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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{http://www.penguin.cz/~utx/amr} 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
112 @item MP3 @tab X @tab
113 @item MPEG audio @tab X @tab X
114 @item MPEG-1 System @tab X @tab X
115 @tab muxed audio and video, VCD format supported
116 @item MPEG-PS (program stream) @tab X @tab X
117 @tab also known as @code{VOB} file, SVCD and DVD format supported
118 @item MPEG-TS (transport stream) @tab X @tab X
119 @tab also known as DVB Transport Stream
120 @item MPEG-4 @tab X @tab X
121 @tab MPEG-4 is a variant of QuickTime.
122 @item MIME multipart JPEG @tab X @tab
123 @item MSN TCP webcam @tab @tab X
124 @tab Used by MSN Messenger webcam streams.
125 @item MTV @tab @tab X
126 @item Musepack @tab @tab X
127 @item Musepack SV8 @tab @tab X
128 @item Material eXchange Format (MXF) @tab X @tab X
129 @tab SMPTE 377M, used by D-Cinema, broadcast industry.
130 @item Material eXchange Format (MXF), D-10 Mapping @tab X @tab X
131 @tab SMPTE 386M, D-10/IMX Mapping.
132 @item NC camera feed @tab @tab X
133 @tab NC (AVIP NC4600) camera streams
134 @item Nullsoft Streaming Video @tab @tab X
135 @item NuppelVideo @tab @tab X
136 @item NUT @tab X @tab X
137 @tab NUT Open Container Format
138 @item Ogg @tab X @tab X
139 @item TechnoTrend PVA @tab @tab X
140 @tab Used by TechnoTrend DVB PCI boards.
141 @item raw ADTS (AAC) @tab X @tab X
142 @item raw AC-3 @tab X @tab X
143 @item raw Chinese AVS video @tab @tab X
144 @item raw CRI ADX @tab X @tab X
145 @item raw Dirac @tab X @tab X
146 @item raw DNxHD @tab X @tab X
147 @item raw DTS @tab X @tab X
148 @item raw E-AC-3 @tab X @tab X
149 @item raw FLAC @tab X @tab X
150 @item raw GSM @tab @tab X
151 @item raw H.261 @tab X @tab X
152 @item raw H.263 @tab X @tab X
153 @item raw H.264 @tab X @tab X
154 @item raw Ingenient MJPEG @tab @tab X
155 @item raw MJPEG @tab X @tab X
156 @item raw MLP @tab @tab X
157 @item raw MPEG @tab @tab X
158 @item raw MPEG-1 @tab @tab X
159 @item raw MPEG-2 @tab @tab X
160 @item raw MPEG-4 @tab X @tab X
161 @item raw NULL @tab X @tab
162 @item raw video @tab X @tab X
163 @item raw id RoQ @tab X @tab
164 @item raw Shorten @tab @tab X
165 @item raw VC-1 @tab @tab X
166 @item raw PCM A-law @tab X @tab X
167 @item raw PCM mu-law @tab X @tab X
168 @item raw PCM signed 8 bit @tab X @tab X
169 @item raw PCM signed 16 bit big-endian @tab X @tab X
170 @item raw PCM signed 16 bit little-endian @tab X @tab X
171 @item raw PCM signed 24 bit big-endian @tab X @tab X
172 @item raw PCM signed 24 bit little-endian @tab X @tab X
173 @item raw PCM signed 32 bit big-endian @tab X @tab X
174 @item raw PCM signed 32 bit little-endian @tab X @tab X
175 @item raw PCM unsigned 8 bit @tab X @tab X
176 @item raw PCM unsigned 16 bit big-endian @tab X @tab X
177 @item raw PCM unsigned 16 bit little-endian @tab X @tab X
178 @item raw PCM unsigned 24 bit big-endian @tab X @tab X
179 @item raw PCM unsigned 24 bit little-endian @tab X @tab X
180 @item raw PCM unsigned 32 bit big-endian @tab X @tab X
181 @item raw PCM unsigned 32 bit little-endian @tab X @tab X
182 @item raw PCM floating-point 32 bit big-endian @tab X @tab X
183 @item raw PCM floating-point 32 bit little-endian @tab X @tab X
184 @item raw PCM floating-point 64 bit big-endian @tab X @tab X
185 @item raw PCM floating-point 64 bit little-endian @tab X @tab X
186 @item RDT @tab @tab X
187 @item REDCODE R3D @tab @tab X
188 @tab File format used by RED Digital cameras, contains JPEG 2000 frames and PCM audio.
189 @item RealMedia @tab X @tab X
190 @item Redirector @tab @tab X
191 @item Renderware TeXture Dictionary @tab @tab X
192 @item RL2 @tab @tab X
193 @tab Audio and video format used in some games by Entertainment Software Partners.
194 @item RPL/ARMovie @tab @tab X
195 @item RTP @tab @tab X
196 @item RTSP @tab @tab X
197 @item SDP @tab @tab X
198 @item Sega FILM/CPK @tab @tab X
199 @tab Used in many Sega Saturn console games.
200 @item Sierra SOL @tab @tab X
201 @tab .sol files used in Sierra Online games.
202 @item Sierra VMD @tab @tab X
203 @tab Used in Sierra CD-ROM games.
204 @item Smacker @tab @tab X
205 @tab Multimedia format used by many games.
206 @item Sony OpenMG (OMA) @tab @tab X
207 @tab Audio format used in Sony Sonic Stage and Sony Vegas.
208 @item Sony PlayStation STR @tab @tab X
209 @item SUN AU format @tab X @tab X
210 @item THP @tab @tab X
211 @tab Used on the Nintendo GameCube.
212 @item Tiertex Limited SEQ @tab @tab X
213 @tab Tiertex .seq files used in the DOS CD-ROM version of the game Flashback.
214 @item True Audio @tab @tab X
215 @item VC-1 test bitstream @tab X @tab X
216 @item WAV @tab X @tab X
217 @item WavPack @tab @tab X
218 @item Wing Commander III movie @tab @tab X
219 @tab Multimedia format used in Origin's Wing Commander III computer game.
220 @item Westwood Studios audio @tab @tab X
221 @tab Multimedia format used in Westwood Studios games.
