1 \input texinfo @c -*- texinfo -*-
3 @settitle General Documentation
6 @center @titlefont{General Documentation}
11 @chapter external libraries
13 FFmpeg can be hooked up with a number of external libraries to add support
14 for more formats. None of them are used by default, their use has to be
15 explicitly requested by passing the appropriate flags to @file{./configure}.
19 AMR comes in two different flavors, wideband and narrowband. FFmpeg can make
20 use of the AMR wideband (floating-point mode) and the AMR narrowband
21 (floating-point mode) reference decoders and encoders.
23 Go to @url{http://www.penguin.cz/~utx/amr} and follow the instructions for
24 installing the libraries. Then pass @code{--enable-libamr-nb} and/or
25 @code{--enable-libamr-wb} to configure to enable the libraries.
27 Note that libamr is copyrighted without any sort of license grant. This means
28 that you can use it if you legally obtained it but you are not allowed to
29 redistribute it in any way. @strong{Any FFmpeg binaries with libamr support
30 you create are non-free and unredistributable!}
33 @chapter Supported File Formats and Codecs
35 You can use the @code{-formats} option to have an exhaustive list.
39 FFmpeg supports the following file formats through the @code{libavformat}
42 @multitable @columnfractions .4 .1 .1 .4
43 @item Name @tab Encoding @tab Decoding @tab Comments
45 @tab 4X Technologies format, used in some games.
46 @item 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 X @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 Name @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 Name @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 Name @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 @item AMR-NB @tab X @tab X
343 @tab Supported through an external library.
344 @item AMR-WB @tab X @tab X
345 @tab Supported through an external library.
346 @item AMV IMA ADPCM @tab @tab X
347 @tab Used in AMV files
348 @item Apple lossless audio @tab X @tab X
349 @tab QuickTime fourcc 'alac'
350 @item Apple MACE 3 @tab @tab X
351 @item Apple MACE 6 @tab @tab X
352 @item ATRAC 3 @tab @tab X
353 @item CD-ROM XA ADPCM @tab @tab X
354 @item Cin audio @tab @tab X
355 @tab Codec used in Delphine Software International games.
356 @item Creative ADPCM @tab @tab X
357 @tab 16 -> 4, 8 -> 4, 8 -> 3, 8 -> 2
358 @item CRI ADX ADPCM @tab X @tab X
359 @tab Used in Sega Dreamcast games.
360 @item DSP Group TrueSpeech @tab @tab X
361 @item DTS Coherent Audio @tab @tab X
362 @item Duck DK3 IMA ADPCM @tab @tab X
363 @tab Used in some Sega Saturn console games.
364 @item Duck DK4 IMA ADPCM @tab @tab X
365 @tab Used in some Sega Saturn console games.
366 @item DV audio @tab @tab X
367 @item Electronic Arts ADPCM @tab @tab X
368 @tab Used in various EA titles.
369 @item Enhanced AC-3 @tab @tab X
370 @item FLAC lossless audio @tab IX @tab X
371 @item G.726 ADPCM @tab X @tab X
372 @item id RoQ DPCM @tab X @tab X
373 @tab Used in Quake III, Jedi Knight 2, other computer games.
374 @item Intel Music Coder @tab @tab X
375 @item Interplay MVE DPCM @tab @tab X
376 @tab Used in various Interplay computer games.
377 @item MAXIS EA ADPCM @tab @tab X
378 @tab Used in Sim City 3000.
379 @item Microsoft ADPCM @tab X @tab X
380 @item MLP/TrueHD @tab @tab X
381 @tab Used in DVD-Audio and Blu-Ray discs.
382 @item Monkey's Audio @tab @tab X
383 @tab Only versions 3.97-3.99 are supported.
384 @item MPEG audio layer 1/3 @tab X @tab IX
385 @tab MP3 encoding is supported through the external library LAME.
386 @item MPEG audio layer 2 @tab IX @tab IX
387 @item MS IMA ADPCM @tab X @tab X
388 @item Musepack @tab @tab X
389 @tab SV7 and SV8 are supported.
