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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 Audio IFF (AIFF)          @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 3GPP AMR                  @tab X @tab X
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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 AVISynth                  @tab   @tab X
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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 Beam Software 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 Bethesda Softworks VID    @tab   @tab X
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    @tab Used in some games from Bethesda Softworks.
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@item Brute Force & Ignorance   @tab   @tab X
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    @tab Used in the game Flash Traffic: City of Angels.
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@item Interplay C93             @tab   @tab X
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    @tab Used in the game Cyberia from Interplay.
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@item Delphine Software International CIN @tab   @tab X
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    @tab Multimedia format used by Delphine Software games.
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@item CRC testing format        @tab X @tab
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@item Creative Voice            @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 D-Cinema audio            @tab X @tab X
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@item DV video                  @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 cdata  @tab    @tab X
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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 FFM (FFserver live feed)  @tab X @tab X
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@item Flash (SWF)               @tab X @tab X
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@item Flash 9 (AVM2)            @tab X @tab X
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    @tab Only embedded audio is decoded.
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@item FLI/FLC/FLX animation     @tab   @tab X
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    @tab .fli/.flc files
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@item Flash Video (FLV)         @tab   @tab X
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    @tab Macromedia Flash video files
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@item framecrc testing format   @tab X @tab
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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 GIF Animation             @tab X @tab
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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 Quake II CIN video     @tab   @tab X
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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 Matroska audio            @tab X @tab
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@item MAXIS 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/MP4         @tab X @tab X
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    @tab 3GP, 3GP2, PSP, iPod variants supported
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@item MP2                       @tab X @tab X
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@item MP3                       @tab X @tab X
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@item MPEG-1 System             @tab X @tab X
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    @tab muxed audio and video, VCD format supported
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@item MPEG-PS (program stream)  @tab X @tab X
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    @tab also known as @code{VOB} file, SVCD and DVD format supported
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@item MPEG-TS (transport stream) @tab X @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 MIME multipart JPEG       @tab X @tab
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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 MTV                       @tab   @tab X
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@item Musepack                  @tab   @tab X
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@item Musepack SV8              @tab   @tab X
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@item Material eXchange Format (MXF) @tab X @tab X
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    @tab SMPTE 377M, used by D-Cinema, broadcast industry.
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@item Material eXchange Format (MXF), D-10 Mapping @tab X @tab X
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    @tab SMPTE 386M, D-10/IMX Mapping.
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@item NC camera feed            @tab   @tab X
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    @tab NC (AVIP NC4600) camera streams
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@item NTT TwinVQ (VQF)          @tab   @tab X
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    @tab Nippon Telegraph and Telephone Corporation TwinVQ.
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@item Nullsoft Streaming Video  @tab   @tab X
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@item NuppelVideo               @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 Ogg                       @tab X @tab X
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@item TechnoTrend PVA           @tab   @tab X
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    @tab Used by TechnoTrend DVB PCI boards.
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@item raw ADTS (AAC)            @tab X @tab X
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@item raw AC-3                  @tab X @tab X
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@item raw Chinese AVS video     @tab   @tab X
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@item raw CRI ADX               @tab X @tab X
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@item raw Dirac                 @tab X @tab X
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@item raw DNxHD                 @tab X @tab X
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@item raw DTS                   @tab X @tab X
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@item raw E-AC-3                @tab X @tab X
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@item raw FLAC                  @tab X @tab X
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@item raw GSM                   @tab   @tab X
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@item raw H.261                 @tab X @tab X
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@item raw H.263                 @tab X @tab X
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@item raw H.264                 @tab X @tab X
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@item raw Ingenient MJPEG       @tab   @tab X
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@item raw MJPEG                 @tab X @tab X
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@item raw MLP                   @tab   @tab X
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@item raw MPEG                  @tab   @tab X
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@item raw MPEG-1                @tab   @tab X
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@item raw MPEG-2                @tab   @tab X
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@item raw MPEG-4                @tab X @tab X
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@item raw NULL                  @tab X @tab
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@item raw video                 @tab X @tab X
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@item raw id RoQ                @tab X @tab
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@item raw Shorten               @tab   @tab X
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@item raw VC-1                  @tab   @tab X
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@item raw PCM A-law             @tab X @tab X
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@item raw PCM mu-law            @tab X @tab X
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@item raw PCM signed 8 bit      @tab X @tab X
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@item raw PCM signed 16 bit big-endian  @tab X @tab X
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@item raw PCM signed 16 bit little-endian  @tab X @tab X
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@item raw PCM signed 24 bit big-endian  @tab X @tab X
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@item raw PCM signed 24 bit little-endian  @tab X @tab X
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@item raw PCM signed 32 bit big-endian  @tab X @tab X
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@item raw PCM signed 32 bit little-endian  @tab X @tab X
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@item raw PCM unsigned 8 bit    @tab X @tab X
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@item raw PCM unsigned 16 bit big-endian  @tab X @tab X
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@item raw PCM unsigned 16 bit little-endian  @tab X @tab X
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@item raw PCM unsigned 24 bit big-endian  @tab X @tab X
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@item raw PCM unsigned 24 bit little-endian  @tab X @tab X
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@item raw PCM unsigned 32 bit big-endian  @tab X @tab X
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@item raw PCM unsigned 32 bit little-endian  @tab X @tab X
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@item raw PCM floating-point 32 bit big-endian  @tab X @tab X
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@item raw PCM floating-point 32 bit little-endian  @tab X @tab X
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@item raw PCM floating-point 64 bit big-endian  @tab X @tab X
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@item raw PCM floating-point 64 bit little-endian  @tab X @tab X
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@item RDT                       @tab   @tab X
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@item REDCODE R3D               @tab   @tab X
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    @tab File format used by RED Digital cameras, contains JPEG 2000 frames and PCM audio.
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@item RealMedia                 @tab X @tab X
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@item Redirector                @tab   @tab X
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@item Renderware TeXture Dictionary @tab   @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 RPL/ARMovie               @tab   @tab X
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@item RTP                       @tab   @tab X
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@item RTSP                      @tab   @tab X
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@item SDP                       @tab   @tab X
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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 Sierra SOL                @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 Smacker                   @tab   @tab X
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    @tab Multimedia format used by many games.
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@item Sony OpenMG (OMA)         @tab   @tab X
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    @tab Audio format used in Sony Sonic Stage and Sony Vegas.
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@item Sony PlayStation STR      @tab   @tab X
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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 Tiertex Limited 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 True Audio                @tab   @tab X
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@item VC-1 test bitstream       @tab X @tab X
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@item WAV                       @tab X @tab X
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@item WavPack                   @tab   @tab X
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@item Wing Commander III 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 audio    @tab   @tab X
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    @tab Multimedia format used in Westwood Studios games.
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@item Westwood Studios VQA      @tab   @tab X
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    @tab Multimedia format used in Westwood Studios games.
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@item YUV4MPEG pipe             @tab X @tab X
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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
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    @tab one raw file per component
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@item animated GIF @tab X @tab X
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    @tab Only uncompressed GIFs are generated.
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@item BMP          @tab X @tab X
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    @tab Microsoft BMP image
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@item JPEG         @tab X @tab X
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    @tab Progressive JPEG is not supported.
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@item JPEG 2000    @tab   @tab E
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    @tab decoding supported through external library libopenjpeg
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@item JPEG-LS      @tab X @tab X
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@item LJPEG        @tab X @tab
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    @tab Lossless JPEG
