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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 FLV                       @tab X @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 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 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
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@item MP3                       @tab X @tab
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@item MPEG audio                @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 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 RAS          @tab   @tab X
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    @tab Sun Rasterfile
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@item SGI          @tab X @tab X
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    @tab SGI RGB image format
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@item Targa        @tab X @tab X
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    @tab Targa (.TGA) 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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@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 Video               @tab     @tab  X
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    @tab Used in certain computer games.
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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                    @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 Electronic Arts TQI    @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 YAMAHA SMAF            @tab  X  @tab  X
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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
470
    @tab 16 -> 4, 8 -> 4, 8 -> 3, 8 -> 2
471
@item CRI ADX ADPCM          @tab  X  @tab  X
472
    @tab Used in Sega Dreamcast games.
473
@item DSP Group TrueSpeech   @tab     @tab  X
474
@item DTS Coherent Audio     @tab     @tab  X
475
@item Duck DK3 IMA ADPCM     @tab     @tab  X
476
    @tab Used in some Sega Saturn console games.
477
@item Duck DK4 IMA ADPCM     @tab     @tab  X
478
    @tab Used in some Sega Saturn console games.
479
@item DV audio               @tab     @tab  X
480
@item Electronic Arts ADPCM  @tab     @tab  X
481
    @tab Used in various EA titles.
482
@item Enhanced AC-3          @tab     @tab  X
483
@item FLAC lossless audio    @tab IX  @tab  X
484
@item G.726  ADPCM           @tab  X  @tab  X
485
@item GSM                    @tab  E  @tab  E
486
    @tab supported through external library libgsm
487
@item GSM_MS                 @tab  E  @tab  E
488
    @tab supported through external library libgsm
489
@item id RoQ DPCM            @tab  X  @tab  X
490
    @tab Used in Quake III, Jedi Knight 2, other computer games.
491
@item Intel Music Coder      @tab     @tab  X
492
@item Interplay MVE DPCM     @tab     @tab  X
493
    @tab Used in various Interplay computer games.
494
@item ISS IMA ADPCM          @tab     @tab  X
495
    @tab Used in FunCom games.
496
@item MAXIS EA ADPCM         @tab     @tab  X
497
    @tab Used in Sim City 3000.
498
@item Microsoft ADPCM        @tab  X  @tab  X
499
@item MLP/TrueHD             @tab     @tab  X
500
    @tab Used in DVD-Audio and Blu-Ray discs.
501
@item Monkey's Audio         @tab     @tab  X
502
    @tab Only versions 3.97-3.99 are supported.
503
@item MPEG audio layer 3     @tab  E  @tab IX
504
    @tab encoding supported through external library LAME
505
@item MPEG audio layer 2     @tab IX  @tab IX
506
@item MS IMA ADPCM           @tab  X  @tab  X
507
@item Musepack               @tab     @tab  X
508
    @tab SV7 and SV8 are supported.
509
@item Nellymoser ASAO        @tab  X  @tab  X
510
@item QCELP / PureVoice      @tab     @tab  X
511
@item Qdesign QDM2           @tab     @tab  X
512
    @tab There are still some distortions.
513
@item QT IMA ADPCM           @tab  X  @tab  X
514
@item RA144                  @tab     @tab  X
515
    @tab Real 14400 bit/s codec
516
@item RA288                  @tab     @tab  X
517
    @tab Real 28800 bit/s codec
518
@item RADnet                 @tab IX  @tab IX
519
    @tab Real low bitrate AC-3 codec
520
@item Real COOK              @tab     @tab  X
521
    @tab All versions except 5.1 are supported.
522
@item Shorten                @tab     @tab  X
523
@item Sierra Online DPCM     @tab     @tab  X
524
    @tab Used in Sierra Online game audio files.
525
@item Smacker audio          @tab     @tab  X
526
@item SMJPEG IMA ADPCM       @tab     @tab  X
527
    @tab Used in certain Loki game ports.
528
@item Sonic                  @tab  X  @tab  X
529
    @tab experimental codec
530
@item Sonic lossless         @tab  X  @tab  X
531
    @tab experimental codec
532
@item Speex                  @tab     @tab  E
533
    @tab supported through external library libspeex
534
@item THP ADPCM              @tab     @tab  X
535
    @tab Used on the Nintendo GameCube.
536
@item True Audio (TTA)       @tab     @tab  X
537
@item Vorbis                 @tab  X  @tab  X
538
@item WavPack                @tab     @tab  X
539
@item Westwood Studios IMA ADPCM @tab     @tab  X
540
    @tab Used in Westwood Studios games like Command and Conquer.
541
@item WMA v1/v2              @tab  X  @tab  X
542
@item Xan DPCM               @tab     @tab  X
543
    @tab Used in Origin's Wing Commander IV AVI files.
544
@end multitable
545

