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 ASF @tab X @tab X
48 @item AVI @tab X @tab X
49 @item AVM2 (Flash 9) @tab X @tab X
50 @tab Only embedded audio is decoded.
52 @tab Multimedia format used by the Creature Shock game.
53 @item American Laser Games MM @tab @tab X
54 @tab Multimedia format used in games like Mad Dog McCree.
56 @tab Brute Force & Ignorance, used in Flash Traffic: City of Angels.
57 @item Bethsoft VID @tab @tab X
58 @tab Used in some games from Bethesda Softworks.
60 @tab Used in the game Cyberia from Interplay.
62 @tab Multimedia format used by Delphine Software games.
63 @item CRYO APC @tab @tab X
64 @tab Audio format used in some games by CRYO Interactive Entertainment.
65 @item Creative VOC @tab X @tab X
66 @tab Created for the Sound Blaster Pro.
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
81 @tab Interchange File Format
82 @item Interplay MVE @tab @tab X
83 @tab Format used in various Interplay computer games.
84 @item LMLM4 @tab @tab X
85 @tab Used by Linux Media Labs MPEG-4 PCI boards
86 @item MAXIS EA XA @tab @tab X
87 @tab Used in Sim City 3000; file extension .xa.
88 @item MPEG audio @tab X @tab X
89 @item MPEG-1 systems @tab X @tab X
90 @tab muxed audio and video
91 @item MPEG-2 PS @tab X @tab X
92 @tab also known as @code{VOB} file
93 @item MPEG-2 TS @tab @tab X
94 @tab also known as DVB Transport Stream
95 @item MPEG-4 @tab X @tab X
96 @tab MPEG-4 is a variant of QuickTime.
97 @item MSN TCP Webcam @tab @tab X
98 @tab Used by MSN Messenger Webcam streams.
100 @tab Material eXchange Format SMPTE 377M, used by D-Cinema, broadcast industry.
101 @item Macromedia Flash @tab X @tab X
102 @item Matroska @tab X @tab X
103 @item Monkey's Audio @tab @tab X
104 @item NUT @tab X @tab X
105 @tab NUT Open Container Format
106 @item Nullsoft Video @tab @tab X
107 @item OMA @tab @tab X
108 @tab Audio format used in Sony Sonic Stage and Sony Vegas.
109 @item PVA @tab @tab X
110 @tab Used by TechnoTrend DVB PCI boards.
111 @item PlayStation STR @tab @tab X
112 @item QuickTime @tab X @tab X
113 @item RL2 @tab @tab X
114 @tab Audio and video format used in some games by Entertainment Software Partners.
115 @item RealMedia @tab X @tab X
116 @item SEQ @tab @tab X
117 @tab Tiertex .seq files used in the DOS CD-ROM version of the game Flashback.
118 @item SIFF @tab @tab X
119 @tab Audio and video format used in some games by Beam Software.
120 @item SUN AU format @tab X @tab X
121 @item Sega FILM/CPK @tab @tab X
122 @tab Used in many Sega Saturn console games.
123 @item Sierra Online @tab @tab X
124 @tab .sol files used in Sierra Online games.
125 @item Sierra VMD @tab @tab X
126 @tab Used in Sierra CD-ROM games.
127 @item Smacker @tab @tab X
128 @tab Multimedia format used by many games.
129 @item THP @tab @tab X
130 @tab Used on the Nintendo GameCube.
131 @item WAV @tab X @tab X
132 @item WC3 Movie @tab @tab X
133 @tab Multimedia format used in Origin's Wing Commander III computer game.
134 @item Westwood Studios VQA/AUD @tab @tab X
135 @tab Multimedia formats used in Westwood Studios games.
136 @item id Cinematic @tab @tab X
137 @tab Used in Quake II.
138 @item id RoQ @tab X @tab X
139 @tab Used in Quake III, Jedi Knight 2, other computer games.
140 @item raw AC-3 @tab X @tab X
141 @item raw CRI ADX audio @tab X @tab X
142 @item raw MJPEG @tab X @tab X
143 @item raw MPEG video @tab X @tab X
144 @item raw MPEG-4 video @tab X @tab X
145 @item raw PCM 8/16 bits, mu-law/A-law @tab X @tab X
146 @item raw Shorten audio @tab @tab X
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 animated GIF @tab X @tab X @tab Only uncompressed GIFs are generated.
159 @item JPEG @tab X @tab X @tab Progressive JPEG is not supported.
160 @item PAM @tab X @tab X @tab PAM is a PNM extension with alpha support.
161 @item PCX @tab @tab X @tab PC Paintbrush
162 @item PGM, PPM @tab X @tab X
163 @item PGMYUV @tab X @tab X @tab PGM with U and V components in YUV 4:2:0
164 @item PNG @tab X @tab X @tab 2/4 bpp not supported yet
165 @item PTX @tab @tab X @tab V.Flash PTX format
166 @item RAS @tab @tab X @tab Sun Rasterfile
167 @item SGI @tab X @tab X @tab SGI RGB image format
168 @item TIFF @tab X @tab X @tab YUV, JPEG and some extension is not supported yet.
