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
+@section OpenCORE AMR
-AMR comes in two different flavors, wideband and narrowband. FFmpeg can make
-use of the AMR wideband (floating-point mode) and the AMR narrowband
-(floating-point mode) reference decoders and encoders.
+FFmpeg can make use of the OpenCORE libraries for AMR-NB
+decoding/encoding and AMR-WB decoding.
-Go to @url{http://www.penguin.cz/~utx/amr} and follow the instructions for
-installing the libraries. Then pass @code{--enable-libamr-nb} and/or
-@code{--enable-libamr-wb} to configure to enable the libraries.
+Go to @url{http://sourceforge.net/projects/opencore-amr/} and follow the instructions for
+installing the libraries. Then pass @code{--enable-libopencore-amrnb} and/or
+@code{--enable-libopencore-amrwb} to configure to enable the libraries.
-Note that libamr is copyrighted without any sort of license grant. This means
-that you can use it if you legally obtained it but you are not allowed to
-redistribute it in any way. @strong{Any FFmpeg binaries with libamr support
-you create are non-free and unredistributable!}
+Note that OpenCORE is under the Apache License 2.0 (see
+@url{http://www.apache.org/licenses/LICENSE-2.0} for details), which is
+incompatible with the LGPL version 2.1 and GPL version 2. You have to
+upgrade FFmpeg's license to LGPL version 3 (or if you have enabled
+GPL components, GPL version 3) to use it.
@chapter Supported File Formats and Codecs
-You can use the @code{-formats} option to have an exhaustive list.
+You can use the @code{-formats} and @code{-codecs} options to have an exhaustive list.
@section File Formats
@item Name @tab Encoding @tab Decoding @tab Comments
@item 4xm @tab @tab X
@tab 4X Technologies format, used in some games.
+@item 8088flex TMV @tab @tab X
+@item Adobe Filmstrip @tab X @tab X
@item Audio IFF (AIFF) @tab X @tab X
@item American Laser Games MM @tab @tab X
@tab Multimedia format used in games like Mad Dog McCree.
@tab Audio and video format used in some games by Beam Software.
@item Bethesda Softworks VID @tab @tab X
@tab Used in some games from Bethesda Softworks.
+@item Bink @tab @tab X
+ @tab Multimedia format used by many games.
@item Brute Force & Ignorance @tab @tab X
@tab Used in the game Flash Traffic: City of Angels.
@item Interplay C93 @tab @tab X
@tab Used in the game Cyberia from Interplay.
@item Delphine Software International CIN @tab @tab X
@tab Multimedia format used by Delphine Software games.
+@item CD+G @tab @tab X
+ @tab Video format used by CD+G karaoke disks
+@item Core Audio Format @tab @tab X
+ @tab Apple Core Audio Format
@item CRC testing format @tab X @tab
@item Creative Voice @tab X @tab X
@tab Created for the Sound Blaster Pro.
@item CRYO APC @tab @tab X
@tab Audio format used in some games by CRYO Interactive Entertainment.
@item D-Cinema audio @tab X @tab X
+@item Deluxe Paint Animation @tab @tab X
@item DV video @tab X @tab X
@item DXA @tab @tab X
@tab This format is used in the non-Windows version of the Feeble Files
@item id Quake II CIN video @tab @tab X
@item id RoQ @tab X @tab X
@tab Used in Quake III, Jedi Knight 2, other computer games.
+@item IEC61937 encapsulation @tab X @tab
@item IFF @tab @tab X
@tab Interchange File Format
@item Interplay MVE @tab @tab X
@tab Format used in various Interplay computer games.
+@item IV8 @tab @tab X
+ @tab A format generated by IndigoVision 8000 video server.
+@item IVF (On2) @tab @tab X
+ @tab A format used by libvpx
@item LMLM4 @tab @tab X
@tab Used by Linux Media Labs MPEG-4 PCI boards
@item Matroska @tab X @tab X
@item Matroska audio @tab X @tab
@item MAXIS XA @tab @tab X
@tab Used in Sim City 3000; file extension .xa.
+@item MD Studio @tab @tab X
@item Monkey's Audio @tab @tab X
@item Motion Pixels MVI @tab @tab X
@item MOV/QuickTime/MP4 @tab X @tab X
@item Ogg @tab X @tab X
@item TechnoTrend PVA @tab @tab X
@tab Used by TechnoTrend DVB PCI boards.
