Split PGM and PPM in image formats section.
[libav.git] / doc / general.texi
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1\input texinfo @c -*- texinfo -*-
2
3@settitle General Documentation
4@titlepage
5@sp 7
6@center @titlefont{General Documentation}
7@sp 3
8@end titlepage
9
10
11@chapter external libraries
12
13FFmpeg can be hooked up with a number of external libraries to add support
14for more formats. None of them are used by default, their use has to be
15explicitly requested by passing the appropriate flags to @file{./configure}.
16
17@section AMR
18
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19AMR comes in two different flavors, wideband and narrowband. FFmpeg can make
20use of the AMR wideband (floating-point mode) and the AMR narrowband
21(floating-point mode) reference decoders and encoders.
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22
23Go to @url{http://www.penguin.cz/~utx/amr} and follow the instructions for
24installing the libraries. Then pass @code{--enable-libamr-nb} and/or
25@code{--enable-libamr-wb} to configure to enable the libraries.
26
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27Note that libamr is copyrighted without any sort of license grant. This means
28that you can use it if you legally obtained it but you are not allowed to
29redistribute it in any way. @strong{Any FFmpeg binaries with libamr support
30you create are non-free and unredistributable!}
31
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32
33@chapter Supported File Formats and Codecs
34
35You can use the @code{-formats} option to have an exhaustive list.
36
37@section File Formats
38
39FFmpeg supports the following file formats through the @code{libavformat}
40library:
41
42@multitable @columnfractions .4 .1 .1 .4
b3de4544 43@item Name @tab Encoding @tab Decoding @tab Comments
64c2f20a 44@item 4xm @tab @tab X
c6b2dc34 45 @tab 4X Technologies format, used in some games.
39271be4 46@item Audio IFF (AIFF) @tab X @tab X
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47@item American Laser Games MM @tab @tab X
48 @tab Multimedia format used in games like Mad Dog McCree.
39271be4 49@item 3GPP AMR @tab X @tab X
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50@item ASF @tab X @tab X
51@item AVI @tab X @tab X
39271be4 52@item AVISynth @tab @tab X
c6b2dc34 53@item AVS @tab @tab X
d698c5d3 54 @tab Multimedia format used by the Creature Shock game.
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55@item Beam Software SIFF @tab @tab X
56 @tab Audio and video format used in some games by Beam Software.
57@item Bethesda Softworks VID @tab @tab X
d698c5d3 58 @tab Used in some games from Bethesda Softworks.
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59@item Brute Force & Ignorance @tab @tab X
60 @tab Used in the game Flash Traffic: City of Angels.
61@item Interplay C93 @tab @tab X
d698c5d3 62 @tab Used in the game Cyberia from Interplay.
913c3e2c 63@item Delphine Software International CIN @tab @tab X
d698c5d3 64 @tab Multimedia format used by Delphine Software games.
39271be4 65@item CRC testing format @tab X @tab
913c3e2c 66@item Creative Voice @tab X @tab X
d698c5d3 67 @tab Created for the Sound Blaster Pro.
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68@item CRYO APC @tab @tab X
69 @tab Audio format used in some games by CRYO Interactive Entertainment.
39271be4 70@item D-Cinema audio @tab X @tab X
913c3e2c 71@item DV video @tab X @tab X
c6b2dc34 72@item DXA @tab @tab X
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73 @tab This format is used in the non-Windows version of the Feeble Files
74 game and different game cutscenes repacked for use with ScummVM.
39271be4 75@item Electronic Arts cdata @tab @tab X
c6b2dc34 76@item Electronic Arts Multimedia @tab @tab X
d698c5d3 77 @tab Used in various EA games; files have extensions like WVE and UV2.
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78@item FFM (FFserver live feed) @tab X @tab X
79@item Flash (SWF) @tab X @tab X
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80@item Flash 9 (AVM2) @tab X @tab X
81 @tab Only embedded audio is decoded.
82@item FLI/FLC/FLX animation @tab @tab X
d698c5d3 83 @tab .fli/.flc files
c6b2dc34 84@item FLV @tab X @tab X
d698c5d3 85 @tab Macromedia Flash video files
39271be4 86@item framecrc testing format @tab X @tab
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87@item FunCom ISS @tab @tab X
88 @tab Audio format used in various games from FunCom like The Longest Journey.
39271be4 89@item GIF Animation @tab X @tab
c6b2dc34 90@item GXF @tab X @tab X
d698c5d3 91 @tab General eXchange Format SMPTE 360M, used by Thomson Grass Valley
64c2f20a 92 playout servers.
76ec3939 93@item id Cinematic @tab @tab X
d698c5d3 94 @tab Used in Quake II.
76ec3939 95@item id RoQ @tab X @tab X
d698c5d3 96 @tab Used in Quake III, Jedi Knight 2, other computer games.
c6b2dc34 97@item IFF @tab @tab X
d698c5d3 98 @tab Interchange File Format
c6b2dc34 99@item Interplay MVE @tab @tab X
d698c5d3 100 @tab Format used in various Interplay computer games.
c6b2dc34 101@item LMLM4 @tab @tab X
d698c5d3 102 @tab Used by Linux Media Labs MPEG-4 PCI boards
64c2f20a 103@item Matroska @tab X @tab X
39271be4 104@item Matroska audio @tab X @tab
913c3e2c 105@item MAXIS XA @tab @tab X
d698c5d3 106 @tab Used in Sim City 3000; file extension .xa.
64c2f20a 107@item Monkey's Audio @tab @tab X
822cc8f7 108@item Motion Pixels MVI @tab @tab X
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109@item MOV/QuickTime/MP4 @tab X @tab X
110 @tab 3GP, 3GP2, PSP, iPod variants supported
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111@item MP2 @tab X @tab
112@item MP3 @tab X @tab
c6b2dc34 113@item MPEG audio @tab X @tab X
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114@item MPEG-1 System @tab X @tab X
115 @tab muxed audio and video, VCD format supported
116@item MPEG-PS (program stream) @tab X @tab X
117 @tab also known as @code{VOB} file, SVCD and DVD format supported
118@item MPEG-TS (transport stream) @tab X @tab X
d698c5d3 119 @tab also known as DVB Transport Stream
c6b2dc34 120@item MPEG-4 @tab X @tab X
d698c5d3 121 @tab MPEG-4 is a variant of QuickTime.
39271be4 122@item MIME multipart JPEG @tab X @tab
bac4c85c 123@item MSN TCP webcam @tab @tab X
d698c5d3 124 @tab Used by MSN Messenger webcam streams.
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125@item MTV @tab @tab X
126@item Musepack @tab @tab X
127@item Musepack SV8 @tab @tab X
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128@item Material eXchange Format (MXF) @tab X @tab X
129 @tab SMPTE 377M, used by D-Cinema, broadcast industry.
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130@item Material eXchange Format (MXF), D-10 Mapping @tab X @tab X
131 @tab SMPTE 386M, D-10/IMX Mapping.
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132@item NC camera feed @tab @tab X
133 @tab NC (AVIP NC4600) camera streams
134@item Nullsoft Streaming Video @tab @tab X
39271be4 135@item NuppelVideo @tab @tab X
c6b2dc34 136@item NUT @tab X @tab X
d698c5d3 137 @tab NUT Open Container Format
39271be4 138@item Ogg @tab X @tab X
913c3e2c 139@item TechnoTrend PVA @tab @tab X
d698c5d3 140 @tab Used by TechnoTrend DVB PCI boards.