169 @item Targa @tab @tab X @tab Targa (.TGA) image format
170 @item .Y.U.V @tab X @tab X @tab one raw file per component
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 MPEG-1 video @tab X @tab X
180 @item MPEG-2 video @tab X @tab X
181 @item MPEG-4 @tab X @tab X
182 @item MSMPEG4 V1 @tab X @tab X
183 @item MSMPEG4 V2 @tab X @tab X
184 @item MSMPEG4 V3 @tab X @tab X
185 @item WMV7 @tab X @tab X
186 @item WMV8 @tab X @tab X
187 @item WMV9 @tab @tab X @tab not completely working
188 @item VC-1 @tab @tab X
189 @item H.261 @tab X @tab X
190 @item H.263(+) @tab X @tab X @tab also known as RealVideo 1.0
191 @item H.264 @tab @tab X
192 @item RealVideo 1.0 @tab X @tab X
193 @item RealVideo 2.0 @tab X @tab X
194 @item MJPEG @tab X @tab X
195 @item lossless MJPEG @tab X @tab X
196 @item JPEG-LS @tab X @tab X @tab fourcc: MJLS, lossless and near-lossless is supported.
197 @item Apple MJPEG-B @tab @tab X
198 @item Sunplus MJPEG @tab @tab X @tab fourcc: SP5X
199 @item DV @tab X @tab X
200 @item HuffYUV @tab X @tab X
201 @item FFmpeg Video 1 @tab X @tab X @tab experimental lossless codec (fourcc: FFV1)
202 @item Snow @tab X @tab X @tab experimental wavelet codec (fourcc: SNOW)
203 @item Asus v1 @tab X @tab X @tab fourcc: ASV1
204 @item Asus v2 @tab X @tab X @tab fourcc: ASV2
205 @item Creative YUV @tab @tab X @tab fourcc: CYUV
206 @item Sorenson Video 1 @tab X @tab X @tab fourcc: SVQ1
207 @item Sorenson Video 3 @tab @tab X @tab fourcc: SVQ3
208 @item On2 VP3 @tab @tab X @tab still experimental
209 @item On2 VP5 @tab @tab X @tab fourcc: VP50
210 @item On2 VP6 @tab @tab X @tab fourcc: VP60,VP61,VP62
211 @item Theora @tab X @tab X @tab still experimental
212 @item Intel Indeo 3 @tab @tab X
213 @item FLV @tab X @tab X @tab Sorenson H.263 used in Flash
214 @item Flash Screen Video @tab X @tab X @tab fourcc: FSV1
215 @item ATI VCR1 @tab @tab X @tab fourcc: VCR1
216 @item ATI VCR2 @tab @tab X @tab fourcc: VCR2
217 @item Cirrus Logic AccuPak @tab @tab X @tab fourcc: CLJR
218 @item 4X Video @tab @tab X @tab Used in certain computer games.
219 @item Sony PlayStation MDEC @tab @tab X
220 @item id RoQ @tab X @tab X @tab Used in Quake III, Jedi Knight 2, other computer games.
221 @item Xan/WC3 @tab @tab X @tab Used in Wing Commander III .MVE files.
222 @item Interplay Video @tab @tab X @tab Used in Interplay .MVE files.
223 @item Apple Animation @tab X @tab X @tab fourcc: 'rle '
224 @item Apple Graphics @tab @tab X @tab fourcc: 'smc '
225 @item Apple Video @tab @tab X @tab fourcc: rpza
226 @item Apple QuickDraw @tab @tab X @tab fourcc: qdrw
227 @item Cinepak @tab @tab X
228 @item Microsoft RLE @tab @tab X
229 @item Microsoft Video-1 @tab @tab X
230 @item Westwood VQA @tab @tab X
231 @item id Cinematic Video @tab @tab X @tab Used in Quake II.
232 @item planar RGB @tab @tab X @tab fourcc: 8BPS
233 @item FLIC video @tab @tab X
234 @item Duck TrueMotion v1 @tab @tab X @tab fourcc: DUCK
235 @item Duck TrueMotion v2 @tab @tab X @tab fourcc: TM20
236 @item VMD Video @tab @tab X @tab Used in Sierra VMD files.
237 @item MSZH @tab @tab X @tab Part of LCL
238 @item ZLIB @tab X @tab X @tab Part of LCL, encoder experimental
239 @item TechSmith Camtasia @tab @tab X @tab fourcc: TSCC
240 @item IBM Ultimotion @tab @tab X @tab fourcc: ULTI
241 @item Miro VideoXL @tab @tab X @tab fourcc: VIXL
242 @item QPEG @tab @tab X @tab fourccs: QPEG, Q1.0, Q1.1
243 @item LOCO @tab @tab X @tab
244 @item Winnov WNV1 @tab @tab X @tab
245 @item Autodesk RLE @tab @tab X @tab fourcc: AASC
246 @item Fraps FPS1 @tab @tab X @tab
247 @item CamStudio @tab @tab X @tab fourcc: CSCD
248 @item American Laser Games Video @tab @tab X @tab Used in games like Mad Dog McCree.
