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 (libamr) as well as
22 the OpenCORE libraries for AMR-NB decoding/encoding and AMR-WB decoding.
26 Go to @url{http://gitorious.org/opencore-amr/} and follow the instructions for
27 installing the libraries. Then pass @code{--enable-libopencore-amrnb} and/or
28 @code{--enable-libopencore-amrwb} to configure to enable the libraries.
30 Note that OpenCORE is under the Apache License 2.0 (see
31 @url{http://www.apache.org/licenses/LICENSE-2.0} for details), which is
32 incompatible with the LGPL version 2.1 and GPL version 2. You have to
33 upgrade FFmpeg's license to LGPL version 3 (or if you have enabled
34 GPL components, GPL version 3) to use it.
38 Go to @url{http://www.penguin.cz/~utx/amr} and follow the instructions for
39 installing the libraries. Then pass @code{--enable-libamr-nb} and/or
40 @code{--enable-libamr-wb} to configure to enable the libraries.
42 Note that libamr is copyrighted without any sort of license grant. This means
43 that you can use it if you legally obtained it but you are not allowed to
44 redistribute it in any way. @strong{Any FFmpeg binaries with libamr support
45 you create are non-free and unredistributable!}
48 @chapter Supported File Formats and Codecs
50 You can use the @code{-formats} option to have an exhaustive list.
54 FFmpeg supports the following file formats through the @code{libavformat}
57 @multitable @columnfractions .4 .1 .1 .4
58 @item Name @tab Encoding @tab Decoding @tab Comments
60 @tab 4X Technologies format, used in some games.
61 @item 8088flex TMV @tab @tab X
62 @item Audio IFF (AIFF) @tab X @tab X
63 @item American Laser Games MM @tab @tab X
64 @tab Multimedia format used in games like Mad Dog McCree.
65 @item 3GPP AMR @tab X @tab X
66 @item ASF @tab X @tab X
67 @item AVI @tab X @tab X
68 @item AVISynth @tab @tab X
70 @tab Multimedia format used by the Creature Shock game.
71 @item Beam Software SIFF @tab @tab X
72 @tab Audio and video format used in some games by Beam Software.
73 @item Bethesda Softworks VID @tab @tab X
74 @tab Used in some games from Bethesda Softworks.
75 @item Brute Force & Ignorance @tab @tab X
76 @tab Used in the game Flash Traffic: City of Angels.
77 @item Interplay C93 @tab @tab X
78 @tab Used in the game Cyberia from Interplay.
79 @item Delphine Software International CIN @tab @tab X
80 @tab Multimedia format used by Delphine Software games.
81 @item CRC testing format @tab X @tab
82 @item Creative Voice @tab X @tab X
83 @tab Created for the Sound Blaster Pro.
84 @item CRYO APC @tab @tab X
85 @tab Audio format used in some games by CRYO Interactive Entertainment.
86 @item D-Cinema audio @tab X @tab X
87 @item DV video @tab X @tab X
89 @tab This format is used in the non-Windows version of the Feeble Files
90 game and different game cutscenes repacked for use with ScummVM.
91 @item Electronic Arts cdata @tab @tab X
92 @item Electronic Arts Multimedia @tab @tab X
93 @tab Used in various EA games; files have extensions like WVE and UV2.
94 @item FFM (FFserver live feed) @tab X @tab X
95 @item Flash (SWF) @tab X @tab X
96 @item Flash 9 (AVM2) @tab X @tab X
97 @tab Only embedded audio is decoded.
98 @item FLI/FLC/FLX animation @tab @tab X
100 @item Flash Video (FLV) @tab @tab X
101 @tab Macromedia Flash video files
102 @item framecrc testing format @tab X @tab
103 @item FunCom ISS @tab @tab X
104 @tab Audio format used in various games from FunCom like The Longest Journey.
105 @item GIF Animation @tab X @tab
106 @item GXF @tab X @tab X
107 @tab General eXchange Format SMPTE 360M, used by Thomson Grass Valley
109 @item id Quake II CIN video @tab @tab X
110 @item id RoQ @tab X @tab X
111 @tab Used in Quake III, Jedi Knight 2, other computer games.
112 @item IFF @tab @tab X
113 @tab Interchange File Format
114 @item Interplay MVE @tab @tab X
115 @tab Format used in various Interplay computer games.
116 @item LMLM4 @tab @tab X
117 @tab Used by Linux Media Labs MPEG-4 PCI boards
118 @item Matroska @tab X @tab X
119 @item Matroska audio @tab X @tab
120 @item MAXIS XA @tab @tab X
121 @tab Used in Sim City 3000; file extension .xa.
122 @item Monkey's Audio @tab @tab X
123 @item Motion Pixels MVI @tab @tab X
124 @item MOV/QuickTime/MP4 @tab X @tab X
125 @tab 3GP, 3GP2, PSP, iPod variants supported
126 @item MP2 @tab X @tab X
127 @item MP3 @tab X @tab X
128 @item MPEG-1 System @tab X @tab X
129 @tab muxed audio and video, VCD format supported
130 @item MPEG-PS (program stream) @tab X @tab X
131 @tab also known as @code{VOB} file, SVCD and DVD format supported
132 @item MPEG-TS (transport stream) @tab X @tab X
133 @tab also known as DVB Transport Stream
134 @item MPEG-4 @tab X @tab X
135 @tab MPEG-4 is a variant of QuickTime.
136 @item MIME multipart JPEG @tab X @tab
137 @item MSN TCP webcam @tab @tab X
138 @tab Used by MSN Messenger webcam streams.
139 @item MTV @tab @tab X
140 @item Musepack @tab @tab X
141 @item Musepack SV8 @tab @tab X
142 @item Material eXchange Format (MXF) @tab X @tab X
143 @tab SMPTE 377M, used by D-Cinema, broadcast industry.
144 @item Material eXchange Format (MXF), D-10 Mapping @tab X @tab X
145 @tab SMPTE 386M, D-10/IMX Mapping.
146 @item NC camera feed @tab @tab X
147 @tab NC (AVIP NC4600) camera streams
148 @item NTT TwinVQ (VQF) @tab @tab X
149 @tab Nippon Telegraph and Telephone Corporation TwinVQ.
150 @item Nullsoft Streaming Video @tab @tab X
151 @item NuppelVideo @tab @tab X
152 @item NUT @tab X @tab X
153 @tab NUT Open Container Format
154 @item Ogg @tab X @tab X
155 @item TechnoTrend PVA @tab @tab X
156 @tab Used by TechnoTrend DVB PCI boards.
