Remove pointless #if around the file, it is already conditionally compiled.
[libav.git] / doc / general.texi
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1\input texinfo @c -*- texinfo -*-
2
3@settitle General Documentation
4@titlepage
5@sp 7
6@center @titlefont{General Documentation}
7@sp 3
8@end titlepage
9
10
11@chapter external libraries
12
13FFmpeg can be hooked up with a number of external libraries to add support
14for more formats. None of them are used by default, their use has to be
15explicitly requested by passing the appropriate flags to @file{./configure}.
16
17@section AMR
18
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19AMR comes in two different flavors, wideband and narrowband. FFmpeg can make
20use of the AMR wideband (floating-point mode) and the AMR narrowband
21(floating-point mode) reference decoders and encoders.
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22
23Go to @url{http://www.penguin.cz/~utx/amr} and follow the instructions for
24installing the libraries. Then pass @code{--enable-libamr-nb} and/or
25@code{--enable-libamr-wb} to configure to enable the libraries.
26
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27Note that libamr is copyrighted without any sort of license grant. This means
28that you can use it if you legally obtained it but you are not allowed to
29redistribute it in any way. @strong{Any FFmpeg binaries with libamr support
30you create are non-free and unredistributable!}
31
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32
33@chapter Supported File Formats and Codecs
34
35You can use the @code{-formats} option to have an exhaustive list.
36
37@section File Formats
38
39FFmpeg supports the following file formats through the @code{libavformat}
40library:
41
42@multitable @columnfractions .4 .1 .1 .4
b3de4544 43@item Name @tab Encoding @tab Decoding @tab Comments
64c2f20a 44@item 4xm @tab @tab X
c6b2dc34 45 @tab 4X Technologies format, used in some games.
39271be4 46@item Audio IFF (AIFF) @tab X @tab X
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47@item American Laser Games MM @tab @tab X
48 @tab Multimedia format used in games like Mad Dog McCree.
39271be4 49@item 3GPP AMR @tab X @tab X
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50@item ASF @tab X @tab X
51@item AVI @tab X @tab X
39271be4 52@item AVISynth @tab @tab X
c6b2dc34 53@item AVS @tab @tab X
d698c5d3 54 @tab Multimedia format used by the Creature Shock game.
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55@item Beam Software SIFF @tab @tab X
56 @tab Audio and video format used in some games by Beam Software.
57@item Bethesda Softworks VID @tab @tab X
d698c5d3 58 @tab Used in some games from Bethesda Softworks.
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59@item Brute Force & Ignorance @tab @tab X
60 @tab Used in the game Flash Traffic: City of Angels.
61@item Interplay C93 @tab @tab X
d698c5d3 62 @tab Used in the game Cyberia from Interplay.
913c3e2c 63@item Delphine Software International CIN @tab @tab X
d698c5d3 64 @tab Multimedia format used by Delphine Software games.
39271be4 65@item CRC testing format @tab X @tab
913c3e2c 66@item Creative Voice @tab X @tab X
d698c5d3 67 @tab Created for the Sound Blaster Pro.
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68@item CRYO APC @tab @tab X
69 @tab Audio format used in some games by CRYO Interactive Entertainment.
39271be4 70@item D-Cinema audio @tab X @tab X
913c3e2c 71@item DV video @tab X @tab X
c6b2dc34 72@item DXA @tab @tab X
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73 @tab This format is used in the non-Windows version of the Feeble Files
74 game and different game cutscenes repacked for use with ScummVM.
39271be4 75@item Electronic Arts cdata @tab @tab X
c6b2dc34 76@item Electronic Arts Multimedia @tab @tab X
d698c5d3 77 @tab Used in various EA games; files have extensions like WVE and UV2.
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78@item FFM (FFserver live feed) @tab X @tab X
79@item Flash (SWF) @tab X @tab X
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80@item Flash 9 (AVM2) @tab X @tab X
81 @tab Only embedded audio is decoded.
82@item FLI/FLC/FLX animation @tab @tab X
d698c5d3 83 @tab .fli/.flc files
c6b2dc34 84@item FLV @tab X @tab X
d698c5d3 85 @tab Macromedia Flash video files
39271be4 86@item framecrc testing format @tab X @tab
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87@item FunCom ISS @tab @tab X
88 @tab Audio format used in various games from FunCom like The Longest Journey.
39271be4 89@item GIF Animation @tab X @tab
c6b2dc34 90@item GXF @tab X @tab X
d698c5d3 91 @tab General eXchange Format SMPTE 360M, used by Thomson Grass Valley
64c2f20a 92 playout servers.
76ec3939 93@item id Cinematic @tab @tab X
d698c5d3 94 @tab Used in Quake II.
76ec3939 95@item id RoQ @tab X @tab X
d698c5d3 96 @tab Used in Quake III, Jedi Knight 2, other computer games.
c6b2dc34 97@item IFF @tab @tab X
d698c5d3 98 @tab Interchange File Format
c6b2dc34 99@item Interplay MVE @tab @tab X
d698c5d3 100 @tab Format used in various Interplay computer games.
c6b2dc34 101@item LMLM4 @tab @tab X
d698c5d3 102 @tab Used by Linux Media Labs MPEG-4 PCI boards
64c2f20a 103@item Matroska @tab X @tab X
39271be4 104@item Matroska audio @tab X @tab
913c3e2c 105@item MAXIS XA @tab @tab X
d698c5d3 106 @tab Used in Sim City 3000; file extension .xa.
64c2f20a 107@item Monkey's Audio @tab @tab X
822cc8f7 108@item Motion Pixels MVI @tab @tab X
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109@item MOV/QuickTime/MP4 @tab X @tab X
110 @tab 3GP, 3GP2, PSP, iPod variants supported
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111@item MP2 @tab X @tab
112@item MP3 @tab X @tab
c6b2dc34 113@item MPEG audio @tab X @tab X
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114@item MPEG-1 System @tab X @tab X
115 @tab muxed audio and video, VCD format supported
116@item MPEG-PS (program stream) @tab X @tab X
117 @tab also known as @code{VOB} file, SVCD and DVD format supported
118@item MPEG-TS (transport stream) @tab X @tab X
d698c5d3 119 @tab also known as DVB Transport Stream
c6b2dc34 120@item MPEG-4 @tab X @tab X
d698c5d3 121 @tab MPEG-4 is a variant of QuickTime.
39271be4 122@item MIME multipart JPEG @tab X @tab
bac4c85c 123@item MSN TCP webcam @tab @tab X
d698c5d3 124 @tab Used by MSN Messenger webcam streams.
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125@item MTV @tab @tab X
126@item Musepack @tab @tab X
127@item Musepack SV8 @tab @tab X
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128@item Material eXchange Format (MXF) @tab X @tab X
129 @tab SMPTE 377M, used by D-Cinema, broadcast industry.
130@item NC camera feed @tab @tab X
131 @tab NC (AVIP NC4600) camera streams
132@item Nullsoft Streaming Video @tab @tab X
39271be4 133@item NuppelVideo @tab @tab X
c6b2dc34 134@item NUT @tab X @tab X
d698c5d3 135 @tab NUT Open Container Format
39271be4 136@item Ogg @tab X @tab X
913c3e2c 137@item TechnoTrend PVA @tab @tab X
d698c5d3 138 @tab Used by TechnoTrend DVB PCI boards.
