Merge MP2, MP3 and MPEG audio demuxer entries.
[libav.git] / doc / general.texi
1 \input texinfo @c -*- texinfo -*-
3 @settitle General Documentation
4 @titlepage
5 @sp 7
6 @center @titlefont{General Documentation}
7 @sp 3
8 @end titlepage
11 @chapter external libraries
13 FFmpeg can be hooked up with a number of external libraries to add support
14 for more formats. None of them are used by default, their use has to be
15 explicitly requested by passing the appropriate flags to @file{./configure}.
17 @section AMR
19 AMR comes in two different flavors, wideband and narrowband. FFmpeg can make
20 use of the AMR wideband (floating-point mode) and the AMR narrowband
21 (floating-point mode) reference decoders and encoders.
23 Go to @url{} and follow the instructions for
24 installing the libraries. Then pass @code{--enable-libamr-nb} and/or
25 @code{--enable-libamr-wb} to configure to enable the libraries.
27 Note that libamr is copyrighted without any sort of license grant. This means
28 that you can use it if you legally obtained it but you are not allowed to
29 redistribute it in any way. @strong{Any FFmpeg binaries with libamr support
30 you create are non-free and unredistributable!}
33 @chapter Supported File Formats and Codecs
35 You can use the @code{-formats} option to have an exhaustive list.
37 @section File Formats
39 FFmpeg supports the following file formats through the @code{libavformat}
40 library:
42 @multitable @columnfractions .4 .1 .1 .4
43 @item Name @tab Encoding @tab Decoding @tab Comments
44 @item 4xm @tab @tab X
45 @tab 4X Technologies format, used in some games.
46 @item Audio IFF (AIFF) @tab X @tab X
47 @item American Laser Games MM @tab @tab X
48 @tab Multimedia format used in games like Mad Dog McCree.
49 @item 3GPP AMR @tab X @tab X
50 @item ASF @tab X @tab X
51 @item AVI @tab X @tab X
52 @item AVISynth @tab @tab X
53 @item AVS @tab @tab X
54 @tab Multimedia format used by the Creature Shock game.
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
58 @tab Used in some games from Bethesda Softworks.
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
62 @tab Used in the game Cyberia from Interplay.
63 @item Delphine Software International CIN @tab @tab X
64 @tab Multimedia format used by Delphine Software games.
65 @item CRC testing format @tab X @tab
66 @item Creative Voice @tab X @tab X
67 @tab Created for the Sound Blaster Pro.
68 @item CRYO APC @tab @tab X
69 @tab Audio format used in some games by CRYO Interactive Entertainment.
70 @item D-Cinema audio @tab X @tab X
71 @item DV video @tab X @tab X
72 @item DXA @tab @tab X
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.
75 @item Electronic Arts cdata @tab @tab X
76 @item Electronic Arts Multimedia @tab @tab X
77 @tab Used in various EA games; files have extensions like WVE and UV2.
78 @item FFM (FFserver live feed) @tab X @tab X
79 @item Flash (SWF) @tab X @tab X
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
83 @tab .fli/.flc files
84 @item FLV @tab X @tab X
85 @tab Macromedia Flash video files
86 @item framecrc testing format @tab X @tab
87 @item FunCom ISS @tab @tab X
88 @tab Audio format used in various games from FunCom like The Longest Journey.
89 @item GIF Animation @tab X @tab
90 @item GXF @tab X @tab X
91 @tab General eXchange Format SMPTE 360M, used by Thomson Grass Valley
92 playout servers.
93 @item id Cinematic @tab @tab X
94 @tab Used in Quake II.
95 @item id RoQ @tab X @tab X
96 @tab Used in Quake III, Jedi Knight 2, other computer games.
97 @item IFF @tab @tab X
98 @tab Interchange File Format
99 @item Interplay MVE @tab @tab X
100 @tab Format used in various Interplay computer games.
101 @item LMLM4 @tab @tab X
102 @tab Used by Linux Media Labs MPEG-4 PCI boards
103 @item Matroska @tab X @tab X
104 @item Matroska audio @tab X @tab
105 @item MAXIS XA @tab @tab X
106 @tab Used in Sim City 3000; file extension .xa.
107 @item Monkey's Audio @tab @tab X
108 @item Motion Pixels MVI @tab @tab X
109 @item MOV/QuickTime/MP4 @tab X @tab X
110 @tab 3GP, 3GP2, PSP, iPod variants supported
111 @item MP2 @tab X @tab X
112 @item MP3 @tab X @tab X
113 @item MPEG-1 System @tab X @tab X
114 @tab muxed audio and video, VCD format supported
115 @item MPEG-PS (program stream) @tab X @tab X
116 @tab also known as @code{VOB} file, SVCD and DVD format supported
117 @item MPEG-TS (transport stream) @tab X @tab X
118 @tab also known as DVB Transport Stream
119 @item MPEG-4 @tab X @tab X
120 @tab MPEG-4 is a variant of QuickTime.
121 @item MIME multipart JPEG @tab X @tab
122 @item MSN TCP webcam @tab @tab X
123 @tab Used by MSN Messenger webcam streams.
124 @item MTV @tab @tab X
125 @item Musepack @tab @tab X
126 @item Musepack SV8 @tab @tab X
127 @item Material eXchange Format (MXF) @tab X @tab X
128 @tab SMPTE 377M, used by D-Cinema, broadcast industry.
129 @item Material eXchange Format (MXF), D-10 Mapping @tab X @tab X
130 @tab SMPTE 386M, D-10/IMX Mapping.
131 @item NC camera feed @tab @tab X
132 @tab NC (AVIP NC4600) camera streams
133 @item Nullsoft Streaming Video @tab @tab X
134 @item NuppelVideo @tab @tab X
135 @item NUT @tab X @tab X
136 @tab NUT Open Container Format
137 @item Ogg @tab X @tab X
138 @item TechnoTrend PVA @tab @tab X
139 @tab Used by TechnoTrend DVB PCI boards.