157 @item QCP @tab @tab X
158 @item raw ADTS (AAC) @tab X @tab X
159 @item raw AC-3 @tab X @tab X
160 @item raw Chinese AVS video @tab @tab X
161 @item raw CRI ADX @tab X @tab X
162 @item raw Dirac @tab X @tab X
163 @item raw DNxHD @tab X @tab X
164 @item raw DTS @tab X @tab X
165 @item raw E-AC-3 @tab X @tab X
166 @item raw FLAC @tab X @tab X
167 @item raw GSM @tab @tab X
168 @item raw H.261 @tab X @tab X
169 @item raw H.263 @tab X @tab X
170 @item raw H.264 @tab X @tab X
171 @item raw Ingenient MJPEG @tab @tab X
172 @item raw MJPEG @tab X @tab X
173 @item raw MLP @tab @tab X
174 @item raw MPEG @tab @tab X
175 @item raw MPEG-1 @tab @tab X
176 @item raw MPEG-2 @tab @tab X
177 @item raw MPEG-4 @tab X @tab X
178 @item raw NULL @tab X @tab
179 @item raw video @tab X @tab X
180 @item raw id RoQ @tab X @tab
181 @item raw Shorten @tab @tab X
182 @item raw TrueHD @tab X @tab X
183 @item raw VC-1 @tab @tab X
184 @item raw PCM A-law @tab X @tab X
185 @item raw PCM mu-law @tab X @tab X
186 @item raw PCM signed 8 bit @tab X @tab X
187 @item raw PCM signed 16 bit big-endian @tab X @tab X
188 @item raw PCM signed 16 bit little-endian @tab X @tab X
189 @item raw PCM signed 24 bit big-endian @tab X @tab X
190 @item raw PCM signed 24 bit little-endian @tab X @tab X
191 @item raw PCM signed 32 bit big-endian @tab X @tab X
192 @item raw PCM signed 32 bit little-endian @tab X @tab X
193 @item raw PCM unsigned 8 bit @tab X @tab X
194 @item raw PCM unsigned 16 bit big-endian @tab X @tab X
195 @item raw PCM unsigned 16 bit little-endian @tab X @tab X
196 @item raw PCM unsigned 24 bit big-endian @tab X @tab X
197 @item raw PCM unsigned 24 bit little-endian @tab X @tab X
198 @item raw PCM unsigned 32 bit big-endian @tab X @tab X
199 @item raw PCM unsigned 32 bit little-endian @tab X @tab X
200 @item raw PCM floating-point 32 bit big-endian @tab X @tab X
201 @item raw PCM floating-point 32 bit little-endian @tab X @tab X
202 @item raw PCM floating-point 64 bit big-endian @tab X @tab X
203 @item raw PCM floating-point 64 bit little-endian @tab X @tab X
204 @item RDT @tab @tab X
205 @item REDCODE R3D @tab @tab X
206 @tab File format used by RED Digital cameras, contains JPEG 2000 frames and PCM audio.
207 @item RealMedia @tab X @tab X
208 @item Redirector @tab @tab X
209 @item Renderware TeXture Dictionary @tab @tab X
210 @item RL2 @tab @tab X
211 @tab Audio and video format used in some games by Entertainment Software Partners.
212 @item RPL/ARMovie @tab @tab X
213 @item RTP @tab @tab X
214 @item RTSP @tab @tab X
215 @item SDP @tab @tab X
216 @item Sega FILM/CPK @tab @tab X
217 @tab Used in many Sega Saturn console games.
218 @item Sierra SOL @tab @tab X
219 @tab .sol files used in Sierra Online games.
220 @item Sierra VMD @tab @tab X
221 @tab Used in Sierra CD-ROM games.
222 @item Smacker @tab @tab X
223 @tab Multimedia format used by many games.
224 @item Sony OpenMG (OMA) @tab @tab X
225 @tab Audio format used in Sony Sonic Stage and Sony Vegas.
226 @item Sony PlayStation STR @tab @tab X
227 @item SoX native format @tab X @tab X
228 @item SUN AU format @tab X @tab X
229 @item THP @tab @tab X
230 @tab Used on the Nintendo GameCube.
231 @item Tiertex Limited SEQ @tab @tab X
232 @tab Tiertex .seq files used in the DOS CD-ROM version of the game Flashback.
233 @item True Audio @tab @tab X
234 @item VC-1 test bitstream @tab X @tab X
235 @item WAV @tab X @tab X
236 @item WavPack @tab @tab X
237 @item Wing Commander III movie @tab @tab X
238 @tab Multimedia format used in Origin's Wing Commander III computer game.
239 @item Westwood Studios audio @tab @tab X
240 @tab Multimedia format used in Westwood Studios games.
241 @item Westwood Studios VQA @tab @tab X
242 @tab Multimedia format used in Westwood Studios games.
243 @item YUV4MPEG pipe @tab X @tab X
246 @code{X} means that encoding (resp. decoding) is supported.
248 @section Image Formats
250 FFmpeg can read and write images for each frame of a video sequence. The
251 following image formats are supported:
253 @multitable @columnfractions .4 .1 .1 .4
254 @item Name @tab Encoding @tab Decoding @tab Comments
255 @item .Y.U.V @tab X @tab X
256 @tab one raw file per component
257 @item animated GIF @tab X @tab X
258 @tab Only uncompressed GIFs are generated.
259 @item BMP @tab X @tab X
260 @tab Microsoft BMP image
261 @item DPX @tab @tab X
262 @tab Digital Picture Exchange
263 @item JPEG @tab X @tab X
264 @tab Progressive JPEG is not supported.
265 @item JPEG 2000 @tab @tab E
266 @tab decoding supported through external library libopenjpeg
267 @item JPEG-LS @tab X @tab X
268 @item LJPEG @tab X @tab
270 @item PAM @tab X @tab X
271 @tab PAM is a PNM extension with alpha support.
272 @item PBM @tab X @tab X
273 @tab Portable BitMap image
274 @item PCX @tab X @tab X
276 @item PGM @tab X @tab X
277 @tab Portable GrayMap image
278 @item PGMYUV @tab X @tab X
279 @tab PGM with U and V components in YUV 4:2:0
280 @item PNG @tab X @tab X
281 @tab 2/4 bpp not supported yet
282 @item PPM @tab X @tab X
283 @tab Portable PixelMap image
284 @item PTX @tab @tab X
285 @tab V.Flash PTX format
286 @item SGI @tab X @tab X
287 @tab SGI RGB image format
288 @item Sun Rasterfile @tab @tab X
289 @tab Sun RAS image format
290 @item TIFF @tab X @tab X
291 @tab YUV, JPEG and some extension is not supported yet.
292 @item Truevision Targa @tab X @tab X
293 @tab Targa (.TGA) image format
296 @code{X} means that encoding (resp. decoding) is supported.
298 @code{E} means that support is provided through an external library.
300 @section Video Codecs
302 @multitable @columnfractions .4 .1 .1 .4
303 @item Name @tab Encoding @tab Decoding @tab Comments
304 @item 4X Movie @tab @tab X
305 @tab Used in certain computer games.
306 @item 8088flex TMV @tab @tab X
307 @item 8SVX exponential @tab @tab X
308 @item 8SVX fibonacci @tab @tab X
309 @item American Laser Games MM @tab @tab X
310 @tab Used in games like Mad Dog McCree.
311 @item AMV Video @tab @tab X
312 @tab Used in Chinese MP3 players.
