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[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.
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
3d172fb5 248@item PGM, PPM @tab X @tab X
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249@item PGMYUV @tab X @tab X
250 @tab PGM with U and V components in YUV 4:2:0
251@item PNG @tab X @tab X
252 @tab 2/4 bpp not supported yet
253@item PTX @tab @tab X
254 @tab V.Flash PTX format
255@item RAS @tab @tab X
256 @tab Sun Rasterfile
257@item SGI @tab X @tab X
258 @tab SGI RGB image format
259@item Targa @tab @tab X
260 @tab Targa (.TGA) image format
261@item TIFF @tab X @tab X
262 @tab YUV, JPEG and some extension is not supported yet.
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263@end multitable
264
265@code{X} means that encoding (resp. decoding) is supported.
266
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267@code{E} means that support is provided through an external library.
268
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269@section Video Codecs
270
271@multitable @columnfractions .4 .1 .1 .4
b3de4544 272@item Name @tab Encoding @tab Decoding @tab Comments
d66d8b83 273@item 4X Video @tab @tab X
d698c5d3 274 @tab Used in certain computer games.
913c3e2c 275@item American Laser Games MM @tab @tab X
d698c5d3 276 @tab Used in games like Mad Dog McCree.
d66d8b83 277@item AMV @tab @tab X
d698c5d3 278 @tab Used in Chinese MP3 players.
d66d8b83 279@item Apple Animation @tab X @tab X
d698c5d3 280 @tab fourcc: 'rle '
d66d8b83 281@item Apple Graphics @tab @tab X
d698c5d3 282 @tab fourcc: 'smc '
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283@item Apple MJPEG-B @tab @tab X
284@item Apple QuickDraw @tab @tab X
d698c5d3 285 @tab fourcc: qdrw
d66d8b83 286@item Apple Video @tab @tab X
d698c5d3 287 @tab fourcc: rpza
d66d8b83 288@item Asus v1 @tab X @tab X
d698c5d3 289 @tab fourcc: ASV1
d66d8b83 290@item Asus v2 @tab X @tab X
d698c5d3 291 @tab fourcc: ASV2
d66d8b83 292@item ATI VCR1 @tab @tab X
d698c5d3 293 @tab fourcc: VCR1
d66d8b83 294@item ATI VCR2 @tab @tab X
d698c5d3 295 @tab fourcc: VCR2
d66d8b83 296@item Autodesk RLE @tab @tab X
d698c5d3 297 @tab fourcc: AASC
d66d8b83 298@item AVID DNxHD @tab X @tab X
d698c5d3 299 @tab aka SMPTE VC3
bac4c85c 300@item AVS video @tab @tab X
d698c5d3 301 @tab Video encoding used by the Creature Shock game.
d66d8b83 302@item Bethsoft VID @tab @tab X
d698c5d3 303 @tab Used in some games from Bethesda Softworks.
bac4c85c 304@item C93 video @tab @tab X
d698c5d3 305 @tab Codec used in Cyberia game.
d66d8b83 306@item CamStudio @tab @tab X
d698c5d3 307 @tab fourcc: CSCD
bac4c85c 308@item Cin video @tab @tab X
d698c5d3 309 @tab Codec used in Delphine Software games.
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310@item Cinepak @tab @tab X
311@item Cirrus Logic AccuPak @tab @tab X
d698c5d3 312 @tab fourcc: CLJR
d66d8b83 313@item Creative YUV @tab @tab X
d698c5d3 314 @tab fourcc: CYUV
82ced5a9 315@item Dirac @tab E @tab E
360f980b 316 @tab supported through external libdirac/libschroedinger libraries
d66d8b83 317@item Duck TrueMotion v1 @tab @tab X
d698c5d3 318 @tab fourcc: DUCK
d66d8b83 319@item Duck TrueMotion v2 @tab @tab X
d698c5d3 320 @tab fourcc: TM20
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321@item DV @tab X @tab X
322@item DXA Video @tab @tab X
d698c5d3 323 @tab Codec originally used in Feeble Files game.
d66d8b83 324@item Electronic Arts CMV @tab @tab X
d698c5d3 325 @tab Used in NHL 95 game.
cfc78718 326@item Electronic Arts TGV @tab @tab X
42b30357 327@item Electronic Arts TGQ @tab @tab X
d8964f3a 328@item Electronic Arts TQI @tab @tab X
d66d8b83 329@item FFmpeg Video 1 @tab X @tab X
d698c5d3 330 @tab experimental lossless codec (fourcc: FFV1)
d66d8b83 331@item Flash Screen Video @tab X @tab X
d698c5d3 332 @tab fourcc: FSV1
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333@item FLIC video @tab @tab X
334@item FLV @tab X @tab X
d698c5d3 335 @tab Sorenson H.263 used in Flash
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336@item Fraps FPS1 @tab @tab X
337@item H.261 @tab X @tab X
338@item H.263(+) @tab X @tab X
d698c5d3 339 @tab also known as RealVideo 1.0
82ced5a9 340@item H.264 @tab E @tab X
360f980b 341 @tab encoding supported through external library libx264
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342@item HuffYUV @tab X @tab X
343@item IBM Ultimotion @tab @tab X
d698c5d3 344 @tab fourcc: ULTI
bac4c85c 345@item id Cinematic video @tab @tab X
d698c5d3 346 @tab Used in Quake II.
d66d8b83 347@item id RoQ @tab X @tab X
d698c5d3 348 @tab Used in Quake III, Jedi Knight 2, other computer games.
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349@item Intel Indeo 3 @tab @tab X
350@item Interplay Video @tab @tab X
d698c5d3 351 @tab Used in Interplay .MVE files.
d66d8b83 352@item JPEG-LS @tab X @tab X
d698c5d3 353 @tab fourcc: MJLS, lossless and near-lossless is supported.
d66d8b83 354@item KMVC @tab @tab X
d698c5d3 355 @tab Codec used in Worms games.