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@item PAM          @tab X @tab X
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    @tab PAM is a PNM extension with alpha support.
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@item PBM          @tab X @tab X
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    @tab Portable BitMap image
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@item PCX          @tab   @tab X
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    @tab PC Paintbrush
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@item PGM          @tab X @tab X
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    @tab Portable GrayMap image
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@item PGMYUV       @tab X @tab X
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    @tab PGM with U and V components in YUV 4:2:0
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@item PNG          @tab X @tab X
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    @tab 2/4 bpp not supported yet
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@item PPM          @tab X @tab X
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    @tab Portable PixelMap image
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@item PTX          @tab   @tab X
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    @tab V.Flash PTX format
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@item SGI          @tab X @tab X
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    @tab SGI RGB image format
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@item Sun Rasterfile  @tab   @tab X
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    @tab Sun RAS image format
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@item TIFF         @tab X @tab X
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    @tab YUV, JPEG and some extension is not supported yet.
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@item Truevision Targa  @tab X @tab X
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    @tab Targa (.TGA) image format
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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 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 Movie               @tab     @tab  X
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    @tab Used in certain computer games.
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@item 8SVX exponential       @tab     @tab  X
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@item 8SVX fibonacci         @tab     @tab  X
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@item American Laser Games MM  @tab    @tab X
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    @tab Used in games like Mad Dog McCree.
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@item AMV Video              @tab     @tab  X
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    @tab Used in Chinese MP3 players.
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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 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 Animator Flic video  @tab     @tab  X
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@item Autodesk RLE           @tab     @tab  X
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    @tab fourcc: AASC
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@item AVS (Audio Video Standard) video  @tab     @tab  X
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    @tab Video encoding used by the Creature Shock game.
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@item Beam Software VB       @tab     @tab  X
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@item Bethesda VID video     @tab     @tab  X
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    @tab Used in some games from Bethesda Softworks.
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@item Brute Force & Ignorance   @tab   @tab X
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    @tab Used in the game Flash Traffic: City of Angels.
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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 Chinese AVS video      @tab     @tab  X
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    @tab AVS1-P2, JiZhun profile
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@item Delphine Software International CIN video  @tab     @tab  X
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    @tab Codec used in Delphine Software International 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 (CYUV)    @tab     @tab  X
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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 DNxHD                  @tab   X @tab  X
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    @tab aka SMPTE VC3
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@item Duck TrueMotion 1.0   @tab     @tab  X
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    @tab fourcc: DUCK
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@item Duck TrueMotion 2.0    @tab     @tab  X
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    @tab fourcc: TM20
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@item DV (Digital Video)     @tab  X  @tab  X
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@item Feeble Files/ScummVM DXA  @tab     @tab  X
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    @tab Codec originally used in Feeble Files game.
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@item Electronic Arts CMV video  @tab     @tab  X
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    @tab Used in NHL 95 game.
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@item Electronic Arts TGV video  @tab     @tab  X
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@item Electronic Arts TGQ video  @tab     @tab  X
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@item Electronic Arts TQI video  @tab     @tab  X
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@item Escape 124             @tab     @tab  X
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@item FFmpeg codec #1        @tab  X  @tab  X
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    @tab experimental lossless codec (fourcc: FFV1)
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@item Flash Screen Video v1  @tab  X  @tab  X
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    @tab fourcc: FSV1
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@item Flash Video (FLV)      @tab  X  @tab  X
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    @tab Sorenson H.263 used in Flash
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@item Fraps                  @tab     @tab  X
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@item H.261                  @tab  X  @tab  X
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@item H.263 / H.263-1996     @tab  X  @tab  X
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@item H.263+ / H.263-1998 / H.263 version 2  @tab  X  @tab  X
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@item H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10  @tab  E  @tab  X
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    @tab encoding supported through external library libx264
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@item H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10 (VDPAU acceleration)  @tab  E  @tab  X
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@item HuffYUV                @tab  X  @tab  X
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@item HuffYUV FFmpeg variant @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 video           @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 H.263            @tab     @tab  X
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@item Intel Indeo 2          @tab     @tab  X
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@item Intel Indeo 3          @tab     @tab  X
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@item Interplay C93          @tab     @tab  X
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    @tab Used in the game Cyberia from Interplay.
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@item Interplay MVE video    @tab     @tab  X
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    @tab Used in Interplay .MVE files.
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@item Karl Morton's video codec  @tab     @tab  X
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    @tab Codec used in Worms games.
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@item LCL (LossLess Codec Library) MSZH  @tab     @tab  X
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@item LCL (LossLess Codec Library) ZLIB  @tab  E  @tab  E
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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 (Motion JPEG)    @tab  X  @tab  X
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@item Motion Pixels video    @tab     @tab  X
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@item MPEG-1 video           @tab  X  @tab  X
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@item MPEG-1/2 video XvMC (X-Video Motion Compensation)  @tab     @tab  X
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@item MPEG-1/2 video (VDPAU acceleration)  @tab     @tab  X
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@item MPEG-2 video           @tab  X  @tab  X
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@item MPEG-4 part 2          @tab  X  @tab  X
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    @ libxvidcore can be used alternatively for encoding.
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@item MPEG-4 part 2 Microsoft variant version 1  @tab  X  @tab  X
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@item MPEG-4 part 2 Microsoft variant version 2  @tab  X  @tab  X
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@item MPEG-4 part 2 Microsoft variant version 3  @tab  X  @tab  X
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@item Nintendo Gamecube THP video  @tab     @tab  X
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@item NuppelVideo/RTjpeg     @tab     @tab  X
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    @tab Video encoding used in NuppelVideo files.
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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 Q-team QPEG            @tab     @tab  X
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    @tab fourccs: QPEG, Q1.0, Q1.1
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@item QuickTime 8BPS video   @tab     @tab  X
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@item QuickTime Animation (RLE) video  @tab  X  @tab  X
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    @tab fourcc: 'rle '
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@item QuickTime Graphics (SMC)  @tab     @tab  X
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    @tab fourcc: 'smc '
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@item QuickTime video (RPZA) @tab     @tab  X
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    @tab fourcc: rpza
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@item Raw Video              @tab  X  @tab  X
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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 (TeXture Dictionary)  @tab     @tab  X
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    @tab Texture dictionaries used by the Renderware Engine.
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@item RL2 video              @tab     @tab  X
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    @tab used in some games by Entertainment Software Partners
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@item Sierra VMD video       @tab     @tab  X
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    @tab Used in Sierra VMD 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 SMPTE VC-1             @tab     @tab  X
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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 (Motion DECoder)  @tab     @tab  X
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@item Sorenson Vector Quantizer 1  @tab  X  @tab  X
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    @tab fourcc: SVQ1
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@item Sorenson Vector Quantizer 3  @tab     @tab  X
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    @tab fourcc: SVQ3
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@item Sunplus JPEG (SP5X)    @tab     @tab  X
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    @tab fourcc: SP5X
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@item TechSmith Screen Capture Codec  @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 Tiertex Limited SEQ video  @tab     @tab  X
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    @tab Codec used in DOS CD-ROM FlashBack game.
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@item VMware Screen Codec / VMware Video  @tab     @tab  X
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    @tab Codec used in videos captured by VMware.
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@item Westwood Studios VQA (Vector Quantized Animation) video  @tab     @tab  X
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@item Windows Media Video 7  @tab  X  @tab  X
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@item Windows Media Video 8  @tab  X  @tab  X
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@item Windows Media Video 9  @tab     @tab  X
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    @tab not completely working
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@item Wing Commander III / Xan  @tab     @tab  X
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    @tab Used in Wing Commander III .MVE files.
451
@item Winnov WNV1            @tab     @tab  X
452
@item WMV7                   @tab  X  @tab  X
453
@item YAMAHA SMAF            @tab  X  @tab  X
454
@item ZLIB                   @tab  X  @tab  X
455
    @tab part of LCL, encoder experimental
456
@item Zip Motion Blocks Video  @tab   X @tab  X
457
    @tab Encoder works only in PAL8.
458
@end multitable
459

