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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 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 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
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the latest versions of MSYS and MinGW from @url{http://www.mingw.org/}.
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You can find detailed installation
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instructions in the download section and the FAQ.
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476
FFmpeg does not build out-of-the-box with the packages the automated MinGW
477
installer provides. It also requires coreutils to be installed and many other
478
packages updated to the latest version. The minimum version for some packages
479
are listed below:
480

    
481
@itemize
482
@item bash 3.1
483
@item msys-make 3.81-2 (note: not mingw32-make)
484
@item w32api 3.13
485
@item mingw-runtime 3.15
486
@end itemize
487

    
488
You will also need to pass @code{-fno-common} to the compiler to work around
489
a GCC bug (see @url{http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37216}).
490

    
491
Within the MSYS shell, configure and make with:
492

    
493
@example
494
./configure --enable-memalign-hack --extra-cflags=-fno-common
495
make
496
make install
497
@end example
498

    
499
This will install @file{ffmpeg.exe} along with many other development files
500
to @file{/usr/local}. You may specify another install path using the
501
@code{--prefix} option in @file{configure}.
502

    
503
Notes:
504

    
505
@itemize
506

    
507
@item In order to compile vhooks, you must have a POSIX-compliant libdl in
508
your MinGW system. Get dlfcn-win32 from
509
@url{http://code.google.com/p/dlfcn-win32}.
510

    
511
@item In order to compile FFplay, you must have the MinGW development library
512
of SDL. Get it from @url{http://www.libsdl.org}.
513
Edit the @file{bin/sdl-config} script so that it points to the correct prefix
514
where SDL was installed. Verify that @file{sdl-config} can be launched from
515
the MSYS command line.
516

    
517
@item By using @code{./configure --enable-shared} when configuring FFmpeg,
518
you can build libavutil, libavcodec and libavformat as DLLs.
519

    
520
@end itemize
521

    
522
@subsection Microsoft Visual C++ compatibility
523

    
524
As stated in the FAQ, FFmpeg will not compile under MSVC++. However, if you
525
want to use the libav* libraries in your own applications, you can still
526
compile those applications using MSVC++. But the libav* libraries you link
527
to @emph{must} be built with MinGW. However, you will not be able to debug
528
inside the libav* libraries, since MSVC++ does not recognize the debug
529
symbols generated by GCC.
530
We strongly recommend you to move over from MSVC++ to MinGW tools.
531

    
532
This description of how to use the FFmpeg libraries with MSVC++ is based on
533
Microsoft Visual C++ 2005 Express Edition. If you have a different version,
534
you might have to modify the procedures slightly.
535

    
536
@subsubsection Using static libraries
537

    
538
Assuming you have just built and installed FFmpeg in @file{/usr/local}.
539

    
540
@enumerate
541

    
542
@item Create a new console application ("File / New / Project") and then
543
select "Win32 Console Application". On the appropriate page of the
544
Application Wizard, uncheck the "Precompiled headers" option.
545

    
546
@item Write the source code for your application, or, for testing, just
547
copy the code from an existing sample application into the source file
548
that MSVC++ has already created for you. For example, you can copy
549
@file{output_example.c} from the FFmpeg distribution.
550

    
551
@item Open the "Project / Properties" dialog box. In the "Configuration"
552
combo box, select "All Configurations" so that the changes you make will
553
affect both debug and release builds. In the tree view on the left hand
554
side, select "C/C++ / General", then edit the "Additional Include
555
Directories" setting to contain the path where the FFmpeg includes were
556
installed (i.e. @file{c:\msys\1.0\local\include}).
557
Do not add MinGW's include directory here, or the include files will
558
conflict with MSVC's.
559

