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 Supported File Format @tab Encoding @tab Decoding @tab Comments
45 @tab 4X Technologies format, used in some games.
46 @item ADTS AAC audio @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 ASF @tab X @tab X
50 @item AVI @tab X @tab X
51 @item AVM2 (Flash 9) @tab X @tab X
52 @tab Only embedded audio is decoded.
54 @tab Multimedia format used by the Creature Shock game.
55 @item Bethsoft VID @tab @tab X
56 @tab Used in some games from Bethesda Softworks.
58 @tab Brute Force & Ignorance, used in Flash Traffic: City of Angels.
60 @tab Used in the game Cyberia from Interplay.
62 @tab Multimedia format used by Delphine Software games.
63 @item Creative VOC @tab X @tab X
64 @tab Created for the Sound Blaster Pro.
65 @item CRYO APC @tab @tab X
66 @tab Audio format used in some games by CRYO Interactive Entertainment.
67 @item DV @tab X @tab X
69 @tab This format is used in the non-Windows version of the Feeble Files
70 game and different game cutscenes repacked for use with ScummVM.
71 @item Electronic Arts Multimedia @tab @tab X
72 @tab Used in various EA games; files have extensions like WVE and UV2.
73 @item FLIC @tab @tab X
75 @item FLV @tab X @tab X
76 @tab Macromedia Flash video files
77 @item GXF @tab X @tab X
78 @tab General eXchange Format SMPTE 360M, used by Thomson Grass Valley
80 @item id Cinematic @tab @tab X
81 @tab Used in Quake II.
82 @item id RoQ @tab X @tab X
83 @tab Used in Quake III, Jedi Knight 2, other computer games.
85 @tab Interchange File Format
86 @item Interplay MVE @tab @tab X
87 @tab Format used in various Interplay computer games.
88 @item LMLM4 @tab @tab X
89 @tab Used by Linux Media Labs MPEG-4 PCI boards
90 @item Matroska @tab X @tab X
91 @item MAXIS EA XA @tab @tab X
92 @tab Used in Sim City 3000; file extension .xa.
93 @item Monkey's Audio @tab @tab X
94 @item Motion Pixels MVI @tab @tab X
95 @item MOV/QuickTime @tab X @tab X
96 @item MPEG audio @tab X @tab X
97 @item MPEG-1 systems @tab X @tab X
98 @tab muxed audio and video
99 @item MPEG-2 PS @tab X @tab X
100 @tab also known as @code{VOB} file
101 @item MPEG-2 TS @tab @tab X
102 @tab also known as DVB Transport Stream
103 @item MPEG-4 @tab X @tab X
104 @tab MPEG-4 is a variant of QuickTime.
105 @item MSN TCP webcam @tab @tab X
106 @tab Used by MSN Messenger webcam streams.
107 @item MXF @tab @tab X
108 @tab Material eXchange Format SMPTE 377M, used by D-Cinema, broadcast industry.
109 @item Nullsoft Video @tab @tab X
110 @item NUT @tab X @tab X
111 @tab NUT Open Container Format
112 @item OMA @tab @tab X
113 @tab Audio format used in Sony Sonic Stage and Sony Vegas.
114 @item PlayStation STR @tab @tab X
115 @item PVA @tab @tab X
116 @tab Used by TechnoTrend DVB PCI boards.
117 @item raw AC-3 @tab X @tab X
118 @item raw CRI ADX audio @tab X @tab X
119 @item raw MJPEG @tab X @tab X
120 @item raw MPEG video @tab X @tab X
121 @item raw MPEG-4 video @tab X @tab X
122 @item raw PCM 8/16/32 bits, 32/64-bit floating point, mu-law/A-law @tab X @tab X
123 @item raw Shorten audio @tab @tab X
124 @item RealMedia @tab X @tab X
125 @item RL2 @tab @tab X
126 @tab Audio and video format used in some games by Entertainment Software Partners.
127 @item Sega FILM/CPK @tab @tab X
128 @tab Used in many Sega Saturn console games.
129 @item SEQ @tab @tab X
130 @tab Tiertex .seq files used in the DOS CD-ROM version of the game Flashback.
131 @item Sierra Online @tab @tab X
132 @tab .sol files used in Sierra Online games.
133 @item Sierra VMD @tab @tab X
134 @tab Used in Sierra CD-ROM games.
135 @item SIFF @tab @tab X
136 @tab Audio and video format used in some games by Beam Software.
137 @item Smacker @tab @tab X
138 @tab Multimedia format used by many games.
139 @item SUN AU format @tab X @tab X
140 @item THP @tab @tab X
141 @tab Used on the Nintendo GameCube.
142 @item WAV @tab X @tab X
143 @item WC3 Movie @tab @tab X
144 @tab Multimedia format used in Origin's Wing Commander III computer game.
145 @item Westwood Studios VQA/AUD @tab @tab X
146 @tab Multimedia formats used in Westwood Studios games.
149 @code{X} means that encoding (resp. decoding) is supported.