    
460
@code{X} means that encoding (resp. decoding) is supported.
461

    
462
@code{E} means that support is provided through an external library.
463

    
464
@section Audio Codecs
465

    
466
@multitable @columnfractions .4 .1 .1 .4
467
@item Name @tab Encoding @tab Decoding @tab Comments
468
@item 8SVX audio             @tab     @tab  X
469
@item AAC                    @tab  E  @tab  X
470
    @tab encoding supported through external library libfaac
471
@item AC-3                   @tab IX  @tab  X
472
@item ADPCM 4X Movie         @tab     @tab  X
473
@item ADPCM CDROM XA         @tab     @tab  X
474
@item ADPCM Creative Technology @tab     @tab  X
475
    @tab 16 -> 4, 8 -> 4, 8 -> 3, 8 -> 2
476
@item ADPCM Electronic Arts  @tab     @tab  X
477
    @tab Used in various EA titles.
478
@item ADPCM Electronic Arts Maxis CDROM XS  @tab     @tab  X
479
    @tab Used in Sim City 3000.
480
@item ADPCM Electronic Arts R1  @tab     @tab  X
481
@item ADPCM Electronic Arts R2  @tab     @tab  X
482
@item ADPCM Electronic Arts R3  @tab     @tab  X
483
@item ADPCM Electronic Arts XAS @tab     @tab  X
484
@item ADPCM G.726            @tab  X  @tab  X
485
@item ADPCM IMA AMV          @tab     @tab  X
486
    @tab Used in AMV files
487
@item ADPCM IMA Electronic Arts EACS  @tab     @tab  X
488
@item ADPCM IMA Electronic Arts SEAD  @tab     @tab  X
489
@item ADPCM IMA Funcom       @tab     @tab  X
490
@item ADPCM IMA QuickTime    @tab  X  @tab  X
491
@item ADPCM IMA Loki SDL MJPEG  @tab     @tab  X
492
@item ADPCM IMA WAV          @tab  X  @tab  X
493
@item ADPCM IMA Westwood     @tab     @tab  X
494
@item ADPCM ISS IMA          @tab     @tab  X
495
    @tab Used in FunCom games.
496
@item ADPCM IMA Duck DK3     @tab     @tab  X
497
    @tab Used in some Sega Saturn console games.
498
@item ADPCM IMA Duck DK4     @tab     @tab  X
499
    @tab Used in some Sega Saturn console games.
500
@item ADPCM Microsoft        @tab  X  @tab  X
501
@item ADPCM MS IMA           @tab  X  @tab  X
502
@item ADPCM Nintendo Gamecube THP  @tab     @tab  X
503
@item ADPCM QT IMA           @tab  X  @tab  X
504
@item ADPCM SEGA CRI ADX     @tab  X  @tab  X
505
    @tab Used in Sega Dreamcast games.
506
@item ADPCM Shockwave Flash  @tab  X  @tab  X
507
@item ADPCM SMJPEG IMA       @tab     @tab  X
508
    @tab Used in certain Loki game ports.
509
@item ADPCM Sound Blaster Pro 2-bit  @tab     @tab  X
510
@item ADPCM Sound Blaster Pro 2.6-bit  @tab     @tab  X
511
@item ADPCM Sound Blaster Pro 4-bit  @tab     @tab  X
512
@item ADPCM Westwood Studios IMA @tab     @tab  X
513
    @tab Used in Westwood Studios games like Command and Conquer.
514
@item ADPCM Yamaha           @tab  X  @tab  X
515
@item AMR-NB                 @tab  E  @tab  E
516
    @tab supported through external library libamrnb
517
@item AMR-WB                 @tab  E  @tab  E
518
    @tab supported through external library libamrwb
519
@item Apple lossless audio   @tab  X  @tab  X
520
    @tab QuickTime fourcc 'alac'
521
@item Atrac 3                @tab     @tab  X
522
@item Delphine Software International CIN audio  @tab     @tab  X
523
    @tab Codec used in Delphine Software International games.
524
@item COOK                   @tab     @tab  X
525
    @tab All versions except 5.1 are supported.
526
@item DCA (DTS Coherent Acoustics)  @tab     @tab  X
527
@item DPCM id RoQ            @tab  X  @tab  X
528
    @tab Used in Quake III, Jedi Knight 2, other computer games.
529
@item DPCM Interplay         @tab     @tab  X
530
    @tab Used in various Interplay computer games.
531
@item DPCM Sierra Online     @tab     @tab  X
532
    @tab Used in Sierra Online game audio files.
533
@item DPCM Sol               @tab     @tab  X
534
@item DPCM Xan               @tab     @tab  X
535
@item DSP Group TrueSpeech   @tab     @tab  X
536
@item DV audio               @tab     @tab  X
537
@item Enhanced AC-3          @tab     @tab  X
538
@item FLAC (Free Lossless Audio Codec)  @tab  X  @tab  IX
539
@item G.729                  @tab     @tab  X
540
@item GSM                    @tab  E  @tab  E
541
    @tab supported through external library libgsm
542
@item GSM Microsoft variant  @tab  E  @tab  E
543
    @tab supported through external library libgsm
544
@item IMC (Intel Music Coder)  @tab     @tab  X
545
@item MACE (Macintosh Audio Compression/Expansion) 3:1  @tab     @tab  X
546
@item MACE (Macintosh Audio Compression/Expansion) 6:1  @tab     @tab  X
547
@item MLP(Meridian Lossless Packing)/TrueHD  @tab     @tab  X
548
    @tab Used in DVD-Audio and Blu-Ray discs.
549
@item Monkey's Audio         @tab     @tab  X
550
    @tab Only versions 3.97-3.99 are supported.
551
@item MP1 (MPEG audio layer 1)  @tab     @tab IX
552
@item MP2 (MPEG audio layer 2)  @tab IX  @tab IX
553
@item MP3 (MPEG audio layer 3)  @tab  E  @tab IX
554
    @tab encoding supported through external library LAME, ADU MP3 and MP3onMP4 also supported
555
@item Musepack SV7           @tab     @tab  X
556
@item Musepack SV8           @tab     @tab  X
557
@item Nellymoser Asao        @tab  X  @tab  X
558
@item PCM A-law              @tab  X  @tab  X
559
@item PCM mu-law             @tab  X  @tab  X
560
@item PCM 16-bit little-endian planar  @tab     @tab  X
561
@item PCM 32-bit floating point big-endian  @tab  X  @tab  X
562
@item PCM 32-bit floating point little-endian  @tab  X  @tab  X
563
@item PCM 64-bit floating point big-endian  @tab  X  @tab  X
564
@item PCM 64-bit floating point little-endian  @tab  X  @tab  X
565
@item PCM D-Cinema audio signed 24-bit   @tab  X  @tab  X
566
@item PCM signed 8-bit       @tab  X  @tab  X
567
@item PCM signed 16-bit big-endian  @tab  X  @tab  X
568
@item PCM signed 16-bit little-endian  @tab  X  @tab  X
569
@item PCM signed 24-bit big-endian  @tab  X  @tab  X
570
@item PCM signed 24-bit little-endian  @tab  X  @tab  X
571
@item PCM signed 32-bit big-endian  @tab  X  @tab  X
572
@item PCM signed 32-bit little-endian  @tab  X  @tab  X
573
@item PCM unsigned 8-bit     @tab  X  @tab  X
574
@item PCM unsigned 16-bit big-endian  @tab  X  @tab  X
575
@item PCM unsigned 16-bit little-endian  @tab  X  @tab  X
576
@item PCM unsigned 24-bit big-endian  @tab  X  @tab  X
577
@item PCM unsigned 24-bit little-endian  @tab  X  @tab  X
578
@item PCM unsigned 32-bit big-endian  @tab  X  @tab  X
579
@item PCM unsigned 32-bit little-endian  @tab  X  @tab  X
580
@item PCM Zork               @tab  X  @tab  X
581
@item QCELP / PureVoice      @tab     @tab  X
582
@item QDesign Music Codec 2  @tab     @tab  X
583
    @tab There are still some distortions.
584
@item RealAudio 1.0 (14.4K)  @tab     @tab  X
585
    @tab Real 14400 bit/s codec
586
@item RealAudio 2.0 (28.8K)  @tab     @tab  X
587
    @tab Real 28800 bit/s codec
588
@item RealAudio 3.0 (dnet)   @tab IX  @tab  X
589
    @tab Real low bitrate AC-3 codec
590
@item Shorten                @tab     @tab  X
591
@item Sierra VMD audio       @tab     @tab  X
592
    @tab Used in Sierra VMD files.
593
@item Smacker audio          @tab     @tab  X
594
@item Sonic                  @tab  X  @tab  X
595
    @tab experimental codec
596
@item Sonic lossless         @tab  X  @tab  X
597
    @tab experimental codec
598
@item Speex                  @tab     @tab  E
599
    @tab supported through external library libspeex
600
@item True Audio (TTA)       @tab     @tab  X
601
@item Vorbis                 @tab  E  @tab  X
602
    @ A native but very primitive encoder exists.
603
@item WavPack                @tab     @tab  X
604
@item Westwood Audio (SND1)  @tab     @tab  X
605
@item Windows Media Audio 1  @tab  X  @tab  X
606
@item Windows Media Audio 2  @tab  X  @tab  X
607
    @tab Used in Origin's Wing Commander IV AVI files.
608
@end multitable
609

