Check return value of frame_start(), this avoids a crash if AVCodecContext::get_buffe...
[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@section Network Protocols
540
541@multitable @columnfractions .4 .1 .1 .1 .1 .1
542@item Name @tab Support
543@item file @tab X
544@item Gopher @tab X
545@item HTTP @tab X
546@item pipe @tab X
547@item RTP @tab X
548@item TCP @tab X
549@item UDP @tab X
550@end multitable
551
552@code{X} means that the protocol is supported.
553
554
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555@chapter Platform Specific information
556
557@section BSD
558
559BSD make will not build FFmpeg, you need to install and use GNU Make
560(@file{gmake}).
561
562@section Windows
563
46a845d0 564To get help and instructions for building FFmpeg under Windows, check out
d0e1cd3d 565the FFmpeg Windows Help Forum at
ab5ce4ae 566@url{http://ffmpeg.arrozcru.org/}.
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567
568@subsection Native Windows compilation
569
c1989552 570FFmpeg can be built to run natively on Windows using the MinGW tools. Install
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571the latest versions of MSYS and MinGW from @url{http://www.mingw.org/}.
572You can find detailed installation
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573instructions in the download section and the FAQ.
574
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575FFmpeg does not build out-of-the-box with the packages the automated MinGW
576installer provides. It also requires coreutils to be installed and many other
577packages updated to the latest version. The minimum version for some packages
578are listed below:
579
580@itemize
581@item bash 3.1
582@item msys-make 3.81-2 (note: not mingw32-make)
2014b51c 583@item w32api 3.13
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584@item mingw-runtime 3.15
585@end itemize
586
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587You will also need to pass @code{-fno-common} to the compiler to work around
588a GCC bug (see @url{http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37216}).
589
c1989552 590Within the MSYS shell, configure and make with:
d0e1cd3d 591
c1989552 592@example
0f898714 593./configure --enable-memalign-hack --extra-cflags=-fno-common
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594make
595make install
596@end example
d0e1cd3d 597
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598This will install @file{ffmpeg.exe} along with many other development files
599to @file{/usr/local}. You may specify another install path using the
600@code{--prefix} option in @file{configure}.
d0e1cd3d 601
c1989552 602Notes:
d0e1cd3d 603
c1989552 604@itemize
d0e1cd3d 605
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606@item In order to compile vhooks, you must have a POSIX-compliant libdl in
607your MinGW system. Get dlfcn-win32 from
608@url{http://code.google.com/p/dlfcn-win32}.
d0e1cd3d 609
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610@item In order to compile FFplay, you must have the MinGW development library
611of SDL. Get it from @url{http://www.libsdl.org}.
612Edit the @file{bin/sdl-config} script so that it points to the correct prefix
613where SDL was installed. Verify that @file{sdl-config} can be launched from
614the MSYS command line.
d0e1cd3d 615
d0e1cd3d 616@item By using @code{./configure --enable-shared} when configuring FFmpeg,
c1989552 617you can build libavutil, libavcodec and libavformat as DLLs.
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618
619@end itemize
620
c1989552 621@subsection Microsoft Visual C++ compatibility
d0e1cd3d 622
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623As stated in the FAQ, FFmpeg will not compile under MSVC++. However, if you
624want to use the libav* libraries in your own applications, you can still
625compile those applications using MSVC++. But the libav* libraries you link
626to @emph{must} be built with MinGW. However, you will not be able to debug
627inside the libav* libraries, since MSVC++ does not recognize the debug
628symbols generated by GCC.
629We strongly recommend you to move over from MSVC++ to MinGW tools.
d0e1cd3d 630
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631This description of how to use the FFmpeg libraries with MSVC++ is based on
632Microsoft Visual C++ 2005 Express Edition. If you have a different version,
633you might have to modify the procedures slightly.
d0e1cd3d 634
c1989552 635@subsubsection Using static libraries
d0e1cd3d 636
c1989552 637Assuming you have just built and installed FFmpeg in @file{/usr/local}.
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638
639@enumerate
640
641@item Create a new console application ("File / New / Project") and then
642select "Win32 Console Application". On the appropriate page of the
643Application Wizard, uncheck the "Precompiled headers" option.