222 @item Westwood Studios VQA @tab @tab X
223 @tab Multimedia format used in Westwood Studios games.
224 @item YUV4MPEG pipe @tab X @tab X
225 @end multitable
227 @code{X} means that encoding (resp. decoding) is supported.
229 @section Image Formats
231 FFmpeg can read and write images for each frame of a video sequence. The
232 following image formats are supported:
234 @multitable @columnfractions .4 .1 .1 .4
235 @item Name @tab Encoding @tab Decoding @tab Comments
236 @item .Y.U.V @tab X @tab X
237 @tab one raw file per component
238 @item animated GIF @tab X @tab X
239 @tab Only uncompressed GIFs are generated.
240 @item BMP @tab X @tab X
241 @tab Microsoft BMP image
242 @item JPEG @tab X @tab X
243 @tab Progressive JPEG is not supported.
244 @item JPEG 2000 @tab @tab E
245 @tab decoding supported through external library libopenjpeg
246 @item JPEG-LS @tab X @tab X
247 @item LJPEG @tab X @tab
248 @tab Lossless JPEG
249 @item PAM @tab X @tab X
250 @tab PAM is a PNM extension with alpha support.
251 @item PBM @tab X @tab X
252 @tab Portable BitMap image
253 @item PCX @tab @tab X
254 @tab PC Paintbrush
255 @item PGM @tab X @tab X
256 @tab Portable GrayMap image
257 @item PGMYUV @tab X @tab X
258 @tab PGM with U and V components in YUV 4:2:0
259 @item PNG @tab X @tab X
260 @tab 2/4 bpp not supported yet
261 @item PPM @tab X @tab X
262 @tab Portable PixelMap image
263 @item PTX @tab @tab X
264 @tab V.Flash PTX format
265 @item RAS @tab @tab X
266 @tab Sun Rasterfile
267 @item SGI @tab X @tab X
268 @tab SGI RGB image format
269 @item Targa @tab X @tab X
270 @tab Targa (.TGA) image format
271 @item TIFF @tab X @tab X
272 @tab YUV, JPEG and some extension is not supported yet.
273 @end multitable
275 @code{X} means that encoding (resp. decoding) is supported.
277 @code{E} means that support is provided through an external library.
279 @section Video Codecs
281 @multitable @columnfractions .4 .1 .1 .4
282 @item Name @tab Encoding @tab Decoding @tab Comments
283 @item 4X Video @tab @tab X
284 @tab Used in certain computer games.
285 @item American Laser Games MM @tab @tab X
286 @tab Used in games like Mad Dog McCree.
287 @item AMV @tab @tab X
288 @tab Used in Chinese MP3 players.
289 @item Apple Animation @tab X @tab X
290 @tab fourcc: 'rle '
291 @item Apple Graphics @tab @tab X
292 @tab fourcc: 'smc '
293 @item Apple MJPEG-B @tab @tab X
294 @item Apple QuickDraw @tab @tab X
295 @tab fourcc: qdrw
296 @item Apple Video @tab @tab X
297 @tab fourcc: rpza
298 @item Asus v1 @tab X @tab X
299 @tab fourcc: ASV1
300 @item Asus v2 @tab X @tab X
301 @tab fourcc: ASV2
302 @item ATI VCR1 @tab @tab X
303 @tab fourcc: VCR1
304 @item ATI VCR2 @tab @tab X
305 @tab fourcc: VCR2
306 @item Autodesk RLE @tab @tab X
307 @tab fourcc: AASC
308 @item AVID DNxHD @tab X @tab X
309 @tab aka SMPTE VC3
310 @item AVS video @tab @tab X
311 @tab Video encoding used by the Creature Shock game.
312 @item Bethsoft VID @tab @tab X
313 @tab Used in some games from Bethesda Softworks.
314 @item C93 video @tab @tab X
315 @tab Codec used in Cyberia game.
316 @item CamStudio @tab @tab X
317 @tab fourcc: CSCD
318 @item Cin video @tab @tab X
319 @tab Codec used in Delphine Software games.
320 @item Cinepak @tab @tab X
321 @item Cirrus Logic AccuPak @tab @tab X
322 @tab fourcc: CLJR
323 @item Creative YUV @tab @tab X
324 @tab fourcc: CYUV
325 @item Dirac @tab E @tab E
326 @tab supported through external libdirac/libschroedinger libraries
327 @item Duck TrueMotion v1 @tab @tab X
328 @tab fourcc: DUCK
329 @item Duck TrueMotion v2 @tab @tab X
330 @tab fourcc: TM20
331 @item DV @tab X @tab X
332 @item DXA Video @tab @tab X
333 @tab Codec originally used in Feeble Files game.
334 @item Electronic Arts CMV @tab @tab X
335 @tab Used in NHL 95 game.
336 @item Electronic Arts TGV @tab @tab X
337 @item Electronic Arts TGQ @tab @tab X
338 @item Electronic Arts TQI @tab @tab X
339 @item FFmpeg Video 1 @tab X @tab X
340 @tab experimental lossless codec (fourcc: FFV1)
341 @item Flash Screen Video @tab X @tab X
342 @tab fourcc: FSV1
343 @item FLIC video @tab @tab X
344 @item FLV @tab X @tab X
345 @tab Sorenson H.263 used in Flash
346 @item Fraps FPS1 @tab @tab X
347 @item H.261 @tab X @tab X
348 @item H.263(+) @tab X @tab X
349 @tab also known as RealVideo 1.0
350 @item H.264 @tab E @tab X
351 @tab encoding supported through external library libx264
352 @item HuffYUV @tab X @tab X
353 @item IBM Ultimotion @tab @tab X
354 @tab fourcc: ULTI
355 @item id Cinematic video @tab @tab X
356 @tab Used in Quake II.
357 @item id RoQ @tab X @tab X
358 @tab Used in Quake III, Jedi Knight 2, other computer games.
359 @item Intel Indeo 3 @tab @tab X
360 @item Interplay Video @tab @tab X
361 @tab Used in Interplay .MVE files.
362 @item JPEG-LS @tab X @tab X
363 @tab fourcc: MJLS, lossless and near-lossless is supported.
364 @item KMVC @tab @tab X
365 @tab Codec used in Worms games.