    
610
@code{X} means that encoding (resp. decoding) is supported.
611

    
612
@code{E} means that support is provided through an external library.
613

    
614
@code{I} means that an integer-only version is available, too (ensures high
615
performance on systems without hardware floating point support).
616

    
617
@section Subtitle Formats
618

    
619
@multitable @columnfractions .4 .1 .1 .1 .1
620
@item Name @tab Muxing @tab Demuxing @tab Encoding @tab Decoding
621
@item SSA/ASS      @tab X @tab X
622
@item DVB          @tab X @tab X @tab X @tab X
623
@item DVD          @tab X @tab X @tab X @tab X
624
@item XSUB         @tab   @tab   @tab   @tab X
625
@end multitable
626

    
627
@code{X} means that the feature is supported.
628

    
629
@section Network Protocols
630

    
631
@multitable @columnfractions .4 .1
632
@item Name         @tab Support
633
@item file         @tab X
634
@item Gopher       @tab X
635
@item HTTP         @tab X
636
@item pipe         @tab X
637
@item RTP          @tab X
638
@item TCP          @tab X
639
@item UDP          @tab X
640
@end multitable
641

    
642
@code{X} means that the protocol is supported.
643

    
644

    
645
@section Input/Output Devices
646

    
647
@multitable @columnfractions .4 .1 .1
648
@item Name              @tab Input  @tab Output
649
@item ALSA              @tab X      @tab X
650
@item BEOS audio        @tab X      @tab X
651
@item BKTR              @tab X      @tab
652
@item DV1394            @tab X      @tab
653
@item LIBDC1394         @tab X      @tab
654
@item OSS               @tab X      @tab X
655
@item Video4Linux       @tab X      @tab
656
@item Video4Linux2      @tab X      @tab
657
@item VfW capture       @tab X      @tab
658
@item X11 grabbing      @tab X      @tab
659
@end multitable
660

    
661
@code{X} means that the protocol is supported.
662

    
663

    
664
@chapter Platform Specific information
665

    
666
@section BSD
667

    
668
BSD make will not build FFmpeg, you need to install and use GNU Make
669
(@file{gmake}).
670

    
671
@section Windows
672

    
673
To get help and instructions for building FFmpeg under Windows, check out
674
the FFmpeg Windows Help Forum at
675
@url{http://ffmpeg.arrozcru.org/}.
676

    
677
@subsection Native Windows compilation
678

    
679
FFmpeg can be built to run natively on Windows using the MinGW tools. Install
680
the latest versions of MSYS and MinGW from @url{http://www.mingw.org/}.
681
You can find detailed installation
682
instructions in the download section and the FAQ.
683

    
684
FFmpeg does not build out-of-the-box with the packages the automated MinGW
685
installer provides. It also requires coreutils to be installed and many other
686
packages updated to the latest version. The minimum version for some packages
687
are listed below:
688

    
689
@itemize
690
@item bash 3.1
691
@item msys-make 3.81-2 (note: not mingw32-make)
692
@item w32api 3.13
693
@item mingw-runtime 3.15
694
@end itemize
695

    
696
You will also need to pass @code{-fno-common} to the compiler to work around
697
a GCC bug (see @url{http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37216}).
698

