Integer-only decoding of AC-3 is not supported.
[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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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.
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240@item BMP @tab X @tab X
241 @tab Microsoft BMP image
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242@item JPEG @tab X @tab X
243 @tab Progressive JPEG is not supported.
244@item JPEG 2000 @tab @tab E
245 @tab decoding supported through external library libopenjpeg
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246@item JPEG-LS @tab X @tab X
247@item LJPEG @tab X @tab
248 @tab Lossless JPEG
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249@item PAM @tab X @tab X
250 @tab PAM is a PNM extension with alpha support.
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251@item PBM @tab X @tab X
252 @tab Portable BitMap image
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253@item PCX @tab @tab X
254 @tab PC Paintbrush
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255@item PGM @tab X @tab X
256 @tab Portable GrayMap image
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257@item PGMYUV @tab X @tab X
258 @tab PGM with U and V components in YUV 4:2:0
259@item PNG @tab X @tab X
260 @tab 2/4 bpp not supported yet
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261@item PPM @tab X @tab X
262 @tab Portable PixelMap image
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263@item PTX @tab @tab X
264 @tab V.Flash PTX format
265@item RAS @tab @tab X
266 @tab Sun Rasterfile
267@item SGI @tab X @tab X
268 @tab SGI RGB image format
21d4af5d 269@item Targa @tab X @tab X
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270 @tab Targa (.TGA) image format
271@item TIFF @tab X @tab X
272 @tab YUV, JPEG and some extension is not supported yet.
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273@end multitable
274
275@code{X} means that encoding (resp. decoding) is supported.
276
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277@code{E} means that support is provided through an external library.
278
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279@section Video Codecs
280
281@multitable @columnfractions .4 .1 .1 .4
b3de4544 282@item Name @tab Encoding @tab Decoding @tab Comments
d66d8b83 283@item 4X Video @tab @tab X
d698c5d3 284 @tab Used in certain computer games.
913c3e2c 285@item American Laser Games MM @tab @tab X
d698c5d3 286 @tab Used in games like Mad Dog McCree.
d66d8b83 287@item AMV @tab @tab X
d698c5d3 288 @tab Used in Chinese MP3 players.
d66d8b83 289@item Apple Animation @tab X @tab X
d698c5d3 290 @tab fourcc: 'rle '
d66d8b83 291@item Apple Graphics @tab @tab X
d698c5d3 292 @tab fourcc: 'smc '
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293@item Apple MJPEG-B @tab @tab X
294@item Apple QuickDraw @tab @tab X
d698c5d3 295 @tab fourcc: qdrw
d66d8b83 296@item Apple Video @tab @tab X
d698c5d3 297 @tab fourcc: rpza
d66d8b83 298@item Asus v1 @tab X @tab X
d698c5d3 299 @tab fourcc: ASV1
d66d8b83 300@item Asus v2 @tab X @tab X
d698c5d3 301 @tab fourcc: ASV2
d66d8b83 302@item ATI VCR1 @tab @tab X
d698c5d3 303 @tab fourcc: VCR1
d66d8b83 304@item ATI VCR2 @tab @tab X
d698c5d3 305 @tab fourcc: VCR2
d66d8b83 306@item Autodesk RLE @tab @tab X
d698c5d3 307 @tab fourcc: AASC
d66d8b83 308@item AVID DNxHD @tab X @tab X
d698c5d3 309 @tab aka SMPTE VC3
bac4c85c 310@item AVS video @tab @tab X
d698c5d3 311 @tab Video encoding used by the Creature Shock game.
d66d8b83 312@item Bethsoft VID @tab @tab X
d698c5d3 313 @tab Used in some games from Bethesda Softworks.
bac4c85c 314@item C93 video @tab @tab X
d698c5d3 315 @tab Codec used in Cyberia game.
d66d8b83 316@item CamStudio @tab @tab X
d698c5d3 317 @tab fourcc: CSCD
bac4c85c 318@item Cin video @tab @tab X
d698c5d3 319 @tab Codec used in Delphine Software games.
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320@item Cinepak @tab @tab X
321@item Cirrus Logic AccuPak @tab @tab X
d698c5d3 322 @tab fourcc: CLJR
d66d8b83 323@item Creative YUV @tab @tab X
d698c5d3 324 @tab fourcc: CYUV
82ced5a9 325@item Dirac @tab E @tab E
360f980b 326 @tab supported through external libdirac/libschroedinger libraries
d66d8b83 327@item Duck TrueMotion v1 @tab @tab X
d698c5d3 328 @tab fourcc: DUCK
d66d8b83 329@item Duck TrueMotion v2 @tab @tab X
d698c5d3 330 @tab fourcc: TM20
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331@item DV @tab X @tab X
332@item DXA Video @tab @tab X
d698c5d3 333 @tab Codec originally used in Feeble Files game.
d66d8b83 334@item Electronic Arts CMV @tab @tab X
d698c5d3 335 @tab Used in NHL 95 game.
cfc78718 336@item Electronic Arts TGV @tab @tab X
42b30357 337@item Electronic Arts TGQ @tab @tab X
d8964f3a 338@item Electronic Arts TQI @tab @tab X
d66d8b83 339@item FFmpeg Video 1 @tab X @tab X
d698c5d3 340 @tab experimental lossless codec (fourcc: FFV1)
d66d8b83 341@item Flash Screen Video @tab X @tab X
d698c5d3 342 @tab fourcc: FSV1
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343@item FLIC video @tab @tab X
344@item FLV @tab X @tab X
d698c5d3 345 @tab Sorenson H.263 used in Flash
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346@item Fraps FPS1 @tab @tab X
347@item H.261 @tab X @tab X
348@item H.263(+) @tab X @tab X
d698c5d3 349 @tab also known as RealVideo 1.0
82ced5a9 350@item H.264 @tab E @tab X
360f980b 351 @tab encoding supported through external library libx264
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352@item HuffYUV @tab X @tab X
353@item IBM Ultimotion @tab @tab X
d698c5d3 354 @tab fourcc: ULTI
bac4c85c 355@item id Cinematic video @tab @tab X
d698c5d3 356 @tab Used in Quake II.
d66d8b83 357@item id RoQ @tab X @tab X
d698c5d3 358 @tab Used in Quake III, Jedi Knight 2, other computer games.