    
546
@code{X} means that encoding (resp. decoding) is supported.
547

    
548
@code{E} means that support is provided through an external library.
549

    
550
@code{I} means that an integer-only version is available, too (ensures high
551
performance on systems without hardware floating point support).
552

    
553
@section Subtitle Formats
554

    
555
@multitable @columnfractions .4 .1 .1 .1 .1 .1
556
@item Name @tab Muxing @tab Demuxing @tab Encoding @tab Decoding
557
@item SSA/ASS      @tab X @tab X
558
@item DVB          @tab X @tab X @tab X @tab X
559
@item DVD          @tab X @tab X @tab X @tab X
560
@item XSUB         @tab   @tab   @tab   @tab X
561
@end multitable
562

    
563
@code{X} means that the feature is supported.
564

    
565
@section Network Protocols
566

    
567
@multitable @columnfractions .4 .1 .1 .1 .1 .1
568
@item Name         @tab Support
569
@item file         @tab X
570
@item Gopher       @tab X
571
@item HTTP         @tab X
572
@item pipe         @tab X
573
@item RTP          @tab X
574
@item TCP          @tab X
575
@item UDP          @tab X
576
@end multitable
577

    
578
@code{X} means that the protocol is supported.
579

    
580

    
581
@chapter Platform Specific information
582

    
583
@section BSD
584

    
585
BSD make will not build FFmpeg, you need to install and use GNU Make
586
(@file{gmake}).
587

    
588
@section Windows
589

    
590
To get help and instructions for building FFmpeg under Windows, check out
591
the FFmpeg Windows Help Forum at
592
@url{http://ffmpeg.arrozcru.org/}.
593

    
594
@subsection Native Windows compilation
595

    
596
FFmpeg can be built to run natively on Windows using the MinGW tools. Install
597
the latest versions of MSYS and MinGW from @url{http://www.mingw.org/}.
598
You can find detailed installation
599
instructions in the download section and the FAQ.
600

    
601
FFmpeg does not build out-of-the-box with the packages the automated MinGW
602
installer provides. It also requires coreutils to be installed and many other
603
packages updated to the latest version. The minimum version for some packages
604
are listed below:
605

    
606
@itemize
607
@item bash 3.1
608
@item msys-make 3.81-2 (note: not mingw32-make)
609
@item w32api 3.13
610
@item mingw-runtime 3.15
611
@end itemize
612

    
613
You will also need to pass @code{-fno-common} to the compiler to work around
614
a GCC bug (see @url{http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37216}).
615

    
616
Within the MSYS shell, configure and make with:
617

    
618
@example
619
./configure --enable-memalign-hack --extra-cflags=-fno-common
620
make
621
make install
622
@end example
623

    
624
This will install @file{ffmpeg.exe} along with many other development files
625
to @file{/usr/local}. You may specify another install path using the
626
@code{--prefix} option in @file{configure}.
627

    
628
Notes:
629

    
630
@itemize
631

    
632
@item In order to compile vhooks, you must have a POSIX-compliant libdl in
633
your MinGW system. Get dlfcn-win32 from
634
@url{http://code.google.com/p/dlfcn-win32}.
635

    
636
@item In order to compile FFplay, you must have the MinGW development library
637
of SDL. Get it from @url{http://www.libsdl.org}.
638
Edit the @file{bin/sdl-config} script so that it points to the correct prefix
639
where SDL was installed. Verify that @file{sdl-config} can be launched from
640
the MSYS command line.
641

    
642
@item By using @code{./configure --enable-shared} when configuring FFmpeg,
643
you can build libavutil, libavcodec and libavformat as DLLs.
644

    
645
@end itemize
646

    
647
@subsection Microsoft Visual C++ compatibility
648

    
649
As stated in the FAQ, FFmpeg will not compile under MSVC++. However, if you
650
want to use the libav* libraries in your own applications, you can still
651
compile those applications using MSVC++. But the libav* libraries you link
652
to @emph{must} be built with MinGW. However, you will not be able to debug
653
inside the libav* libraries, since MSVC++ does not recognize the debug
654
symbols generated by GCC.
655
We strongly recommend you to move over from MSVC++ to MinGW tools.
656

