Revert r15653.
[libav.git] / doc / general.texi
CommitLineData
d0e1cd3d
DB
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
50e4d833
DB
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.
d0e1cd3d
DB
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
68e7d442
DB
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
d0e1cd3d
DB
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
DB
45 @tab 4X Technologies format, used in some games.
46@item ADTS AAC audio @tab X @tab X
64c2f20a
DB
47@item American Laser Games MM @tab @tab X
48 @tab Multimedia format used in games like Mad Dog McCree.
c6b2dc34
DB
49@item ASF @tab X @tab X
50@item AVI @tab X @tab X
51@item AVM2 (Flash 9) @tab X @tab X
d698c5d3 52 @tab Only embedded audio is decoded.
c6b2dc34 53@item AVS @tab @tab X
d698c5d3 54 @tab Multimedia format used by the Creature Shock game.
c6b2dc34 55@item Bethsoft VID @tab @tab X
d698c5d3 56 @tab Used in some games from Bethesda Softworks.
64c2f20a
DB
57@item BFI @tab @tab X
58 @tab Brute Force & Ignorance, used in Flash Traffic: City of Angels.
c6b2dc34 59@item C93 @tab @tab X
d698c5d3 60 @tab Used in the game Cyberia from Interplay.
c6b2dc34 61@item CIN @tab @tab X
d698c5d3 62 @tab Multimedia format used by Delphine Software games.
c6b2dc34 63@item Creative VOC @tab X @tab X
d698c5d3 64 @tab Created for the Sound Blaster Pro.
64c2f20a
DB
65@item CRYO APC @tab @tab X
66 @tab Audio format used in some games by CRYO Interactive Entertainment.
c6b2dc34
DB
67@item DV @tab X @tab X
68@item DXA @tab @tab X
d698c5d3
DB
69 @tab This format is used in the non-Windows version of the Feeble Files
70 game and different game cutscenes repacked for use with ScummVM.
c6b2dc34 71@item Electronic Arts Multimedia @tab @tab X
d698c5d3 72 @tab Used in various EA games; files have extensions like WVE and UV2.
c6b2dc34 73@item FLIC @tab @tab X
d698c5d3 74 @tab .fli/.flc files
c6b2dc34 75@item FLV @tab X @tab X
d698c5d3 76 @tab Macromedia Flash video files
c6b2dc34 77@item GXF @tab X @tab X
d698c5d3 78 @tab General eXchange Format SMPTE 360M, used by Thomson Grass Valley
64c2f20a 79 playout servers.
76ec3939 80@item id Cinematic @tab @tab X
d698c5d3 81 @tab Used in Quake II.
76ec3939 82@item id RoQ @tab X @tab X
d698c5d3 83 @tab Used in Quake III, Jedi Knight 2, other computer games.
c6b2dc34 84@item IFF @tab @tab X
d698c5d3 85 @tab Interchange File Format
c6b2dc34 86@item Interplay MVE @tab @tab X
d698c5d3 87 @tab Format used in various Interplay computer games.
c6b2dc34 88@item LMLM4 @tab @tab X
d698c5d3 89 @tab Used by Linux Media Labs MPEG-4 PCI boards
64c2f20a 90@item Matroska @tab X @tab X
c6b2dc34 91@item MAXIS EA XA @tab @tab X
d698c5d3 92 @tab Used in Sim City 3000; file extension .xa.
64c2f20a 93@item Monkey's Audio @tab @tab X
822cc8f7 94@item Motion Pixels MVI @tab @tab X
64c2f20a 95@item MOV/QuickTime @tab X @tab X
c6b2dc34
DB
96@item MPEG audio @tab X @tab X
97@item MPEG-1 systems @tab X @tab X
d698c5d3 98 @tab muxed audio and video
c6b2dc34 99@item MPEG-2 PS @tab X @tab X
d698c5d3 100 @tab also known as @code{VOB} file
c6b2dc34 101@item MPEG-2 TS @tab @tab X
d698c5d3 102 @tab also known as DVB Transport Stream
c6b2dc34 103@item MPEG-4 @tab X @tab X
d698c5d3 104 @tab MPEG-4 is a variant of QuickTime.
bac4c85c 105@item MSN TCP webcam @tab @tab X
d698c5d3 106 @tab Used by MSN Messenger webcam streams.
bb68b69d 107@item MXF @tab X @tab X
d698c5d3 108 @tab Material eXchange Format SMPTE 377M, used by D-Cinema, broadcast industry.
64c2f20a 109@item Nullsoft Video @tab @tab X
c6b2dc34 110@item NUT @tab X @tab X
d698c5d3 111 @tab NUT Open Container Format
c6b2dc34 112@item OMA @tab @tab X
d698c5d3 113 @tab Audio format used in Sony Sonic Stage and Sony Vegas.
64c2f20a 114@item PlayStation STR @tab @tab X
c6b2dc34 115@item PVA @tab @tab X
d698c5d3 116 @tab Used by TechnoTrend DVB PCI boards.
76ec3939
DB
117@item raw AC-3 @tab X @tab X
118@item raw CRI ADX audio @tab X @tab X
119@item raw MJPEG @tab X @tab X
120@item raw MPEG video @tab X @tab X
121@item raw MPEG-4 video @tab X @tab X
eb6fc557 122@item raw PCM 8/16/32 bits, 32/64-bit floating point, mu-law/A-law @tab X @tab X
76ec3939 123@item raw Shorten audio @tab @tab X
64c2f20a 124@item RealMedia @tab X @tab X
c6b2dc34 125@item RL2 @tab @tab X
d698c5d3 126 @tab Audio and video format used in some games by Entertainment Software Partners.
c6b2dc34 127@item Sega FILM/CPK @tab @tab X
d698c5d3 128 @tab Used in many Sega Saturn console games.
64c2f20a
DB
129@item SEQ @tab @tab X
130 @tab Tiertex .seq files used in the DOS CD-ROM version of the game Flashback.
c6b2dc34 131@item Sierra Online @tab @tab X
d698c5d3 132 @tab .sol files used in Sierra Online games.
c6b2dc34 133@item Sierra VMD @tab @tab X
d698c5d3 134 @tab Used in Sierra CD-ROM games.
64c2f20a
DB
135@item SIFF @tab @tab X
136 @tab Audio and video format used in some games by Beam Software.
c6b2dc34 137@item Smacker @tab @tab X
d698c5d3 138 @tab Multimedia format used by many games.