313 @item Apple MJPEG-B @tab @tab X
314 @item Apple QuickDraw @tab @tab X
316 @item Asus v1 @tab X @tab X
318 @item Asus v2 @tab X @tab X
320 @item ATI VCR1 @tab @tab X
322 @item ATI VCR2 @tab @tab X
324 @item Autodesk Animator Flic video @tab @tab X
325 @item Autodesk RLE @tab @tab X
327 @item AVS (Audio Video Standard) video @tab @tab X
328 @tab Video encoding used by the Creature Shock game.
329 @item Beam Software VB @tab @tab X
330 @item Bethesda VID video @tab @tab X
331 @tab Used in some games from Bethesda Softworks.
332 @item Brute Force & Ignorance @tab @tab X
333 @tab Used in the game Flash Traffic: City of Angels.
334 @item C93 video @tab @tab X
335 @tab Codec used in Cyberia game.
336 @item CamStudio @tab @tab X
338 @item Chinese AVS video @tab @tab X
339 @tab AVS1-P2, JiZhun profile
340 @item Delphine Software International CIN video @tab @tab X
341 @tab Codec used in Delphine Software International games.
342 @item Cinepak @tab @tab X
343 @item Cirrus Logic AccuPak @tab @tab X
345 @item Creative YUV (CYUV) @tab @tab X
346 @item Dirac @tab E @tab E
347 @tab supported through external libdirac/libschroedinger libraries
348 @item DNxHD @tab X @tab X
350 @item Duck TrueMotion 1.0 @tab @tab X
352 @item Duck TrueMotion 2.0 @tab @tab X
354 @item DV (Digital Video) @tab X @tab X
355 @item Feeble Files/ScummVM DXA @tab @tab X
356 @tab Codec originally used in Feeble Files game.
357 @item Electronic Arts CMV video @tab @tab X
358 @tab Used in NHL 95 game.
359 @item Electronic Arts TGV video @tab @tab X
360 @item Electronic Arts TGQ video @tab @tab X
361 @item Electronic Arts TQI video @tab @tab X
362 @item Escape 124 @tab @tab X
363 @item FFmpeg codec #1 @tab X @tab X
364 @tab experimental lossless codec (fourcc: FFV1)
365 @item Flash Screen Video v1 @tab X @tab X
367 @item Flash Video (FLV) @tab X @tab X
368 @tab Sorenson H.263 used in Flash
369 @item Fraps @tab @tab X
370 @item H.261 @tab X @tab X
371 @item H.263 / H.263-1996 @tab X @tab X
372 @item H.263+ / H.263-1998 / H.263 version 2 @tab X @tab X
373 @item H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10 @tab E @tab X
374 @tab encoding supported through external library libx264
375 @item H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10 (VDPAU acceleration) @tab E @tab X
376 @item HuffYUV @tab X @tab X
377 @item HuffYUV FFmpeg variant @tab X @tab X
378 @item IBM Ultimotion @tab @tab X
380 @item id Cinematic video @tab @tab X
381 @tab Used in Quake II.
382 @item id RoQ video @tab X @tab X
383 @tab Used in Quake III, Jedi Knight 2, other computer games.
384 @item Intel H.263 @tab @tab X
385 @item Intel Indeo 2 @tab @tab X
386 @item Intel Indeo 3 @tab @tab X
387 @item Interplay C93 @tab @tab X
388 @tab Used in the game Cyberia from Interplay.
389 @item Interplay MVE video @tab @tab X
390 @tab Used in Interplay .MVE files.
391 @item Karl Morton's video codec @tab @tab X
392 @tab Codec used in Worms games.
393 @item LCL (LossLess Codec Library) MSZH @tab @tab X
394 @item LCL (LossLess Codec Library) ZLIB @tab E @tab E
395 @item LOCO @tab @tab X
396 @item lossless MJPEG @tab X @tab X
397 @item Microsoft RLE @tab @tab X
398 @item Microsoft Video 1 @tab @tab X
399 @item Mimic @tab @tab X
400 @tab Used in MSN Messenger Webcam streams.
401 @item Miro VideoXL @tab @tab X
403 @item MJPEG (Motion JPEG) @tab X @tab X
404 @item Motion Pixels video @tab @tab X
405 @item MPEG-1 video @tab X @tab X
406 @item MPEG-1/2 video XvMC (X-Video Motion Compensation) @tab @tab X
407 @item MPEG-1/2 video (VDPAU acceleration) @tab @tab X
408 @item MPEG-2 video @tab X @tab X
409 @item MPEG-4 part 2 @tab X @tab X
410 @ libxvidcore can be used alternatively for encoding.
411 @item MPEG-4 part 2 Microsoft variant version 1 @tab X @tab X
412 @item MPEG-4 part 2 Microsoft variant version 2 @tab X @tab X
413 @item MPEG-4 part 2 Microsoft variant version 3 @tab X @tab X
414 @item Nintendo Gamecube THP video @tab @tab X
415 @item NuppelVideo/RTjpeg @tab @tab X
416 @tab Video encoding used in NuppelVideo files.
417 @item On2 VP3 @tab @tab X
418 @tab still experimental
419 @item On2 VP5 @tab @tab X
421 @item On2 VP6 @tab @tab X
422 @tab fourcc: VP60,VP61,VP62
423 @item planar RGB @tab @tab X
425 @item Q-team QPEG @tab @tab X
426 @tab fourccs: QPEG, Q1.0, Q1.1
427 @item QuickTime 8BPS video @tab @tab X
428 @item QuickTime Animation (RLE) video @tab X @tab X
430 @item QuickTime Graphics (SMC) @tab @tab X
432 @item QuickTime video (RPZA) @tab @tab X
434 @item Raw Video @tab X @tab X
435 @item RealVideo 1.0 @tab X @tab X
436 @item RealVideo 2.0 @tab X @tab X
437 @item RealVideo 3.0 @tab @tab X
438 @tab still far from ideal
439 @item RealVideo 4.0 @tab @tab X
440 @item Renderware TXD (TeXture Dictionary) @tab @tab X
441 @tab Texture dictionaries used by the Renderware Engine.
442 @item RL2 video @tab @tab X
443 @tab used in some games by Entertainment Software Partners
444 @item Sierra VMD video @tab @tab X
445 @tab Used in Sierra VMD files.
446 @item Smacker video @tab @tab X
447 @tab Video encoding used in Smacker.
448 @item SMPTE VC-1 @tab @tab X
449 @item Snow @tab X @tab X
450 @tab experimental wavelet codec (fourcc: SNOW)
451 @item Sony PlayStation MDEC (Motion DECoder) @tab @tab X
452 @item Sorenson Vector Quantizer 1 @tab X @tab X
454 @item Sorenson Vector Quantizer 3 @tab @tab X
456 @item Sunplus JPEG (SP5X) @tab @tab X
458 @item TechSmith Screen Capture Codec @tab @tab X
460 @item Theora @tab E @tab X
461 @tab encoding supported through external library libtheora
462 @item Tiertex Limited SEQ video @tab @tab X
463 @tab Codec used in DOS CD-ROM FlashBack game.
464 @item V210 Quicktime Uncompressed 4:2:2 10-bit @tab X @tab X
465 @item VMware Screen Codec / VMware Video @tab @tab X
466 @tab Codec used in videos captured by VMware.
