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953 lines
40 KiB
\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, WB and NB. FFmpeg can make use of the |
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AMR WB (floating-point mode) and the AMR NB (floating-point mode) reference |
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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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@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 Supported File Format @tab Encoding @tab Decoding @tab Comments |
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@item MPEG audio @tab X @tab X |
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@item MPEG-1 systems @tab X @tab X |
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@tab muxed audio and video |
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@item MPEG-2 PS @tab X @tab X |
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@tab also known as @code{VOB} file |
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@item MPEG-2 TS @tab @tab X |
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@tab also known as DVB Transport Stream |
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@item ASF@tab X @tab X |
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@item AVI@tab X @tab X |
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@item WAV@tab X @tab X |
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@item Macromedia Flash@tab X @tab X |
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@tab Only embedded audio is decoded. |
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@item FLV @tab X @tab X |
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@tab Macromedia Flash video files |
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@item Real Audio and Video @tab X @tab X |
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@item Raw AC3 @tab X @tab X |
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@item Raw MJPEG @tab X @tab X |
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@item Raw MPEG video @tab X @tab X |
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@item Raw PCM8/16 bits, mulaw/Alaw@tab X @tab X |
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@item Raw CRI ADX audio @tab X @tab X |
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@item Raw Shorten audio @tab @tab X |
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@item SUN AU format @tab X @tab X |
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@item NUT @tab X @tab X @tab NUT Open Container Format |
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@item QuickTime @tab X @tab X |
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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 Raw MPEG4 video @tab X @tab X |
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@item DV @tab X @tab X |
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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 Playstation STR @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 Interplay MVE @tab @tab X |
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@tab Format used in various Interplay computer games. |
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@item WC3 Movie @tab @tab X |
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@tab Multimedia format used in Origin's Wing Commander III computer game. |
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@item Sega FILM/CPK @tab @tab X |
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@tab Used in many Sega Saturn console games. |
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@item Westwood Studios VQA/AUD @tab @tab X |
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@tab Multimedia formats used in Westwood Studios games. |
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@item Id Cinematic (.cin) @tab @tab X |
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@tab Used in Quake II. |
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@item FLIC format @tab @tab X |
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@tab .fli/.flc files |
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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 Sierra Online @tab @tab X |
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@tab .sol files used in Sierra Online games. |
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@item Matroska @tab X @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 Nullsoft Video (NSV) format @tab @tab X |
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@item ADTS AAC audio @tab X @tab X |
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@item Creative VOC @tab X @tab X @tab Created for the Sound Blaster Pro. |
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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 AVS @tab @tab X |
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@tab Multimedia format used by the Creature Shock game. |
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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 GXF @tab X @tab X |
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@tab General eXchange Format SMPTE 360M, used by Thomson Grass Valley playout servers. |
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@item CIN @tab @tab X |
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@tab Multimedia format used by Delphine Software games. |
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@item MXF @tab @tab X |
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@tab Material eXchange Format SMPTE 377M, used by D-Cinema, broadcast industry. |
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@item SEQ @tab @tab X |
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@tab Tiertex .seq files used in the DOS CDROM version of the game Flashback. |
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@item DXA @tab @tab X |
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@tab This format is used in non-Windows version of Feeble Files game and |
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different game cutscenes repacked for use with ScummVM. |
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@item THP @tab @tab X |
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@tab Used on the Nintendo GameCube. |
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@item C93 @tab @tab X |
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@tab Used in the game Cyberia from Interplay. |
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@item Bethsoft VID @tab @tab X |
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@tab Used in some games from Bethesda Softworks. |
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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 Monkey's Audio @tab @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 Supported Image Format @tab Encoding @tab Decoding @tab Comments |
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@item PGM, PPM @tab X @tab X |