366 @item LOCO @tab @tab X
367 @item lossless MJPEG @tab X @tab X
368 @item Microsoft RLE @tab @tab X
369 @item Microsoft Video-1 @tab @tab X
370 @item Mimic @tab @tab X
371 @tab Used in MSN Messenger Webcam streams.
372 @item Miro VideoXL @tab @tab X
373 @tab fourcc: VIXL
374 @item MJPEG @tab X @tab X
375 @item Motion Pixels Video @tab @tab X
376 @item MPEG-1 @tab X @tab X
377 @item MPEG-2 @tab X @tab X
378 @item MPEG-4 @tab X @tab X
379 @item MSMPEG4 V1 @tab X @tab X
380 @item MSMPEG4 V2 @tab X @tab X
381 @item MSMPEG4 V3 @tab X @tab X
382 @item MSZH @tab @tab X
383 @tab Part of LCL
384 @item On2 VP3 @tab @tab X
385 @tab still experimental
386 @item On2 VP5 @tab @tab X
387 @tab fourcc: VP50
388 @item On2 VP6 @tab @tab X
389 @tab fourcc: VP60,VP61,VP62
390 @item planar RGB @tab @tab X
391 @tab fourcc: 8BPS
392 @item QPEG @tab @tab X
393 @tab fourccs: QPEG, Q1.0, Q1.1
394 @item RealVideo 1.0 @tab X @tab X
395 @item RealVideo 2.0 @tab X @tab X
396 @item RealVideo 3.0 @tab @tab X
397 @tab still far from ideal
398 @item RealVideo 4.0 @tab @tab X
399 @item Renderware TXD @tab @tab X
400 @tab Texture dictionaries used by the Renderware Engine.
401 @item RTjpeg @tab @tab X
402 @tab Video encoding used in NuppelVideo files.
403 @item Smacker video @tab @tab X
404 @tab Video encoding used in Smacker.
405 @item Snow @tab X @tab X
406 @tab experimental wavelet codec (fourcc: SNOW)
407 @item Sony PlayStation MDEC @tab @tab X
408 @item Sorenson Video 1 @tab X @tab X
409 @tab fourcc: SVQ1
410 @item Sorenson Video 3 @tab @tab X
411 @tab fourcc: SVQ3
412 @item Sunplus MJPEG @tab @tab X
413 @tab fourcc: SP5X
414 @item TechSmith Camtasia @tab @tab X
415 @tab fourcc: TSCC
416 @item Theora @tab E @tab X
417 @tab encoding supported through external library libtheora
418 @item THP @tab @tab X
419 @tab Used on the Nintendo GameCube.
420 @item Tiertex Seq video @tab @tab X
421 @tab Codec used in DOS CD-ROM FlashBack game.
422 @item VC-1 @tab @tab X
423 @item VMD Video @tab @tab X
424 @tab Used in Sierra VMD files.
425 @item VMware Video @tab @tab X
426 @tab Codec used in videos captured by VMware.
427 @item Westwood VQA @tab @tab X
428 @item Winnov WNV1 @tab @tab X
429 @item WMV7 @tab X @tab X
430 @item WMV8 @tab X @tab X
431 @item WMV9 @tab @tab X
432 @tab not completely working
433 @item Xan/WC3 @tab @tab X
434 @tab Used in Wing Commander III .MVE files.
435 @item YAMAHA SMAF @tab X @tab X
436 @item ZLIB @tab X @tab X
437 @tab part of LCL, encoder experimental
438 @item ZMBV @tab X @tab X
439 @tab Encoder works only in PAL8.
440 @end multitable
442 @code{X} means that encoding (resp. decoding) is supported.
444 @code{E} means that support is provided through an external library.
446 @section Audio Codecs
448 @multitable @columnfractions .4 .1 .1 .4
449 @item Name @tab Encoding @tab Decoding @tab Comments
450 @item 4X IMA ADPCM @tab @tab X
451 @item 8SVX audio @tab @tab X
452 @item AAC @tab E @tab X
453 @tab encoding supported through external library libfaac
454 @item AC-3 @tab IX @tab IX
455 @item AMR-NB @tab E @tab E
456 @tab supported through external library libamrnb
457 @item AMR-WB @tab E @tab E
458 @tab supported through external library libamrwb
459 @item AMV IMA ADPCM @tab @tab X
460 @tab Used in AMV files
461 @item Apple lossless audio @tab X @tab X
462 @tab QuickTime fourcc 'alac'
463 @item Apple MACE 3 @tab @tab X
464 @item Apple MACE 6 @tab @tab X
465 @item ATRAC 3 @tab @tab X
466 @item CD-ROM XA ADPCM @tab @tab X
467 @item Cin audio @tab @tab X
468 @tab Codec used in Delphine Software International games.
469 @item Creative ADPCM @tab @tab X
470 @tab 16 -> 4, 8 -> 4, 8 -> 3, 8 -> 2
471 @item CRI ADX ADPCM @tab X @tab X
472 @tab Used in Sega Dreamcast games.
473 @item DSP Group TrueSpeech @tab @tab X
474 @item DTS Coherent Audio @tab @tab X
475 @item Duck DK3 IMA ADPCM @tab @tab X
476 @tab Used in some Sega Saturn console games.
477 @item Duck DK4 IMA ADPCM @tab @tab X
478 @tab Used in some Sega Saturn console games.
479 @item DV audio @tab @tab X
480 @item Electronic Arts ADPCM @tab @tab X
481 @tab Used in various EA titles.
482 @item Enhanced AC-3 @tab @tab X
483 @item FLAC lossless audio @tab IX @tab X
484 @item G.726 ADPCM @tab X @tab X
485 @item GSM @tab E @tab E
486 @tab supported through external library libgsm
487 @item GSM_MS @tab E @tab E
488 @tab supported through external library libgsm
489 @item id RoQ DPCM @tab X @tab X
490 @tab Used in Quake III, Jedi Knight 2, other computer games.
491 @item Intel Music Coder @tab @tab X
492 @item Interplay MVE DPCM @tab @tab X
493 @tab Used in various Interplay computer games.
494 @item ISS IMA ADPCM @tab @tab X
495 @tab Used in FunCom games.
496 @item MAXIS EA ADPCM @tab @tab X
497 @tab Used in Sim City 3000.
