RA144: work around gcc bug/oddity on ARM
[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
64c2f20a 236@item .Y.U.V @tab X @tab X @tab one raw file per component
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237@item animated GIF @tab X @tab X @tab Only uncompressed GIFs are generated.
238@item JPEG @tab X @tab X @tab Progressive JPEG is not supported.
9a77d59a 239@item JPEG 2000 @tab @tab E @tab decoding supported through external library libopenjpeg
d0e1cd3d 240@item PAM @tab X @tab X @tab PAM is a PNM extension with alpha support.
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241@item PCX @tab @tab X @tab PC Paintbrush
242@item PGM, PPM @tab X @tab X
d0e1cd3d 243@item PGMYUV @tab X @tab X @tab PGM with U and V components in YUV 4:2:0
0a91f4ee 244@item PNG @tab X @tab X @tab 2/4 bpp not supported yet
d0e1cd3d 245@item PTX @tab @tab X @tab V.Flash PTX format
d1928ac1 246@item RAS @tab @tab X @tab Sun Rasterfile
3d172fb5 247@item SGI @tab X @tab X @tab SGI RGB image format
3d172fb5 248@item Targa @tab @tab X @tab Targa (.TGA) image format
64c2f20a 249@item TIFF @tab X @tab X @tab YUV, JPEG and some extension is not supported yet.
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250@end multitable
251
252@code{X} means that encoding (resp. decoding) is supported.
253
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254@code{E} means that support is provided through an external library.
255
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256@section Video Codecs
257
258@multitable @columnfractions .4 .1 .1 .4
b3de4544 259@item Name @tab Encoding @tab Decoding @tab Comments
d66d8b83 260@item 4X Video @tab @tab X
d698c5d3 261 @tab Used in certain computer games.
913c3e2c 262@item American Laser Games MM @tab @tab X
d698c5d3 263 @tab Used in games like Mad Dog McCree.
d66d8b83 264@item AMV @tab @tab X
d698c5d3 265 @tab Used in Chinese MP3 players.
d66d8b83 266@item Apple Animation @tab X @tab X
d698c5d3 267 @tab fourcc: 'rle '
d66d8b83 268@item Apple Graphics @tab @tab X
d698c5d3 269 @tab fourcc: 'smc '
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270@item Apple MJPEG-B @tab @tab X
271@item Apple QuickDraw @tab @tab X
d698c5d3 272 @tab fourcc: qdrw
d66d8b83 273@item Apple Video @tab @tab X
d698c5d3 274 @tab fourcc: rpza
d66d8b83 275@item Asus v1 @tab X @tab X
d698c5d3 276 @tab fourcc: ASV1
d66d8b83 277@item Asus v2 @tab X @tab X
d698c5d3 278 @tab fourcc: ASV2
d66d8b83 279@item ATI VCR1 @tab @tab X
d698c5d3 280 @tab fourcc: VCR1
d66d8b83 281@item ATI VCR2 @tab @tab X
d698c5d3 282 @tab fourcc: VCR2
d66d8b83 283@item Autodesk RLE @tab @tab X
d698c5d3 284 @tab fourcc: AASC
d66d8b83 285@item AVID DNxHD @tab X @tab X
d698c5d3 286 @tab aka SMPTE VC3
bac4c85c 287@item AVS video @tab @tab X
d698c5d3 288 @tab Video encoding used by the Creature Shock game.
d66d8b83 289@item Bethsoft VID @tab @tab X
d698c5d3 290 @tab Used in some games from Bethesda Softworks.
bac4c85c 291@item C93 video @tab @tab X
d698c5d3 292 @tab Codec used in Cyberia game.
d66d8b83 293@item CamStudio @tab @tab X
d698c5d3 294 @tab fourcc: CSCD
bac4c85c 295@item Cin video @tab @tab X
d698c5d3 296 @tab Codec used in Delphine Software games.
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297@item Cinepak @tab @tab X
298@item Cirrus Logic AccuPak @tab @tab X
d698c5d3 299 @tab fourcc: CLJR
d66d8b83 300@item Creative YUV @tab @tab X
d698c5d3 301 @tab fourcc: CYUV
82ced5a9 302@item Dirac @tab E @tab E
360f980b 303 @tab supported through external libdirac/libschroedinger libraries
d66d8b83 304@item Duck TrueMotion v1 @tab @tab X
d698c5d3 305 @tab fourcc: DUCK
d66d8b83 306@item Duck TrueMotion v2 @tab @tab X
d698c5d3 307 @tab fourcc: TM20
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308@item DV @tab X @tab X
309@item DXA Video @tab @tab X
d698c5d3 310 @tab Codec originally used in Feeble Files game.
d66d8b83 311@item Electronic Arts CMV @tab @tab X
d698c5d3 312 @tab Used in NHL 95 game.
cfc78718 313@item Electronic Arts TGV @tab @tab X
42b30357 314@item Electronic Arts TGQ @tab @tab X
d8964f3a 315@item Electronic Arts TQI @tab @tab X
d66d8b83 316@item FFmpeg Video 1 @tab X @tab X
d698c5d3 317 @tab experimental lossless codec (fourcc: FFV1)
d66d8b83 318@item Flash Screen Video @tab X @tab X
d698c5d3 319 @tab fourcc: FSV1
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320@item FLIC video @tab @tab X
321@item FLV @tab X @tab X
d698c5d3 322 @tab Sorenson H.263 used in Flash
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323@item Fraps FPS1 @tab @tab X
324@item H.261 @tab X @tab X
325@item H.263(+) @tab X @tab X
d698c5d3 326 @tab also known as RealVideo 1.0
82ced5a9 327@item H.264 @tab E @tab X
360f980b 328 @tab encoding supported through external library libx264
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329@item HuffYUV @tab X @tab X
330@item IBM Ultimotion @tab @tab X
d698c5d3 331 @tab fourcc: ULTI
bac4c85c 332@item id Cinematic video @tab @tab X
d698c5d3 333 @tab Used in Quake II.
d66d8b83 334@item id RoQ @tab X @tab X
d698c5d3 335 @tab Used in Quake III, Jedi Knight 2, other computer games.