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359@item Intel Indeo 3 @tab @tab X
360@item Interplay Video @tab @tab X
d698c5d3 361 @tab Used in Interplay .MVE files.
d66d8b83 362@item JPEG-LS @tab X @tab X
d698c5d3 363 @tab fourcc: MJLS, lossless and near-lossless is supported.
d66d8b83 364@item KMVC @tab @tab X
d698c5d3 365 @tab Codec used in Worms games.
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366@item LOCO @tab @tab X
367@item lossless MJPEG @tab X @tab X
368@item Microsoft RLE @tab @tab X
369@item Microsoft Video-1 @tab @tab X
370@item Mimic @tab @tab X
d698c5d3 371 @tab Used in MSN Messenger Webcam streams.
d66d8b83 372@item Miro VideoXL @tab @tab X
d698c5d3 373 @tab fourcc: VIXL
d66d8b83 374@item MJPEG @tab X @tab X
822cc8f7 375@item Motion Pixels Video @tab @tab X
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376@item MPEG-1 @tab X @tab X
377@item MPEG-2 @tab X @tab X
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378@item MPEG-4 @tab X @tab X
379@item MSMPEG4 V1 @tab X @tab X
380@item MSMPEG4 V2 @tab X @tab X
381@item MSMPEG4 V3 @tab X @tab X
d66d8b83 382@item MSZH @tab @tab X
d698c5d3 383 @tab Part of LCL
d66d8b83 384@item On2 VP3 @tab @tab X
d698c5d3 385 @tab still experimental
d66d8b83 386@item On2 VP5 @tab @tab X
d698c5d3 387 @tab fourcc: VP50
d66d8b83 388@item On2 VP6 @tab @tab X
d698c5d3 389 @tab fourcc: VP60,VP61,VP62
d66d8b83 390@item planar RGB @tab @tab X
d698c5d3 391 @tab fourcc: 8BPS
d66d8b83 392@item QPEG @tab @tab X
d698c5d3 393 @tab fourccs: QPEG, Q1.0, Q1.1
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394@item RealVideo 1.0 @tab X @tab X
395@item RealVideo 2.0 @tab X @tab X
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396@item RealVideo 3.0 @tab @tab X
397 @tab still far from ideal
11c0f9ec 398@item RealVideo 4.0 @tab @tab X
d66d8b83 399@item Renderware TXD @tab @tab X
d698c5d3 400 @tab Texture dictionaries used by the Renderware Engine.
d66d8b83 401@item RTjpeg @tab @tab X
d698c5d3 402 @tab Video encoding used in NuppelVideo files.
bac4c85c 403@item Smacker video @tab @tab X
d698c5d3 404 @tab Video encoding used in Smacker.
d66d8b83 405@item Snow @tab X @tab X
d698c5d3 406 @tab experimental wavelet codec (fourcc: SNOW)
831ec935 407@item Sony PlayStation MDEC @tab @tab X
d66d8b83 408@item Sorenson Video 1 @tab X @tab X
d698c5d3 409 @tab fourcc: SVQ1
d66d8b83 410@item Sorenson Video 3 @tab @tab X
d698c5d3 411 @tab fourcc: SVQ3
d66d8b83 412@item Sunplus MJPEG @tab @tab X
d698c5d3 413 @tab fourcc: SP5X
d66d8b83 414@item TechSmith Camtasia @tab @tab X
d698c5d3 415 @tab fourcc: TSCC
82ced5a9 416@item Theora @tab E @tab X
360f980b 417 @tab encoding supported through external library libtheora
d66d8b83 418@item THP @tab @tab X
d698c5d3 419 @tab Used on the Nintendo GameCube.
bac4c85c 420@item Tiertex Seq video @tab @tab X
d698c5d3 421 @tab Codec used in DOS CD-ROM FlashBack game.
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422@item VC-1 @tab @tab X
423@item VMD Video @tab @tab X
d698c5d3 424 @tab Used in Sierra VMD files.
d66d8b83 425@item VMware Video @tab @tab X
d698c5d3 426 @tab Codec used in videos captured by VMware.
d0e1cd3d 427@item Westwood VQA @tab @tab X
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428@item Winnov WNV1 @tab @tab X
429@item WMV7 @tab X @tab X
430@item WMV8 @tab X @tab X
431@item WMV9 @tab @tab X
d698c5d3 432 @tab not completely working
d66d8b83 433@item Xan/WC3 @tab @tab X
d698c5d3 434 @tab Used in Wing Commander III .MVE files.
39271be4 435@item YAMAHA SMAF @tab X @tab X
d66d8b83 436@item ZLIB @tab X @tab X
d698c5d3 437 @tab part of LCL, encoder experimental
d66d8b83 438@item ZMBV @tab X @tab X
d698c5d3 439 @tab Encoder works only in PAL8.
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440@end multitable
441
442@code{X} means that encoding (resp. decoding) is supported.
443
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444@code{E} means that support is provided through an external library.