151 @section Image Formats
153 FFmpeg can read and write images for each frame of a video sequence. The
154 following image formats are supported:
156 @multitable @columnfractions .4 .1 .1 .4
157 @item Supported Image Format @tab Encoding @tab Decoding @tab Comments
158 @item .Y.U.V @tab X @tab X @tab one raw file per component
159 @item animated GIF @tab X @tab X @tab Only uncompressed GIFs are generated.
160 @item JPEG @tab X @tab X @tab Progressive JPEG is not supported.
161 @item PAM @tab X @tab X @tab PAM is a PNM extension with alpha support.
162 @item PCX @tab @tab X @tab PC Paintbrush
163 @item PGM, PPM @tab X @tab X
164 @item PGMYUV @tab X @tab X @tab PGM with U and V components in YUV 4:2:0
165 @item PNG @tab X @tab X @tab 2/4 bpp not supported yet
166 @item PTX @tab @tab X @tab V.Flash PTX format
167 @item RAS @tab @tab X @tab Sun Rasterfile
168 @item SGI @tab X @tab X @tab SGI RGB image format
169 @item Targa @tab @tab X @tab Targa (.TGA) image format
170 @item TIFF @tab X @tab X @tab YUV, JPEG and some extension is not supported yet.
173 @code{X} means that encoding (resp. decoding) is supported.
175 @section Video Codecs
177 @multitable @columnfractions .4 .1 .1 .4
178 @item Supported Codec @tab Encoding @tab Decoding @tab Comments
179 @item 4X Video @tab @tab X
180 @tab Used in certain computer games.
181 @item American Laser Games Video @tab @tab X
182 @tab Used in games like Mad Dog McCree.
183 @item AMV @tab @tab X
184 @tab Used in Chinese MP3 players.
185 @item Apple Animation @tab X @tab X
187 @item Apple Graphics @tab @tab X
189 @item Apple MJPEG-B @tab @tab X
190 @item Apple QuickDraw @tab @tab X
192 @item Apple Video @tab @tab X
194 @item Asus v1 @tab X @tab X
196 @item Asus v2 @tab X @tab X
198 @item ATI VCR1 @tab @tab X
200 @item ATI VCR2 @tab @tab X
202 @item Autodesk RLE @tab @tab X
204 @item AVID DNxHD @tab X @tab X
206 @item AVS video @tab @tab X
207 @tab Video encoding used by the Creature Shock game.
208 @item Bethsoft VID @tab @tab X
209 @tab Used in some games from Bethesda Softworks.
210 @item C93 video @tab @tab X
211 @tab Codec used in Cyberia game.
212 @item CamStudio @tab @tab X
214 @item Cin video @tab @tab X
215 @tab Codec used in Delphine Software games.
216 @item Cinepak @tab @tab X
217 @item Cirrus Logic AccuPak @tab @tab X
219 @item Creative YUV @tab @tab X
221 @item Dirac @tab X @tab X
222 @tab Supported through the external libdirac/libschroedinger libraries.
223 @item Duck TrueMotion v1 @tab @tab X
225 @item Duck TrueMotion v2 @tab @tab X
227 @item DV @tab X @tab X
228 @item DXA Video @tab @tab X
229 @tab Codec originally used in Feeble Files game.
230 @item Electronic Arts CMV @tab @tab X
231 @tab Used in NHL 95 game.
232 @item Electronic Arts TGV @tab @tab X
233 @item FFmpeg Video 1 @tab X @tab X
234 @tab experimental lossless codec (fourcc: FFV1)
235 @item Flash Screen Video @tab X @tab X
237 @item FLIC video @tab @tab X
238 @item FLV @tab X @tab X
239 @tab Sorenson H.263 used in Flash
240 @item Fraps FPS1 @tab @tab X
241 @item H.261 @tab X @tab X
242 @item H.263(+) @tab X @tab X
243 @tab also known as RealVideo 1.0
244 @item H.264 @tab @tab X
245 @item HuffYUV @tab X @tab X
246 @item IBM Ultimotion @tab @tab X
248 @item id Cinematic video @tab @tab X
249 @tab Used in Quake II.
250 @item id RoQ @tab X @tab X
251 @tab Used in Quake III, Jedi Knight 2, other computer games.
252 @item Intel Indeo 3 @tab @tab X
253 @item Interplay Video @tab @tab X
254 @tab Used in Interplay .MVE files.
255 @item JPEG-LS @tab X @tab X
256 @tab fourcc: MJLS, lossless and near-lossless is supported.
257 @item KMVC @tab @tab X
258 @tab Codec used in Worms games.
259 @item LOCO @tab @tab X
260 @item lossless MJPEG @tab X @tab X
261 @item Microsoft RLE @tab @tab X
262 @item Microsoft Video-1 @tab @tab X
263 @item Mimic @tab @tab X
264 @tab Used in MSN Messenger Webcam streams.