+@item QCP @tab @tab X
@item raw ADTS (AAC) @tab X @tab X
@item raw AC-3 @tab X @tab X
@item raw Chinese AVS video @tab @tab X
@item RL2 @tab @tab X
@tab Audio and video format used in some games by Entertainment Software Partners.
@item RPL/ARMovie @tab @tab X
+@item RTMP @tab X @tab X
+ @tab Output is performed by publishing stream to RTMP server
@item RTP @tab @tab X
-@item RTSP @tab @tab X
+@item RTSP @tab X @tab X
@item SDP @tab @tab X
@item Sega FILM/CPK @tab @tab X
@tab Used in many Sega Saturn console games.
@item Sony OpenMG (OMA) @tab @tab X
@tab Audio format used in Sony Sonic Stage and Sony Vegas.
@item Sony PlayStation STR @tab @tab X
+@item Sony Wave64 (W64) @tab @tab X
+@item SoX native format @tab X @tab X
@item SUN AU format @tab X @tab X
+@item Text files @tab @tab X
@item THP @tab @tab X
@tab Used on the Nintendo GameCube.
@item Tiertex Limited SEQ @tab @tab X
@item VC-1 test bitstream @tab X @tab X
@item WAV @tab X @tab X
@item WavPack @tab @tab X
+@item WebM @tab X @tab X
@item Wing Commander III movie @tab @tab X
@tab Multimedia format used in Origin's Wing Commander III computer game.
@item Westwood Studios audio @tab @tab X
@item Westwood Studios VQA @tab @tab X
@tab Multimedia format used in Westwood Studios games.
@item YUV4MPEG pipe @tab X @tab X
+@item Psygnosis YOP @tab @tab X
@end multitable
@code{X} means that encoding (resp. decoding) is supported.
@tab Only uncompressed GIFs are generated.
@item BMP @tab X @tab X
@tab Microsoft BMP image
+@item DPX @tab @tab X
+ @tab Digital Picture Exchange
@item JPEG @tab X @tab X
@tab Progressive JPEG is not supported.
@item JPEG 2000 @tab @tab E
@tab PAM is a PNM extension with alpha support.
@item PBM @tab X @tab X
@tab Portable BitMap image
-@item PCX @tab @tab X
+@item PCX @tab X @tab X
@tab PC Paintbrush
@item PGM @tab X @tab X
@tab Portable GrayMap image
@item PGMYUV @tab X @tab X
@tab PGM with U and V components in YUV 4:2:0
+@item PIC @tab @tab X
+ @tab Pictor/PC Paint
@item PNG @tab X @tab X
@tab 2/4 bpp not supported yet
@item PPM @tab X @tab X
@item Name @tab Encoding @tab Decoding @tab Comments
@item 4X Movie @tab @tab X
@tab Used in certain computer games.
+@item 8088flex TMV @tab @tab X
@item 8SVX exponential @tab @tab X
@item 8SVX fibonacci @tab @tab X
@item American Laser Games MM @tab @tab X
@tab Used in games like Mad Dog McCree.
@item AMV Video @tab @tab X
@tab Used in Chinese MP3 players.
+@item ANSI/ASCII art @tab @tab X
@item Apple MJPEG-B @tab @tab X
@item Apple QuickDraw @tab @tab X
@tab fourcc: qdrw
@tab fourcc: VCR1
@item ATI VCR2 @tab @tab X
@tab fourcc: VCR2
+@item Auravision Aura @tab @tab X
+@item Auravision Aura 2 @tab @tab X
@item Autodesk Animator Flic video @tab @tab X
@item Autodesk RLE @tab @tab X
@tab fourcc: AASC
@item Beam Software VB @tab @tab X
@item Bethesda VID video @tab @tab X
@tab Used in some games from Bethesda Softworks.
+@item Bink Video @tab @tab X
+ @tab Support for version 'b' is missing.
@item Brute Force & Ignorance @tab @tab X
@tab Used in the game Flash Traffic: City of Angels.
@item C93 video @tab @tab X
@tab Codec used in Cyberia game.
@item CamStudio @tab @tab X
@tab fourcc: CSCD
+@item CD+G @tab @tab X
+ @tab Video codec for CD+G karaoke disks
@item Chinese AVS video @tab @tab X
@tab AVS1-P2, JiZhun profile
@item Delphine Software International CIN video @tab @tab X
@item Creative YUV (CYUV) @tab @tab X
@item Dirac @tab E @tab E
@tab supported through external libdirac/libschroedinger libraries
+@item Deluxe Paint Animation @tab @tab X
@item DNxHD @tab X @tab X
@tab aka SMPTE VC3
@item Duck TrueMotion 1.0 @tab @tab X
@tab Codec originally used in Feeble Files game.