445
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446@section Audio Codecs
447
485ec4f1 448@multitable @columnfractions .4 .1 .1 .4
b3de4544 449@item Name @tab Encoding @tab Decoding @tab Comments
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450@item 4X IMA ADPCM @tab @tab X
451@item 8SVX audio @tab @tab X
82ced5a9 452@item AAC @tab E @tab X
360f980b 453 @tab encoding supported through external library libfaac
270fc177 454@item AC-3 @tab X @tab X
82ced5a9 455@item AMR-NB @tab E @tab E
360f980b 456 @tab supported through external library libamrnb
82ced5a9 457@item AMR-WB @tab E @tab E
360f980b 458 @tab supported through external library libamrwb
16d81b27 459@item AMV IMA ADPCM @tab @tab X
d698c5d3 460 @tab Used in AMV files
833e90dd 461@item Apple lossless audio @tab X @tab X
d698c5d3 462 @tab QuickTime fourcc 'alac'
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463@item Apple MACE 3 @tab @tab X
464@item Apple MACE 6 @tab @tab X
465@item ATRAC 3 @tab @tab X
466@item CD-ROM XA ADPCM @tab @tab X
bac4c85c 467@item Cin audio @tab @tab X
d698c5d3 468 @tab Codec used in Delphine Software International games.
16d81b27 469@item Creative ADPCM @tab @tab X
d698c5d3 470 @tab 16 -> 4, 8 -> 4, 8 -> 3, 8 -> 2
16d81b27 471@item CRI ADX ADPCM @tab X @tab X
d698c5d3 472 @tab Used in Sega Dreamcast games.
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473@item DSP Group TrueSpeech @tab @tab X
474@item DTS Coherent Audio @tab @tab X
475@item Duck DK3 IMA ADPCM @tab @tab X
d698c5d3 476 @tab Used in some Sega Saturn console games.
16d81b27 477@item Duck DK4 IMA ADPCM @tab @tab X
d698c5d3 478 @tab Used in some Sega Saturn console games.
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479@item DV audio @tab @tab X
480@item Electronic Arts ADPCM @tab @tab X
d698c5d3 481 @tab Used in various EA titles.
44723c84 482@item Enhanced AC-3 @tab @tab X
9a584db4 483@item FLAC lossless audio @tab IX @tab X
16d81b27 484@item G.726 ADPCM @tab X @tab X
82ced5a9 485@item GSM @tab E @tab E
3f33271a 486 @tab supported through external library libgsm
82ced5a9 487@item GSM_MS @tab E @tab E
3f33271a 488 @tab supported through external library libgsm
16d81b27 489@item id RoQ DPCM @tab X @tab X
d698c5d3 490 @tab Used in Quake III, Jedi Knight 2, other computer games.
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491@item Intel Music Coder @tab @tab X
492@item Interplay MVE DPCM @tab @tab X
d698c5d3 493 @tab Used in various Interplay computer games.
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494@item ISS IMA ADPCM @tab @tab X
495 @tab Used in FunCom games.
16d81b27 496@item MAXIS EA ADPCM @tab @tab X
d698c5d3 497 @tab Used in Sim City 3000.
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498@item Microsoft ADPCM @tab X @tab X
499@item MLP/TrueHD @tab @tab X
d698c5d3 500 @tab Used in DVD-Audio and Blu-Ray discs.
16d81b27 501@item Monkey's Audio @tab @tab X
d698c5d3 502 @tab Only versions 3.97-3.99 are supported.
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503@item MPEG audio layer 3 @tab E @tab IX
504 @tab encoding supported through external library LAME
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505@item MPEG audio layer 2 @tab IX @tab IX
506@item MS IMA ADPCM @tab X @tab X
507@item Musepack @tab @tab X
d698c5d3 508 @tab SV7 and SV8 are supported.
755ba886 509@item Nellymoser ASAO @tab X @tab X
73b458e3 510@item QCELP / PureVoice @tab @tab X
16d81b27 511@item Qdesign QDM2 @tab @tab X
d698c5d3 512 @tab There are still some distortions.
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513@item QT IMA ADPCM @tab X @tab X
514@item RA144 @tab @tab X
d698c5d3 515 @tab Real 14400 bit/s codec
16d81b27 516@item RA288 @tab @tab X
d698c5d3 517 @tab Real 28800 bit/s codec
575a5bf2 518@item RADnet @tab IX @tab IX
a692130f 519 @tab Real low bitrate AC-3 codec
16d81b27 520@item Real COOK @tab @tab X
d698c5d3 521 @tab All versions except 5.1 are supported.
bac4c85c 522@item Shorten @tab @tab X
16d81b27 523@item Sierra Online DPCM @tab @tab X
d698c5d3 524 @tab Used in Sierra Online game audio files.
bac4c85c 525@item Smacker audio @tab @tab X
16d81b27 526@item SMJPEG IMA ADPCM @tab @tab X
d698c5d3 527 @tab Used in certain Loki game ports.
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528@item Sonic @tab X @tab X
529 @tab experimental codec
530@item Sonic lossless @tab X @tab X
531 @tab experimental codec
82ced5a9 532@item Speex @tab @tab E
360f980b 533 @tab supported through external library libspeex
16d81b27 534@item THP ADPCM @tab @tab X
d698c5d3 535 @tab Used on the Nintendo GameCube.
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536@item True Audio (TTA) @tab @tab X
537@item Vorbis @tab X @tab X
bac4c85c 538@item WavPack @tab @tab X
16d81b27 539@item Westwood Studios IMA ADPCM @tab @tab X
d698c5d3 540 @tab Used in Westwood Studios games like Command and Conquer.
bac4c85c 541@item WMA v1/v2 @tab X @tab X
16d81b27 542@item Xan DPCM @tab @tab X
d698c5d3 543 @tab Used in Origin's Wing Commander IV AVI files.
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544@end multitable
545
546@code{X} means that encoding (resp. decoding) is supported.
547
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548@code{E} means that support is provided through an external library.
549
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550@code{I} means that an integer-only version is available, too (ensures high
551performance on systems without hardware floating point support).
