Add some more missing codecs and update names to match the codec long_name.
[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
dd2d651d 84@item Flash Video (FLV) @tab @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.
dd2d651d 93@item id Quake II CIN video @tab @tab X
76ec3939 94@item id RoQ @tab X @tab X
d698c5d3 95 @tab Used in Quake III, Jedi Knight 2, other computer games.
c6b2dc34 96@item IFF @tab @tab X
d698c5d3 97 @tab Interchange File Format
c6b2dc34 98@item Interplay MVE @tab @tab X
d698c5d3 99 @tab Format used in various Interplay computer games.
c6b2dc34 100@item LMLM4 @tab @tab X
d698c5d3 101 @tab Used by Linux Media Labs MPEG-4 PCI boards
64c2f20a 102@item Matroska @tab X @tab X
39271be4 103@item Matroska audio @tab X @tab
913c3e2c 104@item MAXIS XA @tab @tab X
d698c5d3 105 @tab Used in Sim City 3000; file extension .xa.
64c2f20a 106@item Monkey's Audio @tab @tab X
822cc8f7 107@item Motion Pixels MVI @tab @tab X
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108@item MOV/QuickTime/MP4 @tab X @tab X
109 @tab 3GP, 3GP2, PSP, iPod variants supported
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110@item MP2 @tab X @tab X
111@item MP3 @tab X @tab X
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112@item MPEG-1 System @tab X @tab X
113 @tab muxed audio and video, VCD format supported
114@item MPEG-PS (program stream) @tab X @tab X
115 @tab also known as @code{VOB} file, SVCD and DVD format supported
116@item MPEG-TS (transport stream) @tab X @tab X
d698c5d3 117 @tab also known as DVB Transport Stream
c6b2dc34 118@item MPEG-4 @tab X @tab X
d698c5d3 119 @tab MPEG-4 is a variant of QuickTime.
39271be4 120@item MIME multipart JPEG @tab X @tab
bac4c85c 121@item MSN TCP webcam @tab @tab X
d698c5d3 122 @tab Used by MSN Messenger webcam streams.
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123@item MTV @tab @tab X
124@item Musepack @tab @tab X
125@item Musepack SV8 @tab @tab X
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126@item Material eXchange Format (MXF) @tab X @tab X
127 @tab SMPTE 377M, used by D-Cinema, broadcast industry.
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128@item Material eXchange Format (MXF), D-10 Mapping @tab X @tab X
129 @tab SMPTE 386M, D-10/IMX Mapping.
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130@item NC camera feed @tab @tab X
131 @tab NC (AVIP NC4600) camera streams
132@item Nullsoft Streaming Video @tab @tab X
39271be4 133@item NuppelVideo @tab @tab X
c6b2dc34 134@item NUT @tab X @tab X
d698c5d3 135 @tab NUT Open Container Format
39271be4 136@item Ogg @tab X @tab X
913c3e2c 137@item TechnoTrend PVA @tab @tab X
d698c5d3 138 @tab Used by TechnoTrend DVB PCI boards.
43dedc1e 139@item raw ADTS (AAC) @tab X @tab X
76ec3939 140@item raw AC-3 @tab X @tab X
adc5abf7 141@item raw Chinese AVS video @tab @tab X
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142@item raw CRI ADX @tab X @tab X
143@item raw Dirac @tab X @tab X
144@item raw DNxHD @tab X @tab X
145@item raw DTS @tab X @tab X
146@item raw E-AC-3 @tab X @tab X
147@item raw FLAC @tab X @tab X
148@item raw GSM @tab @tab X
149@item raw H.261 @tab X @tab X
150@item raw H.263 @tab X @tab X
151@item raw H.264 @tab X @tab X
152@item raw Ingenient MJPEG @tab @tab X
76ec3939 153@item raw MJPEG @tab X @tab X
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154@item raw MLP @tab @tab X
155@item raw MPEG @tab @tab X
156@item raw MPEG-1 @tab @tab X
157@item raw MPEG-2 @tab @tab X
158@item raw MPEG-4 @tab X @tab X
159@item raw NULL @tab X @tab
81b55ee5 160@item raw video @tab X @tab X
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161@item raw id RoQ @tab X @tab
162@item raw Shorten @tab @tab X
163@item raw VC-1 @tab @tab X
164@item raw PCM A-law @tab X @tab X
165@item raw PCM mu-law @tab X @tab X
166@item raw PCM signed 8 bit @tab X @tab X
167@item raw PCM signed 16 bit big-endian @tab X @tab X
168@item raw PCM signed 16 bit little-endian @tab X @tab X
169@item raw PCM signed 24 bit big-endian @tab X @tab X
170@item raw PCM signed 24 bit little-endian @tab X @tab X
171@item raw PCM signed 32 bit big-endian @tab X @tab X
172@item raw PCM signed 32 bit little-endian @tab X @tab X
173@item raw PCM unsigned 8 bit @tab X @tab X
174@item raw PCM unsigned 16 bit big-endian @tab X @tab X
175@item raw PCM unsigned 16 bit little-endian @tab X @tab X
176@item raw PCM unsigned 24 bit big-endian @tab X @tab X
177@item raw PCM unsigned 24 bit little-endian @tab X @tab X
178@item raw PCM unsigned 32 bit big-endian @tab X @tab X
179@item raw PCM unsigned 32 bit little-endian @tab X @tab X
180@item raw PCM floating-point 32 bit big-endian @tab X @tab X
181@item raw PCM floating-point 32 bit little-endian @tab X @tab X
182@item raw PCM floating-point 64 bit big-endian @tab X @tab X
183@item raw PCM floating-point 64 bit little-endian @tab X @tab X
39271be4 184@item RDT @tab @tab X
913c3e2c 185@item REDCODE R3D @tab @tab X
7eb68edb 186 @tab File format used by RED Digital cameras, contains JPEG 2000 frames and PCM audio.
64c2f20a 187@item RealMedia @tab X @tab X
39271be4 188@item Redirector @tab @tab X
913c3e2c 189@item Renderware TeXture Dictionary @tab @tab X
c6b2dc34 190@item RL2 @tab @tab X
d698c5d3 191 @tab Audio and video format used in some games by Entertainment Software Partners.
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192@item RPL/ARMovie @tab @tab X
193@item RTP @tab @tab X
194@item RTSP @tab @tab X
195@item SDP @tab @tab X
c6b2dc34 196@item Sega FILM/CPK @tab @tab X
d698c5d3 197 @tab Used in many Sega Saturn console games.
913c3e2c 198@item Sierra SOL @tab @tab X
d698c5d3 199 @tab .sol files used in Sierra Online games.
c6b2dc34 200@item Sierra VMD @tab @tab X
d698c5d3 201 @tab Used in Sierra CD-ROM games.
c6b2dc34 202@item Smacker @tab @tab X
d698c5d3 203 @tab Multimedia format used by many games.
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204@item Sony OpenMG (OMA) @tab @tab X
205 @tab Audio format used in Sony Sonic Stage and Sony Vegas.
206@item Sony PlayStation STR @tab @tab X
64c2f20a 207@item SUN AU format @tab X @tab X
c6b2dc34 208@item THP @tab @tab X
d698c5d3 209 @tab Used on the Nintendo GameCube.