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336@item Intel Indeo 3 @tab @tab X
337@item Interplay Video @tab @tab X
d698c5d3 338 @tab Used in Interplay .MVE files.
d66d8b83 339@item JPEG-LS @tab X @tab X
d698c5d3 340 @tab fourcc: MJLS, lossless and near-lossless is supported.
d66d8b83 341@item KMVC @tab @tab X
d698c5d3 342 @tab Codec used in Worms games.
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343@item LOCO @tab @tab X
344@item lossless MJPEG @tab X @tab X
345@item Microsoft RLE @tab @tab X
346@item Microsoft Video-1 @tab @tab X
347@item Mimic @tab @tab X
d698c5d3 348 @tab Used in MSN Messenger Webcam streams.
d66d8b83 349@item Miro VideoXL @tab @tab X
d698c5d3 350 @tab fourcc: VIXL
d66d8b83 351@item MJPEG @tab X @tab X
822cc8f7 352@item Motion Pixels Video @tab @tab X
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353@item MPEG-1 @tab X @tab X
354@item MPEG-2 @tab X @tab X
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355@item MPEG-4 @tab X @tab X
356@item MSMPEG4 V1 @tab X @tab X
357@item MSMPEG4 V2 @tab X @tab X
358@item MSMPEG4 V3 @tab X @tab X
d66d8b83 359@item MSZH @tab @tab X
d698c5d3 360 @tab Part of LCL
d66d8b83 361@item On2 VP3 @tab @tab X
d698c5d3 362 @tab still experimental
d66d8b83 363@item On2 VP5 @tab @tab X
d698c5d3 364 @tab fourcc: VP50
d66d8b83 365@item On2 VP6 @tab @tab X
d698c5d3 366 @tab fourcc: VP60,VP61,VP62
d66d8b83 367@item planar RGB @tab @tab X
d698c5d3 368 @tab fourcc: 8BPS
d66d8b83 369@item QPEG @tab @tab X
d698c5d3 370 @tab fourccs: QPEG, Q1.0, Q1.1
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371@item RealVideo 1.0 @tab X @tab X
372@item RealVideo 2.0 @tab X @tab X
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373@item RealVideo 3.0 @tab @tab X
374 @tab still far from ideal
11c0f9ec 375@item RealVideo 4.0 @tab @tab X
d66d8b83 376@item Renderware TXD @tab @tab X
d698c5d3 377 @tab Texture dictionaries used by the Renderware Engine.
d66d8b83 378@item RTjpeg @tab @tab X
d698c5d3 379 @tab Video encoding used in NuppelVideo files.
bac4c85c 380@item Smacker video @tab @tab X
d698c5d3 381 @tab Video encoding used in Smacker.
d66d8b83 382@item Snow @tab X @tab X
d698c5d3 383 @tab experimental wavelet codec (fourcc: SNOW)
831ec935 384@item Sony PlayStation MDEC @tab @tab X
d66d8b83 385@item Sorenson Video 1 @tab X @tab X
d698c5d3 386 @tab fourcc: SVQ1
d66d8b83 387@item Sorenson Video 3 @tab @tab X
d698c5d3 388 @tab fourcc: SVQ3
d66d8b83 389@item Sunplus MJPEG @tab @tab X
d698c5d3 390 @tab fourcc: SP5X
d66d8b83 391@item TechSmith Camtasia @tab @tab X
d698c5d3 392 @tab fourcc: TSCC
82ced5a9 393@item Theora @tab E @tab X
360f980b 394 @tab encoding supported through external library libtheora
d66d8b83 395@item THP @tab @tab X
d698c5d3 396 @tab Used on the Nintendo GameCube.
bac4c85c 397@item Tiertex Seq video @tab @tab X
d698c5d3 398 @tab Codec used in DOS CD-ROM FlashBack game.
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399@item VC-1 @tab @tab X
400@item VMD Video @tab @tab X
d698c5d3 401 @tab Used in Sierra VMD files.
d66d8b83 402@item VMware Video @tab @tab X
d698c5d3 403 @tab Codec used in videos captured by VMware.
d0e1cd3d 404@item Westwood VQA @tab @tab X
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405@item Winnov WNV1 @tab @tab X
406@item WMV7 @tab X @tab X
407@item WMV8 @tab X @tab X
408@item WMV9 @tab @tab X
d698c5d3 409 @tab not completely working
d66d8b83 410@item Xan/WC3 @tab @tab X
d698c5d3 411 @tab Used in Wing Commander III .MVE files.
39271be4 412@item YAMAHA SMAF @tab X @tab X
d66d8b83 413@item ZLIB @tab X @tab X
d698c5d3 414 @tab part of LCL, encoder experimental
d66d8b83 415@item ZMBV @tab X @tab X
d698c5d3 416 @tab Encoder works only in PAL8.
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417@end multitable
418
419@code{X} means that encoding (resp. decoding) is supported.
420
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421@code{E} means that support is provided through an external library.