249 @item ZMBV @tab X @tab X @tab Encoder works only in PAL8.
250 @item AVS Video @tab @tab X @tab Video encoding used by the Creature Shock game.
251 @item Smacker Video @tab @tab X @tab Video encoding used in Smacker.
252 @item RTjpeg @tab @tab X @tab Video encoding used in NuppelVideo files.
253 @item KMVC @tab @tab X @tab Codec used in Worms games.
254 @item VMware Video @tab @tab X @tab Codec used in videos captured by VMware.
255 @item Cin Video @tab @tab X @tab Codec used in Delphine Software games.
256 @item Tiertex Seq Video @tab @tab X @tab Codec used in DOS CD-ROM FlashBack game.
257 @item DXA Video @tab @tab X @tab Codec originally used in Feeble Files game.
258 @item AVID DNxHD @tab X @tab X @tab aka SMPTE VC3
259 @item C93 Video @tab @tab X @tab Codec used in Cyberia game.
260 @item THP @tab @tab X @tab Used on the Nintendo GameCube.
261 @item Bethsoft VID @tab @tab X @tab Used in some games from Bethesda Softworks.
262 @item Renderware TXD @tab @tab X @tab Texture dictionaries used by the Renderware Engine.
263 @item AMV @tab @tab X @tab Used in Chinese MP3 players.
264 @item Mimic @tab @tab X @tab Used in MSN Messenger Webcam streams.
265 @item Electronic Arts CMV @tab @tab X @tab Used in NHL 95 game.
268 @code{X} means that encoding (resp. decoding) is supported.
270 @section Audio Codecs
272 @multitable @columnfractions .4 .1 .1 .1 .7
273 @item Supported Codec @tab Encoding @tab Decoding @tab Comments
274 @item MPEG audio layer 2 @tab IX @tab IX
275 @item MPEG audio layer 1/3 @tab X @tab IX
276 @tab MP3 encoding is supported through the external library LAME.
277 @item AC-3 @tab IX @tab IX
278 @tab liba52 can be used alternatively for decoding.
279 @item Vorbis @tab X @tab X
280 @item WMA V1/V2 @tab X @tab X
281 @item AAC @tab X @tab X
282 @tab Supported through the external library libfaac/libfaad.
283 @item Microsoft ADPCM @tab X @tab X
284 @item AMV IMA ADPCM @tab @tab X
285 @tab Used in AMV files
286 @item MS IMA ADPCM @tab X @tab X
287 @item QT IMA ADPCM @tab X @tab X
288 @item 4X IMA ADPCM @tab @tab X
289 @item G.726 ADPCM @tab X @tab X
290 @item Duck DK3 IMA ADPCM @tab @tab X
291 @tab Used in some Sega Saturn console games.
292 @item Duck DK4 IMA ADPCM @tab @tab X
293 @tab Used in some Sega Saturn console games.
294 @item Westwood Studios IMA ADPCM @tab @tab X
295 @tab Used in Westwood Studios games like Command and Conquer.
296 @item SMJPEG IMA ADPCM @tab @tab X
297 @tab Used in certain Loki game ports.
298 @item CD-ROM XA ADPCM @tab @tab X
299 @item CRI ADX ADPCM @tab X @tab X
300 @tab Used in Sega Dreamcast games.
301 @item Electronic Arts ADPCM @tab @tab X
302 @tab Used in various EA titles.
303 @item MAXIS EA ADPCM @tab @tab X
304 @tab Used in Sim City 3000.
305 @item Creative ADPCM @tab @tab X
306 @tab 16 -> 4, 8 -> 4, 8 -> 3, 8 -> 2
307 @item THP ADPCM @tab @tab X
308 @tab Used on the Nintendo GameCube.
309 @item RA144 @tab @tab X
310 @tab Real 14400 bit/s codec
311 @item RA288 @tab @tab X
312 @tab Real 28800 bit/s codec
313 @item RADnet @tab X @tab IX
314 @tab real low bitrate AC-3 codec
315 @item AMR-NB @tab X @tab X
316 @tab Supported through an external library.
317 @item AMR-WB @tab X @tab X
318 @tab Supported through an external library.
319 @item DV audio @tab @tab X
320 @item id RoQ DPCM @tab X @tab X
321 @tab Used in Quake III, Jedi Knight 2, other computer games.
322 @item Interplay MVE DPCM @tab @tab X
323 @tab Used in various Interplay computer games.
324 @item Xan DPCM @tab @tab X
325 @tab Used in Origin's Wing Commander IV AVI files.