265 @item Miro VideoXL @tab @tab X
267 @item MJPEG @tab X @tab X
268 @item Motion Pixels Video @tab @tab X
269 @item MPEG-1 @tab X @tab X
270 @item MPEG-2 @tab X @tab X
271 @item MPEG-4 @tab X @tab X
272 @item MSMPEG4 V1 @tab X @tab X
273 @item MSMPEG4 V2 @tab X @tab X
274 @item MSMPEG4 V3 @tab X @tab X
275 @item MSZH @tab @tab X
277 @item On2 VP3 @tab @tab X
278 @tab still experimental
279 @item On2 VP5 @tab @tab X
281 @item On2 VP6 @tab @tab X
282 @tab fourcc: VP60,VP61,VP62
283 @item planar RGB @tab @tab X
285 @item QPEG @tab @tab X
286 @tab fourccs: QPEG, Q1.0, Q1.1
287 @item RealVideo 1.0 @tab X @tab X
288 @item RealVideo 2.0 @tab X @tab X
289 @item Renderware TXD @tab @tab X
290 @tab Texture dictionaries used by the Renderware Engine.
291 @item RTjpeg @tab @tab X
292 @tab Video encoding used in NuppelVideo files.
293 @item Smacker video @tab @tab X
294 @tab Video encoding used in Smacker.
295 @item Snow @tab X @tab X
296 @tab experimental wavelet codec (fourcc: SNOW)
297 @item Sony PlayStation MDEC @tab @tab X
298 @item Sorenson Video 1 @tab X @tab X
300 @item Sorenson Video 3 @tab @tab X
302 @item Sunplus MJPEG @tab @tab X
304 @item TechSmith Camtasia @tab @tab X
306 @item Theora @tab X @tab X
307 @tab still experimental
308 @item THP @tab @tab X
309 @tab Used on the Nintendo GameCube.
310 @item Tiertex Seq video @tab @tab X
311 @tab Codec used in DOS CD-ROM FlashBack game.
312 @item VC-1 @tab @tab X
313 @item VMD Video @tab @tab X
314 @tab Used in Sierra VMD files.
315 @item VMware Video @tab @tab X
316 @tab Codec used in videos captured by VMware.
317 @item Westwood VQA @tab @tab X
318 @item Winnov WNV1 @tab @tab X
319 @item WMV7 @tab X @tab X
320 @item WMV8 @tab X @tab X
321 @item WMV9 @tab @tab X
322 @tab not completely working
323 @item Xan/WC3 @tab @tab X
324 @tab Used in Wing Commander III .MVE files.
325 @item ZLIB @tab X @tab X
326 @tab part of LCL, encoder experimental
327 @item ZMBV @tab X @tab X
328 @tab Encoder works only in PAL8.
331 @code{X} means that encoding (resp. decoding) is supported.
333 @section Audio Codecs
335 @multitable @columnfractions .4 .1 .1 .1 .7
336 @item Supported Codec @tab Encoding @tab Decoding @tab Comments
337 @item 4X IMA ADPCM @tab @tab X
338 @item 8SVX audio @tab @tab X
339 @item AAC @tab X @tab X
340 @tab Encoding is supported through the external library libfaac.
341 @item AC-3 @tab IX @tab IX
342 @tab liba52 can be used alternatively for decoding.
343 @item AMR-NB @tab X @tab X
344 @tab Supported through an external library.
345 @item AMR-WB @tab X @tab X
346 @tab Supported through an external library.
347 @item AMV IMA ADPCM @tab @tab X
348 @tab Used in AMV files
349 @item Apple lossless audio @tab X @tab X
350 @tab QuickTime fourcc 'alac'
351 @item Apple MACE 3 @tab @tab X
352 @item Apple MACE 6 @tab @tab X
353 @item ATRAC 3 @tab @tab X
354 @item CD-ROM XA ADPCM @tab @tab X
355 @item Cin audio @tab @tab X
356 @tab Codec used in Delphine Software International games.
357 @item Creative ADPCM @tab @tab X
358 @tab 16 -> 4, 8 -> 4, 8 -> 3, 8 -> 2
359 @item CRI ADX ADPCM @tab X @tab X
360 @tab Used in Sega Dreamcast games.
361 @item DSP Group TrueSpeech @tab @tab X
362 @item DTS Coherent Audio @tab @tab X
363 @item Duck DK3 IMA ADPCM @tab @tab X
364 @tab Used in some Sega Saturn console games.
365 @item Duck DK4 IMA ADPCM @tab @tab X
366 @tab Used in some Sega Saturn console games.
367 @item DV audio @tab @tab X
368 @item Electronic Arts ADPCM @tab @tab X
369 @tab Used in various EA titles.
370 @item Sonic @tab X @tab X
371 @tab experimental codec
372 @item Sonic lossless @tab X @tab X
373 @tab experimental codec
374 @item FLAC lossless audio @tab X @tab X
375 @item G.726 ADPCM @tab X @tab X
376 @item id RoQ DPCM @tab X @tab X
377 @tab Used in Quake III, Jedi Knight 2, other computer games.
378 @item Intel Music Coder @tab @tab X
379 @item Interplay MVE DPCM @tab @tab X
380 @tab Used in various Interplay computer games.
381 @item MAXIS EA ADPCM @tab @tab X
382 @tab Used in Sim City 3000.
383 @item Microsoft ADPCM @tab X @tab X
384 @item MLP/TrueHD @tab @tab X
385 @tab Used in DVD-Audio and Blu-Ray discs.