644
645@item Write the source code for your application, or, for testing, just
646copy the code from an existing sample application into the source file
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647that MSVC++ has already created for you. For example, you can copy
648@file{output_example.c} from the FFmpeg distribution.
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649
650@item Open the "Project / Properties" dialog box. In the "Configuration"
651combo box, select "All Configurations" so that the changes you make will
652affect both debug and release builds. In the tree view on the left hand
653side, select "C/C++ / General", then edit the "Additional Include
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654Directories" setting to contain the path where the FFmpeg includes were
655installed (i.e. @file{c:\msys\1.0\local\include}).
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656Do not add MinGW's include directory here, or the include files will
657conflict with MSVC's.
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658
659@item Still in the "Project / Properties" dialog box, select
660"Linker / General" from the tree view and edit the
661"Additional Library Directories" setting to contain the @file{lib}
662directory where FFmpeg was installed (i.e. @file{c:\msys\1.0\local\lib}),
663the directory where MinGW libs are installed (i.e. @file{c:\mingw\lib}),
664and the directory where MinGW's GCC libs are installed
665(i.e. @file{C:\mingw\lib\gcc\mingw32\4.2.1-sjlj}). Then select
666"Linker / Input" from the tree view, and add the files @file{libavformat.a},
667@file{libavcodec.a}, @file{libavutil.a}, @file{libmingwex.a},
668@file{libgcc.a}, and any other libraries you used (i.e. @file{libz.a})
669to the end of "Additional Dependencies".
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670
671@item Now, select "C/C++ / Code Generation" from the tree view. Select
672"Debug" in the "Configuration" combo box. Make sure that "Runtime
673Library" is set to "Multi-threaded Debug DLL". Then, select "Release" in
674the "Configuration" combo box and make sure that "Runtime Library" is
675set to "Multi-threaded DLL".
676
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677@item Click "OK" to close the "Project / Properties" dialog box.
678
679@item MSVC++ lacks some C99 header files that are fundamental for FFmpeg.
680Get msinttypes from @url{http://code.google.com/p/msinttypes/downloads/list}
681and install it in MSVC++'s include directory
682(i.e. @file{C:\Program Files\Microsoft Visual Studio 8\VC\include}).
683
684@item MSVC++ also does not understand the @code{inline} keyword used by
685FFmpeg, so you must add this line before @code{#include}ing libav*:
686@example
687#define inline _inline
688@end example
689
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690@item Build your application, everything should work.
691
692@end enumerate
693
694@subsubsection Using shared libraries
695
696This is how to create DLL and LIB files that are compatible with MSVC++:
697
698@enumerate
699
700@item Add a call to @file{vcvars32.bat} (which sets up the environment
701variables for the Visual C++ tools) as the first line of @file{msys.bat}.
702The standard location for @file{vcvars32.bat} is
703@file{C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat},
704and the standard location for @file{msys.bat} is @file{C:\msys\1.0\msys.bat}.
705If this corresponds to your setup, add the following line as the first line
706of @file{msys.bat}:
707
708@example
709call "C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat"
710@end example
711
712Alternatively, you may start the @file{Visual Studio 2005 Command Prompt},
713and run @file{c:\msys\1.0\msys.bat} from there.
714
715@item Within the MSYS shell, run @code{lib.exe}. If you get a help message
716from @file{Microsoft (R) Library Manager}, this means your environment
717variables are set up correctly, the @file{Microsoft (R) Library Manager}
718is on the path and will be used by FFmpeg to create
719MSVC++-compatible import libraries.
720
721@item Build FFmpeg with
722
723@example
724./configure --enable-shared --enable-memalign-hack
725make
726make install
727@end example
728
729Your install path (@file{/usr/local/} by default) should now have the
730necessary DLL and LIB files under the @file{bin} directory.