326 @item Sierra Online DPCM @tab @tab X
327 @tab Used in Sierra Online game audio files.
328 @item Apple MACE 3 @tab @tab X
329 @item Apple MACE 6 @tab @tab X
330 @item FLAC lossless audio @tab X @tab X
331 @item Shorten lossless audio @tab @tab X
332 @item Apple lossless audio @tab @tab X
333 @tab QuickTime fourcc 'alac'
334 @item FFmpeg Sonic @tab X @tab X
335 @tab experimental lossy/lossless codec
336 @item Qdesign QDM2 @tab @tab X
337 @tab There are still some distortions.
338 @item Real COOK @tab @tab X
339 @tab All versions except 5.1 are supported.
340 @item DSP Group TrueSpeech @tab @tab X
341 @item True Audio (TTA) @tab @tab X
342 @item Smacker Audio @tab @tab X
343 @item WavPack Audio @tab @tab X
344 @item Cin Audio @tab @tab X
345 @tab Codec used in Delphine Software games.
346 @item Intel Music Coder @tab @tab X
347 @item Musepack @tab @tab X
348 @tab SV7 and SV8 are supported.
349 @item DTS Coherent Audio @tab @tab X
350 @item ATRAC 3 @tab @tab X
351 @item Monkey's Audio @tab @tab X @tab Only versions 3.97-3.99 are supported.
352 @item Nellymoser ASAO @tab @tab X
353 @item 8SVX Audio @tab @tab X
354 @item MLP/TrueHD @tab @tab X @tab Used in DVD-Audio and Blu-Ray discs.
357 @code{X} means that encoding (resp. decoding) is supported.
359 @code{I} means that an integer-only version is available, too (ensures high
360 performance on systems without hardware floating point support).
362 @chapter Platform Specific information
366 BSD make will not build FFmpeg, you need to install and use GNU Make
371 To get help and instructions for building FFmpeg under Windows, check out
372 the FFmpeg Windows Help Forum at
373 @url{http://arrozcru.no-ip.org/ffmpeg/}.
375 @subsection Native Windows compilation
377 FFmpeg can be built to run natively on Windows using the MinGW tools. Install
378 the current versions of MSYS and MinGW from @url{http://www.mingw.org/}. Also
379 install the coreutils package, and update to the latest MSYS make (note: not
380 mingw32-make). You can find detailed installation
381 instructions in the download section and the FAQ.
383 Within the MSYS shell, configure and make with:
386 ./configure --enable-memalign-hack
391 This will install @file{ffmpeg.exe} along with many other development files
392 to @file{/usr/local}. You may specify another install path using the
393 @code{--prefix} option in @file{configure}.
399 @item Use at least bash 3.1. Older versions are known to fail on the
402 @item In order to compile vhooks, you must have a POSIX-compliant libdl in
403 your MinGW system. Get dlfcn-win32 from
404 @url{http://code.google.com/p/dlfcn-win32}.
406 @item In order to compile FFplay, you must have the MinGW development library
407 of SDL. Get it from @url{http://www.libsdl.org}.
408 Edit the @file{bin/sdl-config} script so that it points to the correct prefix
409 where SDL was installed. Verify that @file{sdl-config} can be launched from
410 the MSYS command line.
412 @item By using @code{./configure --enable-shared} when configuring FFmpeg,
413 you can build libavutil, libavcodec and libavformat as DLLs.
417 @subsection Microsoft Visual C++ compatibility
419 As stated in the FAQ, FFmpeg will not compile under MSVC++. However, if you
420 want to use the libav* libraries in your own applications, you can still
421 compile those applications using MSVC++. But the libav* libraries you link
422 to @emph{must} be built with MinGW. However, you will not be able to debug
423 inside the libav* libraries, since MSVC++ does not recognize the debug
424 symbols generated by GCC.
425 We strongly recommend you to move over from MSVC++ to MinGW tools.
427 This description of how to use the FFmpeg libraries with MSVC++ is based on
428 Microsoft Visual C++ 2005 Express Edition. If you have a different version,
429 you might have to modify the procedures slightly.
431 @subsubsection Using static libraries
433 Assuming you have just built and installed FFmpeg in @file{/usr/local}.
437 @item Create a new console application ("File / New / Project") and then
438 select "Win32 Console Application". On the appropriate page of the
439 Application Wizard, uncheck the "Precompiled headers" option.
441 @item Write the source code for your application, or, for testing, just
442 copy the code from an existing sample application into the source file
443 that MSVC++ has already created for you. For example, you can copy
444 @file{output_example.c} from the FFmpeg distribution.
446 @item Open the "Project / Properties" dialog box. In the "Configuration"
447 combo box, select "All Configurations" so that the changes you make will
448 affect both debug and release builds. In the tree view on the left hand
449 side, select "C/C++ / General", then edit the "Additional Include
450 Directories" setting to contain the path where the FFmpeg includes were
451 installed (i.e. @file{c:\msys\1.0\local\include}).