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@item PAM @tab X @tab X @tab PAM is a PNM extension with alpha support. |
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@item PGMYUV @tab X @tab X @tab PGM with U and V components in YUV 4:2:0 |
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@item JPEG @tab X @tab X @tab Progressive JPEG is not supported. |
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@item .Y.U.V @tab X @tab X @tab one raw file per component |
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@item animated GIF @tab X @tab X @tab Only uncompressed GIFs are generated. |
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@item PNG @tab X @tab X @tab 2 bit and 4 bit/pixel not supported yet. |
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@item Targa @tab @tab X @tab Targa (.TGA) image format. |
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@item TIFF @tab X @tab X @tab YUV, JPEG and some extension is not supported yet. |
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@item SGI @tab X @tab X @tab SGI RGB image format |
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@item PTX @tab @tab X @tab V.Flash PTX format |
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@end multitable |
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@code{X} means that encoding (resp. decoding) is supported. |
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@section Video Codecs |
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@multitable @columnfractions .4 .1 .1 .4 |
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@item Supported Codec @tab Encoding @tab Decoding @tab Comments |
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@item MPEG-1 video @tab X @tab X |
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@item MPEG-2 video @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 WMV7 @tab X @tab X |
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@item WMV8 @tab X @tab X @tab not completely working |
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@item WMV9 @tab @tab X @tab not completely working |
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@item VC1 @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 @tab also known as RealVideo 1.0 |
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@item H.264 @tab @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 MJPEG @tab X @tab X |
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@item lossless MJPEG @tab X @tab X |
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@item JPEG-LS @tab X @tab X @tab fourcc: MJLS, lossless and near-lossless is supported |
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@item Apple MJPEG-B @tab @tab X |
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@item Sunplus MJPEG @tab @tab X @tab fourcc: SP5X |
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@item DV @tab X @tab X |
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@item HuffYUV @tab X @tab X |
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@item FFmpeg Video 1 @tab X @tab X @tab experimental lossless codec (fourcc: FFV1) |
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@item FFmpeg Snow @tab X @tab X @tab experimental wavelet codec (fourcc: SNOW) |
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@item Asus v1 @tab X @tab X @tab fourcc: ASV1 |
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@item Asus v2 @tab X @tab X @tab fourcc: ASV2 |
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@item Creative YUV @tab @tab X @tab fourcc: CYUV |
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@item Sorenson Video 1 @tab X @tab X @tab fourcc: SVQ1 |
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@item Sorenson Video 3 @tab @tab X @tab fourcc: SVQ3 |
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@item On2 VP3 @tab @tab X @tab still experimental |
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@item On2 VP5 @tab @tab X @tab fourcc: VP50 |
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@item On2 VP6 @tab @tab X @tab fourcc: VP60,VP61,VP62 |
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@item Theora @tab X @tab X @tab still experimental |
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@item Intel Indeo 3 @tab @tab X |
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@item FLV @tab X @tab X @tab Sorenson H.263 used in Flash |
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@item Flash Screen Video @tab X @tab X @tab fourcc: FSV1 |
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@item ATI VCR1 @tab @tab X @tab fourcc: VCR1 |
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@item ATI VCR2 @tab @tab X @tab fourcc: VCR2 |
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@item Cirrus Logic AccuPak @tab @tab X @tab fourcc: CLJR |
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@item 4X Video @tab @tab X @tab Used in certain computer games. |
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@item Sony Playstation MDEC @tab @tab X |
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@item Id RoQ @tab X @tab X @tab Used in Quake III, Jedi Knight 2, other computer games. |
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@item Xan/WC3 @tab @tab X @tab Used in Wing Commander III .MVE files. |
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@item Interplay Video @tab @tab X @tab Used in Interplay .MVE files. |
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@item Apple Animation @tab X @tab X @tab fourcc: 'rle ' |
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@item Apple Graphics @tab @tab X @tab fourcc: 'smc ' |
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@item Apple Video @tab @tab X @tab fourcc: rpza |
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@item Apple QuickDraw @tab @tab X @tab fourcc: qdrw |
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@item Cinepak @tab @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 Westwood VQA @tab @tab X |
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@item Id Cinematic Video @tab @tab X @tab Used in Quake II. |
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@item Planar RGB @tab @tab X @tab fourcc: 8BPS |
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@item FLIC video @tab @tab X |
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@item Duck TrueMotion v1 @tab @tab X @tab fourcc: DUCK |
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@item Duck TrueMotion v2 @tab @tab X @tab fourcc: TM20 |
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@item VMD Video @tab @tab X @tab Used in Sierra VMD files. |
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@item MSZH @tab @tab X @tab Part of LCL |
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@item ZLIB @tab X @tab X @tab Part of LCL, encoder experimental |
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@item TechSmith Camtasia @tab @tab X @tab fourcc: TSCC |
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@item IBM Ultimotion @tab @tab X @tab fourcc: ULTI |
