 
						|
 | 
						|
@item Extract the current version of FFmpeg.
 | 
						|
 | 
						|
@item Start the MSYS shell (file @file{msys.bat}).
 | 
						|
 | 
						|
@item Change to the FFmpeg directory and follow
 | 
						|
 the instructions of how to compile FFmpeg (file
 | 
						|
@file{INSTALL}). Usually, launching @file{./configure} and @file{make}
 | 
						|
suffices. If you have problems using SDL, verify that
 | 
						|
@file{sdl-config} can be launched from the MSYS command line.
 | 
						|
 | 
						|
@item You can install FFmpeg in @file{Program Files/FFmpeg} by typing
 | 
						|
@file{make install}. Do not forget to copy @file{SDL.dll} to the place
 | 
						|
you launch @file{ffplay} from.
 | 
						|
 | 
						|
@end itemize
 | 
						|
 | 
						|
Notes:
 | 
						|
@itemize
 | 
						|
 | 
						|
@item The target @file{make wininstaller} can be used to create a
 | 
						|
Nullsoft based Windows installer for FFmpeg and FFplay. @file{SDL.dll}
 | 
						|
must be copied to the FFmpeg directory in order to build the
 | 
						|
installer.
 | 
						|
 | 
						|
@item By using @code{./configure --enable-shared} when configuring FFmpeg,
 | 
						|
you can build @file{avcodec.dll} and @file{avformat.dll}. With
 | 
						|
@code{make install} you install the FFmpeg DLLs and the associated
 | 
						|
headers in @file{Program Files/FFmpeg}.
 | 
						|
 | 
						|
@item Visual C++ compatibility: If you used @code{./configure --enable-shared}
 | 
						|
when configuring FFmpeg, FFmpeg tries to use the Microsoft Visual
 | 
						|
C++ @code{lib} tool to build @code{avcodec.lib} and
 | 
						|
@code{avformat.lib}. With these libraries you can link your Visual C++
 | 
						|
code directly with the FFmpeg DLLs (see below).
 | 
						|
 | 
						|
@end itemize
 | 
						|
 | 
						|
@subsection Visual C++ compatibility
 | 
						|
 | 
						|
FFmpeg will not compile under Visual C++ -- and it has too many
 | 
						|
dependencies on the GCC compiler to make a port viable. However,
 | 
						|
if you want to use the FFmpeg libraries in your own applications,
 | 
						|
you can still compile those applications using Visual C++. An
 | 
						|
important restriction to this is that you have to use the
 | 
						|
dynamically linked versions of the FFmpeg libraries (i.e. the
 | 
						|
DLLs), and you have to make sure that Visual-C++-compatible
 | 
						|
import libraries are created during the FFmpeg build process.
 | 
						|
 | 
						|
This description of how to use the FFmpeg libraries with Visual C++ is
 | 
						|
based on Visual C++ 2005 Express Edition Beta 2. If you have a different
 | 
						|
version, you might have to modify the procedures slightly.
 | 
						|
 | 
						|
Here are the step-by-step instructions for building the FFmpeg libraries
 | 
						|
so they can be used with Visual C++:
 | 
						|
 | 
						|
@enumerate
 | 
						|
 | 
						|
@item Install Visual C++ (if you have not done so already).
 | 
						|
 | 
						|
@item Install MinGW and MSYS as described above.
 | 
						|
 | 
						|
@item Add a call to @file{vcvars32.bat} (which sets up the environment
 | 
						|
variables for the Visual C++ tools) as the first line of
 | 
						|
@file{msys.bat}. The standard location for @file{vcvars32.bat} is
 | 
						|
@file{C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat},
 | 
						|
and the standard location for @file{msys.bat} is
 | 
						|
@file{C:\msys\1.0\msys.bat}. If this corresponds to your setup, add the
 | 
						|
following line as the first line of @file{msys.bat}:
 | 
						|
 | 
						|
@code{call "C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat"}
 | 
						|
 | 
						|
@item Start the MSYS shell (file @file{msys.bat}) and type @code{link.exe}.