452 Do not add MinGW's include directory here, or the include files will
453 conflict with MSVC's.
455 @item Still in the "Project / Properties" dialog box, select
456 "Linker / General" from the tree view and edit the
457 "Additional Library Directories" setting to contain the @file{lib}
458 directory where FFmpeg was installed (i.e. @file{c:\msys\1.0\local\lib}),
459 the directory where MinGW libs are installed (i.e. @file{c:\mingw\lib}),
460 and the directory where MinGW's GCC libs are installed
461 (i.e. @file{C:\mingw\lib\gcc\mingw32\4.2.1-sjlj}). Then select
462 "Linker / Input" from the tree view, and add the files @file{libavformat.a},
463 @file{libavcodec.a}, @file{libavutil.a}, @file{libmingwex.a},
464 @file{libgcc.a}, and any other libraries you used (i.e. @file{libz.a})
465 to the end of "Additional Dependencies".
467 @item Now, select "C/C++ / Code Generation" from the tree view. Select
468 "Debug" in the "Configuration" combo box. Make sure that "Runtime
469 Library" is set to "Multi-threaded Debug DLL". Then, select "Release" in
470 the "Configuration" combo box and make sure that "Runtime Library" is
471 set to "Multi-threaded DLL".
473 @item Click "OK" to close the "Project / Properties" dialog box.
475 @item MSVC++ lacks some C99 header files that are fundamental for FFmpeg.
476 Get msinttypes from @url{http://code.google.com/p/msinttypes/downloads/list}
477 and install it in MSVC++'s include directory
478 (i.e. @file{C:\Program Files\Microsoft Visual Studio 8\VC\include}).
480 @item MSVC++ also does not understand the @code{inline} keyword used by
481 FFmpeg, so you must add this line before @code{#include}ing libav*:
483 #define inline _inline
486 @item Build your application, everything should work.
490 @subsubsection Using shared libraries
492 This is how to create DLL and LIB files that are compatible with MSVC++:
496 @item Add a call to @file{vcvars32.bat} (which sets up the environment
497 variables for the Visual C++ tools) as the first line of @file{msys.bat}.
498 The standard location for @file{vcvars32.bat} is
499 @file{C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat},
500 and the standard location for @file{msys.bat} is @file{C:\msys\1.0\msys.bat}.
501 If this corresponds to your setup, add the following line as the first line
505 call "C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat"
508 Alternatively, you may start the @file{Visual Studio 2005 Command Prompt},
509 and run @file{c:\msys\1.0\msys.bat} from there.
511 @item Within the MSYS shell, run @code{lib.exe}. If you get a help message
512 from @file{Microsoft (R) Library Manager}, this means your environment
513 variables are set up correctly, the @file{Microsoft (R) Library Manager}
514 is on the path and will be used by FFmpeg to create
515 MSVC++-compatible import libraries.
517 @item Build FFmpeg with
520 ./configure --enable-shared --enable-memalign-hack
525 Your install path (@file{/usr/local/} by default) should now have the
526 necessary DLL and LIB files under the @file{bin} directory.
530 To use those files with MSVC++, do the same as you would do with
531 the static libraries, as described above. But in Step 4,
532 you should only need to add the directory where the LIB files are installed
533 (i.e. @file{c:\msys\usr\local\bin}). This is not a typo, the LIB files are
534 installed in the @file{bin} directory. And instead of adding @file{libxx.a}
535 files, you should add @file{avcodec.lib}, @file{avformat.lib}, and
536 @file{avutil.lib}. There should be no need for @file{libmingwex.a},
537 @file{libgcc.a}, and @file{wsock32.lib}, nor any other external library
538 statically linked into the DLLs. The @file{bin} directory contains a bunch
539 of DLL files, but the ones that are actually used to run your application
540 are the ones with a major version number in their filenames
541 (i.e. @file{avcodec-51.dll}).
543 @subsection Cross compilation for Windows with Linux
545 You must use the MinGW cross compilation tools available at
546 @url{http://www.mingw.org/}.
548 Then configure FFmpeg with the following options:
550 ./configure --target-os=mingw32 --cross-prefix=i386-mingw32msvc-
552 (you can change the cross-prefix according to the prefix chosen for the
555 Then you can easily test FFmpeg with Wine
556 (@url{http://www.winehq.com/}).
558 @subsection Compilation under Cygwin
560 The main issue with Cygwin is that newlib, its C library, does not
561 contain llrint(). However, it is possible to leverage the
562 implementation in MinGW.
564 Just install your Cygwin with all the "Base" packages, plus the
565 following "Devel" ones:
567 binutils, gcc-core, make, subversion, mingw-runtime
570 Do not install binutils-20060709-1 (they are buggy on shared builds);
571 use binutils-20050610-1 instead.