    
560
@item Still in the "Project / Properties" dialog box, select
561
"Linker / General" from the tree view and edit the
562
"Additional Library Directories" setting to contain the @file{lib}
563
directory where FFmpeg was installed (i.e. @file{c:\msys\1.0\local\lib}),
564
the directory where MinGW libs are installed (i.e. @file{c:\mingw\lib}),
565
and the directory where MinGW's GCC libs are installed
566
(i.e. @file{C:\mingw\lib\gcc\mingw32\4.2.1-sjlj}). Then select
567
"Linker / Input" from the tree view, and add the files @file{libavformat.a},
568
@file{libavcodec.a}, @file{libavutil.a}, @file{libmingwex.a},
569
@file{libgcc.a}, and any other libraries you used (i.e. @file{libz.a})
570
to the end of "Additional Dependencies".
571

    
572
@item Now, select "C/C++ / Code Generation" from the tree view. Select
573
"Debug" in the "Configuration" combo box. Make sure that "Runtime
574
Library" is set to "Multi-threaded Debug DLL". Then, select "Release" in
575
the "Configuration" combo box and make sure that "Runtime Library" is
576
set to "Multi-threaded DLL".
577

    
578
@item Click "OK" to close the "Project / Properties" dialog box.
579

    
580
@item MSVC++ lacks some C99 header files that are fundamental for FFmpeg.
581
Get msinttypes from @url{http://code.google.com/p/msinttypes/downloads/list}
582
and install it in MSVC++'s include directory
583
(i.e. @file{C:\Program Files\Microsoft Visual Studio 8\VC\include}).
584

    
585
@item MSVC++ also does not understand the @code{inline} keyword used by
586
FFmpeg, so you must add this line before @code{#include}ing libav*:
587
@example
588
#define inline _inline
589
@end example
590

    
591
@item Build your application, everything should work.
592

    
593
@end enumerate
594

    
595
@subsubsection Using shared libraries
596

    
597
This is how to create DLL and LIB files that are compatible with MSVC++:
598

    
599
@enumerate
600

    
601
@item Add a call to @file{vcvars32.bat} (which sets up the environment
602
variables for the Visual C++ tools) as the first line of @file{msys.bat}.
603
The standard location for @file{vcvars32.bat} is
604
@file{C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat},
605
and the standard location for @file{msys.bat} is @file{C:\msys\1.0\msys.bat}.
606
If this corresponds to your setup, add the following line as the first line
607
of @file{msys.bat}:
608

    
609
@example
610
call "C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat"
611
@end example
612

    
613
Alternatively, you may start the @file{Visual Studio 2005 Command Prompt},
614
and run @file{c:\msys\1.0\msys.bat} from there.
615

    
616
@item Within the MSYS shell, run @code{lib.exe}. If you get a help message
617
from @file{Microsoft (R) Library Manager}, this means your environment
618
variables are set up correctly, the @file{Microsoft (R) Library Manager}
619
is on the path and will be used by FFmpeg to create
620
MSVC++-compatible import libraries.
621

    
622
@item Build FFmpeg with
623

    
624
@example
625
./configure --enable-shared --enable-memalign-hack
626
make
627
make install
628
@end example
629

    
630
Your install path (@file{/usr/local/} by default) should now have the
631
necessary DLL and LIB files under the @file{bin} directory.
632

    
633
@end enumerate
634

    
635
To use those files with MSVC++, do the same as you would do with
636
the static libraries, as described above. But in Step 4,
637
you should only need to add the directory where the LIB files are installed
638
(i.e. @file{c:\msys\usr\local\bin}). This is not a typo, the LIB files are
639
installed in the @file{bin} directory. And instead of adding @file{libxx.a}
640
files, you should add @file{avcodec.lib}, @file{avformat.lib}, and
641
@file{avutil.lib}. There should be no need for @file{libmingwex.a},
642
@file{libgcc.a}, and @file{wsock32.lib}, nor any other external library
643
statically linked into the DLLs. The @file{bin} directory contains a bunch
644
of DLL files, but the ones that are actually used to run your application
645
are the ones with a major version number in their filenames
646
(i.e. @file{avcodec-51.dll}).
647