43dedc1e 141@item raw ADTS (AAC) @tab X @tab X
76ec3939 142@item raw AC-3 @tab X @tab X
adc5abf7 143@item raw Chinese AVS video @tab @tab X
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144@item raw CRI ADX @tab X @tab X
145@item raw Dirac @tab X @tab X
146@item raw DNxHD @tab X @tab X
147@item raw DTS @tab X @tab X
148@item raw E-AC-3 @tab X @tab X
149@item raw FLAC @tab X @tab X
150@item raw GSM @tab @tab X
151@item raw H.261 @tab X @tab X
152@item raw H.263 @tab X @tab X
153@item raw H.264 @tab X @tab X
154@item raw Ingenient MJPEG @tab @tab X
76ec3939 155@item raw MJPEG @tab X @tab X
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156@item raw MLP @tab @tab X
157@item raw MPEG @tab @tab X
158@item raw MPEG-1 @tab @tab X
159@item raw MPEG-2 @tab @tab X
160@item raw MPEG-4 @tab X @tab X
161@item raw NULL @tab X @tab
81b55ee5 162@item raw video @tab X @tab X
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163@item raw id RoQ @tab X @tab
164@item raw Shorten @tab @tab X
165@item raw VC-1 @tab @tab X
166@item raw PCM A-law @tab X @tab X
167@item raw PCM mu-law @tab X @tab X
168@item raw PCM signed 8 bit @tab X @tab X
169@item raw PCM signed 16 bit big-endian @tab X @tab X
170@item raw PCM signed 16 bit little-endian @tab X @tab X
171@item raw PCM signed 24 bit big-endian @tab X @tab X
172@item raw PCM signed 24 bit little-endian @tab X @tab X
173@item raw PCM signed 32 bit big-endian @tab X @tab X
174@item raw PCM signed 32 bit little-endian @tab X @tab X
175@item raw PCM unsigned 8 bit @tab X @tab X
176@item raw PCM unsigned 16 bit big-endian @tab X @tab X
177@item raw PCM unsigned 16 bit little-endian @tab X @tab X
178@item raw PCM unsigned 24 bit big-endian @tab X @tab X
179@item raw PCM unsigned 24 bit little-endian @tab X @tab X
180@item raw PCM unsigned 32 bit big-endian @tab X @tab X
181@item raw PCM unsigned 32 bit little-endian @tab X @tab X
182@item raw PCM floating-point 32 bit big-endian @tab X @tab X
183@item raw PCM floating-point 32 bit little-endian @tab X @tab X
184@item raw PCM floating-point 64 bit big-endian @tab X @tab X
185@item raw PCM floating-point 64 bit little-endian @tab X @tab X
39271be4 186@item RDT @tab @tab X
913c3e2c 187@item REDCODE R3D @tab @tab X
7eb68edb 188 @tab File format used by RED Digital cameras, contains JPEG 2000 frames and PCM audio.
64c2f20a 189@item RealMedia @tab X @tab X
39271be4 190@item Redirector @tab @tab X
913c3e2c 191@item Renderware TeXture Dictionary @tab @tab X
c6b2dc34 192@item RL2 @tab @tab X
d698c5d3 193 @tab Audio and video format used in some games by Entertainment Software Partners.
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194@item RPL/ARMovie @tab @tab X
195@item RTP @tab @tab X
196@item RTSP @tab @tab X
197@item SDP @tab @tab X
c6b2dc34 198@item Sega FILM/CPK @tab @tab X
d698c5d3 199 @tab Used in many Sega Saturn console games.
913c3e2c 200@item Sierra SOL @tab @tab X
d698c5d3 201 @tab .sol files used in Sierra Online games.
c6b2dc34 202@item Sierra VMD @tab @tab X
d698c5d3 203 @tab Used in Sierra CD-ROM games.
c6b2dc34 204@item Smacker @tab @tab X
d698c5d3 205 @tab Multimedia format used by many games.
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206@item Sony OpenMG (OMA) @tab @tab X
207 @tab Audio format used in Sony Sonic Stage and Sony Vegas.
208@item Sony PlayStation STR @tab @tab X
64c2f20a 209@item SUN AU format @tab X @tab X
c6b2dc34 210@item THP @tab @tab X
d698c5d3 211 @tab Used on the Nintendo GameCube.
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212@item Tiertex Limited SEQ @tab @tab X
213 @tab Tiertex .seq files used in the DOS CD-ROM version of the game Flashback.
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214@item True Audio @tab @tab X
215@item VC-1 test bitstream @tab X @tab X
c6b2dc34 216@item WAV @tab X @tab X
39271be4 217@item WavPack @tab @tab X
913c3e2c 218@item Wing Commander III movie @tab @tab X
d698c5d3 219 @tab Multimedia format used in Origin's Wing Commander III computer game.
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220@item Westwood Studios audio @tab @tab X
221 @tab Multimedia format used in Westwood Studios games.
222@item Westwood Studios VQA @tab @tab X
223 @tab Multimedia format used in Westwood Studios games.
39271be4 224@item YUV4MPEG pipe @tab X @tab X
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225@end multitable
226
227@code{X} means that encoding (resp. decoding) is supported.
228
229@section Image Formats
230
231FFmpeg can read and write images for each frame of a video sequence. The
232following image formats are supported:
233
234@multitable @columnfractions .4 .1 .1 .4
b3de4544 235@item Name @tab Encoding @tab Decoding @tab Comments
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DV
236@item .Y.U.V @tab X @tab X
237 @tab one raw file per component
238@item animated GIF @tab X @tab X
239 @tab Only uncompressed GIFs are generated.
240@item JPEG @tab X @tab X
241 @tab Progressive JPEG is not supported.
242@item JPEG 2000 @tab @tab E
243 @tab decoding supported through external library libopenjpeg
244@item PAM @tab X @tab X
245 @tab PAM is a PNM extension with alpha support.
246@item PCX @tab @tab X
247 @tab PC Paintbrush
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248@item PGM @tab X @tab X
249 @tab Portable GrayMap image
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250@item PGMYUV @tab X @tab X
251 @tab PGM with U and V components in YUV 4:2:0
252@item PNG @tab X @tab X
253 @tab 2/4 bpp not supported yet
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DV
254@item PPM @tab X @tab X
255 @tab Portable PixelMap image
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256@item PTX @tab @tab X
257 @tab V.Flash PTX format
258@item RAS @tab @tab X
259 @tab Sun Rasterfile
260@item SGI @tab X @tab X
261 @tab SGI RGB image format
262@item Targa @tab @tab X
263 @tab Targa (.TGA) image format
264@item TIFF @tab X @tab X
265 @tab YUV, JPEG and some extension is not supported yet.
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266@end multitable
267
268@code{X} means that encoding (resp. decoding) is supported.
269
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270@code{E} means that support is provided through an external library.
271
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272@section Video Codecs
273
274@multitable @columnfractions .4 .1 .1 .4
b3de4544 275@item Name @tab Encoding @tab Decoding @tab Comments
d66d8b83 276@item 4X Video @tab @tab X
d698c5d3 277 @tab Used in certain computer games.