    
657
This description of how to use the FFmpeg libraries with MSVC++ is based on
658
Microsoft Visual C++ 2005 Express Edition. If you have a different version,
659
you might have to modify the procedures slightly.
660

    
661
@subsubsection Using static libraries
662

    
663
Assuming you have just built and installed FFmpeg in @file{/usr/local}.
664

    
665
@enumerate
666

    
667
@item Create a new console application ("File / New / Project") and then
668
select "Win32 Console Application". On the appropriate page of the
669
Application Wizard, uncheck the "Precompiled headers" option.
670

    
671
@item Write the source code for your application, or, for testing, just
672
copy the code from an existing sample application into the source file
673
that MSVC++ has already created for you. For example, you can copy
674
@file{output_example.c} from the FFmpeg distribution.
675

    
676
@item Open the "Project / Properties" dialog box. In the "Configuration"
677
combo box, select "All Configurations" so that the changes you make will
678
affect both debug and release builds. In the tree view on the left hand
679
side, select "C/C++ / General", then edit the "Additional Include
680
Directories" setting to contain the path where the FFmpeg includes were
681
installed (i.e. @file{c:\msys\1.0\local\include}).
682
Do not add MinGW's include directory here, or the include files will
683
conflict with MSVC's.
684

    
685
@item Still in the "Project / Properties" dialog box, select
686
"Linker / General" from the tree view and edit the
687
"Additional Library Directories" setting to contain the @file{lib}
688
directory where FFmpeg was installed (i.e. @file{c:\msys\1.0\local\lib}),
689
the directory where MinGW libs are installed (i.e. @file{c:\mingw\lib}),
690
and the directory where MinGW's GCC libs are installed
691
(i.e. @file{C:\mingw\lib\gcc\mingw32\4.2.1-sjlj}). Then select
692
"Linker / Input" from the tree view, and add the files @file{libavformat.a},
693
@file{libavcodec.a}, @file{libavutil.a}, @file{libmingwex.a},
694
@file{libgcc.a}, and any other libraries you used (i.e. @file{libz.a})
695
to the end of "Additional Dependencies".
696

    
697
@item Now, select "C/C++ / Code Generation" from the tree view. Select
698
"Debug" in the "Configuration" combo box. Make sure that "Runtime
699
Library" is set to "Multi-threaded Debug DLL". Then, select "Release" in
700
the "Configuration" combo box and make sure that "Runtime Library" is
701
set to "Multi-threaded DLL".
702

    
703
@item Click "OK" to close the "Project / Properties" dialog box.
704

    
705
@item MSVC++ lacks some C99 header files that are fundamental for FFmpeg.
706
Get msinttypes from @url{http://code.google.com/p/msinttypes/downloads/list}
707
and install it in MSVC++'s include directory
708
(i.e. @file{C:\Program Files\Microsoft Visual Studio 8\VC\include}).
709

    
710
@item MSVC++ also does not understand the @code{inline} keyword used by
711
FFmpeg, so you must add this line before @code{#include}ing libav*:
712
@example
713
#define inline _inline
714
@end example
715

    
716
@item Build your application, everything should work.
717

    
718
@end enumerate
719

    
720
@subsubsection Using shared libraries
721

    
722
This is how to create DLL and LIB files that are compatible with MSVC++:
723

    
724
@enumerate
725

    
726
@item Add a call to @file{vcvars32.bat} (which sets up the environment
727
variables for the Visual C++ tools) as the first line of @file{msys.bat}.
728
The standard location for @file{vcvars32.bat} is
729
@file{C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat},
730
and the standard location for @file{msys.bat} is @file{C:\msys\1.0\msys.bat}.
731
If this corresponds to your setup, add the following line as the first line
732
of @file{msys.bat}:
733

    
734
@example
735
call "C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat"
736
@end example
737

    
738
Alternatively, you may start the @file{Visual Studio 2005 Command Prompt},
739
and run @file{c:\msys\1.0\msys.bat} from there.
740

    
741
@item Within the MSYS shell, run @code{lib.exe}. If you get a help message
742
from @file{Microsoft (R) Library Manager}, this means your environment
743
variables are set up correctly, the @file{Microsoft (R) Library Manager}
744
is on the path and will be used by FFmpeg to create
745
MSVC++-compatible import libraries.
746

    
747
@item Build FFmpeg with
748

    
749
@example
750
./configure --enable-shared --enable-memalign-hack
751
make
752
make install
753
@end example
754