@item Electronic Arts CMV video @tab @tab X
@tab Used in NHL 95 game.
+@item Electronic Arts Madcow video @tab @tab X
@item Electronic Arts TGV video @tab @tab X
@item Electronic Arts TGQ video @tab @tab X
@item Electronic Arts TQI video @tab @tab X
@item Escape 124 @tab @tab X
-@item FFmpeg codec #1 @tab X @tab X
+@item FFmpeg video codec #1 @tab X @tab X
@tab experimental lossless codec (fourcc: FFV1)
@item Flash Screen Video v1 @tab X @tab X
@tab fourcc: FSV1
@tab Used in Quake II.
@item id RoQ video @tab X @tab X
@tab Used in Quake III, Jedi Knight 2, other computer games.
+@item IFF ILBM @tab @tab X
+ @tab IFF interlaved bitmap
+@item IFF ByteRun1 @tab @tab X
+ @tab IFF run length encoded bitmap
@item Intel H.263 @tab @tab X
@item Intel Indeo 2 @tab @tab X
@item Intel Indeo 3 @tab @tab X
+@item Intel Indeo 5 @tab @tab X
@item Interplay C93 @tab @tab X
@tab Used in the game Cyberia from Interplay.
@item Interplay MVE video @tab @tab X
@tab Used in Interplay .MVE files.
@item Karl Morton's video codec @tab @tab X
@tab Codec used in Worms games.
+@item Kega Game Video (KGV1) @tab @tab X
+ @tab Kega emulator screen capture codec.
@item LCL (LossLess Codec Library) MSZH @tab @tab X
@item LCL (LossLess Codec Library) ZLIB @tab E @tab E
@item LOCO @tab @tab X
@tab fourcc: VP50
@item On2 VP6 @tab @tab X
@tab fourcc: VP60,VP61,VP62
+@item VP8 @tab E @tab X
+ @tab fourcc: VP80, encoding supported through external library libvpx
@item planar RGB @tab @tab X
@tab fourcc: 8BPS
@item Q-team QPEG @tab @tab X
@tab fourcc: 'smc '
@item QuickTime video (RPZA) @tab @tab X
@tab fourcc: rpza
+@item R210 Quicktime Uncompressed RGB 10-bit @tab @tab X
@item Raw Video @tab X @tab X
@item RealVideo 1.0 @tab X @tab X
@item RealVideo 2.0 @tab X @tab X
@tab encoding supported through external library libtheora
@item Tiertex Limited SEQ video @tab @tab X
@tab Codec used in DOS CD-ROM FlashBack game.
+@item V210 Quicktime Uncompressed 4:2:2 10-bit @tab X @tab X
@item VMware Screen Codec / VMware Video @tab @tab X
@tab Codec used in videos captured by VMware.
@item Westwood Studios VQA (Vector Quantized Animation) video @tab @tab X
@item Winnov WNV1 @tab @tab X
@item WMV7 @tab X @tab X
@item YAMAHA SMAF @tab X @tab X
+@item Psygnosis YOP Video @tab @tab X
@item ZLIB @tab X @tab X
@tab part of LCL, encoder experimental
@item Zip Motion Blocks Video @tab X @tab X
@item ADPCM Westwood Studios IMA @tab @tab X
@tab Used in Westwood Studios games like Command and Conquer.
@item ADPCM Yamaha @tab X @tab X
-@item AMR-NB @tab E @tab E
- @tab supported through external library libamrnb
-@item AMR-WB @tab E @tab E
- @tab supported through external library libamrwb
+@item AMR-NB @tab E @tab X
+ @tab encoding supported through external library libopencore-amrnb
+@item AMR-WB @tab @tab E
+ @tab decoding supported through external library libopencore-amrwb
@item Apple lossless audio @tab X @tab X
@tab QuickTime fourcc 'alac'
+@item Atrac 1 @tab @tab X
@item Atrac 3 @tab @tab X
+@item Bink Audio @tab @tab X
+ @tab Used in Bink and Smacker files in many games.
@item Delphine Software International CIN audio @tab @tab X
@tab Codec used in Delphine Software International games.
@item COOK @tab @tab X
@tab Used in Sierra Online game audio files.
@item DPCM Sol @tab @tab X
@item DPCM Xan @tab @tab X
+ @tab Used in Origin's Wing Commander IV AVI files.
