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