43dedc1e 139@item raw ADTS (AAC) @tab X @tab X
76ec3939 140@item raw AC-3 @tab X @tab X
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141@item raw CRI ADX @tab X @tab X
142@item raw Dirac @tab X @tab X
143@item raw DNxHD @tab X @tab X
144@item raw DTS @tab X @tab X
145@item raw E-AC-3 @tab X @tab X
146@item raw FLAC @tab X @tab X
147@item raw GSM @tab @tab X
148@item raw H.261 @tab X @tab X
149@item raw H.263 @tab X @tab X
150@item raw H.264 @tab X @tab X
151@item raw Ingenient MJPEG @tab @tab X
76ec3939 152@item raw MJPEG @tab X @tab X
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153@item raw MLP @tab @tab X
154@item raw MPEG @tab @tab X
155@item raw MPEG-1 @tab @tab X
156@item raw MPEG-2 @tab @tab X
157@item raw MPEG-4 @tab X @tab X
158@item raw NULL @tab X @tab
81b55ee5 159@item raw video @tab X @tab X
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160@item raw id RoQ @tab X @tab
161@item raw Shorten @tab @tab X
162@item raw VC-1 @tab @tab X
163@item raw PCM A-law @tab X @tab X
164@item raw PCM mu-law @tab X @tab X
165@item raw PCM signed 8 bit @tab X @tab X
166@item raw PCM signed 16 bit big-endian @tab X @tab X
167@item raw PCM signed 16 bit little-endian @tab X @tab X
168@item raw PCM signed 24 bit big-endian @tab X @tab X
169@item raw PCM signed 24 bit little-endian @tab X @tab X
170@item raw PCM signed 32 bit big-endian @tab X @tab X
171@item raw PCM signed 32 bit little-endian @tab X @tab X
172@item raw PCM unsigned 8 bit @tab X @tab X
173@item raw PCM unsigned 16 bit big-endian @tab X @tab X
174@item raw PCM unsigned 16 bit little-endian @tab X @tab X
175@item raw PCM unsigned 24 bit big-endian @tab X @tab X
176@item raw PCM unsigned 24 bit little-endian @tab X @tab X
177@item raw PCM unsigned 32 bit big-endian @tab X @tab X
178@item raw PCM unsigned 32 bit little-endian @tab X @tab X
179@item raw PCM floating-point 32 bit big-endian @tab X @tab X
180@item raw PCM floating-point 32 bit little-endian @tab X @tab X
181@item raw PCM floating-point 64 bit big-endian @tab X @tab X
182@item raw PCM floating-point 64 bit little-endian @tab X @tab X
39271be4 183@item RDT @tab @tab X
913c3e2c 184@item REDCODE R3D @tab @tab X
7eb68edb 185 @tab File format used by RED Digital cameras, contains JPEG 2000 frames and PCM audio.
64c2f20a 186@item RealMedia @tab X @tab X
39271be4 187@item Redirector @tab @tab X
913c3e2c 188@item Renderware TeXture Dictionary @tab @tab X
c6b2dc34 189@item RL2 @tab @tab X
d698c5d3 190 @tab Audio and video format used in some games by Entertainment Software Partners.
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191@item RPL/ARMovie @tab @tab X
192@item RTP @tab @tab X
193@item RTSP @tab @tab X
194@item SDP @tab @tab X
c6b2dc34 195@item Sega FILM/CPK @tab @tab X
d698c5d3 196 @tab Used in many Sega Saturn console games.
913c3e2c 197@item Sierra SOL @tab @tab X
d698c5d3 198 @tab .sol files used in Sierra Online games.
c6b2dc34 199@item Sierra VMD @tab @tab X
d698c5d3 200 @tab Used in Sierra CD-ROM games.
c6b2dc34 201@item Smacker @tab @tab X
d698c5d3 202 @tab Multimedia format used by many games.
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203@item Sony OpenMG (OMA) @tab @tab X
204 @tab Audio format used in Sony Sonic Stage and Sony Vegas.
205@item Sony PlayStation STR @tab @tab X
64c2f20a 206@item SUN AU format @tab X @tab X
c6b2dc34 207@item THP @tab @tab X
d698c5d3 208 @tab Used on the Nintendo GameCube.
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209@item Tiertex Limited SEQ @tab @tab X
210 @tab Tiertex .seq files used in the DOS CD-ROM version of the game Flashback.
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211@item True Audio @tab @tab X
212@item VC-1 test bitstream @tab X @tab X
c6b2dc34 213@item WAV @tab X @tab X
39271be4 214@item WavPack @tab @tab X
913c3e2c 215@item Wing Commander III movie @tab @tab X
d698c5d3 216 @tab Multimedia format used in Origin's Wing Commander III computer game.
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217@item Westwood Studios audio @tab @tab X
218 @tab Multimedia format used in Westwood Studios games.
219@item Westwood Studios VQA @tab @tab X
220 @tab Multimedia format used in Westwood Studios games.
39271be4 221@item YUV4MPEG pipe @tab X @tab X
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222@end multitable
223
224@code{X} means that encoding (resp. decoding) is supported.
225
226@section Image Formats
227
228FFmpeg can read and write images for each frame of a video sequence. The
229following image formats are supported:
230
231@multitable @columnfractions .4 .1 .1 .4
b3de4544 232@item Name @tab Encoding @tab Decoding @tab Comments
64c2f20a 233@item .Y.U.V @tab X @tab X @tab one raw file per component
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234@item animated GIF @tab X @tab X @tab Only uncompressed GIFs are generated.
235@item JPEG @tab X @tab X @tab Progressive JPEG is not supported.
9a77d59a 236@item JPEG 2000 @tab @tab E @tab decoding supported through external library libopenjpeg
d0e1cd3d 237@item PAM @tab X @tab X @tab PAM is a PNM extension with alpha support.
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238@item PCX @tab @tab X @tab PC Paintbrush
239@item PGM, PPM @tab X @tab X
d0e1cd3d 240@item PGMYUV @tab X @tab X @tab PGM with U and V components in YUV 4:2:0
0a91f4ee 241@item PNG @tab X @tab X @tab 2/4 bpp not supported yet
d0e1cd3d 242@item PTX @tab @tab X @tab V.Flash PTX format
d1928ac1 243@item RAS @tab @tab X @tab Sun Rasterfile
3d172fb5 244@item SGI @tab X @tab X @tab SGI RGB image format
3d172fb5 245@item Targa @tab @tab X @tab Targa (.TGA) image format
64c2f20a 246@item TIFF @tab X @tab X @tab YUV, JPEG and some extension is not supported yet.
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247@end multitable
248
249@code{X} means that encoding (resp. decoding) is supported.
250
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251@code{E} means that support is provided through an external library.
252
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253@section Video Codecs
254
255@multitable @columnfractions .4 .1 .1 .4
b3de4544 256@item Name @tab Encoding @tab Decoding @tab Comments
d66d8b83 257@item 4X Video @tab @tab X
d698c5d3 258 @tab Used in certain computer games.