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210@item Tiertex Limited SEQ @tab @tab X
211 @tab Tiertex .seq files used in the DOS CD-ROM version of the game Flashback.
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212@item True Audio @tab @tab X
213@item VC-1 test bitstream @tab X @tab X
c6b2dc34 214@item WAV @tab X @tab X
39271be4 215@item WavPack @tab @tab X
913c3e2c 216@item Wing Commander III movie @tab @tab X
d698c5d3 217 @tab Multimedia format used in Origin's Wing Commander III computer game.
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218@item Westwood Studios audio @tab @tab X
219 @tab Multimedia format used in Westwood Studios games.
220@item Westwood Studios VQA @tab @tab X
221 @tab Multimedia format used in Westwood Studios games.
39271be4 222@item YUV4MPEG pipe @tab X @tab X
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223@end multitable
224
225@code{X} means that encoding (resp. decoding) is supported.
226
227@section Image Formats
228
229FFmpeg can read and write images for each frame of a video sequence. The
230following image formats are supported:
231
232@multitable @columnfractions .4 .1 .1 .4
b3de4544 233@item Name @tab Encoding @tab Decoding @tab Comments
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234@item .Y.U.V @tab X @tab X
235 @tab one raw file per component
236@item animated GIF @tab X @tab X
237 @tab Only uncompressed GIFs are generated.
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238@item BMP @tab X @tab X
239 @tab Microsoft BMP image
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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
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244@item JPEG-LS @tab X @tab X
245@item LJPEG @tab X @tab
246 @tab Lossless JPEG
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247@item PAM @tab X @tab X
248 @tab PAM is a PNM extension with alpha support.
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249@item PBM @tab X @tab X
250 @tab Portable BitMap image
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251@item PCX @tab @tab X
252 @tab PC Paintbrush
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253@item PGM @tab X @tab X
254 @tab Portable GrayMap image
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255@item PGMYUV @tab X @tab X
256 @tab PGM with U and V components in YUV 4:2:0
257@item PNG @tab X @tab X
258 @tab 2/4 bpp not supported yet
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259@item PPM @tab X @tab X
260 @tab Portable PixelMap image
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261@item PTX @tab @tab X
262 @tab V.Flash PTX format
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263@item SGI @tab X @tab X
264 @tab SGI RGB image format
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265@item Sun Rasterfile @tab @tab X
266 @tab Sun RAS image format
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267@item TIFF @tab X @tab X
268 @tab YUV, JPEG and some extension is not supported yet.
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269@item Truevision Targa @tab X @tab X
270 @tab Targa (.TGA) image format
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271@end multitable
272
273@code{X} means that encoding (resp. decoding) is supported.
274
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275@code{E} means that support is provided through an external library.
276
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277@section Video Codecs
278
279@multitable @columnfractions .4 .1 .1 .4
b3de4544 280@item Name @tab Encoding @tab Decoding @tab Comments
9510f59a 281@item 4X Movie @tab @tab X
d698c5d3 282 @tab Used in certain computer games.
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283@item 8SVX exponential @tab @tab X
284@item 8SVX fibonacci @tab @tab X
913c3e2c 285@item American Laser Games MM @tab @tab X
d698c5d3 286 @tab Used in games like Mad Dog McCree.
a1c5b6ec 287@item AMV Video @tab @tab X
d698c5d3 288 @tab Used in Chinese MP3 players.
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289@item Apple MJPEG-B @tab @tab X
290@item Apple QuickDraw @tab @tab X
d698c5d3 291 @tab fourcc: qdrw
d66d8b83 292@item Asus v1 @tab X @tab X
d698c5d3 293 @tab fourcc: ASV1
d66d8b83 294@item Asus v2 @tab X @tab X
d698c5d3 295 @tab fourcc: ASV2
d66d8b83 296@item ATI VCR1 @tab @tab X
d698c5d3 297 @tab fourcc: VCR1
d66d8b83 298@item ATI VCR2 @tab @tab X
d698c5d3 299 @tab fourcc: VCR2
dd2d651d 300@item Autodesk Animator Flic video @tab @tab X
d66d8b83 301@item Autodesk RLE @tab @tab X
d698c5d3 302 @tab fourcc: AASC
9510f59a 303@item AVS (Audio Video Standard) video @tab @tab X
d698c5d3 304 @tab Video encoding used by the Creature Shock game.
68dddf53 305@item Beam Software VB @tab @tab X
9510f59a 306@item Bethesda VID video @tab @tab X
d698c5d3 307 @tab Used in some games from Bethesda Softworks.
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308@item Brute Force & Ignorance @tab @tab X
309 @tab Used in the game Flash Traffic: City of Angels.
bac4c85c 310@item C93 video @tab @tab X
d698c5d3 311 @tab Codec used in Cyberia game.
d66d8b83 312@item CamStudio @tab @tab X
d698c5d3 313 @tab fourcc: CSCD
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314@item Chinese AVS video @tab @tab X
315 @tab AVS1-P2, JiZhun profile
316@item Delphine Software International CIN video @tab @tab X
317 @tab Codec used in Delphine Software International games.
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318@item Cinepak @tab @tab X
319@item Cirrus Logic AccuPak @tab @tab X
d698c5d3 320 @tab fourcc: CLJR
9510f59a 321@item Creative YUV (CYUV) @tab @tab X
82ced5a9 322@item Dirac @tab E @tab E
360f980b 323 @tab supported through external libdirac/libschroedinger libraries
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324@item DNxHD @tab X @tab X
325 @tab aka SMPTE VC3
68dddf53 326@item Duck TrueMotion 1.0 @tab @tab X
d698c5d3 327 @tab fourcc: DUCK
68dddf53 328@item Duck TrueMotion 2.0 @tab @tab X
d698c5d3 329 @tab fourcc: TM20
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330@item DV (Digital Video) @tab X @tab X
331@item Feeble Files/ScummVM DXA @tab @tab X
d698c5d3 332 @tab Codec originally used in Feeble Files game.
9510f59a 333@item Electronic Arts CMV video @tab @tab X
d698c5d3 334 @tab Used in NHL 95 game.
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335@item Electronic Arts TGV video @tab @tab X
336@item Electronic Arts TGQ video @tab @tab X
337@item Electronic Arts TQI video @tab @tab X
338@item Escape 124 @tab @tab X
339@item FFmpeg codec #1 @tab X @tab X
d698c5d3 340 @tab experimental lossless codec (fourcc: FFV1)
dd2d651d 341@item Flash Screen Video v1 @tab X @tab X
d698c5d3 342 @tab fourcc: FSV1
dd2d651d 343@item Flash Video (FLV) @tab X @tab X
d698c5d3 344 @tab Sorenson H.263 used in Flash
dd2d651d 345@item Fraps @tab @tab X
d66d8b83 346@item H.261 @tab X @tab X
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347@item H.263 / H.263-1996 @tab X @tab X
348@item H.263+ / H.263-1998 / H.263 version 2 @tab X @tab X
349@item H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10 @tab E @tab X
360f980b 350 @tab encoding supported through external library libx264
dd2d651d 351@item H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10 (VDPAU acceleration) @tab E @tab X
d66d8b83 352@item HuffYUV @tab X @tab X
dd2d651d 353@item HuffYUV FFmpeg variant @tab X @tab X
d66d8b83 354@item IBM Ultimotion @tab @tab X
d698c5d3 355 @tab fourcc: ULTI
bac4c85c 356@item id Cinematic video @tab @tab X
d698c5d3 357 @tab Used in Quake II.
a1c5b6ec 358@item id RoQ video @tab X @tab X
d698c5d3 359 @tab Used in Quake III, Jedi Knight 2, other computer games.