422
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423@section Audio Codecs
424
485ec4f1 425@multitable @columnfractions .4 .1 .1 .4
b3de4544 426@item Name @tab Encoding @tab Decoding @tab Comments
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427@item 4X IMA ADPCM @tab @tab X
428@item 8SVX audio @tab @tab X
82ced5a9 429@item AAC @tab E @tab X
360f980b 430 @tab encoding supported through external library libfaac
16d81b27 431@item AC-3 @tab IX @tab IX
82ced5a9 432@item AMR-NB @tab E @tab E
360f980b 433 @tab supported through external library libamrnb
82ced5a9 434@item AMR-WB @tab E @tab E
360f980b 435 @tab supported through external library libamrwb
16d81b27 436@item AMV IMA ADPCM @tab @tab X
d698c5d3 437 @tab Used in AMV files
833e90dd 438@item Apple lossless audio @tab X @tab X
d698c5d3 439 @tab QuickTime fourcc 'alac'
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440@item Apple MACE 3 @tab @tab X
441@item Apple MACE 6 @tab @tab X
442@item ATRAC 3 @tab @tab X
443@item CD-ROM XA ADPCM @tab @tab X
bac4c85c 444@item Cin audio @tab @tab X
d698c5d3 445 @tab Codec used in Delphine Software International games.
16d81b27 446@item Creative ADPCM @tab @tab X
d698c5d3 447 @tab 16 -> 4, 8 -> 4, 8 -> 3, 8 -> 2
16d81b27 448@item CRI ADX ADPCM @tab X @tab X
d698c5d3 449 @tab Used in Sega Dreamcast games.
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450@item DSP Group TrueSpeech @tab @tab X
451@item DTS Coherent Audio @tab @tab X
452@item Duck DK3 IMA ADPCM @tab @tab X
d698c5d3 453 @tab Used in some Sega Saturn console games.
16d81b27 454@item Duck DK4 IMA ADPCM @tab @tab X
d698c5d3 455 @tab Used in some Sega Saturn console games.
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456@item DV audio @tab @tab X
457@item Electronic Arts ADPCM @tab @tab X
d698c5d3 458 @tab Used in various EA titles.
44723c84 459@item Enhanced AC-3 @tab @tab X
9a584db4 460@item FLAC lossless audio @tab IX @tab X
16d81b27 461@item G.726 ADPCM @tab X @tab X
82ced5a9 462@item GSM @tab E @tab E
3f33271a 463 @tab supported through external library libgsm
82ced5a9 464@item GSM_MS @tab E @tab E
3f33271a 465 @tab supported through external library libgsm
16d81b27 466@item id RoQ DPCM @tab X @tab X
d698c5d3 467 @tab Used in Quake III, Jedi Knight 2, other computer games.
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468@item Intel Music Coder @tab @tab X
469@item Interplay MVE DPCM @tab @tab X
d698c5d3 470 @tab Used in various Interplay computer games.
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471@item ISS IMA ADPCM @tab @tab X
472 @tab Used in FunCom games.
16d81b27 473@item MAXIS EA ADPCM @tab @tab X
d698c5d3 474 @tab Used in Sim City 3000.
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475@item Microsoft ADPCM @tab X @tab X
476@item MLP/TrueHD @tab @tab X
d698c5d3 477 @tab Used in DVD-Audio and Blu-Ray discs.
16d81b27 478@item Monkey's Audio @tab @tab X
d698c5d3 479 @tab Only versions 3.97-3.99 are supported.
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480@item MPEG audio layer 3 @tab E @tab IX
481 @tab encoding supported through external library LAME
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482@item MPEG audio layer 2 @tab IX @tab IX
483@item MS IMA ADPCM @tab X @tab X
484@item Musepack @tab @tab X
d698c5d3 485 @tab SV7 and SV8 are supported.
755ba886 486@item Nellymoser ASAO @tab X @tab X
73b458e3 487@item QCELP / PureVoice @tab @tab X
16d81b27 488@item Qdesign QDM2 @tab @tab X
d698c5d3 489 @tab There are still some distortions.
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490@item QT IMA ADPCM @tab X @tab X
491@item RA144 @tab @tab X
d698c5d3 492 @tab Real 14400 bit/s codec
16d81b27 493@item RA288 @tab @tab X
d698c5d3 494 @tab Real 28800 bit/s codec
575a5bf2 495@item RADnet @tab IX @tab IX
a692130f 496 @tab Real low bitrate AC-3 codec
16d81b27 497@item Real COOK @tab @tab X
d698c5d3 498 @tab All versions except 5.1 are supported.
bac4c85c 499@item Shorten @tab @tab X
16d81b27 500@item Sierra Online DPCM @tab @tab X
d698c5d3 501 @tab Used in Sierra Online game audio files.
bac4c85c 502@item Smacker audio @tab @tab X
16d81b27 503@item SMJPEG IMA ADPCM @tab @tab X
d698c5d3 504 @tab Used in certain Loki game ports.
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505@item Sonic @tab X @tab X
506 @tab experimental codec
507@item Sonic lossless @tab X @tab X
508 @tab experimental codec
82ced5a9 509@item Speex @tab @tab E
360f980b 510 @tab supported through external library libspeex
16d81b27 511@item THP ADPCM @tab @tab X
d698c5d3 512 @tab Used on the Nintendo GameCube.
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513@item True Audio (TTA) @tab @tab X
514@item Vorbis @tab X @tab X
bac4c85c 515@item WavPack @tab @tab X
16d81b27 516@item Westwood Studios IMA ADPCM @tab @tab X
d698c5d3 517 @tab Used in Westwood Studios games like Command and Conquer.
bac4c85c 518@item WMA v1/v2 @tab X @tab X
16d81b27 519@item Xan DPCM @tab @tab X
d698c5d3 520 @tab Used in Origin's Wing Commander IV AVI files.
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521@end multitable
522
523@code{X} means that encoding (resp. decoding) is supported.
524
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525@code{E} means that support is provided through an external library.
526
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527@code{I} means that an integer-only version is available, too (ensures high
528performance on systems without hardware floating point support).
529
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530@section Subtitle Formats
531
485ec4f1 532@multitable @columnfractions .4 .1 .1 .1 .1 .1
9afc2917 533@item Name @tab Muxing @tab Demuxing @tab Encoding @tab Decoding
913c3e2c 534@item SSA/ASS @tab X @tab X
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535@item DVB @tab X @tab X @tab X @tab X
536@item DVD @tab X @tab X @tab X @tab X
537@item XSUB @tab @tab @tab @tab X
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538@end multitable
539
540@code{X} means that the feature is supported.