390 @item Nellymoser ASAO @tab X @tab X
391 @item Qdesign QDM2 @tab @tab X
392 @tab There are still some distortions.
393 @item QT IMA ADPCM @tab X @tab X
394 @item RA144 @tab @tab X
395 @tab Real 14400 bit/s codec
396 @item RA288 @tab @tab X
397 @tab Real 28800 bit/s codec
398 @item RADnet @tab IX @tab IX
399 @tab Real low bitrate AC-3 codec
400 @item Real COOK @tab @tab X
401 @tab All versions except 5.1 are supported.
402 @item Shorten @tab @tab X
403 @item Sierra Online DPCM @tab @tab X
404 @tab Used in Sierra Online game audio files.
405 @item Smacker audio @tab @tab X
406 @item SMJPEG IMA ADPCM @tab @tab X
407 @tab Used in certain Loki game ports.
408 @item Sonic @tab X @tab X
409 @tab experimental codec
410 @item Sonic lossless @tab X @tab X
411 @tab experimental codec
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://ffmpeg.arrozcru.org/}.
442 @subsection Native Windows compilation
444 FFmpeg can be built to run natively on Windows using the MinGW tools. Install
445 the latest versions of MSYS and MinGW from @url{http://www.mingw.org/}.
446 You can find detailed installation
447 instructions in the download section and the FAQ.
449 FFmpeg does not build out-of-the-box with the packages the automated MinGW
450 installer provides. It also requires coreutils to be installed and many other
451 packages updated to the latest version. The minimum version for some packages
456 @item msys-make 3.81-2 (note: not mingw32-make)
458 @item mingw-runtime 3.15
461 You will also need to pass @code{-fno-common} to the compiler to work around
462 a GCC bug (see @url{http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37216}).
464 Within the MSYS shell, configure and make with:
467 ./configure --enable-memalign-hack --extra-cflags=-fno-common
472 This will install @file{ffmpeg.exe} along with many other development files
473 to @file{/usr/local}. You may specify another install path using the
474 @code{--prefix} option in @file{configure}.
480 @item In order to compile vhooks, you must have a POSIX-compliant libdl in
481 your MinGW system. Get dlfcn-win32 from
482 @url{http://code.google.com/p/dlfcn-win32}.
484 @item In order to compile FFplay, you must have the MinGW development library
485 of SDL. Get it from @url{http://www.libsdl.org}.
486 Edit the @file{bin/sdl-config} script so that it points to the correct prefix
487 where SDL was installed. Verify that @file{sdl-config} can be launched from
488 the MSYS command line.
490 @item By using @code{./configure --enable-shared} when configuring FFmpeg,
491 you can build libavutil, libavcodec and libavformat as DLLs.
495 @subsection Microsoft Visual C++ compatibility
497 As stated in the FAQ, FFmpeg will not compile under MSVC++. However, if you
498 want to use the libav* libraries in your own applications, you can still
499 compile those applications using MSVC++. But the libav* libraries you link
500 to @emph{must} be built with MinGW. However, you will not be able to debug
501 inside the libav* libraries, since MSVC++ does not recognize the debug
502 symbols generated by GCC.
503 We strongly recommend you to move over from MSVC++ to MinGW tools.
505 This description of how to use the FFmpeg libraries with MSVC++ is based on
506 Microsoft Visual C++ 2005 Express Edition. If you have a different version,
507 you might have to modify the procedures slightly.
509 @subsubsection Using static libraries
511 Assuming you have just built and installed FFmpeg in @file{/usr/local}.
515 @item Create a new console application ("File / New / Project") and then
516 select "Win32 Console Application". On the appropriate page of the
517 Application Wizard, uncheck the "Precompiled headers" option.
519 @item Write the source code for your application, or, for testing, just
520 copy the code from an existing sample application into the source file
521 that MSVC++ has already created for you. For example, you can copy
522 @file{output_example.c} from the FFmpeg distribution.
524 @item Open the "Project / Properties" dialog box. In the "Configuration"
525 combo box, select "All Configurations" so that the changes you make will
526 affect both debug and release builds. In the tree view on the left hand
527 side, select "C/C++ / General", then edit the "Additional Include
528 Directories" setting to contain the path where the FFmpeg includes were
529 installed (i.e. @file{c:\msys\1.0\local\include}).