    
755
Your install path (@file{/usr/local/} by default) should now have the
756
necessary DLL and LIB files under the @file{bin} directory.
757

    
758
@end enumerate
759

    
760
To use those files with MSVC++, do the same as you would do with
761
the static libraries, as described above. But in Step 4,
762
you should only need to add the directory where the LIB files are installed
763
(i.e. @file{c:\msys\usr\local\bin}). This is not a typo, the LIB files are
764
installed in the @file{bin} directory. And instead of adding @file{libxx.a}
765
files, you should add @file{avcodec.lib}, @file{avformat.lib}, and
766
@file{avutil.lib}. There should be no need for @file{libmingwex.a},
767
@file{libgcc.a}, and @file{wsock32.lib}, nor any other external library
768
statically linked into the DLLs. The @file{bin} directory contains a bunch
769
of DLL files, but the ones that are actually used to run your application
770
are the ones with a major version number in their filenames
771
(i.e. @file{avcodec-51.dll}).
772

    
773
@subsection Cross compilation for Windows with Linux
774

    
775
You must use the MinGW cross compilation tools available at
776
@url{http://www.mingw.org/}.
777

    
778
Then configure FFmpeg with the following options:
779
@example
780
./configure --target-os=mingw32 --cross-prefix=i386-mingw32msvc-
781
@end example
782
(you can change the cross-prefix according to the prefix chosen for the
783
MinGW tools).
784

    
785
Then you can easily test FFmpeg with Wine
786
(@url{http://www.winehq.com/}).
787

    
788
@subsection Compilation under Cygwin
789

    
790
The main issue with the 1.5.x Cygwin versions is that newlib, its C library,
791
does not contain llrint().  You need to upgrade to the unstable 1.7.x versions,
792
or leverage the implementation in MinGW (as explained below).
793

    
794
Just install your Cygwin with all the "Base" packages, plus the
795
following "Devel" ones:
796
@example
797
binutils, gcc-core, make, subversion, mingw-runtime, diffutils
798
@end example
799

    
800
The experimental gcc4 package is still buggy, hence please
801
use the official gcc 3.4.4 or a 4.2.x compiled from source by yourself.
802

    
803
Install the current binutils-20080624-2 as they work fine (the old
804
binutils-20060709-1 proved buggy on shared builds).
805

    
806
Then create a small library that just contains llrint():
807

    
808
@example
809
ar x /usr/lib/mingw/libmingwex.a llrint.o
810
ar cq /usr/local/lib/libllrint.a llrint.o
811
@end example
812

    
813
Then run
814

    
815
@example
816
./configure --enable-static --disable-shared  --extra-ldflags='-L /usr/local/lib' --extra-libs='-l llrint'
817
@end example
818

    
819
to make a static build or
820

    
821
@example
822
./configure --enable-shared --disable-static  --extra-ldflags='-L /usr/local/lib' --extra-libs='-l llrint'
823
@end example
824

    
825
to build shared libraries.
826

    
827
If you want to build FFmpeg with additional libraries, download Cygwin
828
"Devel" packages for Ogg and Vorbis from any Cygwin packages repository:
829
@example
830
libogg-devel, libvorbis-devel
831
@end example
832

    
833
These library packages are only available from Cygwin Ports
834
(@url{http://sourceware.org/cygwinports/}) :
835

    
836
@example
837
yasm, libSDL-devel, libdirac-devel, libfaac-devel, libfaad-devel, libgsm-devel,
838
libmp3lame-devel, libschroedinger1.0-devel, speex-devel, libtheora-devel,
839
libxvidcore-devel
840
@end example
841

    
842
The recommendation for libnut and x264 is to build them from source by
843
yourself, as they evolve too quickly for Cygwin Ports to be up to date.
844

    
845
Cygwin 1.7.x has IPv6 support. You can add IPv6 to Cygwin 1.5.x by means
846
of the @code{libgetaddrinfo-devel} package, available at Cygwin Ports.
847

    
848
@subsection Crosscompilation for Windows under Cygwin
849

    
850
With Cygwin you can create Windows binaries that do not need the cygwin1.dll.
851

    
852
Just install your Cygwin as explained before, plus these additional
853
"Devel" packages:
854
@example
855
gcc-mingw-core, mingw-runtime, mingw-zlib
856
@end example
857

    
858
and add some special flags to your configure invocation.
859

    
860
For a static build run
861
@example
862
./configure --target-os=mingw32 --enable-memalign-hack --enable-static --disable-shared --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
863
@end example
864