    
648
@subsection Cross compilation for Windows with Linux
649

    
650
You must use the MinGW cross compilation tools available at
651
@url{http://www.mingw.org/}.
652

    
653
Then configure FFmpeg with the following options:
654
@example
655
./configure --target-os=mingw32 --cross-prefix=i386-mingw32msvc-
656
@end example
657
(you can change the cross-prefix according to the prefix chosen for the
658
MinGW tools).
659

    
660
Then you can easily test FFmpeg with Wine
661
(@url{http://www.winehq.com/}).
662

    
663
@subsection Compilation under Cygwin
664

    
665
The main issue with Cygwin is that newlib, its C library, does not
666
contain llrint().  However, it is possible to leverage the
667
implementation in MinGW.
668

    
669
Just install your Cygwin with all the "Base" packages, plus the
670
following "Devel" ones:
671
@example
672
binutils, gcc-core, make, subversion, mingw-runtime
673
@end example
674

    
675
Do not install binutils-20060709-1 (they are buggy on shared builds);
676
use binutils-20050610-1 instead.
677

    
678
Then create a small library that just contains llrint():
679

    
680
@example
681
ar x /usr/lib/mingw/libmingwex.a llrint.o
682
ar cq /usr/local/lib/libllrint.a llrint.o
683
@end example
684

    
685
Then run
686

    
687
@example
688
./configure --enable-static --disable-shared  --extra-ldflags='-L /usr/local/lib' --extra-libs='-l llrint'
689
@end example
690

    
691
to make a static build or
692

    
693
@example
694
./configure --enable-shared --disable-static  --extra-ldflags='-L /usr/local/lib' --extra-libs='-l llrint'
695
@end example
696

    
697
to build shared libraries.
698

    
699
If you want to build FFmpeg with additional libraries, download Cygwin
700
"Devel" packages for Ogg and Vorbis from any Cygwin packages repository
701
and/or SDL, xvid, faac, faad2 packages from Cygwin Ports,
702
(@url{http://cygwinports.dotsrc.org/}).
703

    
704
@subsection Crosscompilation for Windows under Cygwin
705

    
706
With Cygwin you can create Windows binaries that do not need the cygwin1.dll.
707

    
708
Just install your Cygwin as explained before, plus these additional
709
"Devel" packages:
710
@example
711
gcc-mingw-core, mingw-runtime, mingw-zlib
712
@end example
713

    
714
and add some special flags to your configure invocation.
715

    
716
For a static build run
717
@example
718
./configure --target-os=mingw32 --enable-memalign-hack --enable-static --disable-shared --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
719
@end example
720

    
721
and for a build with shared libraries
722
@example
723
./configure --target-os=mingw32 --enable-memalign-hack --enable-shared --disable-static --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
724
@end example
725

    
726
@section BeOS
727

    
728
BeOS support is broken in mysterious ways.
729

    
730
@section OS/2
731

    
732
For information about compiling FFmpeg on OS/2 see
733
@url{http://www.edm2.com/index.php/FFmpeg}.
734

    
735
@chapter Developers Guide
736

    
737
@section API
738
@itemize @bullet
739
@item libavcodec is the library containing the codecs (both encoding and
740
decoding). Look at @file{libavcodec/apiexample.c} to see how to use it.
741

    
742
@item libavformat is the library containing the file format handling (mux and
743
demux code for several formats). Look at @file{ffplay.c} to use it in a
744
player. See @file{output_example.c} to use it to generate audio or video
745
streams.
746

    
747
@end itemize
748

    
749
@section Integrating libavcodec or libavformat in your program
750

    
751
You can integrate all the source code of the libraries to link them
752
statically to avoid any version problem. All you need is to provide a
753
'config.mak' and a 'config.h' in the parent directory. See the defines
754
generated by ./configure to understand what is needed.
755

    
756
You can use libavcodec or libavformat in your commercial program, but
757
@emph{any patch you make must be published}. The best way to proceed is
758
to send your patches to the FFmpeg mailing list.
759