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356@item LOCO @tab @tab X
357@item lossless MJPEG @tab X @tab X
358@item Microsoft RLE @tab @tab X
359@item Microsoft Video-1 @tab @tab X
360@item Mimic @tab @tab X
d698c5d3 361 @tab Used in MSN Messenger Webcam streams.
d66d8b83 362@item Miro VideoXL @tab @tab X
d698c5d3 363 @tab fourcc: VIXL
d66d8b83 364@item MJPEG @tab X @tab X
822cc8f7 365@item Motion Pixels Video @tab @tab X
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366@item MPEG-1 @tab X @tab X
367@item MPEG-2 @tab X @tab X
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368@item MPEG-4 @tab X @tab X
369@item MSMPEG4 V1 @tab X @tab X
370@item MSMPEG4 V2 @tab X @tab X
371@item MSMPEG4 V3 @tab X @tab X
d66d8b83 372@item MSZH @tab @tab X
d698c5d3 373 @tab Part of LCL
d66d8b83 374@item On2 VP3 @tab @tab X
d698c5d3 375 @tab still experimental
d66d8b83 376@item On2 VP5 @tab @tab X
d698c5d3 377 @tab fourcc: VP50
d66d8b83 378@item On2 VP6 @tab @tab X
d698c5d3 379 @tab fourcc: VP60,VP61,VP62
d66d8b83 380@item planar RGB @tab @tab X
d698c5d3 381 @tab fourcc: 8BPS
d66d8b83 382@item QPEG @tab @tab X
d698c5d3 383 @tab fourccs: QPEG, Q1.0, Q1.1
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384@item RealVideo 1.0 @tab X @tab X
385@item RealVideo 2.0 @tab X @tab X
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386@item RealVideo 3.0 @tab @tab X
387 @tab still far from ideal
11c0f9ec 388@item RealVideo 4.0 @tab @tab X
d66d8b83 389@item Renderware TXD @tab @tab X
d698c5d3 390 @tab Texture dictionaries used by the Renderware Engine.
d66d8b83 391@item RTjpeg @tab @tab X
d698c5d3 392 @tab Video encoding used in NuppelVideo files.
bac4c85c 393@item Smacker video @tab @tab X
d698c5d3 394 @tab Video encoding used in Smacker.
d66d8b83 395@item Snow @tab X @tab X
d698c5d3 396 @tab experimental wavelet codec (fourcc: SNOW)
831ec935 397@item Sony PlayStation MDEC @tab @tab X
d66d8b83 398@item Sorenson Video 1 @tab X @tab X
d698c5d3 399 @tab fourcc: SVQ1
d66d8b83 400@item Sorenson Video 3 @tab @tab X
d698c5d3 401 @tab fourcc: SVQ3
d66d8b83 402@item Sunplus MJPEG @tab @tab X
d698c5d3 403 @tab fourcc: SP5X
d66d8b83 404@item TechSmith Camtasia @tab @tab X
d698c5d3 405 @tab fourcc: TSCC
82ced5a9 406@item Theora @tab E @tab X
360f980b 407 @tab encoding supported through external library libtheora
d66d8b83 408@item THP @tab @tab X
d698c5d3 409 @tab Used on the Nintendo GameCube.
bac4c85c 410@item Tiertex Seq video @tab @tab X
d698c5d3 411 @tab Codec used in DOS CD-ROM FlashBack game.
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412@item VC-1 @tab @tab X
413@item VMD Video @tab @tab X
d698c5d3 414 @tab Used in Sierra VMD files.
d66d8b83 415@item VMware Video @tab @tab X
d698c5d3 416 @tab Codec used in videos captured by VMware.
d0e1cd3d 417@item Westwood VQA @tab @tab X
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418@item Winnov WNV1 @tab @tab X
419@item WMV7 @tab X @tab X
420@item WMV8 @tab X @tab X
421@item WMV9 @tab @tab X
d698c5d3 422 @tab not completely working
d66d8b83 423@item Xan/WC3 @tab @tab X
d698c5d3 424 @tab Used in Wing Commander III .MVE files.
39271be4 425@item YAMAHA SMAF @tab X @tab X
d66d8b83 426@item ZLIB @tab X @tab X
d698c5d3 427 @tab part of LCL, encoder experimental
d66d8b83 428@item ZMBV @tab X @tab X
d698c5d3 429 @tab Encoder works only in PAL8.
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430@end multitable
431
432@code{X} means that encoding (resp. decoding) is supported.
433
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434@code{E} means that support is provided through an external library.
435
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436@section Audio Codecs
437
485ec4f1 438@multitable @columnfractions .4 .1 .1 .4
b3de4544 439@item Name @tab Encoding @tab Decoding @tab Comments
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440@item 4X IMA ADPCM @tab @tab X
441@item 8SVX audio @tab @tab X
82ced5a9 442@item AAC @tab E @tab X
360f980b 443 @tab encoding supported through external library libfaac
16d81b27 444@item AC-3 @tab IX @tab IX
82ced5a9 445@item AMR-NB @tab E @tab E
360f980b 446 @tab supported through external library libamrnb
82ced5a9 447@item AMR-WB @tab E @tab E
360f980b 448 @tab supported through external library libamrwb
16d81b27 449@item AMV IMA ADPCM @tab @tab X
d698c5d3 450 @tab Used in AMV files
833e90dd 451@item Apple lossless audio @tab X @tab X
d698c5d3 452 @tab QuickTime fourcc 'alac'
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453@item Apple MACE 3 @tab @tab X
454@item Apple MACE 6 @tab @tab X
455@item ATRAC 3 @tab @tab X
456@item CD-ROM XA ADPCM @tab @tab X
bac4c85c 457@item Cin audio @tab @tab X
d698c5d3 458 @tab Codec used in Delphine Software International games.