913c3e2c 278@item American Laser Games MM @tab @tab X
d698c5d3 279 @tab Used in games like Mad Dog McCree.
d66d8b83 280@item AMV @tab @tab X
d698c5d3 281 @tab Used in Chinese MP3 players.
d66d8b83 282@item Apple Animation @tab X @tab X
d698c5d3 283 @tab fourcc: 'rle '
d66d8b83 284@item Apple Graphics @tab @tab X
d698c5d3 285 @tab fourcc: 'smc '
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286@item Apple MJPEG-B @tab @tab X
287@item Apple QuickDraw @tab @tab X
d698c5d3 288 @tab fourcc: qdrw
d66d8b83 289@item Apple Video @tab @tab X
d698c5d3 290 @tab fourcc: rpza
d66d8b83 291@item Asus v1 @tab X @tab X
d698c5d3 292 @tab fourcc: ASV1
d66d8b83 293@item Asus v2 @tab X @tab X
d698c5d3 294 @tab fourcc: ASV2
d66d8b83 295@item ATI VCR1 @tab @tab X
d698c5d3 296 @tab fourcc: VCR1
d66d8b83 297@item ATI VCR2 @tab @tab X
d698c5d3 298 @tab fourcc: VCR2
d66d8b83 299@item Autodesk RLE @tab @tab X
d698c5d3 300 @tab fourcc: AASC
d66d8b83 301@item AVID DNxHD @tab X @tab X
d698c5d3 302 @tab aka SMPTE VC3
bac4c85c 303@item AVS video @tab @tab X
d698c5d3 304 @tab Video encoding used by the Creature Shock game.
d66d8b83 305@item Bethsoft VID @tab @tab X
d698c5d3 306 @tab Used in some games from Bethesda Softworks.
bac4c85c 307@item C93 video @tab @tab X
d698c5d3 308 @tab Codec used in Cyberia game.
d66d8b83 309@item CamStudio @tab @tab X
d698c5d3 310 @tab fourcc: CSCD
bac4c85c 311@item Cin video @tab @tab X
d698c5d3 312 @tab Codec used in Delphine Software games.
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313@item Cinepak @tab @tab X
314@item Cirrus Logic AccuPak @tab @tab X
d698c5d3 315 @tab fourcc: CLJR
d66d8b83 316@item Creative YUV @tab @tab X
d698c5d3 317 @tab fourcc: CYUV
82ced5a9 318@item Dirac @tab E @tab E
360f980b 319 @tab supported through external libdirac/libschroedinger libraries
d66d8b83 320@item Duck TrueMotion v1 @tab @tab X
d698c5d3 321 @tab fourcc: DUCK
d66d8b83 322@item Duck TrueMotion v2 @tab @tab X
d698c5d3 323 @tab fourcc: TM20
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324@item DV @tab X @tab X
325@item DXA Video @tab @tab X
d698c5d3 326 @tab Codec originally used in Feeble Files game.
d66d8b83 327@item Electronic Arts CMV @tab @tab X
d698c5d3 328 @tab Used in NHL 95 game.
cfc78718 329@item Electronic Arts TGV @tab @tab X
42b30357 330@item Electronic Arts TGQ @tab @tab X
d8964f3a 331@item Electronic Arts TQI @tab @tab X
d66d8b83 332@item FFmpeg Video 1 @tab X @tab X
d698c5d3 333 @tab experimental lossless codec (fourcc: FFV1)
d66d8b83 334@item Flash Screen Video @tab X @tab X
d698c5d3 335 @tab fourcc: FSV1
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336@item FLIC video @tab @tab X
337@item FLV @tab X @tab X
d698c5d3 338 @tab Sorenson H.263 used in Flash
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339@item Fraps FPS1 @tab @tab X
340@item H.261 @tab X @tab X
341@item H.263(+) @tab X @tab X
d698c5d3 342 @tab also known as RealVideo 1.0
82ced5a9 343@item H.264 @tab E @tab X
360f980b 344 @tab encoding supported through external library libx264
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345@item HuffYUV @tab X @tab X
346@item IBM Ultimotion @tab @tab X
d698c5d3 347 @tab fourcc: ULTI
bac4c85c 348@item id Cinematic video @tab @tab X
d698c5d3 349 @tab Used in Quake II.
d66d8b83 350@item id RoQ @tab X @tab X
d698c5d3 351 @tab Used in Quake III, Jedi Knight 2, other computer games.
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352@item Intel Indeo 3 @tab @tab X
353@item Interplay Video @tab @tab X
d698c5d3 354 @tab Used in Interplay .MVE files.
d66d8b83 355@item JPEG-LS @tab X @tab X
d698c5d3 356 @tab fourcc: MJLS, lossless and near-lossless is supported.
d66d8b83 357@item KMVC @tab @tab X
d698c5d3 358 @tab Codec used in Worms games.
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359@item LOCO @tab @tab X
360@item lossless MJPEG @tab X @tab X
361@item Microsoft RLE @tab @tab X
362@item Microsoft Video-1 @tab @tab X
363@item Mimic @tab @tab X
d698c5d3 364 @tab Used in MSN Messenger Webcam streams.
d66d8b83 365@item Miro VideoXL @tab @tab X
d698c5d3 366 @tab fourcc: VIXL
d66d8b83 367@item MJPEG @tab X @tab X
822cc8f7 368@item Motion Pixels Video @tab @tab X
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369@item MPEG-1 @tab X @tab X
370@item MPEG-2 @tab X @tab X
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371@item MPEG-4 @tab X @tab X
372@item MSMPEG4 V1 @tab X @tab X
373@item MSMPEG4 V2 @tab X @tab X
374@item MSMPEG4 V3 @tab X @tab X
d66d8b83 375@item MSZH @tab @tab X
d698c5d3 376 @tab Part of LCL
d66d8b83 377@item On2 VP3 @tab @tab X
d698c5d3 378 @tab still experimental
d66d8b83 379@item On2 VP5 @tab @tab X
d698c5d3 380 @tab fourcc: VP50
d66d8b83 381@item On2 VP6 @tab @tab X
d698c5d3 382 @tab fourcc: VP60,VP61,VP62
d66d8b83 383@item planar RGB @tab @tab X
d698c5d3 384 @tab fourcc: 8BPS
d66d8b83 385@item QPEG @tab @tab X
d698c5d3 386 @tab fourccs: QPEG, Q1.0, Q1.1
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387@item RealVideo 1.0 @tab X @tab X
388@item RealVideo 2.0 @tab X @tab X
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389@item RealVideo 3.0 @tab @tab X
390 @tab still far from ideal
11c0f9ec 391@item RealVideo 4.0 @tab @tab X
d66d8b83 392@item Renderware TXD @tab @tab X
d698c5d3 393 @tab Texture dictionaries used by the Renderware Engine.
d66d8b83 394@item RTjpeg @tab @tab X
d698c5d3 395 @tab Video encoding used in NuppelVideo files.
bac4c85c 396@item Smacker video @tab @tab X
d698c5d3 397 @tab Video encoding used in Smacker.
d66d8b83 398@item Snow @tab X @tab X
d698c5d3 399 @tab experimental wavelet codec (fourcc: SNOW)
831ec935 400@item Sony PlayStation MDEC @tab @tab X
d66d8b83 401@item Sorenson Video 1 @tab X @tab X
d698c5d3 402 @tab fourcc: SVQ1
d66d8b83 403@item Sorenson Video 3 @tab @tab X
d698c5d3 404 @tab fourcc: SVQ3
d66d8b83 405@item Sunplus MJPEG @tab @tab X
d698c5d3 406 @tab fourcc: SP5X
d66d8b83 407@item TechSmith Camtasia @tab @tab X
d698c5d3 408 @tab fourcc: TSCC
82ced5a9 409@item Theora @tab E @tab X
360f980b 410 @tab encoding supported through external library libtheora
d66d8b83 411@item THP @tab @tab X
d698c5d3 412 @tab Used on the Nintendo GameCube.
bac4c85c 413@item Tiertex Seq video @tab @tab X
d698c5d3 414 @tab Codec used in DOS CD-ROM FlashBack game.
