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diff --git a/contrib/ffmpeg/doc/general.texi b/contrib/ffmpeg/doc/general.texi new file mode 100644 index 000000000..8fc27d603 --- /dev/null +++ b/contrib/ffmpeg/doc/general.texi @@ -0,0 +1,985 @@ +\input texinfo @c -*- texinfo -*- + +@settitle General Documentation +@titlepage +@sp 7 +@center @titlefont{General Documentation} +@sp 3 +@end titlepage + + +@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, 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. + +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. + +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!} + + +@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 +@item AVM2 (Flash 9) @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 X @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. +@item Monkey's Audio @tab @tab X +@item SIFF @tab @tab X +@tab Audio and video format used in some games by Beam Software +@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 X @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 X @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 X @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. +@item AMV @tab @tab X @tab Used in Chinese MP3 players. +@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 X @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 AMV IMA ADPCM @tab @tab X +@tab Used in AMV files +@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 SV7 and SV8 are supported +@item DT$ Coherent Audio @tab @tab X +@item ATRAC 3 @tab @tab X +@item Monkey's Audio @tab @tab X @tab Only versions 3.97-3.99 are supported +@item Nellymoser ASAO @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 building FFmpeg under Windows, check out +the FFmpeg Windows Help Forum at +@url{http://arrozcru.no-ip.org/ffmpeg/}. + +@subsection Native Windows compilation + +FFmpeg can be built to run natively on Windows using the MinGW tools. Install +the current versions of MSYS and MinGW from @url{http://www.mingw.org/}. Also +install the coreutils package. You can find detailed installation +instructions in the download section and the FAQ. + +Within the MSYS shell, configure and make with: + +@example +./configure --enable-memalign-hack +make +make install +@end example + +This will install @file{ffmpeg.exe} along with many other development files +to @file{/usr/local}. You may specify another install path using the +@code{--prefix} option in @file{configure}. + +Notes: + +@itemize + +@item Use at least bash 3.1. Older versions are known to fail on the +configure script. + +@item In order to compile vhooks, you must have a POSIX-compliant libdl in +your MinGW system. Get dlfcn-win32 from +@url{http://code.google.com/p/dlfcn-win32}. + +@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 +where SDL was installed. Verify that @file{sdl-config} can be launched from +the MSYS command line. + +@item The target @code{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 libavutil, libavcodec and libavformat as DLLs. + +@end itemize + +@subsection Microsoft Visual C++ compatibility + +As stated in the FAQ, FFmpeg will not compile under MSVC++. However, if you +want to use the libav* libraries in your own applications, you can still +compile those applications using MSVC++. But the libav* libraries you link +to @emph{must} be built with MinGW. However, you will not be able to debug +inside the libav* libraries, since MSVC++ does not recognize the debug +symbols generated by GCC. +We strongly recommend you to move over from MSVC++ to MinGW tools. + +This description of how to use the FFmpeg libraries with MSVC++ is based on +Microsoft Visual C++ 2005 Express Edition. If you have a different version, +you might have to modify the procedures slightly. + +@subsubsection Using static libraries + +Assuming you have just built and installed FFmpeg in @file{/usr/local}. + +@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 MSVC++ has already created for you. For example, you can copy +@file{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 +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 path where the FFmpeg includes were +installed (i.e. @file{c:\msys\1.0\local\include}). + +@item Still in the "Project / Properties" dialog box, select +"Linker / General" from the tree view and edit the +"Additional Library Directories" setting to contain the @file{lib} +directory where FFmpeg was installed (i.e. @file{c:\msys\1.0\local\lib}), +the directory where MinGW libs are installed (i.e. @file{c:\mingw\lib}), +and the directory where MinGW's GCC libs are installed +(i.e. @file{C:\mingw\lib\gcc\mingw32\4.2.1-sjlj}). Then select +"Linker / Input" from the tree view, and add the files @file{libavformat.a}, +@file{libavcodec.a}, @file{libavutil.a}, @file{libmingwex.a}, +@file{libgcc.a}, and any other libraries you used (i.e. @file{libz.a}) +to the end of "Additional Dependencies". + +@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. + +@item MSVC++ lacks some C99 header files that are fundamental for FFmpeg. +Get msinttypes from @url{http://code.google.com/p/msinttypes/downloads/list} +and install it in MSVC++'s include directory +(i.e. @file{C:\Program Files\Microsoft Visual Studio 8\VC\include}). + +@item MSVC++ also does not understand the @code{inline} keyword used by +FFmpeg, so you must add this line before @code{#include}ing libav*: +@example +#define inline _inline +@end example + +@item If you used @file{output_example.c} as your sample application, +you will have to edit the @code{#include}s to point to the files which +are under the @file{ffmpeg} directory (i.e. @code{<ffmpeg/avformat.h>}). + +@item Build your application, everything should work. + +@end enumerate + +@subsubsection Using shared libraries + +This is how to create DLL and LIB files that are compatible with MSVC++: + +@enumerate + +@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}: + +@example +call "C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat" +@end example + +Alternatively, you may start the @file{Visual Studio 2005 Command Prompt}, +and run @file{c:\msys\1.0\msys.bat} from there. + +@item Within the MSYS shell, run @code{lib.exe}. If you get a help message +from @file{Microsoft (R) Library Manager}, this means your environment +variables are set up correctly, the @file{Microsoft (R) Library Manager} +is on the path and will be used by FFmpeg to create +MSVC++-compatible import libraries. + +@item Build FFmpeg with + +@example +./configure --enable-shared --enable-memalign-hack +make +make install +@end example + +Your install path (@file{/usr/local/} by default) should now have the +necessary DLL and LIB files under the @file{bin} directory. + +@end enumerate + +To use those files with MSVC++, do the same as you would do with +the static libraries, as described above. But in Step 4, +you should only need to add the directory where the LIB files are installed +(i.e. @file{c:\msys\usr\local\bin}). This is not a typo, the LIB files are +installed in the @file{bin} directory. And instead of adding @file{libxx.a} +files, you should add @file{avcodec.lib}, @file{avformat.lib}, and +@file{avutil.lib}. There should be no need for @file{libmingwex.a}, +@file{libgcc.a}, and @file{wsock32.lib}, nor any other external library +statically linked into the DLLs. The @file{bin} directory contains a bunch +of DLL files, but the ones that are actually used to run your application +are the ones with a major version number in their filenames +(i.e. @file{avcodec-51.dll}). + +@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 + +The main issue with Cygwin is that newlib, its C library, does not +contain llrint(). However, it is possible to leverage the +implementation in MinGW. + +Just install your Cygwin with all the "Base" packages, plus the +following "Devel" ones: +@example +binutils, gcc-core, make, subversion, mingw-runtime +@end example + +Do not install binutils-20060709-1 (they are buggy on shared builds); +use binutils-20050610-1 instead. + +Then create a small library that just contains llrint(): + +@example +ar x /usr/lib/mingw/libmingwex.a llrint.o +ar cq /usr/local/lib/libllrint.a llrint.o +@end example + +Then run + +@example +./configure --enable-static --disable-shared --extra-ldflags='-L /usr/local/lib' --extra-libs='-l llrint' +@end example + +to make a static build or + +@example +./configure --enable-shared --disable-static --extra-ldflags='-L /usr/local/lib' --extra-libs='-l llrint' +@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 + +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 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 + 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 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? + Note please do not attach samples >100k to mails but rather provide a + URL, you can upload to ftp://upload.mplayerhq.hu +@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? +@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. +@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 |