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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
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45 @tab 4X Technologies format, used in some games.
46@item ADTS AAC audio @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.
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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.
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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.
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65@item CRYO APC @tab @tab X
66 @tab Audio format used in some games by CRYO Interactive Entertainment.
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67@item DV @tab X @tab X
68@item DXA @tab @tab X
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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
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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.
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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.
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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.
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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.
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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.
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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
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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.
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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.
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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 '
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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.
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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
82ced5a9 221@item Dirac @tab E @tab E
360f980b 222 @tab supported through 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
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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
42b30357 233@item Electronic Arts TGQ @tab @tab X
d66d8b83 234@item FFmpeg Video 1 @tab X @tab X
d698c5d3 235 @tab experimental lossless codec (fourcc: FFV1)
d66d8b83 236@item Flash Screen Video @tab X @tab X
d698c5d3 237 @tab fourcc: FSV1
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238@item FLIC video @tab @tab X
239@item FLV @tab X @tab X
d698c5d3 240 @tab Sorenson H.263 used in Flash
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241@item Fraps FPS1 @tab @tab X
242@item H.261 @tab X @tab X
243@item H.263(+) @tab X @tab X
d698c5d3 244 @tab also known as RealVideo 1.0
82ced5a9 245@item H.264 @tab E @tab X
360f980b 246 @tab encoding supported through external library libx264
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247@item HuffYUV @tab X @tab X
248@item IBM Ultimotion @tab @tab X
d698c5d3 249 @tab fourcc: ULTI
bac4c85c 250@item id Cinematic video @tab @tab X
d698c5d3 251 @tab Used in Quake II.
d66d8b83 252@item id RoQ @tab X @tab X
d698c5d3 253 @tab Used in Quake III, Jedi Knight 2, other computer games.
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254@item Intel Indeo 3 @tab @tab X
255@item Interplay Video @tab @tab X
d698c5d3 256 @tab Used in Interplay .MVE files.
d66d8b83 257@item JPEG-LS @tab X @tab X
d698c5d3 258 @tab fourcc: MJLS, lossless and near-lossless is supported.
d66d8b83 259@item KMVC @tab @tab X
d698c5d3 260 @tab Codec used in Worms games.
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261@item LOCO @tab @tab X
262@item lossless MJPEG @tab X @tab X
263@item Microsoft RLE @tab @tab X
264@item Microsoft Video-1 @tab @tab X
265@item Mimic @tab @tab X
d698c5d3 266 @tab Used in MSN Messenger Webcam streams.
d66d8b83 267@item Miro VideoXL @tab @tab X
d698c5d3 268 @tab fourcc: VIXL
d66d8b83 269@item MJPEG @tab X @tab X
822cc8f7 270@item Motion Pixels Video @tab @tab X
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271@item MPEG-1 @tab X @tab X
272@item MPEG-2 @tab X @tab X
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273@item MPEG-4 @tab X @tab X
274@item MSMPEG4 V1 @tab X @tab X
275@item MSMPEG4 V2 @tab X @tab X
276@item MSMPEG4 V3 @tab X @tab X
d66d8b83 277@item MSZH @tab @tab X
d698c5d3 278 @tab Part of LCL
d66d8b83 279@item On2 VP3 @tab @tab X
d698c5d3 280 @tab still experimental
d66d8b83 281@item On2 VP5 @tab @tab X
d698c5d3 282 @tab fourcc: VP50
d66d8b83 283@item On2 VP6 @tab @tab X
d698c5d3 284 @tab fourcc: VP60,VP61,VP62
d66d8b83 285@item planar RGB @tab @tab X
d698c5d3 286 @tab fourcc: 8BPS
d66d8b83 287@item QPEG @tab @tab X
d698c5d3 288 @tab fourccs: QPEG, Q1.0, Q1.1
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289@item RealVideo 1.0 @tab X @tab X
290@item RealVideo 2.0 @tab X @tab X
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291@item RealVideo 3.0 @tab @tab X
292 @tab still far from ideal
11c0f9ec 293@item RealVideo 4.0 @tab @tab X
d66d8b83 294@item Renderware TXD @tab @tab X
d698c5d3 295 @tab Texture dictionaries used by the Renderware Engine.
d66d8b83 296@item RTjpeg @tab @tab X
d698c5d3 297 @tab Video encoding used in NuppelVideo files.
bac4c85c 298@item Smacker video @tab @tab X
d698c5d3 299 @tab Video encoding used in Smacker.
d66d8b83 300@item Snow @tab X @tab X
d698c5d3 301 @tab experimental wavelet codec (fourcc: SNOW)
831ec935 302@item Sony PlayStation MDEC @tab @tab X
d66d8b83 303@item Sorenson Video 1 @tab X @tab X
d698c5d3 304 @tab fourcc: SVQ1
d66d8b83 305@item Sorenson Video 3 @tab @tab X
d698c5d3 306 @tab fourcc: SVQ3
d66d8b83 307@item Sunplus MJPEG @tab @tab X
d698c5d3 308 @tab fourcc: SP5X
d66d8b83 309@item TechSmith Camtasia @tab @tab X
d698c5d3 310 @tab fourcc: TSCC
82ced5a9 311@item Theora @tab E @tab X
360f980b 312 @tab encoding supported through external library libtheora
d66d8b83 313@item THP @tab @tab X
d698c5d3 314 @tab Used on the Nintendo GameCube.
bac4c85c 315@item Tiertex Seq video @tab @tab X
d698c5d3 316 @tab Codec used in DOS CD-ROM FlashBack game.