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415@item VC-1 @tab @tab X
416@item VMD Video @tab @tab X
d698c5d3 417 @tab Used in Sierra VMD files.
d66d8b83 418@item VMware Video @tab @tab X
d698c5d3 419 @tab Codec used in videos captured by VMware.
d0e1cd3d 420@item Westwood VQA @tab @tab X
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421@item Winnov WNV1 @tab @tab X
422@item WMV7 @tab X @tab X
423@item WMV8 @tab X @tab X
424@item WMV9 @tab @tab X
d698c5d3 425 @tab not completely working
d66d8b83 426@item Xan/WC3 @tab @tab X
d698c5d3 427 @tab Used in Wing Commander III .MVE files.
39271be4 428@item YAMAHA SMAF @tab X @tab X
d66d8b83 429@item ZLIB @tab X @tab X
d698c5d3 430 @tab part of LCL, encoder experimental
d66d8b83 431@item ZMBV @tab X @tab X
d698c5d3 432 @tab Encoder works only in PAL8.
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433@end multitable
434
435@code{X} means that encoding (resp. decoding) is supported.
436
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437@code{E} means that support is provided through an external library.
438
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439@section Audio Codecs
440
485ec4f1 441@multitable @columnfractions .4 .1 .1 .4
b3de4544 442@item Name @tab Encoding @tab Decoding @tab Comments
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443@item 4X IMA ADPCM @tab @tab X
444@item 8SVX audio @tab @tab X
82ced5a9 445@item AAC @tab E @tab X
360f980b 446 @tab encoding supported through external library libfaac
16d81b27 447@item AC-3 @tab IX @tab IX
82ced5a9 448@item AMR-NB @tab E @tab E
360f980b 449 @tab supported through external library libamrnb
82ced5a9 450@item AMR-WB @tab E @tab E
360f980b 451 @tab supported through external library libamrwb
16d81b27 452@item AMV IMA ADPCM @tab @tab X
d698c5d3 453 @tab Used in AMV files
833e90dd 454@item Apple lossless audio @tab X @tab X
d698c5d3 455 @tab QuickTime fourcc 'alac'
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456@item Apple MACE 3 @tab @tab X
457@item Apple MACE 6 @tab @tab X
458@item ATRAC 3 @tab @tab X
459@item CD-ROM XA ADPCM @tab @tab X
bac4c85c 460@item Cin audio @tab @tab X
d698c5d3 461 @tab Codec used in Delphine Software International games.
16d81b27 462@item Creative ADPCM @tab @tab X
d698c5d3 463 @tab 16 -> 4, 8 -> 4, 8 -> 3, 8 -> 2
16d81b27 464@item CRI ADX ADPCM @tab X @tab X
d698c5d3 465 @tab Used in Sega Dreamcast games.
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466@item DSP Group TrueSpeech @tab @tab X
467@item DTS Coherent Audio @tab @tab X
468@item Duck DK3 IMA ADPCM @tab @tab X
d698c5d3 469 @tab Used in some Sega Saturn console games.
16d81b27 470@item Duck DK4 IMA ADPCM @tab @tab X
d698c5d3 471 @tab Used in some Sega Saturn console games.
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472@item DV audio @tab @tab X
473@item Electronic Arts ADPCM @tab @tab X
d698c5d3 474 @tab Used in various EA titles.
44723c84 475@item Enhanced AC-3 @tab @tab X
9a584db4 476@item FLAC lossless audio @tab IX @tab X
16d81b27 477@item G.726 ADPCM @tab X @tab X
82ced5a9 478@item GSM @tab E @tab E
3f33271a 479 @tab supported through external library libgsm
82ced5a9 480@item GSM_MS @tab E @tab E
3f33271a 481 @tab supported through external library libgsm
16d81b27 482@item id RoQ DPCM @tab X @tab X
d698c5d3 483 @tab Used in Quake III, Jedi Knight 2, other computer games.
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484@item Intel Music Coder @tab @tab X
485@item Interplay MVE DPCM @tab @tab X
d698c5d3 486 @tab Used in various Interplay computer games.
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487@item ISS IMA ADPCM @tab @tab X
488 @tab Used in FunCom games.
16d81b27 489@item MAXIS EA ADPCM @tab @tab X
d698c5d3 490 @tab Used in Sim City 3000.
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491@item Microsoft ADPCM @tab X @tab X
492@item MLP/TrueHD @tab @tab X
d698c5d3 493 @tab Used in DVD-Audio and Blu-Ray discs.
16d81b27 494@item Monkey's Audio @tab @tab X
d698c5d3 495 @tab Only versions 3.97-3.99 are supported.
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496@item MPEG audio layer 3 @tab E @tab IX
497 @tab encoding supported through external library LAME
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498@item MPEG audio layer 2 @tab IX @tab IX
499@item MS IMA ADPCM @tab X @tab X
500@item Musepack @tab @tab X
d698c5d3 501 @tab SV7 and SV8 are supported.
755ba886 502@item Nellymoser ASAO @tab X @tab X
73b458e3 503@item QCELP / PureVoice @tab @tab X
16d81b27 504@item Qdesign QDM2 @tab @tab X
d698c5d3 505 @tab There are still some distortions.
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506@item QT IMA ADPCM @tab X @tab X
507@item RA144 @tab @tab X
d698c5d3 508 @tab Real 14400 bit/s codec
16d81b27 509@item RA288 @tab @tab X
d698c5d3 510 @tab Real 28800 bit/s codec
575a5bf2 511@item RADnet @tab IX @tab IX
a692130f 512 @tab Real low bitrate AC-3 codec
16d81b27 513@item Real COOK @tab @tab X
d698c5d3 514 @tab All versions except 5.1 are supported.
bac4c85c 515@item Shorten @tab @tab X
16d81b27 516@item Sierra Online DPCM @tab @tab X
d698c5d3 517 @tab Used in Sierra Online game audio files.
bac4c85c 518@item Smacker audio @tab @tab X
16d81b27 519@item SMJPEG IMA ADPCM @tab @tab X
d698c5d3 520 @tab Used in certain Loki game ports.
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521@item Sonic @tab X @tab X
522 @tab experimental codec
523@item Sonic lossless @tab X @tab X
524 @tab experimental codec
82ced5a9 525@item Speex @tab @tab E
360f980b 526 @tab supported through external library libspeex
16d81b27 527@item THP ADPCM @tab @tab X
d698c5d3 528 @tab Used on the Nintendo GameCube.
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529@item True Audio (TTA) @tab @tab X
530@item Vorbis @tab X @tab X
bac4c85c 531@item WavPack @tab @tab X
16d81b27 532@item Westwood Studios IMA ADPCM @tab @tab X
d698c5d3 533 @tab Used in Westwood Studios games like Command and Conquer.
bac4c85c 534@item WMA v1/v2 @tab X @tab X
16d81b27 535@item Xan DPCM @tab @tab X
d698c5d3 536 @tab Used in Origin's Wing Commander IV AVI files.