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360@item Intel H.263 @tab @tab X
361@item Intel Indeo 2 @tab @tab X
d66d8b83 362@item Intel Indeo 3 @tab @tab X
dd2d651d 363@item Interplay C93 @tab @tab X
9510f59a 364 @tab Used in the game Cyberia from Interplay.
dd2d651d 365@item Interplay MVE video @tab @tab X
d698c5d3 366 @tab Used in Interplay .MVE files.
dd2d651d 367@item Karl Morton's video codec @tab @tab X
d698c5d3 368 @tab Codec used in Worms games.
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369@item LCL (LossLess Codec Library) MSZH @tab @tab X
370@item LCL (LossLess Codec Library) ZLIB @tab E @tab E
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371@item LOCO @tab @tab X
372@item lossless MJPEG @tab X @tab X
373@item Microsoft RLE @tab @tab X
dd2d651d 374@item Microsoft Video 1 @tab @tab X
d66d8b83 375@item Mimic @tab @tab X
d698c5d3 376 @tab Used in MSN Messenger Webcam streams.
d66d8b83 377@item Miro VideoXL @tab @tab X
d698c5d3 378 @tab fourcc: VIXL
eacf8613 379@item MJPEG (Motion JPEG) @tab X @tab X
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380@item Motion Pixels video @tab @tab X
381@item MPEG-1 video @tab X @tab X
382@item MPEG-1/2 video XvMC (X-Video Motion Compensation) @tab @tab X
383@item MPEG-1/2 video (VDPAU acceleration) @tab @tab X
384@item MPEG-2 video @tab X @tab X
385@item MPEG-4 part 2 @tab X @tab X
386 @ libxvidcore can be used alternatively for encoding.
387@item MPEG-4 part 2 Microsoft variant version 1 @tab X @tab X
388@item MPEG-4 part 2 Microsoft variant version 2 @tab X @tab X
389@item MPEG-4 part 2 Microsoft variant version 3 @tab X @tab X
eacf8613 390@item Nintendo Gamecube THP video @tab @tab X
d66d8b83 391@item On2 VP3 @tab @tab X
d698c5d3 392 @tab still experimental
d66d8b83 393@item On2 VP5 @tab @tab X
d698c5d3 394 @tab fourcc: VP50
d66d8b83 395@item On2 VP6 @tab @tab X
d698c5d3 396 @tab fourcc: VP60,VP61,VP62
d66d8b83 397@item planar RGB @tab @tab X
d698c5d3 398 @tab fourcc: 8BPS
a1c5b6ec 399@item Q-team QPEG @tab @tab X
d698c5d3 400 @tab fourccs: QPEG, Q1.0, Q1.1
9510f59a 401@item QuickTime 8BPS video @tab @tab X
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402@item QuickTime Animation (RLE) video @tab X @tab X
403 @tab fourcc: 'rle '
404@item QuickTime Graphics (SMC) @tab @tab X
405 @tab fourcc: 'smc '
406@item QuickTime video (RPZA) @tab @tab X
407 @tab fourcc: rpza
408@item Raw Video @tab X @tab X
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409@item RealVideo 1.0 @tab X @tab X
410@item RealVideo 2.0 @tab X @tab X
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411@item RealVideo 3.0 @tab @tab X
412 @tab still far from ideal
11c0f9ec 413@item RealVideo 4.0 @tab @tab X
68dddf53 414@item Renderware TXD (TeXture Dictionary) @tab @tab X
d698c5d3 415 @tab Texture dictionaries used by the Renderware Engine.
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416@item RL2 video @tab @tab X
417 @tab used in some games by Entertainment Software Partners
d66d8b83 418@item RTjpeg @tab @tab X
d698c5d3 419 @tab Video encoding used in NuppelVideo files.
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420@item Sierra VMD video @tab @tab X
421 @tab Used in Sierra VMD files.
bac4c85c 422@item Smacker video @tab @tab X
d698c5d3 423 @tab Video encoding used in Smacker.
68dddf53 424@item SMPTE VC-1 @tab @tab X
d66d8b83 425@item Snow @tab X @tab X
d698c5d3 426 @tab experimental wavelet codec (fourcc: SNOW)
eacf8613 427@item Sony PlayStation MDEC (Motion DECoder) @tab @tab X
a1c5b6ec 428@item Sorenson Vector Quantizer 1 @tab X @tab X
d698c5d3 429 @tab fourcc: SVQ1
a1c5b6ec 430@item Sorenson Vector Quantizer 3 @tab @tab X
d698c5d3 431 @tab fourcc: SVQ3
a1c5b6ec 432@item Sunplus JPEG (SP5X) @tab @tab X
d698c5d3 433 @tab fourcc: SP5X
68dddf53 434@item TechSmith Screen Capture Codec @tab @tab X
d698c5d3 435 @tab fourcc: TSCC
82ced5a9 436@item Theora @tab E @tab X
360f980b 437 @tab encoding supported through external library libtheora
a1c5b6ec 438@item Tiertex Limited SEQ video @tab @tab X
d698c5d3 439 @tab Codec used in DOS CD-ROM FlashBack game.
eacf8613 440@item VMware Screen Codec / VMware Video @tab @tab X
d698c5d3 441 @tab Codec used in videos captured by VMware.
eacf8613 442@item Westwood Studios VQA (Vector Quantized Animation) video @tab @tab X
dd2d651d 443@item Windows Media Video 7 @tab X @tab X
eacf8613 444@item Windows Media Video 8 @tab X @tab X
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445@item Windows Media Video 9 @tab @tab X
446 @tab not completely working
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447@item Wing Commander III / Xan @tab @tab X
448 @tab Used in Wing Commander III .MVE files.
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449@item Winnov WNV1 @tab @tab X
450@item WMV7 @tab X @tab X
39271be4 451@item YAMAHA SMAF @tab X @tab X
d66d8b83 452@item ZLIB @tab X @tab X
d698c5d3 453 @tab part of LCL, encoder experimental
eacf8613 454@item Zip Motion Blocks Video @tab X @tab X
d698c5d3 455 @tab Encoder works only in PAL8.
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456@end multitable
457
458@code{X} means that encoding (resp. decoding) is supported.
459
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460@code{E} means that support is provided through an external library.
461
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462@section Audio Codecs
463
485ec4f1 464@multitable @columnfractions .4 .1 .1 .4
b3de4544 465@item Name @tab Encoding @tab Decoding @tab Comments
9510f59a 466@item 4X Movie ADPCM @tab @tab X
16d81b27 467@item 8SVX audio @tab @tab X
82ced5a9 468@item AAC @tab E @tab X
360f980b 469 @tab encoding supported through external library libfaac
270fc177 470@item AC-3 @tab X @tab X
82ced5a9 471@item AMR-NB @tab E @tab E
360f980b 472 @tab supported through external library libamrnb
82ced5a9 473@item AMR-WB @tab E @tab E
360f980b 474 @tab supported through external library libamrwb
833e90dd 475@item Apple lossless audio @tab X @tab X
d698c5d3 476 @tab QuickTime fourcc 'alac'
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477@item Atrac 3 @tab @tab X
478@item CDROM XA ADPCM @tab @tab X
479@item Delphine Software International CIN audio @tab @tab X
d698c5d3 480 @tab Codec used in Delphine Software International games.