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317@item VC-1 @tab @tab X
318@item VMD Video @tab @tab X
d698c5d3 319 @tab Used in Sierra VMD files.
d66d8b83 320@item VMware Video @tab @tab X
d698c5d3 321 @tab Codec used in videos captured by VMware.
d0e1cd3d 322@item Westwood VQA @tab @tab X
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323@item Winnov WNV1 @tab @tab X
324@item WMV7 @tab X @tab X
325@item WMV8 @tab X @tab X
326@item WMV9 @tab @tab X
d698c5d3 327 @tab not completely working
d66d8b83 328@item Xan/WC3 @tab @tab X
d698c5d3 329 @tab Used in Wing Commander III .MVE files.
d66d8b83 330@item ZLIB @tab X @tab X
d698c5d3 331 @tab part of LCL, encoder experimental
d66d8b83 332@item ZMBV @tab X @tab X
d698c5d3 333 @tab Encoder works only in PAL8.
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334@end multitable
335
336@code{X} means that encoding (resp. decoding) is supported.
337
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338@code{E} means that support is provided through an external library.
339
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340@section Audio Codecs
341
485ec4f1 342@multitable @columnfractions .4 .1 .1 .4
b3de4544 343@item Name @tab Encoding @tab Decoding @tab Comments
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344@item 4X IMA ADPCM @tab @tab X
345@item 8SVX audio @tab @tab X
82ced5a9 346@item AAC @tab E @tab X
360f980b 347 @tab encoding supported through external library libfaac
16d81b27 348@item AC-3 @tab IX @tab IX
82ced5a9 349@item AMR-NB @tab E @tab E
360f980b 350 @tab supported through external library libamrnb
82ced5a9 351@item AMR-WB @tab E @tab E
360f980b 352 @tab supported through external library libamrwb
16d81b27 353@item AMV IMA ADPCM @tab @tab X
d698c5d3 354 @tab Used in AMV files
833e90dd 355@item Apple lossless audio @tab X @tab X
d698c5d3 356 @tab QuickTime fourcc 'alac'
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357@item Apple MACE 3 @tab @tab X
358@item Apple MACE 6 @tab @tab X
359@item ATRAC 3 @tab @tab X
360@item CD-ROM XA ADPCM @tab @tab X
bac4c85c 361@item Cin audio @tab @tab X
d698c5d3 362 @tab Codec used in Delphine Software International games.
16d81b27 363@item Creative ADPCM @tab @tab X
d698c5d3 364 @tab 16 -> 4, 8 -> 4, 8 -> 3, 8 -> 2
16d81b27 365@item CRI ADX ADPCM @tab X @tab X
d698c5d3 366 @tab Used in Sega Dreamcast games.
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367@item DSP Group TrueSpeech @tab @tab X
368@item DTS Coherent Audio @tab @tab X
369@item Duck DK3 IMA ADPCM @tab @tab X
d698c5d3 370 @tab Used in some Sega Saturn console games.
16d81b27 371@item Duck DK4 IMA ADPCM @tab @tab X
d698c5d3 372 @tab Used in some Sega Saturn console games.
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373@item DV audio @tab @tab X
374@item Electronic Arts ADPCM @tab @tab X
d698c5d3 375 @tab Used in various EA titles.
44723c84 376@item Enhanced AC-3 @tab @tab X
9a584db4 377@item FLAC lossless audio @tab IX @tab X
16d81b27 378@item G.726 ADPCM @tab X @tab X
82ced5a9 379@item GSM @tab E @tab E
3f33271a 380 @tab supported through external library libgsm
82ced5a9 381@item GSM_MS @tab E @tab E
3f33271a 382 @tab supported through external library libgsm
16d81b27 383@item id RoQ DPCM @tab X @tab X
d698c5d3 384 @tab Used in Quake III, Jedi Knight 2, other computer games.
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385@item Intel Music Coder @tab @tab X
386@item Interplay MVE DPCM @tab @tab X
d698c5d3 387 @tab Used in various Interplay computer games.
16d81b27 388@item MAXIS EA ADPCM @tab @tab X
d698c5d3 389 @tab Used in Sim City 3000.
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390@item Microsoft ADPCM @tab X @tab X
391@item MLP/TrueHD @tab @tab X
d698c5d3 392 @tab Used in DVD-Audio and Blu-Ray discs.
16d81b27 393@item Monkey's Audio @tab @tab X
d698c5d3 394 @tab Only versions 3.97-3.99 are supported.