913c3e2c 259@item American Laser Games MM @tab @tab X
d698c5d3 260 @tab Used in games like Mad Dog McCree.
d66d8b83 261@item AMV @tab @tab X
d698c5d3 262 @tab Used in Chinese MP3 players.
d66d8b83 263@item Apple Animation @tab X @tab X
d698c5d3 264 @tab fourcc: 'rle '
d66d8b83 265@item Apple Graphics @tab @tab X
d698c5d3 266 @tab fourcc: 'smc '
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267@item Apple MJPEG-B @tab @tab X
268@item Apple QuickDraw @tab @tab X
d698c5d3 269 @tab fourcc: qdrw
d66d8b83 270@item Apple Video @tab @tab X
d698c5d3 271 @tab fourcc: rpza
d66d8b83 272@item Asus v1 @tab X @tab X
d698c5d3 273 @tab fourcc: ASV1
d66d8b83 274@item Asus v2 @tab X @tab X
d698c5d3 275 @tab fourcc: ASV2
d66d8b83 276@item ATI VCR1 @tab @tab X
d698c5d3 277 @tab fourcc: VCR1
d66d8b83 278@item ATI VCR2 @tab @tab X
d698c5d3 279 @tab fourcc: VCR2
d66d8b83 280@item Autodesk RLE @tab @tab X
d698c5d3 281 @tab fourcc: AASC
d66d8b83 282@item AVID DNxHD @tab X @tab X
d698c5d3 283 @tab aka SMPTE VC3
bac4c85c 284@item AVS video @tab @tab X
d698c5d3 285 @tab Video encoding used by the Creature Shock game.
d66d8b83 286@item Bethsoft VID @tab @tab X
d698c5d3 287 @tab Used in some games from Bethesda Softworks.
bac4c85c 288@item C93 video @tab @tab X
d698c5d3 289 @tab Codec used in Cyberia game.
d66d8b83 290@item CamStudio @tab @tab X
d698c5d3 291 @tab fourcc: CSCD
bac4c85c 292@item Cin video @tab @tab X
d698c5d3 293 @tab Codec used in Delphine Software games.
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294@item Cinepak @tab @tab X
295@item Cirrus Logic AccuPak @tab @tab X
d698c5d3 296 @tab fourcc: CLJR
d66d8b83 297@item Creative YUV @tab @tab X
d698c5d3 298 @tab fourcc: CYUV
82ced5a9 299@item Dirac @tab E @tab E
360f980b 300 @tab supported through external libdirac/libschroedinger libraries
d66d8b83 301@item Duck TrueMotion v1 @tab @tab X
d698c5d3 302 @tab fourcc: DUCK
d66d8b83 303@item Duck TrueMotion v2 @tab @tab X
d698c5d3 304 @tab fourcc: TM20
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305@item DV @tab X @tab X
306@item DXA Video @tab @tab X
d698c5d3 307 @tab Codec originally used in Feeble Files game.
d66d8b83 308@item Electronic Arts CMV @tab @tab X
d698c5d3 309 @tab Used in NHL 95 game.
cfc78718 310@item Electronic Arts TGV @tab @tab X
42b30357 311@item Electronic Arts TGQ @tab @tab X
d8964f3a 312@item Electronic Arts TQI @tab @tab X
d66d8b83 313@item FFmpeg Video 1 @tab X @tab X
d698c5d3 314 @tab experimental lossless codec (fourcc: FFV1)
d66d8b83 315@item Flash Screen Video @tab X @tab X
d698c5d3 316 @tab fourcc: FSV1
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317@item FLIC video @tab @tab X
318@item FLV @tab X @tab X
d698c5d3 319 @tab Sorenson H.263 used in Flash
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320@item Fraps FPS1 @tab @tab X
321@item H.261 @tab X @tab X
322@item H.263(+) @tab X @tab X
d698c5d3 323 @tab also known as RealVideo 1.0
82ced5a9 324@item H.264 @tab E @tab X
360f980b 325 @tab encoding supported through external library libx264
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326@item HuffYUV @tab X @tab X
327@item IBM Ultimotion @tab @tab X
d698c5d3 328 @tab fourcc: ULTI
bac4c85c 329@item id Cinematic video @tab @tab X
d698c5d3 330 @tab Used in Quake II.
d66d8b83 331@item id RoQ @tab X @tab X
d698c5d3 332 @tab Used in Quake III, Jedi Knight 2, other computer games.
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333@item Intel Indeo 3 @tab @tab X
334@item Interplay Video @tab @tab X
d698c5d3 335 @tab Used in Interplay .MVE files.
d66d8b83 336@item JPEG-LS @tab X @tab X
d698c5d3 337 @tab fourcc: MJLS, lossless and near-lossless is supported.
d66d8b83 338@item KMVC @tab @tab X
d698c5d3 339 @tab Codec used in Worms games.
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340@item LOCO @tab @tab X
341@item lossless MJPEG @tab X @tab X
342@item Microsoft RLE @tab @tab X
343@item Microsoft Video-1 @tab @tab X
344@item Mimic @tab @tab X
d698c5d3 345 @tab Used in MSN Messenger Webcam streams.
d66d8b83 346@item Miro VideoXL @tab @tab X
d698c5d3 347 @tab fourcc: VIXL
d66d8b83 348@item MJPEG @tab X @tab X
822cc8f7 349@item Motion Pixels Video @tab @tab X
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350@item MPEG-1 @tab X @tab X
351@item MPEG-2 @tab X @tab X
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352@item MPEG-4 @tab X @tab X
353@item MSMPEG4 V1 @tab X @tab X
354@item MSMPEG4 V2 @tab X @tab X
355@item MSMPEG4 V3 @tab X @tab X
d66d8b83 356@item MSZH @tab @tab X
d698c5d3 357 @tab Part of LCL
d66d8b83 358@item On2 VP3 @tab @tab X
d698c5d3 359 @tab still experimental
d66d8b83 360@item On2 VP5 @tab @tab X
d698c5d3 361 @tab fourcc: VP50
d66d8b83 362@item On2 VP6 @tab @tab X
d698c5d3 363 @tab fourcc: VP60,VP61,VP62
d66d8b83 364@item planar RGB @tab @tab X
d698c5d3 365 @tab fourcc: 8BPS
d66d8b83 366@item QPEG @tab @tab X
d698c5d3 367 @tab fourccs: QPEG, Q1.0, Q1.1
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368@item RealVideo 1.0 @tab X @tab X
369@item RealVideo 2.0 @tab X @tab X
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370@item RealVideo 3.0 @tab @tab X
371 @tab still far from ideal
11c0f9ec 372@item RealVideo 4.0 @tab @tab X
d66d8b83 373@item Renderware TXD @tab @tab X
d698c5d3 374 @tab Texture dictionaries used by the Renderware Engine.
d66d8b83 375@item RTjpeg @tab @tab X
d698c5d3 376 @tab Video encoding used in NuppelVideo files.
bac4c85c 377@item Smacker video @tab @tab X
d698c5d3 378 @tab Video encoding used in Smacker.
d66d8b83 379@item Snow @tab X @tab X
d698c5d3 380 @tab experimental wavelet codec (fourcc: SNOW)
831ec935 381@item Sony PlayStation MDEC @tab @tab X
d66d8b83 382@item Sorenson Video 1 @tab X @tab X
d698c5d3 383 @tab fourcc: SVQ1
d66d8b83 384@item Sorenson Video 3 @tab @tab X
d698c5d3 385 @tab fourcc: SVQ3
d66d8b83 386@item Sunplus MJPEG @tab @tab X
d698c5d3 387 @tab fourcc: SP5X
d66d8b83 388@item TechSmith Camtasia @tab @tab X
d698c5d3 389 @tab fourcc: TSCC
82ced5a9 390@item Theora @tab E @tab X
360f980b 391 @tab encoding supported through external library libtheora
d66d8b83 392@item THP @tab @tab X
d698c5d3 393 @tab Used on the Nintendo GameCube.
bac4c85c 394@item Tiertex Seq video @tab @tab X
d698c5d3 395 @tab Codec used in DOS CD-ROM FlashBack game.