    
865
and for a build with shared libraries
866
@example
867
./configure --target-os=mingw32 --enable-memalign-hack --enable-shared --disable-static --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
868
@end example
869

    
870
@section BeOS
871

    
872
BeOS support is broken in mysterious ways.
873

    
874
@section OS/2
875

    
876
For information about compiling FFmpeg on OS/2 see
877
@url{http://www.edm2.com/index.php/FFmpeg}.
878

    
879
@chapter Developers Guide
880

    
881
@section API
882
@itemize @bullet
883
@item libavcodec is the library containing the codecs (both encoding and
884
decoding). Look at @file{libavcodec/apiexample.c} to see how to use it.
885

    
886
@item libavformat is the library containing the file format handling (mux and
887
demux code for several formats). Look at @file{ffplay.c} to use it in a
888
player. See @file{output_example.c} to use it to generate audio or video
889
streams.
890

    
891
@end itemize
892

    
893
@section Integrating libavcodec or libavformat in your program
894

    
895
You can integrate all the source code of the libraries to link them
896
statically to avoid any version problem. All you need is to provide a
897
'config.mak' and a 'config.h' in the parent directory. See the defines
898
generated by ./configure to understand what is needed.
899

    
900
You can use libavcodec or libavformat in your commercial program, but
901
@emph{any patch you make must be published}. The best way to proceed is
902
to send your patches to the FFmpeg mailing list.
903

    
904
@node Coding Rules
905
@section Coding Rules
906

    
907
FFmpeg is programmed in the ISO C90 language with a few additional
908
features from ISO C99, namely:
909
@itemize @bullet
910
@item
911
the @samp{inline} keyword;
912
@item
913
@samp{//} comments;
914
@item
915
designated struct initializers (@samp{struct s x = @{ .i = 17 @};})
916
@item
917
compound literals (@samp{x = (struct s) @{ 17, 23 @};})
918
@end itemize
919

    
920
These features are supported by all compilers we care about, so we will not
921
accept patches to remove their use unless they absolutely do not impair
922
clarity and performance.
923

    
924
All code must compile with GCC 2.95 and GCC 3.3. Currently, FFmpeg also
925
compiles with several other compilers, such as the Compaq ccc compiler
926
or Sun Studio 9, and we would like to keep it that way unless it would
927
be exceedingly involved. To ensure compatibility, please do not use any
928
additional C99 features or GCC extensions. Especially watch out for:
929
@itemize @bullet
930
@item
931
mixing statements and declarations;
932
@item
933
@samp{long long} (use @samp{int64_t} instead);
934
@item
935
@samp{__attribute__} not protected by @samp{#ifdef __GNUC__} or similar;
936
@item
937
GCC statement expressions (@samp{(x = (@{ int y = 4; y; @})}).
938
@end itemize
939

    
940
Indent size is 4.
941
The presentation is the one specified by 'indent -i4 -kr -nut'.
942
The TAB character is forbidden outside of Makefiles as is any
943
form of trailing whitespace. Commits containing either will be
944
rejected by the Subversion repository.
945

    
946
The main priority in FFmpeg is simplicity and small code size in order to
947
minimize the bug count.
948

    
949
Comments: Use the JavaDoc/Doxygen
950
format (see examples below) so that code documentation
951
can be generated automatically. All nontrivial functions should have a comment
952
above them explaining what the function does, even if it is just one sentence.
953
All structures and their member variables should be documented, too.
954
@example
955
/**
956
 * @@file mpeg.c
957
 * MPEG codec.
958
 * @@author ...
959
 */
960

    
961
/**
962
 * Summary sentence.
963
 * more text ...
964
 * ...
965
 */
966
typedef struct Foobar@{
967
    int var1; /**< var1 description */
968
    int var2; ///< var2 description
969
    /** var3 description */
970
    int var3;
971
@} Foobar;
972

    
973
/**
974
 * Summary sentence.
975
 * more text ...
976
 * ...
977
 * @@param my_parameter description of my_parameter
978
 * @@return return value description
979
 */
980
int myfunc(int my_parameter)
981
...
982
@end example
983

    
984
fprintf and printf are forbidden in libavformat and libavcodec,
985
please use av_log() instead.
986

    
987
Casts should be used only when necessary. Unneeded parentheses
988
should also be avoided if they don't make the code easier to understand.
989