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@item Miro VideoXL @tab @tab X @tab fourcc: VIXL |
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@item QPEG @tab @tab X @tab fourccs: QPEG, Q1.0, Q1.1 |
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@item LOCO @tab @tab X @tab |
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@item Winnov WNV1 @tab @tab X @tab |
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@item Autodesk Animator Studio Codec @tab @tab X @tab fourcc: AASC |
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@item Fraps FPS1 @tab @tab X @tab |
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@item CamStudio @tab @tab X @tab fourcc: CSCD |
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@item American Laser Games Video @tab @tab X @tab Used in games like Mad Dog McCree |
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@item ZMBV @tab X @tab X @tab Encoder works only on PAL8 |
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@item AVS Video @tab @tab X @tab Video encoding used by the Creature Shock game. |
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@item Smacker Video @tab @tab X @tab Video encoding used in Smacker. |
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@item RTjpeg @tab @tab X @tab Video encoding used in NuppelVideo files. |
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@item KMVC @tab @tab X @tab Codec used in Worms games. |
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@item VMware Video @tab @tab X @tab Codec used in videos captured by VMware. |
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@item Cin Video @tab @tab X @tab Codec used in Delphine Software games. |
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@item Tiertex Seq Video @tab @tab X @tab Codec used in DOS CDROM FlashBack game. |
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@item DXA Video @tab @tab X @tab Codec originally used in Feeble Files game. |
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@item AVID DNxHD @tab X @tab X @tab aka SMPTE VC3 |
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@item C93 Video @tab @tab X @tab Codec used in Cyberia game. |
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@item THP @tab @tab X @tab Used on the Nintendo GameCube. |
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@item Bethsoft VID @tab @tab X @tab Used in some games from Bethesda Softworks. |
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@item Renderware TXD @tab @tab X @tab Texture dictionaries used by the Renderware Engine. |
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@item AMV @tab @tab X @tab Used in Chinese MP3 players. |
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@end multitable |
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@code{X} means that encoding (resp. decoding) is supported. |
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@section Audio Codecs |
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@multitable @columnfractions .4 .1 .1 .1 .7 |
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@item Supported Codec @tab Encoding @tab Decoding @tab Comments |
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@item MPEG audio layer 2 @tab IX @tab IX |
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@item MPEG audio layer 1/3 @tab IX @tab IX |
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@tab MP3 encoding is supported through the external library LAME. |
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@item AC3 @tab IX @tab IX |
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@tab liba52 is used internally for decoding. |
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@item Vorbis @tab X @tab X |
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@item WMA V1/V2 @tab X @tab X |
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@item AAC @tab X @tab X |
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@tab Supported through the external library libfaac/libfaad. |
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@item Microsoft ADPCM @tab X @tab X |
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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 MS IMA ADPCM @tab X @tab X |
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@item QT IMA ADPCM @tab @tab X |
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@item 4X IMA ADPCM @tab @tab X |
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@item G.726 ADPCM @tab X @tab X |
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@item Duck DK3 IMA ADPCM @tab @tab X |
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@tab Used in some Sega Saturn console games. |
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@item Duck DK4 IMA ADPCM @tab @tab X |
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@tab Used in some Sega Saturn console games. |
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@item Westwood Studios IMA ADPCM @tab @tab X |
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@tab Used in Westwood Studios games like Command and Conquer. |
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@item SMJPEG IMA ADPCM @tab @tab X |
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@tab Used in certain Loki game ports. |
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@item CD-ROM XA ADPCM @tab @tab X |
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@item CRI ADX ADPCM @tab X @tab X |
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@tab Used in Sega Dreamcast games. |
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@item Electronic Arts ADPCM @tab @tab X |
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@tab Used in various EA titles. |
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@item Creative ADPCM @tab @tab X |
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@tab 16 -> 4, 8 -> 4, 8 -> 3, 8 -> 2 |
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@item THP ADPCM @tab @tab X |
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@tab Used on the Nintendo GameCube. |
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@item RA144 @tab @tab X |
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@tab Real 14400 bit/s codec |
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@item RA288 @tab @tab X |
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@tab Real 28800 bit/s codec |
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@item RADnet @tab X @tab IX |
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@tab Real low bitrate AC3 codec, liba52 is used for decoding. |
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@item AMR-NB @tab X @tab X |
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@tab Supported through an external library. |
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@item AMR-WB @tab X @tab X |
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@tab Supported through an external library. |