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537@end multitable
538
539@code{X} means that encoding (resp. decoding) is supported.
540
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541@code{E} means that support is provided through an external library.
542
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543@code{I} means that an integer-only version is available, too (ensures high
544performance on systems without hardware floating point support).
545
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546@section Subtitle Formats
547
485ec4f1 548@multitable @columnfractions .4 .1 .1 .1 .1 .1
9afc2917 549@item Name @tab Muxing @tab Demuxing @tab Encoding @tab Decoding
913c3e2c 550@item SSA/ASS @tab X @tab X
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551@item DVB @tab X @tab X @tab X @tab X
552@item DVD @tab X @tab X @tab X @tab X
553@item XSUB @tab @tab @tab @tab X
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554@end multitable
555
556@code{X} means that the feature is supported.
557
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558@section Network Protocols
559
560@multitable @columnfractions .4 .1 .1 .1 .1 .1
561@item Name @tab Support
562@item file @tab X
563@item Gopher @tab X
564@item HTTP @tab X
565@item pipe @tab X
566@item RTP @tab X
567@item TCP @tab X
568@item UDP @tab X
569@end multitable
570
571@code{X} means that the protocol is supported.
572
573
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574@chapter Platform Specific information
575
576@section BSD
577
578BSD make will not build FFmpeg, you need to install and use GNU Make
579(@file{gmake}).
580
581@section Windows
582
46a845d0 583To get help and instructions for building FFmpeg under Windows, check out
d0e1cd3d 584the FFmpeg Windows Help Forum at
ab5ce4ae 585@url{http://ffmpeg.arrozcru.org/}.
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586
587@subsection Native Windows compilation
588
c1989552 589FFmpeg can be built to run natively on Windows using the MinGW tools. Install
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590the latest versions of MSYS and MinGW from @url{http://www.mingw.org/}.
591You can find detailed installation
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592instructions in the download section and the FAQ.
593
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594FFmpeg does not build out-of-the-box with the packages the automated MinGW
595installer provides. It also requires coreutils to be installed and many other
596packages updated to the latest version. The minimum version for some packages
597are listed below:
598
599@itemize
600@item bash 3.1
601@item msys-make 3.81-2 (note: not mingw32-make)
2014b51c 602@item w32api 3.13
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603@item mingw-runtime 3.15
604@end itemize
605
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606You will also need to pass @code{-fno-common} to the compiler to work around
607a GCC bug (see @url{http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37216}).
608
c1989552 609Within the MSYS shell, configure and make with:
d0e1cd3d 610
c1989552 611@example
0f898714 612./configure --enable-memalign-hack --extra-cflags=-fno-common
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613make
614make install
615@end example
d0e1cd3d 616
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617This will install @file{ffmpeg.exe} along with many other development files
618to @file{/usr/local}. You may specify another install path using the
619@code{--prefix} option in @file{configure}.
d0e1cd3d 620
c1989552 621Notes:
d0e1cd3d 622
c1989552 623@itemize
d0e1cd3d 624
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625@item In order to compile vhooks, you must have a POSIX-compliant libdl in
626your MinGW system. Get dlfcn-win32 from
627@url{http://code.google.com/p/dlfcn-win32}.
d0e1cd3d 628
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629@item In order to compile FFplay, you must have the MinGW development library
630of SDL. Get it from @url{http://www.libsdl.org}.
631Edit the @file{bin/sdl-config} script so that it points to the correct prefix
632where SDL was installed. Verify that @file{sdl-config} can be launched from
633the MSYS command line.
d0e1cd3d 634
d0e1cd3d 635@item By using @code{./configure --enable-shared} when configuring FFmpeg,
c1989552 636you can build libavutil, libavcodec and libavformat as DLLs.
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637
638@end itemize
639
c1989552 640@subsection Microsoft Visual C++ compatibility
d0e1cd3d 641
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642As stated in the FAQ, FFmpeg will not compile under MSVC++. However, if you
643want to use the libav* libraries in your own applications, you can still
644compile those applications using MSVC++. But the libav* libraries you link
645to @emph{must} be built with MinGW. However, you will not be able to debug
646inside the libav* libraries, since MSVC++ does not recognize the debug
647symbols generated by GCC.
648We strongly recommend you to move over from MSVC++ to MinGW tools.
d0e1cd3d 649
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650This description of how to use the FFmpeg libraries with MSVC++ is based on
651Microsoft Visual C++ 2005 Express Edition. If you have a different version,
652you might have to modify the procedures slightly.
d0e1cd3d 653
c1989552 654@subsubsection Using static libraries
d0e1cd3d 655
c1989552 656Assuming you have just built and installed FFmpeg in @file{/usr/local}.
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657
658@enumerate
659
660@item Create a new console application ("File / New / Project") and then
661select "Win32 Console Application". On the appropriate page of the
662Application Wizard, uncheck the "Precompiled headers" option.
663
664@item Write the source code for your application, or, for testing, just
665copy the code from an existing sample application into the source file
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666that MSVC++ has already created for you. For example, you can copy
667@file{output_example.c} from the FFmpeg distribution.
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668
669@item Open the "Project / Properties" dialog box. In the "Configuration"
670combo box, select "All Configurations" so that the changes you make will
671affect both debug and release builds. In the tree view on the left hand
672side, select "C/C++ / General", then edit the "Additional Include
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673Directories" setting to contain the path where the FFmpeg includes were
674installed (i.e. @file{c:\msys\1.0\local\include}).
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675Do not add MinGW's include directory here, or the include files will
676conflict with MSVC's.
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677
678@item Still in the "Project / Properties" dialog box, select
679"Linker / General" from the tree view and edit the
680"Additional Library Directories" setting to contain the @file{lib}
681directory where FFmpeg was installed (i.e. @file{c:\msys\1.0\local\lib}),
682the directory where MinGW libs are installed (i.e. @file{c:\mingw\lib}),
683and the directory where MinGW's GCC libs are installed
684(i.e. @file{C:\mingw\lib\gcc\mingw32\4.2.1-sjlj}). Then select
685"Linker / Input" from the tree view, and add the files @file{libavformat.a},
686@file{libavcodec.a}, @file{libavutil.a}, @file{libmingwex.a},
687@file{libgcc.a}, and any other libraries you used (i.e. @file{libz.a})
688to the end of "Additional Dependencies".
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689
690@item Now, select "C/C++ / Code Generation" from the tree view. Select
691"Debug" in the "Configuration" combo box. Make sure that "Runtime
692Library" is set to "Multi-threaded Debug DLL". Then, select "Release" in
693the "Configuration" combo box and make sure that "Runtime Library" is
694set to "Multi-threaded DLL".
695
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696@item Click "OK" to close the "Project / Properties" dialog box.
697
698@item MSVC++ lacks some C99 header files that are fundamental for FFmpeg.
699Get msinttypes from @url{http://code.google.com/p/msinttypes/downloads/list}
700and install it in MSVC++'s include directory
701(i.e. @file{C:\Program Files\Microsoft Visual Studio 8\VC\include}).
702
703@item MSVC++ also does not understand the @code{inline} keyword used by
704FFmpeg, so you must add this line before @code{#include}ing libav*:
705@example
706#define inline _inline
707@end example
708
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709@item Build your application, everything should work.
