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\input texinfo @c -*- texinfo -*-
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@settitle General Documentation
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@titlepage
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@sp 7
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@center @titlefont{General Documentation}
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@sp 3
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@end titlepage
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@chapter external libraries
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FFmpeg can be hooked up with a number of external libraries to add support
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for more formats. None of them are used by default, their use has to be
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explicitly requested by passing the appropriate flags to @file{./configure}.
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@section AMR
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AMR comes in two different flavors, wideband and narrowband. FFmpeg can make
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use of the AMR wideband (floating-point mode) and the AMR narrowband
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(floating-point mode) reference decoders and encoders.
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Go to @url{http://www.penguin.cz/~utx/amr} and follow the instructions for
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installing the libraries. Then pass @code{--enable-libamr-nb} and/or
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@code{--enable-libamr-wb} to configure to enable the libraries.
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Note that libamr is copyrighted without any sort of license grant. This means
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that you can use it if you legally obtained it but you are not allowed to
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redistribute it in any way. @strong{Any FFmpeg binaries with libamr support
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you create are non-free and unredistributable!}
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@chapter Supported File Formats and Codecs
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You can use the @code{-formats} option to have an exhaustive list.
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@section File Formats
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FFmpeg supports the following file formats through the @code{libavformat}
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library:
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@multitable @columnfractions .4 .1 .1 .4
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@item Name @tab Encoding @tab Decoding @tab Comments
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@item 4xm                       @tab   @tab X
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    @tab 4X Technologies format, used in some games.
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@item ADTS AAC audio            @tab X @tab X
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@item American Laser Games MM   @tab   @tab X
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    @tab Multimedia format used in games like Mad Dog McCree.
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@item ASF                       @tab X @tab X
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@item AVI                       @tab X @tab X
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@item AVM2 (Flash 9)            @tab X @tab X
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    @tab Only embedded audio is decoded.
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@item AVS                       @tab   @tab X
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    @tab Multimedia format used by the Creature Shock game.
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@item Bethsoft VID              @tab   @tab X
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    @tab Used in some games from Bethesda Softworks.
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@item BFI                       @tab   @tab X
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    @tab Brute Force & Ignorance, used in Flash Traffic: City of Angels.
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@item C93                       @tab   @tab X
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    @tab Used in the game Cyberia from Interplay.
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@item CIN                       @tab   @tab X
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    @tab Multimedia format used by Delphine Software games.
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@item Creative VOC              @tab X @tab X
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    @tab Created for the Sound Blaster Pro.
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@item CRYO APC                  @tab   @tab X
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    @tab Audio format used in some games by CRYO Interactive Entertainment.
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@item DV                        @tab X @tab X
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@item DXA                       @tab   @tab X
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    @tab This format is used in the non-Windows version of the Feeble Files
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         game and different game cutscenes repacked for use with ScummVM.
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@item Electronic Arts Multimedia  @tab    @tab X
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    @tab Used in various EA games; files have extensions like WVE and UV2.
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@item FLIC                      @tab   @tab X
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    @tab .fli/.flc files
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@item FLV                       @tab X @tab X
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    @tab Macromedia Flash video files
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@item FunCom ISS                @tab   @tab X
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    @tab Audio format used in various games from FunCom like The Longest Journey.
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@item GXF                       @tab X @tab X
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    @tab General eXchange Format SMPTE 360M, used by Thomson Grass Valley
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         playout servers.
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@item id Cinematic              @tab   @tab X
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    @tab Used in Quake II.
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@item id RoQ                    @tab X @tab X
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    @tab Used in Quake III, Jedi Knight 2, other computer games.
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@item IFF                       @tab   @tab X
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    @tab Interchange File Format
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@item Interplay MVE             @tab   @tab X
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    @tab Format used in various Interplay computer games.
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@item LMLM4                     @tab   @tab X
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    @tab Used by Linux Media Labs MPEG-4 PCI boards
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@item Matroska                  @tab X @tab X
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@item MAXIS EA XA               @tab   @tab X
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    @tab Used in Sim City 3000; file extension .xa.
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@item Monkey's Audio            @tab   @tab X
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@item Motion Pixels MVI         @tab   @tab X
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@item MOV/QuickTime             @tab X @tab X
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@item MPEG audio                @tab X @tab X
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@item MPEG-1 systems            @tab X @tab X
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    @tab muxed audio and video
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@item MPEG-2 PS                 @tab X @tab X
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    @tab also known as @code{VOB} file
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@item MPEG-2 TS                 @tab   @tab X
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    @tab also known as DVB Transport Stream
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@item MPEG-4                    @tab X @tab X
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    @tab MPEG-4 is a variant of QuickTime.
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@item MSN TCP webcam            @tab   @tab X
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    @tab Used by MSN Messenger webcam streams.
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@item MXF                       @tab X @tab X
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    @tab Material eXchange Format SMPTE 377M, used by D-Cinema, broadcast industry.
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@item Nullsoft Video            @tab   @tab X
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@item NUT                       @tab X @tab X
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    @tab NUT Open Container Format
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@item OMA                       @tab   @tab X
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    @tab Audio format used in Sony Sonic Stage and Sony Vegas.
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@item PlayStation STR           @tab   @tab X
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@item PVA                       @tab   @tab X
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    @tab Used by TechnoTrend DVB PCI boards.
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@item raw AC-3                  @tab X @tab X
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@item raw CRI ADX audio         @tab X @tab X
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@item raw MJPEG                 @tab X @tab X
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@item raw MPEG video            @tab X @tab X
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@item raw MPEG-4 video          @tab X @tab X
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@item raw PCM 8/16/32 bits, 32/64-bit floating point, mu-law/A-law @tab X  @tab  X
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@item raw Shorten audio         @tab    @tab  X
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@item RealMedia                 @tab X @tab X
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@item RL2                       @tab   @tab X
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    @tab Audio and video format used in some games by Entertainment Software Partners.
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@item Sega FILM/CPK             @tab   @tab X
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    @tab Used in many Sega Saturn console games.
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@item SEQ                       @tab   @tab X
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    @tab Tiertex .seq files used in the DOS CD-ROM version of the game Flashback.
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@item Sierra Online             @tab   @tab X
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    @tab .sol files used in Sierra Online games.
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@item Sierra VMD                @tab   @tab X
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    @tab Used in Sierra CD-ROM games.
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@item SIFF                      @tab   @tab X
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    @tab Audio and video format used in some games by Beam Software.
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@item Smacker                   @tab   @tab X
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    @tab Multimedia format used by many games.
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@item SUN AU format             @tab X @tab X
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@item THP                       @tab   @tab X
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    @tab Used on the Nintendo GameCube.
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@item WAV                       @tab X @tab X
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@item WC3 Movie                 @tab   @tab X
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    @tab Multimedia format used in Origin's Wing Commander III computer game.
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@item Westwood Studios VQA/AUD  @tab   @tab X
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    @tab Multimedia formats used in Westwood Studios games.
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@end multitable
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@code{X} means that encoding (resp. decoding) is supported.
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@section Image Formats
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FFmpeg can read and write images for each frame of a video sequence. The
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following image formats are supported:
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@multitable @columnfractions .4 .1 .1 .4
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@item Name @tab Encoding @tab Decoding @tab Comments