140 @item raw ADTS (AAC) @tab X @tab X
141 @item raw AC-3 @tab X @tab X
142 @item raw Chinese AVS video @tab @tab X
143 @item raw CRI ADX @tab X @tab X
144 @item raw Dirac @tab X @tab X
145 @item raw DNxHD @tab X @tab X
146 @item raw DTS @tab X @tab X
147 @item raw E-AC-3 @tab X @tab X
148 @item raw FLAC @tab X @tab X
149 @item raw GSM @tab @tab X
150 @item raw H.261 @tab X @tab X
151 @item raw H.263 @tab X @tab X
152 @item raw H.264 @tab X @tab X
153 @item raw Ingenient MJPEG @tab @tab X
154 @item raw MJPEG @tab X @tab X
155 @item raw MLP @tab @tab X
156 @item raw MPEG @tab @tab X
157 @item raw MPEG-1 @tab @tab X
158 @item raw MPEG-2 @tab @tab X
159 @item raw MPEG-4 @tab X @tab X
160 @item raw NULL @tab X @tab
161 @item raw video @tab X @tab X
162 @item raw id RoQ @tab X @tab
163 @item raw Shorten @tab @tab X
164 @item raw VC-1 @tab @tab X
165 @item raw PCM A-law @tab X @tab X
166 @item raw PCM mu-law @tab X @tab X
167 @item raw PCM signed 8 bit @tab X @tab X
168 @item raw PCM signed 16 bit big-endian @tab X @tab X
169 @item raw PCM signed 16 bit little-endian @tab X @tab X
170 @item raw PCM signed 24 bit big-endian @tab X @tab X
171 @item raw PCM signed 24 bit little-endian @tab X @tab X
172 @item raw PCM signed 32 bit big-endian @tab X @tab X
173 @item raw PCM signed 32 bit little-endian @tab X @tab X
174 @item raw PCM unsigned 8 bit @tab X @tab X
175 @item raw PCM unsigned 16 bit big-endian @tab X @tab X
176 @item raw PCM unsigned 16 bit little-endian @tab X @tab X
177 @item raw PCM unsigned 24 bit big-endian @tab X @tab X
178 @item raw PCM unsigned 24 bit little-endian @tab X @tab X
179 @item raw PCM unsigned 32 bit big-endian @tab X @tab X
180 @item raw PCM unsigned 32 bit little-endian @tab X @tab X
181 @item raw PCM floating-point 32 bit big-endian @tab X @tab X
182 @item raw PCM floating-point 32 bit little-endian @tab X @tab X
183 @item raw PCM floating-point 64 bit big-endian @tab X @tab X
184 @item raw PCM floating-point 64 bit little-endian @tab X @tab X
185 @item RDT @tab @tab X
186 @item REDCODE R3D @tab @tab X
187 @tab File format used by RED Digital cameras, contains JPEG 2000 frames and PCM audio.
188 @item RealMedia @tab X @tab X
189 @item Redirector @tab @tab X
190 @item Renderware TeXture Dictionary @tab @tab X
191 @item RL2 @tab @tab X
192 @tab Audio and video format used in some games by Entertainment Software Partners.
193 @item RPL/ARMovie @tab @tab X
194 @item RTP @tab @tab X
195 @item RTSP @tab @tab X
196 @item SDP @tab @tab X
197 @item Sega FILM/CPK @tab @tab X
198 @tab Used in many Sega Saturn console games.
199 @item Sierra SOL @tab @tab X
200 @tab .sol files used in Sierra Online games.
201 @item Sierra VMD @tab @tab X
202 @tab Used in Sierra CD-ROM games.
203 @item Smacker @tab @tab X
204 @tab Multimedia format used by many games.
205 @item Sony OpenMG (OMA) @tab @tab X
206 @tab Audio format used in Sony Sonic Stage and Sony Vegas.
207 @item Sony PlayStation STR @tab @tab X
208 @item SUN AU format @tab X @tab X
209 @item THP @tab @tab X
210 @tab Used on the Nintendo GameCube.
211 @item Tiertex Limited SEQ @tab @tab X
212 @tab Tiertex .seq files used in the DOS CD-ROM version of the game Flashback.
213 @item True Audio @tab @tab X
214 @item VC-1 test bitstream @tab X @tab X
215 @item WAV @tab X @tab X
216 @item WavPack @tab @tab X
217 @item Wing Commander III movie @tab @tab X
218 @tab Multimedia format used in Origin's Wing Commander III computer game.
219 @item Westwood Studios audio @tab @tab X
220 @tab Multimedia format used in Westwood Studios games.
221 @item Westwood Studios VQA @tab @tab X
222 @tab Multimedia format used in Westwood Studios games.
223 @item YUV4MPEG pipe @tab X @tab X
224 @end multitable
226 @code{X} means that encoding (resp. decoding) is supported.
228 @section Image Formats
230 FFmpeg can read and write images for each frame of a video sequence. The
231 following image formats are supported:
233 @multitable @columnfractions .4 .1 .1 .4
234 @item Name @tab Encoding @tab Decoding @tab Comments
235 @item .Y.U.V @tab X @tab X
236 @tab one raw file per component
237 @item animated GIF @tab X @tab X
238 @tab Only uncompressed GIFs are generated.
239 @item BMP @tab X @tab X
240 @tab Microsoft BMP image
241 @item JPEG @tab X @tab X
242 @tab Progressive JPEG is not supported.
243 @item JPEG 2000 @tab @tab E
244 @tab decoding supported through external library libopenjpeg
245 @item JPEG-LS @tab X @tab X
246 @item LJPEG @tab X @tab
247 @tab Lossless JPEG
248 @item PAM @tab X @tab X
249 @tab PAM is a PNM extension with alpha support.
250 @item PBM @tab X @tab X
251 @tab Portable BitMap image
252 @item PCX @tab @tab X
253 @tab PC Paintbrush
254 @item PGM @tab X @tab X
255 @tab Portable GrayMap image
256 @item PGMYUV @tab X @tab X
257 @tab PGM with U and V components in YUV 4:2:0
258 @item PNG @tab X @tab X
259 @tab 2/4 bpp not supported yet
260 @item PPM @tab X @tab X
261 @tab Portable PixelMap image
262 @item PTX @tab @tab X
263 @tab V.Flash PTX format
264 @item RAS @tab @tab X
265 @tab Sun Rasterfile
266 @item SGI @tab X @tab X
267 @tab SGI RGB image format
268 @item Targa @tab X @tab X
269 @tab Targa (.TGA) image format
270 @item TIFF @tab X @tab X
271 @tab YUV, JPEG and some extension is not supported yet.
272 @end multitable
274 @code{X} means that encoding (resp. decoding) is supported.
276 @code{E} means that support is provided through an external library.
278 @section Video Codecs
280 @multitable @columnfractions .4 .1 .1 .4
281 @item Name @tab Encoding @tab Decoding @tab Comments
282 @item 4X Movie @tab @tab X
283 @tab Used in certain computer games.
284 @item 8SVX exponential @tab @tab X
285 @item 8SVX fibonacci @tab @tab X
286 @item American Laser Games MM @tab @tab X
287 @tab Used in games like Mad Dog McCree.
288 @item AMV @tab @tab X
289 @tab Used in Chinese MP3 players.
290 @item Apple Animation @tab X @tab X
291 @tab fourcc: 'rle '
292 @item Apple Graphics @tab @tab X
293 @tab fourcc: 'smc '
294 @item Apple MJPEG-B @tab @tab X
295 @item Apple QuickDraw @tab @tab X
296 @tab fourcc: qdrw
297 @item Apple Video @tab @tab X
298 @tab fourcc: rpza
299 @item Asus v1 @tab X @tab X
300 @tab fourcc: ASV1
301 @item Asus v2 @tab X @tab X
302 @tab fourcc: ASV2
303 @item ATI VCR1 @tab @tab X
304 @tab fourcc: VCR1
305 @item ATI VCR2 @tab @tab X
306 @tab fourcc: VCR2
307 @item Autodesk RLE @tab @tab X
308 @tab fourcc: AASC
309 @item AVS (Audio Video Standard) video @tab @tab X
310 @tab Video encoding used by the Creature Shock game.