530 Do not add MinGW's include directory here, or the include files will
531 conflict with MSVC's.
533 @item Still in the "Project / Properties" dialog box, select
534 "Linker / General" from the tree view and edit the
535 "Additional Library Directories" setting to contain the @file{lib}
536 directory where FFmpeg was installed (i.e. @file{c:\msys\1.0\local\lib}),
537 the directory where MinGW libs are installed (i.e. @file{c:\mingw\lib}),
538 and the directory where MinGW's GCC libs are installed
539 (i.e. @file{C:\mingw\lib\gcc\mingw32\4.2.1-sjlj}). Then select
540 "Linker / Input" from the tree view, and add the files @file{libavformat.a},
541 @file{libavcodec.a}, @file{libavutil.a}, @file{libmingwex.a},
542 @file{libgcc.a}, and any other libraries you used (i.e. @file{libz.a})
543 to the end of "Additional Dependencies".
545 @item Now, select "C/C++ / Code Generation" from the tree view. Select
546 "Debug" in the "Configuration" combo box. Make sure that "Runtime
547 Library" is set to "Multi-threaded Debug DLL". Then, select "Release" in
548 the "Configuration" combo box and make sure that "Runtime Library" is
549 set to "Multi-threaded DLL".
551 @item Click "OK" to close the "Project / Properties" dialog box.
553 @item MSVC++ lacks some C99 header files that are fundamental for FFmpeg.
554 Get msinttypes from @url{http://code.google.com/p/msinttypes/downloads/list}
555 and install it in MSVC++'s include directory
556 (i.e. @file{C:\Program Files\Microsoft Visual Studio 8\VC\include}).
558 @item MSVC++ also does not understand the @code{inline} keyword used by
559 FFmpeg, so you must add this line before @code{#include}ing libav*:
561 #define inline _inline
564 @item Build your application, everything should work.
568 @subsubsection Using shared libraries
570 This is how to create DLL and LIB files that are compatible with MSVC++:
574 @item Add a call to @file{vcvars32.bat} (which sets up the environment
575 variables for the Visual C++ tools) as the first line of @file{msys.bat}.
576 The standard location for @file{vcvars32.bat} is
577 @file{C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat},
578 and the standard location for @file{msys.bat} is @file{C:\msys\1.0\msys.bat}.
579 If this corresponds to your setup, add the following line as the first line
583 call "C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat"
586 Alternatively, you may start the @file{Visual Studio 2005 Command Prompt},
587 and run @file{c:\msys\1.0\msys.bat} from there.
589 @item Within the MSYS shell, run @code{lib.exe}. If you get a help message
590 from @file{Microsoft (R) Library Manager}, this means your environment
591 variables are set up correctly, the @file{Microsoft (R) Library Manager}
592 is on the path and will be used by FFmpeg to create
593 MSVC++-compatible import libraries.
595 @item Build FFmpeg with
598 ./configure --enable-shared --enable-memalign-hack
603 Your install path (@file{/usr/local/} by default) should now have the
604 necessary DLL and LIB files under the @file{bin} directory.
608 To use those files with MSVC++, do the same as you would do with
609 the static libraries, as described above. But in Step 4,
610 you should only need to add the directory where the LIB files are installed
611 (i.e. @file{c:\msys\usr\local\bin}). This is not a typo, the LIB files are
612 installed in the @file{bin} directory. And instead of adding @file{libxx.a}
613 files, you should add @file{avcodec.lib}, @file{avformat.lib}, and
614 @file{avutil.lib}. There should be no need for @file{libmingwex.a},
615 @file{libgcc.a}, and @file{wsock32.lib}, nor any other external library
616 statically linked into the DLLs. The @file{bin} directory contains a bunch
617 of DLL files, but the ones that are actually used to run your application
618 are the ones with a major version number in their filenames
619 (i.e. @file{avcodec-51.dll}).
621 @subsection Cross compilation for Windows with Linux
623 You must use the MinGW cross compilation tools available at
624 @url{http://www.mingw.org/}.