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@item .Y.U.V       @tab X @tab X @tab one raw file per component
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@item animated GIF @tab X @tab X @tab Only uncompressed GIFs are generated.
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@item JPEG         @tab X @tab X @tab Progressive JPEG is not supported.
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@item PAM          @tab X @tab X @tab PAM is a PNM extension with alpha support.
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@item PCX          @tab   @tab X @tab PC Paintbrush
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@item PGM, PPM     @tab X @tab X
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@item PGMYUV       @tab X @tab X @tab PGM with U and V components in YUV 4:2:0
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@item PNG          @tab X @tab X @tab 2/4 bpp not supported yet
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@item PTX          @tab   @tab X @tab V.Flash PTX format
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@item RAS          @tab   @tab X @tab Sun Rasterfile
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@item SGI          @tab X @tab X @tab SGI RGB image format
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@item Targa        @tab   @tab X @tab Targa (.TGA) image format
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@item TIFF         @tab X @tab X @tab YUV, JPEG and some extension is not supported yet.
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@end multitable
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@code{X} means that encoding (resp. decoding) is supported.
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@section Video Codecs
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@multitable @columnfractions .4 .1 .1 .4
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@item Name @tab Encoding @tab Decoding @tab Comments
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@item 4X Video               @tab     @tab  X
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    @tab Used in certain computer games.
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@item American Laser Games Video  @tab    @tab X
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    @tab Used in games like Mad Dog McCree.
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@item AMV                    @tab     @tab  X
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    @tab Used in Chinese MP3 players.
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@item Apple Animation        @tab  X  @tab  X
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    @tab fourcc: 'rle '
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@item Apple Graphics         @tab     @tab  X
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    @tab fourcc: 'smc '
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@item Apple MJPEG-B          @tab     @tab  X
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@item Apple QuickDraw        @tab     @tab  X
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    @tab fourcc: qdrw
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@item Apple Video            @tab     @tab  X
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    @tab fourcc: rpza
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@item Asus v1                @tab  X  @tab  X
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    @tab fourcc: ASV1
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@item Asus v2                @tab  X  @tab  X
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    @tab fourcc: ASV2
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@item ATI VCR1               @tab     @tab  X
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    @tab fourcc: VCR1
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@item ATI VCR2               @tab     @tab  X
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    @tab fourcc: VCR2
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@item Autodesk RLE           @tab     @tab  X
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    @tab fourcc: AASC
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@item AVID DNxHD             @tab   X @tab  X
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    @tab aka SMPTE VC3
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@item AVS video              @tab     @tab  X
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    @tab Video encoding used by the Creature Shock game.
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@item Bethsoft VID           @tab     @tab  X
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    @tab Used in some games from Bethesda Softworks.
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@item C93 video              @tab     @tab  X
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    @tab Codec used in Cyberia game.
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@item CamStudio              @tab     @tab  X
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    @tab fourcc: CSCD
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@item Cin video              @tab     @tab  X
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    @tab Codec used in Delphine Software games.
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@item Cinepak                @tab     @tab  X
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@item Cirrus Logic AccuPak   @tab     @tab  X
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    @tab fourcc: CLJR
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@item Creative YUV           @tab     @tab  X
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    @tab fourcc: CYUV
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@item Dirac                  @tab  E  @tab  E
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    @tab supported through external libdirac/libschroedinger libraries
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@item Duck TrueMotion v1     @tab     @tab  X
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    @tab fourcc: DUCK
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@item Duck TrueMotion v2     @tab     @tab  X
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    @tab fourcc: TM20
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@item DV                     @tab  X  @tab  X
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@item DXA Video              @tab     @tab  X
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    @tab Codec originally used in Feeble Files game.
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@item Electronic Arts CMV    @tab     @tab  X
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    @tab Used in NHL 95 game.
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@item Electronic Arts TGV    @tab     @tab  X
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@item Electronic Arts TGQ    @tab     @tab  X
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@item FFmpeg Video 1         @tab  X  @tab  X
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    @tab experimental lossless codec (fourcc: FFV1)
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@item Flash Screen Video     @tab  X  @tab  X
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    @tab fourcc: FSV1
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@item FLIC video             @tab     @tab  X
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@item FLV                    @tab  X  @tab  X
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    @tab Sorenson H.263 used in Flash
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@item Fraps FPS1             @tab     @tab  X
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@item H.261                  @tab  X  @tab  X
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@item H.263(+)               @tab  X  @tab  X
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    @tab also known as RealVideo 1.0
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@item H.264                  @tab  E  @tab  X
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    @tab encoding supported through external library libx264
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@item HuffYUV                @tab  X  @tab  X
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@item IBM Ultimotion         @tab     @tab  X
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    @tab fourcc: ULTI
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@item id Cinematic video     @tab     @tab  X
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    @tab Used in Quake II.
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@item id RoQ                 @tab  X  @tab  X
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    @tab Used in Quake III, Jedi Knight 2, other computer games.
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@item Intel Indeo 3          @tab     @tab  X
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@item Interplay Video        @tab     @tab  X
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    @tab Used in Interplay .MVE files.
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@item JPEG-LS                @tab  X  @tab  X
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    @tab fourcc: MJLS, lossless and near-lossless is supported.
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@item KMVC                   @tab     @tab  X
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    @tab Codec used in Worms games.
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@item LOCO                   @tab     @tab  X
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@item lossless MJPEG         @tab  X  @tab  X
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@item Microsoft RLE          @tab     @tab  X
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@item Microsoft Video-1      @tab     @tab  X
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@item Mimic                  @tab     @tab  X
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    @tab Used in MSN Messenger Webcam streams.
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@item Miro VideoXL           @tab     @tab  X
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    @tab fourcc: VIXL
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@item MJPEG                  @tab  X  @tab  X
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@item Motion Pixels Video    @tab     @tab  X
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@item MPEG-1                 @tab  X  @tab  X
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@item MPEG-2                 @tab  X  @tab  X
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@item MPEG-4                 @tab  X  @tab  X
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@item MSMPEG4 V1             @tab  X  @tab  X
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@item MSMPEG4 V2             @tab  X  @tab  X
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@item MSMPEG4 V3             @tab  X  @tab  X
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@item MSZH                   @tab     @tab  X
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    @tab Part of LCL
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@item On2 VP3                @tab     @tab  X
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    @tab still experimental
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@item On2 VP5                @tab     @tab  X
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    @tab fourcc: VP50
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@item On2 VP6                @tab     @tab  X
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    @tab fourcc: VP60,VP61,VP62
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@item planar RGB             @tab     @tab  X
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    @tab fourcc: 8BPS
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@item QPEG                   @tab     @tab  X
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    @tab fourccs: QPEG, Q1.0, Q1.1
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@item RealVideo 1.0          @tab  X  @tab  X
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@item RealVideo 2.0          @tab  X  @tab  X
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@item RealVideo 3.0          @tab     @tab  X
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    @tab still far from ideal
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@item RealVideo 4.0          @tab     @tab  X
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@item Renderware TXD         @tab     @tab  X
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    @tab Texture dictionaries used by the Renderware Engine.
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@item RTjpeg                 @tab     @tab  X
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    @tab Video encoding used in NuppelVideo files.
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@item Smacker video          @tab     @tab  X
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    @tab Video encoding used in Smacker.
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@item Snow                   @tab  X  @tab  X
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    @tab experimental wavelet codec (fourcc: SNOW)
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@item Sony PlayStation MDEC  @tab     @tab  X
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@item Sorenson Video 1       @tab  X  @tab  X
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    @tab fourcc: SVQ1
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@item Sorenson Video 3       @tab     @tab  X
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    @tab fourcc: SVQ3
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@item Sunplus MJPEG          @tab     @tab  X
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    @tab fourcc: SP5X
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@item TechSmith Camtasia     @tab     @tab  X
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    @tab fourcc: TSCC
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@item Theora                 @tab  E  @tab  X