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@item DV audio @tab @tab X |
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@item Id RoQ DPCM @tab X @tab X |
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@tab Used in Quake III, Jedi Knight 2, other computer games. |
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@item Interplay MVE DPCM @tab @tab X |
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@tab Used in various Interplay computer games. |
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@item Xan DPCM @tab @tab X |
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@tab Used in Origin's Wing Commander IV AVI files. |
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@item Sierra Online DPCM @tab @tab X |
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@tab Used in Sierra Online game audio files. |
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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 FLAC lossless audio @tab X @tab X |
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@item Shorten lossless audio @tab @tab X |
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@item Apple lossless audio @tab @tab X |
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@tab QuickTime fourcc 'alac' |
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@item FFmpeg Sonic @tab X @tab X |
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@tab experimental lossy/lossless codec |
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@item Qdesign QDM2 @tab @tab X |
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@tab there are still some distortions |
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@item Real COOK @tab @tab X |
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@tab All versions except 5.1 are supported |
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@item DSP Group TrueSpeech @tab @tab X |
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@item True Audio (TTA) @tab @tab X |
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@item Smacker Audio @tab @tab X |
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@item WavPack Audio @tab @tab X |
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@item Cin Audio @tab @tab X |
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@tab Codec used in Delphine Software games. |
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@item Intel Music Coder @tab @tab X |
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@item Musepack @tab @tab X |
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@tab Only SV7 is supported |
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@item DT$ Coherent Audio @tab @tab X |
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@item ATRAC 3 @tab @tab X |
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@item Monkey's Audio @tab @tab X @tab Only versions 3.97-3.99 are supported |
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@end multitable |
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@code{X} means that encoding (resp. decoding) is supported. |
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@code{I} means that an integer-only version is available, too (ensures high |
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performance on systems without hardware floating point support). |
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@chapter Platform Specific information |
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@section BSD |
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BSD make will not build FFmpeg, you need to install and use GNU Make |
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(@file{gmake}). |
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@section Windows |
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To get help and instructions for using FFmpeg under Windows, check out |
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the FFmpeg Windows Help Forum at |
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@url{http://arrozcru.no-ip.org/ffmpeg/}. |
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@subsection Native Windows compilation |
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@itemize |
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@item Install the current versions of MSYS and MinGW from |
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@url{http://www.mingw.org/}. You can find detailed installation |
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instructions in the download section and the FAQ. |
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NOTE: Use at least bash 3.1. Older versions are known to be failing on the |
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configure script. |
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@item If you want to test the FFplay, also download |
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the MinGW development library of SDL 1.2.x |
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(@file{SDL-devel-1.2.x-mingw32.tar.gz}) from |
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@url{http://www.libsdl.org}. Unpack it in a temporary directory, and |
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unpack the archive @file{i386-mingw32msvc.tar.gz} in the MinGW tool |
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directory. Edit the @file{sdl-config} script so that it gives the |
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correct SDL directory when invoked. |
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@item If you want to use vhooks, you must have a POSIX compliant libdl in your |
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MinGW system. Get dlfcn-win32 from @url{http://code.google.com/p/dlfcn-win32}. |
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@item Extract the current version of FFmpeg. |
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@item Start the MSYS shell (file @file{msys.bat}). |
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@item Change to the FFmpeg directory and follow |
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the instructions of how to compile FFmpeg (file |
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@file{INSTALL}). Usually, launching @file{./configure} and @file{make} |
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suffices. If you have problems using SDL, verify that |
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@file{sdl-config} can be launched from the MSYS command line. |
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@item You can install FFmpeg in @file{Program Files/FFmpeg} by typing |
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@file{make install}. Do not forget to copy @file{SDL.dll} to the place |
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you launch @file{ffplay} from. |
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@end itemize |
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Notes: |
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@itemize |