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481@item COOK @tab @tab X
482 @tab All versions except 5.1 are supported.
483@item Creative Technology ADPCM @tab @tab X
d698c5d3 484 @tab 16 -> 4, 8 -> 4, 8 -> 3, 8 -> 2
9510f59a 485@item DCA (DTS Coherent Acoustics) @tab @tab X
16d81b27 486@item DSP Group TrueSpeech @tab @tab X
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487@item DV audio @tab @tab X
488@item Electronic Arts ADPCM @tab @tab X
d698c5d3 489 @tab Used in various EA titles.
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490@item Electronic Arts Maxis CDROM XS ADPCM @tab @tab X
491 @tab Used in Sim City 3000.
492@item Electronic Arts R1 ADPCM @tab @tab X
493@item Electronic Arts R2 ADPCM @tab @tab X
494@item Electronic Arts R3 ADPCM @tab @tab X
495@item Electronic Arts XAS ADPCM @tab @tab X
44723c84 496@item Enhanced AC-3 @tab @tab X
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497@item FLAC (Free Lossless Audio Codec) @tab X @tab IX
498@item G.726 ADPCM @tab X @tab X
499@item G.729 @tab @tab X
82ced5a9 500@item GSM @tab E @tab E
3f33271a 501 @tab supported through external library libgsm
dd2d651d 502@item GSM Microsoft variant @tab E @tab E
3f33271a 503 @tab supported through external library libgsm
16d81b27 504@item id RoQ DPCM @tab X @tab X
d698c5d3 505 @tab Used in Quake III, Jedi Knight 2, other computer games.
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506@item IMA AMV ADPCM @tab @tab X
507 @tab Used in AMV files
508@item IMA Electronic Arts EACS ADPCM @tab @tab X
509@item IMA Electronic Arts SEAD ADPCM @tab @tab X
510@item IMA Funcom ADPCM @tab @tab X
511@item IMA QuickTime ADPCM @tab X @tab X
512@item IMA Loki SDL MJPEG ADPCM @tab @tab X
513@item IMA WAV ADPCM @tab X @tab X
514@item IMA Westwood ADPCM @tab @tab X
dd2d651d 515@item IMC (Intel Music Coder) @tab @tab X
9510f59a 516@item Interplay DPCM @tab @tab X
d698c5d3 517 @tab Used in various Interplay computer games.
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518@item ISS IMA ADPCM @tab @tab X
519 @tab Used in FunCom games.
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520@item IMA Duck DK3 ADPCM @tab @tab X
521 @tab Used in some Sega Saturn console games.
522@item IMA Duck DK4 ADPCM @tab @tab X
523 @tab Used in some Sega Saturn console games.
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524@item MACE (Macintosh Audio Compression/Expansion) 3:1 @tab @tab X
525@item MACE (Macintosh Audio Compression/Expansion) 6:1 @tab @tab X
16d81b27 526@item Microsoft ADPCM @tab X @tab X
dd2d651d 527@item MLP(Meridian Lossless Packing)/TrueHD @tab @tab X
d698c5d3 528 @tab Used in DVD-Audio and Blu-Ray discs.
16d81b27 529@item Monkey's Audio @tab @tab X
d698c5d3 530 @tab Only versions 3.97-3.99 are supported.
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531@item MP1 (MPEG audio layer 1) @tab @tab IX
532@item MP2 (MPEG audio layer 2) @tab IX @tab IX
533@item MP3 (MPEG audio layer 3) @tab E @tab IX
534 @tab encoding supported through external library LAME, ADU MP3 and MP3onMP4 also supported
16d81b27 535@item MS IMA ADPCM @tab X @tab X
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536@item Musepack SV7 @tab @tab X
537@item Musepack SV8 @tab @tab X
755ba886 538@item Nellymoser ASAO @tab X @tab X
9510f59a 539@item Nintendo Gamecube THP ADPCM @tab @tab X
73b458e3 540@item QCELP / PureVoice @tab @tab X
a1c5b6ec 541@item QDesign Music Codec 2 @tab @tab X
d698c5d3 542 @tab There are still some distortions.
16d81b27 543@item QT IMA ADPCM @tab X @tab X
a1c5b6ec 544@item RealAudio 1.0 (14.4K) @tab @tab X
d698c5d3 545 @tab Real 14400 bit/s codec
a1c5b6ec 546@item RealAudio 2.0 (28.8K) @tab @tab X
d698c5d3 547 @tab Real 28800 bit/s codec
a1c5b6ec 548@item RealAudio 3.0 (dnet) @tab IX @tab X
a692130f 549 @tab Real low bitrate AC-3 codec
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550@item SEGA CRI ADX ADPCM @tab X @tab X
551 @tab Used in Sega Dreamcast games.
552@item Shockwave Flash ADPCM @tab X @tab X
bac4c85c 553@item Shorten @tab @tab X
16d81b27 554@item Sierra Online DPCM @tab @tab X
d698c5d3 555 @tab Used in Sierra Online game audio files.
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556@item Sierra VMD audio @tab @tab X
557 @tab Used in Sierra VMD files.
bac4c85c 558@item Smacker audio @tab @tab X
16d81b27 559@item SMJPEG IMA ADPCM @tab @tab X
d698c5d3 560 @tab Used in certain Loki game ports.
9510f59a 561@item Sol DPCM @tab @tab X
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562@item Sonic @tab X @tab X
563 @tab experimental codec
564@item Sonic lossless @tab X @tab X
565 @tab experimental codec
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566@item Sound Blaster Pro 2-bit ADPCM @tab @tab X
567@item Sound Blaster Pro 2.6-bit ADPCM @tab @tab X
568@item Sound Blaster Pro 4-bit ADPCM @tab @tab X
82ced5a9 569@item Speex @tab @tab E
360f980b 570 @tab supported through external library libspeex
16d81b27 571@item True Audio (TTA) @tab @tab X
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572@item Vorbis @tab E @tab X
573 @ A native but very primitive encoder exists.
bac4c85c 574@item WavPack @tab @tab X
16d81b27 575@item Westwood Studios IMA ADPCM @tab @tab X
d698c5d3 576 @tab Used in Westwood Studios games like Command and Conquer.
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577@item Westwood Audio (SND1) @tab @tab X
578@item Windows Media Audio 1 @tab X @tab X
579@item Windows Media Audio 2 @tab X @tab X
16d81b27 580@item Xan DPCM @tab @tab X
d698c5d3 581 @tab Used in Origin's Wing Commander IV AVI files.
9510f59a 582@item Yamaha ADPCM @tab X @tab X
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583@end multitable
584
585@code{X} means that encoding (resp. decoding) is supported.
586
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587@code{E} means that support is provided through an external library.
588
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589@code{I} means that an integer-only version is available, too (ensures high
590performance on systems without hardware floating point support).