386 @item Monkey's Audio @tab @tab X
387 @tab Only versions 3.97-3.99 are supported.
388 @item MPEG audio layer 1/3 @tab X @tab IX
389 @tab MP3 encoding is supported through the external library LAME.
390 @item MPEG audio layer 2 @tab IX @tab IX
391 @item MS IMA ADPCM @tab X @tab X
392 @item Musepack @tab @tab X
393 @tab SV7 and SV8 are supported.
394 @item Nellymoser ASAO @tab @tab X
395 @item Qdesign QDM2 @tab @tab X
396 @tab There are still some distortions.
397 @item QT IMA ADPCM @tab X @tab X
398 @item RA144 @tab @tab X
399 @tab Real 14400 bit/s codec
400 @item RA288 @tab @tab X
401 @tab Real 28800 bit/s codec
402 @item RADnet @tab X @tab IX
403 @tab real low bitrate AC-3 codec
404 @item Real COOK @tab @tab X
405 @tab All versions except 5.1 are supported.
406 @item Shorten @tab @tab X
407 @item Sierra Online DPCM @tab @tab X
408 @tab Used in Sierra Online game audio files.
409 @item Smacker audio @tab @tab X
410 @item SMJPEG IMA ADPCM @tab @tab X
411 @tab Used in certain Loki game ports.
412 @item THP ADPCM @tab @tab X
413 @tab Used on the Nintendo GameCube.
414 @item True Audio (TTA) @tab @tab X
415 @item Vorbis @tab X @tab X
416 @item WavPack @tab @tab X
417 @item Westwood Studios IMA ADPCM @tab @tab X
418 @tab Used in Westwood Studios games like Command and Conquer.
419 @item WMA v1/v2 @tab X @tab X
420 @item Xan DPCM @tab @tab X
421 @tab Used in Origin's Wing Commander IV AVI files.
424 @code{X} means that encoding (resp. decoding) is supported.
426 @code{I} means that an integer-only version is available, too (ensures high
427 performance on systems without hardware floating point support).
429 @chapter Platform Specific information
433 BSD make will not build FFmpeg, you need to install and use GNU Make
438 To get help and instructions for building FFmpeg under Windows, check out
439 the FFmpeg Windows Help Forum at
440 @url{http://arrozcru.no-ip.org/ffmpeg/}.
442 @subsection Native Windows compilation
444 FFmpeg can be built to run natively on Windows using the MinGW tools. Install
445 the current versions of MSYS and MinGW from @url{http://www.mingw.org/}. Also
446 install the coreutils package, and update to the latest MSYS make (note: not
447 mingw32-make). You can find detailed installation
448 instructions in the download section and the FAQ.
450 Within the MSYS shell, configure and make with:
453 ./configure --enable-memalign-hack
458 This will install @file{ffmpeg.exe} along with many other development files
459 to @file{/usr/local}. You may specify another install path using the
460 @code{--prefix} option in @file{configure}.
466 @item Use at least bash 3.1. Older versions are known to fail on the
469 @item In order to compile vhooks, you must have a POSIX-compliant libdl in
470 your MinGW system. Get dlfcn-win32 from
471 @url{http://code.google.com/p/dlfcn-win32}.
473 @item In order to compile FFplay, you must have the MinGW development library
474 of SDL. Get it from @url{http://www.libsdl.org}.
475 Edit the @file{bin/sdl-config} script so that it points to the correct prefix
476 where SDL was installed. Verify that @file{sdl-config} can be launched from
477 the MSYS command line.
479 @item By using @code{./configure --enable-shared} when configuring FFmpeg,
480 you can build libavutil, libavcodec and libavformat as DLLs.
484 @subsection Microsoft Visual C++ compatibility
486 As stated in the FAQ, FFmpeg will not compile under MSVC++. However, if you
487 want to use the libav* libraries in your own applications, you can still
488 compile those applications using MSVC++. But the libav* libraries you link
489 to @emph{must} be built with MinGW. However, you will not be able to debug
490 inside the libav* libraries, since MSVC++ does not recognize the debug
491 symbols generated by GCC.
492 We strongly recommend you to move over from MSVC++ to MinGW tools.
494 This description of how to use the FFmpeg libraries with MSVC++ is based on
495 Microsoft Visual C++ 2005 Express Edition. If you have a different version,
496 you might have to modify the procedures slightly.
498 @subsubsection Using static libraries
500 Assuming you have just built and installed FFmpeg in @file{/usr/local}.
504 @item Create a new console application ("File / New / Project") and then
505 select "Win32 Console Application". On the appropriate page of the
506 Application Wizard, uncheck the "Precompiled headers" option.
508 @item Write the source code for your application, or, for testing, just
509 copy the code from an existing sample application into the source file
510 that MSVC++ has already created for you. For example, you can copy
511 @file{output_example.c} from the FFmpeg distribution.
513 @item Open the "Project / Properties" dialog box. In the "Configuration"
514 combo box, select "All Configurations" so that the changes you make will
515 affect both debug and release builds. In the tree view on the left hand
516 side, select "C/C++ / General", then edit the "Additional Include
517 Directories" setting to contain the path where the FFmpeg includes were
518 installed (i.e. @file{c:\msys\1.0\local\include}).