710
711@end enumerate
712
713@subsubsection Using shared libraries
714
715This is how to create DLL and LIB files that are compatible with MSVC++:
716
717@enumerate
718
719@item Add a call to @file{vcvars32.bat} (which sets up the environment
720variables for the Visual C++ tools) as the first line of @file{msys.bat}.
721The standard location for @file{vcvars32.bat} is
722@file{C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat},
723and the standard location for @file{msys.bat} is @file{C:\msys\1.0\msys.bat}.
724If this corresponds to your setup, add the following line as the first line
725of @file{msys.bat}:
726
727@example
728call "C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat"
729@end example
730
731Alternatively, you may start the @file{Visual Studio 2005 Command Prompt},
732and run @file{c:\msys\1.0\msys.bat} from there.
733
734@item Within the MSYS shell, run @code{lib.exe}. If you get a help message
735from @file{Microsoft (R) Library Manager}, this means your environment
736variables are set up correctly, the @file{Microsoft (R) Library Manager}
737is on the path and will be used by FFmpeg to create
738MSVC++-compatible import libraries.
739
740@item Build FFmpeg with
741
742@example
743./configure --enable-shared --enable-memalign-hack
744make
745make install
746@end example
747
748Your install path (@file{/usr/local/} by default) should now have the
749necessary DLL and LIB files under the @file{bin} directory.
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750
751@end enumerate
752
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753To use those files with MSVC++, do the same as you would do with
754the static libraries, as described above. But in Step 4,
755you should only need to add the directory where the LIB files are installed
756(i.e. @file{c:\msys\usr\local\bin}). This is not a typo, the LIB files are
757installed in the @file{bin} directory. And instead of adding @file{libxx.a}
758files, you should add @file{avcodec.lib}, @file{avformat.lib}, and
759@file{avutil.lib}. There should be no need for @file{libmingwex.a},
760@file{libgcc.a}, and @file{wsock32.lib}, nor any other external library
761statically linked into the DLLs. The @file{bin} directory contains a bunch
762of DLL files, but the ones that are actually used to run your application
763are the ones with a major version number in their filenames
764(i.e. @file{avcodec-51.dll}).
765
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766@subsection Cross compilation for Windows with Linux
767
768You must use the MinGW cross compilation tools available at
769@url{http://www.mingw.org/}.
770
771Then configure FFmpeg with the following options:
772@example
773./configure --target-os=mingw32 --cross-prefix=i386-mingw32msvc-
774@end example
775(you can change the cross-prefix according to the prefix chosen for the
776MinGW tools).
777
778Then you can easily test FFmpeg with Wine
779(@url{http://www.winehq.com/}).
780
781@subsection Compilation under Cygwin
782
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783The main issue with the 1.5.x Cygwin versions is that newlib, its C library,
784does not contain llrint(). You need to upgrade to the unstable 1.7.x versions,
785or leverage the implementation in MinGW (as explained below).
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786
787Just install your Cygwin with all the "Base" packages, plus the
788following "Devel" ones:
789@example
f496ab12 790binutils, gcc-core, make, subversion, mingw-runtime, diffutils
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791@end example
792
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793The experimental gcc4 package is still buggy, hence please
794use the official gcc 3.4.4 or a 4.2.x compiled from source by yourself.
795
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796Install the current binutils-20080624-2 as they work fine (the old
797binutils-20060709-1 proved buggy on shared builds).
d0e1cd3d 798
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799Then create a small library that just contains llrint():
800
801@example
802ar x /usr/lib/mingw/libmingwex.a llrint.o
803ar cq /usr/local/lib/libllrint.a llrint.o
804@end example
805
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806Then run
807
808@example
29c3d42b 809./configure --enable-static --disable-shared --extra-ldflags='-L /usr/local/lib' --extra-libs='-l llrint'
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810@end example
811
812to make a static build or
813
814@example
29c3d42b 815./configure --enable-shared --disable-static --extra-ldflags='-L /usr/local/lib' --extra-libs='-l llrint'
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816@end example
817
818to build shared libraries.
819
820If you want to build FFmpeg with additional libraries, download Cygwin
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821"Devel" packages for Ogg and Vorbis from any Cygwin packages repository:
822@example
823libogg-devel, libvorbis-devel
824@end example
825
826These library packages are only available from Cygwin Ports
be8497b0 827(@url{http://sourceware.org/cygwinports/}) :
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828
829@example
830yasm, libSDL-devel, libdirac-devel, libfaac-devel, libfaad-devel, libgsm-devel,
831libmp3lame-devel, libschroedinger1.0-devel, speex-devel, libtheora-devel,
832libxvidcore-devel
833@end example
834
835The recommendation for libnut and x264 is to build them from source by
836yourself, as they evolve too quickly for Cygwin Ports to be up to date.
d0e1cd3d 837
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838Cygwin 1.7.x has IPv6 support. You can add IPv6 to Cygwin 1.5.x by means
839of the @code{libgetaddrinfo-devel} package, available at Cygwin Ports.
840
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841@subsection Crosscompilation for Windows under Cygwin
842
843With Cygwin you can create Windows binaries that do not need the cygwin1.dll.
844
845Just install your Cygwin as explained before, plus these additional
846"Devel" packages:
847@example
848gcc-mingw-core, mingw-runtime, mingw-zlib
849@end example
850
851and add some special flags to your configure invocation.
852
853For a static build run
854@example
855./configure --target-os=mingw32 --enable-memalign-hack --enable-static --disable-shared --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
856@end example
857
858and for a build with shared libraries
859@example
860./configure --target-os=mingw32 --enable-memalign-hack --enable-shared --disable-static --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
861@end example
862
863@section BeOS
864
5f757b85 865BeOS support is broken in mysterious ways.
d0e1cd3d 866
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867@section OS/2
868
869For information about compiling FFmpeg on OS/2 see
870@url{http://www.edm2.com/index.php/FFmpeg}.
871
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872@chapter Developers Guide
873
874@section API
875@itemize @bullet
876@item libavcodec is the library containing the codecs (both encoding and
877decoding). Look at @file{libavcodec/apiexample.c} to see how to use it.
878
879@item libavformat is the library containing the file format handling (mux and
880demux code for several formats). Look at @file{ffplay.c} to use it in a
881player. See @file{output_example.c} to use it to generate audio or video
882streams.
883
884@end itemize
885
886@section Integrating libavcodec or libavformat in your program
887
888You can integrate all the source code of the libraries to link them
889statically to avoid any version problem. All you need is to provide a
890'config.mak' and a 'config.h' in the parent directory. See the defines
891generated by ./configure to understand what is needed.
892
893You can use libavcodec or libavformat in your commercial program, but
894@emph{any patch you make must be published}. The best way to proceed is
895to send your patches to the FFmpeg mailing list.
896
897@node Coding Rules
898@section Coding Rules
899
900FFmpeg is programmed in the ISO C90 language with a few additional
901features from ISO C99, namely:
902@itemize @bullet
903@item
904the @samp{inline} keyword;
905@item
906@samp{//} comments;
907@item
908designated struct initializers (@samp{struct s x = @{ .i = 17 @};})
909@item
910compound literals (@samp{x = (struct s) @{ 17, 23 @};})
911@end itemize
912
913These features are supported by all compilers we care about, so we will not
914accept patches to remove their use unless they absolutely do not impair
915clarity and performance.