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    @tab encoding supported through external library libtheora
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@item THP                    @tab     @tab  X
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    @tab Used on the Nintendo GameCube.
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@item Tiertex Seq video      @tab     @tab  X
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    @tab Codec used in DOS CD-ROM FlashBack game.
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@item VC-1                   @tab     @tab  X
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@item VMD Video              @tab     @tab  X
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    @tab Used in Sierra VMD files.
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@item VMware Video           @tab     @tab  X
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    @tab Codec used in videos captured by VMware.
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@item Westwood VQA           @tab     @tab  X
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@item Winnov WNV1            @tab     @tab  X
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@item WMV7                   @tab  X  @tab  X
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@item WMV8                   @tab  X  @tab  X
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@item WMV9                   @tab     @tab  X
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    @tab not completely working
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@item Xan/WC3                @tab     @tab  X
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    @tab Used in Wing Commander III .MVE files.
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@item ZLIB                   @tab  X  @tab  X
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    @tab part of LCL, encoder experimental
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@item ZMBV                   @tab   X @tab  X
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    @tab Encoder works only in PAL8.
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@end multitable
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@code{X} means that encoding (resp. decoding) is supported.
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@code{E} means that support is provided through an external library.
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@section Audio Codecs
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@multitable @columnfractions .4 .1 .1 .4
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@item Name @tab Encoding @tab Decoding @tab Comments
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@item 4X IMA ADPCM           @tab     @tab  X
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@item 8SVX audio             @tab     @tab  X
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@item AAC                    @tab  E  @tab  X
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    @tab encoding supported through external library libfaac
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@item AC-3                   @tab IX  @tab IX
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@item AMR-NB                 @tab  E  @tab  E
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    @tab supported through external library libamrnb
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@item AMR-WB                 @tab  E  @tab  E
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    @tab supported through external library libamrwb
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@item AMV IMA ADPCM          @tab     @tab  X
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    @tab Used in AMV files
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@item Apple lossless audio   @tab  X  @tab  X
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    @tab QuickTime fourcc 'alac'
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@item Apple MACE 3           @tab     @tab  X
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@item Apple MACE 6           @tab     @tab  X
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@item ATRAC 3                @tab     @tab  X
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@item CD-ROM XA ADPCM        @tab     @tab  X
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@item Cin audio              @tab     @tab  X
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    @tab Codec used in Delphine Software International games.
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@item Creative ADPCM         @tab     @tab  X
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    @tab 16 -> 4, 8 -> 4, 8 -> 3, 8 -> 2
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@item CRI ADX ADPCM          @tab  X  @tab  X
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    @tab Used in Sega Dreamcast games.
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@item DSP Group TrueSpeech   @tab     @tab  X
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@item DTS Coherent Audio     @tab     @tab  X
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@item Duck DK3 IMA ADPCM     @tab     @tab  X
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    @tab Used in some Sega Saturn console games.
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@item Duck DK4 IMA ADPCM     @tab     @tab  X
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    @tab Used in some Sega Saturn console games.
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@item DV audio               @tab     @tab  X
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@item Electronic Arts ADPCM  @tab     @tab  X
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    @tab Used in various EA titles.
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@item Enhanced AC-3          @tab     @tab  X
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@item FLAC lossless audio    @tab IX  @tab  X
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@item G.726  ADPCM           @tab  X  @tab  X
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@item GSM                    @tab  E  @tab  E
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    @tab supported through external library libgsm
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@item GSM_MS                 @tab  E  @tab  E
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    @tab supported through external library libgsm
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@item id RoQ DPCM            @tab  X  @tab  X
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    @tab Used in Quake III, Jedi Knight 2, other computer games.
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@item Intel Music Coder      @tab     @tab  X
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@item Interplay MVE DPCM     @tab     @tab  X
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    @tab Used in various Interplay computer games.
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@item ISS IMA ADPCM          @tab     @tab  X
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    @tab Used in FunCom games.
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@item MAXIS EA ADPCM         @tab     @tab  X
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    @tab Used in Sim City 3000.
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@item Microsoft ADPCM        @tab  X  @tab  X
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@item MLP/TrueHD             @tab     @tab  X
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    @tab Used in DVD-Audio and Blu-Ray discs.
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@item Monkey's Audio         @tab     @tab  X
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    @tab Only versions 3.97-3.99 are supported.
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@item MPEG audio layer 3     @tab  E  @tab IX
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    @tab encoding supported through external library LAME
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@item MPEG audio layer 2     @tab IX  @tab IX
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@item MS IMA ADPCM           @tab  X  @tab  X
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@item Musepack               @tab     @tab  X
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    @tab SV7 and SV8 are supported.
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@item Nellymoser ASAO        @tab  X  @tab  X
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@item QCELP / PureVoice      @tab     @tab  X
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@item Qdesign QDM2           @tab     @tab  X
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    @tab There are still some distortions.
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@item QT IMA ADPCM           @tab  X  @tab  X
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@item RA144                  @tab     @tab  X
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    @tab Real 14400 bit/s codec
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@item RA288                  @tab     @tab  X
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    @tab Real 28800 bit/s codec
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@item RADnet                 @tab IX  @tab IX
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    @tab Real low bitrate AC-3 codec
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@item Real COOK              @tab     @tab  X
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    @tab All versions except 5.1 are supported.
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@item Shorten                @tab     @tab  X
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@item Sierra Online DPCM     @tab     @tab  X
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    @tab Used in Sierra Online game audio files.
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@item Smacker audio          @tab     @tab  X
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@item SMJPEG IMA ADPCM       @tab     @tab  X
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    @tab Used in certain Loki game ports.
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@item Sonic                  @tab  X  @tab  X
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    @tab experimental codec
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@item Sonic lossless         @tab  X  @tab  X
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    @tab experimental codec
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@item Speex                  @tab     @tab  E
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    @tab supported through external library libspeex
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@item THP ADPCM              @tab     @tab  X
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    @tab Used on the Nintendo GameCube.
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@item True Audio (TTA)       @tab     @tab  X
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@item Vorbis                 @tab  X  @tab  X
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@item WavPack                @tab     @tab  X
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@item Westwood Studios IMA ADPCM @tab     @tab  X
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    @tab Used in Westwood Studios games like Command and Conquer.
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@item WMA v1/v2              @tab  X  @tab  X
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@item Xan DPCM               @tab     @tab  X
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    @tab Used in Origin's Wing Commander IV AVI files.
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@end multitable
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@code{X} means that encoding (resp. decoding) is supported.
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@code{E} means that support is provided through an external library.
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@code{I} means that an integer-only version is available, too (ensures high
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performance on systems without hardware floating point support).
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@section Subtitle Formats
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@multitable @columnfractions .4 .1 .1 .1 .1 .1
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@item Name @tab Muxing @tab Demuxing @tab Encoding @tab Decoding @tab Rendering
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@item ASS/SSA      @tab X @tab X
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@item DVB          @tab X @tab X @tab X @tab X @tab X
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@item DVD          @tab X @tab X @tab X @tab X @tab X
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@end multitable
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@code{X} means that the feature is supported.
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@chapter Platform Specific information
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@section BSD
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BSD make will not build FFmpeg, you need to install and use GNU Make
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(@file{gmake}).
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@section Windows
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To get help and instructions for building FFmpeg under Windows, check out
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the FFmpeg Windows Help Forum at
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@url{http://ffmpeg.arrozcru.org/}.
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@subsection Native Windows compilation
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FFmpeg can be built to run natively on Windows using the MinGW tools. Install
476
the latest versions of MSYS and MinGW from @url{http://www.mingw.org/}.
477
You can find detailed installation
478
instructions in the download section and the FAQ.
479