 | 
						|
If you get a help message with the command line options of @code{link.exe},
 | 
						|
this means your environment variables are set up correctly, the
 | 
						|
Microsoft linker is on the path and will be used by FFmpeg to
 | 
						|
create Visual-C++-compatible import libraries.
 | 
						|
 | 
						|
@item Extract the current version of FFmpeg and change to the FFmpeg directory.
 | 
						|
 | 
						|
@item Type the command
 | 
						|
@code{./configure --enable-shared --disable-static --enable-memalign-hack}
 | 
						|
to configure and, if that did not produce any errors,
 | 
						|
type @code{make} to build FFmpeg.
 | 
						|
 | 
						|
@item The subdirectories @file{libavformat}, @file{libavcodec}, and
 | 
						|
@file{libavutil} should now contain the files @file{avformat.dll},
 | 
						|
@file{avformat.lib}, @file{avcodec.dll}, @file{avcodec.lib},
 | 
						|
@file{avutil.dll}, and @file{avutil.lib}, respectively. Copy the three
 | 
						|
DLLs to your System32 directory (typically @file{C:\Windows\System32}).
 | 
						|
 | 
						|
@end enumerate
 | 
						|
 | 
						|
And here is how to use these libraries with Visual C++:
 | 
						|
 | 
						|
@enumerate
 | 
						|
 | 
						|
@item Create a new console application ("File / New / Project") and then
 | 
						|
select "Win32 Console Application". On the appropriate page of the
 | 
						|
Application Wizard, uncheck the "Precompiled headers" option.
 | 
						|
 | 
						|
@item Write the source code for your application, or, for testing, just
 | 
						|
copy the code from an existing sample application into the source file
 | 
						|
that Visual C++ has already created for you. (Note that your source
 | 
						|
filehas to have a @code{.cpp} extension; otherwise, Visual C++ will not
 | 
						|
compile the FFmpeg headers correctly because in C mode, it does not
 | 
						|
recognize the @code{inline} keyword.)  For example, you can copy
 | 
						|
@file{output_example.c} from the FFmpeg distribution (but you will
 | 
						|
have to make minor modifications so the code will compile under
 | 
						|
C++, see below).
 | 
						|
 | 
						|
@item Open the "Project / Properties" dialog box. In the "Configuration"
 | 
						|
combo box, select "All Configurations" so that the changes you make will
 | 
						|
affect both debug and release builds. In the tree view on the left hand
 | 
						|
side, select "C/C++ / General", then edit the "Additional Include
 | 
						|
Directories" setting to contain the complete paths to the
 | 
						|
@file{libavformat}, @file{libavcodec}, and @file{libavutil}
 | 
						|
subdirectories of your FFmpeg directory. Note that the directories have
 | 
						|
to be separated using semicolons. Now select "Linker / General" from the
 | 
						|
tree view and edit the "Additional Library Directories" setting to
 | 
						|
contain the same three directories.
 | 
						|
 | 
						|
@item Still in the "Project / Properties" dialog box, select "Linker / Input"
 | 
						|
from the tree view, then add the files @file{avformat.lib},
 | 
						|
@file{avcodec.lib}, and @file{avutil.lib} to the end of the "Additional
 | 
						|
Dependencies". Note that the names of the libraries have to be separated
 | 
						|
using spaces.
 | 
						|
 | 
						|
@item Now, select "C/C++ / Code Generation" from the tree view. Select
 | 
						|
"Debug" in the "Configuration" combo box. Make sure that "Runtime
 | 
						|
Library" is set to "Multi-threaded Debug DLL". Then, select "Release" in
 | 
						|
the "Configuration" combo box and make sure that "Runtime Library" is
 | 
						|
set to "Multi-threaded DLL".