467 @item Westwood Studios VQA (Vector Quantized Animation) video @tab @tab X
468 @item Windows Media Video 7 @tab X @tab X
469 @item Windows Media Video 8 @tab X @tab X
470 @item Windows Media Video 9 @tab @tab X
471 @tab not completely working
472 @item Wing Commander III / Xan @tab @tab X
473 @tab Used in Wing Commander III .MVE files.
474 @item Winnov WNV1 @tab @tab X
475 @item WMV7 @tab X @tab X
476 @item YAMAHA SMAF @tab X @tab X
477 @item ZLIB @tab X @tab X
478 @tab part of LCL, encoder experimental
479 @item Zip Motion Blocks Video @tab X @tab X
480 @tab Encoder works only in PAL8.
483 @code{X} means that encoding (resp. decoding) is supported.
485 @code{E} means that support is provided through an external library.
487 @section Audio Codecs
489 @multitable @columnfractions .4 .1 .1 .4
490 @item Name @tab Encoding @tab Decoding @tab Comments
491 @item 8SVX audio @tab @tab X
492 @item AAC @tab E @tab X
493 @tab encoding supported through external library libfaac
494 @item AC-3 @tab IX @tab X
495 @item ADPCM 4X Movie @tab @tab X
496 @item ADPCM CDROM XA @tab @tab X
497 @item ADPCM Creative Technology @tab @tab X
498 @tab 16 -> 4, 8 -> 4, 8 -> 3, 8 -> 2
499 @item ADPCM Electronic Arts @tab @tab X
500 @tab Used in various EA titles.
501 @item ADPCM Electronic Arts Maxis CDROM XS @tab @tab X
502 @tab Used in Sim City 3000.
503 @item ADPCM Electronic Arts R1 @tab @tab X
504 @item ADPCM Electronic Arts R2 @tab @tab X
505 @item ADPCM Electronic Arts R3 @tab @tab X
506 @item ADPCM Electronic Arts XAS @tab @tab X
507 @item ADPCM G.726 @tab X @tab X
508 @item ADPCM IMA AMV @tab @tab X
509 @tab Used in AMV files
510 @item ADPCM IMA Electronic Arts EACS @tab @tab X
511 @item ADPCM IMA Electronic Arts SEAD @tab @tab X
512 @item ADPCM IMA Funcom @tab @tab X
513 @item ADPCM IMA QuickTime @tab X @tab X
514 @item ADPCM IMA Loki SDL MJPEG @tab @tab X
515 @item ADPCM IMA WAV @tab X @tab X
516 @item ADPCM IMA Westwood @tab @tab X
517 @item ADPCM ISS IMA @tab @tab X
518 @tab Used in FunCom games.
519 @item ADPCM IMA Duck DK3 @tab @tab X
520 @tab Used in some Sega Saturn console games.
521 @item ADPCM IMA Duck DK4 @tab @tab X
522 @tab Used in some Sega Saturn console games.
523 @item ADPCM Microsoft @tab X @tab X
524 @item ADPCM MS IMA @tab X @tab X
525 @item ADPCM Nintendo Gamecube THP @tab @tab X
526 @item ADPCM QT IMA @tab X @tab X
527 @item ADPCM SEGA CRI ADX @tab X @tab X
528 @tab Used in Sega Dreamcast games.
529 @item ADPCM Shockwave Flash @tab X @tab X
530 @item ADPCM SMJPEG IMA @tab @tab X
531 @tab Used in certain Loki game ports.
532 @item ADPCM Sound Blaster Pro 2-bit @tab @tab X
533 @item ADPCM Sound Blaster Pro 2.6-bit @tab @tab X
534 @item ADPCM Sound Blaster Pro 4-bit @tab @tab X
535 @item ADPCM Westwood Studios IMA @tab @tab X
536 @tab Used in Westwood Studios games like Command and Conquer.
537 @item ADPCM Yamaha @tab X @tab X
538 @item AMR-NB @tab E @tab E
539 @tab supported through external libraries libamrnb and libopencore-amrnb
540 @item AMR-WB @tab E @tab E
541 @tab decoding supported through external libraries libamrwb and libopencore-amrwb,
542 encoding supported through external library libamrwb
543 @item Apple lossless audio @tab X @tab X
544 @tab QuickTime fourcc 'alac'
545 @item Atrac 3 @tab @tab X
546 @item Delphine Software International CIN audio @tab @tab X
547 @tab Codec used in Delphine Software International games.
548 @item COOK @tab @tab X
549 @tab All versions except 5.1 are supported.
550 @item DCA (DTS Coherent Acoustics) @tab @tab X
551 @item DPCM id RoQ @tab X @tab X
552 @tab Used in Quake III, Jedi Knight 2, other computer games.
553 @item DPCM Interplay @tab @tab X
554 @tab Used in various Interplay computer games.
555 @item DPCM Sierra Online @tab @tab X
556 @tab Used in Sierra Online game audio files.
557 @item DPCM Sol @tab @tab X
558 @item DPCM Xan @tab @tab X
559 @tab Used in Origin's Wing Commander IV AVI files.
560 @item DSP Group TrueSpeech @tab @tab X
561 @item DV audio @tab @tab X
562 @item Enhanced AC-3 @tab @tab X
563 @item FLAC (Free Lossless Audio Codec) @tab X @tab IX
564 @item G.729 @tab @tab X
565 @item GSM @tab E @tab E
566 @tab supported through external library libgsm
567 @item GSM Microsoft variant @tab E @tab E
568 @tab supported through external library libgsm
569 @item IMC (Intel Music Coder) @tab @tab X
570 @item MACE (Macintosh Audio Compression/Expansion) 3:1 @tab @tab X
571 @item MACE (Macintosh Audio Compression/Expansion) 6:1 @tab @tab X
572 @item MLP (Meridian Lossless Packing) @tab @tab X
573 @tab Used in DVD-Audio discs.
574 @item Monkey's Audio @tab @tab X
575 @tab Only versions 3.97-3.99 are supported.
576 @item MP1 (MPEG audio layer 1) @tab @tab IX
577 @item MP2 (MPEG audio layer 2) @tab IX @tab IX
578 @item MP3 (MPEG audio layer 3) @tab E @tab IX
579 @tab encoding supported through external library LAME, ADU MP3 and MP3onMP4 also supported
580 @item Musepack SV7 @tab @tab X
581 @item Musepack SV8 @tab @tab X
582 @item Nellymoser Asao @tab X @tab X
583 @item PCM A-law @tab X @tab X
584 @item PCM mu-law @tab X @tab X
585 @item PCM 16-bit little-endian planar @tab @tab X
586 @item PCM 32-bit floating point big-endian @tab X @tab X
587 @item PCM 32-bit floating point little-endian @tab X @tab X
588 @item PCM 64-bit floating point big-endian @tab X @tab X
589 @item PCM 64-bit floating point little-endian @tab X @tab X
590 @item PCM D-Cinema audio signed 24-bit @tab X @tab X
591 @item PCM signed 8-bit @tab X @tab X
592 @item PCM signed 16-bit big-endian @tab X @tab X
593 @item PCM signed 16-bit little-endian @tab X @tab X
594 @item PCM signed 24-bit big-endian @tab X @tab X
595 @item PCM signed 24-bit little-endian @tab X @tab X
596 @item PCM signed 32-bit big-endian @tab X @tab X
597 @item PCM signed 32-bit little-endian @tab X @tab X
598 @item PCM unsigned 8-bit @tab X @tab X
599 @item PCM unsigned 16-bit big-endian @tab X @tab X
600 @item PCM unsigned 16-bit little-endian @tab X @tab X
601 @item PCM unsigned 24-bit big-endian @tab X @tab X
602 @item PCM unsigned 24-bit little-endian @tab X @tab X
603 @item PCM unsigned 32-bit big-endian @tab X @tab X
604 @item PCM unsigned 32-bit little-endian @tab X @tab X
605 @item PCM Zork @tab X @tab X
606 @item QCELP / PureVoice @tab @tab X
607 @item QDesign Music Codec 2 @tab @tab X
608 @tab There are still some distortions.