64c2f20a 139@item SUN AU format @tab X @tab X
c6b2dc34 140@item THP @tab @tab X
d698c5d3 141 @tab Used on the Nintendo GameCube.
c6b2dc34
DB
142@item WAV @tab X @tab X
143@item WC3 Movie @tab @tab X
d698c5d3 144 @tab Multimedia format used in Origin's Wing Commander III computer game.
c6b2dc34 145@item Westwood Studios VQA/AUD @tab @tab X
d698c5d3 146 @tab Multimedia formats used in Westwood Studios games.
d0e1cd3d
DB
147@end multitable
148
149@code{X} means that encoding (resp. decoding) is supported.
150
151@section Image Formats
152
153FFmpeg can read and write images for each frame of a video sequence. The
154following image formats are supported:
155
156@multitable @columnfractions .4 .1 .1 .4
b3de4544 157@item Name @tab Encoding @tab Decoding @tab Comments
64c2f20a 158@item .Y.U.V @tab X @tab X @tab one raw file per component
3d172fb5
DB
159@item animated GIF @tab X @tab X @tab Only uncompressed GIFs are generated.
160@item JPEG @tab X @tab X @tab Progressive JPEG is not supported.
d0e1cd3d 161@item PAM @tab X @tab X @tab PAM is a PNM extension with alpha support.
3d172fb5
DB
162@item PCX @tab @tab X @tab PC Paintbrush
163@item PGM, PPM @tab X @tab X
d0e1cd3d 164@item PGMYUV @tab X @tab X @tab PGM with U and V components in YUV 4:2:0
0a91f4ee 165@item PNG @tab X @tab X @tab 2/4 bpp not supported yet
d0e1cd3d 166@item PTX @tab @tab X @tab V.Flash PTX format
d1928ac1 167@item RAS @tab @tab X @tab Sun Rasterfile
3d172fb5 168@item SGI @tab X @tab X @tab SGI RGB image format
3d172fb5 169@item Targa @tab @tab X @tab Targa (.TGA) image format
64c2f20a 170@item TIFF @tab X @tab X @tab YUV, JPEG and some extension is not supported yet.
d0e1cd3d
DB
171@end multitable
172
173@code{X} means that encoding (resp. decoding) is supported.
174
175@section Video Codecs
176
177@multitable @columnfractions .4 .1 .1 .4
b3de4544 178@item Name @tab Encoding @tab Decoding @tab Comments
d66d8b83 179@item 4X Video @tab @tab X
d698c5d3 180 @tab Used in certain computer games.
d66d8b83 181@item American Laser Games Video @tab @tab X
d698c5d3 182 @tab Used in games like Mad Dog McCree.
d66d8b83 183@item AMV @tab @tab X
d698c5d3 184 @tab Used in Chinese MP3 players.
d66d8b83 185@item Apple Animation @tab X @tab X
d698c5d3 186 @tab fourcc: 'rle '
d66d8b83 187@item Apple Graphics @tab @tab X
d698c5d3 188 @tab fourcc: 'smc '
d66d8b83
DB
189@item Apple MJPEG-B @tab @tab X
190@item Apple QuickDraw @tab @tab X
d698c5d3 191 @tab fourcc: qdrw
d66d8b83 192@item Apple Video @tab @tab X
d698c5d3 193 @tab fourcc: rpza
d66d8b83 194@item Asus v1 @tab X @tab X
d698c5d3 195 @tab fourcc: ASV1
d66d8b83 196@item Asus v2 @tab X @tab X
d698c5d3 197 @tab fourcc: ASV2
d66d8b83 198@item ATI VCR1 @tab @tab X
d698c5d3 199 @tab fourcc: VCR1
d66d8b83 200@item ATI VCR2 @tab @tab X
d698c5d3 201 @tab fourcc: VCR2
d66d8b83 202@item Autodesk RLE @tab @tab X
d698c5d3 203 @tab fourcc: AASC
d66d8b83 204@item AVID DNxHD @tab X @tab X
d698c5d3 205 @tab aka SMPTE VC3
bac4c85c 206@item AVS video @tab @tab X
d698c5d3 207 @tab Video encoding used by the Creature Shock game.
d66d8b83 208@item Bethsoft VID @tab @tab X
d698c5d3 209 @tab Used in some games from Bethesda Softworks.
bac4c85c 210@item C93 video @tab @tab X
d698c5d3 211 @tab Codec used in Cyberia game.
d66d8b83 212@item CamStudio @tab @tab X
d698c5d3 213 @tab fourcc: CSCD
bac4c85c 214@item Cin video @tab @tab X
d698c5d3 215 @tab Codec used in Delphine Software games.
d66d8b83
DB
216@item Cinepak @tab @tab X
217@item Cirrus Logic AccuPak @tab @tab X
d698c5d3 218 @tab fourcc: CLJR
d66d8b83 219@item Creative YUV @tab @tab X
d698c5d3 220 @tab fourcc: CYUV
5c5a6dfe
DB
221@item Dirac @tab X @tab X
222 @tab Supported through the external libdirac/libschroedinger libraries.
d66d8b83 223@item Duck TrueMotion v1 @tab @tab X
d698c5d3 224 @tab fourcc: DUCK
d66d8b83 225@item Duck TrueMotion v2 @tab @tab X
d698c5d3 226 @tab fourcc: TM20
d66d8b83
DB
227@item DV @tab X @tab X
228@item DXA Video @tab @tab X
d698c5d3 229 @tab Codec originally used in Feeble Files game.
d66d8b83 230@item Electronic Arts CMV @tab @tab X
d698c5d3 231 @tab Used in NHL 95 game.
cfc78718 232@item Electronic Arts TGV @tab @tab X
d66d8b83 233@item FFmpeg Video 1 @tab X @tab X
d698c5d3 234 @tab experimental lossless codec (fourcc: FFV1)
d66d8b83 235@item Flash Screen Video @tab X @tab X
d698c5d3 236 @tab fourcc: FSV1
d66d8b83
DB
237@item FLIC video @tab @tab X
238@item FLV @tab X @tab X
d698c5d3 239 @tab Sorenson H.263 used in Flash
d66d8b83
DB
240@item Fraps FPS1 @tab @tab X
241@item H.261 @tab X @tab X
242@item H.263(+) @tab X @tab X
d698c5d3 243 @tab also known as RealVideo 1.0
d66d8b83
DB
244@item H.264 @tab @tab X
245@item HuffYUV @tab X @tab X
246@item IBM Ultimotion @tab @tab X
d698c5d3 247 @tab fourcc: ULTI
bac4c85c 248@item id Cinematic video @tab @tab X
d698c5d3 249 @tab Used in Quake II.