591
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592@section Subtitle Formats
593
485ec4f1 594@multitable @columnfractions .4 .1 .1 .1 .1 .1
9afc2917 595@item Name @tab Muxing @tab Demuxing @tab Encoding @tab Decoding
913c3e2c 596@item SSA/ASS @tab X @tab X
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597@item DVB @tab X @tab X @tab X @tab X
598@item DVD @tab X @tab X @tab X @tab X
599@item XSUB @tab @tab @tab @tab X
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600@end multitable
601
602@code{X} means that the feature is supported.
603
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604@section Network Protocols
605
606@multitable @columnfractions .4 .1 .1 .1 .1 .1
607@item Name @tab Support
608@item file @tab X
609@item Gopher @tab X
610@item HTTP @tab X
611@item pipe @tab X
612@item RTP @tab X
613@item TCP @tab X
614@item UDP @tab X
615@end multitable
616
617@code{X} means that the protocol is supported.
618
619
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620@chapter Platform Specific information
621
622@section BSD
623
624BSD make will not build FFmpeg, you need to install and use GNU Make
625(@file{gmake}).
626
627@section Windows
628
46a845d0 629To get help and instructions for building FFmpeg under Windows, check out
d0e1cd3d 630the FFmpeg Windows Help Forum at
ab5ce4ae 631@url{http://ffmpeg.arrozcru.org/}.
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632
633@subsection Native Windows compilation
634
c1989552 635FFmpeg can be built to run natively on Windows using the MinGW tools. Install
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636the latest versions of MSYS and MinGW from @url{http://www.mingw.org/}.
637You can find detailed installation
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638instructions in the download section and the FAQ.
639
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640FFmpeg does not build out-of-the-box with the packages the automated MinGW
641installer provides. It also requires coreutils to be installed and many other
642packages updated to the latest version. The minimum version for some packages
643are listed below:
644
645@itemize
646@item bash 3.1
647@item msys-make 3.81-2 (note: not mingw32-make)
2014b51c 648@item w32api 3.13
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649@item mingw-runtime 3.15
650@end itemize
651
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652You will also need to pass @code{-fno-common} to the compiler to work around
653a GCC bug (see @url{http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37216}).
654
c1989552 655Within the MSYS shell, configure and make with:
d0e1cd3d 656
c1989552 657@example
0f898714 658./configure --enable-memalign-hack --extra-cflags=-fno-common
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659make
660make install
661@end example
d0e1cd3d 662
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663This will install @file{ffmpeg.exe} along with many other development files
664to @file{/usr/local}. You may specify another install path using the
665@code{--prefix} option in @file{configure}.
d0e1cd3d 666
c1989552 667Notes:
d0e1cd3d 668
c1989552 669@itemize
d0e1cd3d 670
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671@item In order to compile vhooks, you must have a POSIX-compliant libdl in
672your MinGW system. Get dlfcn-win32 from
673@url{http://code.google.com/p/dlfcn-win32}.
d0e1cd3d 674
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675@item In order to compile FFplay, you must have the MinGW development library
676of SDL. Get it from @url{http://www.libsdl.org}.
677Edit the @file{bin/sdl-config} script so that it points to the correct prefix
678where SDL was installed. Verify that @file{sdl-config} can be launched from
679the MSYS command line.
d0e1cd3d 680
d0e1cd3d 681@item By using @code{./configure --enable-shared} when configuring FFmpeg,
c1989552 682you can build libavutil, libavcodec and libavformat as DLLs.
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683
684@end itemize
685
c1989552 686@subsection Microsoft Visual C++ compatibility
d0e1cd3d 687
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688As stated in the FAQ, FFmpeg will not compile under MSVC++. However, if you
689want to use the libav* libraries in your own applications, you can still
690compile those applications using MSVC++. But the libav* libraries you link
691to @emph{must} be built with MinGW. However, you will not be able to debug
692inside the libav* libraries, since MSVC++ does not recognize the debug
693symbols generated by GCC.
694We strongly recommend you to move over from MSVC++ to MinGW tools.
d0e1cd3d 695
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696This description of how to use the FFmpeg libraries with MSVC++ is based on
697Microsoft Visual C++ 2005 Express Edition. If you have a different version,
698you might have to modify the procedures slightly.
d0e1cd3d 699
c1989552 700@subsubsection Using static libraries
d0e1cd3d 701
c1989552 702Assuming you have just built and installed FFmpeg in @file{/usr/local}.
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703
704@enumerate
705
706@item Create a new console application ("File / New / Project") and then
707select "Win32 Console Application". On the appropriate page of the
708Application Wizard, uncheck the "Precompiled headers" option.
709
710@item Write the source code for your application, or, for testing, just
711copy the code from an existing sample application into the source file
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712that MSVC++ has already created for you. For example, you can copy
713@file{output_example.c} from the FFmpeg distribution.
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714
715@item Open the "Project / Properties" dialog box. In the "Configuration"
716combo box, select "All Configurations" so that the changes you make will
717affect both debug and release builds. In the tree view on the left hand
718side, select "C/C++ / General", then edit the "Additional Include
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719Directories" setting to contain the path where the FFmpeg includes were
720installed (i.e. @file{c:\msys\1.0\local\include}).
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721Do not add MinGW's include directory here, or the include files will
722conflict with MSVC's.
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723
724@item Still in the "Project / Properties" dialog box, select
725"Linker / General" from the tree view and edit the
726"Additional Library Directories" setting to contain the @file{lib}
727directory where FFmpeg was installed (i.e. @file{c:\msys\1.0\local\lib}),
728the directory where MinGW libs are installed (i.e. @file{c:\mingw\lib}),
729and the directory where MinGW's GCC libs are installed
730(i.e. @file{C:\mingw\lib\gcc\mingw32\4.2.1-sjlj}). Then select
731"Linker / Input" from the tree view, and add the files @file{libavformat.a},
732@file{libavcodec.a}, @file{libavutil.a}, @file{libmingwex.a},
733@file{libgcc.a}, and any other libraries you used (i.e. @file{libz.a})
734to the end of "Additional Dependencies".
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735
736@item Now, select "C/C++ / Code Generation" from the tree view. Select
737"Debug" in the "Configuration" combo box. Make sure that "Runtime
738Library" is set to "Multi-threaded Debug DLL". Then, select "Release" in
739the "Configuration" combo box and make sure that "Runtime Library" is
740set to "Multi-threaded DLL".
741
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742@item Click "OK" to close the "Project / Properties" dialog box.
743
744@item MSVC++ lacks some C99 header files that are fundamental for FFmpeg.
745Get msinttypes from @url{http://code.google.com/p/msinttypes/downloads/list}
746and install it in MSVC++'s include directory
747(i.e. @file{C:\Program Files\Microsoft Visual Studio 8\VC\include}).
748
749@item MSVC++ also does not understand the @code{inline} keyword used by
750FFmpeg, so you must add this line before @code{#include}ing libav*:
751@example
752#define inline _inline
753@end example
754
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755@item Build your application, everything should work.
756
757@end enumerate
758
759@subsubsection Using shared libraries
760
761This is how to create DLL and LIB files that are compatible with MSVC++:
762
763@enumerate
764
765@item Add a call to @file{vcvars32.bat} (which sets up the environment
766variables for the Visual C++ tools) as the first line of @file{msys.bat}.
767The standard location for @file{vcvars32.bat} is
768@file{C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat},
769and the standard location for @file{msys.bat} is @file{C:\msys\1.0\msys.bat}.