311 @item Beam Software VB @tab @tab X
312 @item Bethesda VID video @tab @tab X
313 @tab Used in some games from Bethesda Softworks.
314 @item Brute Force & Ignorance @tab @tab X
315 @tab Used in the game Flash Traffic: City of Angels.
316 @item C93 video @tab @tab X
317 @tab Codec used in Cyberia game.
318 @item CamStudio @tab @tab X
319 @tab fourcc: CSCD
320 @item Chinese AVS video @tab @tab X
321 @tab AVS1-P2, JiZhun profile
322 @item Delphine Software International CIN video @tab @tab X
323 @tab Codec used in Delphine Software International games.
324 @item Cinepak @tab @tab X
325 @item Cirrus Logic AccuPak @tab @tab X
326 @tab fourcc: CLJR
327 @item Creative YUV (CYUV) @tab @tab X
328 @item Dirac @tab E @tab E
329 @tab supported through external libdirac/libschroedinger libraries
330 @item DNxHD @tab X @tab X
331 @tab aka SMPTE VC3
332 @item Duck TrueMotion 1.0 @tab @tab X
333 @tab fourcc: DUCK
334 @item Duck TrueMotion 2.0 @tab @tab X
335 @tab fourcc: TM20
336 @item DV (Digital Video) @tab X @tab X
337 @item Feeble Files/ScummVM DXA @tab @tab X
338 @tab Codec originally used in Feeble Files game.
339 @item Electronic Arts CMV video @tab @tab X
340 @tab Used in NHL 95 game.
341 @item Electronic Arts TGV @tab @tab X
342 @item Electronic Arts TGQ @tab @tab X
343 @item Electronic Arts TQI @tab @tab X
344 @item FFmpeg Video 1 @tab X @tab X
345 @tab experimental lossless codec (fourcc: FFV1)
346 @item Flash Screen Video @tab X @tab X
347 @tab fourcc: FSV1
348 @item FLIC video @tab @tab X
349 @item FLV @tab X @tab X
350 @tab Sorenson H.263 used in Flash
351 @item Fraps FPS1 @tab @tab X
352 @item H.261 @tab X @tab X
353 @item H.263(+) @tab X @tab X
354 @tab also known as RealVideo 1.0
355 @item H.264 @tab E @tab X
356 @tab encoding supported through external library libx264
357 @item HuffYUV @tab X @tab X
358 @item IBM Ultimotion @tab @tab X
359 @tab fourcc: ULTI
360 @item id Cinematic video @tab @tab X
361 @tab Used in Quake II.
362 @item id RoQ @tab X @tab X
363 @tab Used in Quake III, Jedi Knight 2, other computer games.
364 @item Intel Indeo 3 @tab @tab X
365 @item Interplay C93 @tab @tab X
366 @tab Used in the game Cyberia from Interplay.
367 @item Interplay Video @tab @tab X
368 @tab Used in Interplay .MVE files.
369 @item JPEG-LS @tab X @tab X
370 @tab fourcc: MJLS, lossless and near-lossless is supported.
371 @item KMVC @tab @tab X
372 @tab Codec used in Worms games.
373 @item LOCO @tab @tab X
374 @item lossless MJPEG @tab X @tab X
375 @item Microsoft RLE @tab @tab X
376 @item Microsoft Video-1 @tab @tab X
377 @item Mimic @tab @tab X
378 @tab Used in MSN Messenger Webcam streams.
379 @item Miro VideoXL @tab @tab X
380 @tab fourcc: VIXL
381 @item MJPEG (Motion JPEG) @tab X @tab X
382 @item Motion Pixels Video @tab @tab X
383 @item MPEG-1 @tab X @tab X
384 @item MPEG-2 @tab X @tab X
385 @item MPEG-4 @tab X @tab X
386 @item MSMPEG4 V1 @tab X @tab X
387 @item MSMPEG4 V2 @tab X @tab X
388 @item MSMPEG4 V3 @tab X @tab X
389 @item MSZH @tab @tab X
390 @tab Part of LCL
391 @item Nintendo Gamecube THP video @tab @tab X
392 @item On2 VP3 @tab @tab X
393 @tab still experimental
394 @item On2 VP5 @tab @tab X
395 @tab fourcc: VP50
396 @item On2 VP6 @tab @tab X
397 @tab fourcc: VP60,VP61,VP62
398 @item planar RGB @tab @tab X
399 @tab fourcc: 8BPS
400 @item QPEG @tab @tab X
401 @tab fourccs: QPEG, Q1.0, Q1.1
402 @item QuickTime 8BPS video @tab @tab X
403 @item RealVideo 1.0 @tab X @tab X
404 @item RealVideo 2.0 @tab X @tab X
405 @item RealVideo 3.0 @tab @tab X
406 @tab still far from ideal
407 @item RealVideo 4.0 @tab @tab X
408 @item Renderware TXD (TeXture Dictionary) @tab @tab X
409 @tab Texture dictionaries used by the Renderware Engine.
410 @item RTjpeg @tab @tab X
411 @tab Video encoding used in NuppelVideo files.
412 @item Sierra VMD video @tab @tab X
413 @tab Used in Sierra VMD files.
414 @item Smacker video @tab @tab X
415 @tab Video encoding used in Smacker.
416 @item SMPTE VC-1 @tab @tab X
417 @item Snow @tab X @tab X
418 @tab experimental wavelet codec (fourcc: SNOW)
419 @item Sony PlayStation MDEC (Motion DECoder) @tab @tab X
420 @item Sorenson Video 1 @tab X @tab X
421 @tab fourcc: SVQ1
422 @item Sorenson Video 3 @tab @tab X
423 @tab fourcc: SVQ3
424 @item Sunplus MJPEG @tab @tab X
425 @tab fourcc: SP5X
426 @item TechSmith Screen Capture Codec @tab @tab X
427 @tab fourcc: TSCC
428 @item Theora @tab E @tab X
429 @tab encoding supported through external library libtheora
430 @item Tiertex Seq video @tab @tab X
431 @tab Codec used in DOS CD-ROM FlashBack game.
432 @item VMware Screen Codec / VMware Video @tab @tab X
433 @tab Codec used in videos captured by VMware.
434 @item Westwood Studios VQA (Vector Quantized Animation) video @tab @tab X
435 @item Windows Media Video 8 @tab X @tab X
436 @item Windows Media Video 9 @tab @tab X
437 @tab not completely working
438 @item Wing Commander III / Xan @tab @tab X
439 @tab Used in Wing Commander III .MVE files.
440 @item Winnov WNV1 @tab @tab X
441 @item WMV7 @tab X @tab X
442 @item YAMAHA SMAF @tab X @tab X
443 @item ZLIB @tab X @tab X
444 @tab part of LCL, encoder experimental
445 @item Zip Motion Blocks Video @tab X @tab X
446 @tab Encoder works only in PAL8.