541
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542@section Network Protocols
543
544@multitable @columnfractions .4 .1 .1 .1 .1 .1
545@item Name @tab Support
546@item file @tab X
547@item Gopher @tab X
548@item HTTP @tab X
549@item pipe @tab X
550@item RTP @tab X
551@item TCP @tab X
552@item UDP @tab X
553@end multitable
554
555@code{X} means that the protocol is supported.
556
557
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558@chapter Platform Specific information
559
560@section BSD
561
562BSD make will not build FFmpeg, you need to install and use GNU Make
563(@file{gmake}).
564
565@section Windows
566
46a845d0 567To get help and instructions for building FFmpeg under Windows, check out
d0e1cd3d 568the FFmpeg Windows Help Forum at
ab5ce4ae 569@url{http://ffmpeg.arrozcru.org/}.
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570
571@subsection Native Windows compilation
572
c1989552 573FFmpeg can be built to run natively on Windows using the MinGW tools. Install
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574the latest versions of MSYS and MinGW from @url{http://www.mingw.org/}.
575You can find detailed installation
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576instructions in the download section and the FAQ.
577
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578FFmpeg does not build out-of-the-box with the packages the automated MinGW
579installer provides. It also requires coreutils to be installed and many other
580packages updated to the latest version. The minimum version for some packages
581are listed below:
582
583@itemize
584@item bash 3.1
585@item msys-make 3.81-2 (note: not mingw32-make)
2014b51c 586@item w32api 3.13
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587@item mingw-runtime 3.15
588@end itemize
589
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590You will also need to pass @code{-fno-common} to the compiler to work around
591a GCC bug (see @url{http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37216}).
592
c1989552 593Within the MSYS shell, configure and make with:
d0e1cd3d 594
c1989552 595@example
0f898714 596./configure --enable-memalign-hack --extra-cflags=-fno-common
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597make
598make install
599@end example
d0e1cd3d 600
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601This will install @file{ffmpeg.exe} along with many other development files
602to @file{/usr/local}. You may specify another install path using the
603@code{--prefix} option in @file{configure}.
d0e1cd3d 604
c1989552 605Notes:
d0e1cd3d 606
c1989552 607@itemize
d0e1cd3d 608
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609@item In order to compile vhooks, you must have a POSIX-compliant libdl in
610your MinGW system. Get dlfcn-win32 from
611@url{http://code.google.com/p/dlfcn-win32}.
d0e1cd3d 612
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613@item In order to compile FFplay, you must have the MinGW development library
614of SDL. Get it from @url{http://www.libsdl.org}.
615Edit the @file{bin/sdl-config} script so that it points to the correct prefix
616where SDL was installed. Verify that @file{sdl-config} can be launched from
617the MSYS command line.
d0e1cd3d 618
d0e1cd3d 619@item By using @code{./configure --enable-shared} when configuring FFmpeg,
c1989552 620you can build libavutil, libavcodec and libavformat as DLLs.
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621
622@end itemize
623
c1989552 624@subsection Microsoft Visual C++ compatibility
d0e1cd3d 625
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626As stated in the FAQ, FFmpeg will not compile under MSVC++. However, if you
627want to use the libav* libraries in your own applications, you can still
628compile those applications using MSVC++. But the libav* libraries you link
629to @emph{must} be built with MinGW. However, you will not be able to debug
630inside the libav* libraries, since MSVC++ does not recognize the debug
631symbols generated by GCC.
632We strongly recommend you to move over from MSVC++ to MinGW tools.
d0e1cd3d 633
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634This description of how to use the FFmpeg libraries with MSVC++ is based on
635Microsoft Visual C++ 2005 Express Edition. If you have a different version,
636you might have to modify the procedures slightly.
d0e1cd3d 637
c1989552 638@subsubsection Using static libraries
d0e1cd3d 639
c1989552 640Assuming you have just built and installed FFmpeg in @file{/usr/local}.
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641
642@enumerate
643
644@item Create a new console application ("File / New / Project") and then
645select "Win32 Console Application". On the appropriate page of the
646Application Wizard, uncheck the "Precompiled headers" option.
647
648@item Write the source code for your application, or, for testing, just
649copy the code from an existing sample application into the source file
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650that MSVC++ has already created for you. For example, you can copy
651@file{output_example.c} from the FFmpeg distribution.
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652
653@item Open the "Project / Properties" dialog box. In the "Configuration"
654combo box, select "All Configurations" so that the changes you make will
655affect both debug and release builds. In the tree view on the left hand
656side, select "C/C++ / General", then edit the "Additional Include
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657Directories" setting to contain the path where the FFmpeg includes were
658installed (i.e. @file{c:\msys\1.0\local\include}).
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659Do not add MinGW's include directory here, or the include files will
660conflict with MSVC's.
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661
662@item Still in the "Project / Properties" dialog box, select
663"Linker / General" from the tree view and edit the
664"Additional Library Directories" setting to contain the @file{lib}
665directory where FFmpeg was installed (i.e. @file{c:\msys\1.0\local\lib}),
666the directory where MinGW libs are installed (i.e. @file{c:\mingw\lib}),
667and the directory where MinGW's GCC libs are installed
668(i.e. @file{C:\mingw\lib\gcc\mingw32\4.2.1-sjlj}). Then select
669"Linker / Input" from the tree view, and add the files @file{libavformat.a},
670@file{libavcodec.a}, @file{libavutil.a}, @file{libmingwex.a},
671@file{libgcc.a}, and any other libraries you used (i.e. @file{libz.a})
672to the end of "Additional Dependencies".