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396@item VC-1 @tab @tab X
397@item VMD Video @tab @tab X
d698c5d3 398 @tab Used in Sierra VMD files.
d66d8b83 399@item VMware Video @tab @tab X
d698c5d3 400 @tab Codec used in videos captured by VMware.
d0e1cd3d 401@item Westwood VQA @tab @tab X
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402@item Winnov WNV1 @tab @tab X
403@item WMV7 @tab X @tab X
404@item WMV8 @tab X @tab X
405@item WMV9 @tab @tab X
d698c5d3 406 @tab not completely working
d66d8b83 407@item Xan/WC3 @tab @tab X
d698c5d3 408 @tab Used in Wing Commander III .MVE files.
39271be4 409@item YAMAHA SMAF @tab X @tab X
d66d8b83 410@item ZLIB @tab X @tab X
d698c5d3 411 @tab part of LCL, encoder experimental
d66d8b83 412@item ZMBV @tab X @tab X
d698c5d3 413 @tab Encoder works only in PAL8.
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414@end multitable
415
416@code{X} means that encoding (resp. decoding) is supported.
417
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418@code{E} means that support is provided through an external library.
419
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420@section Audio Codecs
421
485ec4f1 422@multitable @columnfractions .4 .1 .1 .4
b3de4544 423@item Name @tab Encoding @tab Decoding @tab Comments
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424@item 4X IMA ADPCM @tab @tab X
425@item 8SVX audio @tab @tab X
82ced5a9 426@item AAC @tab E @tab X
360f980b 427 @tab encoding supported through external library libfaac
16d81b27 428@item AC-3 @tab IX @tab IX
82ced5a9 429@item AMR-NB @tab E @tab E
360f980b 430 @tab supported through external library libamrnb
82ced5a9 431@item AMR-WB @tab E @tab E
360f980b 432 @tab supported through external library libamrwb
16d81b27 433@item AMV IMA ADPCM @tab @tab X
d698c5d3 434 @tab Used in AMV files
833e90dd 435@item Apple lossless audio @tab X @tab X
d698c5d3 436 @tab QuickTime fourcc 'alac'
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437@item Apple MACE 3 @tab @tab X
438@item Apple MACE 6 @tab @tab X
439@item ATRAC 3 @tab @tab X
440@item CD-ROM XA ADPCM @tab @tab X
bac4c85c 441@item Cin audio @tab @tab X
d698c5d3 442 @tab Codec used in Delphine Software International games.
16d81b27 443@item Creative ADPCM @tab @tab X
d698c5d3 444 @tab 16 -> 4, 8 -> 4, 8 -> 3, 8 -> 2
16d81b27 445@item CRI ADX ADPCM @tab X @tab X
d698c5d3 446 @tab Used in Sega Dreamcast games.
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447@item DSP Group TrueSpeech @tab @tab X
448@item DTS Coherent Audio @tab @tab X
449@item Duck DK3 IMA ADPCM @tab @tab X
d698c5d3 450 @tab Used in some Sega Saturn console games.
16d81b27 451@item Duck DK4 IMA ADPCM @tab @tab X
d698c5d3 452 @tab Used in some Sega Saturn console games.
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453@item DV audio @tab @tab X
454@item Electronic Arts ADPCM @tab @tab X
d698c5d3 455 @tab Used in various EA titles.
44723c84 456@item Enhanced AC-3 @tab @tab X
9a584db4 457@item FLAC lossless audio @tab IX @tab X
16d81b27 458@item G.726 ADPCM @tab X @tab X
82ced5a9 459@item GSM @tab E @tab E
3f33271a 460 @tab supported through external library libgsm
82ced5a9 461@item GSM_MS @tab E @tab E
3f33271a 462 @tab supported through external library libgsm
16d81b27 463@item id RoQ DPCM @tab X @tab X
d698c5d3 464 @tab Used in Quake III, Jedi Knight 2, other computer games.
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465@item Intel Music Coder @tab @tab X
466@item Interplay MVE DPCM @tab @tab X
d698c5d3 467 @tab Used in various Interplay computer games.
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468@item ISS IMA ADPCM @tab @tab X
469 @tab Used in FunCom games.
16d81b27 470@item MAXIS EA ADPCM @tab @tab X
d698c5d3 471 @tab Used in Sim City 3000.
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472@item Microsoft ADPCM @tab X @tab X
473@item MLP/TrueHD @tab @tab X
d698c5d3 474 @tab Used in DVD-Audio and Blu-Ray discs.
16d81b27 475@item Monkey's Audio @tab @tab X
d698c5d3 476 @tab Only versions 3.97-3.99 are supported.
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477@item MPEG audio layer 3 @tab E @tab IX
478 @tab encoding supported through external library LAME
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479@item MPEG audio layer 2 @tab IX @tab IX
480@item MS IMA ADPCM @tab X @tab X
481@item Musepack @tab @tab X
d698c5d3 482 @tab SV7 and SV8 are supported.
755ba886 483@item Nellymoser ASAO @tab X @tab X
73b458e3 484@item QCELP / PureVoice @tab @tab X
16d81b27 485@item Qdesign QDM2 @tab @tab X
d698c5d3 486 @tab There are still some distortions.
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487@item QT IMA ADPCM @tab X @tab X
488@item RA144 @tab @tab X
d698c5d3 489 @tab Real 14400 bit/s codec
16d81b27 490@item RA288 @tab @tab X
d698c5d3 491 @tab Real 28800 bit/s codec
575a5bf2 492@item RADnet @tab IX @tab IX
a692130f 493 @tab Real low bitrate AC-3 codec
16d81b27 494@item Real COOK @tab @tab X
d698c5d3 495 @tab All versions except 5.1 are supported.
bac4c85c 496@item Shorten @tab @tab X
16d81b27 497@item Sierra Online DPCM @tab @tab X
d698c5d3 498 @tab Used in Sierra Online game audio files.
bac4c85c 499@item Smacker audio @tab @tab X
16d81b27 500@item SMJPEG IMA ADPCM @tab @tab X
d698c5d3 501 @tab Used in certain Loki game ports.
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502@item Sonic @tab X @tab X
503 @tab experimental codec
504@item Sonic lossless @tab X @tab X
505 @tab experimental codec
82ced5a9 506@item Speex @tab @tab E
360f980b 507 @tab supported through external library libspeex
16d81b27 508@item THP ADPCM @tab @tab X
d698c5d3 509 @tab Used on the Nintendo GameCube.
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510@item True Audio (TTA) @tab @tab X
511@item Vorbis @tab X @tab X
bac4c85c 512@item WavPack @tab @tab X
16d81b27 513@item Westwood Studios IMA ADPCM @tab @tab X
d698c5d3 514 @tab Used in Westwood Studios games like Command and Conquer.
bac4c85c 515@item WMA v1/v2 @tab X @tab X
16d81b27 516@item Xan DPCM @tab @tab X
d698c5d3 517 @tab Used in Origin's Wing Commander IV AVI files.