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395@item MPEG audio layer 3 @tab E @tab IX
396 @tab encoding supported through external library LAME
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397@item MPEG audio layer 2 @tab IX @tab IX
398@item MS IMA ADPCM @tab X @tab X
399@item Musepack @tab @tab X
d698c5d3 400 @tab SV7 and SV8 are supported.
755ba886 401@item Nellymoser ASAO @tab X @tab X
73b458e3 402@item QCELP / PureVoice @tab @tab X
16d81b27 403@item Qdesign QDM2 @tab @tab X
d698c5d3 404 @tab There are still some distortions.
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405@item QT IMA ADPCM @tab X @tab X
406@item RA144 @tab @tab X
d698c5d3 407 @tab Real 14400 bit/s codec
16d81b27 408@item RA288 @tab @tab X
d698c5d3 409 @tab Real 28800 bit/s codec
575a5bf2 410@item RADnet @tab IX @tab IX
a692130f 411 @tab Real low bitrate AC-3 codec
16d81b27 412@item Real COOK @tab @tab X
d698c5d3 413 @tab All versions except 5.1 are supported.
bac4c85c 414@item Shorten @tab @tab X
16d81b27 415@item Sierra Online DPCM @tab @tab X
d698c5d3 416 @tab Used in Sierra Online game audio files.
bac4c85c 417@item Smacker audio @tab @tab X
16d81b27 418@item SMJPEG IMA ADPCM @tab @tab X
d698c5d3 419 @tab Used in certain Loki game ports.
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420@item Sonic @tab X @tab X
421 @tab experimental codec
422@item Sonic lossless @tab X @tab X
423 @tab experimental codec
82ced5a9 424@item Speex @tab @tab E
360f980b 425 @tab supported through external library libspeex
16d81b27 426@item THP ADPCM @tab @tab X
d698c5d3 427 @tab Used on the Nintendo GameCube.
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428@item True Audio (TTA) @tab @tab X
429@item Vorbis @tab X @tab X
bac4c85c 430@item WavPack @tab @tab X
16d81b27 431@item Westwood Studios IMA ADPCM @tab @tab X
d698c5d3 432 @tab Used in Westwood Studios games like Command and Conquer.
bac4c85c 433@item WMA v1/v2 @tab X @tab X
16d81b27 434@item Xan DPCM @tab @tab X
d698c5d3 435 @tab Used in Origin's Wing Commander IV AVI files.
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436@end multitable
437
438@code{X} means that encoding (resp. decoding) is supported.
439
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440@code{E} means that support is provided through an external library.
441
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442@code{I} means that an integer-only version is available, too (ensures high
443performance on systems without hardware floating point support).
444
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445@section Subtitle Formats
446
485ec4f1 447@multitable @columnfractions .4 .1 .1 .1 .1 .1
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448@item Name @tab Muxing @tab Demuxing @tab Encoding @tab Decoding @tab Rendering
449@item ASS/SSA @tab X @tab X
450@item DVB @tab X @tab X @tab X @tab X @tab X
451@item DVD @tab X @tab X @tab X @tab X @tab X
452@end multitable
453
454@code{X} means that the feature is supported.
455
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456@chapter Platform Specific information
457
458@section BSD
459
460BSD make will not build FFmpeg, you need to install and use GNU Make
461(@file{gmake}).
462
463@section Windows
464
46a845d0 465To get help and instructions for building FFmpeg under Windows, check out
d0e1cd3d 466the FFmpeg Windows Help Forum at
ab5ce4ae 467@url{http://ffmpeg.arrozcru.org/}.
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468
469@subsection Native Windows compilation
470
c1989552 471FFmpeg can be built to run natively on Windows using the MinGW tools. Install
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472the latest versions of MSYS and MinGW from @url{http://www.mingw.org/}.
473You can find detailed installation
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474instructions in the download section and the FAQ.
475
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476FFmpeg does not build out-of-the-box with the packages the automated MinGW
477installer provides. It also requires coreutils to be installed and many other
478packages updated to the latest version. The minimum version for some packages
479are listed below:
480
481@itemize
482@item bash 3.1
483@item msys-make 3.81-2 (note: not mingw32-make)
2014b51c 484@item w32api 3.13
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485@item mingw-runtime 3.15
486@end itemize
487
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488You will also need to pass @code{-fno-common} to the compiler to work around
489a GCC bug (see @url{http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37216}).
490
c1989552 491Within the MSYS shell, configure and make with:
d0e1cd3d 492
c1989552 493@example
0f898714 494./configure --enable-memalign-hack --extra-cflags=-fno-common
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495make
496make install
497@end example
d0e1cd3d 498
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499This will install @file{ffmpeg.exe} along with many other development files
500to @file{/usr/local}. You may specify another install path using the
501@code{--prefix} option in @file{configure}.
d0e1cd3d 502
c1989552 503Notes:
d0e1cd3d 504
c1989552 505@itemize
d0e1cd3d 506
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507@item In order to compile vhooks, you must have a POSIX-compliant libdl in
508your MinGW system. Get dlfcn-win32 from
509@url{http://code.google.com/p/dlfcn-win32}.
d0e1cd3d 510
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511@item In order to compile FFplay, you must have the MinGW development library
512of SDL. Get it from @url{http://www.libsdl.org}.