16d81b27 459@item Creative ADPCM @tab @tab X
d698c5d3 460 @tab 16 -> 4, 8 -> 4, 8 -> 3, 8 -> 2
16d81b27 461@item CRI ADX ADPCM @tab X @tab X
d698c5d3 462 @tab Used in Sega Dreamcast games.
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463@item DSP Group TrueSpeech @tab @tab X
464@item DTS Coherent Audio @tab @tab X
465@item Duck DK3 IMA ADPCM @tab @tab X
d698c5d3 466 @tab Used in some Sega Saturn console games.
16d81b27 467@item Duck DK4 IMA ADPCM @tab @tab X
d698c5d3 468 @tab Used in some Sega Saturn console games.
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469@item DV audio @tab @tab X
470@item Electronic Arts ADPCM @tab @tab X
d698c5d3 471 @tab Used in various EA titles.
44723c84 472@item Enhanced AC-3 @tab @tab X
9a584db4 473@item FLAC lossless audio @tab IX @tab X
16d81b27 474@item G.726 ADPCM @tab X @tab X
82ced5a9 475@item GSM @tab E @tab E
3f33271a 476 @tab supported through external library libgsm
82ced5a9 477@item GSM_MS @tab E @tab E
3f33271a 478 @tab supported through external library libgsm
16d81b27 479@item id RoQ DPCM @tab X @tab X
d698c5d3 480 @tab Used in Quake III, Jedi Knight 2, other computer games.
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481@item Intel Music Coder @tab @tab X
482@item Interplay MVE DPCM @tab @tab X
d698c5d3 483 @tab Used in various Interplay computer games.
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484@item ISS IMA ADPCM @tab @tab X
485 @tab Used in FunCom games.
16d81b27 486@item MAXIS EA ADPCM @tab @tab X
d698c5d3 487 @tab Used in Sim City 3000.
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488@item Microsoft ADPCM @tab X @tab X
489@item MLP/TrueHD @tab @tab X
d698c5d3 490 @tab Used in DVD-Audio and Blu-Ray discs.
16d81b27 491@item Monkey's Audio @tab @tab X
d698c5d3 492 @tab Only versions 3.97-3.99 are supported.
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493@item MPEG audio layer 3 @tab E @tab IX
494 @tab encoding supported through external library LAME
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495@item MPEG audio layer 2 @tab IX @tab IX
496@item MS IMA ADPCM @tab X @tab X
497@item Musepack @tab @tab X
d698c5d3 498 @tab SV7 and SV8 are supported.
755ba886 499@item Nellymoser ASAO @tab X @tab X
73b458e3 500@item QCELP / PureVoice @tab @tab X
16d81b27 501@item Qdesign QDM2 @tab @tab X
d698c5d3 502 @tab There are still some distortions.
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503@item QT IMA ADPCM @tab X @tab X
504@item RA144 @tab @tab X
d698c5d3 505 @tab Real 14400 bit/s codec
16d81b27 506@item RA288 @tab @tab X
d698c5d3 507 @tab Real 28800 bit/s codec
575a5bf2 508@item RADnet @tab IX @tab IX
a692130f 509 @tab Real low bitrate AC-3 codec
16d81b27 510@item Real COOK @tab @tab X
d698c5d3 511 @tab All versions except 5.1 are supported.
bac4c85c 512@item Shorten @tab @tab X
16d81b27 513@item Sierra Online DPCM @tab @tab X
d698c5d3 514 @tab Used in Sierra Online game audio files.
bac4c85c 515@item Smacker audio @tab @tab X
16d81b27 516@item SMJPEG IMA ADPCM @tab @tab X
d698c5d3 517 @tab Used in certain Loki game ports.
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518@item Sonic @tab X @tab X
519 @tab experimental codec
520@item Sonic lossless @tab X @tab X
521 @tab experimental codec
82ced5a9 522@item Speex @tab @tab E
360f980b 523 @tab supported through external library libspeex
16d81b27 524@item THP ADPCM @tab @tab X
d698c5d3 525 @tab Used on the Nintendo GameCube.
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526@item True Audio (TTA) @tab @tab X
527@item Vorbis @tab X @tab X
bac4c85c 528@item WavPack @tab @tab X
16d81b27 529@item Westwood Studios IMA ADPCM @tab @tab X
d698c5d3 530 @tab Used in Westwood Studios games like Command and Conquer.
bac4c85c 531@item WMA v1/v2 @tab X @tab X
16d81b27 532@item Xan DPCM @tab @tab X
d698c5d3 533 @tab Used in Origin's Wing Commander IV AVI files.
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534@end multitable
535
536@code{X} means that encoding (resp. decoding) is supported.
537
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538@code{E} means that support is provided through an external library.
539
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540@code{I} means that an integer-only version is available, too (ensures high
541performance on systems without hardware floating point support).
542
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543@section Subtitle Formats
544
485ec4f1 545@multitable @columnfractions .4 .1 .1 .1 .1 .1
9afc2917 546@item Name @tab Muxing @tab Demuxing @tab Encoding @tab Decoding
913c3e2c 547@item SSA/ASS @tab X @tab X
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548@item DVB @tab X @tab X @tab X @tab X
549@item DVD @tab X @tab X @tab X @tab X
550@item XSUB @tab @tab @tab @tab X
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551@end multitable
552
553@code{X} means that the feature is supported.