609 @item RealAudio 1.0 (14.4K) @tab @tab X
610 @tab Real 14400 bit/s codec
611 @item RealAudio 2.0 (28.8K) @tab @tab X
612 @tab Real 28800 bit/s codec
613 @item RealAudio 3.0 (dnet) @tab IX @tab X
614 @tab Real low bitrate AC-3 codec
615 @item Shorten @tab @tab X
616 @item Sierra VMD audio @tab @tab X
617 @tab Used in Sierra VMD files.
618 @item Smacker audio @tab @tab X
619 @item Sonic @tab X @tab X
620 @tab experimental codec
621 @item Sonic lossless @tab X @tab X
622 @tab experimental codec
623 @item Speex @tab @tab E
624 @tab supported through external library libspeex
625 @item True Audio (TTA) @tab @tab X
626 @item TrueHD @tab @tab X
627 @tab Used in HD-DVD and Blu-Ray discs.
628 @item Vorbis @tab E @tab X
629 @ A native but very primitive encoder exists.
630 @item WavPack @tab @tab X
631 @item Westwood Audio (SND1) @tab @tab X
632 @item Windows Media Audio 1 @tab X @tab X
633 @item Windows Media Audio 2 @tab X @tab X
636 @code{X} means that encoding (resp. decoding) is supported.
638 @code{E} means that support is provided through an external library.
640 @code{I} means that an integer-only version is available, too (ensures high
641 performance on systems without hardware floating point support).
643 @section Subtitle Formats
645 @multitable @columnfractions .4 .1 .1 .1 .1
646 @item Name @tab Muxing @tab Demuxing @tab Encoding @tab Decoding
647 @item SSA/ASS @tab X @tab X
648 @item DVB @tab X @tab X @tab X @tab X
649 @item DVD @tab X @tab X @tab X @tab X
650 @item XSUB @tab @tab @tab @tab X
653 @code{X} means that the feature is supported.
655 @section Network Protocols
657 @multitable @columnfractions .4 .1
658 @item Name @tab Support
668 @code{X} means that the protocol is supported.
671 @section Input/Output Devices
673 @multitable @columnfractions .4 .1 .1
674 @item Name @tab Input @tab Output
675 @item ALSA @tab X @tab X
676 @item BEOS audio @tab X @tab X
677 @item BKTR @tab X @tab
678 @item DV1394 @tab X @tab
679 @item JACK @tab X @tab
680 @item LIBDC1394 @tab X @tab
681 @item OSS @tab X @tab X
682 @item Video4Linux @tab X @tab
683 @item Video4Linux2 @tab X @tab
684 @item VfW capture @tab X @tab
685 @item X11 grabbing @tab X @tab
688 @code{X} means that input/output is supported.
691 @chapter Platform Specific information
695 BSD make will not build FFmpeg, you need to install and use GNU Make
700 To get help and instructions for building FFmpeg under Windows, check out
701 the FFmpeg Windows Help Forum at
702 @url{http://ffmpeg.arrozcru.org/}.
704 @subsection Native Windows compilation
706 FFmpeg can be built to run natively on Windows using the MinGW tools. Install
707 the latest versions of MSYS and MinGW from @url{http://www.mingw.org/}.
708 You can find detailed installation
709 instructions in the download section and the FAQ.
711 FFmpeg does not build out-of-the-box with the packages the automated MinGW
712 installer provides. It also requires coreutils to be installed and many other
713 packages updated to the latest version. The minimum version for some packages
718 @item msys-make 3.81-2 (note: not mingw32-make)
720 @item mingw-runtime 3.15
723 FFmpeg automatically passes @code{-fno-common} to the compiler to work around
724 a GCC bug (see @url{http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37216}).
726 Within the MSYS shell, configure and make with:
729 ./configure --enable-memalign-hack --extra-cflags=-fno-common
734 This will install @file{ffmpeg.exe} along with many other development files
735 to @file{/usr/local}. You may specify another install path using the
736 @code{--prefix} option in @file{configure}.
742 @item In order to compile FFplay, you must have the MinGW development library
743 of SDL. Get it from @url{http://www.libsdl.org}.
744 Edit the @file{bin/sdl-config} script so that it points to the correct prefix
745 where SDL was installed. Verify that @file{sdl-config} can be launched from
746 the MSYS command line.
748 @item By using @code{./configure --enable-shared} when configuring FFmpeg,
749 you can build libavutil, libavcodec and libavformat as DLLs.
753 @subsection Microsoft Visual C++ compatibility
755 As stated in the FAQ, FFmpeg will not compile under MSVC++. However, if you
756 want to use the libav* libraries in your own applications, you can still
757 compile those applications using MSVC++. But the libav* libraries you link
758 to @emph{must} be built with MinGW. However, you will not be able to debug
759 inside the libav* libraries, since MSVC++ does not recognize the debug
760 symbols generated by GCC.
761 We strongly recommend you to move over from MSVC++ to MinGW tools.
763 This description of how to use the FFmpeg libraries with MSVC++ is based on
764 Microsoft Visual C++ 2005 Express Edition. If you have a different version,
765 you might have to modify the procedures slightly.
767 @subsubsection Using static libraries
769 Assuming you have just built and installed FFmpeg in @file{/usr/local}.
773 @item Create a new console application ("File / New / Project") and then
774 select "Win32 Console Application". On the appropriate page of the
775 Application Wizard, uncheck the "Precompiled headers" option.
777 @item Write the source code for your application, or, for testing, just
778 copy the code from an existing sample application into the source file
779 that MSVC++ has already created for you. For example, you can copy
780 @file{libavformat/output-example.c} from the FFmpeg distribution.
782 @item Open the "Project / Properties" dialog box. In the "Configuration"
783 combo box, select "All Configurations" so that the changes you make will
784 affect both debug and release builds. In the tree view on the left hand
785 side, select "C/C++ / General", then edit the "Additional Include
786 Directories" setting to contain the path where the FFmpeg includes were
787 installed (i.e. @file{c:\msys\1.0\local\include}).
788 Do not add MinGW's include directory here, or the include files will
789 conflict with MSVC's.