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518@end multitable
519
520@code{X} means that encoding (resp. decoding) is supported.
521
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522@code{E} means that support is provided through an external library.
523
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524@code{I} means that an integer-only version is available, too (ensures high
525performance on systems without hardware floating point support).
526
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527@section Subtitle Formats
528
485ec4f1 529@multitable @columnfractions .4 .1 .1 .1 .1 .1
9afc2917 530@item Name @tab Muxing @tab Demuxing @tab Encoding @tab Decoding
913c3e2c 531@item SSA/ASS @tab X @tab X
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532@item DVB @tab X @tab X @tab X @tab X
533@item DVD @tab X @tab X @tab X @tab X
534@item XSUB @tab @tab @tab @tab X
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535@end multitable
536
537@code{X} means that the feature is supported.
538
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539@chapter Platform Specific information
540
541@section BSD
542
543BSD make will not build FFmpeg, you need to install and use GNU Make
544(@file{gmake}).
545
546@section Windows
547
46a845d0 548To get help and instructions for building FFmpeg under Windows, check out
d0e1cd3d 549the FFmpeg Windows Help Forum at
ab5ce4ae 550@url{http://ffmpeg.arrozcru.org/}.
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551
552@subsection Native Windows compilation
553
c1989552 554FFmpeg can be built to run natively on Windows using the MinGW tools. Install
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555the latest versions of MSYS and MinGW from @url{http://www.mingw.org/}.
556You can find detailed installation
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557instructions in the download section and the FAQ.
558
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559FFmpeg does not build out-of-the-box with the packages the automated MinGW
560installer provides. It also requires coreutils to be installed and many other
561packages updated to the latest version. The minimum version for some packages
562are listed below:
563
564@itemize
565@item bash 3.1
566@item msys-make 3.81-2 (note: not mingw32-make)
2014b51c 567@item w32api 3.13
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568@item mingw-runtime 3.15
569@end itemize
570
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571You will also need to pass @code{-fno-common} to the compiler to work around
572a GCC bug (see @url{http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37216}).
573
c1989552 574Within the MSYS shell, configure and make with:
d0e1cd3d 575
c1989552 576@example
0f898714 577./configure --enable-memalign-hack --extra-cflags=-fno-common
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578make
579make install
580@end example
d0e1cd3d 581
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582This will install @file{ffmpeg.exe} along with many other development files
583to @file{/usr/local}. You may specify another install path using the
584@code{--prefix} option in @file{configure}.
d0e1cd3d 585
c1989552 586Notes:
d0e1cd3d 587
c1989552 588@itemize
d0e1cd3d 589
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590@item In order to compile vhooks, you must have a POSIX-compliant libdl in
591your MinGW system. Get dlfcn-win32 from
592@url{http://code.google.com/p/dlfcn-win32}.
d0e1cd3d 593
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594@item In order to compile FFplay, you must have the MinGW development library
595of SDL. Get it from @url{http://www.libsdl.org}.
596Edit the @file{bin/sdl-config} script so that it points to the correct prefix
597where SDL was installed. Verify that @file{sdl-config} can be launched from
598the MSYS command line.
d0e1cd3d 599
d0e1cd3d 600@item By using @code{./configure --enable-shared} when configuring FFmpeg,
c1989552 601you can build libavutil, libavcodec and libavformat as DLLs.
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602
603@end itemize
604
c1989552 605@subsection Microsoft Visual C++ compatibility
d0e1cd3d 606
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607As stated in the FAQ, FFmpeg will not compile under MSVC++. However, if you
608want to use the libav* libraries in your own applications, you can still
609compile those applications using MSVC++. But the libav* libraries you link
610to @emph{must} be built with MinGW. However, you will not be able to debug
611inside the libav* libraries, since MSVC++ does not recognize the debug
612symbols generated by GCC.
613We strongly recommend you to move over from MSVC++ to MinGW tools.
d0e1cd3d 614
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615This description of how to use the FFmpeg libraries with MSVC++ is based on
616Microsoft Visual C++ 2005 Express Edition. If you have a different version,
617you might have to modify the procedures slightly.
d0e1cd3d 618
c1989552 619@subsubsection Using static libraries
d0e1cd3d 620
c1989552 621Assuming you have just built and installed FFmpeg in @file{/usr/local}.
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622
623@enumerate
624
625@item Create a new console application ("File / New / Project") and then
626select "Win32 Console Application". On the appropriate page of the
627Application Wizard, uncheck the "Precompiled headers" option.
628
629@item Write the source code for your application, or, for testing, just
630copy the code from an existing sample application into the source file
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631that MSVC++ has already created for you. For example, you can copy
632@file{output_example.c} from the FFmpeg distribution.
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633
634@item Open the "Project / Properties" dialog box. In the "Configuration"
635combo box, select "All Configurations" so that the changes you make will
636affect both debug and release builds. In the tree view on the left hand
637side, select "C/C++ / General", then edit the "Additional Include
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638Directories" setting to contain the path where the FFmpeg includes were
639installed (i.e. @file{c:\msys\1.0\local\include}).
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640Do not add MinGW's include directory here, or the include files will
641conflict with MSVC's.
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642
643@item Still in the "Project / Properties" dialog box, select
644"Linker / General" from the tree view and edit the
645"Additional Library Directories" setting to contain the @file{lib}
646directory where FFmpeg was installed (i.e. @file{c:\msys\1.0\local\lib}),
647the directory where MinGW libs are installed (i.e. @file{c:\mingw\lib}),
648and the directory where MinGW's GCC libs are installed
649(i.e. @file{C:\mingw\lib\gcc\mingw32\4.2.1-sjlj}). Then select
650"Linker / Input" from the tree view, and add the files @file{libavformat.a},
651@file{libavcodec.a}, @file{libavutil.a}, @file{libmingwex.a},
652@file{libgcc.a}, and any other libraries you used (i.e. @file{libz.a})
653to the end of "Additional Dependencies".
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654
655@item Now, select "C/C++ / Code Generation" from the tree view. Select
656"Debug" in the "Configuration" combo box. Make sure that "Runtime
657Library" is set to "Multi-threaded Debug DLL". Then, select "Release" in
658the "Configuration" combo box and make sure that "Runtime Library" is
659set to "Multi-threaded DLL".
660
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661@item Click "OK" to close the "Project / Properties" dialog box.
662
663@item MSVC++ lacks some C99 header files that are fundamental for FFmpeg.
664Get msinttypes from @url{http://code.google.com/p/msinttypes/downloads/list}
665and install it in MSVC++'s include directory
666(i.e. @file{C:\Program Files\Microsoft Visual Studio 8\VC\include}).
667
668@item MSVC++ also does not understand the @code{inline} keyword used by
669FFmpeg, so you must add this line before @code{#include}ing libav*:
670@example
671#define inline _inline
672@end example
673
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674@item Build your application, everything should work.
675
676@end enumerate
677
678@subsubsection Using shared libraries
679
680This is how to create DLL and LIB files that are compatible with MSVC++:
681
682@enumerate
683
684@item Add a call to @file{vcvars32.bat} (which sets up the environment
685variables for the Visual C++ tools) as the first line of @file{msys.bat}.