554
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555@section Network Protocols
556
557@multitable @columnfractions .4 .1 .1 .1 .1 .1
558@item Name @tab Support
559@item file @tab X
560@item Gopher @tab X
561@item HTTP @tab X
562@item pipe @tab X
563@item RTP @tab X
564@item TCP @tab X
565@item UDP @tab X
566@end multitable
567
568@code{X} means that the protocol is supported.
569
570
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571@chapter Platform Specific information
572
573@section BSD
574
575BSD make will not build FFmpeg, you need to install and use GNU Make
576(@file{gmake}).
577
578@section Windows
579
46a845d0 580To get help and instructions for building FFmpeg under Windows, check out
d0e1cd3d 581the FFmpeg Windows Help Forum at
ab5ce4ae 582@url{http://ffmpeg.arrozcru.org/}.
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583
584@subsection Native Windows compilation
585
c1989552 586FFmpeg can be built to run natively on Windows using the MinGW tools. Install
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587the latest versions of MSYS and MinGW from @url{http://www.mingw.org/}.
588You can find detailed installation
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589instructions in the download section and the FAQ.
590
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591FFmpeg does not build out-of-the-box with the packages the automated MinGW
592installer provides. It also requires coreutils to be installed and many other
593packages updated to the latest version. The minimum version for some packages
594are listed below:
595
596@itemize
597@item bash 3.1
598@item msys-make 3.81-2 (note: not mingw32-make)
2014b51c 599@item w32api 3.13
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600@item mingw-runtime 3.15
601@end itemize
602
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603You will also need to pass @code{-fno-common} to the compiler to work around
604a GCC bug (see @url{http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37216}).
605
c1989552 606Within the MSYS shell, configure and make with:
d0e1cd3d 607
c1989552 608@example
0f898714 609./configure --enable-memalign-hack --extra-cflags=-fno-common
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610make
611make install
612@end example
d0e1cd3d 613
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614This will install @file{ffmpeg.exe} along with many other development files
615to @file{/usr/local}. You may specify another install path using the
616@code{--prefix} option in @file{configure}.
d0e1cd3d 617
c1989552 618Notes:
d0e1cd3d 619
c1989552 620@itemize
d0e1cd3d 621
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622@item In order to compile vhooks, you must have a POSIX-compliant libdl in
623your MinGW system. Get dlfcn-win32 from
624@url{http://code.google.com/p/dlfcn-win32}.
d0e1cd3d 625
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626@item In order to compile FFplay, you must have the MinGW development library
627of SDL. Get it from @url{http://www.libsdl.org}.
628Edit the @file{bin/sdl-config} script so that it points to the correct prefix
629where SDL was installed. Verify that @file{sdl-config} can be launched from
630the MSYS command line.
d0e1cd3d 631
d0e1cd3d 632@item By using @code{./configure --enable-shared} when configuring FFmpeg,
c1989552 633you can build libavutil, libavcodec and libavformat as DLLs.
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634
635@end itemize
636
c1989552 637@subsection Microsoft Visual C++ compatibility
d0e1cd3d 638
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639As stated in the FAQ, FFmpeg will not compile under MSVC++. However, if you
640want to use the libav* libraries in your own applications, you can still
641compile those applications using MSVC++. But the libav* libraries you link
642to @emph{must} be built with MinGW. However, you will not be able to debug
643inside the libav* libraries, since MSVC++ does not recognize the debug
644symbols generated by GCC.
645We strongly recommend you to move over from MSVC++ to MinGW tools.
d0e1cd3d 646
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647This description of how to use the FFmpeg libraries with MSVC++ is based on
648Microsoft Visual C++ 2005 Express Edition. If you have a different version,
649you might have to modify the procedures slightly.
d0e1cd3d 650
c1989552 651@subsubsection Using static libraries
d0e1cd3d 652
c1989552 653Assuming you have just built and installed FFmpeg in @file{/usr/local}.
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654
655@enumerate
656
657@item Create a new console application ("File / New / Project") and then
658select "Win32 Console Application". On the appropriate page of the
659Application Wizard, uncheck the "Precompiled headers" option.
660
661@item Write the source code for your application, or, for testing, just
662copy the code from an existing sample application into the source file
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663that MSVC++ has already created for you. For example, you can copy
664@file{output_example.c} from the FFmpeg distribution.
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665
666@item Open the "Project / Properties" dialog box. In the "Configuration"
667combo box, select "All Configurations" so that the changes you make will
668affect both debug and release builds. In the tree view on the left hand
669side, select "C/C++ / General", then edit the "Additional Include
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670Directories" setting to contain the path where the FFmpeg includes were
671installed (i.e. @file{c:\msys\1.0\local\include}).
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672Do not add MinGW's include directory here, or the include files will
673conflict with MSVC's.
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674
675@item Still in the "Project / Properties" dialog box, select
676"Linker / General" from the tree view and edit the
677"Additional Library Directories" setting to contain the @file{lib}
678directory where FFmpeg was installed (i.e. @file{c:\msys\1.0\local\lib}),
679the directory where MinGW libs are installed (i.e. @file{c:\mingw\lib}),
680and the directory where MinGW's GCC libs are installed
681(i.e. @file{C:\mingw\lib\gcc\mingw32\4.2.1-sjlj}). Then select
682"Linker / Input" from the tree view, and add the files @file{libavformat.a},
683@file{libavcodec.a}, @file{libavutil.a}, @file{libmingwex.a},
684@file{libgcc.a}, and any other libraries you used (i.e. @file{libz.a})
685to the end of "Additional Dependencies".
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686
687@item Now, select "C/C++ / Code Generation" from the tree view. Select
688"Debug" in the "Configuration" combo box. Make sure that "Runtime
689Library" is set to "Multi-threaded Debug DLL". Then, select "Release" in
690the "Configuration" combo box and make sure that "Runtime Library" is
691set to "Multi-threaded DLL".