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673
674@item Now, select "C/C++ / Code Generation" from the tree view. Select
675"Debug" in the "Configuration" combo box. Make sure that "Runtime
676Library" is set to "Multi-threaded Debug DLL". Then, select "Release" in
677the "Configuration" combo box and make sure that "Runtime Library" is
678set to "Multi-threaded DLL".
679
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680@item Click "OK" to close the "Project / Properties" dialog box.
681
682@item MSVC++ lacks some C99 header files that are fundamental for FFmpeg.
683Get msinttypes from @url{http://code.google.com/p/msinttypes/downloads/list}
684and install it in MSVC++'s include directory
685(i.e. @file{C:\Program Files\Microsoft Visual Studio 8\VC\include}).
686
687@item MSVC++ also does not understand the @code{inline} keyword used by
688FFmpeg, so you must add this line before @code{#include}ing libav*:
689@example
690#define inline _inline
691@end example
692
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693@item Build your application, everything should work.
694
695@end enumerate
696
697@subsubsection Using shared libraries
698
699This is how to create DLL and LIB files that are compatible with MSVC++:
700
701@enumerate
702
703@item Add a call to @file{vcvars32.bat} (which sets up the environment
704variables for the Visual C++ tools) as the first line of @file{msys.bat}.
705The standard location for @file{vcvars32.bat} is
706@file{C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat},
707and the standard location for @file{msys.bat} is @file{C:\msys\1.0\msys.bat}.
708If this corresponds to your setup, add the following line as the first line
709of @file{msys.bat}:
710
711@example
712call "C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat"
713@end example
714
715Alternatively, you may start the @file{Visual Studio 2005 Command Prompt},
716and run @file{c:\msys\1.0\msys.bat} from there.
717
718@item Within the MSYS shell, run @code{lib.exe}. If you get a help message
719from @file{Microsoft (R) Library Manager}, this means your environment
720variables are set up correctly, the @file{Microsoft (R) Library Manager}
721is on the path and will be used by FFmpeg to create
722MSVC++-compatible import libraries.
723
724@item Build FFmpeg with
725
726@example
727./configure --enable-shared --enable-memalign-hack
728make
729make install
730@end example
731
732Your install path (@file{/usr/local/} by default) should now have the
733necessary DLL and LIB files under the @file{bin} directory.
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734
735@end enumerate
736
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737To use those files with MSVC++, do the same as you would do with
738the static libraries, as described above. But in Step 4,
739you should only need to add the directory where the LIB files are installed
740(i.e. @file{c:\msys\usr\local\bin}). This is not a typo, the LIB files are
741installed in the @file{bin} directory. And instead of adding @file{libxx.a}
742files, you should add @file{avcodec.lib}, @file{avformat.lib}, and
743@file{avutil.lib}. There should be no need for @file{libmingwex.a},
744@file{libgcc.a}, and @file{wsock32.lib}, nor any other external library
745statically linked into the DLLs. The @file{bin} directory contains a bunch
746of DLL files, but the ones that are actually used to run your application
747are the ones with a major version number in their filenames
748(i.e. @file{avcodec-51.dll}).
749
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750@subsection Cross compilation for Windows with Linux
751
752You must use the MinGW cross compilation tools available at
753@url{http://www.mingw.org/}.
754
755Then configure FFmpeg with the following options:
756@example
757./configure --target-os=mingw32 --cross-prefix=i386-mingw32msvc-
758@end example
759(you can change the cross-prefix according to the prefix chosen for the
760MinGW tools).
761
762Then you can easily test FFmpeg with Wine
763(@url{http://www.winehq.com/}).
764
765@subsection Compilation under Cygwin
766
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767The main issue with the 1.5.x Cygwin versions is that newlib, its C library,
768does not contain llrint(). You need to upgrade to the unstable 1.7.x versions,
769or leverage the implementation in MinGW (as explained below).
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770
771Just install your Cygwin with all the "Base" packages, plus the
772following "Devel" ones:
773@example
f496ab12 774binutils, gcc-core, make, subversion, mingw-runtime, diffutils
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775@end example
776
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777The experimental gcc4 package is still buggy, hence please
778use the official gcc 3.4.4 or a 4.2.x compiled from source by yourself.
779
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780Install the current binutils-20080624-2 as they work fine (the old
781binutils-20060709-1 proved buggy on shared builds).
d0e1cd3d 782
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783Then create a small library that just contains llrint():
784
785@example
786ar x /usr/lib/mingw/libmingwex.a llrint.o
787ar cq /usr/local/lib/libllrint.a llrint.o
788@end example
789
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790Then run
791
792@example
29c3d42b 793./configure --enable-static --disable-shared --extra-ldflags='-L /usr/local/lib' --extra-libs='-l llrint'
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794@end example
795
796to make a static build or
797
798@example
29c3d42b 799./configure --enable-shared --disable-static --extra-ldflags='-L /usr/local/lib' --extra-libs='-l llrint'
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800@end example
801
802to build shared libraries.
803
804If you want to build FFmpeg with additional libraries, download Cygwin
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805"Devel" packages for Ogg and Vorbis from any Cygwin packages repository:
806@example
807libogg-devel, libvorbis-devel
808@end example
809
810These library packages are only available from Cygwin Ports
be8497b0 811(@url{http://sourceware.org/cygwinports/}) :
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812
813@example
814yasm, libSDL-devel, libdirac-devel, libfaac-devel, libfaad-devel, libgsm-devel,
815libmp3lame-devel, libschroedinger1.0-devel, speex-devel, libtheora-devel,
816libxvidcore-devel
817@end example
818
819The recommendation for libnut and x264 is to build them from source by
820yourself, as they evolve too quickly for Cygwin Ports to be up to date.
d0e1cd3d 821
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822Cygwin 1.7.x has IPv6 support. You can add IPv6 to Cygwin 1.5.x by means
823of the @code{libgetaddrinfo-devel} package, available at Cygwin Ports.