573 Then create a small library that just contains llrint():
576 ar x /usr/lib/mingw/libmingwex.a llrint.o
577 ar cq /usr/local/lib/libllrint.a llrint.o
583 ./configure --enable-static --disable-shared --extra-ldflags='-L /usr/local/lib' --extra-libs='-l llrint'
586 to make a static build or
589 ./configure --enable-shared --disable-static --extra-ldflags='-L /usr/local/lib' --extra-libs='-l llrint'
592 to build shared libraries.
594 If you want to build FFmpeg with additional libraries, download Cygwin
595 "Devel" packages for Ogg and Vorbis from any Cygwin packages repository
596 and/or SDL, xvid, faac, faad2 packages from Cygwin Ports,
597 (@url{http://cygwinports.dotsrc.org/}).
599 @subsection Crosscompilation for Windows under Cygwin
601 With Cygwin you can create Windows binaries that do not need the cygwin1.dll.
603 Just install your Cygwin as explained before, plus these additional
606 gcc-mingw-core, mingw-runtime, mingw-zlib
609 and add some special flags to your configure invocation.
611 For a static build run
613 ./configure --target-os=mingw32 --enable-memalign-hack --enable-static --disable-shared --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
616 and for a build with shared libraries
618 ./configure --target-os=mingw32 --enable-memalign-hack --enable-shared --disable-static --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
623 BeOS support is broken in mysterious ways.
627 For information about compiling FFmpeg on OS/2 see
628 @url{http://www.edm2.com/index.php/FFmpeg}.
630 @chapter Developers Guide
634 @item libavcodec is the library containing the codecs (both encoding and
635 decoding). Look at @file{libavcodec/apiexample.c} to see how to use it.
637 @item libavformat is the library containing the file format handling (mux and
638 demux code for several formats). Look at @file{ffplay.c} to use it in a
639 player. See @file{output_example.c} to use it to generate audio or video
644 @section Integrating libavcodec or libavformat in your program
646 You can integrate all the source code of the libraries to link them
647 statically to avoid any version problem. All you need is to provide a
648 'config.mak' and a 'config.h' in the parent directory. See the defines
649 generated by ./configure to understand what is needed.
651 You can use libavcodec or libavformat in your commercial program, but
652 @emph{any patch you make must be published}. The best way to proceed is
653 to send your patches to the FFmpeg mailing list.
656 @section Coding Rules
658 FFmpeg is programmed in the ISO C90 language with a few additional
659 features from ISO C99, namely:
662 the @samp{inline} keyword;
666 designated struct initializers (@samp{struct s x = @{ .i = 17 @};})
668 compound literals (@samp{x = (struct s) @{ 17, 23 @};})
671 These features are supported by all compilers we care about, so we will not
672 accept patches to remove their use unless they absolutely do not impair
673 clarity and performance.
675 All code must compile with GCC 2.95 and GCC 3.3. Currently, FFmpeg also
676 compiles with several other compilers, such as the Compaq ccc compiler
677 or Sun Studio 9, and we would like to keep it that way unless it would
678 be exceedingly involved. To ensure compatibility, please do not use any
679 additional C99 features or GCC extensions. Especially watch out for:
682 mixing statements and declarations;
684 @samp{long long} (use @samp{int64_t} instead);
686 @samp{__attribute__} not protected by @samp{#ifdef __GNUC__} or similar;
688 GCC statement expressions (@samp{(x = (@{ int y = 4; y; @})}).
692 The presentation is the one specified by 'indent -i4 -kr -nut'.
693 The TAB character is forbidden outside of Makefiles as is any
694 form of trailing whitespace. Commits containing either will be
695 rejected by the Subversion repository.
697 The main priority in FFmpeg is simplicity and small code size in order to
698 minimize the bug count.
700 Comments: Use the JavaDoc/Doxygen
701 format (see examples below) so that code documentation
702 can be generated automatically. All nontrivial functions should have a comment
703 above them explaining what the function does, even if it is just one sentence.
704 All structures and their member variables should be documented, too.
717 typedef struct Foobar@{
718 int var1; /**< var1 description */
719 int var2; ///< var2 description
720 /** var3 description */
728 * @@param my_parameter description of my_parameter
729 * @@return return value description
731 int myfunc(int my_parameter)
735 fprintf and printf are forbidden in libavformat and libavcodec,
736 please use av_log() instead.
738 Casts should be used only when necessary. Unneeded parentheses
739 should also be avoided if they don't make the code easier to understand.
741 @section Development Policy
745 Contributions should be licensed under the LGPL 2.1, including an
746 "or any later version" clause, or the MIT license. GPL 2 including
747 an "or any later version" clause is also acceptable, but LGPL is
750 You must not commit code which breaks FFmpeg! (Meaning unfinished but
751 enabled code which breaks compilation or compiles but does not work or
752 breaks the regression tests)
753 You can commit unfinished stuff (for testing etc), but it must be disabled
754 (#ifdef etc) by default so it does not interfere with other developers'
757 You do not have to over-test things. If it works for you, and you think it
758 should work for others, then commit. If your code has problems
759 (portability, triggers compiler bugs, unusual environment etc) they will be
760 reported and eventually fixed.