626 Then configure FFmpeg with the following options:
628 ./configure --target-os=mingw32 --cross-prefix=i386-mingw32msvc-
630 (you can change the cross-prefix according to the prefix chosen for the
633 Then you can easily test FFmpeg with Wine
634 (@url{http://www.winehq.com/}).
636 @subsection Compilation under Cygwin
638 The main issue with Cygwin is that newlib, its C library, does not
639 contain llrint(). However, it is possible to leverage the
640 implementation in MinGW.
642 Just install your Cygwin with all the "Base" packages, plus the
643 following "Devel" ones:
645 binutils, gcc-core, make, subversion, mingw-runtime
648 Do not install binutils-20060709-1 (they are buggy on shared builds);
649 use binutils-20050610-1 instead.
651 Then create a small library that just contains llrint():
654 ar x /usr/lib/mingw/libmingwex.a llrint.o
655 ar cq /usr/local/lib/libllrint.a llrint.o
661 ./configure --enable-static --disable-shared --extra-ldflags='-L /usr/local/lib' --extra-libs='-l llrint'
664 to make a static build or
667 ./configure --enable-shared --disable-static --extra-ldflags='-L /usr/local/lib' --extra-libs='-l llrint'
670 to build shared libraries.
672 If you want to build FFmpeg with additional libraries, download Cygwin
673 "Devel" packages for Ogg and Vorbis from any Cygwin packages repository
674 and/or SDL, xvid, faac, faad2 packages from Cygwin Ports,
675 (@url{http://cygwinports.dotsrc.org/}).
677 @subsection Crosscompilation for Windows under Cygwin
679 With Cygwin you can create Windows binaries that do not need the cygwin1.dll.
681 Just install your Cygwin as explained before, plus these additional
684 gcc-mingw-core, mingw-runtime, mingw-zlib
687 and add some special flags to your configure invocation.
689 For a static build run
691 ./configure --target-os=mingw32 --enable-memalign-hack --enable-static --disable-shared --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
694 and for a build with shared libraries
696 ./configure --target-os=mingw32 --enable-memalign-hack --enable-shared --disable-static --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
701 BeOS support is broken in mysterious ways.
705 For information about compiling FFmpeg on OS/2 see
706 @url{http://www.edm2.com/index.php/FFmpeg}.
708 @chapter Developers Guide
712 @item libavcodec is the library containing the codecs (both encoding and
713 decoding). Look at @file{libavcodec/apiexample.c} to see how to use it.
715 @item libavformat is the library containing the file format handling (mux and
716 demux code for several formats). Look at @file{ffplay.c} to use it in a
717 player. See @file{output_example.c} to use it to generate audio or video
722 @section Integrating libavcodec or libavformat in your program
724 You can integrate all the source code of the libraries to link them
725 statically to avoid any version problem. All you need is to provide a
726 'config.mak' and a 'config.h' in the parent directory. See the defines
727 generated by ./configure to understand what is needed.
729 You can use libavcodec or libavformat in your commercial program, but
730 @emph{any patch you make must be published}. The best way to proceed is
731 to send your patches to the FFmpeg mailing list.
734 @section Coding Rules
736 FFmpeg is programmed in the ISO C90 language with a few additional
737 features from ISO C99, namely:
740 the @samp{inline} keyword;
744 designated struct initializers (@samp{struct s x = @{ .i = 17 @};})
746 compound literals (@samp{x = (struct s) @{ 17, 23 @};})
749 These features are supported by all compilers we care about, so we will not
750 accept patches to remove their use unless they absolutely do not impair
751 clarity and performance.
753 All code must compile with GCC 2.95 and GCC 3.3. Currently, FFmpeg also
754 compiles with several other compilers, such as the Compaq ccc compiler
755 or Sun Studio 9, and we would like to keep it that way unless it would
756 be exceedingly involved. To ensure compatibility, please do not use any
757 additional C99 features or GCC extensions. Especially watch out for:
760 mixing statements and declarations;
762 @samp{long long} (use @samp{int64_t} instead);
764 @samp{__attribute__} not protected by @samp{#ifdef __GNUC__} or similar;
766 GCC statement expressions (@samp{(x = (@{ int y = 4; y; @})}).
770 The presentation is the one specified by 'indent -i4 -kr -nut'.
771 The TAB character is forbidden outside of Makefiles as is any
772 form of trailing whitespace. Commits containing either will be
773 rejected by the Subversion repository.