d66d8b83 250@item id RoQ @tab X @tab X
d698c5d3 251 @tab Used in Quake III, Jedi Knight 2, other computer games.
d66d8b83
DB
252@item Intel Indeo 3 @tab @tab X
253@item Interplay Video @tab @tab X
d698c5d3 254 @tab Used in Interplay .MVE files.
d66d8b83 255@item JPEG-LS @tab X @tab X
d698c5d3 256 @tab fourcc: MJLS, lossless and near-lossless is supported.
d66d8b83 257@item KMVC @tab @tab X
d698c5d3 258 @tab Codec used in Worms games.
d66d8b83
DB
259@item LOCO @tab @tab X
260@item lossless MJPEG @tab X @tab X
261@item Microsoft RLE @tab @tab X
262@item Microsoft Video-1 @tab @tab X
263@item Mimic @tab @tab X
d698c5d3 264 @tab Used in MSN Messenger Webcam streams.
d66d8b83 265@item Miro VideoXL @tab @tab X
d698c5d3 266 @tab fourcc: VIXL
d66d8b83 267@item MJPEG @tab X @tab X
822cc8f7 268@item Motion Pixels Video @tab @tab X
bac4c85c
DB
269@item MPEG-1 @tab X @tab X
270@item MPEG-2 @tab X @tab X
d0e1cd3d
DB
271@item MPEG-4 @tab X @tab X
272@item MSMPEG4 V1 @tab X @tab X
273@item MSMPEG4 V2 @tab X @tab X
274@item MSMPEG4 V3 @tab X @tab X
d66d8b83 275@item MSZH @tab @tab X
d698c5d3 276 @tab Part of LCL
d66d8b83 277@item On2 VP3 @tab @tab X
d698c5d3 278 @tab still experimental
d66d8b83 279@item On2 VP5 @tab @tab X
d698c5d3 280 @tab fourcc: VP50
d66d8b83 281@item On2 VP6 @tab @tab X
d698c5d3 282 @tab fourcc: VP60,VP61,VP62
d66d8b83 283@item planar RGB @tab @tab X
d698c5d3 284 @tab fourcc: 8BPS
d66d8b83 285@item QPEG @tab @tab X
d698c5d3 286 @tab fourccs: QPEG, Q1.0, Q1.1
d0e1cd3d
DB
287@item RealVideo 1.0 @tab X @tab X
288@item RealVideo 2.0 @tab X @tab X
d66d8b83 289@item Renderware TXD @tab @tab X
d698c5d3 290 @tab Texture dictionaries used by the Renderware Engine.
d66d8b83 291@item RTjpeg @tab @tab X
d698c5d3 292 @tab Video encoding used in NuppelVideo files.
bac4c85c 293@item Smacker video @tab @tab X
d698c5d3 294 @tab Video encoding used in Smacker.
d66d8b83 295@item Snow @tab X @tab X
d698c5d3 296 @tab experimental wavelet codec (fourcc: SNOW)
831ec935 297@item Sony PlayStation MDEC @tab @tab X
d66d8b83 298@item Sorenson Video 1 @tab X @tab X
d698c5d3 299 @tab fourcc: SVQ1
d66d8b83 300@item Sorenson Video 3 @tab @tab X
d698c5d3 301 @tab fourcc: SVQ3
d66d8b83 302@item Sunplus MJPEG @tab @tab X
d698c5d3 303 @tab fourcc: SP5X
d66d8b83 304@item TechSmith Camtasia @tab @tab X
d698c5d3 305 @tab fourcc: TSCC
d66d8b83 306@item Theora @tab X @tab X
d698c5d3 307 @tab still experimental
d66d8b83 308@item THP @tab @tab X
d698c5d3 309 @tab Used on the Nintendo GameCube.
bac4c85c 310@item Tiertex Seq video @tab @tab X
d698c5d3 311 @tab Codec used in DOS CD-ROM FlashBack game.
d66d8b83
DB
312@item VC-1 @tab @tab X
313@item VMD Video @tab @tab X
d698c5d3 314 @tab Used in Sierra VMD files.
d66d8b83 315@item VMware Video @tab @tab X
d698c5d3 316 @tab Codec used in videos captured by VMware.
d0e1cd3d 317@item Westwood VQA @tab @tab X
d66d8b83
DB
318@item Winnov WNV1 @tab @tab X
319@item WMV7 @tab X @tab X
320@item WMV8 @tab X @tab X
321@item WMV9 @tab @tab X
d698c5d3 322 @tab not completely working
d66d8b83 323@item Xan/WC3 @tab @tab X
d698c5d3 324 @tab Used in Wing Commander III .MVE files.
d66d8b83 325@item ZLIB @tab X @tab X
d698c5d3 326 @tab part of LCL, encoder experimental
d66d8b83 327@item ZMBV @tab X @tab X
d698c5d3 328 @tab Encoder works only in PAL8.
d0e1cd3d
DB
329@end multitable
330
331@code{X} means that encoding (resp. decoding) is supported.
332
333@section Audio Codecs
334
335@multitable @columnfractions .4 .1 .1 .1 .7
b3de4544 336@item Name @tab Encoding @tab Decoding @tab Comments
16d81b27
DB
337@item 4X IMA ADPCM @tab @tab X
338@item 8SVX audio @tab @tab X
339@item AAC @tab X @tab X
7d8f3de4 340 @tab Encoding is supported through the external library libfaac.
16d81b27 341@item AC-3 @tab IX @tab IX
16d81b27 342@item AMR-NB @tab X @tab X
d698c5d3 343 @tab Supported through an external library.
16d81b27 344@item AMR-WB @tab X @tab X
d698c5d3 345 @tab Supported through an external library.
16d81b27 346@item AMV IMA ADPCM @tab @tab X
d698c5d3 347 @tab Used in AMV files
833e90dd 348@item Apple lossless audio @tab X @tab X
d698c5d3 349 @tab QuickTime fourcc 'alac'
16d81b27
DB
350@item Apple MACE 3 @tab @tab X
351@item Apple MACE 6 @tab @tab X
352@item ATRAC 3 @tab @tab X
353@item CD-ROM XA ADPCM @tab @tab X
bac4c85c 354@item Cin audio @tab @tab X
d698c5d3 355 @tab Codec used in Delphine Software International games.