498 @item Microsoft ADPCM @tab X @tab X
499 @item MLP/TrueHD @tab @tab X
500 @tab Used in DVD-Audio and Blu-Ray discs.
501 @item Monkey's Audio @tab @tab X
502 @tab Only versions 3.97-3.99 are supported.
503 @item MPEG audio layer 3 @tab E @tab IX
504 @tab encoding supported through external library LAME
505 @item MPEG audio layer 2 @tab IX @tab IX
506 @item MS IMA ADPCM @tab X @tab X
507 @item Musepack @tab @tab X
508 @tab SV7 and SV8 are supported.
509 @item Nellymoser ASAO @tab X @tab X
510 @item QCELP / PureVoice @tab @tab X
511 @item Qdesign QDM2 @tab @tab X
512 @tab There are still some distortions.
513 @item QT IMA ADPCM @tab X @tab X
514 @item RA144 @tab @tab X
515 @tab Real 14400 bit/s codec
516 @item RA288 @tab @tab X
517 @tab Real 28800 bit/s codec
518 @item RADnet @tab IX @tab IX
519 @tab Real low bitrate AC-3 codec
520 @item Real COOK @tab @tab X
521 @tab All versions except 5.1 are supported.
522 @item Shorten @tab @tab X
523 @item Sierra Online DPCM @tab @tab X
524 @tab Used in Sierra Online game audio files.
525 @item Smacker audio @tab @tab X
526 @item SMJPEG IMA ADPCM @tab @tab X
527 @tab Used in certain Loki game ports.
528 @item Sonic @tab X @tab X
529 @tab experimental codec
530 @item Sonic lossless @tab X @tab X
531 @tab experimental codec
532 @item Speex @tab @tab E
533 @tab supported through external library libspeex
534 @item THP ADPCM @tab @tab X
535 @tab Used on the Nintendo GameCube.
536 @item True Audio (TTA) @tab @tab X
537 @item Vorbis @tab X @tab X
538 @item WavPack @tab @tab X
539 @item Westwood Studios IMA ADPCM @tab @tab X
540 @tab Used in Westwood Studios games like Command and Conquer.
541 @item WMA v1/v2 @tab X @tab X
542 @item Xan DPCM @tab @tab X
543 @tab Used in Origin's Wing Commander IV AVI files.
544 @end multitable
546 @code{X} means that encoding (resp. decoding) is supported.
548 @code{E} means that support is provided through an external library.
550 @code{I} means that an integer-only version is available, too (ensures high
551 performance on systems without hardware floating point support).
553 @section Subtitle Formats
555 @multitable @columnfractions .4 .1 .1 .1 .1 .1
556 @item Name @tab Muxing @tab Demuxing @tab Encoding @tab Decoding
557 @item SSA/ASS @tab X @tab X
558 @item DVB @tab X @tab X @tab X @tab X
559 @item DVD @tab X @tab X @tab X @tab X
560 @item XSUB @tab @tab @tab @tab X
561 @end multitable
563 @code{X} means that the feature is supported.
565 @section Network Protocols
567 @multitable @columnfractions .4 .1 .1 .1 .1 .1
568 @item Name @tab Support
569 @item file @tab X
570 @item Gopher @tab X
571 @item HTTP @tab X
572 @item pipe @tab X
573 @item RTP @tab X
574 @item TCP @tab X
575 @item UDP @tab X
576 @end multitable
578 @code{X} means that the protocol is supported.
581 @chapter Platform Specific information
583 @section BSD
585 BSD make will not build FFmpeg, you need to install and use GNU Make
586 (@file{gmake}).
588 @section Windows
590 To get help and instructions for building FFmpeg under Windows, check out
591 the FFmpeg Windows Help Forum at
592 @url{http://ffmpeg.arrozcru.org/}.
594 @subsection Native Windows compilation
596 FFmpeg can be built to run natively on Windows using the MinGW tools. Install
597 the latest versions of MSYS and MinGW from @url{http://www.mingw.org/}.
598 You can find detailed installation
599 instructions in the download section and the FAQ.
601 FFmpeg does not build out-of-the-box with the packages the automated MinGW
602 installer provides. It also requires coreutils to be installed and many other
603 packages updated to the latest version. The minimum version for some packages
604 are listed below:
606 @itemize
607 @item bash 3.1
608 @item msys-make 3.81-2 (note: not mingw32-make)
609 @item w32api 3.13
610 @item mingw-runtime 3.15
611 @end itemize
613 You will also need to pass @code{-fno-common} to the compiler to work around
614 a GCC bug (see @url{http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37216}).
616 Within the MSYS shell, configure and make with:
618 @example
619 ./configure --enable-memalign-hack --extra-cflags=-fno-common
620 make
621 make install
622 @end example
624 This will install @file{ffmpeg.exe} along with many other development files
625 to @file{/usr/local}. You may specify another install path using the
626 @code{--prefix} option in @file{configure}.
628 Notes:
630 @itemize
632 @item In order to compile vhooks, you must have a POSIX-compliant libdl in
633 your MinGW system. Get dlfcn-win32 from
634 @url{http://code.google.com/p/dlfcn-win32}.
636 @item In order to compile FFplay, you must have the MinGW development library
637 of SDL. Get it from @url{http://www.libsdl.org}.
638 Edit the @file{bin/sdl-config} script so that it points to the correct prefix
639 where SDL was installed. Verify that @file{sdl-config} can be launched from
640 the MSYS command line.
642 @item By using @code{./configure --enable-shared} when configuring FFmpeg,
643 you can build libavutil, libavcodec and libavformat as DLLs.
645 @end itemize
647 @subsection Microsoft Visual C++ compatibility
649 As stated in the FAQ, FFmpeg will not compile under MSVC++. However, if you
650 want to use the libav* libraries in your own applications, you can still
651 compile those applications using MSVC++. But the libav* libraries you link
652 to @emph{must} be built with MinGW. However, you will not be able to debug
653 inside the libav* libraries, since MSVC++ does not recognize the debug
654 symbols generated by GCC.
655 We strongly recommend you to move over from MSVC++ to MinGW tools.
657 This description of how to use the FFmpeg libraries with MSVC++ is based on
658 Microsoft Visual C++ 2005 Express Edition. If you have a different version,
659 you might have to modify the procedures slightly.