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731
732@end enumerate
733
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734To use those files with MSVC++, do the same as you would do with
735the static libraries, as described above. But in Step 4,
736you should only need to add the directory where the LIB files are installed
737(i.e. @file{c:\msys\usr\local\bin}). This is not a typo, the LIB files are
738installed in the @file{bin} directory. And instead of adding @file{libxx.a}
739files, you should add @file{avcodec.lib}, @file{avformat.lib}, and
740@file{avutil.lib}. There should be no need for @file{libmingwex.a},
741@file{libgcc.a}, and @file{wsock32.lib}, nor any other external library
742statically linked into the DLLs. The @file{bin} directory contains a bunch
743of DLL files, but the ones that are actually used to run your application
744are the ones with a major version number in their filenames
745(i.e. @file{avcodec-51.dll}).
746
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747@subsection Cross compilation for Windows with Linux
748
749You must use the MinGW cross compilation tools available at
750@url{http://www.mingw.org/}.
751
752Then configure FFmpeg with the following options:
753@example
754./configure --target-os=mingw32 --cross-prefix=i386-mingw32msvc-
755@end example
756(you can change the cross-prefix according to the prefix chosen for the
757MinGW tools).
758
759Then you can easily test FFmpeg with Wine
760(@url{http://www.winehq.com/}).
761
762@subsection Compilation under Cygwin
763
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764The main issue with the 1.5.x Cygwin versions is that newlib, its C library,
765does not contain llrint(). You need to upgrade to the unstable 1.7.x versions,
766or leverage the implementation in MinGW (as explained below).
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767
768Just install your Cygwin with all the "Base" packages, plus the
769following "Devel" ones:
770@example
f496ab12 771binutils, gcc-core, make, subversion, mingw-runtime, diffutils
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772@end example
773
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774The experimental gcc4 package is still buggy, hence please
775use the official gcc 3.4.4 or a 4.2.x compiled from source by yourself.
776
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777Install the current binutils-20080624-2 as they work fine (the old
778binutils-20060709-1 proved buggy on shared builds).
d0e1cd3d 779
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780Then create a small library that just contains llrint():
781
782@example
783ar x /usr/lib/mingw/libmingwex.a llrint.o
784ar cq /usr/local/lib/libllrint.a llrint.o
785@end example
786
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787Then run
788
789@example
29c3d42b 790./configure --enable-static --disable-shared --extra-ldflags='-L /usr/local/lib' --extra-libs='-l llrint'
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791@end example
792
793to make a static build or
794
795@example
29c3d42b 796./configure --enable-shared --disable-static --extra-ldflags='-L /usr/local/lib' --extra-libs='-l llrint'
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797@end example
798
799to build shared libraries.
800
801If you want to build FFmpeg with additional libraries, download Cygwin
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802"Devel" packages for Ogg and Vorbis from any Cygwin packages repository:
803@example
804libogg-devel, libvorbis-devel
805@end example
806
807These library packages are only available from Cygwin Ports
be8497b0 808(@url{http://sourceware.org/cygwinports/}) :
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809
810@example
811yasm, libSDL-devel, libdirac-devel, libfaac-devel, libfaad-devel, libgsm-devel,
812libmp3lame-devel, libschroedinger1.0-devel, speex-devel, libtheora-devel,
813libxvidcore-devel
814@end example
815
816The recommendation for libnut and x264 is to build them from source by
817yourself, as they evolve too quickly for Cygwin Ports to be up to date.
d0e1cd3d 818
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819Cygwin 1.7.x has IPv6 support. You can add IPv6 to Cygwin 1.5.x by means
820of the @code{libgetaddrinfo-devel} package, available at Cygwin Ports.
821
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822@subsection Crosscompilation for Windows under Cygwin
823
824With Cygwin you can create Windows binaries that do not need the cygwin1.dll.
825
826Just install your Cygwin as explained before, plus these additional
827"Devel" packages:
828@example
829gcc-mingw-core, mingw-runtime, mingw-zlib
830@end example
831
832and add some special flags to your configure invocation.
833
834For a static build run
835@example
836./configure --target-os=mingw32 --enable-memalign-hack --enable-static --disable-shared --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
837@end example
838
839and for a build with shared libraries
840@example
841./configure --target-os=mingw32 --enable-memalign-hack --enable-shared --disable-static --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
842@end example
843
844@section BeOS
845
5f757b85 846BeOS support is broken in mysterious ways.
d0e1cd3d 847
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848@section OS/2
849
850For information about compiling FFmpeg on OS/2 see
851@url{http://www.edm2.com/index.php/FFmpeg}.