447 @end multitable
449 @code{X} means that encoding (resp. decoding) is supported.
451 @code{E} means that support is provided through an external library.
453 @section Audio Codecs
455 @multitable @columnfractions .4 .1 .1 .4
456 @item Name @tab Encoding @tab Decoding @tab Comments
457 @item 4X Movie ADPCM @tab @tab X
458 @item 8SVX audio @tab @tab X
459 @item AAC @tab E @tab X
460 @tab encoding supported through external library libfaac
461 @item AC-3 @tab X @tab X
462 @item AMR-NB @tab E @tab E
463 @tab supported through external library libamrnb
464 @item AMR-WB @tab E @tab E
465 @tab supported through external library libamrwb
466 @item Apple lossless audio @tab X @tab X
467 @tab QuickTime fourcc 'alac'
468 @item Apple MACE 3 @tab @tab X
469 @item Apple MACE 6 @tab @tab X
470 @item Atrac 3 @tab @tab X
471 @item CDROM XA ADPCM @tab @tab X
472 @item Delphine Software International CIN audio @tab @tab X
473 @tab Codec used in Delphine Software International games.
474 @item COOK @tab @tab X
475 @tab All versions except 5.1 are supported.
476 @item Creative Technology ADPCM @tab @tab X
477 @tab 16 -> 4, 8 -> 4, 8 -> 3, 8 -> 2
478 @item DCA (DTS Coherent Acoustics) @tab @tab X
479 @item DSP Group TrueSpeech @tab @tab X
480 @item DV audio @tab @tab X
481 @item Electronic Arts ADPCM @tab @tab X
482 @tab Used in various EA titles.
483 @item Electronic Arts Maxis CDROM XS ADPCM @tab @tab X
484 @tab Used in Sim City 3000.
485 @item Electronic Arts R1 ADPCM @tab @tab X
486 @item Electronic Arts R2 ADPCM @tab @tab X
487 @item Electronic Arts R3 ADPCM @tab @tab X
488 @item Electronic Arts XAS ADPCM @tab @tab X
489 @item Enhanced AC-3 @tab @tab X
490 @item FLAC lossless audio @tab IX @tab X
491 @item G.726 ADPCM @tab X @tab X
492 @item GSM @tab E @tab E
493 @tab supported through external library libgsm
494 @item GSM_MS @tab E @tab E
495 @tab supported through external library libgsm
496 @item id RoQ DPCM @tab X @tab X
497 @tab Used in Quake III, Jedi Knight 2, other computer games.
498 @item IMA AMV ADPCM @tab @tab X
499 @tab Used in AMV files
500 @item IMA Electronic Arts EACS ADPCM @tab @tab X
501 @item IMA Electronic Arts SEAD ADPCM @tab @tab X
502 @item IMA Funcom ADPCM @tab @tab X
503 @item IMA QuickTime ADPCM @tab X @tab X
504 @item IMA Loki SDL MJPEG ADPCM @tab @tab X
505 @item IMA WAV ADPCM @tab X @tab X
506 @item IMA Westwood ADPCM @tab @tab X
507 @item Intel Music Coder @tab @tab X
508 @item Interplay DPCM @tab @tab X
509 @tab Used in various Interplay computer games.
510 @item ISS IMA ADPCM @tab @tab X
511 @tab Used in FunCom games.
512 @item IMA Duck DK3 ADPCM @tab @tab X
513 @tab Used in some Sega Saturn console games.
514 @item IMA Duck DK4 ADPCM @tab @tab X
515 @tab Used in some Sega Saturn console games.
516 @item Microsoft ADPCM @tab X @tab X
517 @item MLP/TrueHD @tab @tab X
518 @tab Used in DVD-Audio and Blu-Ray discs.
519 @item Monkey's Audio @tab @tab X
520 @tab Only versions 3.97-3.99 are supported.
521 @item MPEG audio layer 3 @tab E @tab IX
522 @tab encoding supported through external library LAME
523 @item MPEG audio layer 2 @tab IX @tab IX
524 @item MS IMA ADPCM @tab X @tab X
525 @item Musepack @tab @tab X
526 @tab SV7 and SV8 are supported.
527 @item Nellymoser ASAO @tab X @tab X
528 @item Nintendo Gamecube THP ADPCM @tab @tab X
529 @item QCELP / PureVoice @tab @tab X
530 @item Qdesign QDM2 @tab @tab X
531 @tab There are still some distortions.
532 @item QT IMA ADPCM @tab X @tab X
533 @item RA144 @tab @tab X
534 @tab Real 14400 bit/s codec
535 @item RA288 @tab @tab X
536 @tab Real 28800 bit/s codec
537 @item RADnet @tab IX @tab IX
538 @tab Real low bitrate AC-3 codec
539 @item SEGA CRI ADX ADPCM @tab X @tab X
540 @tab Used in Sega Dreamcast games.
541 @item Shockwave Flash ADPCM @tab X @tab X
542 @item Shorten @tab @tab X
543 @item Sierra Online DPCM @tab @tab X
544 @tab Used in Sierra Online game audio files.
545 @item Sierra VMD audio @tab @tab X
546 @tab Used in Sierra VMD files.
547 @item Smacker audio @tab @tab X
548 @item SMJPEG IMA ADPCM @tab @tab X
549 @tab Used in certain Loki game ports.
550 @item Sol DPCM @tab @tab X
551 @item Sonic @tab X @tab X
552 @tab experimental codec
553 @item Sonic lossless @tab X @tab X
554 @tab experimental codec
555 @item Sound Blaster Pro 2-bit ADPCM @tab @tab X
556 @item Sound Blaster Pro 2.6-bit ADPCM @tab @tab X
557 @item Sound Blaster Pro 4-bit ADPCM @tab @tab X
558 @item Speex @tab @tab E
559 @tab supported through external library libspeex
560 @item True Audio (TTA) @tab @tab X
561 @item Vorbis @tab X @tab X
562 @item WavPack @tab @tab X
563 @item Westwood Studios IMA ADPCM @tab @tab X
564 @tab Used in Westwood Studios games like Command and Conquer.
565 @item Westwood Audio (SND1) @tab @tab X
566 @item Windows Media Audio 1 @tab X @tab X
567 @item Windows Media Audio 2 @tab X @tab X
568 @item Xan DPCM @tab @tab X
569 @tab Used in Origin's Wing Commander IV AVI files.
570 @item Yamaha ADPCM @tab X @tab X
571 @end multitable
573 @code{X} means that encoding (resp. decoding) is supported.
575 @code{E} means that support is provided through an external library.
577 @code{I} means that an integer-only version is available, too (ensures high
578 performance on systems without hardware floating point support).
580 @section Subtitle Formats
582 @multitable @columnfractions .4 .1 .1 .1 .1 .1
583 @item Name @tab Muxing @tab Demuxing @tab Encoding @tab Decoding
584 @item SSA/ASS @tab X @tab X
585 @item DVB @tab X @tab X @tab X @tab X
586 @item DVD @tab X @tab X @tab X @tab X
587 @item XSUB @tab @tab @tab @tab X
588 @end multitable
590 @code{X} means that the feature is supported.