661 @subsubsection Using static libraries
663 Assuming you have just built and installed FFmpeg in @file{/usr/local}.
665 @enumerate
667 @item Create a new console application ("File / New / Project") and then
668 select "Win32 Console Application". On the appropriate page of the
669 Application Wizard, uncheck the "Precompiled headers" option.
671 @item Write the source code for your application, or, for testing, just
672 copy the code from an existing sample application into the source file
673 that MSVC++ has already created for you. For example, you can copy
674 @file{output_example.c} from the FFmpeg distribution.
676 @item Open the "Project / Properties" dialog box. In the "Configuration"
677 combo box, select "All Configurations" so that the changes you make will
678 affect both debug and release builds. In the tree view on the left hand
679 side, select "C/C++ / General", then edit the "Additional Include
680 Directories" setting to contain the path where the FFmpeg includes were
681 installed (i.e. @file{c:\msys\1.0\local\include}).
682 Do not add MinGW's include directory here, or the include files will
683 conflict with MSVC's.
685 @item Still in the "Project / Properties" dialog box, select
686 "Linker / General" from the tree view and edit the
687 "Additional Library Directories" setting to contain the @file{lib}
688 directory where FFmpeg was installed (i.e. @file{c:\msys\1.0\local\lib}),
689 the directory where MinGW libs are installed (i.e. @file{c:\mingw\lib}),
690 and the directory where MinGW's GCC libs are installed
691 (i.e. @file{C:\mingw\lib\gcc\mingw32\4.2.1-sjlj}). Then select
692 "Linker / Input" from the tree view, and add the files @file{libavformat.a},
693 @file{libavcodec.a}, @file{libavutil.a}, @file{libmingwex.a},
694 @file{libgcc.a}, and any other libraries you used (i.e. @file{libz.a})
695 to the end of "Additional Dependencies".
697 @item Now, select "C/C++ / Code Generation" from the tree view. Select
698 "Debug" in the "Configuration" combo box. Make sure that "Runtime
699 Library" is set to "Multi-threaded Debug DLL". Then, select "Release" in
700 the "Configuration" combo box and make sure that "Runtime Library" is
701 set to "Multi-threaded DLL".
703 @item Click "OK" to close the "Project / Properties" dialog box.
705 @item MSVC++ lacks some C99 header files that are fundamental for FFmpeg.
706 Get msinttypes from @url{http://code.google.com/p/msinttypes/downloads/list}
707 and install it in MSVC++'s include directory
708 (i.e. @file{C:\Program Files\Microsoft Visual Studio 8\VC\include}).
710 @item MSVC++ also does not understand the @code{inline} keyword used by
711 FFmpeg, so you must add this line before @code{#include}ing libav*:
712 @example
713 #define inline _inline
714 @end example
716 @item Build your application, everything should work.
718 @end enumerate
720 @subsubsection Using shared libraries
722 This is how to create DLL and LIB files that are compatible with MSVC++:
724 @enumerate
726 @item Add a call to @file{vcvars32.bat} (which sets up the environment
727 variables for the Visual C++ tools) as the first line of @file{msys.bat}.
728 The standard location for @file{vcvars32.bat} is
729 @file{C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat},
730 and the standard location for @file{msys.bat} is @file{C:\msys\1.0\msys.bat}.
731 If this corresponds to your setup, add the following line as the first line
732 of @file{msys.bat}:
734 @example
735 call "C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat"
736 @end example
738 Alternatively, you may start the @file{Visual Studio 2005 Command Prompt},
739 and run @file{c:\msys\1.0\msys.bat} from there.
741 @item Within the MSYS shell, run @code{lib.exe}. If you get a help message
742 from @file{Microsoft (R) Library Manager}, this means your environment
743 variables are set up correctly, the @file{Microsoft (R) Library Manager}
744 is on the path and will be used by FFmpeg to create
745 MSVC++-compatible import libraries.
747 @item Build FFmpeg with
749 @example
750 ./configure --enable-shared --enable-memalign-hack
751 make
752 make install
753 @end example
755 Your install path (@file{/usr/local/} by default) should now have the
756 necessary DLL and LIB files under the @file{bin} directory.
758 @end enumerate
760 To use those files with MSVC++, do the same as you would do with
761 the static libraries, as described above. But in Step 4,
762 you should only need to add the directory where the LIB files are installed
763 (i.e. @file{c:\msys\usr\local\bin}). This is not a typo, the LIB files are
764 installed in the @file{bin} directory. And instead of adding @file{libxx.a}
765 files, you should add @file{avcodec.lib}, @file{avformat.lib}, and
766 @file{avutil.lib}. There should be no need for @file{libmingwex.a},
767 @file{libgcc.a}, and @file{wsock32.lib}, nor any other external library
768 statically linked into the DLLs. The @file{bin} directory contains a bunch
769 of DLL files, but the ones that are actually used to run your application
770 are the ones with a major version number in their filenames
771 (i.e. @file{avcodec-51.dll}).
773 @subsection Cross compilation for Windows with Linux
775 You must use the MinGW cross compilation tools available at
776 @url{http://www.mingw.org/}.
778 Then configure FFmpeg with the following options:
779 @example
780 ./configure --target-os=mingw32 --cross-prefix=i386-mingw32msvc-
781 @end example
782 (you can change the cross-prefix according to the prefix chosen for the
783 MinGW tools).
785 Then you can easily test FFmpeg with Wine
786 (@url{http://www.winehq.com/}).
788 @subsection Compilation under Cygwin
790 The main issue with the 1.5.x Cygwin versions is that newlib, its C library,
791 does not contain llrint(). You need to upgrade to the unstable 1.7.x versions,
792 or leverage the implementation in MinGW (as explained below).
794 Just install your Cygwin with all the "Base" packages, plus the
795 following "Devel" ones:
796 @example
797 binutils, gcc-core, make, subversion, mingw-runtime, diffutils
798 @end example
800 The experimental gcc4 package is still buggy, hence please
801 use the official gcc 3.4.4 or a 4.2.x compiled from source by yourself.
803 Install the current binutils-20080624-2 as they work fine (the old
804 binutils-20060709-1 proved buggy on shared builds).