513Edit the @file{bin/sdl-config} script so that it points to the correct prefix
514where SDL was installed. Verify that @file{sdl-config} can be launched from
515the MSYS command line.
d0e1cd3d 516
d0e1cd3d 517@item By using @code{./configure --enable-shared} when configuring FFmpeg,
c1989552 518you can build libavutil, libavcodec and libavformat as DLLs.
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519
520@end itemize
521
c1989552 522@subsection Microsoft Visual C++ compatibility
d0e1cd3d 523
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524As stated in the FAQ, FFmpeg will not compile under MSVC++. However, if you
525want to use the libav* libraries in your own applications, you can still
526compile those applications using MSVC++. But the libav* libraries you link
527to @emph{must} be built with MinGW. However, you will not be able to debug
528inside the libav* libraries, since MSVC++ does not recognize the debug
529symbols generated by GCC.
530We strongly recommend you to move over from MSVC++ to MinGW tools.
d0e1cd3d 531
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532This description of how to use the FFmpeg libraries with MSVC++ is based on
533Microsoft Visual C++ 2005 Express Edition. If you have a different version,
534you might have to modify the procedures slightly.
d0e1cd3d 535
c1989552 536@subsubsection Using static libraries
d0e1cd3d 537
c1989552 538Assuming you have just built and installed FFmpeg in @file{/usr/local}.
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539
540@enumerate
541
542@item Create a new console application ("File / New / Project") and then
543select "Win32 Console Application". On the appropriate page of the
544Application Wizard, uncheck the "Precompiled headers" option.
545
546@item Write the source code for your application, or, for testing, just
547copy the code from an existing sample application into the source file
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548that MSVC++ has already created for you. For example, you can copy
549@file{output_example.c} from the FFmpeg distribution.
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550
551@item Open the "Project / Properties" dialog box. In the "Configuration"
552combo box, select "All Configurations" so that the changes you make will
553affect both debug and release builds. In the tree view on the left hand
554side, select "C/C++ / General", then edit the "Additional Include
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555Directories" setting to contain the path where the FFmpeg includes were
556installed (i.e. @file{c:\msys\1.0\local\include}).
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557Do not add MinGW's include directory here, or the include files will
558conflict with MSVC's.
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559
560@item Still in the "Project / Properties" dialog box, select
561"Linker / General" from the tree view and edit the
562"Additional Library Directories" setting to contain the @file{lib}
563directory where FFmpeg was installed (i.e. @file{c:\msys\1.0\local\lib}),
564the directory where MinGW libs are installed (i.e. @file{c:\mingw\lib}),
565and the directory where MinGW's GCC libs are installed
566(i.e. @file{C:\mingw\lib\gcc\mingw32\4.2.1-sjlj}). Then select
567"Linker / Input" from the tree view, and add the files @file{libavformat.a},
568@file{libavcodec.a}, @file{libavutil.a}, @file{libmingwex.a},
569@file{libgcc.a}, and any other libraries you used (i.e. @file{libz.a})
570to the end of "Additional Dependencies".
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571
572@item Now, select "C/C++ / Code Generation" from the tree view. Select
573"Debug" in the "Configuration" combo box. Make sure that "Runtime
574Library" is set to "Multi-threaded Debug DLL". Then, select "Release" in
575the "Configuration" combo box and make sure that "Runtime Library" is
576set to "Multi-threaded DLL".
577
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578@item Click "OK" to close the "Project / Properties" dialog box.
579
580@item MSVC++ lacks some C99 header files that are fundamental for FFmpeg.
581Get msinttypes from @url{http://code.google.com/p/msinttypes/downloads/list}
582and install it in MSVC++'s include directory
583(i.e. @file{C:\Program Files\Microsoft Visual Studio 8\VC\include}).
584
585@item MSVC++ also does not understand the @code{inline} keyword used by
586FFmpeg, so you must add this line before @code{#include}ing libav*:
587@example
588#define inline _inline
589@end example
590
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591@item Build your application, everything should work.
592
593@end enumerate
594
595@subsubsection Using shared libraries
596
597This is how to create DLL and LIB files that are compatible with MSVC++:
598
599@enumerate
600
601@item Add a call to @file{vcvars32.bat} (which sets up the environment
602variables for the Visual C++ tools) as the first line of @file{msys.bat}.
603The standard location for @file{vcvars32.bat} is
604@file{C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat},
605and the standard location for @file{msys.bat} is @file{C:\msys\1.0\msys.bat}.
606If this corresponds to your setup, add the following line as the first line
607of @file{msys.bat}:
608
609@example
610call "C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat"
611@end example
612
613Alternatively, you may start the @file{Visual Studio 2005 Command Prompt},
614and run @file{c:\msys\1.0\msys.bat} from there.
615
616@item Within the MSYS shell, run @code{lib.exe}. If you get a help message
617from @file{Microsoft (R) Library Manager}, this means your environment
618variables are set up correctly, the @file{Microsoft (R) Library Manager}
619is on the path and will be used by FFmpeg to create
620MSVC++-compatible import libraries.