 | 
						|
 | 
						|
@item Click "OK" to close the "Project / Properties" dialog box and build
 | 
						|
the application. Hopefully, it should compile and run cleanly. If you
 | 
						|
used @file{output_example.c} as your sample application, you will get a
 | 
						|
few compiler errors, but they are easy to fix. The first type of error
 | 
						|
occurs because Visual C++ does not allow an @code{int} to be converted to
 | 
						|
an @code{enum} without a cast. To solve the problem, insert the required
 | 
						|
casts (this error occurs once for a @code{CodecID} and once for a
 | 
						|
@code{CodecType}).  The second type of error occurs because C++ requires
 | 
						|
the return value of @code{malloc} to be cast to the exact type of the
 | 
						|
pointer it is being assigned to. Visual C++ will complain that, for
 | 
						|
example, @code{(void *)} is being assigned to @code{(uint8_t *)} without
 | 
						|
an explicit cast. So insert an explicit cast in these places to silence
 | 
						|
the compiler. The third type of error occurs because the @code{snprintf}
 | 
						|
library function is called @code{_snprintf} under Visual C++.  So just
 | 
						|
add an underscore to fix the problem. With these changes,
 | 
						|
@file{output_example.c} should compile under Visual C++, and the
 | 
						|
resulting executable should produce valid video files.
 | 
						|
 | 
						|
@end enumerate
 | 
						|
 | 
						|
@subsection Cross compilation for Windows with Linux
 | 
						|
 | 
						|
You must use the MinGW cross compilation tools available at
 | 
						|
@url{http://www.mingw.org/}.
 | 
						|
 | 
						|
Then configure FFmpeg with the following options:
 | 
						|
@example
 | 
						|
./configure --target-os=mingw32 --cross-prefix=i386-mingw32msvc-
 | 
						|
@end example
 | 
						|
(you can change the cross-prefix according to the prefix chosen for the
 | 
						|
MinGW tools).
 | 
						|
 | 
						|
Then you can easily test FFmpeg with Wine
 | 
						|
(@url{http://www.winehq.com/}).
 | 
						|
 | 
						|
@subsection Compilation under Cygwin
 | 
						|
 | 
						|
Cygwin works very much like Unix.
 | 
						|
 | 
						|
Just install your Cygwin with all the "Base" packages, plus the
 | 
						|
following "Devel" ones:
 | 
						|
@example
 | 
						|
binutils, gcc-core, make, subversion
 | 
						|
@end example
 | 
						|
 | 
						|
Do not install binutils-20060709-1 (they are buggy on shared builds);
 | 
						|
use binutils-20050610-1 instead.
 | 
						|
 | 
						|
Then run
 | 
						|
 | 
						|
@example
 | 
						|
./configure --enable-static --disable-shared
 | 
						|
@end example
 | 
						|
 | 
						|
to make a static build or
 | 
						|
 | 
						|
@example
 | 
						|
./configure --enable-shared --disable-static
 | 
						|
@end example
 | 
						|
 | 
						|
to build shared libraries.
 | 
						|
 | 
						|
If you want to build FFmpeg with additional libraries, download Cygwin
 | 
						|
"Devel" packages for Ogg and Vorbis from any Cygwin packages repository
 | 
						|
and/or SDL, xvid, faac, faad2 packages from Cygwin Ports,
 | 
						|
(@url{http://cygwinports.dotsrc.org/}).
 | 
						|
 | 
						|
@subsection Crosscompilation for Windows under Cygwin
 | 
						|
 | 
						|
With Cygwin you can create Windows binaries that do not need the cygwin1.dll.
 | 
						|
 | 
						|
Just install your Cygwin as explained before, plus these additional
 | 
						|
"Devel" packages:
 | 
						|
@example
 | 
						|
gcc-mingw-core, mingw-runtime, mingw-zlib
 | 
						|
@end example
 | 
						|
 | 
						|
and add some special flags to your configure invocation.