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@item The target @file{make wininstaller} can be used to create a |
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Nullsoft based Windows installer for FFmpeg and FFplay. @file{SDL.dll} |
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must be copied to the FFmpeg directory in order to build the |
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installer. |
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@item By using @code{./configure --enable-shared} when configuring FFmpeg, |
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you can build @file{avcodec.dll} and @file{avformat.dll}. With |
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@code{make install} you install the FFmpeg DLLs and the associated |
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headers in @file{Program Files/FFmpeg}. |
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@item Visual C++ compatibility: If you used @code{./configure --enable-shared} |
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when configuring FFmpeg, FFmpeg tries to use the Microsoft Visual |
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C++ @code{lib} tool to build @code{avcodec.lib} and |
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@code{avformat.lib}. With these libraries you can link your Visual C++ |
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code directly with the FFmpeg DLLs (see below). |
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@end itemize |
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@subsection Visual C++ compatibility |
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FFmpeg will not compile under Visual C++ -- and it has too many |
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dependencies on the GCC compiler to make a port viable. However, |
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if you want to use the FFmpeg libraries in your own applications, |
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you can still compile those applications using Visual C++. An |
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important restriction to this is that you have to use the |
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dynamically linked versions of the FFmpeg libraries (i.e. the |
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DLLs), and you have to make sure that Visual-C++-compatible |
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import libraries are created during the FFmpeg build process. |
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This description of how to use the FFmpeg libraries with Visual C++ is |
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based on Visual C++ 2005 Express Edition Beta 2. If you have a different |
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version, you might have to modify the procedures slightly. |
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Here are the step-by-step instructions for building the FFmpeg libraries |
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so they can be used with Visual C++: |
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@enumerate |
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@item Install Visual C++ (if you have not done so already). |
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@item Install MinGW and MSYS as described above. |
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@item Add a call to @file{vcvars32.bat} (which sets up the environment |
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variables for the Visual C++ tools) as the first line of |
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@file{msys.bat}. The standard location for @file{vcvars32.bat} is |
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@file{C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat}, |
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and the standard location for @file{msys.bat} is |
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@file{C:\msys\1.0\msys.bat}. If this corresponds to your setup, add the |
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following line as the first line of @file{msys.bat}: |
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@code{call "C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat"} |
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@item Start the MSYS shell (file @file{msys.bat}) and type @code{link.exe}. |
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If you get a help message with the command line options of @code{link.exe}, |
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this means your environment variables are set up correctly, the |
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Microsoft linker is on the path and will be used by FFmpeg to |
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create Visual-C++-compatible import libraries. |
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@item Extract the current version of FFmpeg and change to the FFmpeg directory. |
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@item Type the command |
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@code{./configure --enable-shared --disable-static --enable-memalign-hack} |
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to configure and, if that did not produce any errors, |
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type @code{make} to build FFmpeg. |
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@item The subdirectories @file{libavformat}, @file{libavcodec}, and |
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@file{libavutil} should now contain the files @file{avformat.dll}, |
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@file{avformat.lib}, @file{avcodec.dll}, @file{avcodec.lib}, |
|
@file{avutil.dll}, and @file{avutil.lib}, respectively. Copy the three |
|
DLLs to your System32 directory (typically @file{C:\Windows\System32}). |
|
|
|
@end enumerate |
|
|
|
And here is how to use these libraries with Visual C++: |
|
|
|
@enumerate |
|
|
|
@item Create a new console application ("File / New / Project") and then |
|
select "Win32 Console Application". On the appropriate page of the |
|
Application Wizard, uncheck the "Precompiled headers" option. |
|
|
|
@item Write the source code for your application, or, for testing, just |
|
copy the code from an existing sample application into the source file |
|
that Visual C++ has already created for you. (Note that your source |
|
filehas to have a @code{.cpp} extension; otherwise, Visual C++ will not |
|
compile the FFmpeg headers correctly because in C mode, it does not |
|
recognize the @code{inline} keyword.) For example, you can copy |
|
@file{output_example.c} from the FFmpeg distribution (but you will |
|
have to make minor modifications so the code will compile under |
|
C++, see below). |
|
|
|
@item Open the "Project / Properties" dialog box. In the "Configuration" |