621
622@item Build FFmpeg with
623
624@example
625./configure --enable-shared --enable-memalign-hack
626make
627make install
628@end example
629
630Your install path (@file{/usr/local/} by default) should now have the
631necessary DLL and LIB files under the @file{bin} directory.
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632
633@end enumerate
634
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635To use those files with MSVC++, do the same as you would do with
636the static libraries, as described above. But in Step 4,
637you should only need to add the directory where the LIB files are installed
638(i.e. @file{c:\msys\usr\local\bin}). This is not a typo, the LIB files are
639installed in the @file{bin} directory. And instead of adding @file{libxx.a}
640files, you should add @file{avcodec.lib}, @file{avformat.lib}, and
641@file{avutil.lib}. There should be no need for @file{libmingwex.a},
642@file{libgcc.a}, and @file{wsock32.lib}, nor any other external library
643statically linked into the DLLs. The @file{bin} directory contains a bunch
644of DLL files, but the ones that are actually used to run your application
645are the ones with a major version number in their filenames
646(i.e. @file{avcodec-51.dll}).
647
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648@subsection Cross compilation for Windows with Linux
649
650You must use the MinGW cross compilation tools available at
651@url{http://www.mingw.org/}.
652
653Then configure FFmpeg with the following options:
654@example
655./configure --target-os=mingw32 --cross-prefix=i386-mingw32msvc-
656@end example
657(you can change the cross-prefix according to the prefix chosen for the
658MinGW tools).
659
660Then you can easily test FFmpeg with Wine
661(@url{http://www.winehq.com/}).
662
663@subsection Compilation under Cygwin
664
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665The main issue with the 1.5.x Cygwin versions is that newlib, its C library,
666does not contain llrint(). You need to upgrade to the unstable 1.7.x versions,
667or leverage the implementation in MinGW (as explained below).
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668
669Just install your Cygwin with all the "Base" packages, plus the
670following "Devel" ones:
671@example
f496ab12 672binutils, gcc-core, make, subversion, mingw-runtime, diffutils
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673@end example
674
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675The experimental gcc4 package is still buggy, hence please
676use the official gcc 3.4.4 or a 4.2.x compiled from source by yourself.
677
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678Install the current binutils-20080624-2 as they work fine (the old
679binutils-20060709-1 proved buggy on shared builds).
d0e1cd3d 680
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681Then create a small library that just contains llrint():
682
683@example
684ar x /usr/lib/mingw/libmingwex.a llrint.o
685ar cq /usr/local/lib/libllrint.a llrint.o
686@end example
687
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688Then run
689
690@example
29c3d42b 691./configure --enable-static --disable-shared --extra-ldflags='-L /usr/local/lib' --extra-libs='-l llrint'
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692@end example
693
694to make a static build or
695
696@example
29c3d42b 697./configure --enable-shared --disable-static --extra-ldflags='-L /usr/local/lib' --extra-libs='-l llrint'
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698@end example
699
700to build shared libraries.
701
702If you want to build FFmpeg with additional libraries, download Cygwin
703"Devel" packages for Ogg and Vorbis from any Cygwin packages repository
704and/or SDL, xvid, faac, faad2 packages from Cygwin Ports,
9f6bfe80 705(@url{http://sourceware.org/cygwinports/}).
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706
707@subsection Crosscompilation for Windows under Cygwin
708
709With Cygwin you can create Windows binaries that do not need the cygwin1.dll.
710
711Just install your Cygwin as explained before, plus these additional
712"Devel" packages:
713@example
714gcc-mingw-core, mingw-runtime, mingw-zlib
715@end example
716
717and add some special flags to your configure invocation.
718
719For a static build run
720@example
721./configure --target-os=mingw32 --enable-memalign-hack --enable-static --disable-shared --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
722@end example
723
724and for a build with shared libraries
725@example
726./configure --target-os=mingw32 --enable-memalign-hack --enable-shared --disable-static --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
727@end example
728
729@section BeOS
730
5f757b85 731BeOS support is broken in mysterious ways.
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733@section OS/2
734
735For information about compiling FFmpeg on OS/2 see
736@url{http://www.edm2.com/index.php/FFmpeg}.
737
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738@chapter Developers Guide
739
740@section API
741@itemize @bullet
742@item libavcodec is the library containing the codecs (both encoding and
743decoding). Look at @file{libavcodec/apiexample.c} to see how to use it.
744
745@item libavformat is the library containing the file format handling (mux and
746demux code for several formats). Look at @file{ffplay.c} to use it in a
747player. See @file{output_example.c} to use it to generate audio or video
748streams.
749
750@end itemize
751
752@section Integrating libavcodec or libavformat in your program
753
754You can integrate all the source code of the libraries to link them
755statically to avoid any version problem. All you need is to provide a
756'config.mak' and a 'config.h' in the parent directory. See the defines
757generated by ./configure to understand what is needed.