824
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825@subsection Crosscompilation for Windows under Cygwin
826
827With Cygwin you can create Windows binaries that do not need the cygwin1.dll.
828
829Just install your Cygwin as explained before, plus these additional
830"Devel" packages:
831@example
832gcc-mingw-core, mingw-runtime, mingw-zlib
833@end example
834
835and add some special flags to your configure invocation.
836
837For a static build run
838@example
839./configure --target-os=mingw32 --enable-memalign-hack --enable-static --disable-shared --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
840@end example
841
842and for a build with shared libraries
843@example
844./configure --target-os=mingw32 --enable-memalign-hack --enable-shared --disable-static --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
845@end example
846
847@section BeOS
848
5f757b85 849BeOS support is broken in mysterious ways.
d0e1cd3d 850
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851@section OS/2
852
853For information about compiling FFmpeg on OS/2 see
854@url{http://www.edm2.com/index.php/FFmpeg}.
855
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856@chapter Developers Guide
857
858@section API
859@itemize @bullet
860@item libavcodec is the library containing the codecs (both encoding and
861decoding). Look at @file{libavcodec/apiexample.c} to see how to use it.
862
863@item libavformat is the library containing the file format handling (mux and
864demux code for several formats). Look at @file{ffplay.c} to use it in a
865player. See @file{output_example.c} to use it to generate audio or video
866streams.
867
868@end itemize
869
870@section Integrating libavcodec or libavformat in your program
871
872You can integrate all the source code of the libraries to link them
873statically to avoid any version problem. All you need is to provide a
874'config.mak' and a 'config.h' in the parent directory. See the defines
875generated by ./configure to understand what is needed.
876
877You can use libavcodec or libavformat in your commercial program, but
878@emph{any patch you make must be published}. The best way to proceed is
879to send your patches to the FFmpeg mailing list.
880
881@node Coding Rules
882@section Coding Rules
883
884FFmpeg is programmed in the ISO C90 language with a few additional
885features from ISO C99, namely:
886@itemize @bullet
887@item
888the @samp{inline} keyword;
889@item
890@samp{//} comments;
891@item
892designated struct initializers (@samp{struct s x = @{ .i = 17 @};})
893@item
894compound literals (@samp{x = (struct s) @{ 17, 23 @};})
895@end itemize
896
897These features are supported by all compilers we care about, so we will not
898accept patches to remove their use unless they absolutely do not impair
899clarity and performance.
900
901All code must compile with GCC 2.95 and GCC 3.3. Currently, FFmpeg also
902compiles with several other compilers, such as the Compaq ccc compiler
903or Sun Studio 9, and we would like to keep it that way unless it would
904be exceedingly involved. To ensure compatibility, please do not use any
905additional C99 features or GCC extensions. Especially watch out for:
906@itemize @bullet
907@item
908mixing statements and declarations;
909@item
910@samp{long long} (use @samp{int64_t} instead);
911@item
912@samp{__attribute__} not protected by @samp{#ifdef __GNUC__} or similar;
913@item
914GCC statement expressions (@samp{(x = (@{ int y = 4; y; @})}).
915@end itemize
916
917Indent size is 4.
918The presentation is the one specified by 'indent -i4 -kr -nut'.
919The TAB character is forbidden outside of Makefiles as is any
920form of trailing whitespace. Commits containing either will be
921rejected by the Subversion repository.
922
923The main priority in FFmpeg is simplicity and small code size in order to
924minimize the bug count.
925
926Comments: Use the JavaDoc/Doxygen
927format (see examples below) so that code documentation
928can be generated automatically. All nontrivial functions should have a comment
929above them explaining what the function does, even if it is just one sentence.
930All structures and their member variables should be documented, too.
931@example
932/**
933 * @@file mpeg.c
934 * MPEG codec.
935 * @@author ...
936 */
937
938/**
939 * Summary sentence.
940 * more text ...
941 * ...
942 */
943typedef struct Foobar@{
944 int var1; /**< var1 description */
945 int var2; ///< var2 description
946 /** var3 description */
947 int var3;
948@} Foobar;
949
950/**
951 * Summary sentence.
952 * more text ...
953 * ...
954 * @@param my_parameter description of my_parameter
955 * @@return return value description
956 */
957int myfunc(int my_parameter)
958...
959@end example
960
961fprintf and printf are forbidden in libavformat and libavcodec,
962please use av_log() instead.
963
964Casts should be used only when necessary. Unneeded parentheses
965should also be avoided if they don't make the code easier to understand.
966
967@section Development Policy
968
969@enumerate
970@item
971 Contributions should be licensed under the LGPL 2.1, including an
972 "or any later version" clause, or the MIT license. GPL 2 including
973 an "or any later version" clause is also acceptable, but LGPL is
974 preferred.
975@item
976 You must not commit code which breaks FFmpeg! (Meaning unfinished but
977 enabled code which breaks compilation or compiles but does not work or
978 breaks the regression tests)
979 You can commit unfinished stuff (for testing etc), but it must be disabled
980 (#ifdef etc) by default so it does not interfere with other developers'
981 work.
982@item
983 You do not have to over-test things. If it works for you, and you think it
984 should work for others, then commit. If your code has problems
985 (portability, triggers compiler bugs, unusual environment etc) they will be
986 reported and eventually fixed.
987@item
988 Do not commit unrelated changes together, split them into self-contained
989 pieces. Also do not forget that if part B depends on part A, but A does not
990 depend on B, then A can and should be committed first and separate from B.
991 Keeping changes well split into self-contained parts makes reviewing and
992 understanding them on the commit log mailing list easier. This also helps
993 in case of debugging later on.
994 Also if you have doubts about splitting or not splitting, do not hesitate to
995 ask/discuss it on the developer mailing list.
