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
System audio source:
@example
-ffmpeg /tmp/out.mpg
+ffmpeg /tmp/out.mpg
@end example
Note that you must activate the right video source and channel before
* You can use YUV files as input:
@example
-ffmpeg -i /tmp/test%d.Y /tmp/out.mpg
+ffmpeg -i /tmp/test%d.Y /tmp/out.mpg
@end example
-It will use the files:
+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...
* You can transcode decrypted VOBs
@example
-ffmpeg -i snatch_1.vob -f avi -vcodec mpeg4 -b 800 -g 300 -bf 2 -acodec mp3 -ab 128 snatch.avi
+ffmpeg -i snatch_1.vob -f avi -vcodec mpeg4 -b 800k -g 300 -bf 2 -acodec mp3 -ab 128 snatch.avi
@end example
This is a typical DVD ripping example; the input is a VOB file, the
The generic syntax is:
-@example
+@example
@c man begin SYNOPSIS
ffmpeg [[infile options][@option{-i} @var{infile}]]... @{[outfile options] @var{outfile}@}...
@c man end
If no input file is given, audio/video grabbing is done.
As a general rule, options are applied to the next specified
-file. For example, if you give the @option{-b 64} option, it sets the video
+file. For example, if you give the @option{-b 64k} option, it sets the video
bitrate of the next file. The format option may be needed for raw input
files.
@item -formats
Show available formats, codecs, protocols, ...
-@item -f fmt
+@item -f fmt
Force format.
-@item -i filename
+@item -i filename
input filename
-@item -y
+@item -y
Overwrite output files.
-@item -t duration
+@item -t duration
Set the recording time in seconds.
@code{hh:mm:ss[.xxx]} syntax is also supported.
Seek to given time position in seconds.
@code{hh:mm:ss[.xxx]} syntax is also supported.
-@item -title string
+@item -title string
Set the title.
-@item -author string
+@item -author string
Set the author.
-@item -copyright string
+@item -copyright string
Set the copyright.
-@item -comment string
+@item -comment string
Set the comment.
+@item -track number
+Set the track.
+
+@item -year number
+Set the year.
+
@item -target type
Specify target file type ("vcd", "svcd", "dvd", "dv", "pal-vcd",
"ntsc-svcd", ... ). All the format options (bitrate, codecs,
ffmpeg -i myfile.avi -target vcd -bf 2 /tmp/vcd.mpg
@end example
-@item -hq
-Activate high quality settings.
-
@item -itsoffset offset
Set the input time offset in seconds.
@code{[-]hh:mm:ss[.xxx]} syntax is also supported.
@table @option
@item -b bitrate
-Set the video bitrate in kbit/s (default = 200 kb/s).
-@item -r fps
+Set the video bitrate in bit/s (default = 200 kb/s).
+@item -r fps
Set frame rate (default = 25).
-@item -s size
+@item -s size
Set frame size. The format is @samp{wxh} (default = 160x128).
The following abbreviations are recognized:
@table @samp
blue (default = 000000 (black)).
@item -vn
Disable video recording.
-@item -bt tolerance
-Set video bitrate tolerance (in kbit/s).
+@item -bt tolerance
+Set video bitrate tolerance (in bit/s).
@item -maxrate bitrate
-Set max video bitrate tolerance (in kbit/s).
+Set max video bitrate tolerance (in bit/s).
@item -minrate bitrate
-Set min video bitrate tolerance (in kbit/s).
+Set min video bitrate tolerance (in bit/s).
@item -bufsize size
-Set rate control buffer size (in kbit).
-@item -vcodec codec
+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
+@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
+@item -passlogfile file
Set two pass logfile name to @var{file}.
@end table
@section Advanced Video Options
@table @option
-@item -g gop_size
+@item -g gop_size
Set the group of pictures size.
-@item -intra
+@item -intra
Use only intra frames.
-@item -qscale q
+@item -qscale q
Use fixed video quantiser scale (VBR).
-@item -qmin q
+@item -qmin q
minimum video quantiser scale (VBR)
-@item -qmax q
+@item -qmax q
maximum video quantiser scale (VBR)
-@item -qdiff q
+@item -qdiff q
maximum difference between the quantiser scales (VBR)
-@item -qblur blur
+@item -qblur blur
video quantiser scale blur (VBR)
-@item -qcomp compression
+@item -qcomp compression
video quantiser scale compression (VBR)
@item -rc_init_cplx complexity
@item 0
FF_IDCT_AUTO (default)
@item 1
-FF_IDCT_INT
+FF_IDCT_INT
@item 2
-FF_IDCT_SIMPLE
+FF_IDCT_SIMPLE
@item 3
-FF_IDCT_SIMPLEMMX
+FF_IDCT_SIMPLEMMX
@item 4
-FF_IDCT_LIBMPEG2MMX
+FF_IDCT_LIBMPEG2MMX
@item 5
-FF_IDCT_PS2
+FF_IDCT_PS2
@item 6
-FF_IDCT_MLIB
+FF_IDCT_MLIB
@item 7
-FF_IDCT_ARM
+FF_IDCT_ARM
@item 8
-FF_IDCT_ALTIVEC
+FF_IDCT_ALTIVEC
@item 9
-FF_IDCT_SH4
+FF_IDCT_SH4
@item 10
-FF_IDCT_SIMPLEARM
+FF_IDCT_SIMPLEARM
@end table
@item -er n
Set error resilience to @var{n}.
@table @samp
-@item 1
+@item 1
FF_ER_CAREFUL (default)
@item 2
FF_ER_COMPLIANT
@item -deinterlace
Deinterlace pictures.
-@item -interlace
+@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.
@section Audio Options
@table @option
-@item -ar freq
+@item -ar freq
Set the audio sampling frequency (default = 44100 Hz).