762 Do not commit unrelated changes together, split them into self-contained
763 pieces. Also do not forget that if part B depends on part A, but A does not
764 depend on B, then A can and should be committed first and separate from B.
765 Keeping changes well split into self-contained parts makes reviewing and
766 understanding them on the commit log mailing list easier. This also helps
767 in case of debugging later on.
768 Also if you have doubts about splitting or not splitting, do not hesitate to
769 ask/discuss it on the developer mailing list.
771 Do not change behavior of the program (renaming options etc) without
772 first discussing it on the ffmpeg-devel mailing list. Do not remove
773 functionality from the code. Just improve!
775 Note: Redundant code can be removed.
777 Do not commit changes to the build system (Makefiles, configure script)
778 which change behavior, defaults etc, without asking first. The same
779 applies to compiler warning fixes, trivial looking fixes and to code
780 maintained by other developers. We usually have a reason for doing things
781 the way we do. Send your changes as patches to the ffmpeg-devel mailing
782 list, and if the code maintainers say OK, you may commit. This does not
783 apply to files you wrote and/or maintain.
785 We refuse source indentation and other cosmetic changes if they are mixed
786 with functional changes, such commits will be rejected and removed. Every
787 developer has his own indentation style, you should not change it. Of course
788 if you (re)write something, you can use your own style, even though we would
789 prefer if the indentation throughout FFmpeg was consistent (Many projects
790 force a given indentation style - we do not.). If you really need to make
791 indentation changes (try to avoid this), separate them strictly from real
794 NOTE: If you had to put if()@{ .. @} over a large (> 5 lines) chunk of code,
795 then either do NOT change the indentation of the inner part within (do not
796 move it to the right)! or do so in a separate commit
798 Always fill out the commit log message. Describe in a few lines what you
799 changed and why. You can refer to mailing list postings if you fix a
800 particular bug. Comments such as "fixed!" or "Changed it." are unacceptable.
802 If you apply a patch by someone else, include the name and email address in
803 the log message. Since the ffmpeg-cvslog mailing list is publicly
804 archived you should add some SPAM protection to the email address. Send an
805 answer to ffmpeg-devel (or wherever you got the patch from) saying that
806 you applied the patch.
808 When applying patches that have been discussed (at length) on the mailing
809 list, reference the thread in the log message.
811 Do NOT commit to code actively maintained by others without permission.
812 Send a patch to ffmpeg-devel instead. If no one answers within a reasonable
813 timeframe (12h for build failures and security fixes, 3 days small changes,
814 1 week for big patches) then commit your patch if you think it is OK.
815 Also note, the maintainer can simply ask for more time to review!
817 Subscribe to the ffmpeg-cvslog mailing list. The diffs of all commits
818 are sent there and reviewed by all the other developers. Bugs and possible
819 improvements or general questions regarding commits are discussed there. We
820 expect you to react if problems with your code are uncovered.
822 Update the documentation if you change behavior or add features. If you are
823 unsure how best to do this, send a patch to ffmpeg-devel, the documentation
824 maintainer(s) will review and commit your stuff.
826 Try to keep important discussions and requests (also) on the public
827 developer mailing list, so that all developers can benefit from them.
829 Never write to unallocated memory, never write over the end of arrays,
830 always check values read from some untrusted source before using them
831 as array index or other risky things.
833 Remember to check if you need to bump versions for the specific libav
834 parts (libavutil, libavcodec, libavformat) you are changing. You need
835 to change the version integer and the version string.
836 Incrementing the first component means no backward compatibility to
837 previous versions (e.g. removal of a function from the public API).
838 Incrementing the second component means backward compatible change
839 (e.g. addition of a function to the public API).
840 Incrementing the third component means a noteworthy binary compatible
841 change (e.g. encoder bug fix that matters for the decoder).
843 If you add a new codec, remember to update the changelog, add it to
844 the supported codecs table in the documentation and bump the second
845 component of the @file{libavcodec} version number appropriately. If
846 it has a fourcc, add it to @file{libavformat/riff.c}, even if it
849 Compiler warnings indicate potential bugs or code with bad style. If a type of
850 warning always points to correct and clean code, that warning should
851 be disabled, not the code changed.
852 Thus the remaining warnings can either be bugs or correct code.
853 If it is a bug, the bug has to be fixed. If it is not, the code should
854 be changed to not generate a warning unless that causes a slowdown
855 or obfuscates the code.
857 If you add a new file, give it a proper license header. Do not copy and
858 paste it from a random place, use an existing file as template.