 | 
						|
 | 
						|
For a static build run
 | 
						|
@example
 | 
						|
./configure --target-os=mingw32 --enable-memalign-hack --enable-static --disable-shared --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
 | 
						|
@end example
 | 
						|
 | 
						|
and for a build with shared libraries
 | 
						|
@example
 | 
						|
./configure --target-os=mingw32 --enable-memalign-hack --enable-shared --disable-static --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
 | 
						|
@end example
 | 
						|
 | 
						|
@section BeOS
 | 
						|
 | 
						|
The configure script should guess the configuration itself.
 | 
						|
Networking support is currently not finished.
 | 
						|
errno issues fixed by Andrew Bachmann.
 | 
						|
 | 
						|
Old stuff:
 | 
						|
 | 
						|
François Revol - revol at free dot fr - April 2002
 | 
						|
 | 
						|
The configure script should guess the configuration itself,
 | 
						|
however I still did not test building on the net_server version of BeOS.
 | 
						|
 | 
						|
FFserver is broken (needs poll() implementation).
 | 
						|
 | 
						|
There are still issues with errno codes, which are negative in BeOS, and
 | 
						|
that FFmpeg negates when returning. This ends up turning errors into
 | 
						|
valid results, then crashes.
 | 
						|
(To be fixed)
 | 
						|
 | 
						|
@chapter Developers Guide
 | 
						|
 | 
						|
@section API
 | 
						|
@itemize @bullet
 | 
						|
@item libavcodec is the library containing the codecs (both encoding and
 | 
						|
decoding). Look at @file{libavcodec/apiexample.c} to see how to use it.
 | 
						|
 | 
						|
@item libavformat is the library containing the file format handling (mux and
 | 
						|
demux code for several formats). Look at @file{ffplay.c} to use it in a
 | 
						|
player. See @file{output_example.c} to use it to generate audio or video
 | 
						|
streams.
 | 
						|
 | 
						|
@end itemize
 | 
						|
 | 
						|
@section Integrating libavcodec or libavformat in your program
 | 
						|
 | 
						|
You can integrate all the source code of the libraries to link them
 | 
						|
statically to avoid any version problem. All you need is to provide a
 | 
						|
'config.mak' and a 'config.h' in the parent directory. See the defines
 | 
						|
generated by ./configure to understand what is needed.
 | 
						|
 | 
						|
You can use libavcodec or libavformat in your commercial program, but
 | 
						|
@emph{any patch you make must be published}. The best way to proceed is
 | 
						|
to send your patches to the FFmpeg mailing list.
 | 
						|
 | 
						|
@node Coding Rules
 | 
						|
@section Coding Rules
 | 
						|
 | 
						|
FFmpeg is programmed in the ISO C90 language with a few additional
 | 
						|
features from ISO C99, namely:
 | 
						|
@itemize @bullet
 | 
						|
@item
 | 
						|
the @samp{inline} keyword;
 | 
						|
@item
 | 
						|
@samp{//} comments;
 | 
						|
@item
 | 
						|
designated struct initializers (@samp{struct s x = @{ .i = 17 @};})
 | 
						|
@item
 | 
						|
compound literals (@samp{x = (struct s) @{ 17, 23 @};})
 | 
						|
@end itemize
 | 
						|
 | 
						|
These features are supported by all compilers we care about, so we will not
 | 
						|
accept patches to remove their use unless they absolutely do not impair
 | 
						|
clarity and performance.
 | 
						|
 | 
						|
All code must compile with GCC 2.95 and GCC 3.3. Currently, FFmpeg also
 | 
						|
compiles with several other compilers, such as the Compaq ccc compiler
 | 
						|
or Sun Studio 9, and we would like to keep it that way unless it would
 | 
						|
be exceedingly involved. To ensure compatibility, please do not use any
 | 
						|
additional C99 features or GCC extensions. Especially watch out for:
 | 
						|
@itemize @bullet
 | 
						|
@item
 | 
						|
mixing statements and declarations;
 | 
						|
@item
 | 
						|
@samp{long long} (use @samp{int64_t} instead);
 | 
						|
@item
 | 
						|
@samp{__attribute__} not protected by @samp{#ifdef __GNUC__} or similar;
 | 
						|
@item
 | 
						|
GCC statement expressions (@samp{(x = (@{ int y = 4; y; @})}).