592 @section Network Protocols
594 @multitable @columnfractions .4 .1 .1 .1 .1 .1
595 @item Name @tab Support
596 @item file @tab X
597 @item Gopher @tab X
598 @item HTTP @tab X
599 @item pipe @tab X
600 @item RTP @tab X
601 @item TCP @tab X
602 @item UDP @tab X
603 @end multitable
605 @code{X} means that the protocol is supported.
608 @chapter Platform Specific information
610 @section BSD
612 BSD make will not build FFmpeg, you need to install and use GNU Make
613 (@file{gmake}).
615 @section Windows
617 To get help and instructions for building FFmpeg under Windows, check out
618 the FFmpeg Windows Help Forum at
619 @url{}.
621 @subsection Native Windows compilation
623 FFmpeg can be built to run natively on Windows using the MinGW tools. Install
624 the latest versions of MSYS and MinGW from @url{}.
625 You can find detailed installation
626 instructions in the download section and the FAQ.
628 FFmpeg does not build out-of-the-box with the packages the automated MinGW
629 installer provides. It also requires coreutils to be installed and many other
630 packages updated to the latest version. The minimum version for some packages
631 are listed below:
633 @itemize
634 @item bash 3.1
635 @item msys-make 3.81-2 (note: not mingw32-make)
636 @item w32api 3.13
637 @item mingw-runtime 3.15
638 @end itemize
640 You will also need to pass @code{-fno-common} to the compiler to work around
641 a GCC bug (see @url{}).
643 Within the MSYS shell, configure and make with:
645 @example
646 ./configure --enable-memalign-hack --extra-cflags=-fno-common
647 make
648 make install
649 @end example
651 This will install @file{ffmpeg.exe} along with many other development files
652 to @file{/usr/local}. You may specify another install path using the
653 @code{--prefix} option in @file{configure}.
655 Notes:
657 @itemize
659 @item In order to compile vhooks, you must have a POSIX-compliant libdl in
660 your MinGW system. Get dlfcn-win32 from
661 @url{}.
663 @item In order to compile FFplay, you must have the MinGW development library
664 of SDL. Get it from @url{}.
665 Edit the @file{bin/sdl-config} script so that it points to the correct prefix
666 where SDL was installed. Verify that @file{sdl-config} can be launched from
667 the MSYS command line.
669 @item By using @code{./configure --enable-shared} when configuring FFmpeg,
670 you can build libavutil, libavcodec and libavformat as DLLs.
672 @end itemize
674 @subsection Microsoft Visual C++ compatibility
676 As stated in the FAQ, FFmpeg will not compile under MSVC++. However, if you
677 want to use the libav* libraries in your own applications, you can still
678 compile those applications using MSVC++. But the libav* libraries you link
679 to @emph{must} be built with MinGW. However, you will not be able to debug
680 inside the libav* libraries, since MSVC++ does not recognize the debug
681 symbols generated by GCC.
682 We strongly recommend you to move over from MSVC++ to MinGW tools.
684 This description of how to use the FFmpeg libraries with MSVC++ is based on
685 Microsoft Visual C++ 2005 Express Edition. If you have a different version,
686 you might have to modify the procedures slightly.
688 @subsubsection Using static libraries
690 Assuming you have just built and installed FFmpeg in @file{/usr/local}.
692 @enumerate
694 @item Create a new console application ("File / New / Project") and then
695 select "Win32 Console Application". On the appropriate page of the
696 Application Wizard, uncheck the "Precompiled headers" option.
698 @item Write the source code for your application, or, for testing, just
699 copy the code from an existing sample application into the source file
700 that MSVC++ has already created for you. For example, you can copy
701 @file{output_example.c} from the FFmpeg distribution.
703 @item Open the "Project / Properties" dialog box. In the "Configuration"
704 combo box, select "All Configurations" so that the changes you make will
705 affect both debug and release builds. In the tree view on the left hand
706 side, select "C/C++ / General", then edit the "Additional Include
707 Directories" setting to contain the path where the FFmpeg includes were
708 installed (i.e. @file{c:\msys\1.0\local\include}).
709 Do not add MinGW's include directory here, or the include files will
710 conflict with MSVC's.
712 @item Still in the "Project / Properties" dialog box, select
713 "Linker / General" from the tree view and edit the
714 "Additional Library Directories" setting to contain the @file{lib}
715 directory where FFmpeg was installed (i.e. @file{c:\msys\1.0\local\lib}),
716 the directory where MinGW libs are installed (i.e. @file{c:\mingw\lib}),
717 and the directory where MinGW's GCC libs are installed
718 (i.e. @file{C:\mingw\lib\gcc\mingw32\4.2.1-sjlj}). Then select
719 "Linker / Input" from the tree view, and add the files @file{libavformat.a},
720 @file{libavcodec.a}, @file{libavutil.a}, @file{libmingwex.a},
721 @file{libgcc.a}, and any other libraries you used (i.e. @file{libz.a})
722 to the end of "Additional Dependencies".
724 @item Now, select "C/C++ / Code Generation" from the tree view. Select
725 "Debug" in the "Configuration" combo box. Make sure that "Runtime
726 Library" is set to "Multi-threaded Debug DLL". Then, select "Release" in
727 the "Configuration" combo box and make sure that "Runtime Library" is
728 set to "Multi-threaded DLL".
730 @item Click "OK" to close the "Project / Properties" dialog box.
732 @item MSVC++ lacks some C99 header files that are fundamental for FFmpeg.
733 Get msinttypes from @url{}
734 and install it in MSVC++'s include directory
735 (i.e. @file{C:\Program Files\Microsoft Visual Studio 8\VC\include}).
737 @item MSVC++ also does not understand the @code{inline} keyword used by
738 FFmpeg, so you must add this line before @code{#include}ing libav*:
739 @example
740 #define inline _inline
741 @end example
743 @item Build your application, everything should work.
745 @end enumerate
747 @subsubsection Using shared libraries
749 This is how to create DLL and LIB files that are compatible with MSVC++:
751 @enumerate
753 @item Add a call to @file{vcvars32.bat} (which sets up the environment
754 variables for the Visual C++ tools) as the first line of @file{msys.bat}.
755 The standard location for @file{vcvars32.bat} is
756 @file{C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat},
757 and the standard location for @file{msys.bat} is @file{C:\msys\1.0\msys.bat}.
758 If this corresponds to your setup, add the following line as the first line
759 of @file{msys.bat}:
761 @example
762 call "C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat"
763 @end example
765 Alternatively, you may start the @file{Visual Studio 2005 Command Prompt},
766 and run @file{c:\msys\1.0\msys.bat} from there.