791 @item Still in the "Project / Properties" dialog box, select
792 "Linker / General" from the tree view and edit the
793 "Additional Library Directories" setting to contain the @file{lib}
794 directory where FFmpeg was installed (i.e. @file{c:\msys\1.0\local\lib}),
795 the directory where MinGW libs are installed (i.e. @file{c:\mingw\lib}),
796 and the directory where MinGW's GCC libs are installed
797 (i.e. @file{C:\mingw\lib\gcc\mingw32\4.2.1-sjlj}). Then select
798 "Linker / Input" from the tree view, and add the files @file{libavformat.a},
799 @file{libavcodec.a}, @file{libavutil.a}, @file{libmingwex.a},
800 @file{libgcc.a}, and any other libraries you used (i.e. @file{libz.a})
801 to the end of "Additional Dependencies".
803 @item Now, select "C/C++ / Code Generation" from the tree view. Select
804 "Debug" in the "Configuration" combo box. Make sure that "Runtime
805 Library" is set to "Multi-threaded Debug DLL". Then, select "Release" in
806 the "Configuration" combo box and make sure that "Runtime Library" is
807 set to "Multi-threaded DLL".
809 @item Click "OK" to close the "Project / Properties" dialog box.
811 @item MSVC++ lacks some C99 header files that are fundamental for FFmpeg.
812 Get msinttypes from @url{http://code.google.com/p/msinttypes/downloads/list}
813 and install it in MSVC++'s include directory
814 (i.e. @file{C:\Program Files\Microsoft Visual Studio 8\VC\include}).
816 @item MSVC++ also does not understand the @code{inline} keyword used by
817 FFmpeg, so you must add this line before @code{#include}ing libav*:
819 #define inline _inline
822 @item Build your application, everything should work.
826 @subsubsection Using shared libraries
828 This is how to create DLL and LIB files that are compatible with MSVC++:
832 @item Add a call to @file{vcvars32.bat} (which sets up the environment
833 variables for the Visual C++ tools) as the first line of @file{msys.bat}.
834 The standard location for @file{vcvars32.bat} is
835 @file{C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat},
836 and the standard location for @file{msys.bat} is @file{C:\msys\1.0\msys.bat}.
837 If this corresponds to your setup, add the following line as the first line
841 call "C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat"
844 Alternatively, you may start the @file{Visual Studio 2005 Command Prompt},
845 and run @file{c:\msys\1.0\msys.bat} from there.
847 @item Within the MSYS shell, run @code{lib.exe}. If you get a help message
848 from @file{Microsoft (R) Library Manager}, this means your environment
849 variables are set up correctly, the @file{Microsoft (R) Library Manager}
850 is on the path and will be used by FFmpeg to create
851 MSVC++-compatible import libraries.
853 @item Build FFmpeg with
856 ./configure --enable-shared --enable-memalign-hack
861 Your install path (@file{/usr/local/} by default) should now have the
862 necessary DLL and LIB files under the @file{bin} directory.
866 To use those files with MSVC++, do the same as you would do with
867 the static libraries, as described above. But in Step 4,
868 you should only need to add the directory where the LIB files are installed
869 (i.e. @file{c:\msys\usr\local\bin}). This is not a typo, the LIB files are
870 installed in the @file{bin} directory. And instead of adding @file{libxx.a}
871 files, you should add @file{avcodec.lib}, @file{avformat.lib}, and
872 @file{avutil.lib}. There should be no need for @file{libmingwex.a},
873 @file{libgcc.a}, and @file{wsock32.lib}, nor any other external library
874 statically linked into the DLLs. The @file{bin} directory contains a bunch
875 of DLL files, but the ones that are actually used to run your application
876 are the ones with a major version number in their filenames
877 (i.e. @file{avcodec-51.dll}).
879 @subsection Cross compilation for Windows with Linux
881 You must use the MinGW cross compilation tools available at
882 @url{http://www.mingw.org/}.
884 Then configure FFmpeg with the following options:
886 ./configure --target-os=mingw32 --cross-prefix=i386-mingw32msvc-
888 (you can change the cross-prefix according to the prefix chosen for the
891 Then you can easily test FFmpeg with Wine
892 (@url{http://www.winehq.com/}).
894 @subsection Compilation under Cygwin
896 The main issue with the 1.5.x Cygwin versions is that newlib, its C library,
897 does not contain llrint(). You need to upgrade to the unstable 1.7.x versions,
898 or leverage the implementation in MinGW (as explained below).
900 Just install your Cygwin with all the "Base" packages, plus the
901 following "Devel" ones:
903 binutils, gcc-core, make, subversion, mingw-runtime, diffutils
906 The experimental gcc4 package is still buggy, hence please
907 use the official gcc 3.4.4 or a 4.2.x compiled from source by yourself.
909 Install the current binutils-20080624-2 as they work fine (the old
910 binutils-20060709-1 proved buggy on shared builds).
912 Then create a small library that just contains llrint():
915 ar x /usr/lib/mingw/libmingwex.a llrint.o
916 ar cq /usr/local/lib/libllrint.a llrint.o
922 ./configure --enable-static --disable-shared --extra-ldflags='-L /usr/local/lib' --extra-libs='-l llrint'
925 to make a static build or
928 ./configure --enable-shared --disable-static --extra-ldflags='-L /usr/local/lib' --extra-libs='-l llrint'
931 to build shared libraries.
933 If you want to build FFmpeg with additional libraries, download Cygwin
934 "Devel" packages for Ogg and Vorbis from any Cygwin packages repository:
936 libogg-devel, libvorbis-devel
939 These library packages are only available from Cygwin Ports
940 (@url{http://sourceware.org/cygwinports/}) :
943 yasm, libSDL-devel, libdirac-devel, libfaac-devel, libfaad-devel, libgsm-devel,
944 libmp3lame-devel, libschroedinger1.0-devel, speex-devel, libtheora-devel,
948 The recommendation for libnut and x264 is to build them from source by
949 yourself, as they evolve too quickly for Cygwin Ports to be up to date.
951 Cygwin 1.7.x has IPv6 support. You can add IPv6 to Cygwin 1.5.x by means
952 of the @code{libgetaddrinfo-devel} package, available at Cygwin Ports.
954 @subsection Crosscompilation for Windows under Cygwin
956 With Cygwin you can create Windows binaries that do not need the cygwin1.dll.
958 Just install your Cygwin as explained before, plus these additional
961 gcc-mingw-core, mingw-runtime, mingw-zlib
964 and add some special flags to your configure invocation.
966 For a static build run
968 ./configure --target-os=mingw32 --enable-memalign-hack --enable-static --disable-shared --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
971 and for a build with shared libraries
973 ./configure --target-os=mingw32 --enable-memalign-hack --enable-shared --disable-static --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
978 BeOS support is broken in mysterious ways.
982 For information about compiling FFmpeg on OS/2 see
983 @url{http://www.edm2.com/index.php/FFmpeg}.
985 @chapter Developers Guide
989 @item libavcodec is the library containing the codecs (both encoding and
990 decoding). Look at @file{libavcodec/apiexample.c} to see how to use it.