    
760
@node Coding Rules
761
@section Coding Rules
762

    
763
FFmpeg is programmed in the ISO C90 language with a few additional
764
features from ISO C99, namely:
765
@itemize @bullet
766
@item
767
the @samp{inline} keyword;
768
@item
769
@samp{//} comments;
770
@item
771
designated struct initializers (@samp{struct s x = @{ .i = 17 @};})
772
@item
773
compound literals (@samp{x = (struct s) @{ 17, 23 @};})
774
@end itemize
775

    
776
These features are supported by all compilers we care about, so we will not
777
accept patches to remove their use unless they absolutely do not impair
778
clarity and performance.
779

    
780
All code must compile with GCC 2.95 and GCC 3.3. Currently, FFmpeg also
781
compiles with several other compilers, such as the Compaq ccc compiler
782
or Sun Studio 9, and we would like to keep it that way unless it would
783
be exceedingly involved. To ensure compatibility, please do not use any
784
additional C99 features or GCC extensions. Especially watch out for:
785
@itemize @bullet
786
@item
787
mixing statements and declarations;
788
@item
789
@samp{long long} (use @samp{int64_t} instead);
790
@item
791
@samp{__attribute__} not protected by @samp{#ifdef __GNUC__} or similar;
792
@item
793
GCC statement expressions (@samp{(x = (@{ int y = 4; y; @})}).
794
@end itemize
795

    
796
Indent size is 4.
797
The presentation is the one specified by 'indent -i4 -kr -nut'.
798
The TAB character is forbidden outside of Makefiles as is any
799
form of trailing whitespace. Commits containing either will be
800
rejected by the Subversion repository.
801

    
802
The main priority in FFmpeg is simplicity and small code size in order to
803
minimize the bug count.
804

    
805
Comments: Use the JavaDoc/Doxygen
806
format (see examples below) so that code documentation
807
can be generated automatically. All nontrivial functions should have a comment
808
above them explaining what the function does, even if it is just one sentence.
809
All structures and their member variables should be documented, too.
810
@example
811
/**
812
 * @@file mpeg.c
813
 * MPEG codec.
814
 * @@author ...
815
 */
816

    
817
/**
818
 * Summary sentence.
819
 * more text ...
820
 * ...
821
 */
822
typedef struct Foobar@{
823
    int var1; /**< var1 description */
824
    int var2; ///< var2 description
825
    /** var3 description */
826
    int var3;
827
@} Foobar;
828

    
829
/**
830
 * Summary sentence.
831
 * more text ...
832
 * ...
833
 * @@param my_parameter description of my_parameter
834
 * @@return return value description
835
 */
836
int myfunc(int my_parameter)
837
...
838
@end example
839

    
840
fprintf and printf are forbidden in libavformat and libavcodec,
841
please use av_log() instead.
842

    
843
Casts should be used only when necessary. Unneeded parentheses
844
should also be avoided if they don't make the code easier to understand.
845

    
846
@section Development Policy
847

    
848
@enumerate
849
@item
850
   Contributions should be licensed under the LGPL 2.1, including an
851
   "or any later version" clause, or the MIT license.  GPL 2 including
852
   an "or any later version" clause is also acceptable, but LGPL is
853
   preferred.
854
@item
855
   You must not commit code which breaks FFmpeg! (Meaning unfinished but
856
   enabled code which breaks compilation or compiles but does not work or
857
   breaks the regression tests)
858
   You can commit unfinished stuff (for testing etc), but it must be disabled
859
   (#ifdef etc) by default so it does not interfere with other developers'
860
   work.
861
@item
862
   You do not have to over-test things. If it works for you, and you think it
863
   should work for others, then commit. If your code has problems
864
   (portability, triggers compiler bugs, unusual environment etc) they will be
865
   reported and eventually fixed.
866
@item
867
   Do not commit unrelated changes together, split them into self-contained
868
   pieces. Also do not forget that if part B depends on part A, but A does not
869
   depend on B, then A can and should be committed first and separate from B.
870
   Keeping changes well split into self-contained parts makes reviewing and
871
   understanding them on the commit log mailing list easier. This also helps
872
   in case of debugging later on.
873
   Also if you have doubts about splitting or not splitting, do not hesitate to
874
   ask/discuss it on the developer mailing list.
875
@item
876
   Do not change behavior of the program (renaming options etc) without
877
   first discussing it on the ffmpeg-devel mailing list. Do not remove
878
   functionality from the code. Just improve!
879