519 Do not add MinGW's include directory here, or the include files will
520 conflict with MSVC's.
522 @item Still in the "Project / Properties" dialog box, select
523 "Linker / General" from the tree view and edit the
524 "Additional Library Directories" setting to contain the @file{lib}
525 directory where FFmpeg was installed (i.e. @file{c:\msys\1.0\local\lib}),
526 the directory where MinGW libs are installed (i.e. @file{c:\mingw\lib}),
527 and the directory where MinGW's GCC libs are installed
528 (i.e. @file{C:\mingw\lib\gcc\mingw32\4.2.1-sjlj}). Then select
529 "Linker / Input" from the tree view, and add the files @file{libavformat.a},
530 @file{libavcodec.a}, @file{libavutil.a}, @file{libmingwex.a},
531 @file{libgcc.a}, and any other libraries you used (i.e. @file{libz.a})
532 to the end of "Additional Dependencies".
534 @item Now, select "C/C++ / Code Generation" from the tree view. Select
535 "Debug" in the "Configuration" combo box. Make sure that "Runtime
536 Library" is set to "Multi-threaded Debug DLL". Then, select "Release" in
537 the "Configuration" combo box and make sure that "Runtime Library" is
538 set to "Multi-threaded DLL".
540 @item Click "OK" to close the "Project / Properties" dialog box.
542 @item MSVC++ lacks some C99 header files that are fundamental for FFmpeg.
543 Get msinttypes from @url{http://code.google.com/p/msinttypes/downloads/list}
544 and install it in MSVC++'s include directory
545 (i.e. @file{C:\Program Files\Microsoft Visual Studio 8\VC\include}).
547 @item MSVC++ also does not understand the @code{inline} keyword used by
548 FFmpeg, so you must add this line before @code{#include}ing libav*:
550 #define inline _inline
553 @item Build your application, everything should work.
557 @subsubsection Using shared libraries
559 This is how to create DLL and LIB files that are compatible with MSVC++:
563 @item Add a call to @file{vcvars32.bat} (which sets up the environment
564 variables for the Visual C++ tools) as the first line of @file{msys.bat}.
565 The standard location for @file{vcvars32.bat} is
566 @file{C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat},
567 and the standard location for @file{msys.bat} is @file{C:\msys\1.0\msys.bat}.
568 If this corresponds to your setup, add the following line as the first line
572 call "C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat"
575 Alternatively, you may start the @file{Visual Studio 2005 Command Prompt},
576 and run @file{c:\msys\1.0\msys.bat} from there.
578 @item Within the MSYS shell, run @code{lib.exe}. If you get a help message
579 from @file{Microsoft (R) Library Manager}, this means your environment
580 variables are set up correctly, the @file{Microsoft (R) Library Manager}
581 is on the path and will be used by FFmpeg to create
582 MSVC++-compatible import libraries.
584 @item Build FFmpeg with
587 ./configure --enable-shared --enable-memalign-hack
592 Your install path (@file{/usr/local/} by default) should now have the
593 necessary DLL and LIB files under the @file{bin} directory.
597 To use those files with MSVC++, do the same as you would do with
598 the static libraries, as described above. But in Step 4,
599 you should only need to add the directory where the LIB files are installed
600 (i.e. @file{c:\msys\usr\local\bin}). This is not a typo, the LIB files are
601 installed in the @file{bin} directory. And instead of adding @file{libxx.a}
602 files, you should add @file{avcodec.lib}, @file{avformat.lib}, and
603 @file{avutil.lib}. There should be no need for @file{libmingwex.a},
604 @file{libgcc.a}, and @file{wsock32.lib}, nor any other external library
605 statically linked into the DLLs. The @file{bin} directory contains a bunch
606 of DLL files, but the ones that are actually used to run your application
607 are the ones with a major version number in their filenames
608 (i.e. @file{avcodec-51.dll}).
610 @subsection Cross compilation for Windows with Linux
612 You must use the MinGW cross compilation tools available at
613 @url{http://www.mingw.org/}.
615 Then configure FFmpeg with the following options:
617 ./configure --target-os=mingw32 --cross-prefix=i386-mingw32msvc-
619 (you can change the cross-prefix according to the prefix chosen for the
622 Then you can easily test FFmpeg with Wine
623 (@url{http://www.winehq.com/}).
625 @subsection Compilation under Cygwin
627 The main issue with Cygwin is that newlib, its C library, does not
628 contain llrint(). However, it is possible to leverage the
629 implementation in MinGW.
631 Just install your Cygwin with all the "Base" packages, plus the
632 following "Devel" ones:
634 binutils, gcc-core, make, subversion, mingw-runtime
637 Do not install binutils-20060709-1 (they are buggy on shared builds);
638 use binutils-20050610-1 instead.
640 Then create a small library that just contains llrint():
643 ar x /usr/lib/mingw/libmingwex.a llrint.o
644 ar cq /usr/local/lib/libllrint.a llrint.o
650 ./configure --enable-static --disable-shared --extra-ldflags='-L /usr/local/lib' --extra-libs='-l llrint'
653 to make a static build or
656 ./configure --enable-shared --disable-static --extra-ldflags='-L /usr/local/lib' --extra-libs='-l llrint'
659 to build shared libraries.