    
480
FFmpeg does not build out-of-the-box with the packages the automated MinGW
481
installer provides. It also requires coreutils to be installed and many other
482
packages updated to the latest version. The minimum version for some packages
483
are listed below:
484

    
485
@itemize
486
@item bash 3.1
487
@item msys-make 3.81-2 (note: not mingw32-make)
488
@item w32api 3.13
489
@item mingw-runtime 3.15
490
@end itemize
491

    
492
You will also need to pass @code{-fno-common} to the compiler to work around
493
a GCC bug (see @url{http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37216}).
494

    
495
Within the MSYS shell, configure and make with:
496

    
497
@example
498
./configure --enable-memalign-hack --extra-cflags=-fno-common
499
make
500
make install
501
@end example
502

    
503
This will install @file{ffmpeg.exe} along with many other development files
504
to @file{/usr/local}. You may specify another install path using the
505
@code{--prefix} option in @file{configure}.
506

    
507
Notes:
508

    
509
@itemize
510

    
511
@item In order to compile vhooks, you must have a POSIX-compliant libdl in
512
your MinGW system. Get dlfcn-win32 from
513
@url{http://code.google.com/p/dlfcn-win32}.
514

    
515
@item In order to compile FFplay, you must have the MinGW development library
516
of SDL. Get it from @url{http://www.libsdl.org}.
517
Edit the @file{bin/sdl-config} script so that it points to the correct prefix
518
where SDL was installed. Verify that @file{sdl-config} can be launched from
519
the MSYS command line.
520

    
521
@item By using @code{./configure --enable-shared} when configuring FFmpeg,
522
you can build libavutil, libavcodec and libavformat as DLLs.
523

    
524
@end itemize
525

    
526
@subsection Microsoft Visual C++ compatibility
527

    
528
As stated in the FAQ, FFmpeg will not compile under MSVC++. However, if you
529
want to use the libav* libraries in your own applications, you can still
530
compile those applications using MSVC++. But the libav* libraries you link
531
to @emph{must} be built with MinGW. However, you will not be able to debug
532
inside the libav* libraries, since MSVC++ does not recognize the debug
533
symbols generated by GCC.
534
We strongly recommend you to move over from MSVC++ to MinGW tools.
535

    
536
This description of how to use the FFmpeg libraries with MSVC++ is based on
537
Microsoft Visual C++ 2005 Express Edition. If you have a different version,
538
you might have to modify the procedures slightly.
539

    
540
@subsubsection Using static libraries
541

    
542
Assuming you have just built and installed FFmpeg in @file{/usr/local}.
543

    
544
@enumerate
545

    
546
@item Create a new console application ("File / New / Project") and then
547
select "Win32 Console Application". On the appropriate page of the
548
Application Wizard, uncheck the "Precompiled headers" option.
549