770If this corresponds to your setup, add the following line as the first line
771of @file{msys.bat}:
772
773@example
774call "C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat"
775@end example
776
777Alternatively, you may start the @file{Visual Studio 2005 Command Prompt},
778and run @file{c:\msys\1.0\msys.bat} from there.
779
780@item Within the MSYS shell, run @code{lib.exe}. If you get a help message
781from @file{Microsoft (R) Library Manager}, this means your environment
782variables are set up correctly, the @file{Microsoft (R) Library Manager}
783is on the path and will be used by FFmpeg to create
784MSVC++-compatible import libraries.
785
786@item Build FFmpeg with
787
788@example
789./configure --enable-shared --enable-memalign-hack
790make
791make install
792@end example
793
794Your install path (@file{/usr/local/} by default) should now have the
795necessary DLL and LIB files under the @file{bin} directory.
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796
797@end enumerate
798
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799To use those files with MSVC++, do the same as you would do with
800the static libraries, as described above. But in Step 4,
801you should only need to add the directory where the LIB files are installed
802(i.e. @file{c:\msys\usr\local\bin}). This is not a typo, the LIB files are
803installed in the @file{bin} directory. And instead of adding @file{libxx.a}
804files, you should add @file{avcodec.lib}, @file{avformat.lib}, and
805@file{avutil.lib}. There should be no need for @file{libmingwex.a},
806@file{libgcc.a}, and @file{wsock32.lib}, nor any other external library
807statically linked into the DLLs. The @file{bin} directory contains a bunch
808of DLL files, but the ones that are actually used to run your application
809are the ones with a major version number in their filenames
810(i.e. @file{avcodec-51.dll}).
811
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812@subsection Cross compilation for Windows with Linux
813
814You must use the MinGW cross compilation tools available at
815@url{http://www.mingw.org/}.
816
817Then configure FFmpeg with the following options:
818@example
819./configure --target-os=mingw32 --cross-prefix=i386-mingw32msvc-
820@end example
821(you can change the cross-prefix according to the prefix chosen for the
822MinGW tools).
823
824Then you can easily test FFmpeg with Wine
825(@url{http://www.winehq.com/}).
826
827@subsection Compilation under Cygwin
828
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829The main issue with the 1.5.x Cygwin versions is that newlib, its C library,
830does not contain llrint(). You need to upgrade to the unstable 1.7.x versions,
831or leverage the implementation in MinGW (as explained below).
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832
833Just install your Cygwin with all the "Base" packages, plus the
834following "Devel" ones:
835@example
f496ab12 836binutils, gcc-core, make, subversion, mingw-runtime, diffutils
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837@end example
838
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839The experimental gcc4 package is still buggy, hence please
840use the official gcc 3.4.4 or a 4.2.x compiled from source by yourself.
841
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842Install the current binutils-20080624-2 as they work fine (the old
843binutils-20060709-1 proved buggy on shared builds).
d0e1cd3d 844
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845Then create a small library that just contains llrint():
846
847@example
848ar x /usr/lib/mingw/libmingwex.a llrint.o
849ar cq /usr/local/lib/libllrint.a llrint.o
850@end example
851
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852Then run
853
854@example
29c3d42b 855./configure --enable-static --disable-shared --extra-ldflags='-L /usr/local/lib' --extra-libs='-l llrint'
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856@end example
857
858to make a static build or
859
860@example
29c3d42b 861./configure --enable-shared --disable-static --extra-ldflags='-L /usr/local/lib' --extra-libs='-l llrint'
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862@end example
863
864to build shared libraries.
865
866If you want to build FFmpeg with additional libraries, download Cygwin
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867"Devel" packages for Ogg and Vorbis from any Cygwin packages repository:
868@example
869libogg-devel, libvorbis-devel
870@end example
871
872These library packages are only available from Cygwin Ports
be8497b0 873(@url{http://sourceware.org/cygwinports/}) :
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874
875@example
876yasm, libSDL-devel, libdirac-devel, libfaac-devel, libfaad-devel, libgsm-devel,
877libmp3lame-devel, libschroedinger1.0-devel, speex-devel, libtheora-devel,
878libxvidcore-devel
879@end example
880
881The recommendation for libnut and x264 is to build them from source by
882yourself, as they evolve too quickly for Cygwin Ports to be up to date.
d0e1cd3d 883
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884Cygwin 1.7.x has IPv6 support. You can add IPv6 to Cygwin 1.5.x by means
885of the @code{libgetaddrinfo-devel} package, available at Cygwin Ports.
886
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887@subsection Crosscompilation for Windows under Cygwin
888
889With Cygwin you can create Windows binaries that do not need the cygwin1.dll.
890
891Just install your Cygwin as explained before, plus these additional
892"Devel" packages:
893@example
894gcc-mingw-core, mingw-runtime, mingw-zlib
895@end example
896
897and add some special flags to your configure invocation.
898
899For a static build run
900@example
901./configure --target-os=mingw32 --enable-memalign-hack --enable-static --disable-shared --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
902@end example
903
904and for a build with shared libraries
905@example
906./configure --target-os=mingw32 --enable-memalign-hack --enable-shared --disable-static --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
907@end example
908
909@section BeOS
910
5f757b85 911BeOS support is broken in mysterious ways.
d0e1cd3d 912
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913@section OS/2
914
915For information about compiling FFmpeg on OS/2 see
916@url{http://www.edm2.com/index.php/FFmpeg}.
917
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918@chapter Developers Guide
919
920@section API
921@itemize @bullet
922@item libavcodec is the library containing the codecs (both encoding and
923decoding). Look at @file{libavcodec/apiexample.c} to see how to use it.
924
925@item libavformat is the library containing the file format handling (mux and
926demux code for several formats). Look at @file{ffplay.c} to use it in a
927player. See @file{output_example.c} to use it to generate audio or video
928streams.
929
930@end itemize
931
932@section Integrating libavcodec or libavformat in your program
933
934You can integrate all the source code of the libraries to link them
935statically to avoid any version problem. All you need is to provide a
936'config.mak' and a 'config.h' in the parent directory. See the defines
937generated by ./configure to understand what is needed.
938
939You can use libavcodec or libavformat in your commercial program, but
940@emph{any patch you make must be published}. The best way to proceed is
941to send your patches to the FFmpeg mailing list.
942
943@node Coding Rules
944@section Coding Rules
945
946FFmpeg is programmed in the ISO C90 language with a few additional
947features from ISO C99, namely:
948@itemize @bullet
949@item
950the @samp{inline} keyword;
951@item
952@samp{//} comments;
953@item
954designated struct initializers (@samp{struct s x = @{ .i = 17 @};})
955@item
956compound literals (@samp{x = (struct s) @{ 17, 23 @};})
957@end itemize
958
959These features are supported by all compilers we care about, so we will not
960accept patches to remove their use unless they absolutely do not impair
961clarity and performance.
962
963All code must compile with GCC 2.95 and GCC 3.3. Currently, FFmpeg also
964compiles with several other compilers, such as the Compaq ccc compiler
965or Sun Studio 9, and we would like to keep it that way unless it would
966be exceedingly involved. To ensure compatibility, please do not use any
967additional C99 features or GCC extensions. Especially watch out for:
968@itemize @bullet
969@item
970mixing statements and declarations;
971@item
972@samp{long long} (use @samp{int64_t} instead);
973@item
974@samp{__attribute__} not protected by @samp{#ifdef __GNUC__} or similar;
975@item
976GCC statement expressions (@samp{(x = (@{ int y = 4; y; @})}).