686The standard location for @file{vcvars32.bat} is
687@file{C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat},
688and the standard location for @file{msys.bat} is @file{C:\msys\1.0\msys.bat}.
689If this corresponds to your setup, add the following line as the first line
690of @file{msys.bat}:
691
692@example
693call "C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat"
694@end example
695
696Alternatively, you may start the @file{Visual Studio 2005 Command Prompt},
697and run @file{c:\msys\1.0\msys.bat} from there.
698
699@item Within the MSYS shell, run @code{lib.exe}. If you get a help message
700from @file{Microsoft (R) Library Manager}, this means your environment
701variables are set up correctly, the @file{Microsoft (R) Library Manager}
702is on the path and will be used by FFmpeg to create
703MSVC++-compatible import libraries.
704
705@item Build FFmpeg with
706
707@example
708./configure --enable-shared --enable-memalign-hack
709make
710make install
711@end example
712
713Your install path (@file{/usr/local/} by default) should now have the
714necessary DLL and LIB files under the @file{bin} directory.
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715
716@end enumerate
717
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718To use those files with MSVC++, do the same as you would do with
719the static libraries, as described above. But in Step 4,
720you should only need to add the directory where the LIB files are installed
721(i.e. @file{c:\msys\usr\local\bin}). This is not a typo, the LIB files are
722installed in the @file{bin} directory. And instead of adding @file{libxx.a}
723files, you should add @file{avcodec.lib}, @file{avformat.lib}, and
724@file{avutil.lib}. There should be no need for @file{libmingwex.a},
725@file{libgcc.a}, and @file{wsock32.lib}, nor any other external library
726statically linked into the DLLs. The @file{bin} directory contains a bunch
727of DLL files, but the ones that are actually used to run your application
728are the ones with a major version number in their filenames
729(i.e. @file{avcodec-51.dll}).
730
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731@subsection Cross compilation for Windows with Linux
732
733You must use the MinGW cross compilation tools available at
734@url{http://www.mingw.org/}.
735
736Then configure FFmpeg with the following options:
737@example
738./configure --target-os=mingw32 --cross-prefix=i386-mingw32msvc-
739@end example
740(you can change the cross-prefix according to the prefix chosen for the
741MinGW tools).
742
743Then you can easily test FFmpeg with Wine
744(@url{http://www.winehq.com/}).
745
746@subsection Compilation under Cygwin
747
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748The main issue with the 1.5.x Cygwin versions is that newlib, its C library,
749does not contain llrint(). You need to upgrade to the unstable 1.7.x versions,
750or leverage the implementation in MinGW (as explained below).
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751
752Just install your Cygwin with all the "Base" packages, plus the
753following "Devel" ones:
754@example
f496ab12 755binutils, gcc-core, make, subversion, mingw-runtime, diffutils
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756@end example
757
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758The experimental gcc4 package is still buggy, hence please
759use the official gcc 3.4.4 or a 4.2.x compiled from source by yourself.
760
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761Install the current binutils-20080624-2 as they work fine (the old
762binutils-20060709-1 proved buggy on shared builds).
d0e1cd3d 763
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764Then create a small library that just contains llrint():
765
766@example
767ar x /usr/lib/mingw/libmingwex.a llrint.o
768ar cq /usr/local/lib/libllrint.a llrint.o
769@end example
770
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771Then run
772
773@example
29c3d42b 774./configure --enable-static --disable-shared --extra-ldflags='-L /usr/local/lib' --extra-libs='-l llrint'
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775@end example
776
777to make a static build or
778
779@example
29c3d42b 780./configure --enable-shared --disable-static --extra-ldflags='-L /usr/local/lib' --extra-libs='-l llrint'
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781@end example
782
783to build shared libraries.
784
785If you want to build FFmpeg with additional libraries, download Cygwin
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786"Devel" packages for Ogg and Vorbis from any Cygwin packages repository:
787@example
788libogg-devel, libvorbis-devel
789@end example
790
791These library packages are only available from Cygwin Ports
be8497b0 792(@url{http://sourceware.org/cygwinports/}) :
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793
794@example
795yasm, libSDL-devel, libdirac-devel, libfaac-devel, libfaad-devel, libgsm-devel,
796libmp3lame-devel, libschroedinger1.0-devel, speex-devel, libtheora-devel,
797libxvidcore-devel
798@end example
799
800The recommendation for libnut and x264 is to build them from source by
801yourself, as they evolve too quickly for Cygwin Ports to be up to date.
d0e1cd3d 802
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803Cygwin 1.7.x has IPv6 support. You can add IPv6 to Cygwin 1.5.x by means
804of the @code{libgetaddrinfo-devel} package, available at Cygwin Ports.
805
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806@subsection Crosscompilation for Windows under Cygwin
807
808With Cygwin you can create Windows binaries that do not need the cygwin1.dll.
809
810Just install your Cygwin as explained before, plus these additional
811"Devel" packages:
812@example
813gcc-mingw-core, mingw-runtime, mingw-zlib
814@end example
815
816and add some special flags to your configure invocation.
817
818For a static build run
819@example
820./configure --target-os=mingw32 --enable-memalign-hack --enable-static --disable-shared --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
821@end example
822
823and for a build with shared libraries
824@example
825./configure --target-os=mingw32 --enable-memalign-hack --enable-shared --disable-static --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
826@end example
827
828@section BeOS
829
5f757b85 830BeOS support is broken in mysterious ways.
d0e1cd3d 831
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832@section OS/2
833
834For information about compiling FFmpeg on OS/2 see
835@url{http://www.edm2.com/index.php/FFmpeg}.
836
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837@chapter Developers Guide
838
839@section API
840@itemize @bullet
841@item libavcodec is the library containing the codecs (both encoding and
842decoding). Look at @file{libavcodec/apiexample.c} to see how to use it.
843
844@item libavformat is the library containing the file format handling (mux and
845demux code for several formats). Look at @file{ffplay.c} to use it in a
846player. See @file{output_example.c} to use it to generate audio or video
847streams.
848
849@end itemize
850
851@section Integrating libavcodec or libavformat in your program
852
853You can integrate all the source code of the libraries to link them
854statically to avoid any version problem. All you need is to provide a
855'config.mak' and a 'config.h' in the parent directory. See the defines
856generated by ./configure to understand what is needed.
857
858You can use libavcodec or libavformat in your commercial program, but
859@emph{any patch you make must be published}. The best way to proceed is
860to send your patches to the FFmpeg mailing list.
861
862@node Coding Rules
863@section Coding Rules
864
865FFmpeg is programmed in the ISO C90 language with a few additional
866features from ISO C99, namely:
867@itemize @bullet
868@item
869the @samp{inline} keyword;
870@item
871@samp{//} comments;
872@item
873designated struct initializers (@samp{struct s x = @{ .i = 17 @};})
874@item
875compound literals (@samp{x = (struct s) @{ 17, 23 @};})
876@end itemize
877
878These features are supported by all compilers we care about, so we will not
879accept patches to remove their use unless they absolutely do not impair
880clarity and performance.