758
759You can use libavcodec or libavformat in your commercial program, but
760@emph{any patch you make must be published}. The best way to proceed is
761to send your patches to the FFmpeg mailing list.
762
763@node Coding Rules
764@section Coding Rules
765
766FFmpeg is programmed in the ISO C90 language with a few additional
767features from ISO C99, namely:
768@itemize @bullet
769@item
770the @samp{inline} keyword;
771@item
772@samp{//} comments;
773@item
774designated struct initializers (@samp{struct s x = @{ .i = 17 @};})
775@item
776compound literals (@samp{x = (struct s) @{ 17, 23 @};})
777@end itemize
778
779These features are supported by all compilers we care about, so we will not
780accept patches to remove their use unless they absolutely do not impair
781clarity and performance.
782
783All code must compile with GCC 2.95 and GCC 3.3. Currently, FFmpeg also
784compiles with several other compilers, such as the Compaq ccc compiler
785or Sun Studio 9, and we would like to keep it that way unless it would
786be exceedingly involved. To ensure compatibility, please do not use any
787additional C99 features or GCC extensions. Especially watch out for:
788@itemize @bullet
789@item
790mixing statements and declarations;
791@item
792@samp{long long} (use @samp{int64_t} instead);
793@item
794@samp{__attribute__} not protected by @samp{#ifdef __GNUC__} or similar;
795@item
796GCC statement expressions (@samp{(x = (@{ int y = 4; y; @})}).
797@end itemize
798
799Indent size is 4.
800The presentation is the one specified by 'indent -i4 -kr -nut'.
801The TAB character is forbidden outside of Makefiles as is any
802form of trailing whitespace. Commits containing either will be
803rejected by the Subversion repository.
804
805The main priority in FFmpeg is simplicity and small code size in order to
806minimize the bug count.
807
808Comments: Use the JavaDoc/Doxygen
809format (see examples below) so that code documentation
810can be generated automatically. All nontrivial functions should have a comment
811above them explaining what the function does, even if it is just one sentence.
812All structures and their member variables should be documented, too.
813@example
814/**
815 * @@file mpeg.c
816 * MPEG codec.
817 * @@author ...
818 */
819
820/**
821 * Summary sentence.
822 * more text ...
823 * ...
824 */
825typedef struct Foobar@{
826 int var1; /**< var1 description */
827 int var2; ///< var2 description
828 /** var3 description */
829 int var3;
830@} Foobar;
831
832/**
833 * Summary sentence.
834 * more text ...
835 * ...
836 * @@param my_parameter description of my_parameter
837 * @@return return value description
838 */
839int myfunc(int my_parameter)
840...
841@end example
842
843fprintf and printf are forbidden in libavformat and libavcodec,
844please use av_log() instead.
845
846Casts should be used only when necessary. Unneeded parentheses
847should also be avoided if they don't make the code easier to understand.
848
849@section Development Policy
850
851@enumerate
852@item
853 Contributions should be licensed under the LGPL 2.1, including an
854 "or any later version" clause, or the MIT license. GPL 2 including
855 an "or any later version" clause is also acceptable, but LGPL is
856 preferred.
857@item
858 You must not commit code which breaks FFmpeg! (Meaning unfinished but
859 enabled code which breaks compilation or compiles but does not work or
860 breaks the regression tests)
861 You can commit unfinished stuff (for testing etc), but it must be disabled
862 (#ifdef etc) by default so it does not interfere with other developers'
863 work.
864@item
865 You do not have to over-test things. If it works for you, and you think it
866 should work for others, then commit. If your code has problems
867 (portability, triggers compiler bugs, unusual environment etc) they will be
868 reported and eventually fixed.
869@item
870 Do not commit unrelated changes together, split them into self-contained
871 pieces. Also do not forget that if part B depends on part A, but A does not
872 depend on B, then A can and should be committed first and separate from B.
873 Keeping changes well split into self-contained parts makes reviewing and
874 understanding them on the commit log mailing list easier. This also helps
875 in case of debugging later on.
876 Also if you have doubts about splitting or not splitting, do not hesitate to
877 ask/discuss it on the developer mailing list.
878@item
879 Do not change behavior of the program (renaming options etc) without
880 first discussing it on the ffmpeg-devel mailing list. Do not remove
881 functionality from the code. Just improve!
882
883 Note: Redundant code can be removed.
884@item
885 Do not commit changes to the build system (Makefiles, configure script)
886 which change behavior, defaults etc, without asking first. The same
887 applies to compiler warning fixes, trivial looking fixes and to code
888 maintained by other developers. We usually have a reason for doing things
889 the way we do. Send your changes as patches to the ffmpeg-devel mailing
890 list, and if the code maintainers say OK, you may commit. This does not
891 apply to files you wrote and/or maintain.
892@item
893 We refuse source indentation and other cosmetic changes if they are mixed
894 with functional changes, such commits will be rejected and removed. Every
895 developer has his own indentation style, you should not change it. Of course
896 if you (re)write something, you can use your own style, even though we would
897 prefer if the indentation throughout FFmpeg was consistent (Many projects
898 force a given indentation style - we do not.). If you really need to make
899 indentation changes (try to avoid this), separate them strictly from real
900 changes.