16d81b27 356@item Creative ADPCM @tab @tab X
d698c5d3 357 @tab 16 -> 4, 8 -> 4, 8 -> 3, 8 -> 2
16d81b27 358@item CRI ADX ADPCM @tab X @tab X
d698c5d3 359 @tab Used in Sega Dreamcast games.
16d81b27
DB
360@item DSP Group TrueSpeech @tab @tab X
361@item DTS Coherent Audio @tab @tab X
362@item Duck DK3 IMA ADPCM @tab @tab X
d698c5d3 363 @tab Used in some Sega Saturn console games.
16d81b27 364@item Duck DK4 IMA ADPCM @tab @tab X
d698c5d3 365 @tab Used in some Sega Saturn console games.
16d81b27
DB
366@item DV audio @tab @tab X
367@item Electronic Arts ADPCM @tab @tab X
d698c5d3 368 @tab Used in various EA titles.
44723c84 369@item Enhanced AC-3 @tab @tab X
9a584db4 370@item FLAC lossless audio @tab IX @tab X
16d81b27
DB
371@item G.726 ADPCM @tab X @tab X
372@item id RoQ DPCM @tab X @tab X
d698c5d3 373 @tab Used in Quake III, Jedi Knight 2, other computer games.
16d81b27
DB
374@item Intel Music Coder @tab @tab X
375@item Interplay MVE DPCM @tab @tab X
d698c5d3 376 @tab Used in various Interplay computer games.
16d81b27 377@item MAXIS EA ADPCM @tab @tab X
d698c5d3 378 @tab Used in Sim City 3000.
16d81b27
DB
379@item Microsoft ADPCM @tab X @tab X
380@item MLP/TrueHD @tab @tab X
d698c5d3 381 @tab Used in DVD-Audio and Blu-Ray discs.
16d81b27 382@item Monkey's Audio @tab @tab X
d698c5d3 383 @tab Only versions 3.97-3.99 are supported.
16d81b27 384@item MPEG audio layer 1/3 @tab X @tab IX
d698c5d3 385 @tab MP3 encoding is supported through the external library LAME.
16d81b27
DB
386@item MPEG audio layer 2 @tab IX @tab IX
387@item MS IMA ADPCM @tab X @tab X
388@item Musepack @tab @tab X
d698c5d3 389 @tab SV7 and SV8 are supported.
755ba886 390@item Nellymoser ASAO @tab X @tab X
16d81b27 391@item Qdesign QDM2 @tab @tab X
d698c5d3 392 @tab There are still some distortions.
16d81b27
DB
393@item QT IMA ADPCM @tab X @tab X
394@item RA144 @tab @tab X
d698c5d3 395 @tab Real 14400 bit/s codec
16d81b27 396@item RA288 @tab @tab X
d698c5d3 397 @tab Real 28800 bit/s codec
575a5bf2 398@item RADnet @tab IX @tab IX
a692130f 399 @tab Real low bitrate AC-3 codec
16d81b27 400@item Real COOK @tab @tab X
d698c5d3 401 @tab All versions except 5.1 are supported.
bac4c85c 402@item Shorten @tab @tab X
16d81b27 403@item Sierra Online DPCM @tab @tab X
d698c5d3 404 @tab Used in Sierra Online game audio files.
bac4c85c 405@item Smacker audio @tab @tab X
16d81b27 406@item SMJPEG IMA ADPCM @tab @tab X
d698c5d3 407 @tab Used in certain Loki game ports.
e6fa1ca5
JR
408@item Sonic @tab X @tab X
409 @tab experimental codec
410@item Sonic lossless @tab X @tab X
411 @tab experimental codec
16d81b27 412@item THP ADPCM @tab @tab X
d698c5d3 413 @tab Used on the Nintendo GameCube.
16d81b27
DB
414@item True Audio (TTA) @tab @tab X
415@item Vorbis @tab X @tab X
bac4c85c 416@item WavPack @tab @tab X
16d81b27 417@item Westwood Studios IMA ADPCM @tab @tab X
d698c5d3 418 @tab Used in Westwood Studios games like Command and Conquer.
bac4c85c 419@item WMA v1/v2 @tab X @tab X
16d81b27 420@item Xan DPCM @tab @tab X
d698c5d3 421 @tab Used in Origin's Wing Commander IV AVI files.
d0e1cd3d
DB
422@end multitable
423
424@code{X} means that encoding (resp. decoding) is supported.
425
426@code{I} means that an integer-only version is available, too (ensures high
427performance on systems without hardware floating point support).
428
429@chapter Platform Specific information
430
431@section BSD
432
433BSD make will not build FFmpeg, you need to install and use GNU Make
434(@file{gmake}).
435
436@section Windows
437
46a845d0 438To get help and instructions for building FFmpeg under Windows, check out
d0e1cd3d 439the FFmpeg Windows Help Forum at
ab5ce4ae 440@url{http://ffmpeg.arrozcru.org/}.
d0e1cd3d
DB
441
442@subsection Native Windows compilation
443
c1989552 444FFmpeg can be built to run natively on Windows using the MinGW tools. Install
126cadc7
RP
445the latest versions of MSYS and MinGW from @url{http://www.mingw.org/}.
446You can find detailed installation
d0e1cd3d
DB
447instructions in the download section and the FAQ.
448
126cadc7
RP
449FFmpeg does not build out-of-the-box with the packages the automated MinGW
450installer provides. It also requires coreutils to be installed and many other
451packages updated to the latest version. The minimum version for some packages
452are listed below:
453
454@itemize
455@item bash 3.1
456@item msys-make 3.81-2 (note: not mingw32-make)
457@item w32api 3.12
458@item mingw-runtime 3.15
459@end itemize
460
c1989552 461Within the MSYS shell, configure and make with:
d0e1cd3d 462
c1989552
RP
463@example
464./configure --enable-memalign-hack
465make
466make install
467@end example
d0e1cd3d 468
c1989552
RP
469This will install @file{ffmpeg.exe} along with many other development files
470to @file{/usr/local}. You may specify another install path using the
471@code{--prefix} option in @file{configure}.
d0e1cd3d 472
c1989552 473Notes:
d0e1cd3d 474
c1989552 475@itemize
d0e1cd3d 476
c1989552
RP
477@item In order to compile vhooks, you must have a POSIX-compliant libdl in
478your MinGW system. Get dlfcn-win32 from
479@url{http://code.google.com/p/dlfcn-win32}.
d0e1cd3d 480
c1989552
RP
481@item In order to compile FFplay, you must have the MinGW development library
482of SDL. Get it from @url{http://www.libsdl.org}.