    
699
Within the MSYS shell, configure and make with:
700

    
701
@example
702
./configure --enable-memalign-hack --extra-cflags=-fno-common
703
make
704
make install
705
@end example
706

    
707
This will install @file{ffmpeg.exe} along with many other development files
708
to @file{/usr/local}. You may specify another install path using the
709
@code{--prefix} option in @file{configure}.
710

    
711
Notes:
712

    
713
@itemize
714

    
715
@item In order to compile FFplay, you must have the MinGW development library
716
of SDL. Get it from @url{http://www.libsdl.org}.
717
Edit the @file{bin/sdl-config} script so that it points to the correct prefix
718
where SDL was installed. Verify that @file{sdl-config} can be launched from
719
the MSYS command line.
720

    
721
@item By using @code{./configure --enable-shared} when configuring FFmpeg,
722
you can build libavutil, libavcodec and libavformat as DLLs.
723

    
724
@end itemize
725

    
726
@subsection Microsoft Visual C++ compatibility
727

    
728
As stated in the FAQ, FFmpeg will not compile under MSVC++. However, if you
729
want to use the libav* libraries in your own applications, you can still
730
compile those applications using MSVC++. But the libav* libraries you link
731
to @emph{must} be built with MinGW. However, you will not be able to debug
732
inside the libav* libraries, since MSVC++ does not recognize the debug
733
symbols generated by GCC.
734
We strongly recommend you to move over from MSVC++ to MinGW tools.
735

    
736
This description of how to use the FFmpeg libraries with MSVC++ is based on
737
Microsoft Visual C++ 2005 Express Edition. If you have a different version,
738
you might have to modify the procedures slightly.
739

    
740
@subsubsection Using static libraries
741

    
742
Assuming you have just built and installed FFmpeg in @file{/usr/local}.
743

    
744
@enumerate
745

    
746
@item Create a new console application ("File / New / Project") and then
747
select "Win32 Console Application". On the appropriate page of the
748
Application Wizard, uncheck the "Precompiled headers" option.
749

    
750
@item Write the source code for your application, or, for testing, just
751
copy the code from an existing sample application into the source file
752
that MSVC++ has already created for you. For example, you can copy
753
@file{output_example.c} from the FFmpeg distribution.
754

    
755
@item Open the "Project / Properties" dialog box. In the "Configuration"
756
combo box, select "All Configurations" so that the changes you make will
757
affect both debug and release builds. In the tree view on the left hand
758
side, select "C/C++ / General", then edit the "Additional Include
759
Directories" setting to contain the path where the FFmpeg includes were
760
installed (i.e. @file{c:\msys\1.0\local\include}).
761
Do not add MinGW's include directory here, or the include files will
762
conflict with MSVC's.
763

    
764
@item Still in the "Project / Properties" dialog box, select
765
"Linker / General" from the tree view and edit the
766
"Additional Library Directories" setting to contain the @file{lib}
767
directory where FFmpeg was installed (i.e. @file{c:\msys\1.0\local\lib}),
768
the directory where MinGW libs are installed (i.e. @file{c:\mingw\lib}),
769
and the directory where MinGW's GCC libs are installed
770
(i.e. @file{C:\mingw\lib\gcc\mingw32\4.2.1-sjlj}). Then select
771
"Linker / Input" from the tree view, and add the files @file{libavformat.a},
772
@file{libavcodec.a}, @file{libavutil.a}, @file{libmingwex.a},
773
@file{libgcc.a}, and any other libraries you used (i.e. @file{libz.a})
774
to the end of "Additional Dependencies".
775

    
776
@item Now, select "C/C++ / Code Generation" from the tree view. Select
777
"Debug" in the "Configuration" combo box. Make sure that "Runtime
778
Library" is set to "Multi-threaded Debug DLL". Then, select "Release" in
779
the "Configuration" combo box and make sure that "Runtime Library" is
780
set to "Multi-threaded DLL".
781

    
782
@item Click "OK" to close the "Project / Properties" dialog box.
783

    
784
@item MSVC++ lacks some C99 header files that are fundamental for FFmpeg.
785
Get msinttypes from @url{http://code.google.com/p/msinttypes/downloads/list}
786
and install it in MSVC++'s include directory
787
(i.e. @file{C:\Program Files\Microsoft Visual Studio 8\VC\include}).
788

    
789
@item MSVC++ also does not understand the @code{inline} keyword used by
790
FFmpeg, so you must add this line before @code{#include}ing libav*:
791
@example
792
#define inline _inline
793
@end example
794

    
795
@item Build your application, everything should work.
796

    
797
@end enumerate
798

    
799
@subsubsection Using shared libraries
800

    
801
This is how to create DLL and LIB files that are compatible with MSVC++:
802

    
803
@enumerate
804

    
805
@item Add a call to @file{vcvars32.bat} (which sets up the environment
806
variables for the Visual C++ tools) as the first line of @file{msys.bat}.
807
The standard location for @file{vcvars32.bat} is
808
@file{C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat},
809
and the standard location for @file{msys.bat} is @file{C:\msys\1.0\msys.bat}.
810
If this corresponds to your setup, add the following line as the first line
811
of @file{msys.bat}:
812

    
813
@example
814
call "C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat"
815
@end example
816

    
817
Alternatively, you may start the @file{Visual Studio 2005 Command Prompt},
818
and run @file{c:\msys\1.0\msys.bat} from there.
819

    
820
@item Within the MSYS shell, run @code{lib.exe}. If you get a help message
821
from @file{Microsoft (R) Library Manager}, this means your environment
822
variables are set up correctly, the @file{Microsoft (R) Library Manager}
823
is on the path and will be used by FFmpeg to create
824
MSVC++-compatible import libraries.
825

    
826
@item Build FFmpeg with
827

    
828
@example
829
./configure --enable-shared --enable-memalign-hack
830
make
831
make install
832
@end example
833

    
834
Your install path (@file{/usr/local/} by default) should now have the
835
necessary DLL and LIB files under the @file{bin} directory.
836

    
837
@end enumerate
838

    
839
To use those files with MSVC++, do the same as you would do with
840
the static libraries, as described above. But in Step 4,
841
you should only need to add the directory where the LIB files are installed
842
(i.e. @file{c:\msys\usr\local\bin}). This is not a typo, the LIB files are
843
installed in the @file{bin} directory. And instead of adding @file{libxx.a}
844
files, you should add @file{avcodec.lib}, @file{avformat.lib}, and
845
@file{avutil.lib}. There should be no need for @file{libmingwex.a},
846
@file{libgcc.a}, and @file{wsock32.lib}, nor any other external library
847
statically linked into the DLLs. The @file{bin} directory contains a bunch
848
of DLL files, but the ones that are actually used to run your application
849
are the ones with a major version number in their filenames
850
(i.e. @file{avcodec-51.dll}).
851