|
combo box, select "All Configurations" so that the changes you make will |
|
affect both debug and release builds. In the tree view on the left hand |
|
side, select "C/C++ / General", then edit the "Additional Include |
|
Directories" setting to contain the complete paths to the |
|
@file{libavformat}, @file{libavcodec}, and @file{libavutil} |
|
subdirectories of your FFmpeg directory. Note that the directories have |
|
to be separated using semicolons. Now select "Linker / General" from the |
|
tree view and edit the "Additional Library Directories" setting to |
|
contain the same three directories. |
|
|
|
@item Still in the "Project / Properties" dialog box, select "Linker / Input" |
|
from the tree view, then add the files @file{avformat.lib}, |
|
@file{avcodec.lib}, and @file{avutil.lib} to the end of the "Additional |
|
Dependencies". Note that the names of the libraries have to be separated |
|
using spaces. |
|
|
|
@item Now, select "C/C++ / Code Generation" from the tree view. Select |
|
"Debug" in the "Configuration" combo box. Make sure that "Runtime |
|
Library" is set to "Multi-threaded Debug DLL". Then, select "Release" in |
|
the "Configuration" combo box and make sure that "Runtime Library" is |
|
set to "Multi-threaded DLL". |
|
|
|
@item Click "OK" to close the "Project / Properties" dialog box and build |
|
the application. Hopefully, it should compile and run cleanly. If you |
|
used @file{output_example.c} as your sample application, you will get a |
|
few compiler errors, but they are easy to fix. The first type of error |
|
occurs because Visual C++ does not allow an @code{int} to be converted to |
|
an @code{enum} without a cast. To solve the problem, insert the required |
|
casts (this error occurs once for a @code{CodecID} and once for a |
|
@code{CodecType}). The second type of error occurs because C++ requires |
|
the return value of @code{malloc} to be cast to the exact type of the |
|
pointer it is being assigned to. Visual C++ will complain that, for |
|
example, @code{(void *)} is being assigned to @code{(uint8_t *)} without |
|
an explicit cast. So insert an explicit cast in these places to silence |
|
the compiler. The third type of error occurs because the @code{snprintf} |
|
library function is called @code{_snprintf} under Visual C++. So just |
|
add an underscore to fix the problem. With these changes, |
|
@file{output_example.c} should compile under Visual C++, and the |
|
resulting executable should produce valid video files. |
|
|
|
@end enumerate |
|
|
|
@subsection Cross compilation for Windows with Linux |
|
|
|
You must use the MinGW cross compilation tools available at |
|
@url{http://www.mingw.org/}. |
|
|
|
Then configure FFmpeg with the following options: |
|
@example |
|
./configure --target-os=mingw32 --cross-prefix=i386-mingw32msvc- |
|
@end example |
|
(you can change the cross-prefix according to the prefix chosen for the |
|
MinGW tools). |
|
|
|
Then you can easily test FFmpeg with Wine |
|
(@url{http://www.winehq.com/}). |
|
|
|
@subsection Compilation under Cygwin |
|
|
|
Cygwin works very much like Unix. |
|
|
|
Just install your Cygwin with all the "Base" packages, plus the |
|
following "Devel" ones: |
|
@example |
|
binutils, gcc-core, make, subversion |
|
@end example |
|
|
|
Do not install binutils-20060709-1 (they are buggy on shared builds); |
|
use binutils-20050610-1 instead. |
|
|
|
Then run |
|
|
|
@example |
|
./configure --enable-static --disable-shared |
|
@end example |
|
|
|
to make a static build or |
|
|
|
@example |
|
./configure --enable-shared --disable-static |
|
@end example |
|
|
|
to build shared libraries. |
|
|
|
If you want to build FFmpeg with additional libraries, download Cygwin |
|
"Devel" packages for Ogg and Vorbis from any Cygwin packages repository |
|
and/or SDL, xvid, faac, faad2 packages from Cygwin Ports, |
|
(@url{http://cygwinports.dotsrc.org/}). |
|
|
|
@subsection Crosscompilation for Windows under Cygwin |
|
|
|
With Cygwin you can create Windows binaries that do not need the cygwin1.dll. |
|
|
|
Just install your Cygwin as explained before, plus these additional |
|
"Devel" packages: |
|
@example |
|
gcc-mingw-core, mingw-runtime, mingw-zlib |
|
@end example |
|
|
|
and add some special flags to your configure invocation. |
|
|
|
For a static build run |
|
@example |
|
./configure --target-os=mingw32 --enable-memalign-hack --enable-static --disable-shared --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin |
|
@end example |
|
|
|
and for a build with shared libraries |
|
@example |
|
./configure --target-os=mingw32 --enable-memalign-hack --enable-shared --disable-static --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin |
|
@end example |
|
|
|
@section BeOS |
|
|
|
BeOS support is broken in mysterious ways. |
|
|
|
@chapter Developers Guide |
|
|
|
@section API |
|
@itemize @bullet |
|
@item libavcodec is the library containing the codecs (both encoding and |
|
decoding). Look at @file{libavcodec/apiexample.c} to see how to use it. |
|
|
|
@item libavformat is the library containing the file format handling (mux and |
|
demux code for several formats). Look at @file{ffplay.c} to use it in a |
|
player. See @file{output_example.c} to use it to generate audio or video |
|
streams. |
|
|
|
@end itemize |
|
|
|
@section Integrating libavcodec or libavformat in your program |
|
|
|
You can integrate all the source code of the libraries to link them |
|
statically to avoid any version problem. All you need is to provide a |
|
'config.mak' and a 'config.h' in the parent directory. See the defines |
|
generated by ./configure to understand what is needed. |
|
|
|
You can use libavcodec or libavformat in your commercial program, but |
|
@emph{any patch you make must be published}. The best way to proceed is |
|
to send your patches to the FFmpeg mailing list. |
|
|
|
@node Coding Rules |
|
@section Coding Rules |
|
|
|
FFmpeg is programmed in the ISO C90 language with a few additional |
|
features from ISO C99, namely: |
|
@itemize @bullet |
|
@item |
|
the @samp{inline} keyword; |
|
@item |
|
@samp{//} comments; |
|
@item |
|
designated struct initializers (@samp{struct s x = @{ .i = 17 @};}) |
|
@item |
|
compound literals (@samp{x = (struct s) @{ 17, 23 @};}) |
|
@end itemize |
|
|
|
These features are supported by all compilers we care about, so we will not |
|
accept patches to remove their use unless they absolutely do not impair |
|
clarity and performance. |
|
|
|
All code must compile with GCC 2.95 and GCC 3.3. Currently, FFmpeg also |
|
compiles with several other compilers, such as the Compaq ccc compiler |
|
or Sun Studio 9, and we would like to keep it that way unless it would |
|
be exceedingly involved. To ensure compatibility, please do not use any |
|
additional C99 features or GCC extensions. Especially watch out for: |
|
@itemize @bullet |
|
@item |
|
mixing statements and declarations; |
|
@item |
|
@samp{long long} (use @samp{int64_t} instead); |
|
@item |
|
@samp{__attribute__} not protected by @samp{#ifdef __GNUC__} or similar; |