552
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553@section Subtitle Formats
554
485ec4f1 555@multitable @columnfractions .4 .1 .1 .1 .1 .1
9afc2917 556@item Name @tab Muxing @tab Demuxing @tab Encoding @tab Decoding
913c3e2c 557@item SSA/ASS @tab X @tab X
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558@item DVB @tab X @tab X @tab X @tab X
559@item DVD @tab X @tab X @tab X @tab X
560@item XSUB @tab @tab @tab @tab X
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561@end multitable
562
563@code{X} means that the feature is supported.
564
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565@section Network Protocols
566
567@multitable @columnfractions .4 .1 .1 .1 .1 .1
568@item Name @tab Support
569@item file @tab X
570@item Gopher @tab X
571@item HTTP @tab X
572@item pipe @tab X
573@item RTP @tab X
574@item TCP @tab X
575@item UDP @tab X
576@end multitable
577
578@code{X} means that the protocol is supported.
579
580
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581@chapter Platform Specific information
582
583@section BSD
584
585BSD make will not build FFmpeg, you need to install and use GNU Make
586(@file{gmake}).
587
588@section Windows
589
46a845d0 590To get help and instructions for building FFmpeg under Windows, check out
d0e1cd3d 591the FFmpeg Windows Help Forum at
ab5ce4ae 592@url{http://ffmpeg.arrozcru.org/}.
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593
594@subsection Native Windows compilation
595
c1989552 596FFmpeg can be built to run natively on Windows using the MinGW tools. Install
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597the latest versions of MSYS and MinGW from @url{http://www.mingw.org/}.
598You can find detailed installation
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599instructions in the download section and the FAQ.
600
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601FFmpeg does not build out-of-the-box with the packages the automated MinGW
602installer provides. It also requires coreutils to be installed and many other
603packages updated to the latest version. The minimum version for some packages
604are listed below:
605
606@itemize
607@item bash 3.1
608@item msys-make 3.81-2 (note: not mingw32-make)
2014b51c 609@item w32api 3.13
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610@item mingw-runtime 3.15
611@end itemize
612
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613You will also need to pass @code{-fno-common} to the compiler to work around
614a GCC bug (see @url{http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37216}).
615
c1989552 616Within the MSYS shell, configure and make with:
d0e1cd3d 617
c1989552 618@example
0f898714 619./configure --enable-memalign-hack --extra-cflags=-fno-common
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620make
621make install
622@end example
d0e1cd3d 623
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624This will install @file{ffmpeg.exe} along with many other development files
625to @file{/usr/local}. You may specify another install path using the
626@code{--prefix} option in @file{configure}.
d0e1cd3d 627
c1989552 628Notes:
d0e1cd3d 629
c1989552 630@itemize
d0e1cd3d 631
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632@item In order to compile vhooks, you must have a POSIX-compliant libdl in
633your MinGW system. Get dlfcn-win32 from
634@url{http://code.google.com/p/dlfcn-win32}.
d0e1cd3d 635
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636@item In order to compile FFplay, you must have the MinGW development library
637of SDL. Get it from @url{http://www.libsdl.org}.
638Edit the @file{bin/sdl-config} script so that it points to the correct prefix
639where SDL was installed. Verify that @file{sdl-config} can be launched from
640the MSYS command line.
d0e1cd3d 641
d0e1cd3d 642@item By using @code{./configure --enable-shared} when configuring FFmpeg,
c1989552 643you can build libavutil, libavcodec and libavformat as DLLs.
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644
645@end itemize
646
c1989552 647@subsection Microsoft Visual C++ compatibility
d0e1cd3d 648
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649As stated in the FAQ, FFmpeg will not compile under MSVC++. However, if you
650want to use the libav* libraries in your own applications, you can still
651compile those applications using MSVC++. But the libav* libraries you link
652to @emph{must} be built with MinGW. However, you will not be able to debug
653inside the libav* libraries, since MSVC++ does not recognize the debug
654symbols generated by GCC.
655We strongly recommend you to move over from MSVC++ to MinGW tools.
d0e1cd3d 656
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657This description of how to use the FFmpeg libraries with MSVC++ is based on
658Microsoft Visual C++ 2005 Express Edition. If you have a different version,
659you might have to modify the procedures slightly.
d0e1cd3d 660
c1989552 661@subsubsection Using static libraries
d0e1cd3d 662
c1989552 663Assuming you have just built and installed FFmpeg in @file{/usr/local}.
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664
665@enumerate
666
667@item Create a new console application ("File / New / Project") and then
668select "Win32 Console Application". On the appropriate page of the
669Application Wizard, uncheck the "Precompiled headers" option.
670
671@item Write the source code for your application, or, for testing, just
672copy the code from an existing sample application into the source file
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673that MSVC++ has already created for you. For example, you can copy
674@file{output_example.c} from the FFmpeg distribution.
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675
676@item Open the "Project / Properties" dialog box. In the "Configuration"
677combo box, select "All Configurations" so that the changes you make will
678affect both debug and release builds. In the tree view on the left hand
679side, select "C/C++ / General", then edit the "Additional Include
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680Directories" setting to contain the path where the FFmpeg includes were
681installed (i.e. @file{c:\msys\1.0\local\include}).
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682Do not add MinGW's include directory here, or the include files will
683conflict with MSVC's.
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684
685@item Still in the "Project / Properties" dialog box, select
686"Linker / General" from the tree view and edit the
687"Additional Library Directories" setting to contain the @file{lib}
688directory where FFmpeg was installed (i.e. @file{c:\msys\1.0\local\lib}),
689the directory where MinGW libs are installed (i.e. @file{c:\mingw\lib}),
690and the directory where MinGW's GCC libs are installed
691(i.e. @file{C:\mingw\lib\gcc\mingw32\4.2.1-sjlj}). Then select
692"Linker / Input" from the tree view, and add the files @file{libavformat.a},
693@file{libavcodec.a}, @file{libavutil.a}, @file{libmingwex.a},
694@file{libgcc.a}, and any other libraries you used (i.e. @file{libz.a})
695to the end of "Additional Dependencies".