901
902 NOTE: If you had to put if()@{ .. @} over a large (> 5 lines) chunk of code,
903 then either do NOT change the indentation of the inner part within (do not
904 move it to the right)! or do so in a separate commit
905@item
906 Always fill out the commit log message. Describe in a few lines what you
907 changed and why. You can refer to mailing list postings if you fix a
908 particular bug. Comments such as "fixed!" or "Changed it." are unacceptable.
909@item
910 If you apply a patch by someone else, include the name and email address in
911 the log message. Since the ffmpeg-cvslog mailing list is publicly
912 archived you should add some SPAM protection to the email address. Send an
913 answer to ffmpeg-devel (or wherever you got the patch from) saying that
914 you applied the patch.
915@item
916 When applying patches that have been discussed (at length) on the mailing
917 list, reference the thread in the log message.
918@item
919 Do NOT commit to code actively maintained by others without permission.
920 Send a patch to ffmpeg-devel instead. If no one answers within a reasonable
921 timeframe (12h for build failures and security fixes, 3 days small changes,
922 1 week for big patches) then commit your patch if you think it is OK.
923 Also note, the maintainer can simply ask for more time to review!
924@item
925 Subscribe to the ffmpeg-cvslog mailing list. The diffs of all commits
926 are sent there and reviewed by all the other developers. Bugs and possible
927 improvements or general questions regarding commits are discussed there. We
928 expect you to react if problems with your code are uncovered.
929@item
930 Update the documentation if you change behavior or add features. If you are
931 unsure how best to do this, send a patch to ffmpeg-devel, the documentation
932 maintainer(s) will review and commit your stuff.
933@item
934 Try to keep important discussions and requests (also) on the public
935 developer mailing list, so that all developers can benefit from them.
936@item
937 Never write to unallocated memory, never write over the end of arrays,
938 always check values read from some untrusted source before using them
939 as array index or other risky things.
940@item
941 Remember to check if you need to bump versions for the specific libav
942 parts (libavutil, libavcodec, libavformat) you are changing. You need
b98052d5 943 to change the version integer.
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944 Incrementing the first component means no backward compatibility to
945 previous versions (e.g. removal of a function from the public API).
946 Incrementing the second component means backward compatible change
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947 (e.g. addition of a function to the public API or extension of an
948 existing data structure).
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949 Incrementing the third component means a noteworthy binary compatible
950 change (e.g. encoder bug fix that matters for the decoder).
951@item
53407b64 952 Compiler warnings indicate potential bugs or code with bad style. If a type of
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953 warning always points to correct and clean code, that warning should
954 be disabled, not the code changed.
955 Thus the remaining warnings can either be bugs or correct code.
beaa4a91 956 If it is a bug, the bug has to be fixed. If it is not, the code should
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957 be changed to not generate a warning unless that causes a slowdown
958 or obfuscates the code.
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959@item
960 If you add a new file, give it a proper license header. Do not copy and
961 paste it from a random place, use an existing file as template.
962@end enumerate
963
964We think our rules are not too hard. If you have comments, contact us.
965
966Note, these rules are mostly borrowed from the MPlayer project.
967
968@section Submitting patches
969
970First, (@pxref{Coding Rules}) above if you did not yet.
971
972When you submit your patch, try to send a unified diff (diff '-up'
973option). We cannot read other diffs :-)
974
975Also please do not submit a patch which contains several unrelated changes.
976Split it into separate, self-contained pieces. This does not mean splitting
977file by file. Instead, make the patch as small as possible while still
978keeping it as a logical unit that contains an individual change, even
979if it spans multiple files. This makes reviewing your patches much easier
980for us and greatly increases your chances of getting your patch applied.
981
982Run the regression tests before submitting a patch so that you can
983verify that there are no big problems.
984
985Patches should be posted as base64 encoded attachments (or any other
986encoding which ensures that the patch will not be trashed during
987transmission) to the ffmpeg-devel mailing list, see
988@url{http://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel}
989
990It also helps quite a bit if you tell us what the patch does (for example
991'replaces lrint by lrintf'), and why (for example '*BSD isn't C99 compliant
992and has no lrint()')
993
994Also please if you send several patches, send each patch as a separate mail,
995do not attach several unrelated patches to the same mail.
996
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997@section New codecs or formats checklist
998
999@enumerate
1000@item
1001 Did you use av_cold for codec initialization and close functions?
1002@item
1003 Did you add a long_name under NULL_IF_CONFIG_SMALL to the AVCodec or
1004 AVInputFormat/AVOutputFormat struct?
1005@item
1006 Did you bump the minor version number in @file{avcodec.h} or
1007 @file{avformat.h}?
1008@item
1009 Did you register it in @file{allcodecs.c} or @file{allformats.c}?
1010@item
1011 Did you add the CodecID to @file{avcodec.h}?
1012@item
1013 If it has a fourcc, did you add it to @file{libavformat/riff.c},
1014 even if it is only a decoder?