881
882All code must compile with GCC 2.95 and GCC 3.3. Currently, FFmpeg also
883compiles with several other compilers, such as the Compaq ccc compiler
884or Sun Studio 9, and we would like to keep it that way unless it would
885be exceedingly involved. To ensure compatibility, please do not use any
886additional C99 features or GCC extensions. Especially watch out for:
887@itemize @bullet
888@item
889mixing statements and declarations;
890@item
891@samp{long long} (use @samp{int64_t} instead);
892@item
893@samp{__attribute__} not protected by @samp{#ifdef __GNUC__} or similar;
894@item
895GCC statement expressions (@samp{(x = (@{ int y = 4; y; @})}).
896@end itemize
897
898Indent size is 4.
899The presentation is the one specified by 'indent -i4 -kr -nut'.
900The TAB character is forbidden outside of Makefiles as is any
901form of trailing whitespace. Commits containing either will be
902rejected by the Subversion repository.
903
904The main priority in FFmpeg is simplicity and small code size in order to
905minimize the bug count.
906
907Comments: Use the JavaDoc/Doxygen
908format (see examples below) so that code documentation
909can be generated automatically. All nontrivial functions should have a comment
910above them explaining what the function does, even if it is just one sentence.
911All structures and their member variables should be documented, too.
912@example
913/**
914 * @@file mpeg.c
915 * MPEG codec.
916 * @@author ...
917 */
918
919/**
920 * Summary sentence.
921 * more text ...
922 * ...
923 */
924typedef struct Foobar@{
925 int var1; /**< var1 description */
926 int var2; ///< var2 description
927 /** var3 description */
928 int var3;
929@} Foobar;
930
931/**
932 * Summary sentence.
933 * more text ...
934 * ...
935 * @@param my_parameter description of my_parameter
936 * @@return return value description
937 */
938int myfunc(int my_parameter)
939...
940@end example
941
942fprintf and printf are forbidden in libavformat and libavcodec,
943please use av_log() instead.
944
945Casts should be used only when necessary. Unneeded parentheses
946should also be avoided if they don't make the code easier to understand.
947
948@section Development Policy
949
950@enumerate
951@item
952 Contributions should be licensed under the LGPL 2.1, including an
953 "or any later version" clause, or the MIT license. GPL 2 including
954 an "or any later version" clause is also acceptable, but LGPL is
955 preferred.
956@item
957 You must not commit code which breaks FFmpeg! (Meaning unfinished but
958 enabled code which breaks compilation or compiles but does not work or
959 breaks the regression tests)
960 You can commit unfinished stuff (for testing etc), but it must be disabled
961 (#ifdef etc) by default so it does not interfere with other developers'
962 work.
963@item
964 You do not have to over-test things. If it works for you, and you think it
965 should work for others, then commit. If your code has problems
966 (portability, triggers compiler bugs, unusual environment etc) they will be
967 reported and eventually fixed.
968@item
969 Do not commit unrelated changes together, split them into self-contained
970 pieces. Also do not forget that if part B depends on part A, but A does not
971 depend on B, then A can and should be committed first and separate from B.
972 Keeping changes well split into self-contained parts makes reviewing and
973 understanding them on the commit log mailing list easier. This also helps
974 in case of debugging later on.
975 Also if you have doubts about splitting or not splitting, do not hesitate to
976 ask/discuss it on the developer mailing list.
977@item
978 Do not change behavior of the program (renaming options etc) without
979 first discussing it on the ffmpeg-devel mailing list. Do not remove
980 functionality from the code. Just improve!
981
982 Note: Redundant code can be removed.
983@item
984 Do not commit changes to the build system (Makefiles, configure script)
985 which change behavior, defaults etc, without asking first. The same
986 applies to compiler warning fixes, trivial looking fixes and to code
987 maintained by other developers. We usually have a reason for doing things
988 the way we do. Send your changes as patches to the ffmpeg-devel mailing
989 list, and if the code maintainers say OK, you may commit. This does not
990 apply to files you wrote and/or maintain.
991@item
992 We refuse source indentation and other cosmetic changes if they are mixed
993 with functional changes, such commits will be rejected and removed. Every
994 developer has his own indentation style, you should not change it. Of course
995 if you (re)write something, you can use your own style, even though we would
996 prefer if the indentation throughout FFmpeg was consistent (Many projects
997 force a given indentation style - we do not.). If you really need to make
998 indentation changes (try to avoid this), separate them strictly from real
999 changes.
1000
1001 NOTE: If you had to put if()@{ .. @} over a large (> 5 lines) chunk of code,
1002 then either do NOT change the indentation of the inner part within (do not
1003 move it to the right)! or do so in a separate commit
1004@item
1005 Always fill out the commit log message. Describe in a few lines what you
1006 changed and why. You can refer to mailing list postings if you fix a
1007 particular bug. Comments such as "fixed!" or "Changed it." are unacceptable.
1008@item
1009 If you apply a patch by someone else, include the name and email address in
1010 the log message. Since the ffmpeg-cvslog mailing list is publicly
1011 archived you should add some SPAM protection to the email address. Send an
1012 answer to ffmpeg-devel (or wherever you got the patch from) saying that
1013 you applied the patch.
1014@item
1015 When applying patches that have been discussed (at length) on the mailing
1016 list, reference the thread in the log message.
1017@item
1018 Do NOT commit to code actively maintained by others without permission.
1019 Send a patch to ffmpeg-devel instead. If no one answers within a reasonable
1020 timeframe (12h for build failures and security fixes, 3 days small changes,
1021 1 week for big patches) then commit your patch if you think it is OK.
1022 Also note, the maintainer can simply ask for more time to review!
1023@item
1024 Subscribe to the ffmpeg-cvslog mailing list. The diffs of all commits
1025 are sent there and reviewed by all the other developers. Bugs and possible
1026 improvements or general questions regarding commits are discussed there. We
1027 expect you to react if problems with your code are uncovered.
1028@item
1029 Update the documentation if you change behavior or add features. If you are
1030 unsure how best to do this, send a patch to ffmpeg-devel, the documentation
1031 maintainer(s) will review and commit your stuff.
1032@item
1033 Try to keep important discussions and requests (also) on the public
1034 developer mailing list, so that all developers can benefit from them.
1035@item
1036 Never write to unallocated memory, never write over the end of arrays,
1037 always check values read from some untrusted source before using them
1038 as array index or other risky things.
1039@item
1040 Remember to check if you need to bump versions for the specific libav
1041 parts (libavutil, libavcodec, libavformat) you are changing. You need
b98052d5 1042 to change the version integer.
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1043 Incrementing the first component means no backward compatibility to
1044 previous versions (e.g. removal of a function from the public API).
1045 Incrementing the second component means backward compatible change
b98052d5
PR
1046 (e.g. addition of a function to the public API or extension of an
1047 existing data structure).
d0e1cd3d
DB
1048 Incrementing the third component means a noteworthy binary compatible
1049 change (e.g. encoder bug fix that matters for the decoder).
1050@item
53407b64 1051 Compiler warnings indicate potential bugs or code with bad style. If a type of
9908c1a8
DB
1052 warning always points to correct and clean code, that warning should
1053 be disabled, not the code changed.
1054 Thus the remaining warnings can either be bugs or correct code.
beaa4a91 1055 If it is a bug, the bug has to be fixed. If it is not, the code should
9908c1a8
DB
1056 be changed to not generate a warning unless that causes a slowdown
1057 or obfuscates the code.
d0e1cd3d
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1058@item
1059 If you add a new file, give it a proper license header. Do not copy and
1060 paste it from a random place, use an existing file as template.