768 @item Within the MSYS shell, run @code{lib.exe}. If you get a help message
769 from @file{Microsoft (R) Library Manager}, this means your environment
770 variables are set up correctly, the @file{Microsoft (R) Library Manager}
771 is on the path and will be used by FFmpeg to create
772 MSVC++-compatible import libraries.
774 @item Build FFmpeg with
776 @example
777 ./configure --enable-shared --enable-memalign-hack
778 make
779 make install
780 @end example
782 Your install path (@file{/usr/local/} by default) should now have the
783 necessary DLL and LIB files under the @file{bin} directory.
785 @end enumerate
787 To use those files with MSVC++, do the same as you would do with
788 the static libraries, as described above. But in Step 4,
789 you should only need to add the directory where the LIB files are installed
790 (i.e. @file{c:\msys\usr\local\bin}). This is not a typo, the LIB files are
791 installed in the @file{bin} directory. And instead of adding @file{libxx.a}
792 files, you should add @file{avcodec.lib}, @file{avformat.lib}, and
793 @file{avutil.lib}. There should be no need for @file{libmingwex.a},
794 @file{libgcc.a}, and @file{wsock32.lib}, nor any other external library
795 statically linked into the DLLs. The @file{bin} directory contains a bunch
796 of DLL files, but the ones that are actually used to run your application
797 are the ones with a major version number in their filenames
798 (i.e. @file{avcodec-51.dll}).
800 @subsection Cross compilation for Windows with Linux
802 You must use the MinGW cross compilation tools available at
803 @url{}.
805 Then configure FFmpeg with the following options:
806 @example
807 ./configure --target-os=mingw32 --cross-prefix=i386-mingw32msvc-
808 @end example
809 (you can change the cross-prefix according to the prefix chosen for the
810 MinGW tools).
812 Then you can easily test FFmpeg with Wine
813 (@url{}).
815 @subsection Compilation under Cygwin
817 The main issue with the 1.5.x Cygwin versions is that newlib, its C library,
818 does not contain llrint(). You need to upgrade to the unstable 1.7.x versions,
819 or leverage the implementation in MinGW (as explained below).
821 Just install your Cygwin with all the "Base" packages, plus the
822 following "Devel" ones:
823 @example
824 binutils, gcc-core, make, subversion, mingw-runtime, diffutils
825 @end example
827 The experimental gcc4 package is still buggy, hence please
828 use the official gcc 3.4.4 or a 4.2.x compiled from source by yourself.
830 Install the current binutils-20080624-2 as they work fine (the old
831 binutils-20060709-1 proved buggy on shared builds).
833 Then create a small library that just contains llrint():
835 @example
836 ar x /usr/lib/mingw/libmingwex.a llrint.o
837 ar cq /usr/local/lib/libllrint.a llrint.o
838 @end example
840 Then run
842 @example
843 ./configure --enable-static --disable-shared --extra-ldflags='-L /usr/local/lib' --extra-libs='-l llrint'
844 @end example
846 to make a static build or
848 @example
849 ./configure --enable-shared --disable-static --extra-ldflags='-L /usr/local/lib' --extra-libs='-l llrint'
850 @end example
852 to build shared libraries.
854 If you want to build FFmpeg with additional libraries, download Cygwin
855 "Devel" packages for Ogg and Vorbis from any Cygwin packages repository:
856 @example
857 libogg-devel, libvorbis-devel
858 @end example
860 These library packages are only available from Cygwin Ports
861 (@url{}) :
863 @example
864 yasm, libSDL-devel, libdirac-devel, libfaac-devel, libfaad-devel, libgsm-devel,
865 libmp3lame-devel, libschroedinger1.0-devel, speex-devel, libtheora-devel,
866 libxvidcore-devel
867 @end example
869 The recommendation for libnut and x264 is to build them from source by
870 yourself, as they evolve too quickly for Cygwin Ports to be up to date.
872 Cygwin 1.7.x has IPv6 support. You can add IPv6 to Cygwin 1.5.x by means
873 of the @code{libgetaddrinfo-devel} package, available at Cygwin Ports.
875 @subsection Crosscompilation for Windows under Cygwin
877 With Cygwin you can create Windows binaries that do not need the cygwin1.dll.
879 Just install your Cygwin as explained before, plus these additional
880 "Devel" packages:
881 @example
882 gcc-mingw-core, mingw-runtime, mingw-zlib
883 @end example
885 and add some special flags to your configure invocation.
887 For a static build run
888 @example
889 ./configure --target-os=mingw32 --enable-memalign-hack --enable-static --disable-shared --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
890 @end example
892 and for a build with shared libraries
893 @example
894 ./configure --target-os=mingw32 --enable-memalign-hack --enable-shared --disable-static --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
895 @end example
897 @section BeOS
899 BeOS support is broken in mysterious ways.
901 @section OS/2
903 For information about compiling FFmpeg on OS/2 see
904 @url{}.
906 @chapter Developers Guide
908 @section API
909 @itemize @bullet
910 @item libavcodec is the library containing the codecs (both encoding and
911 decoding). Look at @file{libavcodec/apiexample.c} to see how to use it.
913 @item libavformat is the library containing the file format handling (mux and
914 demux code for several formats). Look at @file{ffplay.c} to use it in a
915 player. See @file{output_example.c} to use it to generate audio or video
916 streams.
918 @end itemize
920 @section Integrating libavcodec or libavformat in your program
922 You can integrate all the source code of the libraries to link them
923 statically to avoid any version problem. All you need is to provide a
924 'config.mak' and a 'config.h' in the parent directory. See the defines
925 generated by ./configure to understand what is needed.
927 You can use libavcodec or libavformat in your commercial program, but
928 @emph{any patch you make must be published}. The best way to proceed is
929 to send your patches to the FFmpeg mailing list.
931 @node Coding Rules
932 @section Coding Rules
934 FFmpeg is programmed in the ISO C90 language with a few additional
935 features from ISO C99, namely:
936 @itemize @bullet
937 @item
938 the @samp{inline} keyword;
939 @item
940 @samp{//} comments;
941 @item
942 designated struct initializers (@samp{struct s x = @{ .i = 17 @};})
943 @item
944 compound literals (@samp{x = (struct s) @{ 17, 23 @};})
945 @end itemize
947 These features are supported by all compilers we care about, so we will not
948 accept patches to remove their use unless they absolutely do not impair
949 clarity and performance.
951 All code must compile with GCC 2.95 and GCC 3.3. Currently, FFmpeg also
952 compiles with several other compilers, such as the Compaq ccc compiler
953 or Sun Studio 9, and we would like to keep it that way unless it would
954 be exceedingly involved. To ensure compatibility, please do not use any
955 additional C99 features or GCC extensions. Especially watch out for:
956 @itemize @bullet
957 @item
958 mixing statements and declarations;
959 @item
960 @samp{long long} (use @samp{int64_t} instead);
961 @item
962 @samp{__attribute__} not protected by @samp{#ifdef __GNUC__} or similar;
963 @item
964 GCC statement expressions (@samp{(x = (@{ int y = 4; y; @})}).
965 @end itemize
967 Indent size is 4.
968 The presentation is the one specified by 'indent -i4 -kr -nut'.
969 The TAB character is forbidden outside of Makefiles as is any
970 form of trailing whitespace. Commits containing either will be
971 rejected by the Subversion repository.