992 @item libavformat is the library containing the file format handling (mux and
993 demux code for several formats). Look at @file{ffplay.c} to use it in a
994 player. See @file{libavformat/output-example.c} to use it to generate
995 audio or video streams.
999 @section Integrating libavcodec or libavformat in your program
1001 You can integrate all the source code of the libraries to link them
1002 statically to avoid any version problem. All you need is to provide a
1003 'config.mak' and a 'config.h' in the parent directory. See the defines
1004 generated by ./configure to understand what is needed.
1006 You can use libavcodec or libavformat in your commercial program, but
1007 @emph{any patch you make must be published}. The best way to proceed is
1008 to send your patches to the FFmpeg mailing list.
1011 @section Coding Rules
1013 FFmpeg is programmed in the ISO C90 language with a few additional
1014 features from ISO C99, namely:
1017 the @samp{inline} keyword;
1021 designated struct initializers (@samp{struct s x = @{ .i = 17 @};})
1023 compound literals (@samp{x = (struct s) @{ 17, 23 @};})
1026 These features are supported by all compilers we care about, so we will not
1027 accept patches to remove their use unless they absolutely do not impair
1028 clarity and performance.
1030 All code must compile with GCC 2.95 and GCC 3.3. Currently, FFmpeg also
1031 compiles with several other compilers, such as the Compaq ccc compiler
1032 or Sun Studio 9, and we would like to keep it that way unless it would
1033 be exceedingly involved. To ensure compatibility, please do not use any
1034 additional C99 features or GCC extensions. Especially watch out for:
1037 mixing statements and declarations;
1039 @samp{long long} (use @samp{int64_t} instead);
1041 @samp{__attribute__} not protected by @samp{#ifdef __GNUC__} or similar;
1043 GCC statement expressions (@samp{(x = (@{ int y = 4; y; @})}).
1047 The presentation is the one specified by 'indent -i4 -kr -nut'.
1048 The TAB character is forbidden outside of Makefiles as is any
1049 form of trailing whitespace. Commits containing either will be
1050 rejected by the Subversion repository.
1052 The main priority in FFmpeg is simplicity and small code size in order to
1053 minimize the bug count.
1055 Comments: Use the JavaDoc/Doxygen
1056 format (see examples below) so that code documentation
1057 can be generated automatically. All nontrivial functions should have a comment
1058 above them explaining what the function does, even if it is just one sentence.
1059 All structures and their member variables should be documented, too.
1072 typedef struct Foobar@{
1073 int var1; /**< var1 description */
1074 int var2; ///< var2 description
1075 /** var3 description */
1083 * @@param my_parameter description of my_parameter
1084 * @@return return value description
1086 int myfunc(int my_parameter)
1090 fprintf and printf are forbidden in libavformat and libavcodec,
1091 please use av_log() instead.
1093 Casts should be used only when necessary. Unneeded parentheses
1094 should also be avoided if they don't make the code easier to understand.
1096 @section Development Policy
1100 Contributions should be licensed under the LGPL 2.1, including an
1101 "or any later version" clause, or the MIT license. GPL 2 including
1102 an "or any later version" clause is also acceptable, but LGPL is
1105 You must not commit code which breaks FFmpeg! (Meaning unfinished but
1106 enabled code which breaks compilation or compiles but does not work or
1107 breaks the regression tests)
1108 You can commit unfinished stuff (for testing etc), but it must be disabled
1109 (#ifdef etc) by default so it does not interfere with other developers'
1112 You do not have to over-test things. If it works for you, and you think it
1113 should work for others, then commit. If your code has problems
1114 (portability, triggers compiler bugs, unusual environment etc) they will be
1115 reported and eventually fixed.
1117 Do not commit unrelated changes together, split them into self-contained
1118 pieces. Also do not forget that if part B depends on part A, but A does not
1119 depend on B, then A can and should be committed first and separate from B.
1120 Keeping changes well split into self-contained parts makes reviewing and
1121 understanding them on the commit log mailing list easier. This also helps
1122 in case of debugging later on.
1123 Also if you have doubts about splitting or not splitting, do not hesitate to
1124 ask/discuss it on the developer mailing list.
1126 Do not change behavior of the program (renaming options etc) without
1127 first discussing it on the ffmpeg-devel mailing list. Do not remove
1128 functionality from the code. Just improve!
1130 Note: Redundant code can be removed.
1132 Do not commit changes to the build system (Makefiles, configure script)
1133 which change behavior, defaults etc, without asking first. The same
1134 applies to compiler warning fixes, trivial looking fixes and to code
1135 maintained by other developers. We usually have a reason for doing things
1136 the way we do. Send your changes as patches to the ffmpeg-devel mailing
1137 list, and if the code maintainers say OK, you may commit. This does not
1138 apply to files you wrote and/or maintain.
1140 We refuse source indentation and other cosmetic changes if they are mixed
1141 with functional changes, such commits will be rejected and removed. Every
1142 developer has his own indentation style, you should not change it. Of course
1143 if you (re)write something, you can use your own style, even though we would
1144 prefer if the indentation throughout FFmpeg was consistent (Many projects
1145 force a given indentation style - we do not.). If you really need to make
1146 indentation changes (try to avoid this), separate them strictly from real
1149 NOTE: If you had to put if()@{ .. @} over a large (> 5 lines) chunk of code,
1150 then either do NOT change the indentation of the inner part within (do not
1151 move it to the right)! or do so in a separate commit
1153 Always fill out the commit log message. Describe in a few lines what you
1154 changed and why. You can refer to mailing list postings if you fix a
1155 particular bug. Comments such as "fixed!" or "Changed it." are unacceptable.
1157 If you apply a patch by someone else, include the name and email address in
1158 the log message. Since the ffmpeg-cvslog mailing list is publicly
1159 archived you should add some SPAM protection to the email address. Send an
1160 answer to ffmpeg-devel (or wherever you got the patch from) saying that
1161 you applied the patch.
1163 When applying patches that have been discussed (at length) on the mailing
1164 list, reference the thread in the log message.
1166 Do NOT commit to code actively maintained by others without permission.
1167 Send a patch to ffmpeg-devel instead. If no one answers within a reasonable
1168 timeframe (12h for build failures and security fixes, 3 days small changes,
1169 1 week for big patches) then commit your patch if you think it is OK.
1170 Also note, the maintainer can simply ask for more time to review!
1172 Subscribe to the ffmpeg-cvslog mailing list. The diffs of all commits
1173 are sent there and reviewed by all the other developers. Bugs and possible
1174 improvements or general questions regarding commits are discussed there. We
1175 expect you to react if problems with your code are uncovered.
1177 Update the documentation if you change behavior or add features. If you are
1178 unsure how best to do this, send a patch to ffmpeg-devel, the documentation
1179 maintainer(s) will review and commit your stuff.
1181 Try to keep important discussions and requests (also) on the public
1182 developer mailing list, so that all developers can benefit from them.
1184 Never write to unallocated memory, never write over the end of arrays,
1185 always check values read from some untrusted source before using them
1186 as array index or other risky things.
1188 Remember to check if you need to bump versions for the specific libav
1189 parts (libavutil, libavcodec, libavformat) you are changing. You need
1190 to change the version integer.