977@end itemize
978
979Indent size is 4.
980The presentation is the one specified by 'indent -i4 -kr -nut'.
981The TAB character is forbidden outside of Makefiles as is any
982form of trailing whitespace. Commits containing either will be
983rejected by the Subversion repository.
984
985The main priority in FFmpeg is simplicity and small code size in order to
986minimize the bug count.
987
988Comments: Use the JavaDoc/Doxygen
989format (see examples below) so that code documentation
990can be generated automatically. All nontrivial functions should have a comment
991above them explaining what the function does, even if it is just one sentence.
992All structures and their member variables should be documented, too.
993@example
994/**
995 * @@file mpeg.c
996 * MPEG codec.
997 * @@author ...
998 */
999
1000/**
1001 * Summary sentence.
1002 * more text ...
1003 * ...
1004 */
1005typedef struct Foobar@{
1006 int var1; /**< var1 description */
1007 int var2; ///< var2 description
1008 /** var3 description */
1009 int var3;
1010@} Foobar;
1011
1012/**
1013 * Summary sentence.
1014 * more text ...
1015 * ...
1016 * @@param my_parameter description of my_parameter
1017 * @@return return value description
1018 */
1019int myfunc(int my_parameter)
1020...
1021@end example
1022
1023fprintf and printf are forbidden in libavformat and libavcodec,
1024please use av_log() instead.
1025
1026Casts should be used only when necessary. Unneeded parentheses
1027should also be avoided if they don't make the code easier to understand.
1028
1029@section Development Policy
1030
1031@enumerate
1032@item
1033 Contributions should be licensed under the LGPL 2.1, including an
1034 "or any later version" clause, or the MIT license. GPL 2 including
1035 an "or any later version" clause is also acceptable, but LGPL is
1036 preferred.
1037@item
1038 You must not commit code which breaks FFmpeg! (Meaning unfinished but
1039 enabled code which breaks compilation or compiles but does not work or
1040 breaks the regression tests)
1041 You can commit unfinished stuff (for testing etc), but it must be disabled
1042 (#ifdef etc) by default so it does not interfere with other developers'
1043 work.
1044@item
1045 You do not have to over-test things. If it works for you, and you think it
1046 should work for others, then commit. If your code has problems
1047 (portability, triggers compiler bugs, unusual environment etc) they will be
1048 reported and eventually fixed.
1049@item
1050 Do not commit unrelated changes together, split them into self-contained
1051 pieces. Also do not forget that if part B depends on part A, but A does not
1052 depend on B, then A can and should be committed first and separate from B.
1053 Keeping changes well split into self-contained parts makes reviewing and
1054 understanding them on the commit log mailing list easier. This also helps
1055 in case of debugging later on.
1056 Also if you have doubts about splitting or not splitting, do not hesitate to
1057 ask/discuss it on the developer mailing list.
1058@item
1059 Do not change behavior of the program (renaming options etc) without
1060 first discussing it on the ffmpeg-devel mailing list. Do not remove
1061 functionality from the code. Just improve!
1062
1063 Note: Redundant code can be removed.
1064@item
1065 Do not commit changes to the build system (Makefiles, configure script)
1066 which change behavior, defaults etc, without asking first. The same
1067 applies to compiler warning fixes, trivial looking fixes and to code
1068 maintained by other developers. We usually have a reason for doing things
1069 the way we do. Send your changes as patches to the ffmpeg-devel mailing
1070 list, and if the code maintainers say OK, you may commit. This does not
1071 apply to files you wrote and/or maintain.
1072@item
1073 We refuse source indentation and other cosmetic changes if they are mixed
1074 with functional changes, such commits will be rejected and removed. Every
1075 developer has his own indentation style, you should not change it. Of course
1076 if you (re)write something, you can use your own style, even though we would
1077 prefer if the indentation throughout FFmpeg was consistent (Many projects
1078 force a given indentation style - we do not.). If you really need to make
1079 indentation changes (try to avoid this), separate them strictly from real
1080 changes.
1081
1082 NOTE: If you had to put if()@{ .. @} over a large (> 5 lines) chunk of code,
1083 then either do NOT change the indentation of the inner part within (do not
1084 move it to the right)! or do so in a separate commit
1085@item
1086 Always fill out the commit log message. Describe in a few lines what you
1087 changed and why. You can refer to mailing list postings if you fix a
1088 particular bug. Comments such as "fixed!" or "Changed it." are unacceptable.
1089@item
1090 If you apply a patch by someone else, include the name and email address in
1091 the log message. Since the ffmpeg-cvslog mailing list is publicly
1092 archived you should add some SPAM protection to the email address. Send an
1093 answer to ffmpeg-devel (or wherever you got the patch from) saying that
1094 you applied the patch.
1095@item
1096 When applying patches that have been discussed (at length) on the mailing
1097 list, reference the thread in the log message.
1098@item
1099 Do NOT commit to code actively maintained by others without permission.
1100 Send a patch to ffmpeg-devel instead. If no one answers within a reasonable
1101 timeframe (12h for build failures and security fixes, 3 days small changes,
1102 1 week for big patches) then commit your patch if you think it is OK.
1103 Also note, the maintainer can simply ask for more time to review!
1104@item
1105 Subscribe to the ffmpeg-cvslog mailing list. The diffs of all commits
1106 are sent there and reviewed by all the other developers. Bugs and possible
1107 improvements or general questions regarding commits are discussed there. We
1108 expect you to react if problems with your code are uncovered.
1109@item
1110 Update the documentation if you change behavior or add features. If you are
1111 unsure how best to do this, send a patch to ffmpeg-devel, the documentation
1112 maintainer(s) will review and commit your stuff.
1113@item
1114 Try to keep important discussions and requests (also) on the public
1115 developer mailing list, so that all developers can benefit from them.
1116@item
1117 Never write to unallocated memory, never write over the end of arrays,
1118 always check values read from some untrusted source before using them
1119 as array index or other risky things.
1120@item
1121 Remember to check if you need to bump versions for the specific libav
1122 parts (libavutil, libavcodec, libavformat) you are changing. You need
b98052d5 1123 to change the version integer.
d0e1cd3d
DB
1124 Incrementing the first component means no backward compatibility to
1125 previous versions (e.g. removal of a function from the public API).
1126 Incrementing the second component means backward compatible change
b98052d5
PR
1127 (e.g. addition of a function to the public API or extension of an
1128 existing data structure).
d0e1cd3d
DB
1129 Incrementing the third component means a noteworthy binary compatible
1130 change (e.g. encoder bug fix that matters for the decoder).
1131@item
53407b64 1132 Compiler warnings indicate potential bugs or code with bad style. If a type of
9908c1a8
DB
1133 warning always points to correct and clean code, that warning should
1134 be disabled, not the code changed.
1135 Thus the remaining warnings can either be bugs or correct code.
beaa4a91 1136 If it is a bug, the bug has to be fixed. If it is not, the code should
9908c1a8
DB
1137 be changed to not generate a warning unless that causes a slowdown
1138 or obfuscates the code.
d0e1cd3d
DB
1139@item
1140 If you add a new file, give it a proper license header. Do not copy and
1141 paste it from a random place, use an existing file as template.