852
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853@chapter Developers Guide
854
855@section API
856@itemize @bullet
857@item libavcodec is the library containing the codecs (both encoding and
858decoding). Look at @file{libavcodec/apiexample.c} to see how to use it.
859
860@item libavformat is the library containing the file format handling (mux and
861demux code for several formats). Look at @file{ffplay.c} to use it in a
862player. See @file{output_example.c} to use it to generate audio or video
863streams.
864
865@end itemize
866
867@section Integrating libavcodec or libavformat in your program
868
869You can integrate all the source code of the libraries to link them
870statically to avoid any version problem. All you need is to provide a
871'config.mak' and a 'config.h' in the parent directory. See the defines
872generated by ./configure to understand what is needed.
873
874You can use libavcodec or libavformat in your commercial program, but
875@emph{any patch you make must be published}. The best way to proceed is
876to send your patches to the FFmpeg mailing list.
877
878@node Coding Rules
879@section Coding Rules
880
881FFmpeg is programmed in the ISO C90 language with a few additional
882features from ISO C99, namely:
883@itemize @bullet
884@item
885the @samp{inline} keyword;
886@item
887@samp{//} comments;
888@item
889designated struct initializers (@samp{struct s x = @{ .i = 17 @};})
890@item
891compound literals (@samp{x = (struct s) @{ 17, 23 @};})
892@end itemize
893
894These features are supported by all compilers we care about, so we will not
895accept patches to remove their use unless they absolutely do not impair
896clarity and performance.
897
898All code must compile with GCC 2.95 and GCC 3.3. Currently, FFmpeg also
899compiles with several other compilers, such as the Compaq ccc compiler
900or Sun Studio 9, and we would like to keep it that way unless it would
901be exceedingly involved. To ensure compatibility, please do not use any
902additional C99 features or GCC extensions. Especially watch out for:
903@itemize @bullet
904@item
905mixing statements and declarations;
906@item
907@samp{long long} (use @samp{int64_t} instead);
908@item
909@samp{__attribute__} not protected by @samp{#ifdef __GNUC__} or similar;
910@item
911GCC statement expressions (@samp{(x = (@{ int y = 4; y; @})}).
912@end itemize
913
914Indent size is 4.
915The presentation is the one specified by 'indent -i4 -kr -nut'.
916The TAB character is forbidden outside of Makefiles as is any
917form of trailing whitespace. Commits containing either will be
918rejected by the Subversion repository.
919
920The main priority in FFmpeg is simplicity and small code size in order to
921minimize the bug count.
922
923Comments: Use the JavaDoc/Doxygen
924format (see examples below) so that code documentation
925can be generated automatically. All nontrivial functions should have a comment
926above them explaining what the function does, even if it is just one sentence.
927All structures and their member variables should be documented, too.
928@example
929/**
930 * @@file mpeg.c
931 * MPEG codec.
932 * @@author ...
933 */
934
935/**
936 * Summary sentence.
937 * more text ...
938 * ...
939 */
940typedef struct Foobar@{
941 int var1; /**< var1 description */
942 int var2; ///< var2 description
943 /** var3 description */
944 int var3;
945@} Foobar;
946
947/**
948 * Summary sentence.
949 * more text ...
950 * ...
951 * @@param my_parameter description of my_parameter
952 * @@return return value description
953 */
954int myfunc(int my_parameter)
955...
956@end example
957
958fprintf and printf are forbidden in libavformat and libavcodec,
959please use av_log() instead.
960
961Casts should be used only when necessary. Unneeded parentheses
962should also be avoided if they don't make the code easier to understand.
963
964@section Development Policy
965
966@enumerate
967@item
968 Contributions should be licensed under the LGPL 2.1, including an
969 "or any later version" clause, or the MIT license. GPL 2 including
970 an "or any later version" clause is also acceptable, but LGPL is
971 preferred.
972@item
973 You must not commit code which breaks FFmpeg! (Meaning unfinished but
974 enabled code which breaks compilation or compiles but does not work or
975 breaks the regression tests)
976 You can commit unfinished stuff (for testing etc), but it must be disabled
977 (#ifdef etc) by default so it does not interfere with other developers'
978 work.