483Edit the @file{bin/sdl-config} script so that it points to the correct prefix
484where SDL was installed. Verify that @file{sdl-config} can be launched from
485the MSYS command line.
d0e1cd3d 486
d0e1cd3d 487@item By using @code{./configure --enable-shared} when configuring FFmpeg,
c1989552 488you can build libavutil, libavcodec and libavformat as DLLs.
d0e1cd3d
DB
489
490@end itemize
491
c1989552 492@subsection Microsoft Visual C++ compatibility
d0e1cd3d 493
c1989552
RP
494As stated in the FAQ, FFmpeg will not compile under MSVC++. However, if you
495want to use the libav* libraries in your own applications, you can still
496compile those applications using MSVC++. But the libav* libraries you link
497to @emph{must} be built with MinGW. However, you will not be able to debug
498inside the libav* libraries, since MSVC++ does not recognize the debug
499symbols generated by GCC.
500We strongly recommend you to move over from MSVC++ to MinGW tools.
d0e1cd3d 501
c1989552
RP
502This description of how to use the FFmpeg libraries with MSVC++ is based on
503Microsoft Visual C++ 2005 Express Edition. If you have a different version,
504you might have to modify the procedures slightly.
d0e1cd3d 505
c1989552 506@subsubsection Using static libraries
d0e1cd3d 507
c1989552 508Assuming you have just built and installed FFmpeg in @file{/usr/local}.
d0e1cd3d
DB
509
510@enumerate
511
512@item Create a new console application ("File / New / Project") and then
513select "Win32 Console Application". On the appropriate page of the
514Application Wizard, uncheck the "Precompiled headers" option.
515
516@item Write the source code for your application, or, for testing, just
517copy the code from an existing sample application into the source file
c1989552
RP
518that MSVC++ has already created for you. For example, you can copy
519@file{output_example.c} from the FFmpeg distribution.
d0e1cd3d
DB
520
521@item Open the "Project / Properties" dialog box. In the "Configuration"
522combo box, select "All Configurations" so that the changes you make will
523affect both debug and release builds. In the tree view on the left hand
524side, select "C/C++ / General", then edit the "Additional Include
c1989552
RP
525Directories" setting to contain the path where the FFmpeg includes were
526installed (i.e. @file{c:\msys\1.0\local\include}).
f010d377
RP
527Do not add MinGW's include directory here, or the include files will
528conflict with MSVC's.
c1989552
RP
529
530@item Still in the "Project / Properties" dialog box, select
531"Linker / General" from the tree view and edit the
532"Additional Library Directories" setting to contain the @file{lib}
533directory where FFmpeg was installed (i.e. @file{c:\msys\1.0\local\lib}),
534the directory where MinGW libs are installed (i.e. @file{c:\mingw\lib}),
535and the directory where MinGW's GCC libs are installed
536(i.e. @file{C:\mingw\lib\gcc\mingw32\4.2.1-sjlj}). Then select
537"Linker / Input" from the tree view, and add the files @file{libavformat.a},
538@file{libavcodec.a}, @file{libavutil.a}, @file{libmingwex.a},
539@file{libgcc.a}, and any other libraries you used (i.e. @file{libz.a})
540to the end of "Additional Dependencies".
d0e1cd3d
DB
541
542@item Now, select "C/C++ / Code Generation" from the tree view. Select
543"Debug" in the "Configuration" combo box. Make sure that "Runtime
544Library" is set to "Multi-threaded Debug DLL". Then, select "Release" in
545the "Configuration" combo box and make sure that "Runtime Library" is
546set to "Multi-threaded DLL".
547
c1989552
RP
548@item Click "OK" to close the "Project / Properties" dialog box.
549
550@item MSVC++ lacks some C99 header files that are fundamental for FFmpeg.
551Get msinttypes from @url{http://code.google.com/p/msinttypes/downloads/list}
552and install it in MSVC++'s include directory
553(i.e. @file{C:\Program Files\Microsoft Visual Studio 8\VC\include}).
554
555@item MSVC++ also does not understand the @code{inline} keyword used by
556FFmpeg, so you must add this line before @code{#include}ing libav*:
557@example
558#define inline _inline
559@end example
560
c1989552
RP
561@item Build your application, everything should work.
562
563@end enumerate
564
565@subsubsection Using shared libraries
566
567This is how to create DLL and LIB files that are compatible with MSVC++:
568
569@enumerate
570
571@item Add a call to @file{vcvars32.bat} (which sets up the environment
572variables for the Visual C++ tools) as the first line of @file{msys.bat}.
573The standard location for @file{vcvars32.bat} is
574@file{C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat},
575and the standard location for @file{msys.bat} is @file{C:\msys\1.0\msys.bat}.
576If this corresponds to your setup, add the following line as the first line
577of @file{msys.bat}:
578
579@example
580call "C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat"
581@end example
582
583Alternatively, you may start the @file{Visual Studio 2005 Command Prompt},
584and run @file{c:\msys\1.0\msys.bat} from there.
585
586@item Within the MSYS shell, run @code{lib.exe}. If you get a help message
587from @file{Microsoft (R) Library Manager}, this means your environment
588variables are set up correctly, the @file{Microsoft (R) Library Manager}
589is on the path and will be used by FFmpeg to create
590MSVC++-compatible import libraries.
591
592@item Build FFmpeg with
593
594@example
595./configure --enable-shared --enable-memalign-hack
596make
597make install
598@end example
599
600Your install path (@file{/usr/local/} by default) should now have the
601necessary DLL and LIB files under the @file{bin} directory.
d0e1cd3d
DB
602
603@end enumerate
604
c1989552
RP
605To use those files with MSVC++, do the same as you would do with
606the static libraries, as described above. But in Step 4,
607you should only need to add the directory where the LIB files are installed
608(i.e. @file{c:\msys\usr\local\bin}). This is not a typo, the LIB files are
609installed in the @file{bin} directory. And instead of adding @file{libxx.a}
610files, you should add @file{avcodec.lib}, @file{avformat.lib}, and
611@file{avutil.lib}. There should be no need for @file{libmingwex.a},
612@file{libgcc.a}, and @file{wsock32.lib}, nor any other external library
613statically linked into the DLLs. The @file{bin} directory contains a bunch
614of DLL files, but the ones that are actually used to run your application
615are the ones with a major version number in their filenames
616(i.e. @file{avcodec-51.dll}).