 | 
						|
@end itemize
 | 
						|
 | 
						|
Indent size is 4.
 | 
						|
The presentation is the one specified by 'indent -i4 -kr -nut'.
 | 
						|
The TAB character is forbidden outside of Makefiles as is any
 | 
						|
form of trailing whitespace. Commits containing either will be
 | 
						|
rejected by the Subversion repository.
 | 
						|
 | 
						|
Main priority in FFmpeg is simplicity and small code size (=less
 | 
						|
bugs).
 | 
						|
 | 
						|
Comments: Use the JavaDoc/Doxygen
 | 
						|
format (see examples below) so that code documentation
 | 
						|
can be generated automatically. All nontrivial functions should have a comment
 | 
						|
above them explaining what the function does, even if it is just one sentence.
 | 
						|
All structures and their member variables should be documented, too.
 | 
						|
@example
 | 
						|
/**
 | 
						|
 * @@file mpeg.c
 | 
						|
 * MPEG codec.
 | 
						|
 * @@author ...
 | 
						|
 */
 | 
						|
 | 
						|
/**
 | 
						|
 * Summary sentence.
 | 
						|
 * more text ...
 | 
						|
 * ...
 | 
						|
 */
 | 
						|
typedef struct Foobar@{
 | 
						|
    int var1; /**< var1 description */
 | 
						|
    int var2; ///< var2 description
 | 
						|
    /** var3 description */
 | 
						|
    int var3;
 | 
						|
@} Foobar;
 | 
						|
 | 
						|
/**
 | 
						|
 * Summary sentence.
 | 
						|
 * more text ...
 | 
						|
 * ...
 | 
						|
 * @@param my_parameter description of my_parameter
 | 
						|
 * @@return return value description
 | 
						|
 */
 | 
						|
int myfunc(int my_parameter)
 | 
						|
...
 | 
						|
@end example
 | 
						|
 | 
						|
fprintf and printf are forbidden in libavformat and libavcodec,
 | 
						|
please use av_log() instead.
 | 
						|
 | 
						|
@section Development Policy
 | 
						|
 | 
						|
@enumerate
 | 
						|
@item
 | 
						|
   You must not commit code which breaks FFmpeg! (Meaning unfinished but
 | 
						|
   enabled code which breaks compilation or compiles but does not work or
 | 
						|
   breaks the regression tests)
 | 
						|
   You can commit unfinished stuff (for testing etc), but it must be disabled
 | 
						|
   (#ifdef etc) by default so it does not interfere with other developers'
 | 
						|
   work.
 | 
						|
@item
 | 
						|
   You do not have to over-test things. If it works for you, and you think it
 | 
						|
   should work for others, then commit. If your code has problems
 | 
						|
   (portability, triggers compiler bugs, unusual environment etc) they will be
 | 
						|
   reported and eventually fixed.
 | 
						|
@item
 | 
						|
   Do not commit unrelated changes together, split them into self-contained
 | 
						|
   pieces. Also do not forget that if part B depends on part A, but A does not
 | 
						|
   depend on B, then A can and should be committed first and separate from B.
 | 
						|
   Keeping changes well split into self-contained parts makes reviewing and
 | 
						|
   understanding them on the commit log mailing list easier. This also helps
 | 
						|
   in case of debugging later on.
 | 
						|
   Also if you have doubts about splitting or not splitting, do not hesitate to
 | 
						|
   ask/discuss it on the developer mailing list.
 | 
						|
@item
 | 
						|
   Do not change behavior of the program (renaming options etc) without
 | 
						|
   first discussing it on the ffmpeg-devel mailing list. Do not remove
 | 
						|
   functionality from the code. Just improve!