    
852
@subsection Cross compilation for Windows with Linux
853

    
854
You must use the MinGW cross compilation tools available at
855
@url{http://www.mingw.org/}.
856

    
857
Then configure FFmpeg with the following options:
858
@example
859
./configure --target-os=mingw32 --cross-prefix=i386-mingw32msvc-
860
@end example
861
(you can change the cross-prefix according to the prefix chosen for the
862
MinGW tools).
863

    
864
Then you can easily test FFmpeg with Wine
865
(@url{http://www.winehq.com/}).
866

    
867
@subsection Compilation under Cygwin
868

    
869
The main issue with the 1.5.x Cygwin versions is that newlib, its C library,
870
does not contain llrint().  You need to upgrade to the unstable 1.7.x versions,
871
or leverage the implementation in MinGW (as explained below).
872

    
873
Just install your Cygwin with all the "Base" packages, plus the
874
following "Devel" ones:
875
@example
876
binutils, gcc-core, make, subversion, mingw-runtime, diffutils
877
@end example
878

    
879
The experimental gcc4 package is still buggy, hence please
880
use the official gcc 3.4.4 or a 4.2.x compiled from source by yourself.
881

    
882
Install the current binutils-20080624-2 as they work fine (the old
883
binutils-20060709-1 proved buggy on shared builds).
884

    
885
Then create a small library that just contains llrint():
886

    
887
@example
888
ar x /usr/lib/mingw/libmingwex.a llrint.o
889
ar cq /usr/local/lib/libllrint.a llrint.o
890
@end example
891

    
892
Then run
893

    
894
@example
895
./configure --enable-static --disable-shared  --extra-ldflags='-L /usr/local/lib' --extra-libs='-l llrint'
896
@end example
897

    
898
to make a static build or
899

    
900
@example
901
./configure --enable-shared --disable-static  --extra-ldflags='-L /usr/local/lib' --extra-libs='-l llrint'
902
@end example
903

    
904
to build shared libraries.
905

    
906
If you want to build FFmpeg with additional libraries, download Cygwin
907
"Devel" packages for Ogg and Vorbis from any Cygwin packages repository:
908
@example
909
libogg-devel, libvorbis-devel
910
@end example
911

    
912
These library packages are only available from Cygwin Ports
913
(@url{http://sourceware.org/cygwinports/}) :
914

    
915
@example
916
yasm, libSDL-devel, libdirac-devel, libfaac-devel, libfaad-devel, libgsm-devel,
917
libmp3lame-devel, libschroedinger1.0-devel, speex-devel, libtheora-devel,
918
libxvidcore-devel
919
@end example
920

    
921
The recommendation for libnut and x264 is to build them from source by
922
yourself, as they evolve too quickly for Cygwin Ports to be up to date.
923

    
924
Cygwin 1.7.x has IPv6 support. You can add IPv6 to Cygwin 1.5.x by means
925
of the @code{libgetaddrinfo-devel} package, available at Cygwin Ports.
926

    
927
@subsection Crosscompilation for Windows under Cygwin
928

    
929
With Cygwin you can create Windows binaries that do not need the cygwin1.dll.
930

    
931
Just install your Cygwin as explained before, plus these additional
932
"Devel" packages:
933
@example
934
gcc-mingw-core, mingw-runtime, mingw-zlib
935
@end example
936

    
937
and add some special flags to your configure invocation.
938

    
939
For a static build run
940
@example
941
./configure --target-os=mingw32 --enable-memalign-hack --enable-static --disable-shared --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
942
@end example
943

    
944
and for a build with shared libraries
945
@example
946
./configure --target-os=mingw32 --enable-memalign-hack --enable-shared --disable-static --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
947
@end example
948

    
949
@section BeOS
950

    
951
BeOS support is broken in mysterious ways.
952

    
953
@section OS/2
954

    
955
For information about compiling FFmpeg on OS/2 see
956
@url{http://www.edm2.com/index.php/FFmpeg}.
957

    
958
@chapter Developers Guide
959

    
960
@section API
961
@itemize @bullet
962
@item libavcodec is the library containing the codecs (both encoding and
963
decoding). Look at @file{libavcodec/apiexample.c} to see how to use it.
964

    
965
@item libavformat is the library containing the file format handling (mux and
966
demux code for several formats). Look at @file{ffplay.c} to use it in a
967
player. See @file{output_example.c} to use it to generate audio or video
968
streams.
969

    
970
@end itemize
971

    
972
@section Integrating libavcodec or libavformat in your program
973

    
974
You can integrate all the source code of the libraries to link them
975
statically to avoid any version problem. All you need is to provide a
976
'config.mak' and a 'config.h' in the parent directory. See the defines
977
generated by ./configure to understand what is needed.
978

    
979
You can use libavcodec or libavformat in your commercial program, but
980
@emph{any patch you make must be published}. The best way to proceed is
981
to send your patches to the FFmpeg mailing list.
982

    
983
@node Coding Rules
984
@section Coding Rules
985

    
986
FFmpeg is programmed in the ISO C90 language with a few additional
987
features from ISO C99, namely:
988
@itemize @bullet
989
@item
990
the @samp{inline} keyword;
991
@item
992
@samp{//} comments;
993
@item
994
designated struct initializers (@samp{struct s x = @{ .i = 17 @};})
995
@item
996
compound literals (@samp{x = (struct s) @{ 17, 23 @};})
997
@end itemize
998

    
999
These features are supported by all compilers we care about, so we will not
1000
accept patches to remove their use unless they absolutely do not impair
1001
clarity and performance.
1002

    
1003
All code must compile with GCC 2.95 and GCC 3.3. Currently, FFmpeg also
1004
compiles with several other compilers, such as the Compaq ccc compiler
1005
or Sun Studio 9, and we would like to keep it that way unless it would
1006
be exceedingly involved. To ensure compatibility, please do not use any
1007
additional C99 features or GCC extensions. Especially watch out for:
1008
@itemize @bullet
1009
@item
1010
mixing statements and declarations;
1011
@item
1012
@samp{long long} (use @samp{int64_t} instead);
1013
@item
1014
@samp{__attribute__} not protected by @samp{#ifdef __GNUC__} or similar;
1015
@item
1016
GCC statement expressions (@samp{(x = (@{ int y = 4; y; @})}).
1017
@end itemize
1018

    
1019
Indent size is 4.
1020
The presentation is the one specified by 'indent -i4 -kr -nut'.
1021
The TAB character is forbidden outside of Makefiles as is any
1022
form of trailing whitespace. Commits containing either will be
1023
rejected by the Subversion repository.
1024

    
1025
The main priority in FFmpeg is simplicity and small code size in order to
1026
minimize the bug count.
1027

    
1028
Comments: Use the JavaDoc/Doxygen
1029
format (see examples below) so that code documentation
1030
can be generated automatically. All nontrivial functions should have a comment
1031
above them explaining what the function does, even if it is just one sentence.
1032
All structures and their member variables should be documented, too.
1033
@example
1034
/**
1035
 * @@file mpeg.c
1036
 * MPEG codec.
1037
 * @@author ...
1038
 */
1039