617
d0e1cd3d
DB
618@subsection Cross compilation for Windows with Linux
619
620You must use the MinGW cross compilation tools available at
621@url{http://www.mingw.org/}.
622
623Then configure FFmpeg with the following options:
624@example
625./configure --target-os=mingw32 --cross-prefix=i386-mingw32msvc-
626@end example
627(you can change the cross-prefix according to the prefix chosen for the
628MinGW tools).
629
630Then you can easily test FFmpeg with Wine
631(@url{http://www.winehq.com/}).
632
633@subsection Compilation under Cygwin
634
29c3d42b
VP
635The main issue with Cygwin is that newlib, its C library, does not
636contain llrint(). However, it is possible to leverage the
637implementation in MinGW.
d0e1cd3d
DB
638
639Just install your Cygwin with all the "Base" packages, plus the
640following "Devel" ones:
641@example
29c3d42b 642binutils, gcc-core, make, subversion, mingw-runtime
d0e1cd3d
DB
643@end example
644
645Do not install binutils-20060709-1 (they are buggy on shared builds);
646use binutils-20050610-1 instead.
647
29c3d42b
VP
648Then create a small library that just contains llrint():
649
650@example
651ar x /usr/lib/mingw/libmingwex.a llrint.o
652ar cq /usr/local/lib/libllrint.a llrint.o
653@end example
654
d0e1cd3d
DB
655Then run
656
657@example
29c3d42b 658./configure --enable-static --disable-shared --extra-ldflags='-L /usr/local/lib' --extra-libs='-l llrint'
d0e1cd3d
DB
659@end example
660
661to make a static build or
662
663@example
29c3d42b 664./configure --enable-shared --disable-static --extra-ldflags='-L /usr/local/lib' --extra-libs='-l llrint'
d0e1cd3d
DB
665@end example
666
667to build shared libraries.
668
669If you want to build FFmpeg with additional libraries, download Cygwin
670"Devel" packages for Ogg and Vorbis from any Cygwin packages repository
671and/or SDL, xvid, faac, faad2 packages from Cygwin Ports,
672(@url{http://cygwinports.dotsrc.org/}).
673
674@subsection Crosscompilation for Windows under Cygwin
675
676With Cygwin you can create Windows binaries that do not need the cygwin1.dll.
677
678Just install your Cygwin as explained before, plus these additional
679"Devel" packages:
680@example
681gcc-mingw-core, mingw-runtime, mingw-zlib
682@end example
683
684and add some special flags to your configure invocation.
685
686For a static build run
687@example
688./configure --target-os=mingw32 --enable-memalign-hack --enable-static --disable-shared --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
689@end example
690
691and for a build with shared libraries
692@example
693./configure --target-os=mingw32 --enable-memalign-hack --enable-shared --disable-static --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
694@end example
695
696@section BeOS
697
5f757b85 698BeOS support is broken in mysterious ways.
d0e1cd3d 699
25b92a79
DY
700@section OS/2
701
702For information about compiling FFmpeg on OS/2 see
703@url{http://www.edm2.com/index.php/FFmpeg}.
704
d0e1cd3d
DB
705@chapter Developers Guide
706
707@section API
708@itemize @bullet
709@item libavcodec is the library containing the codecs (both encoding and
710decoding). Look at @file{libavcodec/apiexample.c} to see how to use it.
711
712@item libavformat is the library containing the file format handling (mux and
713demux code for several formats). Look at @file{ffplay.c} to use it in a
714player. See @file{output_example.c} to use it to generate audio or video
715streams.
716
717@end itemize
718
719@section Integrating libavcodec or libavformat in your program
720
721You can integrate all the source code of the libraries to link them
722statically to avoid any version problem. All you need is to provide a
723'config.mak' and a 'config.h' in the parent directory. See the defines
724generated by ./configure to understand what is needed.
725
726You can use libavcodec or libavformat in your commercial program, but
727@emph{any patch you make must be published}. The best way to proceed is
728to send your patches to the FFmpeg mailing list.
729
730@node Coding Rules
731@section Coding Rules
732
733FFmpeg is programmed in the ISO C90 language with a few additional
734features from ISO C99, namely:
735@itemize @bullet
736@item
737the @samp{inline} keyword;
738@item
739@samp{//} comments;
740@item
741designated struct initializers (@samp{struct s x = @{ .i = 17 @};})
742@item
743compound literals (@samp{x = (struct s) @{ 17, 23 @};})
744@end itemize
745
746These features are supported by all compilers we care about, so we will not
747accept patches to remove their use unless they absolutely do not impair
748clarity and performance.
749
750All code must compile with GCC 2.95 and GCC 3.3. Currently, FFmpeg also
751compiles with several other compilers, such as the Compaq ccc compiler
752or Sun Studio 9, and we would like to keep it that way unless it would
753be exceedingly involved. To ensure compatibility, please do not use any
754additional C99 features or GCC extensions. Especially watch out for:
755@itemize @bullet
756@item
757mixing statements and declarations;
758@item
759@samp{long long} (use @samp{int64_t} instead);
760@item
761@samp{__attribute__} not protected by @samp{#ifdef __GNUC__} or similar;
762@item
763GCC statement expressions (@samp{(x = (@{ int y = 4; y; @})}).
764@end itemize
765
766Indent size is 4.
767The presentation is the one specified by 'indent -i4 -kr -nut'.
768The TAB character is forbidden outside of Makefiles as is any
769form of trailing whitespace. Commits containing either will be
770rejected by the Subversion repository.
771
772The main priority in FFmpeg is simplicity and small code size in order to
773minimize the bug count.
774
775Comments: Use the JavaDoc/Doxygen
776format (see examples below) so that code documentation
777can be generated automatically. All nontrivial functions should have a comment
778above them explaining what the function does, even if it is just one sentence.
779All structures and their member variables should be documented, too.
780@example
781/**
782 * @@file mpeg.c
783 * MPEG codec.
784 * @@author ...
785 */
786
787/**
788 * Summary sentence.
789 * more text ...
790 * ...
791 */
792typedef struct Foobar@{
793 int var1; /**< var1 description */
794 int var2; ///< var2 description
795 /** var3 description */
796 int var3;
797@} Foobar;
798
799/**
800 * Summary sentence.
801 * more text ...