    
880
   Note: Redundant code can be removed.
881
@item
882
   Do not commit changes to the build system (Makefiles, configure script)
883
   which change behavior, defaults etc, without asking first. The same
884
   applies to compiler warning fixes, trivial looking fixes and to code
885
   maintained by other developers. We usually have a reason for doing things
886
   the way we do. Send your changes as patches to the ffmpeg-devel mailing
887
   list, and if the code maintainers say OK, you may commit. This does not
888
   apply to files you wrote and/or maintain.
889
@item
890
   We refuse source indentation and other cosmetic changes if they are mixed
891
   with functional changes, such commits will be rejected and removed. Every
892
   developer has his own indentation style, you should not change it. Of course
893
   if you (re)write something, you can use your own style, even though we would
894
   prefer if the indentation throughout FFmpeg was consistent (Many projects
895
   force a given indentation style - we do not.). If you really need to make
896
   indentation changes (try to avoid this), separate them strictly from real
897
   changes.
898

    
899
   NOTE: If you had to put if()@{ .. @} over a large (> 5 lines) chunk of code,
900
   then either do NOT change the indentation of the inner part within (do not
901
   move it to the right)! or do so in a separate commit
902
@item
903
   Always fill out the commit log message. Describe in a few lines what you
904
   changed and why. You can refer to mailing list postings if you fix a
905
   particular bug. Comments such as "fixed!" or "Changed it." are unacceptable.
906
@item
907
   If you apply a patch by someone else, include the name and email address in
908
   the log message. Since the ffmpeg-cvslog mailing list is publicly
909
   archived you should add some SPAM protection to the email address. Send an
910
   answer to ffmpeg-devel (or wherever you got the patch from) saying that
911
   you applied the patch.
912
@item
913
   When applying patches that have been discussed (at length) on the mailing
914
   list, reference the thread in the log message.
915
@item
916
    Do NOT commit to code actively maintained by others without permission.
917
    Send a patch to ffmpeg-devel instead. If no one answers within a reasonable
918
    timeframe (12h for build failures and security fixes, 3 days small changes,
919
    1 week for big patches) then commit your patch if you think it is OK.
920
    Also note, the maintainer can simply ask for more time to review!
921
@item
922
    Subscribe to the ffmpeg-cvslog mailing list. The diffs of all commits
923
    are sent there and reviewed by all the other developers. Bugs and possible
924
    improvements or general questions regarding commits are discussed there. We
925
    expect you to react if problems with your code are uncovered.
926
@item
927
    Update the documentation if you change behavior or add features. If you are
928
    unsure how best to do this, send a patch to ffmpeg-devel, the documentation
929
    maintainer(s) will review and commit your stuff.
930
@item
931
    Try to keep important discussions and requests (also) on the public
932
    developer mailing list, so that all developers can benefit from them.
933
@item
934
    Never write to unallocated memory, never write over the end of arrays,
935
    always check values read from some untrusted source before using them
936
    as array index or other risky things.
937
@item
938
    Remember to check if you need to bump versions for the specific libav
939
    parts (libavutil, libavcodec, libavformat) you are changing. You need
940
    to change the version integer.
941
    Incrementing the first component means no backward compatibility to
942
    previous versions (e.g. removal of a function from the public API).
943
    Incrementing the second component means backward compatible change
944
    (e.g. addition of a function to the public API or extension of an
945
    existing data structure).
946
    Incrementing the third component means a noteworthy binary compatible
947
    change (e.g. encoder bug fix that matters for the decoder).
948
@item
949
    Compiler warnings indicate potential bugs or code with bad style. If a type of
950
    warning always points to correct and clean code, that warning should
951
    be disabled, not the code changed.
952
    Thus the remaining warnings can either be bugs or correct code.
953
    If it is a bug, the bug has to be fixed. If it is not, the code should
954
    be changed to not generate a warning unless that causes a slowdown
955
    or obfuscates the code.
956
@item
957
    If you add a new file, give it a proper license header. Do not copy and
958
    paste it from a random place, use an existing file as template.
959
@end enumerate
960