979@item
980 You do not have to over-test things. If it works for you, and you think it
981 should work for others, then commit. If your code has problems
982 (portability, triggers compiler bugs, unusual environment etc) they will be
983 reported and eventually fixed.
984@item
985 Do not commit unrelated changes together, split them into self-contained
986 pieces. Also do not forget that if part B depends on part A, but A does not
987 depend on B, then A can and should be committed first and separate from B.
988 Keeping changes well split into self-contained parts makes reviewing and
989 understanding them on the commit log mailing list easier. This also helps
990 in case of debugging later on.
991 Also if you have doubts about splitting or not splitting, do not hesitate to
992 ask/discuss it on the developer mailing list.
993@item
994 Do not change behavior of the program (renaming options etc) without
995 first discussing it on the ffmpeg-devel mailing list. Do not remove
996 functionality from the code. Just improve!
997
998 Note: Redundant code can be removed.
999@item
1000 Do not commit changes to the build system (Makefiles, configure script)
1001 which change behavior, defaults etc, without asking first. The same
1002 applies to compiler warning fixes, trivial looking fixes and to code
1003 maintained by other developers. We usually have a reason for doing things
1004 the way we do. Send your changes as patches to the ffmpeg-devel mailing
1005 list, and if the code maintainers say OK, you may commit. This does not
1006 apply to files you wrote and/or maintain.
1007@item
1008 We refuse source indentation and other cosmetic changes if they are mixed
1009 with functional changes, such commits will be rejected and removed. Every
1010 developer has his own indentation style, you should not change it. Of course
1011 if you (re)write something, you can use your own style, even though we would
1012 prefer if the indentation throughout FFmpeg was consistent (Many projects
1013 force a given indentation style - we do not.). If you really need to make
1014 indentation changes (try to avoid this), separate them strictly from real
1015 changes.
1016
1017 NOTE: If you had to put if()@{ .. @} over a large (> 5 lines) chunk of code,
1018 then either do NOT change the indentation of the inner part within (do not
1019 move it to the right)! or do so in a separate commit
1020@item
1021 Always fill out the commit log message. Describe in a few lines what you
1022 changed and why. You can refer to mailing list postings if you fix a
1023 particular bug. Comments such as "fixed!" or "Changed it." are unacceptable.
1024@item
1025 If you apply a patch by someone else, include the name and email address in
1026 the log message. Since the ffmpeg-cvslog mailing list is publicly
1027 archived you should add some SPAM protection to the email address. Send an
1028 answer to ffmpeg-devel (or wherever you got the patch from) saying that
1029 you applied the patch.
1030@item
1031 When applying patches that have been discussed (at length) on the mailing
1032 list, reference the thread in the log message.
1033@item
1034 Do NOT commit to code actively maintained by others without permission.
1035 Send a patch to ffmpeg-devel instead. If no one answers within a reasonable
1036 timeframe (12h for build failures and security fixes, 3 days small changes,
1037 1 week for big patches) then commit your patch if you think it is OK.
1038 Also note, the maintainer can simply ask for more time to review!
1039@item
1040 Subscribe to the ffmpeg-cvslog mailing list. The diffs of all commits
1041 are sent there and reviewed by all the other developers. Bugs and possible
1042 improvements or general questions regarding commits are discussed there. We
1043 expect you to react if problems with your code are uncovered.
1044@item
1045 Update the documentation if you change behavior or add features. If you are
1046 unsure how best to do this, send a patch to ffmpeg-devel, the documentation
1047 maintainer(s) will review and commit your stuff.
1048@item
1049 Try to keep important discussions and requests (also) on the public
1050 developer mailing list, so that all developers can benefit from them.
1051@item
1052 Never write to unallocated memory, never write over the end of arrays,
1053 always check values read from some untrusted source before using them
1054 as array index or other risky things.
1055@item
1056 Remember to check if you need to bump versions for the specific libav
1057 parts (libavutil, libavcodec, libavformat) you are changing. You need
b98052d5 1058 to change the version integer.