802 * ...
803 * @@param my_parameter description of my_parameter
804 * @@return return value description
805 */
806int myfunc(int my_parameter)
807...
808@end example
809
810fprintf and printf are forbidden in libavformat and libavcodec,
811please use av_log() instead.
812
813Casts should be used only when necessary. Unneeded parentheses
814should also be avoided if they don't make the code easier to understand.
815
816@section Development Policy
817
818@enumerate
819@item
820 Contributions should be licensed under the LGPL 2.1, including an
821 "or any later version" clause, or the MIT license. GPL 2 including
822 an "or any later version" clause is also acceptable, but LGPL is
823 preferred.
824@item
825 You must not commit code which breaks FFmpeg! (Meaning unfinished but
826 enabled code which breaks compilation or compiles but does not work or
827 breaks the regression tests)
828 You can commit unfinished stuff (for testing etc), but it must be disabled
829 (#ifdef etc) by default so it does not interfere with other developers'
830 work.
831@item
832 You do not have to over-test things. If it works for you, and you think it
833 should work for others, then commit. If your code has problems
834 (portability, triggers compiler bugs, unusual environment etc) they will be
835 reported and eventually fixed.
836@item
837 Do not commit unrelated changes together, split them into self-contained
838 pieces. Also do not forget that if part B depends on part A, but A does not
839 depend on B, then A can and should be committed first and separate from B.
840 Keeping changes well split into self-contained parts makes reviewing and
841 understanding them on the commit log mailing list easier. This also helps
842 in case of debugging later on.
843 Also if you have doubts about splitting or not splitting, do not hesitate to
844 ask/discuss it on the developer mailing list.
845@item
846 Do not change behavior of the program (renaming options etc) without
847 first discussing it on the ffmpeg-devel mailing list. Do not remove
848 functionality from the code. Just improve!
849
850 Note: Redundant code can be removed.
851@item
852 Do not commit changes to the build system (Makefiles, configure script)
853 which change behavior, defaults etc, without asking first. The same
854 applies to compiler warning fixes, trivial looking fixes and to code
855 maintained by other developers. We usually have a reason for doing things
856 the way we do. Send your changes as patches to the ffmpeg-devel mailing
857 list, and if the code maintainers say OK, you may commit. This does not
858 apply to files you wrote and/or maintain.
859@item
860 We refuse source indentation and other cosmetic changes if they are mixed
861 with functional changes, such commits will be rejected and removed. Every
862 developer has his own indentation style, you should not change it. Of course
863 if you (re)write something, you can use your own style, even though we would
864 prefer if the indentation throughout FFmpeg was consistent (Many projects
865 force a given indentation style - we do not.). If you really need to make
866 indentation changes (try to avoid this), separate them strictly from real
867 changes.
868
869 NOTE: If you had to put if()@{ .. @} over a large (> 5 lines) chunk of code,
870 then either do NOT change the indentation of the inner part within (do not
871 move it to the right)! or do so in a separate commit
872@item
873 Always fill out the commit log message. Describe in a few lines what you
874 changed and why. You can refer to mailing list postings if you fix a
875 particular bug. Comments such as "fixed!" or "Changed it." are unacceptable.
876@item
877 If you apply a patch by someone else, include the name and email address in
878 the log message. Since the ffmpeg-cvslog mailing list is publicly
879 archived you should add some SPAM protection to the email address. Send an
880 answer to ffmpeg-devel (or wherever you got the patch from) saying that
881 you applied the patch.
882@item
883 When applying patches that have been discussed (at length) on the mailing
884 list, reference the thread in the log message.
885@item
886 Do NOT commit to code actively maintained by others without permission.
887 Send a patch to ffmpeg-devel instead. If no one answers within a reasonable
888 timeframe (12h for build failures and security fixes, 3 days small changes,
889 1 week for big patches) then commit your patch if you think it is OK.
890 Also note, the maintainer can simply ask for more time to review!
891@item
892 Subscribe to the ffmpeg-cvslog mailing list. The diffs of all commits
893 are sent there and reviewed by all the other developers. Bugs and possible
894 improvements or general questions regarding commits are discussed there. We
895 expect you to react if problems with your code are uncovered.
896@item
897 Update the documentation if you change behavior or add features. If you are
898 unsure how best to do this, send a patch to ffmpeg-devel, the documentation
899 maintainer(s) will review and commit your stuff.
900@item
901 Try to keep important discussions and requests (also) on the public
902 developer mailing list, so that all developers can benefit from them.
903@item
904 Never write to unallocated memory, never write over the end of arrays,
905 always check values read from some untrusted source before using them
906 as array index or other risky things.
907@item
908 Remember to check if you need to bump versions for the specific libav
909 parts (libavutil, libavcodec, libavformat) you are changing. You need
b98052d5 910 to change the version integer.
d0e1cd3d
DB
911 Incrementing the first component means no backward compatibility to
912 previous versions (e.g. removal of a function from the public API).
913 Incrementing the second component means backward compatible change
b98052d5
PR
914 (e.g. addition of a function to the public API or extension of an
915 existing data structure).
d0e1cd3d
DB
916 Incrementing the third component means a noteworthy binary compatible
917 change (e.g. encoder bug fix that matters for the decoder).
918@item
53407b64 919 Compiler warnings indicate potential bugs or code with bad style. If a type of
9908c1a8
DB
920 warning always points to correct and clean code, that warning should
921 be disabled, not the code changed.
922 Thus the remaining warnings can either be bugs or correct code.
beaa4a91 923 If it is a bug, the bug has to be fixed. If it is not, the code should
9908c1a8
DB
924 be changed to not generate a warning unless that causes a slowdown
925 or obfuscates the code.
d0e1cd3d
DB
926@item
927 If you add a new file, give it a proper license header. Do not copy and
928 paste it from a random place, use an existing file as template.
929@end enumerate
930
931We think our rules are not too hard. If you have comments, contact us.
932
933Note, these rules are mostly borrowed from the MPlayer project.
934
935@section Submitting patches
936
937First, (@pxref{Coding Rules}) above if you did not yet.
938
939When you submit your patch, try to send a unified diff (diff '-up'
940option). We cannot read other diffs :-)
941
942Also please do not submit a patch which contains several unrelated changes.
943Split it into separate, self-contained pieces. This does not mean splitting
944file by file. Instead, make the patch as small as possible while still
945keeping it as a logical unit that contains an individual change, even
946if it spans multiple files. This makes reviewing your patches much easier
947for us and greatly increases your chances of getting your patch applied.