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696
697@item Now, select "C/C++ / Code Generation" from the tree view. Select
698"Debug" in the "Configuration" combo box. Make sure that "Runtime
699Library" is set to "Multi-threaded Debug DLL". Then, select "Release" in
700the "Configuration" combo box and make sure that "Runtime Library" is
701set to "Multi-threaded DLL".
702
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703@item Click "OK" to close the "Project / Properties" dialog box.
704
705@item MSVC++ lacks some C99 header files that are fundamental for FFmpeg.
706Get msinttypes from @url{http://code.google.com/p/msinttypes/downloads/list}
707and install it in MSVC++'s include directory
708(i.e. @file{C:\Program Files\Microsoft Visual Studio 8\VC\include}).
709
710@item MSVC++ also does not understand the @code{inline} keyword used by
711FFmpeg, so you must add this line before @code{#include}ing libav*:
712@example
713#define inline _inline
714@end example
715
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716@item Build your application, everything should work.
717
718@end enumerate
719
720@subsubsection Using shared libraries
721
722This is how to create DLL and LIB files that are compatible with MSVC++:
723
724@enumerate
725
726@item Add a call to @file{vcvars32.bat} (which sets up the environment
727variables for the Visual C++ tools) as the first line of @file{msys.bat}.
728The standard location for @file{vcvars32.bat} is
729@file{C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat},
730and the standard location for @file{msys.bat} is @file{C:\msys\1.0\msys.bat}.
731If this corresponds to your setup, add the following line as the first line
732of @file{msys.bat}:
733
734@example
735call "C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat"
736@end example
737
738Alternatively, you may start the @file{Visual Studio 2005 Command Prompt},
739and run @file{c:\msys\1.0\msys.bat} from there.
740
741@item Within the MSYS shell, run @code{lib.exe}. If you get a help message
742from @file{Microsoft (R) Library Manager}, this means your environment
743variables are set up correctly, the @file{Microsoft (R) Library Manager}
744is on the path and will be used by FFmpeg to create
745MSVC++-compatible import libraries.
746
747@item Build FFmpeg with
748
749@example
750./configure --enable-shared --enable-memalign-hack
751make
752make install
753@end example
754
755Your install path (@file{/usr/local/} by default) should now have the
756necessary DLL and LIB files under the @file{bin} directory.
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757
758@end enumerate
759
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760To use those files with MSVC++, do the same as you would do with
761the static libraries, as described above. But in Step 4,
762you should only need to add the directory where the LIB files are installed
763(i.e. @file{c:\msys\usr\local\bin}). This is not a typo, the LIB files are
764installed in the @file{bin} directory. And instead of adding @file{libxx.a}
765files, you should add @file{avcodec.lib}, @file{avformat.lib}, and
766@file{avutil.lib}. There should be no need for @file{libmingwex.a},
767@file{libgcc.a}, and @file{wsock32.lib}, nor any other external library
768statically linked into the DLLs. The @file{bin} directory contains a bunch
769of DLL files, but the ones that are actually used to run your application
770are the ones with a major version number in their filenames
771(i.e. @file{avcodec-51.dll}).
772
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773@subsection Cross compilation for Windows with Linux
774
775You must use the MinGW cross compilation tools available at
776@url{http://www.mingw.org/}.
777
778Then configure FFmpeg with the following options:
779@example
780./configure --target-os=mingw32 --cross-prefix=i386-mingw32msvc-
781@end example
782(you can change the cross-prefix according to the prefix chosen for the
783MinGW tools).
784
785Then you can easily test FFmpeg with Wine
786(@url{http://www.winehq.com/}).
787
788@subsection Compilation under Cygwin
789
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790The main issue with the 1.5.x Cygwin versions is that newlib, its C library,
791does not contain llrint(). You need to upgrade to the unstable 1.7.x versions,
792or leverage the implementation in MinGW (as explained below).
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793
794Just install your Cygwin with all the "Base" packages, plus the
795following "Devel" ones:
796@example
f496ab12 797binutils, gcc-core, make, subversion, mingw-runtime, diffutils
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798@end example
799
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800The experimental gcc4 package is still buggy, hence please
801use the official gcc 3.4.4 or a 4.2.x compiled from source by yourself.
802
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803Install the current binutils-20080624-2 as they work fine (the old
804binutils-20060709-1 proved buggy on shared builds).
d0e1cd3d 805
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806Then create a small library that just contains llrint():
807
808@example
809ar x /usr/lib/mingw/libmingwex.a llrint.o
810ar cq /usr/local/lib/libllrint.a llrint.o
811@end example
812
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813Then run
814
815@example
29c3d42b 816./configure --enable-static --disable-shared --extra-ldflags='-L /usr/local/lib' --extra-libs='-l llrint'
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817@end example
818
819to make a static build or
820
821@example
29c3d42b 822./configure --enable-shared --disable-static --extra-ldflags='-L /usr/local/lib' --extra-libs='-l llrint'
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823@end example
824
825to build shared libraries.
826
827If you want to build FFmpeg with additional libraries, download Cygwin
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828"Devel" packages for Ogg and Vorbis from any Cygwin packages repository:
829@example
830libogg-devel, libvorbis-devel
831@end example
832
833These library packages are only available from Cygwin Ports
be8497b0 834(@url{http://sourceware.org/cygwinports/}) :
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835
836@example
837yasm, libSDL-devel, libdirac-devel, libfaac-devel, libfaad-devel, libgsm-devel,
838libmp3lame-devel, libschroedinger1.0-devel, speex-devel, libtheora-devel,
839libxvidcore-devel
840@end example
841
842The recommendation for libnut and x264 is to build them from source by
843yourself, as they evolve too quickly for Cygwin Ports to be up to date.
d0e1cd3d 844
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845Cygwin 1.7.x has IPv6 support. You can add IPv6 to Cygwin 1.5.x by means
846of the @code{libgetaddrinfo-devel} package, available at Cygwin Ports.