1142@end enumerate
1143
1144We think our rules are not too hard. If you have comments, contact us.
1145
1146Note, these rules are mostly borrowed from the MPlayer project.
1147
1148@section Submitting patches
1149
1150First, (@pxref{Coding Rules}) above if you did not yet.
1151
1152When you submit your patch, try to send a unified diff (diff '-up'
1153option). We cannot read other diffs :-)
1154
1155Also please do not submit a patch which contains several unrelated changes.
1156Split it into separate, self-contained pieces. This does not mean splitting
1157file by file. Instead, make the patch as small as possible while still
1158keeping it as a logical unit that contains an individual change, even
1159if it spans multiple files. This makes reviewing your patches much easier
1160for us and greatly increases your chances of getting your patch applied.
1161
1162Run the regression tests before submitting a patch so that you can
1163verify that there are no big problems.
1164
1165Patches should be posted as base64 encoded attachments (or any other
1166encoding which ensures that the patch will not be trashed during
1167transmission) to the ffmpeg-devel mailing list, see
1168@url{http://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel}
1169
1170It also helps quite a bit if you tell us what the patch does (for example
1171'replaces lrint by lrintf'), and why (for example '*BSD isn't C99 compliant
1172and has no lrint()')
1173
1174Also please if you send several patches, send each patch as a separate mail,
1175do not attach several unrelated patches to the same mail.
1176
28ce1839
RP
1177@section New codecs or formats checklist
1178
1179@enumerate
1180@item
1181 Did you use av_cold for codec initialization and close functions?
1182@item
1183 Did you add a long_name under NULL_IF_CONFIG_SMALL to the AVCodec or
1184 AVInputFormat/AVOutputFormat struct?
1185@item
1186 Did you bump the minor version number in @file{avcodec.h} or
1187 @file{avformat.h}?
1188@item
1189 Did you register it in @file{allcodecs.c} or @file{allformats.c}?
1190@item
1191 Did you add the CodecID to @file{avcodec.h}?
1192@item
1193 If it has a fourcc, did you add it to @file{libavformat/riff.c},
1194 even if it is only a decoder?
1195@item
1196 Did you add a rule to compile the appropriate files in the Makefile?
1197 Remember to do this even if you're just adding a format to a file that is
1198 already being compiled by some other rule, like a raw demuxer.
1199@item
1200 Did you add an entry to the table of supported formats or codecs in the
1201 documentation?
1202@item
1203 Did you add an entry in the Changelog?
1204@item
1205 If it depends on a parser or a library, did you add that dependency in
1206 configure?
1207@item
1208 Did you "svn add" the appropriate files before commiting?
1209@end enumerate
1210
d0e1cd3d
DB
1211@section patch submission checklist
1212
1213@enumerate
1214@item
1215 Do the regression tests pass with the patch applied?
1216@item
2cdba8bf
DB
1217 Does @code{make checkheaders} pass with the patch applied?
1218@item
d0e1cd3d
DB
1219 Is the patch a unified diff?
1220@item
1221 Is the patch against latest FFmpeg SVN?
1222@item
1223 Are you subscribed to ffmpeg-dev?
1224 (the list is subscribers only due to spam)
1225@item
1226 Have you checked that the changes are minimal, so that the same cannot be
1227 achieved with a smaller patch and/or simpler final code?
1228@item
1229 If the change is to speed critical code, did you benchmark it?
1230@item
1231 If you did any benchmarks, did you provide them in the mail?
1232@item
1233 Have you checked that the patch does not introduce buffer overflows or
1234 other security issues?
1235@item
63d247ea
DB
1236 Did you test your decoder or demuxer against damaged data? If no, see
1237 tools/trasher and the noise bitstream filter. Your decoder or demuxer
1238 should not crash or end in a (near) infinite loop when fed damaged data.
b885e0db 1239@item
d0e1cd3d
DB
1240 Is the patch created from the root of the source tree, so it can be
1241 applied with @code{patch -p0}?
1242@item
1243 Does the patch not mix functional and cosmetic changes?
1244@item
1245 Did you add tabs or trailing whitespace to the code? Both are forbidden.
1246@item
1247 Is the patch attached to the email you send?
1248@item
1249 Is the mime type of the patch correct? It should be text/x-diff or
1250 text/x-patch or at least text/plain and not application/octet-stream.
1251@item
1252 If the patch fixes a bug, did you provide a verbose analysis of the bug?
1253@item
1254 If the patch fixes a bug, did you provide enough information, including
1255 a sample, so the bug can be reproduced and the fix can be verified?
1256 Note please do not attach samples >100k to mails but rather provide a
0fa5f24c 1257 URL, you can upload to ftp://upload.ffmpeg.org
d0e1cd3d
DB
1258@item
1259 Did you provide a verbose summary about what the patch does change?
1260@item
1261 Did you provide a verbose explanation why it changes things like it does?
1262@item
1263 Did you provide a verbose summary of the user visible advantages and
1264 disadvantages if the patch is applied?
1265@item
1266 Did you provide an example so we can verify the new feature added by the
1267 patch easily?
1268@item
1269 If you added a new file, did you insert a license header? It should be
1270 taken from FFmpeg, not randomly copied and pasted from somewhere else.
1271@item
1272 You should maintain alphabetical order in alphabetically ordered lists as
1273 long as doing so does not break API/ABI compatibility.
1274@item
1275 Lines with similar content should be aligned vertically when doing so
1276 improves readability.
1277@item
1278 Did you provide a suggestion for a clear commit log message?
1279@end enumerate
1280
1281@section Patch review process
1282
1283All patches posted to ffmpeg-devel will be reviewed, unless they contain a
1284clear note that the patch is not for SVN.
1285Reviews and comments will be posted as replies to the patch on the
1286mailing list. The patch submitter then has to take care of every comment,
1287that can be by resubmitting a changed patch or by discussion. Resubmitted
1288patches will themselves be reviewed like any other patch. If at some point
1289a patch passes review with no comments then it is approved, that can for
1290simple and small patches happen immediately while large patches will generally
1291have to be changed and reviewed many times before they are approved.
1292After a patch is approved it will be committed to the repository.
1293
1294We will review all submitted patches, but sometimes we are quite busy so
1295especially for large patches this can take several weeks.
1296
1297When resubmitting patches, please do not make any significant changes
1298not related to the comments received during review. Such patches will
1299be rejected. Instead, submit significant changes or new features as
1300separate patches.
1301
1302@section Regression tests
1303
1304Before submitting a patch (or committing to the repository), you should at least
1305test that you did not break anything.
1306
1307The regression tests build a synthetic video stream and a synthetic
1308audio stream. These are then encoded and decoded with all codecs or
1309formats. The CRC (or MD5) of each generated file is recorded in a
1310result file. A 'diff' is launched to compare the reference results and
1311the result file.
1312
1313The regression tests then go on to test the FFserver code with a
1314limited set of streams. It is important that this step runs correctly
1315as well.
1316
1317Run 'make test' to test all the codecs and formats.
1318
1319Run 'make fulltest' to test all the codecs, formats and FFserver.
1320
1321[Of course, some patches may change the results of the regression tests. In
1322this case, the reference results of the regression tests shall be modified
1323accordingly].
1324
1325@bye