861 We think our rules are not too hard. If you have comments, contact us.
863 Note, these rules are mostly borrowed from the MPlayer project.
865 @section Submitting patches
867 First, (@pxref{Coding Rules}) above if you did not yet.
869 When you submit your patch, try to send a unified diff (diff '-up'
870 option). We cannot read other diffs :-)
872 Also please do not submit a patch which contains several unrelated changes.
873 Split it into separate, self-contained pieces. This does not mean splitting
874 file by file. Instead, make the patch as small as possible while still
875 keeping it as a logical unit that contains an individual change, even
876 if it spans multiple files. This makes reviewing your patches much easier
877 for us and greatly increases your chances of getting your patch applied.
879 Run the regression tests before submitting a patch so that you can
880 verify that there are no big problems.
882 Patches should be posted as base64 encoded attachments (or any other
883 encoding which ensures that the patch will not be trashed during
884 transmission) to the ffmpeg-devel mailing list, see
885 @url{http://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel}
887 It also helps quite a bit if you tell us what the patch does (for example
888 'replaces lrint by lrintf'), and why (for example '*BSD isn't C99 compliant
891 Also please if you send several patches, send each patch as a separate mail,
892 do not attach several unrelated patches to the same mail.
894 @section patch submission checklist
898 Do the regression tests pass with the patch applied?
900 Is the patch a unified diff?
902 Is the patch against latest FFmpeg SVN?
904 Are you subscribed to ffmpeg-dev?
905 (the list is subscribers only due to spam)
907 Have you checked that the changes are minimal, so that the same cannot be
908 achieved with a smaller patch and/or simpler final code?
910 If the change is to speed critical code, did you benchmark it?
912 If you did any benchmarks, did you provide them in the mail?
914 Have you checked that the patch does not introduce buffer overflows or
915 other security issues?
917 If you add a new demuxer or decoder, have you checked that it does not
918 crash with damaged input (see tools/trasher)?
920 Is the patch created from the root of the source tree, so it can be
921 applied with @code{patch -p0}?
923 Does the patch not mix functional and cosmetic changes?
925 Did you add tabs or trailing whitespace to the code? Both are forbidden.
927 Is the patch attached to the email you send?
929 Is the mime type of the patch correct? It should be text/x-diff or
930 text/x-patch or at least text/plain and not application/octet-stream.
932 If the patch fixes a bug, did you provide a verbose analysis of the bug?
934 If the patch fixes a bug, did you provide enough information, including
935 a sample, so the bug can be reproduced and the fix can be verified?
936 Note please do not attach samples >100k to mails but rather provide a
937 URL, you can upload to ftp://upload.mplayerhq.hu
939 Did you provide a verbose summary about what the patch does change?
941 Did you provide a verbose explanation why it changes things like it does?
943 Did you provide a verbose summary of the user visible advantages and
944 disadvantages if the patch is applied?
946 Did you provide an example so we can verify the new feature added by the
949 If you added a new file, did you insert a license header? It should be
950 taken from FFmpeg, not randomly copied and pasted from somewhere else.
952 You should maintain alphabetical order in alphabetically ordered lists as
953 long as doing so does not break API/ABI compatibility.
955 Lines with similar content should be aligned vertically when doing so
956 improves readability.
958 Did you provide a suggestion for a clear commit log message?
960 Did you test your decoder or demuxer against damaged data? If no, see
961 tools/trasher and the noise bitstream filter. Your decoder or demuxer
962 should not crash or end in a (near) infinite loop when fed damaged data.
965 @section Patch review process
967 All patches posted to ffmpeg-devel will be reviewed, unless they contain a
968 clear note that the patch is not for SVN.
969 Reviews and comments will be posted as replies to the patch on the
970 mailing list. The patch submitter then has to take care of every comment,
971 that can be by resubmitting a changed patch or by discussion. Resubmitted
972 patches will themselves be reviewed like any other patch. If at some point
973 a patch passes review with no comments then it is approved, that can for
974 simple and small patches happen immediately while large patches will generally
975 have to be changed and reviewed many times before they are approved.
976 After a patch is approved it will be committed to the repository.
978 We will review all submitted patches, but sometimes we are quite busy so
979 especially for large patches this can take several weeks.
981 When resubmitting patches, please do not make any significant changes
982 not related to the comments received during review. Such patches will
983 be rejected. Instead, submit significant changes or new features as
986 @section Regression tests
988 Before submitting a patch (or committing to the repository), you should at least
989 test that you did not break anything.
991 The regression tests build a synthetic video stream and a synthetic
992 audio stream. These are then encoded and decoded with all codecs or
993 formats. The CRC (or MD5) of each generated file is recorded in a
994 result file. A 'diff' is launched to compare the reference results and
997 The regression tests then go on to test the FFserver code with a
998 limited set of streams. It is important that this step runs correctly
1001 Run 'make test' to test all the codecs and formats.
1003 Run 'make fulltest' to test all the codecs, formats and FFserver.
1005 [Of course, some patches may change the results of the regression tests. In
1006 this case, the reference results of the regression tests shall be modified