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1059 Incrementing the first component means no backward compatibility to
1060 previous versions (e.g. removal of a function from the public API).
1061 Incrementing the second component means backward compatible change
b98052d5
PR
1062 (e.g. addition of a function to the public API or extension of an
1063 existing data structure).
d0e1cd3d
DB
1064 Incrementing the third component means a noteworthy binary compatible
1065 change (e.g. encoder bug fix that matters for the decoder).
1066@item
53407b64 1067 Compiler warnings indicate potential bugs or code with bad style. If a type of
9908c1a8
DB
1068 warning always points to correct and clean code, that warning should
1069 be disabled, not the code changed.
1070 Thus the remaining warnings can either be bugs or correct code.
beaa4a91 1071 If it is a bug, the bug has to be fixed. If it is not, the code should
9908c1a8
DB
1072 be changed to not generate a warning unless that causes a slowdown
1073 or obfuscates the code.
d0e1cd3d
DB
1074@item
1075 If you add a new file, give it a proper license header. Do not copy and
1076 paste it from a random place, use an existing file as template.
1077@end enumerate
1078
1079We think our rules are not too hard. If you have comments, contact us.
1080
1081Note, these rules are mostly borrowed from the MPlayer project.
1082
1083@section Submitting patches
1084
1085First, (@pxref{Coding Rules}) above if you did not yet.
1086
1087When you submit your patch, try to send a unified diff (diff '-up'
1088option). We cannot read other diffs :-)
1089
1090Also please do not submit a patch which contains several unrelated changes.
1091Split it into separate, self-contained pieces. This does not mean splitting
1092file by file. Instead, make the patch as small as possible while still
1093keeping it as a logical unit that contains an individual change, even
1094if it spans multiple files. This makes reviewing your patches much easier
1095for us and greatly increases your chances of getting your patch applied.
1096
1097Run the regression tests before submitting a patch so that you can
1098verify that there are no big problems.
1099
1100Patches should be posted as base64 encoded attachments (or any other
1101encoding which ensures that the patch will not be trashed during
1102transmission) to the ffmpeg-devel mailing list, see
1103@url{http://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel}
1104
1105It also helps quite a bit if you tell us what the patch does (for example
1106'replaces lrint by lrintf'), and why (for example '*BSD isn't C99 compliant
1107and has no lrint()')
1108
1109Also please if you send several patches, send each patch as a separate mail,
1110do not attach several unrelated patches to the same mail.
1111
28ce1839
RP
1112@section New codecs or formats checklist
1113
1114@enumerate
1115@item
1116 Did you use av_cold for codec initialization and close functions?
1117@item
1118 Did you add a long_name under NULL_IF_CONFIG_SMALL to the AVCodec or
1119 AVInputFormat/AVOutputFormat struct?
1120@item
1121 Did you bump the minor version number in @file{avcodec.h} or
1122 @file{avformat.h}?
1123@item
1124 Did you register it in @file{allcodecs.c} or @file{allformats.c}?
1125@item
1126 Did you add the CodecID to @file{avcodec.h}?
1127@item
1128 If it has a fourcc, did you add it to @file{libavformat/riff.c},
1129 even if it is only a decoder?
1130@item
1131 Did you add a rule to compile the appropriate files in the Makefile?
1132 Remember to do this even if you're just adding a format to a file that is
1133 already being compiled by some other rule, like a raw demuxer.
1134@item
1135 Did you add an entry to the table of supported formats or codecs in the
1136 documentation?
1137@item
1138 Did you add an entry in the Changelog?
1139@item
1140 If it depends on a parser or a library, did you add that dependency in
1141 configure?
1142@item
1143 Did you "svn add" the appropriate files before commiting?
1144@end enumerate
1145
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1146@section patch submission checklist
1147
1148@enumerate
1149@item
1150 Do the regression tests pass with the patch applied?
1151@item
2cdba8bf
DB
1152 Does @code{make checkheaders} pass with the patch applied?
1153@item
d0e1cd3d
DB
1154 Is the patch a unified diff?
1155@item
1156 Is the patch against latest FFmpeg SVN?
1157@item
1158 Are you subscribed to ffmpeg-dev?
1159 (the list is subscribers only due to spam)
1160@item
1161 Have you checked that the changes are minimal, so that the same cannot be
1162 achieved with a smaller patch and/or simpler final code?