973 The main priority in FFmpeg is simplicity and small code size in order to
974 minimize the bug count.
976 Comments: Use the JavaDoc/Doxygen
977 format (see examples below) so that code documentation
978 can be generated automatically. All nontrivial functions should have a comment
979 above them explaining what the function does, even if it is just one sentence.
980 All structures and their member variables should be documented, too.
981 @example
982 /**
983 * @@file mpeg.c
984 * MPEG codec.
985 * @@author ...
986 */
988 /**
989 * Summary sentence.
990 * more text ...
991 * ...
992 */
993 typedef struct Foobar@{
994 int var1; /**< var1 description */
995 int var2; ///< var2 description
996 /** var3 description */
997 int var3;
998 @} Foobar;
1000 /**
1001 * Summary sentence.
1002 * more text ...
1003 * ...
1004 * @@param my_parameter description of my_parameter
1005 * @@return return value description
1006 */
1007 int myfunc(int my_parameter)
1008 ...
1009 @end example
1011 fprintf and printf are forbidden in libavformat and libavcodec,
1012 please use av_log() instead.
1014 Casts should be used only when necessary. Unneeded parentheses
1015 should also be avoided if they don't make the code easier to understand.
1017 @section Development Policy
1019 @enumerate
1020 @item
1021 Contributions should be licensed under the LGPL 2.1, including an
1022 "or any later version" clause, or the MIT license. GPL 2 including
1023 an "or any later version" clause is also acceptable, but LGPL is
1024 preferred.
1025 @item
1026 You must not commit code which breaks FFmpeg! (Meaning unfinished but
1027 enabled code which breaks compilation or compiles but does not work or
1028 breaks the regression tests)
1029 You can commit unfinished stuff (for testing etc), but it must be disabled
1030 (#ifdef etc) by default so it does not interfere with other developers'
1031 work.
1032 @item
1033 You do not have to over-test things. If it works for you, and you think it
1034 should work for others, then commit. If your code has problems
1035 (portability, triggers compiler bugs, unusual environment etc) they will be
1036 reported and eventually fixed.
1037 @item
1038 Do not commit unrelated changes together, split them into self-contained
1039 pieces. Also do not forget that if part B depends on part A, but A does not
1040 depend on B, then A can and should be committed first and separate from B.
1041 Keeping changes well split into self-contained parts makes reviewing and
1042 understanding them on the commit log mailing list easier. This also helps
1043 in case of debugging later on.
1044 Also if you have doubts about splitting or not splitting, do not hesitate to
1045 ask/discuss it on the developer mailing list.
1046 @item
1047 Do not change behavior of the program (renaming options etc) without
1048 first discussing it on the ffmpeg-devel mailing list. Do not remove
1049 functionality from the code. Just improve!
1051 Note: Redundant code can be removed.
1052 @item
1053 Do not commit changes to the build system (Makefiles, configure script)
1054 which change behavior, defaults etc, without asking first. The same
1055 applies to compiler warning fixes, trivial looking fixes and to code
1056 maintained by other developers. We usually have a reason for doing things
1057 the way we do. Send your changes as patches to the ffmpeg-devel mailing
1058 list, and if the code maintainers say OK, you may commit. This does not
1059 apply to files you wrote and/or maintain.
1060 @item
1061 We refuse source indentation and other cosmetic changes if they are mixed
1062 with functional changes, such commits will be rejected and removed. Every
1063 developer has his own indentation style, you should not change it. Of course
1064 if you (re)write something, you can use your own style, even though we would
1065 prefer if the indentation throughout FFmpeg was consistent (Many projects
1066 force a given indentation style - we do not.). If you really need to make
1067 indentation changes (try to avoid this), separate them strictly from real
1068 changes.
1070 NOTE: If you had to put if()@{ .. @} over a large (> 5 lines) chunk of code,
1071 then either do NOT change the indentation of the inner part within (do not
1072 move it to the right)! or do so in a separate commit
1073 @item
1074 Always fill out the commit log message. Describe in a few lines what you
1075 changed and why. You can refer to mailing list postings if you fix a
1076 particular bug. Comments such as "fixed!" or "Changed it." are unacceptable.
1077 @item
1078 If you apply a patch by someone else, include the name and email address in
1079 the log message. Since the ffmpeg-cvslog mailing list is publicly
1080 archived you should add some SPAM protection to the email address. Send an
1081 answer to ffmpeg-devel (or wherever you got the patch from) saying that
1082 you applied the patch.
1083 @item
1084 When applying patches that have been discussed (at length) on the mailing
1085 list, reference the thread in the log message.
1086 @item
1087 Do NOT commit to code actively maintained by others without permission.
1088 Send a patch to ffmpeg-devel instead. If no one answers within a reasonable
1089 timeframe (12h for build failures and security fixes, 3 days small changes,
1090 1 week for big patches) then commit your patch if you think it is OK.
1091 Also note, the maintainer can simply ask for more time to review!
1092 @item
1093 Subscribe to the ffmpeg-cvslog mailing list. The diffs of all commits
1094 are sent there and reviewed by all the other developers. Bugs and possible
1095 improvements or general questions regarding commits are discussed there. We
1096 expect you to react if problems with your code are uncovered.
1097 @item
1098 Update the documentation if you change behavior or add features. If you are
1099 unsure how best to do this, send a patch to ffmpeg-devel, the documentation
1100 maintainer(s) will review and commit your stuff.
1101 @item
1102 Try to keep important discussions and requests (also) on the public
1103 developer mailing list, so that all developers can benefit from them.
1104 @item
1105 Never write to unallocated memory, never write over the end of arrays,
1106 always check values read from some untrusted source before using them
1107 as array index or other risky things.
1108 @item
1109 Remember to check if you need to bump versions for the specific libav
1110 parts (libavutil, libavcodec, libavformat) you are changing. You need
1111 to change the version integer.
1112 Incrementing the first component means no backward compatibility to
1113 previous versions (e.g. removal of a function from the public API).
1114 Incrementing the second component means backward compatible change
1115 (e.g. addition of a function to the public API or extension of an
1116 existing data structure).
1117 Incrementing the third component means a noteworthy binary compatible
1118 change (e.g. encoder bug fix that matters for the decoder).
1119 @item
1120 Compiler warnings indicate potential bugs or code with bad style. If a type of
1121 warning always points to correct and clean code, that warning should
1122 be disabled, not the code changed.
1123 Thus the remaining warnings can either be bugs or correct code.
1124 If it is a bug, the bug has to be fixed. If it is not, the code should
1125 be changed to not generate a warning unless that causes a slowdown
1126 or obfuscates the code.
1127 @item
1128 If you add a new file, give it a proper license header. Do not copy and
1129 paste it from a random place, use an existing file as template.