    
961
We think our rules are not too hard. If you have comments, contact us.
962

    
963
Note, these rules are mostly borrowed from the MPlayer project.
964

    
965
@section Submitting patches
966

    
967
First, (@pxref{Coding Rules}) above if you did not yet.
968

    
969
When you submit your patch, try to send a unified diff (diff '-up'
970
option). We cannot read other diffs :-)
971

    
972
Also please do not submit a patch which contains several unrelated changes.
973
Split it into separate, self-contained pieces. This does not mean splitting
974
file by file. Instead, make the patch as small as possible while still
975
keeping it as a logical unit that contains an individual change, even
976
if it spans multiple files. This makes reviewing your patches much easier
977
for us and greatly increases your chances of getting your patch applied.
978

    
979
Run the regression tests before submitting a patch so that you can
980
verify that there are no big problems.
981

    
982
Patches should be posted as base64 encoded attachments (or any other
983
encoding which ensures that the patch will not be trashed during
984
transmission) to the ffmpeg-devel mailing list, see
985
@url{http://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel}
986

    
987
It also helps quite a bit if you tell us what the patch does (for example
988
'replaces lrint by lrintf'), and why (for example '*BSD isn't C99 compliant
989
and has no lrint()')
990

    
991
Also please if you send several patches, send each patch as a separate mail,
992
do not attach several unrelated patches to the same mail.
993

    
994
@section New codecs or formats checklist
995

    
996
@enumerate
997
@item
998
    Did you use av_cold for codec initialization and close functions?
999
@item
1000
    Did you add a long_name under NULL_IF_CONFIG_SMALL to the AVCodec or
1001
    AVInputFormat/AVOutputFormat struct?
1002
@item
1003
    Did you bump the minor version number in @file{avcodec.h} or
1004
    @file{avformat.h}?
1005
@item
1006
    Did you register it in @file{allcodecs.c} or @file{allformats.c}?
1007
@item
1008
    Did you add the CodecID to @file{avcodec.h}?
1009
@item
1010
    If it has a fourcc, did you add it to @file{libavformat/riff.c},
1011
    even if it is only a decoder?
1012
@item
1013
    Did you add a rule to compile the appropriate files in the Makefile?
1014
    Remember to do this even if you're just adding a format to a file that is
1015
    already being compiled by some other rule, like a raw demuxer.
1016
@item
1017
    Did you add an entry to the table of supported formats or codecs in the
1018
    documentation?
1019
@item
1020
    Did you add an entry in the Changelog?
1021
@item
1022
    If it depends on a parser or a library, did you add that dependency in
1023
    configure?
1024
@item
1025
    Did you "svn add" the appropriate files before commiting?
1026
@end enumerate
1027