948
949Run the regression tests before submitting a patch so that you can
950verify that there are no big problems.
951
952Patches should be posted as base64 encoded attachments (or any other
953encoding which ensures that the patch will not be trashed during
954transmission) to the ffmpeg-devel mailing list, see
955@url{http://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel}
956
957It also helps quite a bit if you tell us what the patch does (for example
958'replaces lrint by lrintf'), and why (for example '*BSD isn't C99 compliant
959and has no lrint()')
960
961Also please if you send several patches, send each patch as a separate mail,
962do not attach several unrelated patches to the same mail.
963
28ce1839
RP
964@section New codecs or formats checklist
965
966@enumerate
967@item
968 Did you use av_cold for codec initialization and close functions?
969@item
970 Did you add a long_name under NULL_IF_CONFIG_SMALL to the AVCodec or
971 AVInputFormat/AVOutputFormat struct?
972@item
973 Did you bump the minor version number in @file{avcodec.h} or
974 @file{avformat.h}?
975@item
976 Did you register it in @file{allcodecs.c} or @file{allformats.c}?
977@item
978 Did you add the CodecID to @file{avcodec.h}?
979@item
980 If it has a fourcc, did you add it to @file{libavformat/riff.c},
981 even if it is only a decoder?
982@item
983 Did you add a rule to compile the appropriate files in the Makefile?
984 Remember to do this even if you're just adding a format to a file that is
985 already being compiled by some other rule, like a raw demuxer.
986@item
987 Did you add an entry to the table of supported formats or codecs in the
988 documentation?
989@item
990 Did you add an entry in the Changelog?
991@item
992 If it depends on a parser or a library, did you add that dependency in
993 configure?
994@item
995 Did you "svn add" the appropriate files before commiting?
996@end enumerate
997
d0e1cd3d
DB
998@section patch submission checklist
999
1000@enumerate
1001@item
1002 Do the regression tests pass with the patch applied?
1003@item
1004 Is the patch a unified diff?
1005@item
1006 Is the patch against latest FFmpeg SVN?
1007@item
1008 Are you subscribed to ffmpeg-dev?
1009 (the list is subscribers only due to spam)
1010@item
1011 Have you checked that the changes are minimal, so that the same cannot be
1012 achieved with a smaller patch and/or simpler final code?
1013@item
1014 If the change is to speed critical code, did you benchmark it?
1015@item
1016 If you did any benchmarks, did you provide them in the mail?
1017@item
1018 Have you checked that the patch does not introduce buffer overflows or
1019 other security issues?
1020@item
b885e0db
MN
1021 If you add a new demuxer or decoder, have you checked that it does not
1022 crash with damaged input (see tools/trasher)?
1023@item
d0e1cd3d
DB
1024 Is the patch created from the root of the source tree, so it can be
1025 applied with @code{patch -p0}?
1026@item
1027 Does the patch not mix functional and cosmetic changes?
1028@item
1029 Did you add tabs or trailing whitespace to the code? Both are forbidden.
1030@item
1031 Is the patch attached to the email you send?
1032@item
1033 Is the mime type of the patch correct? It should be text/x-diff or
1034 text/x-patch or at least text/plain and not application/octet-stream.
1035@item
1036 If the patch fixes a bug, did you provide a verbose analysis of the bug?
1037@item
1038 If the patch fixes a bug, did you provide enough information, including
1039 a sample, so the bug can be reproduced and the fix can be verified?
1040 Note please do not attach samples >100k to mails but rather provide a
1041 URL, you can upload to ftp://upload.mplayerhq.hu
1042@item
1043 Did you provide a verbose summary about what the patch does change?
1044@item
1045 Did you provide a verbose explanation why it changes things like it does?
1046@item
1047 Did you provide a verbose summary of the user visible advantages and
1048 disadvantages if the patch is applied?
1049@item
1050 Did you provide an example so we can verify the new feature added by the
1051 patch easily?
1052@item
1053 If you added a new file, did you insert a license header? It should be
1054 taken from FFmpeg, not randomly copied and pasted from somewhere else.
1055@item
1056 You should maintain alphabetical order in alphabetically ordered lists as
1057 long as doing so does not break API/ABI compatibility.
1058@item
1059 Lines with similar content should be aligned vertically when doing so
1060 improves readability.
1061@item
1062 Did you provide a suggestion for a clear commit log message?
27250d20
MN
1063@item
1064 Did you test your decoder or demuxer against damaged data? If no, see
1065 tools/trasher and the noise bitstream filter. Your decoder or demuxer
fe74278f 1066 should not crash or end in a (near) infinite loop when fed damaged data.
d0e1cd3d
DB
1067@end enumerate
1068
1069@section Patch review process
1070
1071All patches posted to ffmpeg-devel will be reviewed, unless they contain a
1072clear note that the patch is not for SVN.
1073Reviews and comments will be posted as replies to the patch on the
1074mailing list. The patch submitter then has to take care of every comment,
1075that can be by resubmitting a changed patch or by discussion. Resubmitted
1076patches will themselves be reviewed like any other patch. If at some point
1077a patch passes review with no comments then it is approved, that can for
1078simple and small patches happen immediately while large patches will generally
1079have to be changed and reviewed many times before they are approved.
1080After a patch is approved it will be committed to the repository.
1081
1082We will review all submitted patches, but sometimes we are quite busy so
1083especially for large patches this can take several weeks.
1084
1085When resubmitting patches, please do not make any significant changes
1086not related to the comments received during review. Such patches will
1087be rejected. Instead, submit significant changes or new features as
1088separate patches.
1089
1090@section Regression tests
1091
1092Before submitting a patch (or committing to the repository), you should at least
1093test that you did not break anything.
1094
1095The regression tests build a synthetic video stream and a synthetic
1096audio stream. These are then encoded and decoded with all codecs or
1097formats. The CRC (or MD5) of each generated file is recorded in a
1098result file. A 'diff' is launched to compare the reference results and
1099the result file.
1100
1101The regression tests then go on to test the FFserver code with a
1102limited set of streams. It is important that this step runs correctly
1103as well.
1104
1105Run 'make test' to test all the codecs and formats.
1106
1107Run 'make fulltest' to test all the codecs, formats and FFserver.
1108
1109[Of course, some patches may change the results of the regression tests. In
1110this case, the reference results of the regression tests shall be modified
1111accordingly].
1112
1113@bye