    
550
@item Write the source code for your application, or, for testing, just
551
copy the code from an existing sample application into the source file
552
that MSVC++ has already created for you. For example, you can copy
553
@file{output_example.c} from the FFmpeg distribution.
554

    
555
@item Open the "Project / Properties" dialog box. In the "Configuration"
556
combo box, select "All Configurations" so that the changes you make will
557
affect both debug and release builds. In the tree view on the left hand
558
side, select "C/C++ / General", then edit the "Additional Include
559
Directories" setting to contain the path where the FFmpeg includes were
560
installed (i.e. @file{c:\msys\1.0\local\include}).
561
Do not add MinGW's include directory here, or the include files will
562
conflict with MSVC's.
563

    
564
@item Still in the "Project / Properties" dialog box, select
565
"Linker / General" from the tree view and edit the
566
"Additional Library Directories" setting to contain the @file{lib}
567
directory where FFmpeg was installed (i.e. @file{c:\msys\1.0\local\lib}),
568
the directory where MinGW libs are installed (i.e. @file{c:\mingw\lib}),
569
and the directory where MinGW's GCC libs are installed
570
(i.e. @file{C:\mingw\lib\gcc\mingw32\4.2.1-sjlj}). Then select
571
"Linker / Input" from the tree view, and add the files @file{libavformat.a},
572
@file{libavcodec.a}, @file{libavutil.a}, @file{libmingwex.a},
573
@file{libgcc.a}, and any other libraries you used (i.e. @file{libz.a})
574
to the end of "Additional Dependencies".
575

    
576
@item Now, select "C/C++ / Code Generation" from the tree view. Select
577
"Debug" in the "Configuration" combo box. Make sure that "Runtime
578
Library" is set to "Multi-threaded Debug DLL". Then, select "Release" in
579
the "Configuration" combo box and make sure that "Runtime Library" is
580
set to "Multi-threaded DLL".
581

    
582
@item Click "OK" to close the "Project / Properties" dialog box.
583

    
584
@item MSVC++ lacks some C99 header files that are fundamental for FFmpeg.
585
Get msinttypes from @url{http://code.google.com/p/msinttypes/downloads/list}
586
and install it in MSVC++'s include directory
587
(i.e. @file{C:\Program Files\Microsoft Visual Studio 8\VC\include}).
588

    
589
@item MSVC++ also does not understand the @code{inline} keyword used by
590
FFmpeg, so you must add this line before @code{#include}ing libav*:
591
@example
592
#define inline _inline
593
@end example
594

    
595
@item Build your application, everything should work.
596

    
597
@end enumerate
598

    
599
@subsubsection Using shared libraries
600

    
601
This is how to create DLL and LIB files that are compatible with MSVC++:
602

    
603
@enumerate
604

    
605
@item Add a call to @file{vcvars32.bat} (which sets up the environment
606
variables for the Visual C++ tools) as the first line of @file{msys.bat}.
607
The standard location for @file{vcvars32.bat} is
608
@file{C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat},
609
and the standard location for @file{msys.bat} is @file{C:\msys\1.0\msys.bat}.
610
If this corresponds to your setup, add the following line as the first line
611
of @file{msys.bat}:
612

    
613
@example
614
call "C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat"
615
@end example
616

    
617
Alternatively, you may start the @file{Visual Studio 2005 Command Prompt},
618
and run @file{c:\msys\1.0\msys.bat} from there.
619

    
620
@item Within the MSYS shell, run @code{lib.exe}. If you get a help message
621
from @file{Microsoft (R) Library Manager}, this means your environment
622
variables are set up correctly, the @file{Microsoft (R) Library Manager}
623
is on the path and will be used by FFmpeg to create
624
MSVC++-compatible import libraries.
625

    
626
@item Build FFmpeg with
627

    
628
@example
629
./configure --enable-shared --enable-memalign-hack
630
make
631
make install
632
@end example
633

    
634
Your install path (@file{/usr/local/} by default) should now have the
635
necessary DLL and LIB files under the @file{bin} directory.
636

    
637
@end enumerate
638

    
639
To use those files with MSVC++, do the same as you would do with
640
the static libraries, as described above. But in Step 4,
641
you should only need to add the directory where the LIB files are installed
642
(i.e. @file{c:\msys\usr\local\bin}). This is not a typo, the LIB files are
643
installed in the @file{bin} directory. And instead of adding @file{libxx.a}
644
files, you should add @file{avcodec.lib}, @file{avformat.lib}, and
645
@file{avutil.lib}. There should be no need for @file{libmingwex.a},
646
@file{libgcc.a}, and @file{wsock32.lib}, nor any other external library
647
statically linked into the DLLs. The @file{bin} directory contains a bunch
648
of DLL files, but the ones that are actually used to run your application
649
are the ones with a major version number in their filenames
650
(i.e. @file{avcodec-51.dll}).
651

    
652
@subsection Cross compilation for Windows with Linux
653

    
654
You must use the MinGW cross compilation tools available at
655
@url{http://www.mingw.org/}.
656

    
657
Then configure FFmpeg with the following options:
658
@example
659
./configure --target-os=mingw32 --cross-prefix=i386-mingw32msvc-
660
@end example
661
(you can change the cross-prefix according to the prefix chosen for the
662
MinGW tools).
663

    
664
Then you can easily test FFmpeg with Wine
665
(@url{http://www.winehq.com/}).
666

    
667
@subsection Compilation under Cygwin
668

    
669
The main issue with the 1.5.x Cygwin versions is that newlib, its C library,
670
does not contain llrint().  You need to upgrade to the unstable 1.7.x versions,
671
or leverage the implementation in MinGW (as explained below).
672

    
673
Just install your Cygwin with all the "Base" packages, plus the
674
following "Devel" ones:
675
@example
676
binutils, gcc-core, make, subversion, mingw-runtime, diffutils
677
@end example
678

    
679
The experimental gcc4 package is still buggy, hence please
680
use the official gcc 3.4.4 or a 4.2.x compiled from source by yourself.
681

    
682
Install the current binutils-20080624-2 as they work fine (the old
683
binutils-20060709-1 proved buggy on shared builds).
684

    
685
Then create a small library that just contains llrint():
686

    
687
@example
688
ar x /usr/lib/mingw/libmingwex.a llrint.o
689
ar cq /usr/local/lib/libllrint.a llrint.o
690
@end example
691