@item DSP Group TrueSpeech @tab @tab X
@item DV audio @tab @tab X
@item Enhanced AC-3 @tab @tab X
@item FLAC (Free Lossless Audio Codec) @tab X @tab IX
@item G.729 @tab @tab X
-@item GSM @tab E @tab E
- @tab supported through external library libgsm
-@item GSM Microsoft variant @tab E @tab E
- @tab supported through external library libgsm
+@item GSM @tab E @tab X
+ @tab encoding supported through external library libgsm
+@item GSM Microsoft variant @tab E @tab X
+ @tab encoding supported through external library libgsm
@item IMC (Intel Music Coder) @tab @tab X
@item MACE (Macintosh Audio Compression/Expansion) 3:1 @tab @tab X
@item MACE (Macintosh Audio Compression/Expansion) 6:1 @tab @tab X
@item MP2 (MPEG audio layer 2) @tab IX @tab IX
@item MP3 (MPEG audio layer 3) @tab E @tab IX
@tab encoding supported through external library LAME, ADU MP3 and MP3onMP4 also supported
+@item MPEG-4 Audio Lossless Coding (ALS) @tab @tab X
@item Musepack SV7 @tab @tab X
@item Musepack SV8 @tab @tab X
@item Nellymoser Asao @tab X @tab X
@item PCM signed 24-bit little-endian @tab X @tab X
@item PCM signed 32-bit big-endian @tab X @tab X
@item PCM signed 32-bit little-endian @tab X @tab X
+@item PCM signed 16/20/24-bit big-endian in MPEG-TS @tab @tab X
@item PCM unsigned 8-bit @tab X @tab X
@item PCM unsigned 16-bit big-endian @tab X @tab X
@item PCM unsigned 16-bit little-endian @tab X @tab X
@item QCELP / PureVoice @tab @tab X
@item QDesign Music Codec 2 @tab @tab X
@tab There are still some distortions.
-@item RealAudio 1.0 (14.4K) @tab @tab X
+@item RealAudio 1.0 (14.4K) @tab X @tab X
@tab Real 14400 bit/s codec
@item RealAudio 2.0 (28.8K) @tab @tab X
@tab Real 28800 bit/s codec
@item RealAudio 3.0 (dnet) @tab IX @tab X
@tab Real low bitrate AC-3 codec
+@item RealAudio SIPR / ACELP.NET @tab @tab X
@item Shorten @tab @tab X
@item Sierra VMD audio @tab @tab X
@tab Used in Sierra VMD files.
@item True Audio (TTA) @tab @tab X
@item TrueHD @tab @tab X
@tab Used in HD-DVD and Blu-Ray discs.
+@item TwinVQ (VQF flavor) @tab @tab X
@item Vorbis @tab E @tab X
- @ A native but very primitive encoder exists.
+ @tab A native but very primitive encoder exists.
@item WavPack @tab @tab X
@item Westwood Audio (SND1) @tab @tab X
@item Windows Media Audio 1 @tab X @tab X
@item Windows Media Audio 2 @tab X @tab X
- @tab Used in Origin's Wing Commander IV AVI files.
+@item Windows Media Audio Pro @tab @tab X
+@item Windows Media Audio Voice @tab @tab X
@end multitable
@code{X} means that encoding (resp. decoding) is supported.
@item SSA/ASS @tab X @tab X
@item DVB @tab X @tab X @tab X @tab X
@item DVD @tab X @tab X @tab X @tab X
-@item XSUB @tab @tab @tab @tab X
+@item PGS @tab @tab @tab @tab X
+@item XSUB @tab @tab @tab X @tab X
@end multitable
@code{X} means that the feature is supported.
@item file @tab X
@item Gopher @tab X
@item HTTP @tab X
+@item MMS @tab X
@item pipe @tab X
@item RTP @tab X
@item TCP @tab X
@multitable @columnfractions .4 .1 .1
@item Name @tab Input @tab Output
@item ALSA @tab X @tab X
-@item BEOS audio @tab X @tab X
@item BKTR @tab X @tab
@item DV1394 @tab X @tab
+@item JACK @tab X @tab
@item LIBDC1394 @tab X @tab
@item OSS @tab X @tab X
@item Video4Linux @tab X @tab
@chapter Platform Specific information
-@section BSD
+@section DOS
+
+Using a cross-compiler is preferred for various reasons.
+
+@subsection DJGPP
+
+FFmpeg cannot be compiled because of broken system headers, add
+@code{--extra-cflags=-U__STRICT_ANSI__} to the configure options as a
+workaround.