    
1028
@section patch submission checklist
1029

    
1030
@enumerate
1031
@item
1032
    Do the regression tests pass with the patch applied?
1033
@item
1034
    Does @code{make checkheaders} pass with the patch applied?
1035
@item
1036
    Is the patch a unified diff?
1037
@item
1038
    Is the patch against latest FFmpeg SVN?
1039
@item
1040
    Are you subscribed to ffmpeg-dev?
1041
    (the list is subscribers only due to spam)
1042
@item
1043
    Have you checked that the changes are minimal, so that the same cannot be
1044
    achieved with a smaller patch and/or simpler final code?
1045
@item
1046
    If the change is to speed critical code, did you benchmark it?
1047
@item
1048
    If you did any benchmarks, did you provide them in the mail?
1049
@item
1050
    Have you checked that the patch does not introduce buffer overflows or
1051
    other security issues?
1052
@item
1053
    Did you test your decoder or demuxer against damaged data? If no, see
1054
    tools/trasher and the noise bitstream filter. Your decoder or demuxer
1055
    should not crash or end in a (near) infinite loop when fed damaged data.
1056
@item
1057
    Is the patch created from the root of the source tree, so it can be
1058
    applied with @code{patch -p0}?
1059
@item
1060
    Does the patch not mix functional and cosmetic changes?
1061
@item
1062
    Did you add tabs or trailing whitespace to the code? Both are forbidden.
1063
@item
1064
    Is the patch attached to the email you send?
1065
@item
1066
    Is the mime type of the patch correct? It should be text/x-diff or
1067
    text/x-patch or at least text/plain and not application/octet-stream.
1068
@item
1069
    If the patch fixes a bug, did you provide a verbose analysis of the bug?
1070
@item
1071
    If the patch fixes a bug, did you provide enough information, including
1072
    a sample, so the bug can be reproduced and the fix can be verified?
1073
    Note please do not attach samples >100k to mails but rather provide a
1074
    URL, you can upload to ftp://upload.mplayerhq.hu
1075
@item
1076
    Did you provide a verbose summary about what the patch does change?
1077
@item
1078
    Did you provide a verbose explanation why it changes things like it does?
1079
@item
1080
    Did you provide a verbose summary of the user visible advantages and
1081
    disadvantages if the patch is applied?
1082
@item
1083
    Did you provide an example so we can verify the new feature added by the
1084
    patch easily?
1085
@item
1086
    If you added a new file, did you insert a license header? It should be
1087
    taken from FFmpeg, not randomly copied and pasted from somewhere else.
1088
@item
1089
    You should maintain alphabetical order in alphabetically ordered lists as
1090
    long as doing so does not break API/ABI compatibility.
1091
@item
1092
    Lines with similar content should be aligned vertically when doing so
1093
    improves readability.
1094
@item
1095
    Did you provide a suggestion for a clear commit log message?
1096
@end enumerate
1097

    
1098
@section Patch review process
1099

    
1100
All patches posted to ffmpeg-devel will be reviewed, unless they contain a
1101
clear note that the patch is not for SVN.
1102
Reviews and comments will be posted as replies to the patch on the
1103
mailing list. The patch submitter then has to take care of every comment,
1104
that can be by resubmitting a changed patch or by discussion. Resubmitted
1105
patches will themselves be reviewed like any other patch. If at some point
1106
a patch passes review with no comments then it is approved, that can for
1107
simple and small patches happen immediately while large patches will generally
1108
have to be changed and reviewed many times before they are approved.
1109
After a patch is approved it will be committed to the repository.
1110

    
1111
We will review all submitted patches, but sometimes we are quite busy so
1112
especially for large patches this can take several weeks.
1113

    
1114
When resubmitting patches, please do not make any significant changes
1115
not related to the comments received during review. Such patches will
1116
be rejected. Instead, submit  significant changes or new features as
1117
separate patches.
1118

    
1119
@section Regression tests
1120

    
1121
Before submitting a patch (or committing to the repository), you should at least
1122
test that you did not break anything.
1123

    
1124
The regression tests build a synthetic video stream and a synthetic
1125
audio stream. These are then encoded and decoded with all codecs or
1126
formats. The CRC (or MD5) of each generated file is recorded in a
1127
result file. A 'diff' is launched to compare the reference results and
1128
the result file.
1129

    
1130
The regression tests then go on to test the FFserver code with a
1131
limited set of streams. It is important that this step runs correctly
1132
as well.
1133

    
1134
Run 'make test' to test all the codecs and formats.
1135

    
1136
Run 'make fulltest' to test all the codecs, formats and FFserver.
1137

    
1138
[Of course, some patches may change the results of the regression tests. In
1139
this case, the reference results of the regression tests shall be modified
1140
accordingly].
1141

    
1142
@bye