 | 
						|
 | 
						|
   Note: Redundant code can be removed.
 | 
						|
@item
 | 
						|
   Do not commit changes to the build system (Makefiles, configure script)
 | 
						|
   which change behavior, defaults etc, without asking first. The same
 | 
						|
   applies to compiler warning fixes, trivial looking fixes and to code
 | 
						|
   maintained by other developers. We usually have a reason for doing things
 | 
						|
   the way we do. Send your changes as patches to the ffmpeg-devel mailing
 | 
						|
   list, and if the code maintainers say OK, you may commit. This does not
 | 
						|
   apply to files you wrote and/or maintain.
 | 
						|
@item
 | 
						|
   We refuse source indentation and other cosmetic changes if they are mixed
 | 
						|
   with functional changes, such commits will be rejected and removed. Every
 | 
						|
   developer has his own indentation style, you should not change it. Of course
 | 
						|
   if you (re)write something, you can use your own style, even though we would
 | 
						|
   prefer if the indentation throughout FFmpeg was consistent (Many projects
 | 
						|
   force a given indentation style - we do not.). If you really need to make
 | 
						|
   indentation changes (try to avoid this), separate them strictly from real
 | 
						|
   changes.
 | 
						|
 | 
						|
   NOTE: If you had to put if()@{ .. @} over a large (> 5 lines) chunk of code,
 | 
						|
   then either do NOT change the indentation of the inner part within (do not
 | 
						|
   move it to the right)! or do so in a separate commit
 | 
						|
@item
 | 
						|
   Always fill out the commit log message. Describe in a few lines what you
 | 
						|
   changed and why. You can refer to mailing list postings if you fix a
 | 
						|
   particular bug. Comments such as "fixed!" or "Changed it." are unacceptable.
 | 
						|
@item
 | 
						|
   If you apply a patch by someone else, include the name and email address in
 | 
						|
   the log message. Since the ffmpeg-cvslog mailing list is publicly
 | 
						|
   archived you should add some SPAM protection to the email address. Send an
 | 
						|
   answer to ffmpeg-devel (or wherever you got the patch from) saying that
 | 
						|
   you applied the patch.
 | 
						|
@item
 | 
						|
   When applying patches that have been discussed (at length) on the mailing
 | 
						|
   list, reference the thread in the log message.
 | 
						|
@item
 | 
						|
    Do NOT commit to code actively maintained by others without permission.
 | 
						|
    Send a patch to ffmpeg-devel instead. If noone answers within a reasonable
 | 
						|
    timeframe (12h for build failures and security fixes, 3 days small changes,
 | 
						|
    1 week for big patches) then commit your patch if you think it is OK.
 | 
						|
    Also note, the maintainer can simply ask for more time to review!
 | 
						|
@item
 | 
						|
    Subscribe to the ffmpeg-cvslog mailing list. The diffs of all commits
 | 
						|
    are sent there and reviewed by all the other developers. Bugs and possible
 | 
						|
    improvements or general questions regarding commits are discussed there. We
 | 
						|
    expect you to react if problems with your code are uncovered.
 | 
						|
@item
 | 
						|
    Update the documentation if you change behavior or add features. If you are
 | 
						|
    unsure how best to do this, send a patch to ffmpeg-devel, the documentation
 | 
						|
    maintainer(s) will review and commit your stuff.
 | 
						|
@item
 | 
						|
    Try to keep important discussions and requests (also) on the public
 | 
						|
    developer mailing list, so that all developers can benefit from them.
 | 
						|
@item
 | 
						|
    Never write to unallocated memory, never write over the end of arrays,
 | 
						|
    always check values read from some untrusted source before using them
 | 
						|
    as array index or other risky things.
 | 
						|
@item
 | 
						|
    Remember to check if you need to bump versions for the specific libav
 | 
						|
    parts (libavutil, libavcodec, libavformat) you are changing. You need
 | 
						|
    to change the version integer and the version string.