1163@item
1164 If the change is to speed critical code, did you benchmark it?
1165@item
1166 If you did any benchmarks, did you provide them in the mail?
1167@item
1168 Have you checked that the patch does not introduce buffer overflows or
1169 other security issues?
1170@item
63d247ea
DB
1171 Did you test your decoder or demuxer against damaged data? If no, see
1172 tools/trasher and the noise bitstream filter. Your decoder or demuxer
1173 should not crash or end in a (near) infinite loop when fed damaged data.
b885e0db 1174@item
d0e1cd3d
DB
1175 Is the patch created from the root of the source tree, so it can be
1176 applied with @code{patch -p0}?
1177@item
1178 Does the patch not mix functional and cosmetic changes?
1179@item
1180 Did you add tabs or trailing whitespace to the code? Both are forbidden.
1181@item
1182 Is the patch attached to the email you send?
1183@item
1184 Is the mime type of the patch correct? It should be text/x-diff or
1185 text/x-patch or at least text/plain and not application/octet-stream.
1186@item
1187 If the patch fixes a bug, did you provide a verbose analysis of the bug?
1188@item
1189 If the patch fixes a bug, did you provide enough information, including
1190 a sample, so the bug can be reproduced and the fix can be verified?
1191 Note please do not attach samples >100k to mails but rather provide a
0fa5f24c 1192 URL, you can upload to ftp://upload.ffmpeg.org
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1193@item
1194 Did you provide a verbose summary about what the patch does change?
1195@item
1196 Did you provide a verbose explanation why it changes things like it does?
1197@item
1198 Did you provide a verbose summary of the user visible advantages and
1199 disadvantages if the patch is applied?
1200@item
1201 Did you provide an example so we can verify the new feature added by the
1202 patch easily?
1203@item
1204 If you added a new file, did you insert a license header? It should be
1205 taken from FFmpeg, not randomly copied and pasted from somewhere else.
1206@item
1207 You should maintain alphabetical order in alphabetically ordered lists as
1208 long as doing so does not break API/ABI compatibility.
1209@item
1210 Lines with similar content should be aligned vertically when doing so
1211 improves readability.
1212@item
1213 Did you provide a suggestion for a clear commit log message?
1214@end enumerate
1215
1216@section Patch review process
1217
1218All patches posted to ffmpeg-devel will be reviewed, unless they contain a
1219clear note that the patch is not for SVN.
1220Reviews and comments will be posted as replies to the patch on the
1221mailing list. The patch submitter then has to take care of every comment,
1222that can be by resubmitting a changed patch or by discussion. Resubmitted
1223patches will themselves be reviewed like any other patch. If at some point
1224a patch passes review with no comments then it is approved, that can for
1225simple and small patches happen immediately while large patches will generally
1226have to be changed and reviewed many times before they are approved.
1227After a patch is approved it will be committed to the repository.
1228
1229We will review all submitted patches, but sometimes we are quite busy so
1230especially for large patches this can take several weeks.
1231
1232When resubmitting patches, please do not make any significant changes
1233not related to the comments received during review. Such patches will
1234be rejected. Instead, submit significant changes or new features as
1235separate patches.
1236
1237@section Regression tests
1238
1239Before submitting a patch (or committing to the repository), you should at least
1240test that you did not break anything.
1241
1242The regression tests build a synthetic video stream and a synthetic
1243audio stream. These are then encoded and decoded with all codecs or
1244formats. The CRC (or MD5) of each generated file is recorded in a
1245result file. A 'diff' is launched to compare the reference results and
1246the result file.
1247
1248The regression tests then go on to test the FFserver code with a
1249limited set of streams. It is important that this step runs correctly
1250as well.
1251
1252Run 'make test' to test all the codecs and formats.
1253
1254Run 'make fulltest' to test all the codecs, formats and FFserver.
1255
1256[Of course, some patches may change the results of the regression tests. In
1257this case, the reference results of the regression tests shall be modified
1258accordingly].
1259
1260@bye