    
692
Then run
693

    
694
@example
695
./configure --enable-static --disable-shared  --extra-ldflags='-L /usr/local/lib' --extra-libs='-l llrint'
696
@end example
697

    
698
to make a static build or
699

    
700
@example
701
./configure --enable-shared --disable-static  --extra-ldflags='-L /usr/local/lib' --extra-libs='-l llrint'
702
@end example
703

    
704
to build shared libraries.
705

    
706
If you want to build FFmpeg with additional libraries, download Cygwin
707
"Devel" packages for Ogg and Vorbis from any Cygwin packages repository:
708
@example
709
libogg-devel, libvorbis-devel
710
@end example
711

    
712
These library packages are only available from Cygwin Ports
713
(@url{http://sourceware.org/cygwinports/}) :
714

    
715
@example
716
yasm, libSDL-devel, libdirac-devel, libfaac-devel, libfaad-devel, libgsm-devel,
717
libmp3lame-devel, libschroedinger1.0-devel, speex-devel, libtheora-devel,
718
libxvidcore-devel
719
@end example
720

    
721
The recommendation for libnut and x264 is to build them from source by
722
yourself, as they evolve too quickly for Cygwin Ports to be up to date.
723

    
724
@subsection Crosscompilation for Windows under Cygwin
725

    
726
With Cygwin you can create Windows binaries that do not need the cygwin1.dll.
727

    
728
Just install your Cygwin as explained before, plus these additional
729
"Devel" packages:
730
@example
731
gcc-mingw-core, mingw-runtime, mingw-zlib
732
@end example
733

    
734
and add some special flags to your configure invocation.
735

    
736
For a static build run
737
@example
738
./configure --target-os=mingw32 --enable-memalign-hack --enable-static --disable-shared --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
739
@end example
740

    
741
and for a build with shared libraries
742
@example
743
./configure --target-os=mingw32 --enable-memalign-hack --enable-shared --disable-static --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
744
@end example
745

    
746
@section BeOS
747

    
748
BeOS support is broken in mysterious ways.
749

    
750
@section OS/2
751

    
752
For information about compiling FFmpeg on OS/2 see
753
@url{http://www.edm2.com/index.php/FFmpeg}.
754

    
755
@chapter Developers Guide
756

    
757
@section API
758
@itemize @bullet
759
@item libavcodec is the library containing the codecs (both encoding and
760
decoding). Look at @file{libavcodec/apiexample.c} to see how to use it.
761

    
762
@item libavformat is the library containing the file format handling (mux and
763
demux code for several formats). Look at @file{ffplay.c} to use it in a
764
player. See @file{output_example.c} to use it to generate audio or video
765
streams.
766

    
767
@end itemize
768

    
769
@section Integrating libavcodec or libavformat in your program
770

    
771
You can integrate all the source code of the libraries to link them
772
statically to avoid any version problem. All you need is to provide a
773
'config.mak' and a 'config.h' in the parent directory. See the defines
774
generated by ./configure to understand what is needed.
775

    
776
You can use libavcodec or libavformat in your commercial program, but
777
@emph{any patch you make must be published}. The best way to proceed is
778
to send your patches to the FFmpeg mailing list.
779

    
780
@node Coding Rules
781
@section Coding Rules
782

    
783
FFmpeg is programmed in the ISO C90 language with a few additional
784
features from ISO C99, namely:
785
@itemize @bullet
786
@item
787
the @samp{inline} keyword;
788
@item
789
@samp{//} comments;
790
@item
791
designated struct initializers (@samp{struct s x = @{ .i = 17 @};})
792
@item
793
compound literals (@samp{x = (struct s) @{ 17, 23 @};})
794
@end itemize
795

    
796
These features are supported by all compilers we care about, so we will not
797
accept patches to remove their use unless they absolutely do not impair
798
clarity and performance.
799

    
800
All code must compile with GCC 2.95 and GCC 3.3. Currently, FFmpeg also
801
compiles with several other compilers, such as the Compaq ccc compiler
802
or Sun Studio 9, and we would like to keep it that way unless it would
803
be exceedingly involved. To ensure compatibility, please do not use any
804
additional C99 features or GCC extensions. Especially watch out for:
805
@itemize @bullet
806
@item
807
mixing statements and declarations;
808
@item
809
@samp{long long} (use @samp{int64_t} instead);
810
@item
811
@samp{__attribute__} not protected by @samp{#ifdef __GNUC__} or similar;
812
@item
813
GCC statement expressions (@samp{(x = (@{ int y = 4; y; @})}).
814
@end itemize
815

    
816
Indent size is 4.
817
The presentation is the one specified by 'indent -i4 -kr -nut'.
818
The TAB character is forbidden outside of Makefiles as is any
819
form of trailing whitespace. Commits containing either will be
820
rejected by the Subversion repository.
821

    
822
The main priority in FFmpeg is simplicity and small code size in order to
823
minimize the bug count.
824

    
825
Comments: Use the JavaDoc/Doxygen
826
format (see examples below) so that code documentation
827
can be generated automatically. All nontrivial functions should have a comment
828
above them explaining what the function does, even if it is just one sentence.
829
All structures and their member variables should be documented, too.
830
@example
831
/**
832
 * @@file mpeg.c
833
 * MPEG codec.
834
 * @@author ...
835
 */
836

    
837
/**
838
 * Summary sentence.
839
 * more text ...
840
 * ...
841
 */
842
typedef struct Foobar@{
843
    int var1; /**< var1 description */
844
    int var2; ///< var2 description
845
    /** var3 description */
846
    int var3;
847
@} Foobar;
848

    
849
/**
850
 * Summary sentence.
851
 * more text ...
852
 * ...
853
 * @@param my_parameter description of my_parameter
854
 * @@return return value description
855
 */
856
int myfunc(int my_parameter)
857
...
858
@end example
859

    
860
fprintf and printf are forbidden in libavformat and libavcodec,
861
please use av_log() instead.
862

    
863
Casts should be used only when necessary. Unneeded parentheses
864
should also be avoided if they don't make the code easier to understand.
865