692
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693@item Click "OK" to close the "Project / Properties" dialog box.
694
695@item MSVC++ lacks some C99 header files that are fundamental for FFmpeg.
696Get msinttypes from @url{http://code.google.com/p/msinttypes/downloads/list}
697and install it in MSVC++'s include directory
698(i.e. @file{C:\Program Files\Microsoft Visual Studio 8\VC\include}).
699
700@item MSVC++ also does not understand the @code{inline} keyword used by
701FFmpeg, so you must add this line before @code{#include}ing libav*:
702@example
703#define inline _inline
704@end example
705
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706@item Build your application, everything should work.
707
708@end enumerate
709
710@subsubsection Using shared libraries
711
712This is how to create DLL and LIB files that are compatible with MSVC++:
713
714@enumerate
715
716@item Add a call to @file{vcvars32.bat} (which sets up the environment
717variables for the Visual C++ tools) as the first line of @file{msys.bat}.
718The standard location for @file{vcvars32.bat} is
719@file{C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat},
720and the standard location for @file{msys.bat} is @file{C:\msys\1.0\msys.bat}.
721If this corresponds to your setup, add the following line as the first line
722of @file{msys.bat}:
723
724@example
725call "C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat"
726@end example
727
728Alternatively, you may start the @file{Visual Studio 2005 Command Prompt},
729and run @file{c:\msys\1.0\msys.bat} from there.
730
731@item Within the MSYS shell, run @code{lib.exe}. If you get a help message
732from @file{Microsoft (R) Library Manager}, this means your environment
733variables are set up correctly, the @file{Microsoft (R) Library Manager}
734is on the path and will be used by FFmpeg to create
735MSVC++-compatible import libraries.
736
737@item Build FFmpeg with
738
739@example
740./configure --enable-shared --enable-memalign-hack
741make
742make install
743@end example
744
745Your install path (@file{/usr/local/} by default) should now have the
746necessary DLL and LIB files under the @file{bin} directory.
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747
748@end enumerate
749
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750To use those files with MSVC++, do the same as you would do with
751the static libraries, as described above. But in Step 4,
752you should only need to add the directory where the LIB files are installed
753(i.e. @file{c:\msys\usr\local\bin}). This is not a typo, the LIB files are
754installed in the @file{bin} directory. And instead of adding @file{libxx.a}
755files, you should add @file{avcodec.lib}, @file{avformat.lib}, and
756@file{avutil.lib}. There should be no need for @file{libmingwex.a},
757@file{libgcc.a}, and @file{wsock32.lib}, nor any other external library
758statically linked into the DLLs. The @file{bin} directory contains a bunch
759of DLL files, but the ones that are actually used to run your application
760are the ones with a major version number in their filenames
761(i.e. @file{avcodec-51.dll}).
762
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763@subsection Cross compilation for Windows with Linux
764
765You must use the MinGW cross compilation tools available at
766@url{http://www.mingw.org/}.
767
768Then configure FFmpeg with the following options:
769@example
770./configure --target-os=mingw32 --cross-prefix=i386-mingw32msvc-
771@end example
772(you can change the cross-prefix according to the prefix chosen for the
773MinGW tools).
774
775Then you can easily test FFmpeg with Wine
776(@url{http://www.winehq.com/}).
777
778@subsection Compilation under Cygwin
779
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780The main issue with the 1.5.x Cygwin versions is that newlib, its C library,
781does not contain llrint(). You need to upgrade to the unstable 1.7.x versions,
782or leverage the implementation in MinGW (as explained below).
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783
784Just install your Cygwin with all the "Base" packages, plus the
785following "Devel" ones:
786@example
f496ab12 787binutils, gcc-core, make, subversion, mingw-runtime, diffutils
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788@end example
789
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790The experimental gcc4 package is still buggy, hence please
791use the official gcc 3.4.4 or a 4.2.x compiled from source by yourself.
792
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793Install the current binutils-20080624-2 as they work fine (the old
794binutils-20060709-1 proved buggy on shared builds).
d0e1cd3d 795
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796Then create a small library that just contains llrint():
797
798@example
799ar x /usr/lib/mingw/libmingwex.a llrint.o
800ar cq /usr/local/lib/libllrint.a llrint.o
801@end example
802
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803Then run
804
805@example
29c3d42b 806./configure --enable-static --disable-shared --extra-ldflags='-L /usr/local/lib' --extra-libs='-l llrint'
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807@end example
808
809to make a static build or
810
811@example
29c3d42b 812./configure --enable-shared --disable-static --extra-ldflags='-L /usr/local/lib' --extra-libs='-l llrint'
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813@end example
814
815to build shared libraries.
816
817If you want to build FFmpeg with additional libraries, download Cygwin
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818"Devel" packages for Ogg and Vorbis from any Cygwin packages repository:
819@example
820libogg-devel, libvorbis-devel
821@end example
822
823These library packages are only available from Cygwin Ports
be8497b0 824(@url{http://sourceware.org/cygwinports/}) :
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825
826@example
827yasm, libSDL-devel, libdirac-devel, libfaac-devel, libfaad-devel, libgsm-devel,
828libmp3lame-devel, libschroedinger1.0-devel, speex-devel, libtheora-devel,
829libxvidcore-devel
830@end example
831
832The recommendation for libnut and x264 is to build them from source by
833yourself, as they evolve too quickly for Cygwin Ports to be up to date.
d0e1cd3d 834
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835Cygwin 1.7.x has IPv6 support. You can add IPv6 to Cygwin 1.5.x by means
836of the @code{libgetaddrinfo-devel} package, available at Cygwin Ports.
837
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838@subsection Crosscompilation for Windows under Cygwin
839
840With Cygwin you can create Windows binaries that do not need the cygwin1.dll.