    
990
@section Development Policy
991

    
992
@enumerate
993
@item
994
   Contributions should be licensed under the LGPL 2.1, including an
995
   "or any later version" clause, or the MIT license.  GPL 2 including
996
   an "or any later version" clause is also acceptable, but LGPL is
997
   preferred.
998
@item
999
   You must not commit code which breaks FFmpeg! (Meaning unfinished but
1000
   enabled code which breaks compilation or compiles but does not work or
1001
   breaks the regression tests)
1002
   You can commit unfinished stuff (for testing etc), but it must be disabled
1003
   (#ifdef etc) by default so it does not interfere with other developers'
1004
   work.
1005
@item
1006
   You do not have to over-test things. If it works for you, and you think it
1007
   should work for others, then commit. If your code has problems
1008
   (portability, triggers compiler bugs, unusual environment etc) they will be
1009
   reported and eventually fixed.
1010
@item
1011
   Do not commit unrelated changes together, split them into self-contained
1012
   pieces. Also do not forget that if part B depends on part A, but A does not
1013
   depend on B, then A can and should be committed first and separate from B.
1014
   Keeping changes well split into self-contained parts makes reviewing and
1015
   understanding them on the commit log mailing list easier. This also helps
1016
   in case of debugging later on.
1017
   Also if you have doubts about splitting or not splitting, do not hesitate to
1018
   ask/discuss it on the developer mailing list.
1019
@item
1020
   Do not change behavior of the program (renaming options etc) without
1021
   first discussing it on the ffmpeg-devel mailing list. Do not remove
1022
   functionality from the code. Just improve!
1023

    
1024
   Note: Redundant code can be removed.
1025
@item
1026
   Do not commit changes to the build system (Makefiles, configure script)
1027
   which change behavior, defaults etc, without asking first. The same
1028
   applies to compiler warning fixes, trivial looking fixes and to code
1029
   maintained by other developers. We usually have a reason for doing things
1030
   the way we do. Send your changes as patches to the ffmpeg-devel mailing
1031
   list, and if the code maintainers say OK, you may commit. This does not
1032
   apply to files you wrote and/or maintain.
1033
@item
1034
   We refuse source indentation and other cosmetic changes if they are mixed
1035
   with functional changes, such commits will be rejected and removed. Every
1036
   developer has his own indentation style, you should not change it. Of course
1037
   if you (re)write something, you can use your own style, even though we would
1038
   prefer if the indentation throughout FFmpeg was consistent (Many projects
1039
   force a given indentation style - we do not.). If you really need to make
1040
   indentation changes (try to avoid this), separate them strictly from real
1041
   changes.
1042

    
1043
   NOTE: If you had to put if()@{ .. @} over a large (> 5 lines) chunk of code,
1044
   then either do NOT change the indentation of the inner part within (do not
1045
   move it to the right)! or do so in a separate commit
1046
@item
1047
   Always fill out the commit log message. Describe in a few lines what you
1048
   changed and why. You can refer to mailing list postings if you fix a
1049
   particular bug. Comments such as "fixed!" or "Changed it." are unacceptable.
1050
@item
1051
   If you apply a patch by someone else, include the name and email address in
1052
   the log message. Since the ffmpeg-cvslog mailing list is publicly
1053
   archived you should add some SPAM protection to the email address. Send an
1054
   answer to ffmpeg-devel (or wherever you got the patch from) saying that
1055
   you applied the patch.
1056
@item
1057
   When applying patches that have been discussed (at length) on the mailing
1058
   list, reference the thread in the log message.
1059
@item
1060
    Do NOT commit to code actively maintained by others without permission.
1061
    Send a patch to ffmpeg-devel instead. If no one answers within a reasonable
1062
    timeframe (12h for build failures and security fixes, 3 days small changes,
1063
    1 week for big patches) then commit your patch if you think it is OK.
1064
    Also note, the maintainer can simply ask for more time to review!
1065
@item
1066
    Subscribe to the ffmpeg-cvslog mailing list. The diffs of all commits
1067
    are sent there and reviewed by all the other developers. Bugs and possible
1068
    improvements or general questions regarding commits are discussed there. We
1069
    expect you to react if problems with your code are uncovered.
1070
@item
1071
    Update the documentation if you change behavior or add features. If you are
1072
    unsure how best to do this, send a patch to ffmpeg-devel, the documentation
1073
    maintainer(s) will review and commit your stuff.
1074
@item
1075
    Try to keep important discussions and requests (also) on the public
1076
    developer mailing list, so that all developers can benefit from them.
1077
@item
1078
    Never write to unallocated memory, never write over the end of arrays,
1079
    always check values read from some untrusted source before using them
1080
    as array index or other risky things.
1081
@item
1082
    Remember to check if you need to bump versions for the specific libav
1083
    parts (libavutil, libavcodec, libavformat) you are changing. You need
1084
    to change the version integer.
1085
    Incrementing the first component means no backward compatibility to
1086
    previous versions (e.g. removal of a function from the public API).
1087
    Incrementing the second component means backward compatible change
1088
    (e.g. addition of a function to the public API or extension of an
1089
    existing data structure).
1090
    Incrementing the third component means a noteworthy binary compatible
1091
    change (e.g. encoder bug fix that matters for the decoder).
1092
@item
1093
    Compiler warnings indicate potential bugs or code with bad style. If a type of
1094
    warning always points to correct and clean code, that warning should
1095
    be disabled, not the code changed.
1096
    Thus the remaining warnings can either be bugs or correct code.
1097
    If it is a bug, the bug has to be fixed. If it is not, the code should
1098
    be changed to not generate a warning unless that causes a slowdown
1099
    or obfuscates the code.
1100
@item
1101
    If you add a new file, give it a proper license header. Do not copy and
1102
    paste it from a random place, use an existing file as template.
1103
@end enumerate
1104