661 If you want to build FFmpeg with additional libraries, download Cygwin
662 "Devel" packages for Ogg and Vorbis from any Cygwin packages repository
663 and/or SDL, xvid, faac, faad2 packages from Cygwin Ports,
664 (@url{http://cygwinports.dotsrc.org/}).
666 @subsection Crosscompilation for Windows under Cygwin
668 With Cygwin you can create Windows binaries that do not need the cygwin1.dll.
670 Just install your Cygwin as explained before, plus these additional
673 gcc-mingw-core, mingw-runtime, mingw-zlib
676 and add some special flags to your configure invocation.
678 For a static build run
680 ./configure --target-os=mingw32 --enable-memalign-hack --enable-static --disable-shared --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
683 and for a build with shared libraries
685 ./configure --target-os=mingw32 --enable-memalign-hack --enable-shared --disable-static --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
690 BeOS support is broken in mysterious ways.
694 For information about compiling FFmpeg on OS/2 see
695 @url{http://www.edm2.com/index.php/FFmpeg}.
697 @chapter Developers Guide
701 @item libavcodec is the library containing the codecs (both encoding and
702 decoding). Look at @file{libavcodec/apiexample.c} to see how to use it.
704 @item libavformat is the library containing the file format handling (mux and
705 demux code for several formats). Look at @file{ffplay.c} to use it in a
706 player. See @file{output_example.c} to use it to generate audio or video
711 @section Integrating libavcodec or libavformat in your program
713 You can integrate all the source code of the libraries to link them
714 statically to avoid any version problem. All you need is to provide a
715 'config.mak' and a 'config.h' in the parent directory. See the defines
716 generated by ./configure to understand what is needed.
718 You can use libavcodec or libavformat in your commercial program, but
719 @emph{any patch you make must be published}. The best way to proceed is
720 to send your patches to the FFmpeg mailing list.
723 @section Coding Rules
725 FFmpeg is programmed in the ISO C90 language with a few additional
726 features from ISO C99, namely:
729 the @samp{inline} keyword;
733 designated struct initializers (@samp{struct s x = @{ .i = 17 @};})
735 compound literals (@samp{x = (struct s) @{ 17, 23 @};})
738 These features are supported by all compilers we care about, so we will not
739 accept patches to remove their use unless they absolutely do not impair
740 clarity and performance.
742 All code must compile with GCC 2.95 and GCC 3.3. Currently, FFmpeg also
743 compiles with several other compilers, such as the Compaq ccc compiler
744 or Sun Studio 9, and we would like to keep it that way unless it would
745 be exceedingly involved. To ensure compatibility, please do not use any
746 additional C99 features or GCC extensions. Especially watch out for:
749 mixing statements and declarations;
751 @samp{long long} (use @samp{int64_t} instead);
753 @samp{__attribute__} not protected by @samp{#ifdef __GNUC__} or similar;
755 GCC statement expressions (@samp{(x = (@{ int y = 4; y; @})}).
759 The presentation is the one specified by 'indent -i4 -kr -nut'.
760 The TAB character is forbidden outside of Makefiles as is any
761 form of trailing whitespace. Commits containing either will be
762 rejected by the Subversion repository.
764 The main priority in FFmpeg is simplicity and small code size in order to
765 minimize the bug count.
767 Comments: Use the JavaDoc/Doxygen
768 format (see examples below) so that code documentation
769 can be generated automatically. All nontrivial functions should have a comment
770 above them explaining what the function does, even if it is just one sentence.
771 All structures and their member variables should be documented, too.
784 typedef struct Foobar@{
785 int var1; /**< var1 description */
786 int var2; ///< var2 description
787 /** var3 description */
795 * @@param my_parameter description of my_parameter
796 * @@return return value description
798 int myfunc(int my_parameter)
802 fprintf and printf are forbidden in libavformat and libavcodec,
803 please use av_log() instead.
805 Casts should be used only when necessary. Unneeded parentheses
806 should also be avoided if they don't make the code easier to understand.
808 @section Development Policy
812 Contributions should be licensed under the LGPL 2.1, including an
813 "or any later version" clause, or the MIT license. GPL 2 including
814 an "or any later version" clause is also acceptable, but LGPL is
817 You must not commit code which breaks FFmpeg! (Meaning unfinished but
818 enabled code which breaks compilation or compiles but does not work or
819 breaks the regression tests)
820 You can commit unfinished stuff (for testing etc), but it must be disabled
821 (#ifdef etc) by default so it does not interfere with other developers'
824 You do not have to over-test things. If it works for you, and you think it
825 should work for others, then commit. If your code has problems
826 (portability, triggers compiler bugs, unusual environment etc) they will be
827 reported and eventually fixed.
829 Do not commit unrelated changes together, split them into self-contained
830 pieces. Also do not forget that if part B depends on part A, but A does not
831 depend on B, then A can and should be committed first and separate from B.