996@item
997 Do not change behavior of the program (renaming options etc) without
998 first discussing it on the ffmpeg-devel mailing list. Do not remove
999 functionality from the code. Just improve!
1000
1001 Note: Redundant code can be removed.
1002@item
1003 Do not commit changes to the build system (Makefiles, configure script)
1004 which change behavior, defaults etc, without asking first. The same
1005 applies to compiler warning fixes, trivial looking fixes and to code
1006 maintained by other developers. We usually have a reason for doing things
1007 the way we do. Send your changes as patches to the ffmpeg-devel mailing
1008 list, and if the code maintainers say OK, you may commit. This does not
1009 apply to files you wrote and/or maintain.
1010@item
1011 We refuse source indentation and other cosmetic changes if they are mixed
1012 with functional changes, such commits will be rejected and removed. Every
1013 developer has his own indentation style, you should not change it. Of course
1014 if you (re)write something, you can use your own style, even though we would
1015 prefer if the indentation throughout FFmpeg was consistent (Many projects
1016 force a given indentation style - we do not.). If you really need to make
1017 indentation changes (try to avoid this), separate them strictly from real
1018 changes.
1019
1020 NOTE: If you had to put if()@{ .. @} over a large (> 5 lines) chunk of code,
1021 then either do NOT change the indentation of the inner part within (do not
1022 move it to the right)! or do so in a separate commit
1023@item
1024 Always fill out the commit log message. Describe in a few lines what you
1025 changed and why. You can refer to mailing list postings if you fix a
1026 particular bug. Comments such as "fixed!" or "Changed it." are unacceptable.
1027@item
1028 If you apply a patch by someone else, include the name and email address in
1029 the log message. Since the ffmpeg-cvslog mailing list is publicly
1030 archived you should add some SPAM protection to the email address. Send an
1031 answer to ffmpeg-devel (or wherever you got the patch from) saying that
1032 you applied the patch.
1033@item
1034 When applying patches that have been discussed (at length) on the mailing
1035 list, reference the thread in the log message.
1036@item
1037 Do NOT commit to code actively maintained by others without permission.
1038 Send a patch to ffmpeg-devel instead. If no one answers within a reasonable
1039 timeframe (12h for build failures and security fixes, 3 days small changes,
1040 1 week for big patches) then commit your patch if you think it is OK.
1041 Also note, the maintainer can simply ask for more time to review!
1042@item
1043 Subscribe to the ffmpeg-cvslog mailing list. The diffs of all commits
1044 are sent there and reviewed by all the other developers. Bugs and possible
1045 improvements or general questions regarding commits are discussed there. We
1046 expect you to react if problems with your code are uncovered.
1047@item
1048 Update the documentation if you change behavior or add features. If you are
1049 unsure how best to do this, send a patch to ffmpeg-devel, the documentation
1050 maintainer(s) will review and commit your stuff.
1051@item
1052 Try to keep important discussions and requests (also) on the public
1053 developer mailing list, so that all developers can benefit from them.
1054@item
1055 Never write to unallocated memory, never write over the end of arrays,
1056 always check values read from some untrusted source before using them
1057 as array index or other risky things.
1058@item
1059 Remember to check if you need to bump versions for the specific libav
1060 parts (libavutil, libavcodec, libavformat) you are changing. You need
b98052d5 1061 to change the version integer.
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1062 Incrementing the first component means no backward compatibility to
1063 previous versions (e.g. removal of a function from the public API).
1064 Incrementing the second component means backward compatible change
b98052d5
PR
1065 (e.g. addition of a function to the public API or extension of an
1066 existing data structure).
d0e1cd3d
DB
1067 Incrementing the third component means a noteworthy binary compatible
1068 change (e.g. encoder bug fix that matters for the decoder).
1069@item
53407b64 1070 Compiler warnings indicate potential bugs or code with bad style. If a type of
9908c1a8
DB
1071 warning always points to correct and clean code, that warning should
1072 be disabled, not the code changed.
1073 Thus the remaining warnings can either be bugs or correct code.
beaa4a91 1074 If it is a bug, the bug has to be fixed. If it is not, the code should
9908c1a8
DB
1075 be changed to not generate a warning unless that causes a slowdown
1076 or obfuscates the code.
d0e1cd3d
DB
1077@item
1078 If you add a new file, give it a proper license header. Do not copy and
1079 paste it from a random place, use an existing file as template.
1080@end enumerate
1081
1082We think our rules are not too hard. If you have comments, contact us.
1083
1084Note, these rules are mostly borrowed from the MPlayer project.
1085
1086@section Submitting patches
1087
1088First, (@pxref{Coding Rules}) above if you did not yet.
1089
1090When you submit your patch, try to send a unified diff (diff '-up'
1091option). We cannot read other diffs :-)
1092
1093Also please do not submit a patch which contains several unrelated changes.
1094Split it into separate, self-contained pieces. This does not mean splitting
1095file by file. Instead, make the patch as small as possible while still
1096keeping it as a logical unit that contains an individual change, even
1097if it spans multiple files. This makes reviewing your patches much easier
1098for us and greatly increases your chances of getting your patch applied.
1099
1100Run the regression tests before submitting a patch so that you can
1101verify that there are no big problems.
1102
1103Patches should be posted as base64 encoded attachments (or any other
1104encoding which ensures that the patch will not be trashed during
1105transmission) to the ffmpeg-devel mailing list, see
1106@url{http://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel}
1107
1108It also helps quite a bit if you tell us what the patch does (for example
1109'replaces lrint by lrintf'), and why (for example '*BSD isn't C99 compliant
1110and has no lrint()')
1111
1112Also please if you send several patches, send each patch as a separate mail,
1113do not attach several unrelated patches to the same mail.