    
1105
We think our rules are not too hard. If you have comments, contact us.
1106

    
1107
Note, these rules are mostly borrowed from the MPlayer project.
1108

    
1109
@section Submitting patches
1110

    
1111
First, (@pxref{Coding Rules}) above if you did not yet.
1112

    
1113
When you submit your patch, try to send a unified diff (diff '-up'
1114
option). We cannot read other diffs :-)
1115

    
1116
Also please do not submit a patch which contains several unrelated changes.
1117
Split it into separate, self-contained pieces. This does not mean splitting
1118
file by file. Instead, make the patch as small as possible while still
1119
keeping it as a logical unit that contains an individual change, even
1120
if it spans multiple files. This makes reviewing your patches much easier
1121
for us and greatly increases your chances of getting your patch applied.
1122

    
1123
Run the regression tests before submitting a patch so that you can
1124
verify that there are no big problems.
1125

    
1126
Patches should be posted as base64 encoded attachments (or any other
1127
encoding which ensures that the patch will not be trashed during
1128
transmission) to the ffmpeg-devel mailing list, see
1129
@url{http://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel}
1130

    
1131
It also helps quite a bit if you tell us what the patch does (for example
1132
'replaces lrint by lrintf'), and why (for example '*BSD isn't C99 compliant
1133
and has no lrint()')
1134

    
1135
Also please if you send several patches, send each patch as a separate mail,
1136
do not attach several unrelated patches to the same mail.
1137

    
1138
@section New codecs or formats checklist
1139

    
1140
@enumerate
1141
@item
1142
    Did you use av_cold for codec initialization and close functions?
1143
@item
1144
    Did you add a long_name under NULL_IF_CONFIG_SMALL to the AVCodec or
1145
    AVInputFormat/AVOutputFormat struct?
1146
@item
1147
    Did you bump the minor version number in @file{avcodec.h} or
1148
    @file{avformat.h}?
1149
@item
1150
    Did you register it in @file{allcodecs.c} or @file{allformats.c}?
1151
@item
1152
    Did you add the CodecID to @file{avcodec.h}?
1153
@item
1154
    If it has a fourcc, did you add it to @file{libavformat/riff.c},
1155
    even if it is only a decoder?
1156
@item
1157
    Did you add a rule to compile the appropriate files in the Makefile?
1158
    Remember to do this even if you're just adding a format to a file that is
1159
    already being compiled by some other rule, like a raw demuxer.
1160
@item
1161
    Did you add an entry to the table of supported formats or codecs in the
1162
    documentation?
1163
@item
1164
    Did you add an entry in the Changelog?
1165
@item
1166
    If it depends on a parser or a library, did you add that dependency in
1167
    configure?
1168
@item
1169
    Did you "svn add" the appropriate files before commiting?
1170
@end enumerate
1171