 | 
						|
    Incrementing the first component means no backward compatibility to
 | 
						|
    previous versions (e.g. removal of a function from the public API).
 | 
						|
    Incrementing the second component means backward compatible change
 | 
						|
    (e.g. addition of a function to the public API).
 | 
						|
    Incrementing the third component means a noteworthy binary compatible
 | 
						|
    change (e.g. encoder bug fix that matters for the decoder).
 | 
						|
@item
 | 
						|
    If you add a new codec, remember to update the changelog, add it to
 | 
						|
    the supported codecs table in the documentation and bump the second
 | 
						|
    component of the @file{libavcodec} version number appropriately. If
 | 
						|
    it has a fourcc, add it to @file{libavformat/avienc.c}, even if it
 | 
						|
    is only a decoder.
 | 
						|
@item
 | 
						|
    Do not change code to hide warnings without ensuring that the underlying
 | 
						|
    logic is correct and thus the warning was inappropriate.
 | 
						|
@item
 | 
						|
    If you add a new file, give it a proper license header. Do not copy and
 | 
						|
    paste it from a random place, use an existing file as template.
 | 
						|
@end enumerate
 | 
						|
 | 
						|
We think our rules are not too hard. If you have comments, contact us.
 | 
						|
 | 
						|
Note, these rules are mostly borrowed from the MPlayer project.
 | 
						|
 | 
						|
@section Submitting patches
 | 
						|
 | 
						|
First, (@pxref{Coding Rules}) above if you did not yet.
 | 
						|
 | 
						|
When you submit your patch, try to send a unified diff (diff '-up'
 | 
						|
option). I cannot read other diffs :-)
 | 
						|
 | 
						|
Also please do not submit patches which contain several unrelated changes.
 | 
						|
Split them into individual self-contained patches; this makes reviewing
 | 
						|
them much easier.
 | 
						|
 | 
						|
Run the regression tests before submitting a patch so that you can
 | 
						|
verify that there are no big problems.
 | 
						|
 | 
						|
Patches should be posted as base64 encoded attachments (or any other
 | 
						|
encoding which ensures that the patch will not be trashed during
 | 
						|
transmission) to the ffmpeg-devel mailing list, see
 | 
						|
@url{http://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel}
 | 
						|
 | 
						|
It also helps quite a bit if you tell us what the patch does (for example
 | 
						|
'replaces lrint by lrintf'), and why (for example '*BSD isn't C99 compliant
 | 
						|
and has no lrint()')
 | 
						|
 | 
						|
Also please if you send several patches, send each patch as separate mail,
 | 
						|
do not attach several unrelated patches to the same mail.
 | 
						|
 | 
						|
@section patch submission checklist
 | 
						|
 | 
						|
@enumerate
 | 
						|
@item
 | 
						|
    Do the regression tests pass with the patch applied?
 | 
						|
@item
 | 
						|
    Is the patch a unified diff?
 | 
						|
@item
 | 
						|
    Is the patch against latest FFmpeg SVN?
 | 
						|
@item
 | 
						|
    Are you subscribed to ffmpeg-dev?
 | 
						|
    (the list is subscribers only due to spam)
 | 
						|
@item
 | 
						|
    Have you checked that the changes are minimal, so that the same cannot be
 | 
						|
    achieved with a smaller patch and/or simpler final code?
 | 
						|
@item
 | 
						|
    If the change is to speed critical code, did you benchmark it?
 | 
						|
@item
 | 
						|
    If you did any benchmarks, did you provide them in the mail?
 | 
						|
@item
 | 
						|
    Have you checked that the patch does not introduce buffer overflows or
 | 
						|
    other security issues?
 | 
						|
@item
 | 
						|
    Is the patch created from the root of the source tree, so it can be
 | 
						|
    applied with @code{patch -p0}?
 | 
						|
@item
 | 
						|
    Does the patch not mix functional and cosmetic changes?