1191 Incrementing the first component means no backward compatibility to
1192 previous versions (e.g. removal of a function from the public API).
1193 Incrementing the second component means backward compatible change
1194 (e.g. addition of a function to the public API or extension of an
1195 existing data structure).
1196 Incrementing the third component means a noteworthy binary compatible
1197 change (e.g. encoder bug fix that matters for the decoder).
1199 Compiler warnings indicate potential bugs or code with bad style. If a type of
1200 warning always points to correct and clean code, that warning should
1201 be disabled, not the code changed.
1202 Thus the remaining warnings can either be bugs or correct code.
1203 If it is a bug, the bug has to be fixed. If it is not, the code should
1204 be changed to not generate a warning unless that causes a slowdown
1205 or obfuscates the code.
1207 If you add a new file, give it a proper license header. Do not copy and
1208 paste it from a random place, use an existing file as template.
1211 We think our rules are not too hard. If you have comments, contact us.
1213 Note, these rules are mostly borrowed from the MPlayer project.
1215 @section Submitting patches
1217 First, (@pxref{Coding Rules}) above if you did not yet.
1219 When you submit your patch, try to send a unified diff (diff '-up'
1220 option). We cannot read other diffs :-)
1222 Also please do not submit a patch which contains several unrelated changes.
1223 Split it into separate, self-contained pieces. This does not mean splitting
1224 file by file. Instead, make the patch as small as possible while still
1225 keeping it as a logical unit that contains an individual change, even
1226 if it spans multiple files. This makes reviewing your patches much easier
1227 for us and greatly increases your chances of getting your patch applied.
1229 Run the regression tests before submitting a patch so that you can
1230 verify that there are no big problems.
1232 Patches should be posted as base64 encoded attachments (or any other
1233 encoding which ensures that the patch will not be trashed during
1234 transmission) to the ffmpeg-devel mailing list, see
1235 @url{http://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel}
1237 It also helps quite a bit if you tell us what the patch does (for example
1238 'replaces lrint by lrintf'), and why (for example '*BSD isn't C99 compliant
1239 and has no lrint()')
1241 Also please if you send several patches, send each patch as a separate mail,
1242 do not attach several unrelated patches to the same mail.
1244 @section New codecs or formats checklist
1248 Did you use av_cold for codec initialization and close functions?
1250 Did you add a long_name under NULL_IF_CONFIG_SMALL to the AVCodec or
1251 AVInputFormat/AVOutputFormat struct?
1253 Did you bump the minor version number in @file{avcodec.h} or
1256 Did you register it in @file{allcodecs.c} or @file{allformats.c}?
1258 Did you add the CodecID to @file{avcodec.h}?
1260 If it has a fourcc, did you add it to @file{libavformat/riff.c},
1261 even if it is only a decoder?
1263 Did you add a rule to compile the appropriate files in the Makefile?
1264 Remember to do this even if you're just adding a format to a file that is
1265 already being compiled by some other rule, like a raw demuxer.
1267 Did you add an entry to the table of supported formats or codecs in the
1270 Did you add an entry in the Changelog?
1272 If it depends on a parser or a library, did you add that dependency in
1275 Did you "svn add" the appropriate files before commiting?
1278 @section patch submission checklist
1282 Do the regression tests pass with the patch applied?
1284 Does @code{make checkheaders} pass with the patch applied?
1286 Is the patch a unified diff?
1288 Is the patch against latest FFmpeg SVN?
1290 Are you subscribed to ffmpeg-dev?
1291 (the list is subscribers only due to spam)
1293 Have you checked that the changes are minimal, so that the same cannot be
1294 achieved with a smaller patch and/or simpler final code?
1296 If the change is to speed critical code, did you benchmark it?
1298 If you did any benchmarks, did you provide them in the mail?
1300 Have you checked that the patch does not introduce buffer overflows or
1301 other security issues?
1303 Did you test your decoder or demuxer against damaged data? If no, see
1304 tools/trasher and the noise bitstream filter. Your decoder or demuxer
1305 should not crash or end in a (near) infinite loop when fed damaged data.
1307 Is the patch created from the root of the source tree, so it can be
1308 applied with @code{patch -p0}?
1310 Does the patch not mix functional and cosmetic changes?
1312 Did you add tabs or trailing whitespace to the code? Both are forbidden.
1314 Is the patch attached to the email you send?
1316 Is the mime type of the patch correct? It should be text/x-diff or
1317 text/x-patch or at least text/plain and not application/octet-stream.
1319 If the patch fixes a bug, did you provide a verbose analysis of the bug?
1321 If the patch fixes a bug, did you provide enough information, including
1322 a sample, so the bug can be reproduced and the fix can be verified?
1323 Note please do not attach samples >100k to mails but rather provide a
1324 URL, you can upload to ftp://upload.ffmpeg.org
1326 Did you provide a verbose summary about what the patch does change?
1328 Did you provide a verbose explanation why it changes things like it does?
1330 Did you provide a verbose summary of the user visible advantages and
1331 disadvantages if the patch is applied?
1333 Did you provide an example so we can verify the new feature added by the
1336 If you added a new file, did you insert a license header? It should be
1337 taken from FFmpeg, not randomly copied and pasted from somewhere else.
1339 You should maintain alphabetical order in alphabetically ordered lists as
1340 long as doing so does not break API/ABI compatibility.
1342 Lines with similar content should be aligned vertically when doing so
1343 improves readability.
1345 Did you provide a suggestion for a clear commit log message?
1348 @section Patch review process
1350 All patches posted to ffmpeg-devel will be reviewed, unless they contain a
1351 clear note that the patch is not for SVN.
1352 Reviews and comments will be posted as replies to the patch on the
1353 mailing list. The patch submitter then has to take care of every comment,
1354 that can be by resubmitting a changed patch or by discussion. Resubmitted
1355 patches will themselves be reviewed like any other patch. If at some point
1356 a patch passes review with no comments then it is approved, that can for
1357 simple and small patches happen immediately while large patches will generally
1358 have to be changed and reviewed many times before they are approved.
1359 After a patch is approved it will be committed to the repository.
1361 We will review all submitted patches, but sometimes we are quite busy so
1362 especially for large patches this can take several weeks.
1364 When resubmitting patches, please do not make any significant changes
1365 not related to the comments received during review. Such patches will
1366 be rejected. Instead, submit significant changes or new features as
1369 @section Regression tests
1371 Before submitting a patch (or committing to the repository), you should at least
1372 test that you did not break anything.
1374 The regression tests build a synthetic video stream and a synthetic
1375 audio stream. These are then encoded and decoded with all codecs or
1376 formats. The CRC (or MD5) of each generated file is recorded in a
1377 result file. A 'diff' is launched to compare the reference results and
1380 The regression tests then go on to test the FFserver code with a
1381 limited set of streams. It is important that this step runs correctly
1384 Run 'make test' to test all the codecs and formats.
1386 Run 'make fulltest' to test all the codecs, formats and FFserver.
1388 [Of course, some patches may change the results of the regression tests. In
1389 this case, the reference results of the regression tests shall be modified