832 Keeping changes well split into self-contained parts makes reviewing and
833 understanding them on the commit log mailing list easier. This also helps
834 in case of debugging later on.
835 Also if you have doubts about splitting or not splitting, do not hesitate to
836 ask/discuss it on the developer mailing list.
838 Do not change behavior of the program (renaming options etc) without
839 first discussing it on the ffmpeg-devel mailing list. Do not remove
840 functionality from the code. Just improve!
842 Note: Redundant code can be removed.
844 Do not commit changes to the build system (Makefiles, configure script)
845 which change behavior, defaults etc, without asking first. The same
846 applies to compiler warning fixes, trivial looking fixes and to code
847 maintained by other developers. We usually have a reason for doing things
848 the way we do. Send your changes as patches to the ffmpeg-devel mailing
849 list, and if the code maintainers say OK, you may commit. This does not
850 apply to files you wrote and/or maintain.
852 We refuse source indentation and other cosmetic changes if they are mixed
853 with functional changes, such commits will be rejected and removed. Every
854 developer has his own indentation style, you should not change it. Of course
855 if you (re)write something, you can use your own style, even though we would
856 prefer if the indentation throughout FFmpeg was consistent (Many projects
857 force a given indentation style - we do not.). If you really need to make
858 indentation changes (try to avoid this), separate them strictly from real
861 NOTE: If you had to put if()@{ .. @} over a large (> 5 lines) chunk of code,
862 then either do NOT change the indentation of the inner part within (do not
863 move it to the right)! or do so in a separate commit
865 Always fill out the commit log message. Describe in a few lines what you
866 changed and why. You can refer to mailing list postings if you fix a
867 particular bug. Comments such as "fixed!" or "Changed it." are unacceptable.
869 If you apply a patch by someone else, include the name and email address in
870 the log message. Since the ffmpeg-cvslog mailing list is publicly
871 archived you should add some SPAM protection to the email address. Send an
872 answer to ffmpeg-devel (or wherever you got the patch from) saying that
873 you applied the patch.
875 When applying patches that have been discussed (at length) on the mailing
876 list, reference the thread in the log message.
878 Do NOT commit to code actively maintained by others without permission.
879 Send a patch to ffmpeg-devel instead. If no one answers within a reasonable
880 timeframe (12h for build failures and security fixes, 3 days small changes,
881 1 week for big patches) then commit your patch if you think it is OK.
882 Also note, the maintainer can simply ask for more time to review!
884 Subscribe to the ffmpeg-cvslog mailing list. The diffs of all commits
885 are sent there and reviewed by all the other developers. Bugs and possible
886 improvements or general questions regarding commits are discussed there. We
887 expect you to react if problems with your code are uncovered.
889 Update the documentation if you change behavior or add features. If you are
890 unsure how best to do this, send a patch to ffmpeg-devel, the documentation
891 maintainer(s) will review and commit your stuff.
893 Try to keep important discussions and requests (also) on the public
894 developer mailing list, so that all developers can benefit from them.
896 Never write to unallocated memory, never write over the end of arrays,
897 always check values read from some untrusted source before using them
898 as array index or other risky things.
900 Remember to check if you need to bump versions for the specific libav
901 parts (libavutil, libavcodec, libavformat) you are changing. You need
902 to change the version integer.
903 Incrementing the first component means no backward compatibility to
904 previous versions (e.g. removal of a function from the public API).
905 Incrementing the second component means backward compatible change
906 (e.g. addition of a function to the public API or extension of an
907 existing data structure).
908 Incrementing the third component means a noteworthy binary compatible
909 change (e.g. encoder bug fix that matters for the decoder).
911 Compiler warnings indicate potential bugs or code with bad style. If a type of
912 warning always points to correct and clean code, that warning should
913 be disabled, not the code changed.
914 Thus the remaining warnings can either be bugs or correct code.
915 If it is a bug, the bug has to be fixed. If it is not, the code should
916 be changed to not generate a warning unless that causes a slowdown
917 or obfuscates the code.
919 If you add a new file, give it a proper license header. Do not copy and
920 paste it from a random place, use an existing file as template.
923 We think our rules are not too hard. If you have comments, contact us.
925 Note, these rules are mostly borrowed from the MPlayer project.
927 @section Submitting patches
929 First, (@pxref{Coding Rules}) above if you did not yet.
931 When you submit your patch, try to send a unified diff (diff '-up'
932 option). We cannot read other diffs :-)
934 Also please do not submit a patch which contains several unrelated changes.
935 Split it into separate, self-contained pieces. This does not mean splitting
936 file by file. Instead, make the patch as small as possible while still
937 keeping it as a logical unit that contains an individual change, even
938 if it spans multiple files. This makes reviewing your patches much easier
939 for us and greatly increases your chances of getting your patch applied.
941 Run the regression tests before submitting a patch so that you can
942 verify that there are no big problems.
944 Patches should be posted as base64 encoded attachments (or any other
945 encoding which ensures that the patch will not be trashed during
946 transmission) to the ffmpeg-devel mailing list, see
947 @url{http://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel}
949 It also helps quite a bit if you tell us what the patch does (for example
950 'replaces lrint by lrintf'), and why (for example '*BSD isn't C99 compliant
953 Also please if you send several patches, send each patch as a separate mail,
954 do not attach several unrelated patches to the same mail.