+
+@section OS/2
+
+For information about compiling FFmpeg on OS/2 see
+@url{http://www.edm2.com/index.php/FFmpeg}.
+
+@section Unix-like
+
+Some parts of FFmpeg cannot be built with version 2.15 of the GNU
+assembler which is still provided by a few AMD64 distributions. To
+make sure your compiler really uses the required version of gas
+after a binutils upgrade, run:
+
+@example
+$(gcc -print-prog-name=as) --version
+@end example
+
+If not, then you should install a different compiler that has no
+hard-coded path to gas. In the worst case pass @code{--disable-asm}
+to configure.
+
+@subsection BSD
BSD make will not build FFmpeg, you need to install and use GNU Make
(@file{gmake}).
+@subsubsection FreeBSD
+
+FreeBSD will not compile out-of-the-box due to broken system headers.
+Passing @code{--extra-cflags=-D__BSD_VISIBLE} to configure will work
+around the problem. This may have unexpected sideeffects, so use it at
+your own risk. If you care about FreeBSD, please make an attempt at
+getting the system headers fixed.
+
+@subsection (Open)Solaris
+
+GNU Make is required to build FFmpeg, so you have to invoke (@file{gmake}),
+standard Solaris Make will not work. When building with a non-c99 front-end
+(gcc, generic suncc) add either @code{--extra-libs=/usr/lib/values-xpg6.o}
+or @code{--extra-libs=/usr/lib/64/values-xpg6.o} to the configure options
+since the libc is not c99-compliant by default. The probes performed by
+configure may raise an exception leading to the death of configure itself
+due to a bug in the system shell. Simply invoke a different shell such as
+bash directly to work around this:
+
+@example
+bash ./configure
+@end example
+
+@subsection Darwin (MacOS X, iPhone)
+
+MacOS X on PowerPC or ARM (iPhone) requires a preprocessor from
+@url{http://github.com/yuvi/gas-preprocessor} to build the optimized
+assembler functions.
+
@section Windows
To get help and instructions for building FFmpeg under Windows, check out
@item mingw-runtime 3.15
@end itemize
-You will also need to pass @code{-fno-common} to the compiler to work around
+FFmpeg automatically passes @code{-fno-common} to the compiler to work around
a GCC bug (see @url{http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37216}).
Within the MSYS shell, configure and make with:
@example
-./configure --enable-memalign-hack --extra-cflags=-fno-common
+./configure --enable-memalign-hack
make
make install
@end example
@itemize
+@item Building natively using MSYS can be sped up by disabling implicit rules
+in the Makefile by calling @code{make -r} instead of plain @code{make}. This
+speed up is close to non-existent for normal one-off builds and is only
+noticeable when running make for a second time (for example in
+@code{make install}).
+
@item In order to compile FFplay, you must have the MinGW development library
of SDL. Get it from @url{http://www.libsdl.org}.
Edit the @file{bin/sdl-config} script so that it points to the correct prefix
@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 MSVC++ has already created for you. For example, you can copy
-@file{output_example.c} from the FFmpeg distribution.
+@file{libavformat/output-example.c} from the FFmpeg distribution.
@item Open the "Project / Properties" dialog box. In the "Configuration"
combo box, select "All Configurations" so that the changes you make will
@subsection Compilation under Cygwin
-The main issue with the 1.5.x Cygwin versions is that newlib, its C library,
-does not contain llrint(). You need to upgrade to the unstable 1.7.x versions,
-or leverage the implementation in MinGW (as explained below).
+Please use Cygwin 1.7.x as the obsolete 1.5.x Cygwin versions lack
+llrint() in its C library.
-Just install your Cygwin with all the "Base" packages, plus the
+Install your Cygwin with all the "Base" packages, plus the
following "Devel" ones:
@example
-binutils, gcc-core, make, subversion, mingw-runtime, diffutils
+binutils, gcc4-core, make, subversion, mingw-runtime, texi2html
@end example
-The experimental gcc4 package is still buggy, hence please
-use the official gcc 3.4.4 or a 4.2.x compiled from source by yourself.
-
-Install the current binutils-20080624-2 as they work fine (the old
-binutils-20060709-1 proved buggy on shared builds).
-
-Then create a small library that just contains llrint():
-
+And the following "Utils" one:
@example
-ar x /usr/lib/mingw/libmingwex.a llrint.o
-ar cq /usr/local/lib/libllrint.a llrint.o
+diffutils
@end example
Then run
@example
-./configure --enable-static --disable-shared --extra-ldflags='-L /usr/local/lib' --extra-libs='-l llrint'
+./configure --enable-static --disable-shared
@end example
-to make a static build or
+to make a static build.