841
842Just install your Cygwin as explained before, plus these additional
843"Devel" packages:
844@example
845gcc-mingw-core, mingw-runtime, mingw-zlib
846@end example
847
848and add some special flags to your configure invocation.
849
850For a static build run
851@example
852./configure --target-os=mingw32 --enable-memalign-hack --enable-static --disable-shared --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
853@end example
854
855and for a build with shared libraries
856@example
857./configure --target-os=mingw32 --enable-memalign-hack --enable-shared --disable-static --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
858@end example
859
860@section BeOS
861
5f757b85 862BeOS support is broken in mysterious ways.
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864@section OS/2
865
866For information about compiling FFmpeg on OS/2 see
867@url{http://www.edm2.com/index.php/FFmpeg}.
868
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869@chapter Developers Guide
870
871@section API
872@itemize @bullet
873@item libavcodec is the library containing the codecs (both encoding and
874decoding). Look at @file{libavcodec/apiexample.c} to see how to use it.
875
876@item libavformat is the library containing the file format handling (mux and
877demux code for several formats). Look at @file{ffplay.c} to use it in a
878player. See @file{output_example.c} to use it to generate audio or video
879streams.
880
881@end itemize
882
883@section Integrating libavcodec or libavformat in your program
884
885You can integrate all the source code of the libraries to link them
886statically to avoid any version problem. All you need is to provide a
887'config.mak' and a 'config.h' in the parent directory. See the defines
888generated by ./configure to understand what is needed.
889
890You can use libavcodec or libavformat in your commercial program, but
891@emph{any patch you make must be published}. The best way to proceed is
892to send your patches to the FFmpeg mailing list.
893
894@node Coding Rules
895@section Coding Rules
896
897FFmpeg is programmed in the ISO C90 language with a few additional
898features from ISO C99, namely:
899@itemize @bullet
900@item
901the @samp{inline} keyword;
902@item
903@samp{//} comments;
904@item
905designated struct initializers (@samp{struct s x = @{ .i = 17 @};})
906@item
907compound literals (@samp{x = (struct s) @{ 17, 23 @};})
908@end itemize
909
910These features are supported by all compilers we care about, so we will not
911accept patches to remove their use unless they absolutely do not impair
912clarity and performance.
913
914All code must compile with GCC 2.95 and GCC 3.3. Currently, FFmpeg also
915compiles with several other compilers, such as the Compaq ccc compiler
916or Sun Studio 9, and we would like to keep it that way unless it would
917be exceedingly involved. To ensure compatibility, please do not use any
918additional C99 features or GCC extensions. Especially watch out for:
919@itemize @bullet
920@item
921mixing statements and declarations;
922@item
923@samp{long long} (use @samp{int64_t} instead);
924@item
925@samp{__attribute__} not protected by @samp{#ifdef __GNUC__} or similar;
926@item
927GCC statement expressions (@samp{(x = (@{ int y = 4; y; @})}).
928@end itemize
929
930Indent size is 4.
931The presentation is the one specified by 'indent -i4 -kr -nut'.
932The TAB character is forbidden outside of Makefiles as is any
933form of trailing whitespace. Commits containing either will be
934rejected by the Subversion repository.
935
936The main priority in FFmpeg is simplicity and small code size in order to
937minimize the bug count.
938
939Comments: Use the JavaDoc/Doxygen
940format (see examples below) so that code documentation
941can be generated automatically. All nontrivial functions should have a comment
942above them explaining what the function does, even if it is just one sentence.
943All structures and their member variables should be documented, too.
944@example
945/**
946 * @@file mpeg.c
947 * MPEG codec.
948 * @@author ...
949 */
950
951/**
952 * Summary sentence.
953 * more text ...
954 * ...
955 */
956typedef struct Foobar@{
957 int var1; /**< var1 description */
958 int var2; ///< var2 description
959 /** var3 description */
960 int var3;
961@} Foobar;
962
963/**
964 * Summary sentence.
965 * more text ...
966 * ...
967 * @@param my_parameter description of my_parameter
968 * @@return return value description
969 */
970int myfunc(int my_parameter)
971...
972@end example
973
974fprintf and printf are forbidden in libavformat and libavcodec,
975please use av_log() instead.
976
977Casts should be used only when necessary. Unneeded parentheses
978should also be avoided if they don't make the code easier to understand.
979
980@section Development Policy
981
982@enumerate
983@item
984 Contributions should be licensed under the LGPL 2.1, including an
985 "or any later version" clause, or the MIT license. GPL 2 including
986 an "or any later version" clause is also acceptable, but LGPL is
987 preferred.
988@item
989 You must not commit code which breaks FFmpeg! (Meaning unfinished but
990 enabled code which breaks compilation or compiles but does not work or
991 breaks the regression tests)
992 You can commit unfinished stuff (for testing etc), but it must be disabled
993 (#ifdef etc) by default so it does not interfere with other developers'
994 work.
995@item
996 You do not have to over-test things. If it works for you, and you think it
997 should work for others, then commit. If your code has problems
998 (portability, triggers compiler bugs, unusual environment etc) they will be
999 reported and eventually fixed.
1000@item
1001 Do not commit unrelated changes together, split them into self-contained
1002 pieces. Also do not forget that if part B depends on part A, but A does not
1003 depend on B, then A can and should be committed first and separate from B.
1004 Keeping changes well split into self-contained parts makes reviewing and
1005 understanding them on the commit log mailing list easier. This also helps
1006 in case of debugging later on.
1007 Also if you have doubts about splitting or not splitting, do not hesitate to
1008 ask/discuss it on the developer mailing list.
1009@item
1010 Do not change behavior of the program (renaming options etc) without
1011 first discussing it on the ffmpeg-devel mailing list. Do not remove
1012 functionality from the code. Just improve!