847
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848@subsection Crosscompilation for Windows under Cygwin
849
850With Cygwin you can create Windows binaries that do not need the cygwin1.dll.
851
852Just install your Cygwin as explained before, plus these additional
853"Devel" packages:
854@example
855gcc-mingw-core, mingw-runtime, mingw-zlib
856@end example
857
858and add some special flags to your configure invocation.
859
860For a static build run
861@example
862./configure --target-os=mingw32 --enable-memalign-hack --enable-static --disable-shared --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
863@end example
864
865and for a build with shared libraries
866@example
867./configure --target-os=mingw32 --enable-memalign-hack --enable-shared --disable-static --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
868@end example
869
870@section BeOS
871
5f757b85 872BeOS support is broken in mysterious ways.
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874@section OS/2
875
876For information about compiling FFmpeg on OS/2 see
877@url{http://www.edm2.com/index.php/FFmpeg}.
878
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879@chapter Developers Guide
880
881@section API
882@itemize @bullet
883@item libavcodec is the library containing the codecs (both encoding and
884decoding). Look at @file{libavcodec/apiexample.c} to see how to use it.
885
886@item libavformat is the library containing the file format handling (mux and
887demux code for several formats). Look at @file{ffplay.c} to use it in a
888player. See @file{output_example.c} to use it to generate audio or video
889streams.
890
891@end itemize
892
893@section Integrating libavcodec or libavformat in your program
894
895You can integrate all the source code of the libraries to link them
896statically to avoid any version problem. All you need is to provide a
897'config.mak' and a 'config.h' in the parent directory. See the defines
898generated by ./configure to understand what is needed.
899
900You can use libavcodec or libavformat in your commercial program, but
901@emph{any patch you make must be published}. The best way to proceed is
902to send your patches to the FFmpeg mailing list.
903
904@node Coding Rules
905@section Coding Rules
906
907FFmpeg is programmed in the ISO C90 language with a few additional
908features from ISO C99, namely:
909@itemize @bullet
910@item
911the @samp{inline} keyword;
912@item
913@samp{//} comments;
914@item
915designated struct initializers (@samp{struct s x = @{ .i = 17 @};})
916@item
917compound literals (@samp{x = (struct s) @{ 17, 23 @};})
918@end itemize
919
920These features are supported by all compilers we care about, so we will not
921accept patches to remove their use unless they absolutely do not impair
922clarity and performance.
923
924All code must compile with GCC 2.95 and GCC 3.3. Currently, FFmpeg also
925compiles with several other compilers, such as the Compaq ccc compiler
926or Sun Studio 9, and we would like to keep it that way unless it would
927be exceedingly involved. To ensure compatibility, please do not use any
928additional C99 features or GCC extensions. Especially watch out for:
929@itemize @bullet
930@item
931mixing statements and declarations;
932@item
933@samp{long long} (use @samp{int64_t} instead);
934@item
935@samp{__attribute__} not protected by @samp{#ifdef __GNUC__} or similar;
936@item
937GCC statement expressions (@samp{(x = (@{ int y = 4; y; @})}).
938@end itemize
939
940Indent size is 4.
941The presentation is the one specified by 'indent -i4 -kr -nut'.
942The TAB character is forbidden outside of Makefiles as is any
943form of trailing whitespace. Commits containing either will be
944rejected by the Subversion repository.
945
946The main priority in FFmpeg is simplicity and small code size in order to
947minimize the bug count.
948
949Comments: Use the JavaDoc/Doxygen
950format (see examples below) so that code documentation
951can be generated automatically. All nontrivial functions should have a comment
952above them explaining what the function does, even if it is just one sentence.
953All structures and their member variables should be documented, too.
954@example
955/**
956 * @@file mpeg.c
957 * MPEG codec.
958 * @@author ...
959 */
960
961/**
962 * Summary sentence.
963 * more text ...
964 * ...
965 */
966typedef struct Foobar@{
967 int var1; /**< var1 description */
968 int var2; ///< var2 description
969 /** var3 description */
970 int var3;
971@} Foobar;
972
973/**
974 * Summary sentence.
975 * more text ...
976 * ...
977 * @@param my_parameter description of my_parameter
978 * @@return return value description
979 */
980int myfunc(int my_parameter)
981...
982@end example
983
984fprintf and printf are forbidden in libavformat and libavcodec,
985please use av_log() instead.
986
987Casts should be used only when necessary. Unneeded parentheses
988should also be avoided if they don't make the code easier to understand.
989
990@section Development Policy
991
992@enumerate
993@item
994 Contributions should be licensed under the LGPL 2.1, including an
995 "or any later version" clause, or the MIT license. GPL 2 including
996 an "or any later version" clause is also acceptable, but LGPL is
997 preferred.
998@item
999 You must not commit code which breaks FFmpeg! (Meaning unfinished but
1000 enabled code which breaks compilation or compiles but does not work or
1001 breaks the regression tests)
1002 You can commit unfinished stuff (for testing etc), but it must be disabled
1003 (#ifdef etc) by default so it does not interfere with other developers'
1004 work.
1005@item
1006 You do not have to over-test things. If it works for you, and you think it
1007 should work for others, then commit. If your code has problems
1008 (portability, triggers compiler bugs, unusual environment etc) they will be
1009 reported and eventually fixed.
1010@item
1011 Do not commit unrelated changes together, split them into self-contained
1012 pieces. Also do not forget that if part B depends on part A, but A does not
1013 depend on B, then A can and should be committed first and separate from B.
1014 Keeping changes well split into self-contained parts makes reviewing and
1015 understanding them on the commit log mailing list easier. This also helps
1016 in case of debugging later on.
1017 Also if you have doubts about splitting or not splitting, do not hesitate to
1018 ask/discuss it on the developer mailing list.