806 Then create a small library that just contains llrint():
808 @example
809 ar x /usr/lib/mingw/libmingwex.a llrint.o
810 ar cq /usr/local/lib/libllrint.a llrint.o
811 @end example
813 Then run
815 @example
816 ./configure --enable-static --disable-shared --extra-ldflags='-L /usr/local/lib' --extra-libs='-l llrint'
817 @end example
819 to make a static build or
821 @example
822 ./configure --enable-shared --disable-static --extra-ldflags='-L /usr/local/lib' --extra-libs='-l llrint'
823 @end example
825 to build shared libraries.
827 If you want to build FFmpeg with additional libraries, download Cygwin
828 "Devel" packages for Ogg and Vorbis from any Cygwin packages repository:
829 @example
830 libogg-devel, libvorbis-devel
831 @end example
833 These library packages are only available from Cygwin Ports
834 (@url{http://sourceware.org/cygwinports/}) :
836 @example
837 yasm, libSDL-devel, libdirac-devel, libfaac-devel, libfaad-devel, libgsm-devel,
838 libmp3lame-devel, libschroedinger1.0-devel, speex-devel, libtheora-devel,
839 libxvidcore-devel
840 @end example
842 The recommendation for libnut and x264 is to build them from source by
843 yourself, as they evolve too quickly for Cygwin Ports to be up to date.
845 Cygwin 1.7.x has IPv6 support. You can add IPv6 to Cygwin 1.5.x by means
846 of the @code{libgetaddrinfo-devel} package, available at Cygwin Ports.
848 @subsection Crosscompilation for Windows under Cygwin
850 With Cygwin you can create Windows binaries that do not need the cygwin1.dll.
852 Just install your Cygwin as explained before, plus these additional
853 "Devel" packages:
854 @example
855 gcc-mingw-core, mingw-runtime, mingw-zlib
856 @end example
858 and add some special flags to your configure invocation.
860 For a static build run
861 @example
862 ./configure --target-os=mingw32 --enable-memalign-hack --enable-static --disable-shared --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
863 @end example
865 and for a build with shared libraries
866 @example
867 ./configure --target-os=mingw32 --enable-memalign-hack --enable-shared --disable-static --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
868 @end example
870 @section BeOS
872 BeOS support is broken in mysterious ways.
874 @section OS/2
876 For information about compiling FFmpeg on OS/2 see
877 @url{http://www.edm2.com/index.php/FFmpeg}.
879 @chapter Developers Guide
881 @section API
882 @itemize @bullet
883 @item libavcodec is the library containing the codecs (both encoding and
884 decoding). Look at @file{libavcodec/apiexample.c} to see how to use it.
886 @item libavformat is the library containing the file format handling (mux and
887 demux code for several formats). Look at @file{ffplay.c} to use it in a
888 player. See @file{output_example.c} to use it to generate audio or video
889 streams.
891 @end itemize
893 @section Integrating libavcodec or libavformat in your program
895 You can integrate all the source code of the libraries to link them
896 statically to avoid any version problem. All you need is to provide a
897 'config.mak' and a 'config.h' in the parent directory. See the defines
898 generated by ./configure to understand what is needed.
900 You can use libavcodec or libavformat in your commercial program, but
901 @emph{any patch you make must be published}. The best way to proceed is
902 to send your patches to the FFmpeg mailing list.
904 @node Coding Rules
905 @section Coding Rules
907 FFmpeg is programmed in the ISO C90 language with a few additional
908 features from ISO C99, namely:
909 @itemize @bullet
910 @item
911 the @samp{inline} keyword;
912 @item
913 @samp{//} comments;
914 @item
915 designated struct initializers (@samp{struct s x = @{ .i = 17 @};})
916 @item
917 compound literals (@samp{x = (struct s) @{ 17, 23 @};})
918 @end itemize
920 These features are supported by all compilers we care about, so we will not
921 accept patches to remove their use unless they absolutely do not impair
922 clarity and performance.
924 All code must compile with GCC 2.95 and GCC 3.3. Currently, FFmpeg also
925 compiles with several other compilers, such as the Compaq ccc compiler
926 or Sun Studio 9, and we would like to keep it that way unless it would
927 be exceedingly involved. To ensure compatibility, please do not use any
928 additional C99 features or GCC extensions. Especially watch out for:
929 @itemize @bullet
930 @item
931 mixing statements and declarations;
932 @item
933 @samp{long long} (use @samp{int64_t} instead);
934 @item
935 @samp{__attribute__} not protected by @samp{#ifdef __GNUC__} or similar;
936 @item
937 GCC statement expressions (@samp{(x = (@{ int y = 4; y; @})}).
938 @end itemize
940 Indent size is 4.
941 The presentation is the one specified by 'indent -i4 -kr -nut'.
942 The TAB character is forbidden outside of Makefiles as is any
943 form of trailing whitespace. Commits containing either will be
944 rejected by the Subversion repository.
946 The main priority in FFmpeg is simplicity and small code size in order to
947 minimize the bug count.
949 Comments: Use the JavaDoc/Doxygen
950 format (see examples below) so that code documentation
951 can be generated automatically. All nontrivial functions should have a comment
952 above them explaining what the function does, even if it is just one sentence.
953 All structures and their member variables should be documented, too.
954 @example
955 /**
956 * @@file mpeg.c
957 * MPEG codec.
958 * @@author ...
959 */
961 /**
962 * Summary sentence.
963 * more text ...
964 * ...
965 */
966 typedef struct Foobar@{
967 int var1; /**< var1 description */
968 int var2; ///< var2 description
969 /** var3 description */
970 int var3;
971 @} Foobar;
973 /**
974 * Summary sentence.
975 * more text ...
976 * ...
977 * @@param my_parameter description of my_parameter
978 * @@return return value description
979 */
980 int myfunc(int my_parameter)
981 ...
982 @end example
984 fprintf and printf are forbidden in libavformat and libavcodec,
985 please use av_log() instead.
987 Casts should be used only when necessary. Unneeded parentheses
988 should also be avoided if they don't make the code easier to understand.
990 @section Development Policy
992 @enumerate
993 @item
994 Contributions should be licensed under the LGPL 2.1, including an
995 "or any later version" clause, or the MIT license. GPL 2 including
996 an "or any later version" clause is also acceptable, but LGPL is
997 preferred.