|
@item |
|
GCC statement expressions (@samp{(x = (@{ int y = 4; y; @})}). |
|
@end itemize |
|
|
|
Indent size is 4. |
|
The presentation is the one specified by 'indent -i4 -kr -nut'. |
|
The TAB character is forbidden outside of Makefiles as is any |
|
form of trailing whitespace. Commits containing either will be |
|
rejected by the Subversion repository. |
|
|
|
The main priority in FFmpeg is simplicity and small code size in order to |
|
minimize the bug count. |
|
|
|
Comments: Use the JavaDoc/Doxygen |
|
format (see examples below) so that code documentation |
|
can be generated automatically. All nontrivial functions should have a comment |
|
above them explaining what the function does, even if it is just one sentence. |
|
All structures and their member variables should be documented, too. |
|
@example |
|
/** |
|
* @@file mpeg.c |
|
* MPEG codec. |
|
* @@author ... |
|
*/ |
|
|
|
/** |
|
* Summary sentence. |
|
* more text ... |
|
* ... |
|
*/ |
|
typedef struct Foobar@{ |
|
int var1; /**< var1 description */ |
|
int var2; ///< var2 description |
|
/** var3 description */ |
|
int var3; |
|
@} Foobar; |
|
|
|
/** |
|
* Summary sentence. |
|
* more text ... |
|
* ... |
|
* @@param my_parameter description of my_parameter |
|
* @@return return value description |
|
*/ |
|
int myfunc(int my_parameter) |
|
... |
|
@end example |
|
|
|
fprintf and printf are forbidden in libavformat and libavcodec, |
|
please use av_log() instead. |
|
|
|
Casts should be used only when necessary. Unneeded parentheses |
|
should also be avoided if they don't make the code easier to understand. |
|
|
|
@section Development Policy |
|
|
|
@enumerate |
|
@item |
|
Contributions should be licensed under the LGPL 2.1, including an |
|
"or any later version" clause, or the MIT license. GPL 2 including |
|
an "or any later version" clause is also acceptable, but LGPL is |
|
preferred. |
|
@item |
|
You must not commit code which breaks FFmpeg! (Meaning unfinished but |
|
enabled code which breaks compilation or compiles but does not work or |
|
breaks the regression tests) |
|
You can commit unfinished stuff (for testing etc), but it must be disabled |
|
(#ifdef etc) by default so it does not interfere with other developers' |
|
work. |
|
@item |
|
You do not have to over-test things. If it works for you, and you think it |
|
should work for others, then commit. If your code has problems |
|
(portability, triggers compiler bugs, unusual environment etc) they will be |
|
reported and eventually fixed. |
|
@item |
|
Do not commit unrelated changes together, split them into self-contained |
|
pieces. Also do not forget that if part B depends on part A, but A does not |
|
depend on B, then A can and should be committed first and separate from B. |
|
Keeping changes well split into self-contained parts makes reviewing and |
|
understanding them on the commit log mailing list easier. This also helps |
|
in case of debugging later on. |
|
Also if you have doubts about splitting or not splitting, do not hesitate to |
|
ask/discuss it on the developer mailing list. |
|
@item |
|
Do not change behavior of the program (renaming options etc) without |
|
first discussing it on the ffmpeg-devel mailing list. Do not remove |
|
functionality from the code. Just improve! |
|
|
|
Note: Redundant code can be removed. |
|
@item |
|
Do not commit changes to the build system (Makefiles, configure script) |
|
which change behavior, defaults etc, without asking first. The same |
|
applies to compiler warning fixes, trivial looking fixes and to code |
|
maintained by other developers. We usually have a reason for doing things |
|
the way we do. Send your changes as patches to the ffmpeg-devel mailing |
|
list, and if the code maintainers say OK, you may commit. This does not |
|
apply to files you wrote and/or maintain. |
|
@item |
|
We refuse source indentation and other cosmetic changes if they are mixed |
|
with functional changes, such commits will be rejected and removed. Every |
|
developer has his own indentation style, you should not change it. Of course |
|
if you (re)write something, you can use your own style, even though we would |
|
prefer if the indentation throughout FFmpeg was consistent (Many projects |
|
force a given indentation style - we do not.). If you really need to make |
|
indentation changes (try to avoid this), separate them strictly from real |
|
changes. |
|
|
|
NOTE: If you had to put if()@{ .. @} over a large (> 5 lines) chunk of code, |
|
then either do NOT change the indentation of the inner part within (do not |
|
move it to the right)! or do so in a separate commit |
|
@item |
|
Always fill out the commit log message. Describe in a few lines what you |
|
changed and why. You can refer to mailing list postings if you fix a |
|
particular bug. Comments such as "fixed!" or "Changed it." are unacceptable. |
|
@item |
|
If you apply a patch by someone else, include the name and email address in |
|
the log message. Since the ffmpeg-cvslog mailing list is publicly |
|
archived you should add some SPAM protection to the email address. Send an |
|
answer to ffmpeg-devel (or wherever you got the patch from) saying that |
|
you applied the patch. |
|
@item |
|
When applying patches that have been discussed (at length) on the mailing |
|
list, reference the thread in the log message. |
|
@item |
|
Do NOT commit to code actively maintained by others without permission. |
|
Send a patch to ffmpeg-devel instead. If no one answers within a reasonable |
|
timeframe (12h for build failures and security fixes, 3 days small changes, |
|
1 week for big patches) then commit your patch if you think it is OK. |
|
Also note, the maintainer can simply ask for more time to review! |
|
@item |
|
Subscribe to the ffmpeg-cvslog mailing list. The diffs of all commits |
|
are sent there and reviewed by all the other developers. Bugs and possible |
|
improvements or general questions regarding commits are discussed there. We |
|
expect you to react if problems with your code are uncovered. |
|
@item |
|
Update the documentation if you change behavior or add features. If you are |
|
unsure how best to do this, send a patch to ffmpeg-devel, the documentation |
|
maintainer(s) will review and commit your stuff. |
|
@item |
|
Try to keep important discussions and requests (also) on the public |
|
developer mailing list, so that all developers can benefit from them. |
|
@item |
|
Never write to unallocated memory, never write over the end of arrays, |
|
always check values read from some untrusted source before using them |
|
as array index or other risky things. |
|
@item |
|
Remember to check if you need to bump versions for the specific libav |
|
parts (libavutil, libavcodec, libavformat) you are changing. You need |
|
to change the version integer and the version string. |
|
Incrementing the first component means no backward compatibility to |
|
previous versions (e.g. removal of a function from the public API). |
|