    
866
@section Development Policy
867

    
868
@enumerate
869
@item
870
   Contributions should be licensed under the LGPL 2.1, including an
871
   "or any later version" clause, or the MIT license.  GPL 2 including
872
   an "or any later version" clause is also acceptable, but LGPL is
873
   preferred.
874
@item
875
   You must not commit code which breaks FFmpeg! (Meaning unfinished but
876
   enabled code which breaks compilation or compiles but does not work or
877
   breaks the regression tests)
878
   You can commit unfinished stuff (for testing etc), but it must be disabled
879
   (#ifdef etc) by default so it does not interfere with other developers'
880
   work.
881
@item
882
   You do not have to over-test things. If it works for you, and you think it
883
   should work for others, then commit. If your code has problems
884
   (portability, triggers compiler bugs, unusual environment etc) they will be
885
   reported and eventually fixed.
886
@item
887
   Do not commit unrelated changes together, split them into self-contained
888
   pieces. Also do not forget that if part B depends on part A, but A does not
889
   depend on B, then A can and should be committed first and separate from B.
890
   Keeping changes well split into self-contained parts makes reviewing and
891
   understanding them on the commit log mailing list easier. This also helps
892
   in case of debugging later on.
893
   Also if you have doubts about splitting or not splitting, do not hesitate to
894
   ask/discuss it on the developer mailing list.
895
@item
896
   Do not change behavior of the program (renaming options etc) without
897
   first discussing it on the ffmpeg-devel mailing list. Do not remove
898
   functionality from the code. Just improve!
899

    
900
   Note: Redundant code can be removed.
901
@item
902
   Do not commit changes to the build system (Makefiles, configure script)
903
   which change behavior, defaults etc, without asking first. The same
904
   applies to compiler warning fixes, trivial looking fixes and to code
905
   maintained by other developers. We usually have a reason for doing things
906
   the way we do. Send your changes as patches to the ffmpeg-devel mailing
907
   list, and if the code maintainers say OK, you may commit. This does not
908
   apply to files you wrote and/or maintain.
909
@item
910
   We refuse source indentation and other cosmetic changes if they are mixed
911
   with functional changes, such commits will be rejected and removed. Every
912
   developer has his own indentation style, you should not change it. Of course
913
   if you (re)write something, you can use your own style, even though we would
914
   prefer if the indentation throughout FFmpeg was consistent (Many projects
915
   force a given indentation style - we do not.). If you really need to make
916
   indentation changes (try to avoid this), separate them strictly from real
917
   changes.
918

    
919
   NOTE: If you had to put if()@{ .. @} over a large (> 5 lines) chunk of code,
920
   then either do NOT change the indentation of the inner part within (do not
921
   move it to the right)! or do so in a separate commit
922
@item
923
   Always fill out the commit log message. Describe in a few lines what you
924
   changed and why. You can refer to mailing list postings if you fix a
925
   particular bug. Comments such as "fixed!" or "Changed it." are unacceptable.
926
@item
927
   If you apply a patch by someone else, include the name and email address in
928
   the log message. Since the ffmpeg-cvslog mailing list is publicly
929
   archived you should add some SPAM protection to the email address. Send an
930
   answer to ffmpeg-devel (or wherever you got the patch from) saying that
931
   you applied the patch.
932
@item
933
   When applying patches that have been discussed (at length) on the mailing
934
   list, reference the thread in the log message.
935
@item
936
    Do NOT commit to code actively maintained by others without permission.
937
    Send a patch to ffmpeg-devel instead. If no one answers within a reasonable
938
    timeframe (12h for build failures and security fixes, 3 days small changes,
939
    1 week for big patches) then commit your patch if you think it is OK.
940
    Also note, the maintainer can simply ask for more time to review!
941
@item
942
    Subscribe to the ffmpeg-cvslog mailing list. The diffs of all commits
943
    are sent there and reviewed by all the other developers. Bugs and possible
944
    improvements or general questions regarding commits are discussed there. We
945
    expect you to react if problems with your code are uncovered.
946
@item
947
    Update the documentation if you change behavior or add features. If you are
948
    unsure how best to do this, send a patch to ffmpeg-devel, the documentation
949
    maintainer(s) will review and commit your stuff.
950
@item
951
    Try to keep important discussions and requests (also) on the public
952
    developer mailing list, so that all developers can benefit from them.
953
@item
954
    Never write to unallocated memory, never write over the end of arrays,
955
    always check values read from some untrusted source before using them
956
    as array index or other risky things.
957
@item
958
    Remember to check if you need to bump versions for the specific libav
959
    parts (libavutil, libavcodec, libavformat) you are changing. You need
960
    to change the version integer.
961
    Incrementing the first component means no backward compatibility to
962
    previous versions (e.g. removal of a function from the public API).
963
    Incrementing the second component means backward compatible change
964
    (e.g. addition of a function to the public API or extension of an
965
    existing data structure).
966
    Incrementing the third component means a noteworthy binary compatible
967
    change (e.g. encoder bug fix that matters for the decoder).
968
@item
969
    Compiler warnings indicate potential bugs or code with bad style. If a type of
970
    warning always points to correct and clean code, that warning should
971
    be disabled, not the code changed.
972
    Thus the remaining warnings can either be bugs or correct code.
973
    If it is a bug, the bug has to be fixed. If it is not, the code should
974
    be changed to not generate a warning unless that causes a slowdown
975
    or obfuscates the code.
976
@item
977
    If you add a new file, give it a proper license header. Do not copy and
978
    paste it from a random place, use an existing file as template.
979
@end enumerate
980

    
981
We think our rules are not too hard. If you have comments, contact us.
982

    
983
Note, these rules are mostly borrowed from the MPlayer project.
984

    
985
@section Submitting patches
986

    
987
First, (@pxref{Coding Rules}) above if you did not yet.
988

    
989
When you submit your patch, try to send a unified diff (diff '-up'
990
option). We cannot read other diffs :-)
991

    
992
Also please do not submit a patch which contains several unrelated changes.
993
Split it into separate, self-contained pieces. This does not mean splitting
994
file by file. Instead, make the patch as small as possible while still
995
keeping it as a logical unit that contains an individual change, even
996
if it spans multiple files. This makes reviewing your patches much easier
997
for us and greatly increases your chances of getting your patch applied.
998

    
999
Run the regression tests before submitting a patch so that you can
1000
verify that there are no big problems.
1001

    
1002
Patches should be posted as base64 encoded attachments (or any other
1003
encoding which ensures that the patch will not be trashed during
1004
transmission) to the ffmpeg-devel mailing list, see
1005
@url{http://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel}
1006