998 @item
999 You must not commit code which breaks FFmpeg! (Meaning unfinished but
1000 enabled code which breaks compilation or compiles but does not work or
1001 breaks the regression tests)
1002 You can commit unfinished stuff (for testing etc), but it must be disabled
1003 (#ifdef etc) by default so it does not interfere with other developers'
1004 work.
1005 @item
1006 You do not have to over-test things. If it works for you, and you think it
1007 should work for others, then commit. If your code has problems
1008 (portability, triggers compiler bugs, unusual environment etc) they will be
1009 reported and eventually fixed.
1010 @item
1011 Do not commit unrelated changes together, split them into self-contained
1012 pieces. Also do not forget that if part B depends on part A, but A does not
1013 depend on B, then A can and should be committed first and separate from B.
1014 Keeping changes well split into self-contained parts makes reviewing and
1015 understanding them on the commit log mailing list easier. This also helps
1016 in case of debugging later on.
1017 Also if you have doubts about splitting or not splitting, do not hesitate to
1018 ask/discuss it on the developer mailing list.
1019 @item
1020 Do not change behavior of the program (renaming options etc) without
1021 first discussing it on the ffmpeg-devel mailing list. Do not remove
1022 functionality from the code. Just improve!
1024 Note: Redundant code can be removed.
1025 @item
1026 Do not commit changes to the build system (Makefiles, configure script)
1027 which change behavior, defaults etc, without asking first. The same
1028 applies to compiler warning fixes, trivial looking fixes and to code
1029 maintained by other developers. We usually have a reason for doing things
1030 the way we do. Send your changes as patches to the ffmpeg-devel mailing
1031 list, and if the code maintainers say OK, you may commit. This does not
1032 apply to files you wrote and/or maintain.
1033 @item
1034 We refuse source indentation and other cosmetic changes if they are mixed
1035 with functional changes, such commits will be rejected and removed. Every
1036 developer has his own indentation style, you should not change it. Of course
1037 if you (re)write something, you can use your own style, even though we would
1038 prefer if the indentation throughout FFmpeg was consistent (Many projects
1039 force a given indentation style - we do not.). If you really need to make
1040 indentation changes (try to avoid this), separate them strictly from real
1041 changes.
1043 NOTE: If you had to put if()@{ .. @} over a large (> 5 lines) chunk of code,
1044 then either do NOT change the indentation of the inner part within (do not
1045 move it to the right)! or do so in a separate commit
1046 @item
1047 Always fill out the commit log message. Describe in a few lines what you
1048 changed and why. You can refer to mailing list postings if you fix a
1049 particular bug. Comments such as "fixed!" or "Changed it." are unacceptable.
1050 @item
1051 If you apply a patch by someone else, include the name and email address in
1052 the log message. Since the ffmpeg-cvslog mailing list is publicly
1053 archived you should add some SPAM protection to the email address. Send an
1054 answer to ffmpeg-devel (or wherever you got the patch from) saying that
1055 you applied the patch.
1056 @item
1057 When applying patches that have been discussed (at length) on the mailing
1058 list, reference the thread in the log message.
1059 @item
1060 Do NOT commit to code actively maintained by others without permission.
1061 Send a patch to ffmpeg-devel instead. If no one answers within a reasonable
1062 timeframe (12h for build failures and security fixes, 3 days small changes,
1063 1 week for big patches) then commit your patch if you think it is OK.
1064 Also note, the maintainer can simply ask for more time to review!
1065 @item
1066 Subscribe to the ffmpeg-cvslog mailing list. The diffs of all commits
1067 are sent there and reviewed by all the other developers. Bugs and possible
1068 improvements or general questions regarding commits are discussed there. We
1069 expect you to react if problems with your code are uncovered.
1070 @item
1071 Update the documentation if you change behavior or add features. If you are
1072 unsure how best to do this, send a patch to ffmpeg-devel, the documentation
1073 maintainer(s) will review and commit your stuff.
1074 @item
1075 Try to keep important discussions and requests (also) on the public
1076 developer mailing list, so that all developers can benefit from them.
1077 @item
1078 Never write to unallocated memory, never write over the end of arrays,
1079 always check values read from some untrusted source before using them
1080 as array index or other risky things.
1081 @item
1082 Remember to check if you need to bump versions for the specific libav
1083 parts (libavutil, libavcodec, libavformat) you are changing. You need
1084 to change the version integer.
1085 Incrementing the first component means no backward compatibility to
1086 previous versions (e.g. removal of a function from the public API).
1087 Incrementing the second component means backward compatible change
1088 (e.g. addition of a function to the public API or extension of an
1089 existing data structure).
1090 Incrementing the third component means a noteworthy binary compatible
1091 change (e.g. encoder bug fix that matters for the decoder).
1092 @item
1093 Compiler warnings indicate potential bugs or code with bad style. If a type of
1094 warning always points to correct and clean code, that warning should
1095 be disabled, not the code changed.
1096 Thus the remaining warnings can either be bugs or correct code.
1097 If it is a bug, the bug has to be fixed. If it is not, the code should
1098 be changed to not generate a warning unless that causes a slowdown
1099 or obfuscates the code.
1100 @item
1101 If you add a new file, give it a proper license header. Do not copy and
1102 paste it from a random place, use an existing file as template.
1103 @end enumerate
1105 We think our rules are not too hard. If you have comments, contact us.
1107 Note, these rules are mostly borrowed from the MPlayer project.
1109 @section Submitting patches
1111 First, (@pxref{Coding Rules}) above if you did not yet.
1113 When you submit your patch, try to send a unified diff (diff '-up'
1114 option). We cannot read other diffs :-)
1116 Also please do not submit a patch which contains several unrelated changes.
1117 Split it into separate, self-contained pieces. This does not mean splitting
1118 file by file. Instead, make the patch as small as possible while still
1119 keeping it as a logical unit that contains an individual change, even
1120 if it spans multiple files. This makes reviewing your patches much easier
1121 for us and greatly increases your chances of getting your patch applied.
1123 Run the regression tests before submitting a patch so that you can
1124 verify that there are no big problems.