Incrementing the second component means backward compatible change |
|
(e.g. addition of a function to the public API). |
|
Incrementing the third component means a noteworthy binary compatible |
|
change (e.g. encoder bug fix that matters for the decoder). |
|
@item |
|
If you add a new codec, remember to update the changelog, add it to |
|
the supported codecs table in the documentation and bump the second |
|
component of the @file{libavcodec} version number appropriately. If |
|
it has a fourcc, add it to @file{libavformat/avienc.c}, even if it |
|
is only a decoder. |
|
@item |
|
Do not change code to hide warnings without ensuring that the underlying |
|
logic is correct and thus the warning was inappropriate. |
|
@item |
|
If you add a new file, give it a proper license header. Do not copy and |
|
paste it from a random place, use an existing file as template. |
|
@end enumerate |
|
|
|
We think our rules are not too hard. If you have comments, contact us. |
|
|
|
Note, these rules are mostly borrowed from the MPlayer project. |
|
|
|
@section Submitting patches |
|
|
|
First, (@pxref{Coding Rules}) above if you did not yet. |
|
|
|
When you submit your patch, try to send a unified diff (diff '-up' |
|
option). We cannot read other diffs :-) |
|
|
|
Also please do not submit a patch which contains several unrelated changes. |
|
Split it into separate, self-contained pieces. This does not mean splitting |
|
file by file. Instead, make the patch as small as possible while still |
|
keeping it as a logical unit that contains an individual change, even |
|
if it spans multiple files. This makes reviewing your patches much easier |
|
for us and greatly increases your chances of getting your patch applied. |
|
|
|
Run the regression tests before submitting a patch so that you can |
|
verify that there are no big problems. |
|
|
|
Patches should be posted as base64 encoded attachments (or any other |
|
encoding which ensures that the patch will not be trashed during |
|
transmission) to the ffmpeg-devel mailing list, see |
|
@url{http://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel} |
|
|
|
It also helps quite a bit if you tell us what the patch does (for example |
|
'replaces lrint by lrintf'), and why (for example '*BSD isn't C99 compliant |
|
and has no lrint()') |
|
|
|
Also please if you send several patches, send each patch as a separate mail, |
|
do not attach several unrelated patches to the same mail. |
|
|
|
@section patch submission checklist |
|
|
|
@enumerate |
|
@item |
|
Do the regression tests pass with the patch applied? |
|
@item |
|
Is the patch a unified diff? |
|
@item |
|
Is the patch against latest FFmpeg SVN? |
|
@item |
|
Are you subscribed to ffmpeg-dev? |
|
(the list is subscribers only due to spam) |
|
@item |
|
Have you checked that the changes are minimal, so that the same cannot be |
|
achieved with a smaller patch and/or simpler final code? |
|
@item |
|
If the change is to speed critical code, did you benchmark it? |
|
@item |
|
If you did any benchmarks, did you provide them in the mail? |
|
@item |
|
Have you checked that the patch does not introduce buffer overflows or |
|
other security issues? |
|
@item |
|
Is the patch created from the root of the source tree, so it can be |
|
applied with @code{patch -p0}? |
|
@item |
|
Does the patch not mix functional and cosmetic changes? |
|
@item |
|
Did you add tabs or trailing whitespace to the code? Both are forbidden. |
|
@item |
|
Is the patch attached to the email you send? |
|
@item |
|
Is the mime type of the patch correct? It should be text/x-diff or |
|
text/x-patch or at least text/plain and not application/octet-stream. |
|
@item |
|
If the patch fixes a bug, did you provide a verbose analysis of the bug? |
|
@item |
|
If the patch fixes a bug, did you provide enough information, including |
|
a sample, so the bug can be reproduced and the fix can be verified? |
|
Note please do not attach samples >100k to mails but rather provide a |
|
URL, you can upload to ftp://upload.mplayerhq.hu |
|
@item |
|
Did you provide a verbose summary about what the patch does change? |
|
@item |
|
Did you provide a verbose explanation why it changes things like it does? |
|
@item |
|
Did you provide a verbose summary of the user visible advantages and |
|
disadvantages if the patch is applied? |
|
@item |
|
Did you provide an example so we can verify the new feature added by the |
|
patch easily? |
|
@item |
|
If you added a new file, did you insert a license header? It should be |
|
taken from FFmpeg, not randomly copied and pasted from somewhere else. |
|
@item |
|
You should maintain alphabetical order in alphabetically ordered lists as |
|
long as doing so does not break API/ABI compatibility. |
|
@item |
|
Lines with similar content should be aligned vertically when doing so |
|
improves readability. |
|
@item |
|
Did you provide a suggestion for a clear commit log message? |
|
@end enumerate |
|
|
|
@section Patch review process |
|
|
|
All patches posted to ffmpeg-devel will be reviewed, unless they contain a |
|
clear note that the patch is not for SVN. |
|
Reviews and comments will be posted as replies to the patch on the |
|
mailing list. The patch submitter then has to take care of every comment, |
|
that can be by resubmitting a changed patch or by discussion. Resubmitted |
|
patches will themselves be reviewed like any other patch. If at some point |
|
a patch passes review with no comments then it is approved, that can for |
|
simple and small patches happen immediately while large patches will generally |
|
have to be changed and reviewed many times before they are approved. |
|
After a patch is approved it will be committed to the repository. |
|
|
|
We will review all submitted patches, but sometimes we are quite busy so |
|
especially for large patches this can take several weeks. |
|
|
|
When resubmitting patches, please do not make any significant changes |
|
not related to the comments received during review. Such patches will |
|
be rejected. Instead, submit significant changes or new features as |
|
separate patches. |
|
|
|
@section Regression tests |
|
|
|
Before submitting a patch (or committing to the repository), you should at least |
|
test that you did not break anything. |
|
|
|
The regression tests build a synthetic video stream and a synthetic |
|
audio stream. These are then encoded and decoded with all codecs or |
|
formats. The CRC (or MD5) of each generated file is recorded in a |
|
result file. A 'diff' is launched to compare the reference results and |
|
the result file. |
|
|
|
The regression tests then go on to test the FFserver code with a |
|
limited set of streams. It is important that this step runs correctly |
|
as well. |
|
|
|
Run 'make test' to test all the codecs and formats. |
|
|
|
Run 'make fulltest' to test all the codecs, formats and FFserver. |
|
|
|
[Of course, some patches may change the results of the regression tests. In |
|
this case, the reference results of the regression tests shall be modified |
|
accordingly]. |
|
|
|
@bye
|
|
|