775 The main priority in FFmpeg is simplicity and small code size in order to
776 minimize the bug count.
778 Comments: Use the JavaDoc/Doxygen
779 format (see examples below) so that code documentation
780 can be generated automatically. All nontrivial functions should have a comment
781 above them explaining what the function does, even if it is just one sentence.
782 All structures and their member variables should be documented, too.
795 typedef struct Foobar@{
796 int var1; /**< var1 description */
797 int var2; ///< var2 description
798 /** var3 description */
806 * @@param my_parameter description of my_parameter
807 * @@return return value description
809 int myfunc(int my_parameter)
813 fprintf and printf are forbidden in libavformat and libavcodec,
814 please use av_log() instead.
816 Casts should be used only when necessary. Unneeded parentheses
817 should also be avoided if they don't make the code easier to understand.
819 @section Development Policy
823 Contributions should be licensed under the LGPL 2.1, including an
824 "or any later version" clause, or the MIT license. GPL 2 including
825 an "or any later version" clause is also acceptable, but LGPL is
828 You must not commit code which breaks FFmpeg! (Meaning unfinished but
829 enabled code which breaks compilation or compiles but does not work or
830 breaks the regression tests)
831 You can commit unfinished stuff (for testing etc), but it must be disabled
832 (#ifdef etc) by default so it does not interfere with other developers'
835 You do not have to over-test things. If it works for you, and you think it
836 should work for others, then commit. If your code has problems
837 (portability, triggers compiler bugs, unusual environment etc) they will be
838 reported and eventually fixed.
840 Do not commit unrelated changes together, split them into self-contained
841 pieces. Also do not forget that if part B depends on part A, but A does not
842 depend on B, then A can and should be committed first and separate from B.
843 Keeping changes well split into self-contained parts makes reviewing and
844 understanding them on the commit log mailing list easier. This also helps
845 in case of debugging later on.
846 Also if you have doubts about splitting or not splitting, do not hesitate to
847 ask/discuss it on the developer mailing list.
849 Do not change behavior of the program (renaming options etc) without
850 first discussing it on the ffmpeg-devel mailing list. Do not remove
851 functionality from the code. Just improve!
853 Note: Redundant code can be removed.
855 Do not commit changes to the build system (Makefiles, configure script)
856 which change behavior, defaults etc, without asking first. The same
857 applies to compiler warning fixes, trivial looking fixes and to code
858 maintained by other developers. We usually have a reason for doing things
859 the way we do. Send your changes as patches to the ffmpeg-devel mailing
860 list, and if the code maintainers say OK, you may commit. This does not
861 apply to files you wrote and/or maintain.
863 We refuse source indentation and other cosmetic changes if they are mixed
864 with functional changes, such commits will be rejected and removed. Every
865 developer has his own indentation style, you should not change it. Of course
866 if you (re)write something, you can use your own style, even though we would
867 prefer if the indentation throughout FFmpeg was consistent (Many projects
868 force a given indentation style - we do not.). If you really need to make
869 indentation changes (try to avoid this), separate them strictly from real
872 NOTE: If you had to put if()@{ .. @} over a large (> 5 lines) chunk of code,
873 then either do NOT change the indentation of the inner part within (do not
874 move it to the right)! or do so in a separate commit
876 Always fill out the commit log message. Describe in a few lines what you
877 changed and why. You can refer to mailing list postings if you fix a
878 particular bug. Comments such as "fixed!" or "Changed it." are unacceptable.
880 If you apply a patch by someone else, include the name and email address in
881 the log message. Since the ffmpeg-cvslog mailing list is publicly
882 archived you should add some SPAM protection to the email address. Send an
883 answer to ffmpeg-devel (or wherever you got the patch from) saying that
884 you applied the patch.
886 When applying patches that have been discussed (at length) on the mailing
887 list, reference the thread in the log message.