916
917All code must compile with GCC 2.95 and GCC 3.3. Currently, FFmpeg also
918compiles with several other compilers, such as the Compaq ccc compiler
919or Sun Studio 9, and we would like to keep it that way unless it would
920be exceedingly involved. To ensure compatibility, please do not use any
921additional C99 features or GCC extensions. Especially watch out for:
922@itemize @bullet
923@item
924mixing statements and declarations;
925@item
926@samp{long long} (use @samp{int64_t} instead);
927@item
928@samp{__attribute__} not protected by @samp{#ifdef __GNUC__} or similar;
929@item
930GCC statement expressions (@samp{(x = (@{ int y = 4; y; @})}).
931@end itemize
932
933Indent size is 4.
934The presentation is the one specified by 'indent -i4 -kr -nut'.
935The TAB character is forbidden outside of Makefiles as is any
936form of trailing whitespace. Commits containing either will be
937rejected by the Subversion repository.
938
939The main priority in FFmpeg is simplicity and small code size in order to
940minimize the bug count.
941
942Comments: Use the JavaDoc/Doxygen
943format (see examples below) so that code documentation
944can be generated automatically. All nontrivial functions should have a comment
945above them explaining what the function does, even if it is just one sentence.
946All structures and their member variables should be documented, too.
947@example
948/**
949 * @@file mpeg.c
950 * MPEG codec.
951 * @@author ...
952 */
953
954/**
955 * Summary sentence.
956 * more text ...
957 * ...
958 */
959typedef struct Foobar@{
960 int var1; /**< var1 description */
961 int var2; ///< var2 description
962 /** var3 description */
963 int var3;
964@} Foobar;
965
966/**
967 * Summary sentence.
968 * more text ...
969 * ...
970 * @@param my_parameter description of my_parameter
971 * @@return return value description
972 */
973int myfunc(int my_parameter)
974...
975@end example
976
977fprintf and printf are forbidden in libavformat and libavcodec,
978please use av_log() instead.
979
980Casts should be used only when necessary. Unneeded parentheses
981should also be avoided if they don't make the code easier to understand.
982
983@section Development Policy
984
985@enumerate
986@item
987 Contributions should be licensed under the LGPL 2.1, including an
988 "or any later version" clause, or the MIT license. GPL 2 including
989 an "or any later version" clause is also acceptable, but LGPL is
990 preferred.
991@item
992 You must not commit code which breaks FFmpeg! (Meaning unfinished but
993 enabled code which breaks compilation or compiles but does not work or
994 breaks the regression tests)
995 You can commit unfinished stuff (for testing etc), but it must be disabled
996 (#ifdef etc) by default so it does not interfere with other developers'
997 work.
998@item
999 You do not have to over-test things. If it works for you, and you think it
1000 should work for others, then commit. If your code has problems
1001 (portability, triggers compiler bugs, unusual environment etc) they will be
1002 reported and eventually fixed.
1003@item
1004 Do not commit unrelated changes together, split them into self-contained
1005 pieces. Also do not forget that if part B depends on part A, but A does not
1006 depend on B, then A can and should be committed first and separate from B.
1007 Keeping changes well split into self-contained parts makes reviewing and
1008 understanding them on the commit log mailing list easier. This also helps
1009 in case of debugging later on.
1010 Also if you have doubts about splitting or not splitting, do not hesitate to
1011 ask/discuss it on the developer mailing list.
1012@item
1013 Do not change behavior of the program (renaming options etc) without
1014 first discussing it on the ffmpeg-devel mailing list. Do not remove
1015 functionality from the code. Just improve!
1016
1017 Note: Redundant code can be removed.
1018@item
1019 Do not commit changes to the build system (Makefiles, configure script)
1020 which change behavior, defaults etc, without asking first. The same
1021 applies to compiler warning fixes, trivial looking fixes and to code
1022 maintained by other developers. We usually have a reason for doing things
1023 the way we do. Send your changes as patches to the ffmpeg-devel mailing
1024 list, and if the code maintainers say OK, you may commit. This does not
1025 apply to files you wrote and/or maintain.
1026@item
1027 We refuse source indentation and other cosmetic changes if they are mixed
1028 with functional changes, such commits will be rejected and removed. Every
1029 developer has his own indentation style, you should not change it. Of course
1030 if you (re)write something, you can use your own style, even though we would
1031 prefer if the indentation throughout FFmpeg was consistent (Many projects
1032 force a given indentation style - we do not.). If you really need to make
1033 indentation changes (try to avoid this), separate them strictly from real
1034 changes.
1035
1036 NOTE: If you had to put if()@{ .. @} over a large (> 5 lines) chunk of code,
1037 then either do NOT change the indentation of the inner part within (do not
1038 move it to the right)! or do so in a separate commit
1039@item
1040 Always fill out the commit log message. Describe in a few lines what you
1041 changed and why. You can refer to mailing list postings if you fix a
1042 particular bug. Comments such as "fixed!" or "Changed it." are unacceptable.
1043@item
1044 If you apply a patch by someone else, include the name and email address in
1045 the log message. Since the ffmpeg-cvslog mailing list is publicly
1046 archived you should add some SPAM protection to the email address. Send an
1047 answer to ffmpeg-devel (or wherever you got the patch from) saying that
1048 you applied the patch.
1049@item
1050 When applying patches that have been discussed (at length) on the mailing
1051 list, reference the thread in the log message.
1052@item
1053 Do NOT commit to code actively maintained by others without permission.
1054 Send a patch to ffmpeg-devel instead. If no one answers within a reasonable
1055 timeframe (12h for build failures and security fixes, 3 days small changes,
1056 1 week for big patches) then commit your patch if you think it is OK.
1057 Also note, the maintainer can simply ask for more time to review!
1058@item
1059 Subscribe to the ffmpeg-cvslog mailing list. The diffs of all commits
1060 are sent there and reviewed by all the other developers. Bugs and possible
1061 improvements or general questions regarding commits are discussed there. We
1062 expect you to react if problems with your code are uncovered.
1063@item
1064 Update the documentation if you change behavior or add features. If you are
1065 unsure how best to do this, send a patch to ffmpeg-devel, the documentation
1066 maintainer(s) will review and commit your stuff.
1067@item
1068 Try to keep important discussions and requests (also) on the public
1069 developer mailing list, so that all developers can benefit from them.
1070@item
1071 Never write to unallocated memory, never write over the end of arrays,
1072 always check values read from some untrusted source before using them
1073 as array index or other risky things.
1074@item
1075 Remember to check if you need to bump versions for the specific libav
1076 parts (libavutil, libavcodec, libavformat) you are changing. You need
b98052d5 1077 to change the version integer.
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1078 Incrementing the first component means no backward compatibility to
1079 previous versions (e.g. removal of a function from the public API).
1080 Incrementing the second component means backward compatible change
b98052d5
PR
1081 (e.g. addition of a function to the public API or extension of an
1082 existing data structure).
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1083 Incrementing the third component means a noteworthy binary compatible
1084 change (e.g. encoder bug fix that matters for the decoder).
1085@item
53407b64 1086 Compiler warnings indicate potential bugs or code with bad style. If a type of
9908c1a8
DB
1087 warning always points to correct and clean code, that warning should
1088 be disabled, not the code changed.