1114
28ce1839
RP
1115@section New codecs or formats checklist
1116
1117@enumerate
1118@item
1119 Did you use av_cold for codec initialization and close functions?
1120@item
1121 Did you add a long_name under NULL_IF_CONFIG_SMALL to the AVCodec or
1122 AVInputFormat/AVOutputFormat struct?
1123@item
1124 Did you bump the minor version number in @file{avcodec.h} or
1125 @file{avformat.h}?
1126@item
1127 Did you register it in @file{allcodecs.c} or @file{allformats.c}?
1128@item
1129 Did you add the CodecID to @file{avcodec.h}?
1130@item
1131 If it has a fourcc, did you add it to @file{libavformat/riff.c},
1132 even if it is only a decoder?
1133@item
1134 Did you add a rule to compile the appropriate files in the Makefile?
1135 Remember to do this even if you're just adding a format to a file that is
1136 already being compiled by some other rule, like a raw demuxer.
1137@item
1138 Did you add an entry to the table of supported formats or codecs in the
1139 documentation?
1140@item
1141 Did you add an entry in the Changelog?
1142@item
1143 If it depends on a parser or a library, did you add that dependency in
1144 configure?
1145@item
1146 Did you "svn add" the appropriate files before commiting?
1147@end enumerate
1148
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1149@section patch submission checklist
1150
1151@enumerate
1152@item
1153 Do the regression tests pass with the patch applied?
1154@item
2cdba8bf
DB
1155 Does @code{make checkheaders} pass with the patch applied?
1156@item
d0e1cd3d
DB
1157 Is the patch a unified diff?
1158@item
1159 Is the patch against latest FFmpeg SVN?
1160@item
1161 Are you subscribed to ffmpeg-dev?
1162 (the list is subscribers only due to spam)
1163@item
1164 Have you checked that the changes are minimal, so that the same cannot be
1165 achieved with a smaller patch and/or simpler final code?
1166@item
1167 If the change is to speed critical code, did you benchmark it?
1168@item
1169 If you did any benchmarks, did you provide them in the mail?
1170@item
1171 Have you checked that the patch does not introduce buffer overflows or
1172 other security issues?
1173@item
63d247ea
DB
1174 Did you test your decoder or demuxer against damaged data? If no, see
1175 tools/trasher and the noise bitstream filter. Your decoder or demuxer
1176 should not crash or end in a (near) infinite loop when fed damaged data.
b885e0db 1177@item
d0e1cd3d
DB
1178 Is the patch created from the root of the source tree, so it can be
1179 applied with @code{patch -p0}?
1180@item
1181 Does the patch not mix functional and cosmetic changes?
1182@item
1183 Did you add tabs or trailing whitespace to the code? Both are forbidden.
1184@item
1185 Is the patch attached to the email you send?
1186@item
1187 Is the mime type of the patch correct? It should be text/x-diff or
1188 text/x-patch or at least text/plain and not application/octet-stream.
1189@item
1190 If the patch fixes a bug, did you provide a verbose analysis of the bug?
1191@item
1192 If the patch fixes a bug, did you provide enough information, including
1193 a sample, so the bug can be reproduced and the fix can be verified?
1194 Note please do not attach samples >100k to mails but rather provide a
0fa5f24c 1195 URL, you can upload to ftp://upload.ffmpeg.org
d0e1cd3d
DB
1196@item
1197 Did you provide a verbose summary about what the patch does change?
1198@item
1199 Did you provide a verbose explanation why it changes things like it does?
1200@item
1201 Did you provide a verbose summary of the user visible advantages and
1202 disadvantages if the patch is applied?
1203@item
1204 Did you provide an example so we can verify the new feature added by the
1205 patch easily?
1206@item
1207 If you added a new file, did you insert a license header? It should be
1208 taken from FFmpeg, not randomly copied and pasted from somewhere else.
1209@item
1210 You should maintain alphabetical order in alphabetically ordered lists as
1211 long as doing so does not break API/ABI compatibility.
1212@item
1213 Lines with similar content should be aligned vertically when doing so
1214 improves readability.
1215@item
1216 Did you provide a suggestion for a clear commit log message?
1217@end enumerate
1218
1219@section Patch review process
1220
1221All patches posted to ffmpeg-devel will be reviewed, unless they contain a
1222clear note that the patch is not for SVN.
1223Reviews and comments will be posted as replies to the patch on the
1224mailing list. The patch submitter then has to take care of every comment,
1225that can be by resubmitting a changed patch or by discussion. Resubmitted
1226patches will themselves be reviewed like any other patch. If at some point
1227a patch passes review with no comments then it is approved, that can for
1228simple and small patches happen immediately while large patches will generally
1229have to be changed and reviewed many times before they are approved.
1230After a patch is approved it will be committed to the repository.
1231
1232We will review all submitted patches, but sometimes we are quite busy so
1233especially for large patches this can take several weeks.
1234
1235When resubmitting patches, please do not make any significant changes
1236not related to the comments received during review. Such patches will
1237be rejected. Instead, submit significant changes or new features as
1238separate patches.
1239
1240@section Regression tests
1241
1242Before submitting a patch (or committing to the repository), you should at least
1243test that you did not break anything.
1244
1245The regression tests build a synthetic video stream and a synthetic
1246audio stream. These are then encoded and decoded with all codecs or
1247formats. The CRC (or MD5) of each generated file is recorded in a
1248result file. A 'diff' is launched to compare the reference results and
1249the result file.
1250
1251The regression tests then go on to test the FFserver code with a
1252limited set of streams. It is important that this step runs correctly
1253as well.
1254
1255Run 'make test' to test all the codecs and formats.
1256
1257Run 'make fulltest' to test all the codecs, formats and FFserver.
1258
1259[Of course, some patches may change the results of the regression tests. In
1260this case, the reference results of the regression tests shall be modified
1261accordingly].
1262
1263@bye