889 Do NOT commit to code actively maintained by others without permission.
890 Send a patch to ffmpeg-devel instead. If no one answers within a reasonable
891 timeframe (12h for build failures and security fixes, 3 days small changes,
892 1 week for big patches) then commit your patch if you think it is OK.
893 Also note, the maintainer can simply ask for more time to review!
895 Subscribe to the ffmpeg-cvslog mailing list. The diffs of all commits
896 are sent there and reviewed by all the other developers. Bugs and possible
897 improvements or general questions regarding commits are discussed there. We
898 expect you to react if problems with your code are uncovered.
900 Update the documentation if you change behavior or add features. If you are
901 unsure how best to do this, send a patch to ffmpeg-devel, the documentation
902 maintainer(s) will review and commit your stuff.
904 Try to keep important discussions and requests (also) on the public
905 developer mailing list, so that all developers can benefit from them.
907 Never write to unallocated memory, never write over the end of arrays,
908 always check values read from some untrusted source before using them
909 as array index or other risky things.
911 Remember to check if you need to bump versions for the specific libav
912 parts (libavutil, libavcodec, libavformat) you are changing. You need
913 to change the version integer.
914 Incrementing the first component means no backward compatibility to
915 previous versions (e.g. removal of a function from the public API).
916 Incrementing the second component means backward compatible change
917 (e.g. addition of a function to the public API or extension of an
918 existing data structure).
919 Incrementing the third component means a noteworthy binary compatible
920 change (e.g. encoder bug fix that matters for the decoder).
922 Compiler warnings indicate potential bugs or code with bad style. If a type of
923 warning always points to correct and clean code, that warning should
924 be disabled, not the code changed.
925 Thus the remaining warnings can either be bugs or correct code.
926 If it is a bug, the bug has to be fixed. If it is not, the code should
927 be changed to not generate a warning unless that causes a slowdown
928 or obfuscates the code.
930 If you add a new file, give it a proper license header. Do not copy and
931 paste it from a random place, use an existing file as template.
934 We think our rules are not too hard. If you have comments, contact us.
936 Note, these rules are mostly borrowed from the MPlayer project.
938 @section Submitting patches
940 First, (@pxref{Coding Rules}) above if you did not yet.
942 When you submit your patch, try to send a unified diff (diff '-up'
943 option). We cannot read other diffs :-)
945 Also please do not submit a patch which contains several unrelated changes.
946 Split it into separate, self-contained pieces. This does not mean splitting
947 file by file. Instead, make the patch as small as possible while still
948 keeping it as a logical unit that contains an individual change, even
949 if it spans multiple files. This makes reviewing your patches much easier
950 for us and greatly increases your chances of getting your patch applied.
952 Run the regression tests before submitting a patch so that you can
953 verify that there are no big problems.
955 Patches should be posted as base64 encoded attachments (or any other
956 encoding which ensures that the patch will not be trashed during
957 transmission) to the ffmpeg-devel mailing list, see
958 @url{http://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel}
960 It also helps quite a bit if you tell us what the patch does (for example
961 'replaces lrint by lrintf'), and why (for example '*BSD isn't C99 compliant
964 Also please if you send several patches, send each patch as a separate mail,
965 do not attach several unrelated patches to the same mail.
967 @section New codecs or formats checklist
971 Did you use av_cold for codec initialization and close functions?
973 Did you add a long_name under NULL_IF_CONFIG_SMALL to the AVCodec or
974 AVInputFormat/AVOutputFormat struct?
976 Did you bump the minor version number in @file{avcodec.h} or
979 Did you register it in @file{allcodecs.c} or @file{allformats.c}?
981 Did you add the CodecID to @file{avcodec.h}?
983 If it has a fourcc, did you add it to @file{libavformat/riff.c},
984 even if it is only a decoder?
986 Did you add a rule to compile the appropriate files in the Makefile?
987 Remember to do this even if you're just adding a format to a file that is
988 already being compiled by some other rule, like a raw demuxer.