1013
1014 Note: Redundant code can be removed.
1015@item
1016 Do not commit changes to the build system (Makefiles, configure script)
1017 which change behavior, defaults etc, without asking first. The same
1018 applies to compiler warning fixes, trivial looking fixes and to code
1019 maintained by other developers. We usually have a reason for doing things
1020 the way we do. Send your changes as patches to the ffmpeg-devel mailing
1021 list, and if the code maintainers say OK, you may commit. This does not
1022 apply to files you wrote and/or maintain.
1023@item
1024 We refuse source indentation and other cosmetic changes if they are mixed
1025 with functional changes, such commits will be rejected and removed. Every
1026 developer has his own indentation style, you should not change it. Of course
1027 if you (re)write something, you can use your own style, even though we would
1028 prefer if the indentation throughout FFmpeg was consistent (Many projects
1029 force a given indentation style - we do not.). If you really need to make
1030 indentation changes (try to avoid this), separate them strictly from real
1031 changes.
1032
1033 NOTE: If you had to put if()@{ .. @} over a large (> 5 lines) chunk of code,
1034 then either do NOT change the indentation of the inner part within (do not
1035 move it to the right)! or do so in a separate commit
1036@item
1037 Always fill out the commit log message. Describe in a few lines what you
1038 changed and why. You can refer to mailing list postings if you fix a
1039 particular bug. Comments such as "fixed!" or "Changed it." are unacceptable.
1040@item
1041 If you apply a patch by someone else, include the name and email address in
1042 the log message. Since the ffmpeg-cvslog mailing list is publicly
1043 archived you should add some SPAM protection to the email address. Send an
1044 answer to ffmpeg-devel (or wherever you got the patch from) saying that
1045 you applied the patch.
1046@item
1047 When applying patches that have been discussed (at length) on the mailing
1048 list, reference the thread in the log message.
1049@item
1050 Do NOT commit to code actively maintained by others without permission.
1051 Send a patch to ffmpeg-devel instead. If no one answers within a reasonable
1052 timeframe (12h for build failures and security fixes, 3 days small changes,
1053 1 week for big patches) then commit your patch if you think it is OK.
1054 Also note, the maintainer can simply ask for more time to review!
1055@item
1056 Subscribe to the ffmpeg-cvslog mailing list. The diffs of all commits
1057 are sent there and reviewed by all the other developers. Bugs and possible
1058 improvements or general questions regarding commits are discussed there. We
1059 expect you to react if problems with your code are uncovered.
1060@item
1061 Update the documentation if you change behavior or add features. If you are
1062 unsure how best to do this, send a patch to ffmpeg-devel, the documentation
1063 maintainer(s) will review and commit your stuff.
1064@item
1065 Try to keep important discussions and requests (also) on the public
1066 developer mailing list, so that all developers can benefit from them.
1067@item
1068 Never write to unallocated memory, never write over the end of arrays,
1069 always check values read from some untrusted source before using them
1070 as array index or other risky things.
1071@item
1072 Remember to check if you need to bump versions for the specific libav
1073 parts (libavutil, libavcodec, libavformat) you are changing. You need
b98052d5 1074 to change the version integer.
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1075 Incrementing the first component means no backward compatibility to
1076 previous versions (e.g. removal of a function from the public API).
1077 Incrementing the second component means backward compatible change
b98052d5
PR
1078 (e.g. addition of a function to the public API or extension of an
1079 existing data structure).
d0e1cd3d
DB
1080 Incrementing the third component means a noteworthy binary compatible
1081 change (e.g. encoder bug fix that matters for the decoder).
1082@item
53407b64 1083 Compiler warnings indicate potential bugs or code with bad style. If a type of
9908c1a8
DB
1084 warning always points to correct and clean code, that warning should
1085 be disabled, not the code changed.
1086 Thus the remaining warnings can either be bugs or correct code.
beaa4a91 1087 If it is a bug, the bug has to be fixed. If it is not, the code should
9908c1a8
DB
1088 be changed to not generate a warning unless that causes a slowdown
1089 or obfuscates the code.
d0e1cd3d
DB
1090@item
1091 If you add a new file, give it a proper license header. Do not copy and
1092 paste it from a random place, use an existing file as template.
1093@end enumerate
1094
1095We think our rules are not too hard. If you have comments, contact us.
1096
1097Note, these rules are mostly borrowed from the MPlayer project.
1098
1099@section Submitting patches
1100
1101First, (@pxref{Coding Rules}) above if you did not yet.
1102
1103When you submit your patch, try to send a unified diff (diff '-up'
1104option). We cannot read other diffs :-)
1105
1106Also please do not submit a patch which contains several unrelated changes.
1107Split it into separate, self-contained pieces. This does not mean splitting
1108file by file. Instead, make the patch as small as possible while still
1109keeping it as a logical unit that contains an individual change, even
1110if it spans multiple files. This makes reviewing your patches much easier
1111for us and greatly increases your chances of getting your patch applied.
1112
1113Run the regression tests before submitting a patch so that you can
1114verify that there are no big problems.
1115
1116Patches should be posted as base64 encoded attachments (or any other
1117encoding which ensures that the patch will not be trashed during
1118transmission) to the ffmpeg-devel mailing list, see
1119@url{http://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel}
1120
1121It also helps quite a bit if you tell us what the patch does (for example
1122'replaces lrint by lrintf'), and why (for example '*BSD isn't C99 compliant
1123and has no lrint()')
1124
1125Also please if you send several patches, send each patch as a separate mail,
1126do not attach several unrelated patches to the same mail.