1015@item
1016 Did you add a rule to compile the appropriate files in the Makefile?
1017 Remember to do this even if you're just adding a format to a file that is
1018 already being compiled by some other rule, like a raw demuxer.
1019@item
1020 Did you add an entry to the table of supported formats or codecs in the
1021 documentation?
1022@item
1023 Did you add an entry in the Changelog?
1024@item
1025 If it depends on a parser or a library, did you add that dependency in
1026 configure?
1027@item
1028 Did you "svn add" the appropriate files before commiting?
1029@end enumerate
1030
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1031@section patch submission checklist
1032
1033@enumerate
1034@item
1035 Do the regression tests pass with the patch applied?
1036@item
2cdba8bf
DB
1037 Does @code{make checkheaders} pass with the patch applied?
1038@item
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DB
1039 Is the patch a unified diff?
1040@item
1041 Is the patch against latest FFmpeg SVN?
1042@item
1043 Are you subscribed to ffmpeg-dev?
1044 (the list is subscribers only due to spam)
1045@item
1046 Have you checked that the changes are minimal, so that the same cannot be
1047 achieved with a smaller patch and/or simpler final code?
1048@item
1049 If the change is to speed critical code, did you benchmark it?
1050@item
1051 If you did any benchmarks, did you provide them in the mail?
1052@item
1053 Have you checked that the patch does not introduce buffer overflows or
1054 other security issues?
1055@item
63d247ea
DB
1056 Did you test your decoder or demuxer against damaged data? If no, see
1057 tools/trasher and the noise bitstream filter. Your decoder or demuxer
1058 should not crash or end in a (near) infinite loop when fed damaged data.
b885e0db 1059@item
d0e1cd3d
DB
1060 Is the patch created from the root of the source tree, so it can be
1061 applied with @code{patch -p0}?
1062@item
1063 Does the patch not mix functional and cosmetic changes?
1064@item
1065 Did you add tabs or trailing whitespace to the code? Both are forbidden.
1066@item
1067 Is the patch attached to the email you send?
1068@item
1069 Is the mime type of the patch correct? It should be text/x-diff or
1070 text/x-patch or at least text/plain and not application/octet-stream.
1071@item
1072 If the patch fixes a bug, did you provide a verbose analysis of the bug?
1073@item
1074 If the patch fixes a bug, did you provide enough information, including
1075 a sample, so the bug can be reproduced and the fix can be verified?
1076 Note please do not attach samples >100k to mails but rather provide a
1077 URL, you can upload to ftp://upload.mplayerhq.hu
1078@item
1079 Did you provide a verbose summary about what the patch does change?
1080@item
1081 Did you provide a verbose explanation why it changes things like it does?
1082@item
1083 Did you provide a verbose summary of the user visible advantages and
1084 disadvantages if the patch is applied?
1085@item
1086 Did you provide an example so we can verify the new feature added by the
1087 patch easily?
1088@item
1089 If you added a new file, did you insert a license header? It should be
1090 taken from FFmpeg, not randomly copied and pasted from somewhere else.
1091@item
1092 You should maintain alphabetical order in alphabetically ordered lists as
1093 long as doing so does not break API/ABI compatibility.
1094@item
1095 Lines with similar content should be aligned vertically when doing so
1096 improves readability.
1097@item
1098 Did you provide a suggestion for a clear commit log message?
1099@end enumerate
1100
1101@section Patch review process
1102
1103All patches posted to ffmpeg-devel will be reviewed, unless they contain a
1104clear note that the patch is not for SVN.
1105Reviews and comments will be posted as replies to the patch on the
1106mailing list. The patch submitter then has to take care of every comment,
1107that can be by resubmitting a changed patch or by discussion. Resubmitted
1108patches will themselves be reviewed like any other patch. If at some point
1109a patch passes review with no comments then it is approved, that can for
1110simple and small patches happen immediately while large patches will generally
1111have to be changed and reviewed many times before they are approved.
1112After a patch is approved it will be committed to the repository.
1113
1114We will review all submitted patches, but sometimes we are quite busy so
1115especially for large patches this can take several weeks.
1116
1117When resubmitting patches, please do not make any significant changes
1118not related to the comments received during review. Such patches will
1119be rejected. Instead, submit significant changes or new features as
1120separate patches.
1121
1122@section Regression tests
1123
1124Before submitting a patch (or committing to the repository), you should at least
1125test that you did not break anything.
1126
1127The regression tests build a synthetic video stream and a synthetic
1128audio stream. These are then encoded and decoded with all codecs or
1129formats. The CRC (or MD5) of each generated file is recorded in a
1130result file. A 'diff' is launched to compare the reference results and
1131the result file.
1132
1133The regression tests then go on to test the FFserver code with a
1134limited set of streams. It is important that this step runs correctly
1135as well.
1136
1137Run 'make test' to test all the codecs and formats.
1138
1139Run 'make fulltest' to test all the codecs, formats and FFserver.
1140
1141[Of course, some patches may change the results of the regression tests. In
1142this case, the reference results of the regression tests shall be modified
1143accordingly].
1144
1145@bye