1130 @end enumerate
1132 We think our rules are not too hard. If you have comments, contact us.
1134 Note, these rules are mostly borrowed from the MPlayer project.
1136 @section Submitting patches
1138 First, (@pxref{Coding Rules}) above if you did not yet.
1140 When you submit your patch, try to send a unified diff (diff '-up'
1141 option). We cannot read other diffs :-)
1143 Also please do not submit a patch which contains several unrelated changes.
1144 Split it into separate, self-contained pieces. This does not mean splitting
1145 file by file. Instead, make the patch as small as possible while still
1146 keeping it as a logical unit that contains an individual change, even
1147 if it spans multiple files. This makes reviewing your patches much easier
1148 for us and greatly increases your chances of getting your patch applied.
1150 Run the regression tests before submitting a patch so that you can
1151 verify that there are no big problems.
1153 Patches should be posted as base64 encoded attachments (or any other
1154 encoding which ensures that the patch will not be trashed during
1155 transmission) to the ffmpeg-devel mailing list, see
1156 @url{}
1158 It also helps quite a bit if you tell us what the patch does (for example
1159 'replaces lrint by lrintf'), and why (for example '*BSD isn't C99 compliant
1160 and has no lrint()')
1162 Also please if you send several patches, send each patch as a separate mail,
1163 do not attach several unrelated patches to the same mail.
1165 @section New codecs or formats checklist
1167 @enumerate
1168 @item
1169 Did you use av_cold for codec initialization and close functions?
1170 @item
1171 Did you add a long_name under NULL_IF_CONFIG_SMALL to the AVCodec or
1172 AVInputFormat/AVOutputFormat struct?
1173 @item
1174 Did you bump the minor version number in @file{avcodec.h} or
1175 @file{avformat.h}?
1176 @item
1177 Did you register it in @file{allcodecs.c} or @file{allformats.c}?
1178 @item
1179 Did you add the CodecID to @file{avcodec.h}?
1180 @item
1181 If it has a fourcc, did you add it to @file{libavformat/riff.c},
1182 even if it is only a decoder?
1183 @item
1184 Did you add a rule to compile the appropriate files in the Makefile?
1185 Remember to do this even if you're just adding a format to a file that is
1186 already being compiled by some other rule, like a raw demuxer.
1187 @item
1188 Did you add an entry to the table of supported formats or codecs in the
1189 documentation?
1190 @item
1191 Did you add an entry in the Changelog?
1192 @item
1193 If it depends on a parser or a library, did you add that dependency in
1194 configure?
1195 @item
1196 Did you "svn add" the appropriate files before commiting?
1197 @end enumerate
1199 @section patch submission checklist
1201 @enumerate
1202 @item
1203 Do the regression tests pass with the patch applied?
1204 @item
1205 Does @code{make checkheaders} pass with the patch applied?
1206 @item
1207 Is the patch a unified diff?
1208 @item
1209 Is the patch against latest FFmpeg SVN?
1210 @item
1211 Are you subscribed to ffmpeg-dev?
1212 (the list is subscribers only due to spam)
1213 @item
1214 Have you checked that the changes are minimal, so that the same cannot be
1215 achieved with a smaller patch and/or simpler final code?
1216 @item
1217 If the change is to speed critical code, did you benchmark it?
1218 @item
1219 If you did any benchmarks, did you provide them in the mail?
1220 @item
1221 Have you checked that the patch does not introduce buffer overflows or
1222 other security issues?
1223 @item
1224 Did you test your decoder or demuxer against damaged data? If no, see
1225 tools/trasher and the noise bitstream filter. Your decoder or demuxer
1226 should not crash or end in a (near) infinite loop when fed damaged data.
1227 @item
1228 Is the patch created from the root of the source tree, so it can be
1229 applied with @code{patch -p0}?
1230 @item
1231 Does the patch not mix functional and cosmetic changes?
1232 @item
1233 Did you add tabs or trailing whitespace to the code? Both are forbidden.
1234 @item
1235 Is the patch attached to the email you send?
1236 @item
1237 Is the mime type of the patch correct? It should be text/x-diff or
1238 text/x-patch or at least text/plain and not application/octet-stream.
1239 @item
1240 If the patch fixes a bug, did you provide a verbose analysis of the bug?
1241 @item
1242 If the patch fixes a bug, did you provide enough information, including
1243 a sample, so the bug can be reproduced and the fix can be verified?
1244 Note please do not attach samples >100k to mails but rather provide a
1245 URL, you can upload to
1246 @item
1247 Did you provide a verbose summary about what the patch does change?
1248 @item
1249 Did you provide a verbose explanation why it changes things like it does?
1250 @item
1251 Did you provide a verbose summary of the user visible advantages and
1252 disadvantages if the patch is applied?
1253 @item
1254 Did you provide an example so we can verify the new feature added by the
1255 patch easily?
1256 @item
1257 If you added a new file, did you insert a license header? It should be
1258 taken from FFmpeg, not randomly copied and pasted from somewhere else.
1259 @item
1260 You should maintain alphabetical order in alphabetically ordered lists as
1261 long as doing so does not break API/ABI compatibility.
1262 @item
1263 Lines with similar content should be aligned vertically when doing so
1264 improves readability.
1265 @item
1266 Did you provide a suggestion for a clear commit log message?
1267 @end enumerate
1269 @section Patch review process
1271 All patches posted to ffmpeg-devel will be reviewed, unless they contain a
1272 clear note that the patch is not for SVN.
1273 Reviews and comments will be posted as replies to the patch on the
1274 mailing list. The patch submitter then has to take care of every comment,
1275 that can be by resubmitting a changed patch or by discussion. Resubmitted
1276 patches will themselves be reviewed like any other patch. If at some point
1277 a patch passes review with no comments then it is approved, that can for
1278 simple and small patches happen immediately while large patches will generally
1279 have to be changed and reviewed many times before they are approved.
1280 After a patch is approved it will be committed to the repository.
1282 We will review all submitted patches, but sometimes we are quite busy so
1283 especially for large patches this can take several weeks.
1285 When resubmitting patches, please do not make any significant changes
1286 not related to the comments received during review. Such patches will
1287 be rejected. Instead, submit significant changes or new features as
1288 separate patches.
1290 @section Regression tests
1292 Before submitting a patch (or committing to the repository), you should at least
1293 test that you did not break anything.
1295 The regression tests build a synthetic video stream and a synthetic
1296 audio stream. These are then encoded and decoded with all codecs or
1297 formats. The CRC (or MD5) of each generated file is recorded in a
1298 result file. A 'diff' is launched to compare the reference results and
1299 the result file.
1301 The regression tests then go on to test the FFserver code with a
1302 limited set of streams. It is important that this step runs correctly
1303 as well.
1305 Run 'make test' to test all the codecs and formats.
1307 Run 'make fulltest' to test all the codecs, formats and FFserver.
1309 [Of course, some patches may change the results of the regression tests. In
1310 this case, the reference results of the regression tests shall be modified
1311 accordingly].
1313 @bye