1019@item
1020 Do not change behavior of the program (renaming options etc) without
1021 first discussing it on the ffmpeg-devel mailing list. Do not remove
1022 functionality from the code. Just improve!
1023
1024 Note: Redundant code can be removed.
1025@item
1026 Do not commit changes to the build system (Makefiles, configure script)
1027 which change behavior, defaults etc, without asking first. The same
1028 applies to compiler warning fixes, trivial looking fixes and to code
1029 maintained by other developers. We usually have a reason for doing things
1030 the way we do. Send your changes as patches to the ffmpeg-devel mailing
1031 list, and if the code maintainers say OK, you may commit. This does not
1032 apply to files you wrote and/or maintain.
1033@item
1034 We refuse source indentation and other cosmetic changes if they are mixed
1035 with functional changes, such commits will be rejected and removed. Every
1036 developer has his own indentation style, you should not change it. Of course
1037 if you (re)write something, you can use your own style, even though we would
1038 prefer if the indentation throughout FFmpeg was consistent (Many projects
1039 force a given indentation style - we do not.). If you really need to make
1040 indentation changes (try to avoid this), separate them strictly from real
1041 changes.
1042
1043 NOTE: If you had to put if()@{ .. @} over a large (> 5 lines) chunk of code,
1044 then either do NOT change the indentation of the inner part within (do not
1045 move it to the right)! or do so in a separate commit
1046@item
1047 Always fill out the commit log message. Describe in a few lines what you
1048 changed and why. You can refer to mailing list postings if you fix a
1049 particular bug. Comments such as "fixed!" or "Changed it." are unacceptable.
1050@item
1051 If you apply a patch by someone else, include the name and email address in
1052 the log message. Since the ffmpeg-cvslog mailing list is publicly
1053 archived you should add some SPAM protection to the email address. Send an
1054 answer to ffmpeg-devel (or wherever you got the patch from) saying that
1055 you applied the patch.
1056@item
1057 When applying patches that have been discussed (at length) on the mailing
1058 list, reference the thread in the log message.
1059@item
1060 Do NOT commit to code actively maintained by others without permission.
1061 Send a patch to ffmpeg-devel instead. If no one answers within a reasonable
1062 timeframe (12h for build failures and security fixes, 3 days small changes,
1063 1 week for big patches) then commit your patch if you think it is OK.
1064 Also note, the maintainer can simply ask for more time to review!
1065@item
1066 Subscribe to the ffmpeg-cvslog mailing list. The diffs of all commits
1067 are sent there and reviewed by all the other developers. Bugs and possible
1068 improvements or general questions regarding commits are discussed there. We
1069 expect you to react if problems with your code are uncovered.
1070@item
1071 Update the documentation if you change behavior or add features. If you are
1072 unsure how best to do this, send a patch to ffmpeg-devel, the documentation
1073 maintainer(s) will review and commit your stuff.
1074@item
1075 Try to keep important discussions and requests (also) on the public
1076 developer mailing list, so that all developers can benefit from them.
1077@item
1078 Never write to unallocated memory, never write over the end of arrays,
1079 always check values read from some untrusted source before using them
1080 as array index or other risky things.
1081@item
1082 Remember to check if you need to bump versions for the specific libav
1083 parts (libavutil, libavcodec, libavformat) you are changing. You need
b98052d5 1084 to change the version integer.
d0e1cd3d
DB
1085 Incrementing the first component means no backward compatibility to
1086 previous versions (e.g. removal of a function from the public API).
1087 Incrementing the second component means backward compatible change
b98052d5
PR
1088 (e.g. addition of a function to the public API or extension of an
1089 existing data structure).
d0e1cd3d
DB
1090 Incrementing the third component means a noteworthy binary compatible
1091 change (e.g. encoder bug fix that matters for the decoder).
1092@item
53407b64 1093 Compiler warnings indicate potential bugs or code with bad style. If a type of
9908c1a8
DB
1094 warning always points to correct and clean code, that warning should
1095 be disabled, not the code changed.
1096 Thus the remaining warnings can either be bugs or correct code.
beaa4a91 1097 If it is a bug, the bug has to be fixed. If it is not, the code should
9908c1a8
DB
1098 be changed to not generate a warning unless that causes a slowdown
1099 or obfuscates the code.
d0e1cd3d
DB
1100@item
1101 If you add a new file, give it a proper license header. Do not copy and
1102 paste it from a random place, use an existing file as template.
1103@end enumerate
1104
1105We think our rules are not too hard. If you have comments, contact us.
1106
1107Note, these rules are mostly borrowed from the MPlayer project.
1108
1109@section Submitting patches
1110
1111First, (@pxref{Coding Rules}) above if you did not yet.
1112
1113When you submit your patch, try to send a unified diff (diff '-up'
1114option). We cannot read other diffs :-)
1115
1116Also please do not submit a patch which contains several unrelated changes.
1117Split it into separate, self-contained pieces. This does not mean splitting
1118file by file. Instead, make the patch as small as possible while still
1119keeping it as a logical unit that contains an individual change, even
1120if it spans multiple files. This makes reviewing your patches much easier
1121for us and greatly increases your chances of getting your patch applied.
1122
1123Run the regression tests before submitting a patch so that you can
1124verify that there are no big problems.
1125
1126Patches should be posted as base64 encoded attachments (or any other
1127encoding which ensures that the patch will not be trashed during
1128transmission) to the ffmpeg-devel mailing list, see
1129@url{http://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel}
1130
1131It also helps quite a bit if you tell us what the patch does (for example
1132'replaces lrint by lrintf'), and why (for example '*BSD isn't C99 compliant
1133and has no lrint()')
1134
1135Also please if you send several patches, send each patch as a separate mail,
1136do not attach several unrelated patches to the same mail.