1126 Patches should be posted as base64 encoded attachments (or any other
1127 encoding which ensures that the patch will not be trashed during
1128 transmission) to the ffmpeg-devel mailing list, see
1129 @url{http://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel}
1131 It also helps quite a bit if you tell us what the patch does (for example
1132 'replaces lrint by lrintf'), and why (for example '*BSD isn't C99 compliant
1133 and has no lrint()')
1135 Also please if you send several patches, send each patch as a separate mail,
1136 do not attach several unrelated patches to the same mail.
1138 @section New codecs or formats checklist
1140 @enumerate
1141 @item
1142 Did you use av_cold for codec initialization and close functions?
1143 @item
1144 Did you add a long_name under NULL_IF_CONFIG_SMALL to the AVCodec or
1145 AVInputFormat/AVOutputFormat struct?
1146 @item
1147 Did you bump the minor version number in @file{avcodec.h} or
1148 @file{avformat.h}?
1149 @item
1150 Did you register it in @file{allcodecs.c} or @file{allformats.c}?
1151 @item
1152 Did you add the CodecID to @file{avcodec.h}?
1153 @item
1154 If it has a fourcc, did you add it to @file{libavformat/riff.c},
1155 even if it is only a decoder?
1156 @item
1157 Did you add a rule to compile the appropriate files in the Makefile?
1158 Remember to do this even if you're just adding a format to a file that is
1159 already being compiled by some other rule, like a raw demuxer.
1160 @item
1161 Did you add an entry to the table of supported formats or codecs in the
1162 documentation?
1163 @item
1164 Did you add an entry in the Changelog?
1165 @item
1166 If it depends on a parser or a library, did you add that dependency in
1167 configure?
1168 @item
1169 Did you "svn add" the appropriate files before commiting?
1170 @end enumerate
1172 @section patch submission checklist
1174 @enumerate
1175 @item
1176 Do the regression tests pass with the patch applied?
1177 @item
1178 Does @code{make checkheaders} pass with the patch applied?
1179 @item
1180 Is the patch a unified diff?
1181 @item
1182 Is the patch against latest FFmpeg SVN?
1183 @item
1184 Are you subscribed to ffmpeg-dev?
1185 (the list is subscribers only due to spam)
1186 @item
1187 Have you checked that the changes are minimal, so that the same cannot be
1188 achieved with a smaller patch and/or simpler final code?
1189 @item
1190 If the change is to speed critical code, did you benchmark it?
1191 @item
1192 If you did any benchmarks, did you provide them in the mail?
1193 @item
1194 Have you checked that the patch does not introduce buffer overflows or
1195 other security issues?
1196 @item
1197 Did you test your decoder or demuxer against damaged data? If no, see
1198 tools/trasher and the noise bitstream filter. Your decoder or demuxer
1199 should not crash or end in a (near) infinite loop when fed damaged data.
1200 @item
1201 Is the patch created from the root of the source tree, so it can be
1202 applied with @code{patch -p0}?
1203 @item
1204 Does the patch not mix functional and cosmetic changes?
1205 @item
1206 Did you add tabs or trailing whitespace to the code? Both are forbidden.
1207 @item
1208 Is the patch attached to the email you send?
1209 @item
1210 Is the mime type of the patch correct? It should be text/x-diff or
1211 text/x-patch or at least text/plain and not application/octet-stream.
1212 @item
1213 If the patch fixes a bug, did you provide a verbose analysis of the bug?
1214 @item
1215 If the patch fixes a bug, did you provide enough information, including
1216 a sample, so the bug can be reproduced and the fix can be verified?
1217 Note please do not attach samples >100k to mails but rather provide a
1218 URL, you can upload to ftp://upload.ffmpeg.org
1219 @item
1220 Did you provide a verbose summary about what the patch does change?
1221 @item
1222 Did you provide a verbose explanation why it changes things like it does?
1223 @item
1224 Did you provide a verbose summary of the user visible advantages and
1225 disadvantages if the patch is applied?
1226 @item
1227 Did you provide an example so we can verify the new feature added by the
1228 patch easily?
1229 @item
1230 If you added a new file, did you insert a license header? It should be
1231 taken from FFmpeg, not randomly copied and pasted from somewhere else.
1232 @item
1233 You should maintain alphabetical order in alphabetically ordered lists as
1234 long as doing so does not break API/ABI compatibility.
1235 @item
1236 Lines with similar content should be aligned vertically when doing so
1237 improves readability.
1238 @item
1239 Did you provide a suggestion for a clear commit log message?
1240 @end enumerate
1242 @section Patch review process
1244 All patches posted to ffmpeg-devel will be reviewed, unless they contain a
1245 clear note that the patch is not for SVN.
1246 Reviews and comments will be posted as replies to the patch on the
1247 mailing list. The patch submitter then has to take care of every comment,
1248 that can be by resubmitting a changed patch or by discussion. Resubmitted
1249 patches will themselves be reviewed like any other patch. If at some point
1250 a patch passes review with no comments then it is approved, that can for
1251 simple and small patches happen immediately while large patches will generally
1252 have to be changed and reviewed many times before they are approved.
1253 After a patch is approved it will be committed to the repository.
1255 We will review all submitted patches, but sometimes we are quite busy so
1256 especially for large patches this can take several weeks.
1258 When resubmitting patches, please do not make any significant changes
1259 not related to the comments received during review. Such patches will
1260 be rejected. Instead, submit significant changes or new features as
1261 separate patches.
1263 @section Regression tests
1265 Before submitting a patch (or committing to the repository), you should at least
1266 test that you did not break anything.
1268 The regression tests build a synthetic video stream and a synthetic
1269 audio stream. These are then encoded and decoded with all codecs or
1270 formats. The CRC (or MD5) of each generated file is recorded in a
1271 result file. A 'diff' is launched to compare the reference results and
1272 the result file.
1274 The regression tests then go on to test the FFserver code with a
1275 limited set of streams. It is important that this step runs correctly
1276 as well.
1278 Run 'make test' to test all the codecs and formats.
1280 Run 'make fulltest' to test all the codecs, formats and FFserver.
1282 [Of course, some patches may change the results of the regression tests. In
1283 this case, the reference results of the regression tests shall be modified
1284 accordingly].
1286 @bye