1061@end enumerate
1062
1063We think our rules are not too hard. If you have comments, contact us.
1064
1065Note, these rules are mostly borrowed from the MPlayer project.
1066
1067@section Submitting patches
1068
1069First, (@pxref{Coding Rules}) above if you did not yet.
1070
1071When you submit your patch, try to send a unified diff (diff '-up'
1072option). We cannot read other diffs :-)
1073
1074Also please do not submit a patch which contains several unrelated changes.
1075Split it into separate, self-contained pieces. This does not mean splitting
1076file by file. Instead, make the patch as small as possible while still
1077keeping it as a logical unit that contains an individual change, even
1078if it spans multiple files. This makes reviewing your patches much easier
1079for us and greatly increases your chances of getting your patch applied.
1080
1081Run the regression tests before submitting a patch so that you can
1082verify that there are no big problems.
1083
1084Patches should be posted as base64 encoded attachments (or any other
1085encoding which ensures that the patch will not be trashed during
1086transmission) to the ffmpeg-devel mailing list, see
1087@url{http://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel}
1088
1089It also helps quite a bit if you tell us what the patch does (for example
1090'replaces lrint by lrintf'), and why (for example '*BSD isn't C99 compliant
1091and has no lrint()')
1092
1093Also please if you send several patches, send each patch as a separate mail,
1094do not attach several unrelated patches to the same mail.
1095
28ce1839
RP
1096@section New codecs or formats checklist
1097
1098@enumerate
1099@item
1100 Did you use av_cold for codec initialization and close functions?
1101@item
1102 Did you add a long_name under NULL_IF_CONFIG_SMALL to the AVCodec or
1103 AVInputFormat/AVOutputFormat struct?
1104@item
1105 Did you bump the minor version number in @file{avcodec.h} or
1106 @file{avformat.h}?
1107@item
1108 Did you register it in @file{allcodecs.c} or @file{allformats.c}?
1109@item
1110 Did you add the CodecID to @file{avcodec.h}?
1111@item
1112 If it has a fourcc, did you add it to @file{libavformat/riff.c},
1113 even if it is only a decoder?
1114@item
1115 Did you add a rule to compile the appropriate files in the Makefile?
1116 Remember to do this even if you're just adding a format to a file that is
1117 already being compiled by some other rule, like a raw demuxer.
1118@item
1119 Did you add an entry to the table of supported formats or codecs in the
1120 documentation?
1121@item
1122 Did you add an entry in the Changelog?
1123@item
1124 If it depends on a parser or a library, did you add that dependency in
1125 configure?
1126@item
1127 Did you "svn add" the appropriate files before commiting?
1128@end enumerate
1129
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1130@section patch submission checklist
1131
1132@enumerate
1133@item
1134 Do the regression tests pass with the patch applied?
1135@item
2cdba8bf
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1136 Does @code{make checkheaders} pass with the patch applied?
1137@item
d0e1cd3d
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1138 Is the patch a unified diff?
1139@item
1140 Is the patch against latest FFmpeg SVN?
1141@item
1142 Are you subscribed to ffmpeg-dev?
1143 (the list is subscribers only due to spam)
1144@item
1145 Have you checked that the changes are minimal, so that the same cannot be
1146 achieved with a smaller patch and/or simpler final code?
1147@item
1148 If the change is to speed critical code, did you benchmark it?
1149@item
1150 If you did any benchmarks, did you provide them in the mail?
1151@item
1152 Have you checked that the patch does not introduce buffer overflows or
1153 other security issues?
1154@item
63d247ea
DB
1155 Did you test your decoder or demuxer against damaged data? If no, see
1156 tools/trasher and the noise bitstream filter. Your decoder or demuxer
1157 should not crash or end in a (near) infinite loop when fed damaged data.
b885e0db 1158@item
d0e1cd3d
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1159 Is the patch created from the root of the source tree, so it can be
1160 applied with @code{patch -p0}?
1161@item
1162 Does the patch not mix functional and cosmetic changes?
1163@item
1164 Did you add tabs or trailing whitespace to the code? Both are forbidden.
1165@item
1166 Is the patch attached to the email you send?
1167@item
1168 Is the mime type of the patch correct? It should be text/x-diff or
1169 text/x-patch or at least text/plain and not application/octet-stream.
1170@item
1171 If the patch fixes a bug, did you provide a verbose analysis of the bug?
1172@item
1173 If the patch fixes a bug, did you provide enough information, including
1174 a sample, so the bug can be reproduced and the fix can be verified?
1175 Note please do not attach samples >100k to mails but rather provide a
0fa5f24c 1176 URL, you can upload to ftp://upload.ffmpeg.org
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1177@item
1178 Did you provide a verbose summary about what the patch does change?
1179@item
1180 Did you provide a verbose explanation why it changes things like it does?
1181@item
1182 Did you provide a verbose summary of the user visible advantages and
1183 disadvantages if the patch is applied?
1184@item
1185 Did you provide an example so we can verify the new feature added by the
1186 patch easily?
1187@item
1188 If you added a new file, did you insert a license header? It should be
1189 taken from FFmpeg, not randomly copied and pasted from somewhere else.
1190@item
1191 You should maintain alphabetical order in alphabetically ordered lists as
1192 long as doing so does not break API/ABI compatibility.
1193@item
1194 Lines with similar content should be aligned vertically when doing so
1195 improves readability.
1196@item
1197 Did you provide a suggestion for a clear commit log message?
1198@end enumerate
1199
1200@section Patch review process
1201
1202All patches posted to ffmpeg-devel will be reviewed, unless they contain a
1203clear note that the patch is not for SVN.
1204Reviews and comments will be posted as replies to the patch on the
1205mailing list. The patch submitter then has to take care of every comment,
1206that can be by resubmitting a changed patch or by discussion. Resubmitted
1207patches will themselves be reviewed like any other patch. If at some point
1208a patch passes review with no comments then it is approved, that can for
1209simple and small patches happen immediately while large patches will generally
1210have to be changed and reviewed many times before they are approved.
1211After a patch is approved it will be committed to the repository.
1212
1213We will review all submitted patches, but sometimes we are quite busy so
1214especially for large patches this can take several weeks.
1215
1216When resubmitting patches, please do not make any significant changes
1217not related to the comments received during review. Such patches will
1218be rejected. Instead, submit significant changes or new features as
1219separate patches.
1220
1221@section Regression tests
1222
1223Before submitting a patch (or committing to the repository), you should at least
1224test that you did not break anything.
1225
1226The regression tests build a synthetic video stream and a synthetic
1227audio stream. These are then encoded and decoded with all codecs or
1228formats. The CRC (or MD5) of each generated file is recorded in a
1229result file. A 'diff' is launched to compare the reference results and
1230the result file.
1231
1232The regression tests then go on to test the FFserver code with a
1233limited set of streams. It is important that this step runs correctly
1234as well.
1235
1236Run 'make test' to test all the codecs and formats.
1237
1238Run 'make fulltest' to test all the codecs, formats and FFserver.
1239
1240[Of course, some patches may change the results of the regression tests. In
1241this case, the reference results of the regression tests shall be modified
1242accordingly].
1243
1244@bye