1089 Thus the remaining warnings can either be bugs or correct code.
beaa4a91 1090 If it is a bug, the bug has to be fixed. If it is not, the code should
9908c1a8
DB
1091 be changed to not generate a warning unless that causes a slowdown
1092 or obfuscates the code.
d0e1cd3d
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1093@item
1094 If you add a new file, give it a proper license header. Do not copy and
1095 paste it from a random place, use an existing file as template.
1096@end enumerate
1097
1098We think our rules are not too hard. If you have comments, contact us.
1099
1100Note, these rules are mostly borrowed from the MPlayer project.
1101
1102@section Submitting patches
1103
1104First, (@pxref{Coding Rules}) above if you did not yet.
1105
1106When you submit your patch, try to send a unified diff (diff '-up'
1107option). We cannot read other diffs :-)
1108
1109Also please do not submit a patch which contains several unrelated changes.
1110Split it into separate, self-contained pieces. This does not mean splitting
1111file by file. Instead, make the patch as small as possible while still
1112keeping it as a logical unit that contains an individual change, even
1113if it spans multiple files. This makes reviewing your patches much easier
1114for us and greatly increases your chances of getting your patch applied.
1115
1116Run the regression tests before submitting a patch so that you can
1117verify that there are no big problems.
1118
1119Patches should be posted as base64 encoded attachments (or any other
1120encoding which ensures that the patch will not be trashed during
1121transmission) to the ffmpeg-devel mailing list, see
1122@url{http://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel}
1123
1124It also helps quite a bit if you tell us what the patch does (for example
1125'replaces lrint by lrintf'), and why (for example '*BSD isn't C99 compliant
1126and has no lrint()')
1127
1128Also please if you send several patches, send each patch as a separate mail,
1129do not attach several unrelated patches to the same mail.
1130
28ce1839
RP
1131@section New codecs or formats checklist
1132
1133@enumerate
1134@item
1135 Did you use av_cold for codec initialization and close functions?
1136@item
1137 Did you add a long_name under NULL_IF_CONFIG_SMALL to the AVCodec or
1138 AVInputFormat/AVOutputFormat struct?
1139@item
1140 Did you bump the minor version number in @file{avcodec.h} or
1141 @file{avformat.h}?
1142@item
1143 Did you register it in @file{allcodecs.c} or @file{allformats.c}?
1144@item
1145 Did you add the CodecID to @file{avcodec.h}?
1146@item
1147 If it has a fourcc, did you add it to @file{libavformat/riff.c},
1148 even if it is only a decoder?
1149@item
1150 Did you add a rule to compile the appropriate files in the Makefile?
1151 Remember to do this even if you're just adding a format to a file that is
1152 already being compiled by some other rule, like a raw demuxer.
1153@item
1154 Did you add an entry to the table of supported formats or codecs in the
1155 documentation?
1156@item
1157 Did you add an entry in the Changelog?
1158@item
1159 If it depends on a parser or a library, did you add that dependency in
1160 configure?
1161@item
1162 Did you "svn add" the appropriate files before commiting?
1163@end enumerate
1164
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1165@section patch submission checklist
1166
1167@enumerate
1168@item
1169 Do the regression tests pass with the patch applied?
1170@item
2cdba8bf
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1171 Does @code{make checkheaders} pass with the patch applied?
1172@item
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1173 Is the patch a unified diff?
1174@item
1175 Is the patch against latest FFmpeg SVN?
1176@item
1177 Are you subscribed to ffmpeg-dev?
1178 (the list is subscribers only due to spam)
1179@item
1180 Have you checked that the changes are minimal, so that the same cannot be
1181 achieved with a smaller patch and/or simpler final code?
1182@item
1183 If the change is to speed critical code, did you benchmark it?
1184@item
1185 If you did any benchmarks, did you provide them in the mail?
1186@item
1187 Have you checked that the patch does not introduce buffer overflows or
1188 other security issues?
1189@item
63d247ea
DB
1190 Did you test your decoder or demuxer against damaged data? If no, see
1191 tools/trasher and the noise bitstream filter. Your decoder or demuxer
1192 should not crash or end in a (near) infinite loop when fed damaged data.
b885e0db 1193@item
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1194 Is the patch created from the root of the source tree, so it can be
1195 applied with @code{patch -p0}?
1196@item
1197 Does the patch not mix functional and cosmetic changes?
1198@item
1199 Did you add tabs or trailing whitespace to the code? Both are forbidden.
1200@item
1201 Is the patch attached to the email you send?
1202@item
1203 Is the mime type of the patch correct? It should be text/x-diff or
1204 text/x-patch or at least text/plain and not application/octet-stream.
1205@item
1206 If the patch fixes a bug, did you provide a verbose analysis of the bug?
1207@item
1208 If the patch fixes a bug, did you provide enough information, including
1209 a sample, so the bug can be reproduced and the fix can be verified?
1210 Note please do not attach samples >100k to mails but rather provide a
0fa5f24c 1211 URL, you can upload to ftp://upload.ffmpeg.org
d0e1cd3d
DB
1212@item
1213 Did you provide a verbose summary about what the patch does change?
1214@item
1215 Did you provide a verbose explanation why it changes things like it does?
1216@item
1217 Did you provide a verbose summary of the user visible advantages and
1218 disadvantages if the patch is applied?
1219@item
1220 Did you provide an example so we can verify the new feature added by the
1221 patch easily?
1222@item
1223 If you added a new file, did you insert a license header? It should be
1224 taken from FFmpeg, not randomly copied and pasted from somewhere else.
1225@item
1226 You should maintain alphabetical order in alphabetically ordered lists as
1227 long as doing so does not break API/ABI compatibility.
1228@item
1229 Lines with similar content should be aligned vertically when doing so
1230 improves readability.
1231@item
1232 Did you provide a suggestion for a clear commit log message?
1233@end enumerate
1234
1235@section Patch review process
1236
1237All patches posted to ffmpeg-devel will be reviewed, unless they contain a
1238clear note that the patch is not for SVN.
1239Reviews and comments will be posted as replies to the patch on the
1240mailing list. The patch submitter then has to take care of every comment,
1241that can be by resubmitting a changed patch or by discussion. Resubmitted
1242patches will themselves be reviewed like any other patch. If at some point
1243a patch passes review with no comments then it is approved, that can for
1244simple and small patches happen immediately while large patches will generally
1245have to be changed and reviewed many times before they are approved.
1246After a patch is approved it will be committed to the repository.
1247
1248We will review all submitted patches, but sometimes we are quite busy so
1249especially for large patches this can take several weeks.
1250
1251When resubmitting patches, please do not make any significant changes
1252not related to the comments received during review. Such patches will
1253be rejected. Instead, submit significant changes or new features as
1254separate patches.
1255
1256@section Regression tests
1257
1258Before submitting a patch (or committing to the repository), you should at least
1259test that you did not break anything.
1260
1261The regression tests build a synthetic video stream and a synthetic
1262audio stream. These are then encoded and decoded with all codecs or
1263formats. The CRC (or MD5) of each generated file is recorded in a
1264result file. A 'diff' is launched to compare the reference results and
1265the result file.
1266
1267The regression tests then go on to test the FFserver code with a
1268limited set of streams. It is important that this step runs correctly
1269as well.
1270
1271Run 'make test' to test all the codecs and formats.
1272
1273Run 'make fulltest' to test all the codecs, formats and FFserver.
1274
1275[Of course, some patches may change the results of the regression tests. In
1276this case, the reference results of the regression tests shall be modified
1277accordingly].
1278
1279@bye