1127
28ce1839
RP
1128@section New codecs or formats checklist
1129
1130@enumerate
1131@item
1132 Did you use av_cold for codec initialization and close functions?
1133@item
1134 Did you add a long_name under NULL_IF_CONFIG_SMALL to the AVCodec or
1135 AVInputFormat/AVOutputFormat struct?
1136@item
1137 Did you bump the minor version number in @file{avcodec.h} or
1138 @file{avformat.h}?
1139@item
1140 Did you register it in @file{allcodecs.c} or @file{allformats.c}?
1141@item
1142 Did you add the CodecID to @file{avcodec.h}?
1143@item
1144 If it has a fourcc, did you add it to @file{libavformat/riff.c},
1145 even if it is only a decoder?
1146@item
1147 Did you add a rule to compile the appropriate files in the Makefile?
1148 Remember to do this even if you're just adding a format to a file that is
1149 already being compiled by some other rule, like a raw demuxer.
1150@item
1151 Did you add an entry to the table of supported formats or codecs in the
1152 documentation?
1153@item
1154 Did you add an entry in the Changelog?
1155@item
1156 If it depends on a parser or a library, did you add that dependency in
1157 configure?
1158@item
1159 Did you "svn add" the appropriate files before commiting?
1160@end enumerate
1161
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1162@section patch submission checklist
1163
1164@enumerate
1165@item
1166 Do the regression tests pass with the patch applied?
1167@item
2cdba8bf
DB
1168 Does @code{make checkheaders} pass with the patch applied?
1169@item
d0e1cd3d
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1170 Is the patch a unified diff?
1171@item
1172 Is the patch against latest FFmpeg SVN?
1173@item
1174 Are you subscribed to ffmpeg-dev?
1175 (the list is subscribers only due to spam)
1176@item
1177 Have you checked that the changes are minimal, so that the same cannot be
1178 achieved with a smaller patch and/or simpler final code?
1179@item
1180 If the change is to speed critical code, did you benchmark it?
1181@item
1182 If you did any benchmarks, did you provide them in the mail?
1183@item
1184 Have you checked that the patch does not introduce buffer overflows or
1185 other security issues?
1186@item
63d247ea
DB
1187 Did you test your decoder or demuxer against damaged data? If no, see
1188 tools/trasher and the noise bitstream filter. Your decoder or demuxer
1189 should not crash or end in a (near) infinite loop when fed damaged data.
b885e0db 1190@item
d0e1cd3d
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1191 Is the patch created from the root of the source tree, so it can be
1192 applied with @code{patch -p0}?
1193@item
1194 Does the patch not mix functional and cosmetic changes?
1195@item
1196 Did you add tabs or trailing whitespace to the code? Both are forbidden.
1197@item
1198 Is the patch attached to the email you send?
1199@item
1200 Is the mime type of the patch correct? It should be text/x-diff or
1201 text/x-patch or at least text/plain and not application/octet-stream.
1202@item
1203 If the patch fixes a bug, did you provide a verbose analysis of the bug?
1204@item
1205 If the patch fixes a bug, did you provide enough information, including
1206 a sample, so the bug can be reproduced and the fix can be verified?
1207 Note please do not attach samples >100k to mails but rather provide a
0fa5f24c 1208 URL, you can upload to ftp://upload.ffmpeg.org
d0e1cd3d
DB
1209@item
1210 Did you provide a verbose summary about what the patch does change?
1211@item
1212 Did you provide a verbose explanation why it changes things like it does?
1213@item
1214 Did you provide a verbose summary of the user visible advantages and
1215 disadvantages if the patch is applied?
1216@item
1217 Did you provide an example so we can verify the new feature added by the
1218 patch easily?
1219@item
1220 If you added a new file, did you insert a license header? It should be
1221 taken from FFmpeg, not randomly copied and pasted from somewhere else.
1222@item
1223 You should maintain alphabetical order in alphabetically ordered lists as
1224 long as doing so does not break API/ABI compatibility.
1225@item
1226 Lines with similar content should be aligned vertically when doing so
1227 improves readability.
1228@item
1229 Did you provide a suggestion for a clear commit log message?
1230@end enumerate
1231
1232@section Patch review process
1233
1234All patches posted to ffmpeg-devel will be reviewed, unless they contain a
1235clear note that the patch is not for SVN.
1236Reviews and comments will be posted as replies to the patch on the
1237mailing list. The patch submitter then has to take care of every comment,
1238that can be by resubmitting a changed patch or by discussion. Resubmitted
1239patches will themselves be reviewed like any other patch. If at some point
1240a patch passes review with no comments then it is approved, that can for
1241simple and small patches happen immediately while large patches will generally
1242have to be changed and reviewed many times before they are approved.
1243After a patch is approved it will be committed to the repository.
1244
1245We will review all submitted patches, but sometimes we are quite busy so
1246especially for large patches this can take several weeks.
1247
1248When resubmitting patches, please do not make any significant changes
1249not related to the comments received during review. Such patches will
1250be rejected. Instead, submit significant changes or new features as
1251separate patches.
1252
1253@section Regression tests
1254
1255Before submitting a patch (or committing to the repository), you should at least
1256test that you did not break anything.
1257
1258The regression tests build a synthetic video stream and a synthetic
1259audio stream. These are then encoded and decoded with all codecs or
1260formats. The CRC (or MD5) of each generated file is recorded in a
1261result file. A 'diff' is launched to compare the reference results and
1262the result file.
1263
1264The regression tests then go on to test the FFserver code with a
1265limited set of streams. It is important that this step runs correctly
1266as well.
1267
1268Run 'make test' to test all the codecs and formats.
1269
1270Run 'make fulltest' to test all the codecs, formats and FFserver.
1271
1272[Of course, some patches may change the results of the regression tests. In
1273this case, the reference results of the regression tests shall be modified
1274accordingly].
1275
1276@bye