    
1040
/**
1041
 * Summary sentence.
1042
 * more text ...
1043
 * ...
1044
 */
1045
typedef struct Foobar@{
1046
    int var1; /**< var1 description */
1047
    int var2; ///< var2 description
1048
    /** var3 description */
1049
    int var3;
1050
@} Foobar;
1051

    
1052
/**
1053
 * Summary sentence.
1054
 * more text ...
1055
 * ...
1056
 * @@param my_parameter description of my_parameter
1057
 * @@return return value description
1058
 */
1059
int myfunc(int my_parameter)
1060
...
1061
@end example
1062

    
1063
fprintf and printf are forbidden in libavformat and libavcodec,
1064
please use av_log() instead.
1065

    
1066
Casts should be used only when necessary. Unneeded parentheses
1067
should also be avoided if they don't make the code easier to understand.
1068

    
1069
@section Development Policy
1070

    
1071
@enumerate
1072
@item
1073
   Contributions should be licensed under the LGPL 2.1, including an
1074
   "or any later version" clause, or the MIT license.  GPL 2 including
1075
   an "or any later version" clause is also acceptable, but LGPL is
1076
   preferred.
1077
@item
1078
   You must not commit code which breaks FFmpeg! (Meaning unfinished but
1079
   enabled code which breaks compilation or compiles but does not work or
1080
   breaks the regression tests)
1081
   You can commit unfinished stuff (for testing etc), but it must be disabled
1082
   (#ifdef etc) by default so it does not interfere with other developers'
1083
   work.
1084
@item
1085
   You do not have to over-test things. If it works for you, and you think it
1086
   should work for others, then commit. If your code has problems
1087
   (portability, triggers compiler bugs, unusual environment etc) they will be
1088
   reported and eventually fixed.
1089
@item
1090
   Do not commit unrelated changes together, split them into self-contained
1091
   pieces. Also do not forget that if part B depends on part A, but A does not
1092
   depend on B, then A can and should be committed first and separate from B.
1093
   Keeping changes well split into self-contained parts makes reviewing and
1094
   understanding them on the commit log mailing list easier. This also helps
1095
   in case of debugging later on.
1096
   Also if you have doubts about splitting or not splitting, do not hesitate to
1097
   ask/discuss it on the developer mailing list.
1098
@item
1099
   Do not change behavior of the program (renaming options etc) without
1100
   first discussing it on the ffmpeg-devel mailing list. Do not remove
1101
   functionality from the code. Just improve!
1102

    
1103
   Note: Redundant code can be removed.
1104
@item
1105
   Do not commit changes to the build system (Makefiles, configure script)
1106
   which change behavior, defaults etc, without asking first. The same
1107
   applies to compiler warning fixes, trivial looking fixes and to code
1108
   maintained by other developers. We usually have a reason for doing things
1109
   the way we do. Send your changes as patches to the ffmpeg-devel mailing
1110
   list, and if the code maintainers say OK, you may commit. This does not
1111
   apply to files you wrote and/or maintain.
1112
@item
1113
   We refuse source indentation and other cosmetic changes if they are mixed
1114
   with functional changes, such commits will be rejected and removed. Every
1115
   developer has his own indentation style, you should not change it. Of course
1116
   if you (re)write something, you can use your own style, even though we would
1117
   prefer if the indentation throughout FFmpeg was consistent (Many projects
1118
   force a given indentation style - we do not.). If you really need to make
1119
   indentation changes (try to avoid this), separate them strictly from real
1120
   changes.
1121

    
1122
   NOTE: If you had to put if()@{ .. @} over a large (> 5 lines) chunk of code,
1123
   then either do NOT change the indentation of the inner part within (do not
1124
   move it to the right)! or do so in a separate commit
1125
@item
1126
   Always fill out the commit log message. Describe in a few lines what you
1127
   changed and why. You can refer to mailing list postings if you fix a
1128
   particular bug. Comments such as "fixed!" or "Changed it." are unacceptable.
1129
@item
1130
   If you apply a patch by someone else, include the name and email address in
1131
   the log message. Since the ffmpeg-cvslog mailing list is publicly
1132
   archived you should add some SPAM protection to the email address. Send an
1133
   answer to ffmpeg-devel (or wherever you got the patch from) saying that
1134
   you applied the patch.
1135
@item
1136
   When applying patches that have been discussed (at length) on the mailing
1137
   list, reference the thread in the log message.
1138
@item
1139
    Do NOT commit to code actively maintained by others without permission.
1140
    Send a patch to ffmpeg-devel instead. If no one answers within a reasonable
1141
    timeframe (12h for build failures and security fixes, 3 days small changes,
1142
    1 week for big patches) then commit your patch if you think it is OK.
1143
    Also note, the maintainer can simply ask for more time to review!
1144
@item
1145
    Subscribe to the ffmpeg-cvslog mailing list. The diffs of all commits
1146
    are sent there and reviewed by all the other developers. Bugs and possible
1147
    improvements or general questions regarding commits are discussed there. We
1148
    expect you to react if problems with your code are uncovered.
1149
@item
1150
    Update the documentation if you change behavior or add features. If you are
1151
    unsure how best to do this, send a patch to ffmpeg-devel, the documentation
1152
    maintainer(s) will review and commit your stuff.
1153
@item
1154
    Try to keep important discussions and requests (also) on the public
1155
    developer mailing list, so that all developers can benefit from them.
1156
@item
1157
    Never write to unallocated memory, never write over the end of arrays,
1158
    always check values read from some untrusted source before using them
1159
    as array index or other risky things.
1160
@item
1161
    Remember to check if you need to bump versions for the specific libav
1162
    parts (libavutil, libavcodec, libavformat) you are changing. You need
1163
    to change the version integer.
1164
    Incrementing the first component means no backward compatibility to
1165
    previous versions (e.g. removal of a function from the public API).
1166
    Incrementing the second component means backward compatible change
1167
    (e.g. addition of a function to the public API or extension of an
1168
    existing data structure).
1169
    Incrementing the third component means a noteworthy binary compatible
1170
    change (e.g. encoder bug fix that matters for the decoder).
1171
@item
1172
    Compiler warnings indicate potential bugs or code with bad style. If a type of
1173
    warning always points to correct and clean code, that warning should
1174
    be disabled, not the code changed.
1175
    Thus the remaining warnings can either be bugs or correct code.
1176
    If it is a bug, the bug has to be fixed. If it is not, the code should
1177
    be changed to not generate a warning unless that causes a slowdown
1178
    or obfuscates the code.
1179
@item
1180
    If you add a new file, give it a proper license header. Do not copy and
1181
    paste it from a random place, use an existing file as template.
1182
@end enumerate
1183

    
1184
We think our rules are not too hard. If you have comments, contact us.
1185

    
1186
Note, these rules are mostly borrowed from the MPlayer project.
1187

    
1188
@section Submitting patches
1189

    
1190
First, (@pxref{Coding Rules}) above if you did not yet.
1191

    
1192
When you submit your patch, try to send a unified diff (diff '-up'
1193
option). We cannot read other diffs :-)
1194