990 Did you add an entry to the table of supported formats or codecs in the
993 Did you add an entry in the Changelog?
995 If it depends on a parser or a library, did you add that dependency in
998 Did you "svn add" the appropriate files before commiting?
1001 @section patch submission checklist
1005 Do the regression tests pass with the patch applied?
1007 Is the patch a unified diff?
1009 Is the patch against latest FFmpeg SVN?
1011 Are you subscribed to ffmpeg-dev?
1012 (the list is subscribers only due to spam)
1014 Have you checked that the changes are minimal, so that the same cannot be
1015 achieved with a smaller patch and/or simpler final code?
1017 If the change is to speed critical code, did you benchmark it?
1019 If you did any benchmarks, did you provide them in the mail?
1021 Have you checked that the patch does not introduce buffer overflows or
1022 other security issues?
1024 If you add a new demuxer or decoder, have you checked that it does not
1025 crash with damaged input (see tools/trasher)?
1027 Is the patch created from the root of the source tree, so it can be
1028 applied with @code{patch -p0}?
1030 Does the patch not mix functional and cosmetic changes?
1032 Did you add tabs or trailing whitespace to the code? Both are forbidden.
1034 Is the patch attached to the email you send?
1036 Is the mime type of the patch correct? It should be text/x-diff or
1037 text/x-patch or at least text/plain and not application/octet-stream.
1039 If the patch fixes a bug, did you provide a verbose analysis of the bug?
1041 If the patch fixes a bug, did you provide enough information, including
1042 a sample, so the bug can be reproduced and the fix can be verified?
1043 Note please do not attach samples >100k to mails but rather provide a
1044 URL, you can upload to ftp://upload.mplayerhq.hu
1046 Did you provide a verbose summary about what the patch does change?
1048 Did you provide a verbose explanation why it changes things like it does?
1050 Did you provide a verbose summary of the user visible advantages and
1051 disadvantages if the patch is applied?
1053 Did you provide an example so we can verify the new feature added by the
1056 If you added a new file, did you insert a license header? It should be
1057 taken from FFmpeg, not randomly copied and pasted from somewhere else.
1059 You should maintain alphabetical order in alphabetically ordered lists as
1060 long as doing so does not break API/ABI compatibility.
1062 Lines with similar content should be aligned vertically when doing so
1063 improves readability.
1065 Did you provide a suggestion for a clear commit log message?
1067 Did you test your decoder or demuxer against damaged data? If no, see
1068 tools/trasher and the noise bitstream filter. Your decoder or demuxer
1069 should not crash or end in a (near) infinite loop when fed damaged data.
1072 @section Patch review process
1074 All patches posted to ffmpeg-devel will be reviewed, unless they contain a
1075 clear note that the patch is not for SVN.
1076 Reviews and comments will be posted as replies to the patch on the
1077 mailing list. The patch submitter then has to take care of every comment,
1078 that can be by resubmitting a changed patch or by discussion. Resubmitted
1079 patches will themselves be reviewed like any other patch. If at some point
1080 a patch passes review with no comments then it is approved, that can for
1081 simple and small patches happen immediately while large patches will generally
1082 have to be changed and reviewed many times before they are approved.
1083 After a patch is approved it will be committed to the repository.
1085 We will review all submitted patches, but sometimes we are quite busy so
1086 especially for large patches this can take several weeks.
1088 When resubmitting patches, please do not make any significant changes
1089 not related to the comments received during review. Such patches will
1090 be rejected. Instead, submit significant changes or new features as
1093 @section Regression tests
1095 Before submitting a patch (or committing to the repository), you should at least
1096 test that you did not break anything.
1098 The regression tests build a synthetic video stream and a synthetic
1099 audio stream. These are then encoded and decoded with all codecs or
1100 formats. The CRC (or MD5) of each generated file is recorded in a
1101 result file. A 'diff' is launched to compare the reference results and
1104 The regression tests then go on to test the FFserver code with a
1105 limited set of streams. It is important that this step runs correctly
1108 Run 'make test' to test all the codecs and formats.
1110 Run 'make fulltest' to test all the codecs, formats and FFserver.
1112 [Of course, some patches may change the results of the regression tests. In
1113 this case, the reference results of the regression tests shall be modified