 | 
						|
@item
 | 
						|
    Did you add tabs or trailing whitespace to the code? Both are forbidden.
 | 
						|
@item
 | 
						|
    Is the patch attached to the email you send?
 | 
						|
@item
 | 
						|
    Is the mime type of the patch correct? It should be text/x-diff or
 | 
						|
    text/x-patch or at least text/plain and not application/octet-stream.
 | 
						|
@item
 | 
						|
    If the patch fixes a bug, did you provide a verbose analysis of the bug?
 | 
						|
@item
 | 
						|
    If the patch fixes a bug, did you provide enough information, including
 | 
						|
    a sample, so the bug can be reproduced and the fix can be verified?
 | 
						|
@item
 | 
						|
    Did you provide a verbose summary about what the patch does change?
 | 
						|
@item
 | 
						|
    Did you provide a verbose explanation why it changes things like it does?
 | 
						|
@item
 | 
						|
    Did you provide a verbose summary of the user visible advantages and
 | 
						|
    disadvantages if the patch is applied?
 | 
						|
@item
 | 
						|
    Did you provide an example so we can verify the new feature added by the
 | 
						|
    patch easily?
 | 
						|
@item
 | 
						|
    If you added a new file, did you insert a license header? It should be
 | 
						|
    taken from FFmpeg, not randomly copied and pasted from somewhere else.
 | 
						|
@item
 | 
						|
    You should maintain alphabetical order in alphabetically ordered lists as
 | 
						|
    long as doing so does not break API/ABI compatibility.
 | 
						|
@item
 | 
						|
    Did you provide a suggestion for a clear commit log message?
 | 
						|
@end enumerate
 | 
						|
 | 
						|
@section Patch review process
 | 
						|
 | 
						|
All patches posted to ffmpeg-devel will be reviewed, unless they contain a
 | 
						|
clear note that the patch is not for SVN.
 | 
						|
Reviews and comments will be posted as replies to the patch on the
 | 
						|
mailing list. The patch submitter then has to take care of every comment,
 | 
						|
that can be by resubmitting a changed patch or by discussion. Resubmitted
 | 
						|
patches will themselves be reviewed like any other patch. If at some point
 | 
						|
a patch passes review with no comments then it is approved, that can for
 | 
						|
simple and small patches happen immediately while large patches will generally
 | 
						|
have to be changed and reviewed many times before they are approved.
 | 
						|
After a patch is approved it will be committed to the repository.
 | 
						|
 | 
						|
We will review all submitted patches, but sometimes we are quite busy so
 | 
						|
especially for large patches this can take several weeks.
 | 
						|
 | 
						|
When resubmitting patches, please do not make any significant changes
 | 
						|
not related to the comments received during review. Such patches will
 | 
						|
be rejected. Instead, submit  significant changes or new features as
 | 
						|
separate patches.
 | 
						|
 | 
						|
@section Regression tests
 | 
						|
 | 
						|
Before submitting a patch (or committing to the repository), you should at least
 | 
						|
test that you did not break anything.
 | 
						|
 | 
						|
The regression tests build a synthetic video stream and a synthetic
 | 
						|
audio stream. These are then encoded and decoded with all codecs or
 | 
						|
formats. The CRC (or MD5) of each generated file is recorded in a
 | 
						|
result file. A 'diff' is launched to compare the reference results and
 | 
						|
the result file.
 | 
						|
 | 
						|
The regression tests then go on to test the FFserver code with a
 | 
						|
limited set of streams. It is important that this step runs correctly
 | 
						|
as well.
 | 
						|
 | 
						|
Run 'make test' to test all the codecs and formats.
 | 
						|
 | 
						|
Run 'make fulltest' to test all the codecs, formats and FFserver.
 | 
						|
 | 
						|
[Of course, some patches may change the results of the regression tests. In
 | 
						|
this case, the reference results of the regression tests shall be modified
 | 
						|
accordingly].
 | 
						|
 | 
						|
@bye
 |