    
1195
Also please do not submit a patch which contains several unrelated changes.
1196
Split it into separate, self-contained pieces. This does not mean splitting
1197
file by file. Instead, make the patch as small as possible while still
1198
keeping it as a logical unit that contains an individual change, even
1199
if it spans multiple files. This makes reviewing your patches much easier
1200
for us and greatly increases your chances of getting your patch applied.
1201

    
1202
Run the regression tests before submitting a patch so that you can
1203
verify that there are no big problems.
1204

    
1205
Patches should be posted as base64 encoded attachments (or any other
1206
encoding which ensures that the patch will not be trashed during
1207
transmission) to the ffmpeg-devel mailing list, see
1208
@url{http://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel}
1209

    
1210
It also helps quite a bit if you tell us what the patch does (for example
1211
'replaces lrint by lrintf'), and why (for example '*BSD isn't C99 compliant
1212
and has no lrint()')
1213

    
1214
Also please if you send several patches, send each patch as a separate mail,
1215
do not attach several unrelated patches to the same mail.
1216

    
1217
@section New codecs or formats checklist
1218

    
1219
@enumerate
1220
@item
1221
    Did you use av_cold for codec initialization and close functions?
1222
@item
1223
    Did you add a long_name under NULL_IF_CONFIG_SMALL to the AVCodec or
1224
    AVInputFormat/AVOutputFormat struct?
1225
@item
1226
    Did you bump the minor version number in @file{avcodec.h} or
1227
    @file{avformat.h}?
1228
@item
1229
    Did you register it in @file{allcodecs.c} or @file{allformats.c}?
1230
@item
1231
    Did you add the CodecID to @file{avcodec.h}?
1232
@item
1233
    If it has a fourcc, did you add it to @file{libavformat/riff.c},
1234
    even if it is only a decoder?
1235
@item
1236
    Did you add a rule to compile the appropriate files in the Makefile?
1237
    Remember to do this even if you're just adding a format to a file that is
1238
    already being compiled by some other rule, like a raw demuxer.
1239
@item
1240
    Did you add an entry to the table of supported formats or codecs in the
1241
    documentation?
1242
@item
1243
    Did you add an entry in the Changelog?
1244
@item
1245
    If it depends on a parser or a library, did you add that dependency in
1246
    configure?
1247
@item
1248
    Did you "svn add" the appropriate files before commiting?
1249
@end enumerate
1250

    
1251
@section patch submission checklist
1252

    
1253
@enumerate
1254
@item
1255
    Do the regression tests pass with the patch applied?
1256
@item
1257
    Does @code{make checkheaders} pass with the patch applied?
1258
@item
1259
    Is the patch a unified diff?
1260
@item
1261
    Is the patch against latest FFmpeg SVN?
1262
@item
1263
    Are you subscribed to ffmpeg-dev?
1264
    (the list is subscribers only due to spam)
1265
@item
1266
    Have you checked that the changes are minimal, so that the same cannot be
1267
    achieved with a smaller patch and/or simpler final code?
1268
@item
1269
    If the change is to speed critical code, did you benchmark it?
1270
@item
1271
    If you did any benchmarks, did you provide them in the mail?
1272
@item
1273
    Have you checked that the patch does not introduce buffer overflows or
1274
    other security issues?
1275
@item
1276
    Did you test your decoder or demuxer against damaged data? If no, see
1277
    tools/trasher and the noise bitstream filter. Your decoder or demuxer
1278
    should not crash or end in a (near) infinite loop when fed damaged data.
1279
@item
1280
    Is the patch created from the root of the source tree, so it can be
1281
    applied with @code{patch -p0}?
1282
@item
1283
    Does the patch not mix functional and cosmetic changes?
1284
@item
1285
    Did you add tabs or trailing whitespace to the code? Both are forbidden.
1286
@item
1287
    Is the patch attached to the email you send?
1288
@item
1289
    Is the mime type of the patch correct? It should be text/x-diff or
1290
    text/x-patch or at least text/plain and not application/octet-stream.
1291
@item
1292
    If the patch fixes a bug, did you provide a verbose analysis of the bug?
1293
@item
1294
    If the patch fixes a bug, did you provide enough information, including
1295
    a sample, so the bug can be reproduced and the fix can be verified?
1296
    Note please do not attach samples >100k to mails but rather provide a
1297
    URL, you can upload to ftp://upload.ffmpeg.org
1298
@item
1299
    Did you provide a verbose summary about what the patch does change?
1300
@item
1301
    Did you provide a verbose explanation why it changes things like it does?
1302
@item
1303
    Did you provide a verbose summary of the user visible advantages and
1304
    disadvantages if the patch is applied?
1305
@item
1306
    Did you provide an example so we can verify the new feature added by the
1307
    patch easily?
1308
@item
1309
    If you added a new file, did you insert a license header? It should be
1310
    taken from FFmpeg, not randomly copied and pasted from somewhere else.
1311
@item
1312
    You should maintain alphabetical order in alphabetically ordered lists as
1313
    long as doing so does not break API/ABI compatibility.
1314
@item
1315
    Lines with similar content should be aligned vertically when doing so
1316
    improves readability.
1317
@item
1318
    Did you provide a suggestion for a clear commit log message?
1319
@end enumerate
1320

    
1321
@section Patch review process
1322

    
1323
All patches posted to ffmpeg-devel will be reviewed, unless they contain a
1324
clear note that the patch is not for SVN.
1325
Reviews and comments will be posted as replies to the patch on the
1326
mailing list. The patch submitter then has to take care of every comment,
1327
that can be by resubmitting a changed patch or by discussion. Resubmitted
1328
patches will themselves be reviewed like any other patch. If at some point
1329
a patch passes review with no comments then it is approved, that can for
1330
simple and small patches happen immediately while large patches will generally
1331
have to be changed and reviewed many times before they are approved.
1332
After a patch is approved it will be committed to the repository.
1333

    
1334
We will review all submitted patches, but sometimes we are quite busy so
1335
especially for large patches this can take several weeks.
1336

    
1337
When resubmitting patches, please do not make any significant changes
1338
not related to the comments received during review. Such patches will
1339
be rejected. Instead, submit  significant changes or new features as
1340
separate patches.
1341

    
1342
@section Regression tests
1343

    
1344
Before submitting a patch (or committing to the repository), you should at least
1345
test that you did not break anything.
1346

    
1347
The regression tests build a synthetic video stream and a synthetic
1348
audio stream. These are then encoded and decoded with all codecs or
1349
formats. The CRC (or MD5) of each generated file is recorded in a
1350
result file. A 'diff' is launched to compare the reference results and
1351
the result file.
1352

    
1353
The regression tests then go on to test the FFserver code with a
1354
limited set of streams. It is important that this step runs correctly
1355
as well.
1356

    
1357
Run 'make test' to test all the codecs and formats.
1358

    
1359
Run 'make fulltest' to test all the codecs, formats and FFserver.
1360

    
1361
[Of course, some patches may change the results of the regression tests. In
1362
this case, the reference results of the regression tests shall be modified
1363
accordingly].
1364

    
1365
@bye