    
1172
@section patch submission checklist
1173

    
1174
@enumerate
1175
@item
1176
    Do the regression tests pass with the patch applied?
1177
@item
1178
    Does @code{make checkheaders} pass with the patch applied?
1179
@item
1180
    Is the patch a unified diff?
1181
@item
1182
    Is the patch against latest FFmpeg SVN?
1183
@item
1184
    Are you subscribed to ffmpeg-dev?
1185
    (the list is subscribers only due to spam)
1186
@item
1187
    Have you checked that the changes are minimal, so that the same cannot be
1188
    achieved with a smaller patch and/or simpler final code?
1189
@item
1190
    If the change is to speed critical code, did you benchmark it?
1191
@item
1192
    If you did any benchmarks, did you provide them in the mail?
1193
@item
1194
    Have you checked that the patch does not introduce buffer overflows or
1195
    other security issues?
1196
@item
1197
    Did you test your decoder or demuxer against damaged data? If no, see
1198
    tools/trasher and the noise bitstream filter. Your decoder or demuxer
1199
    should not crash or end in a (near) infinite loop when fed damaged data.
1200
@item
1201
    Is the patch created from the root of the source tree, so it can be
1202
    applied with @code{patch -p0}?
1203
@item
1204
    Does the patch not mix functional and cosmetic changes?
1205
@item
1206
    Did you add tabs or trailing whitespace to the code? Both are forbidden.
1207
@item
1208
    Is the patch attached to the email you send?
1209
@item
1210
    Is the mime type of the patch correct? It should be text/x-diff or
1211
    text/x-patch or at least text/plain and not application/octet-stream.
1212
@item
1213
    If the patch fixes a bug, did you provide a verbose analysis of the bug?
1214
@item
1215
    If the patch fixes a bug, did you provide enough information, including
1216
    a sample, so the bug can be reproduced and the fix can be verified?
1217
    Note please do not attach samples >100k to mails but rather provide a
1218
    URL, you can upload to ftp://upload.ffmpeg.org
1219
@item
1220
    Did you provide a verbose summary about what the patch does change?
1221
@item
1222
    Did you provide a verbose explanation why it changes things like it does?
1223
@item
1224
    Did you provide a verbose summary of the user visible advantages and
1225
    disadvantages if the patch is applied?
1226
@item
1227
    Did you provide an example so we can verify the new feature added by the
1228
    patch easily?
1229
@item
1230
    If you added a new file, did you insert a license header? It should be
1231
    taken from FFmpeg, not randomly copied and pasted from somewhere else.
1232
@item
1233
    You should maintain alphabetical order in alphabetically ordered lists as
1234
    long as doing so does not break API/ABI compatibility.
1235
@item
1236
    Lines with similar content should be aligned vertically when doing so
1237
    improves readability.
1238
@item
1239
    Did you provide a suggestion for a clear commit log message?
1240
@end enumerate
1241

    
1242
@section Patch review process
1243

    
1244
All patches posted to ffmpeg-devel will be reviewed, unless they contain a
1245
clear note that the patch is not for SVN.
1246
Reviews and comments will be posted as replies to the patch on the
1247
mailing list. The patch submitter then has to take care of every comment,
1248
that can be by resubmitting a changed patch or by discussion. Resubmitted
1249
patches will themselves be reviewed like any other patch. If at some point
1250
a patch passes review with no comments then it is approved, that can for
1251
simple and small patches happen immediately while large patches will generally
1252
have to be changed and reviewed many times before they are approved.
1253
After a patch is approved it will be committed to the repository.
1254

    
1255
We will review all submitted patches, but sometimes we are quite busy so
1256
especially for large patches this can take several weeks.
1257

    
1258
When resubmitting patches, please do not make any significant changes
1259
not related to the comments received during review. Such patches will
1260
be rejected. Instead, submit  significant changes or new features as
1261
separate patches.
1262

    
1263
@section Regression tests
1264

    
1265
Before submitting a patch (or committing to the repository), you should at least
1266
test that you did not break anything.
1267

    
1268
The regression tests build a synthetic video stream and a synthetic
1269
audio stream. These are then encoded and decoded with all codecs or
1270
formats. The CRC (or MD5) of each generated file is recorded in a
1271
result file. A 'diff' is launched to compare the reference results and
1272
the result file.
1273

    
1274
The regression tests then go on to test the FFserver code with a
1275
limited set of streams. It is important that this step runs correctly
1276
as well.
1277

    
1278
Run 'make test' to test all the codecs and formats.
1279

    
1280
Run 'make fulltest' to test all the codecs, formats and FFserver.
1281

    
1282
[Of course, some patches may change the results of the regression tests. In
1283
this case, the reference results of the regression tests shall be modified
1284
accordingly].
1285

    
1286
@bye