956 @section New codecs or formats checklist
960 Did you use av_cold for codec initialization and close functions?
962 Did you add a long_name under NULL_IF_CONFIG_SMALL to the AVCodec or
963 AVInputFormat/AVOutputFormat struct?
965 Did you bump the minor version number in @file{avcodec.h} or
968 Did you register it in @file{allcodecs.c} or @file{allformats.c}?
970 Did you add the CodecID to @file{avcodec.h}?
972 If it has a fourcc, did you add it to @file{libavformat/riff.c},
973 even if it is only a decoder?
975 Did you add a rule to compile the appropriate files in the Makefile?
976 Remember to do this even if you're just adding a format to a file that is
977 already being compiled by some other rule, like a raw demuxer.
979 Did you add an entry to the table of supported formats or codecs in the
982 Did you add an entry in the Changelog?
984 If it depends on a parser or a library, did you add that dependency in
987 Did you "svn add" the appropriate files before commiting?
990 @section patch submission checklist
994 Do the regression tests pass with the patch applied?
996 Is the patch a unified diff?
998 Is the patch against latest FFmpeg SVN?
1000 Are you subscribed to ffmpeg-dev?
1001 (the list is subscribers only due to spam)
1003 Have you checked that the changes are minimal, so that the same cannot be
1004 achieved with a smaller patch and/or simpler final code?
1006 If the change is to speed critical code, did you benchmark it?
1008 If you did any benchmarks, did you provide them in the mail?
1010 Have you checked that the patch does not introduce buffer overflows or
1011 other security issues?
1013 If you add a new demuxer or decoder, have you checked that it does not
1014 crash with damaged input (see tools/trasher)?
1016 Is the patch created from the root of the source tree, so it can be
1017 applied with @code{patch -p0}?
1019 Does the patch not mix functional and cosmetic changes?
1021 Did you add tabs or trailing whitespace to the code? Both are forbidden.
1023 Is the patch attached to the email you send?
1025 Is the mime type of the patch correct? It should be text/x-diff or
1026 text/x-patch or at least text/plain and not application/octet-stream.
1028 If the patch fixes a bug, did you provide a verbose analysis of the bug?
1030 If the patch fixes a bug, did you provide enough information, including
1031 a sample, so the bug can be reproduced and the fix can be verified?
1032 Note please do not attach samples >100k to mails but rather provide a
1033 URL, you can upload to ftp://upload.mplayerhq.hu
1035 Did you provide a verbose summary about what the patch does change?
1037 Did you provide a verbose explanation why it changes things like it does?
1039 Did you provide a verbose summary of the user visible advantages and
1040 disadvantages if the patch is applied?
1042 Did you provide an example so we can verify the new feature added by the
1045 If you added a new file, did you insert a license header? It should be
1046 taken from FFmpeg, not randomly copied and pasted from somewhere else.
1048 You should maintain alphabetical order in alphabetically ordered lists as
1049 long as doing so does not break API/ABI compatibility.
1051 Lines with similar content should be aligned vertically when doing so
1052 improves readability.
1054 Did you provide a suggestion for a clear commit log message?
1056 Did you test your decoder or demuxer against damaged data? If no, see
1057 tools/trasher and the noise bitstream filter. Your decoder or demuxer
1058 should not crash or end in a (near) infinite loop when fed damaged data.
1061 @section Patch review process
1063 All patches posted to ffmpeg-devel will be reviewed, unless they contain a
1064 clear note that the patch is not for SVN.
1065 Reviews and comments will be posted as replies to the patch on the
1066 mailing list. The patch submitter then has to take care of every comment,
1067 that can be by resubmitting a changed patch or by discussion. Resubmitted
1068 patches will themselves be reviewed like any other patch. If at some point
1069 a patch passes review with no comments then it is approved, that can for
1070 simple and small patches happen immediately while large patches will generally
1071 have to be changed and reviewed many times before they are approved.
1072 After a patch is approved it will be committed to the repository.
1074 We will review all submitted patches, but sometimes we are quite busy so
1075 especially for large patches this can take several weeks.
1077 When resubmitting patches, please do not make any significant changes
1078 not related to the comments received during review. Such patches will
1079 be rejected. Instead, submit significant changes or new features as
1082 @section Regression tests
1084 Before submitting a patch (or committing to the repository), you should at least
1085 test that you did not break anything.
1087 The regression tests build a synthetic video stream and a synthetic
1088 audio stream. These are then encoded and decoded with all codecs or
1089 formats. The CRC (or MD5) of each generated file is recorded in a
1090 result file. A 'diff' is launched to compare the reference results and
1093 The regression tests then go on to test the FFserver code with a
1094 limited set of streams. It is important that this step runs correctly
1097 Run 'make test' to test all the codecs and formats.
1099 Run 'make fulltest' to test all the codecs, formats and FFserver.
1101 [Of course, some patches may change the results of the regression tests. In
1102 this case, the reference results of the regression tests shall be modified