-@item -ab bitrate
+@item -ab bitrate
Set the audio bitrate in kbit/s (default = 64).
@item -ac channels
Set the number of audio channels (default = 1).
@section Advanced options
@table @option
-@item -map file:stream
-Set input stream mapping.
+@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 -debug
Print specific debug info.
-@item -benchmark
+@item -benchmark
Add timings for benchmarking.
-@item -hex
+@item -hex
Dump each input packet.
@item -bitexact
Only use bit exact algorithms (for codec 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 -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.
+evaluator.
The following binary operators are available: @code{+}, @code{-},
@code{*}, @code{/}, @code{^}.
frames. An example is:
@example
-ffmpeg -g 3 -r 3 -t 10 -b 50 -s qcif -f rv10 /tmp/b.rm
+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
@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 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 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 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 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 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 @tab X
@end multitable
@code{X} means that encoding (resp. decoding) is 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 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 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 MJPEG @tab X @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 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 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: VP62
@item Theora @tab @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 @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 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 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 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 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 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 @tab X @tab
+@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.
@end multitable
@code{X} means that encoding (resp. decoding) is supported.
-See @url{http://www.mplayerhq.hu/~michael/codec-features.html} to
-get a precise comparison of the FFmpeg MPEG-4 codec compared to
-other implementations.
-
@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 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
@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 RA144 @tab @tab X
@tab Real 14400 bit/s codec
@item RA288 @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
@end multitable
@code{X} means that encoding (resp. decoding) is supported.
@section BSD
+BSD make will not build FFmpeg, you need to install and use GNU Make
+(@file{gmake}).
+
@section Windows
@subsection Native Windows compilation
directory. Edit the @file{sdl-config} script so that it gives the
correct SDL directory when invoked.
-@item Extract the current version of FFmpeg (the latest release version or
-the current CVS snapshot, whichever is recommended).
-
+@item Extract the current version of FFmpeg.
+
@item Start the MSYS shell (file @file{msys.bat}).
@item Change to the FFmpeg directory and follow
@end itemize
-Notes:
+Notes:
@itemize
@item The target @file{make wininstaller} can be used to create a
@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}.
+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
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 (the latest release version or
-the current CVS snapshot, whichever is recommended) and change to the
-FFmpeg directory.
+@item Extract the current version of FFmpeg and change to the FFmpeg directory.
@item Type the command
-@code{./configure --enable-shared --enable-memalign-hack} to configure and,
-if that didn't produce any errors, type @code{make} to build FFmpeg.
+@code{./configure --enable-shared --disable-static --enable-memalign-hack}
+to configure and, if that didn't 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},
Dependencies". Note that the names of the libraries have to be separated
using spaces.
-@item Now, select "C/C++ / Preprocessor" from the tree view. Select "Debug"
-in the "Configuration" combo box. Add @code{EMULATE_INTTYPES} to the
-"Preprocessor Definitions". (Note that the various preprocessor
-definitions have to be separated using semicolons.) Select "Release" in
-the "Configuration" combo box and, again, add @code{EMULATE_INTTYPES} to
-the "Preprocessor Definitions". (This has to be done separately because
-debug and release builds have different preprocessor definitions.)
-Finally, select "C/C++ / Code Generation" from the tree view. Select
+@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
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 don't 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 --enable-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 --enable-mingw32 --enable-memalign-hack --enable-shared --disable-static --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
+@end example
+
@section Mac OS X
@section BeOS
Old stuff:
-François Revol - revol at free dot fr - April 2002
+François Revol - revol at free dot fr - April 2002
-The configure script should guess the configuration itself,
+The configure script should guess the configuration itself,
however I still didn't 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
+that FFmpeg negates when returning. This ends up turning errors into
valid results, then crashes.
(To be fixed)
@chapter Developers Guide
@section API
-@itemize
+@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.
GCC statement expressions (@samp{(x = (@{ int y = 4; y; @})}).
@end itemize
-Indent size is 4. The TAB character should not be used.
-The presentation is the one specified by 'indent -i4 -kr'.
+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).
...
@end example
-fprintf and printf are forbidden in libavformat and libavcodec,
+fprintf and printf are forbidden in libavformat and libavcodec,
please use av_log() instead.
-@node CVS Policy
-@section CVS Policy
+@section Development Policy
@enumerate
-@item
+@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
+@item
You don't 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
+@item
Do not commit unrelated changes together, split them into self-contained
pieces.
@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)
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 (don't
+ then either do NOT change the indentation of the inner part within (don't
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
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 CVS log message. Since the ffmpeg-cvslog mailing list is publicly
+ 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
- Do NOT commit to code actively maintained by others without permission. Send
- a patch to ffmpeg-devel instead.
+ 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's 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 CVS commits
+ 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.
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
- Revert a commit ONLY in case of a big blunder like committing something not
- intended to be committed or committing a wrong file, the wrong version of a
- patch, CVS policy violation or broken code and you are going to recommit the
- right thing immediately.
-
- Never revert changes made a long time ago or buggy code. Fix it in the
- normal way instead.
@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.
@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.
-@subsection Renaming/moving files or content of files
- You CANNOT do that. Post a request for such a change to the mailing list
- Do NOT remove & readd a file - it will kill the changelog!!!!
-
@section Submitting patches
First, (@pxref{Coding Rules}) above if you didn't yet.
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
+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
Patches should be posted as base64 encoded attachments (or any other
encoding which ensures that the patch won't be trashed during
-transmission) to the ffmpeg-devel mailing list, see
-@url{http://www1.mplayerhq.hu/mailman/listinfo/ffmpeg-devel}
+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
@section Regression tests
-Before submitting a patch (or committing to CVS), you should at least
+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