    
1007
It also helps quite a bit if you tell us what the patch does (for example
1008
'replaces lrint by lrintf'), and why (for example '*BSD isn't C99 compliant
1009
and has no lrint()')
1010

    
1011
Also please if you send several patches, send each patch as a separate mail,
1012
do not attach several unrelated patches to the same mail.
1013

    
1014
@section New codecs or formats checklist
1015

    
1016
@enumerate
1017
@item
1018
    Did you use av_cold for codec initialization and close functions?
1019
@item
1020
    Did you add a long_name under NULL_IF_CONFIG_SMALL to the AVCodec or
1021
    AVInputFormat/AVOutputFormat struct?
1022
@item
1023
    Did you bump the minor version number in @file{avcodec.h} or
1024
    @file{avformat.h}?
1025
@item
1026
    Did you register it in @file{allcodecs.c} or @file{allformats.c}?
1027
@item
1028
    Did you add the CodecID to @file{avcodec.h}?
1029
@item
1030
    If it has a fourcc, did you add it to @file{libavformat/riff.c},
1031
    even if it is only a decoder?
1032
@item
1033
    Did you add a rule to compile the appropriate files in the Makefile?
1034
    Remember to do this even if you're just adding a format to a file that is
1035
    already being compiled by some other rule, like a raw demuxer.
1036
@item
1037
    Did you add an entry to the table of supported formats or codecs in the
1038
    documentation?
1039
@item
1040
    Did you add an entry in the Changelog?
1041
@item
1042
    If it depends on a parser or a library, did you add that dependency in
1043
    configure?
1044
@item
1045
    Did you "svn add" the appropriate files before commiting?
1046
@end enumerate
1047

    
1048
@section patch submission checklist
1049

    
1050
@enumerate
1051
@item
1052
    Do the regression tests pass with the patch applied?
1053
@item
1054
    Does @code{make checkheaders} pass with the patch applied?
1055
@item
1056
    Is the patch a unified diff?
1057
@item
1058
    Is the patch against latest FFmpeg SVN?
1059
@item
1060
    Are you subscribed to ffmpeg-dev?
1061
    (the list is subscribers only due to spam)
1062
@item
1063
    Have you checked that the changes are minimal, so that the same cannot be
1064
    achieved with a smaller patch and/or simpler final code?
1065
@item
1066
    If the change is to speed critical code, did you benchmark it?
1067
@item
1068
    If you did any benchmarks, did you provide them in the mail?
1069
@item
1070
    Have you checked that the patch does not introduce buffer overflows or
1071
    other security issues?
1072
@item
1073
    Did you test your decoder or demuxer against damaged data? If no, see
1074
    tools/trasher and the noise bitstream filter. Your decoder or demuxer
1075
    should not crash or end in a (near) infinite loop when fed damaged data.
1076
@item
1077
    Is the patch created from the root of the source tree, so it can be
1078
    applied with @code{patch -p0}?
1079
@item
1080
    Does the patch not mix functional and cosmetic changes?
1081
@item
1082
    Did you add tabs or trailing whitespace to the code? Both are forbidden.
1083
@item
1084
    Is the patch attached to the email you send?
1085
@item
1086
    Is the mime type of the patch correct? It should be text/x-diff or
1087
    text/x-patch or at least text/plain and not application/octet-stream.
1088
@item
1089
    If the patch fixes a bug, did you provide a verbose analysis of the bug?
1090
@item
1091
    If the patch fixes a bug, did you provide enough information, including
1092
    a sample, so the bug can be reproduced and the fix can be verified?
1093
    Note please do not attach samples >100k to mails but rather provide a
1094
    URL, you can upload to ftp://upload.ffmpeg.org
1095
@item
1096
    Did you provide a verbose summary about what the patch does change?
1097
@item
1098
    Did you provide a verbose explanation why it changes things like it does?
1099
@item
1100
    Did you provide a verbose summary of the user visible advantages and
1101
    disadvantages if the patch is applied?
1102
@item
1103
    Did you provide an example so we can verify the new feature added by the
1104
    patch easily?
1105
@item
1106
    If you added a new file, did you insert a license header? It should be
1107
    taken from FFmpeg, not randomly copied and pasted from somewhere else.
1108
@item
1109
    You should maintain alphabetical order in alphabetically ordered lists as
1110
    long as doing so does not break API/ABI compatibility.
1111
@item
1112
    Lines with similar content should be aligned vertically when doing so
1113
    improves readability.
1114
@item
1115
    Did you provide a suggestion for a clear commit log message?
1116
@end enumerate
1117

    
1118
@section Patch review process
1119

    
1120
All patches posted to ffmpeg-devel will be reviewed, unless they contain a
1121
clear note that the patch is not for SVN.
1122
Reviews and comments will be posted as replies to the patch on the
1123
mailing list. The patch submitter then has to take care of every comment,
1124
that can be by resubmitting a changed patch or by discussion. Resubmitted
1125
patches will themselves be reviewed like any other patch. If at some point
1126
a patch passes review with no comments then it is approved, that can for
1127
simple and small patches happen immediately while large patches will generally
1128
have to be changed and reviewed many times before they are approved.
1129
After a patch is approved it will be committed to the repository.
1130

    
1131
We will review all submitted patches, but sometimes we are quite busy so
1132
especially for large patches this can take several weeks.
1133

    
1134
When resubmitting patches, please do not make any significant changes
1135
not related to the comments received during review. Such patches will
1136
be rejected. Instead, submit  significant changes or new features as
1137
separate patches.
1138

    
1139
@section Regression tests
1140

    
1141
Before submitting a patch (or committing to the repository), you should at least
1142
test that you did not break anything.
1143

    
1144
The regression tests build a synthetic video stream and a synthetic
1145
audio stream. These are then encoded and decoded with all codecs or
1146
formats. The CRC (or MD5) of each generated file is recorded in a
1147
result file. A 'diff' is launched to compare the reference results and
1148
the result file.
1149

    
1150
The regression tests then go on to test the FFserver code with a
1151
limited set of streams. It is important that this step runs correctly
1152
as well.
1153

    
1154
Run 'make test' to test all the codecs and formats.
1155

    
1156
Run 'make fulltest' to test all the codecs, formats and FFserver.
1157

    
1158
[Of course, some patches may change the results of the regression tests. In
1159
this case, the reference results of the regression tests shall be modified
1160
accordingly].
1161

    
1162
@bye