1137
28ce1839
RP
1138@section New codecs or formats checklist
1139
1140@enumerate
1141@item
1142 Did you use av_cold for codec initialization and close functions?
1143@item
1144 Did you add a long_name under NULL_IF_CONFIG_SMALL to the AVCodec or
1145 AVInputFormat/AVOutputFormat struct?
1146@item
1147 Did you bump the minor version number in @file{avcodec.h} or
1148 @file{avformat.h}?
1149@item
1150 Did you register it in @file{allcodecs.c} or @file{allformats.c}?
1151@item
1152 Did you add the CodecID to @file{avcodec.h}?
1153@item
1154 If it has a fourcc, did you add it to @file{libavformat/riff.c},
1155 even if it is only a decoder?
1156@item
1157 Did you add a rule to compile the appropriate files in the Makefile?
1158 Remember to do this even if you're just adding a format to a file that is
1159 already being compiled by some other rule, like a raw demuxer.
1160@item
1161 Did you add an entry to the table of supported formats or codecs in the
1162 documentation?
1163@item
1164 Did you add an entry in the Changelog?
1165@item
1166 If it depends on a parser or a library, did you add that dependency in
1167 configure?
1168@item
1169 Did you "svn add" the appropriate files before commiting?
1170@end enumerate
1171
d0e1cd3d
DB
1172@section patch submission checklist
1173
1174@enumerate
1175@item
1176 Do the regression tests pass with the patch applied?
1177@item
2cdba8bf
DB
1178 Does @code{make checkheaders} pass with the patch applied?
1179@item
d0e1cd3d
DB
1180 Is the patch a unified diff?
1181@item
1182 Is the patch against latest FFmpeg SVN?
1183@item
1184 Are you subscribed to ffmpeg-dev?
1185 (the list is subscribers only due to spam)
1186@item
1187 Have you checked that the changes are minimal, so that the same cannot be
1188 achieved with a smaller patch and/or simpler final code?
1189@item
1190 If the change is to speed critical code, did you benchmark it?
1191@item
1192 If you did any benchmarks, did you provide them in the mail?
1193@item
1194 Have you checked that the patch does not introduce buffer overflows or
1195 other security issues?
1196@item
63d247ea
DB
1197 Did you test your decoder or demuxer against damaged data? If no, see
1198 tools/trasher and the noise bitstream filter. Your decoder or demuxer
1199 should not crash or end in a (near) infinite loop when fed damaged data.
b885e0db 1200@item
d0e1cd3d
DB
1201 Is the patch created from the root of the source tree, so it can be
1202 applied with @code{patch -p0}?
1203@item
1204 Does the patch not mix functional and cosmetic changes?
1205@item
1206 Did you add tabs or trailing whitespace to the code? Both are forbidden.
1207@item
1208 Is the patch attached to the email you send?
1209@item
1210 Is the mime type of the patch correct? It should be text/x-diff or
1211 text/x-patch or at least text/plain and not application/octet-stream.
1212@item
1213 If the patch fixes a bug, did you provide a verbose analysis of the bug?
1214@item
1215 If the patch fixes a bug, did you provide enough information, including
1216 a sample, so the bug can be reproduced and the fix can be verified?
1217 Note please do not attach samples >100k to mails but rather provide a
0fa5f24c 1218 URL, you can upload to ftp://upload.ffmpeg.org
d0e1cd3d
DB
1219@item
1220 Did you provide a verbose summary about what the patch does change?
1221@item
1222 Did you provide a verbose explanation why it changes things like it does?
1223@item
1224 Did you provide a verbose summary of the user visible advantages and
1225 disadvantages if the patch is applied?
1226@item
1227 Did you provide an example so we can verify the new feature added by the
1228 patch easily?
1229@item
1230 If you added a new file, did you insert a license header? It should be
1231 taken from FFmpeg, not randomly copied and pasted from somewhere else.
1232@item
1233 You should maintain alphabetical order in alphabetically ordered lists as
1234 long as doing so does not break API/ABI compatibility.
1235@item
1236 Lines with similar content should be aligned vertically when doing so
1237 improves readability.
1238@item
1239 Did you provide a suggestion for a clear commit log message?
1240@end enumerate
1241
1242@section Patch review process
1243
1244All patches posted to ffmpeg-devel will be reviewed, unless they contain a
1245clear note that the patch is not for SVN.
1246Reviews and comments will be posted as replies to the patch on the
1247mailing list. The patch submitter then has to take care of every comment,
1248that can be by resubmitting a changed patch or by discussion. Resubmitted
1249patches will themselves be reviewed like any other patch. If at some point
1250a patch passes review with no comments then it is approved, that can for
1251simple and small patches happen immediately while large patches will generally
1252have to be changed and reviewed many times before they are approved.
1253After a patch is approved it will be committed to the repository.
1254
1255We will review all submitted patches, but sometimes we are quite busy so
1256especially for large patches this can take several weeks.
1257
1258When resubmitting patches, please do not make any significant changes
1259not related to the comments received during review. Such patches will
1260be rejected. Instead, submit significant changes or new features as
1261separate patches.
1262
1263@section Regression tests
1264
1265Before submitting a patch (or committing to the repository), you should at least
1266test that you did not break anything.
1267
1268The regression tests build a synthetic video stream and a synthetic
1269audio stream. These are then encoded and decoded with all codecs or
1270formats. The CRC (or MD5) of each generated file is recorded in a
1271result file. A 'diff' is launched to compare the reference results and
1272the result file.
1273
1274The regression tests then go on to test the FFserver code with a
1275limited set of streams. It is important that this step runs correctly
1276as well.
1277
1278Run 'make test' to test all the codecs and formats.
1279
1280Run 'make fulltest' to test all the codecs, formats and FFserver.
1281
1282[Of course, some patches may change the results of the regression tests. In
1283this case, the reference results of the regression tests shall be modified
1284accordingly].
1285
1286@bye