+
+The current @code{gcc4-core} package is buggy and needs this flag to build
+shared libraries:
@example
-./configure --enable-shared --disable-static --extra-ldflags='-L /usr/local/lib' --extra-libs='-l llrint'
+./configure --enable-shared --disable-static --extra-cflags=-fno-reorder-functions
@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:
@example
(@url{http://sourceware.org/cygwinports/}) :
@example
-yasm, libSDL-devel, libdirac-devel, libfaac-devel, libfaad-devel, libgsm-devel,
+yasm, libSDL-devel, libdirac-devel, libfaac-devel, libgsm-devel,
libmp3lame-devel, libschroedinger1.0-devel, speex-devel, libtheora-devel,
libxvidcore-devel
@end example
./configure --target-os=mingw32 --enable-memalign-hack --enable-shared --disable-static --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
@end example
-@section BeOS
-
-BeOS support is broken in mysterious ways.
-
-@section OS/2
-
-For information about compiling FFmpeg on OS/2 see
-@url{http://www.edm2.com/index.php/FFmpeg}.
-
-@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.
-
-The main priority in FFmpeg is simplicity and small code size in order to
-minimize the bug count.
-
-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.
-
-Casts should be used only when necessary. Unneeded parentheses
-should also be avoided if they don't make the code easier to understand.
-
-@section Development Policy
-
-@enumerate
-@item
- Contributions should be licensed under the LGPL 2.1, including an
- "or any later version" clause, or the MIT license. GPL 2 including
- an "or any later version" clause is also acceptable, but LGPL is
- preferred.
-@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 no one 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.
- 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 or extension of an
- existing data structure).
- Incrementing the third component means a noteworthy binary compatible
- change (e.g. encoder bug fix that matters for the decoder).
-@item
- Compiler warnings indicate potential bugs or code with bad style. If a type of
- warning always points to correct and clean code, that warning should
- be disabled, not the code changed.
- Thus the remaining warnings can either be bugs or correct code.
- If it is a bug, the bug has to be fixed. If it is not, the code should
- be changed to not generate a warning unless that causes a slowdown
- or obfuscates the code.
-@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). We cannot read other diffs :-)
-
-Also please do not submit a patch which contains several unrelated changes.
-Split it into separate, self-contained pieces. This does not mean splitting
-file by file. Instead, make the patch as small as possible while still
-keeping it as a logical unit that contains an individual change, even
-if it spans multiple files. This makes reviewing your patches much easier
-for us and greatly increases your chances of getting your patch applied.
-
-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 a separate mail,
-do not attach several unrelated patches to the same mail.
-
-@section New codecs or formats checklist
-
-@enumerate
-@item
- Did you use av_cold for codec initialization and close functions?
-@item
- Did you add a long_name under NULL_IF_CONFIG_SMALL to the AVCodec or
- AVInputFormat/AVOutputFormat struct?
-@item
- Did you bump the minor version number in @file{avcodec.h} or
- @file{avformat.h}?
-@item
- Did you register it in @file{allcodecs.c} or @file{allformats.c}?
-@item
- Did you add the CodecID to @file{avcodec.h}?
-@item
- If it has a fourcc, did you add it to @file{libavformat/riff.c},
- even if it is only a decoder?
-@item
- Did you add a rule to compile the appropriate files in the Makefile?
- Remember to do this even if you're just adding a format to a file that is
- already being compiled by some other rule, like a raw demuxer.
-@item
- Did you add an entry to the table of supported formats or codecs in the
- documentation?
-@item
- Did you add an entry in the Changelog?
-@item
- If it depends on a parser or a library, did you add that dependency in
- configure?
-@item
- Did you "svn add" the appropriate files before commiting?
-@end enumerate
-
-@section patch submission checklist
-
-@enumerate
-@item
- Do the regression tests pass with the patch applied?
-@item
- Does @code{make checkheaders} 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
- Did you test your decoder or demuxer against damaged data? If no, see
- tools/trasher and the noise bitstream filter. Your decoder or demuxer
- should not crash or end in a (near) infinite loop when fed damaged data.
-@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?
- Note please do not attach samples >100k to mails but rather provide a
- URL, you can upload to ftp://upload.ffmpeg.org
-@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
- Lines with similar content should be aligned vertically when doing so
- improves readability.
-@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
projects / ffmpeg / blobdiff