Electronic Arts CMV latent dox entry
[libav.git] / doc / general.texi
1 \input texinfo @c -*- texinfo -*-
3 @settitle General Documentation
4 @titlepage
5 @sp 7
6 @center @titlefont{General Documentation}
7 @sp 3
8 @end titlepage
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}.
17 @section AMR
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.
37 @section File Formats
39 FFmpeg supports the following file formats through the @code{libavformat}
40 library:
42 @multitable @columnfractions .4 .1 .1 .4
43 @item Supported File Format @tab Encoding @tab Decoding @tab Comments
44 @item MPEG audio @tab X @tab X
45 @item MPEG-1 systems @tab X @tab X
46 @tab muxed audio and video
47 @item MPEG-2 PS @tab X @tab X
48 @tab also known as @code{VOB} file
49 @item MPEG-2 TS @tab @tab X
50 @tab also known as DVB Transport Stream
51 @item ASF@tab X @tab X
52 @item AVI@tab X @tab X
53 @item WAV@tab X @tab X
54 @item Macromedia Flash@tab X @tab X
55 @item AVM2 (Flash 9) @tab X @tab X
56 @tab Only embedded audio is decoded.
57 @item FLV @tab X @tab X
58 @tab Macromedia Flash video files
59 @item Real Audio and Video @tab X @tab X
60 @item Raw AC3 @tab X @tab X
61 @item Raw MJPEG @tab X @tab X
62 @item Raw MPEG video @tab X @tab X
63 @item Raw PCM8/16 bits, mulaw/Alaw@tab X @tab X
64 @item Raw CRI ADX audio @tab X @tab X
65 @item Raw Shorten audio @tab @tab X
66 @item SUN AU format @tab X @tab X
67 @item NUT @tab X @tab X @tab NUT Open Container Format
68 @item QuickTime @tab X @tab X
69 @item MPEG-4 @tab X @tab X
70 @tab MPEG-4 is a variant of QuickTime.
71 @item Raw MPEG4 video @tab X @tab X
72 @item DV @tab X @tab X
73 @item 4xm @tab @tab X
74 @tab 4X Technologies format, used in some games.
75 @item PlayStation STR @tab @tab X
76 @item id RoQ @tab X @tab X
77 @tab Used in Quake III, Jedi Knight 2, other computer games.
78 @item Interplay MVE @tab @tab X
79 @tab Format used in various Interplay computer games.
80 @item WC3 Movie @tab @tab X
81 @tab Multimedia format used in Origin's Wing Commander III computer game.
82 @item Sega FILM/CPK @tab @tab X
83 @tab Used in many Sega Saturn console games.
84 @item Westwood Studios VQA/AUD @tab @tab X
85 @tab Multimedia formats used in Westwood Studios games.
86 @item id Cinematic (.cin) @tab @tab X
87 @tab Used in Quake II.
88 @item FLIC format @tab @tab X
89 @tab .fli/.flc files
90 @item Sierra VMD @tab @tab X
91 @tab Used in Sierra CD-ROM games.
92 @item Sierra Online @tab @tab X
93 @tab .sol files used in Sierra Online games.
94 @item Matroska @tab X @tab X
95 @item Electronic Arts Multimedia @tab @tab X
96 @tab Used in various EA games; files have extensions like WVE and UV2.
97 @item MAXIS EA XA @tab @tab X
98 @tab Used in Sim City 3000; file extension .xa.
99 @item Nullsoft Video (NSV) format @tab @tab X
100 @item ADTS AAC audio @tab X @tab X
101 @item Creative VOC @tab X @tab X @tab Created for the Sound Blaster Pro.
102 @item American Laser Games MM @tab @tab X
103 @tab Multimedia format used in games like Mad Dog McCree
104 @item AVS @tab @tab X
105 @tab Multimedia format used by the Creature Shock game.
106 @item Smacker @tab @tab X
107 @tab Multimedia format used by many games.
108 @item GXF @tab X @tab X
109 @tab General eXchange Format SMPTE 360M, used by Thomson Grass Valley playout servers.
110 @item CIN @tab @tab X
111 @tab Multimedia format used by Delphine Software games.
112 @item MXF @tab @tab X
113 @tab Material eXchange Format SMPTE 377M, used by D-Cinema, broadcast industry.
114 @item SEQ @tab @tab X
115 @tab Tiertex .seq files used in the DOS CD-ROM version of the game Flashback.
116 @item DXA @tab @tab X
117 @tab This format is used in non-Windows version of Feeble Files game and
118 different game cutscenes repacked for use with ScummVM.
119 @item THP @tab @tab X
120 @tab Used on the Nintendo GameCube.
121 @item C93 @tab @tab X
122 @tab Used in the game Cyberia from Interplay.
123 @item Bethsoft VID @tab @tab X
124 @tab Used in some games from Bethesda Softworks.
125 @item CRYO APC @tab @tab X
126 @tab Audio format used in some games by CRYO Interactive Entertainment.
127 @item Monkey's Audio @tab @tab X
128 @item SIFF @tab @tab X
129 @tab Audio and video format used in some games by Beam Software
130 @item LMLM4 @tab @tab X
131 @tab Used by Linux Media Labs MPEG-4 PCI boards
132 @item PVA @tab @tab X
133 @tab Used by TechnoTrend DVB PCI boards
134 @item MSN TCP Webcam @tab @tab X
135 @tab Used by MSN Messenger Webcam streams.
136 @item RL2 @tab @tab X
137 @tab Audio and video format used in some games by Entertainment Software Partners
138 @item IFF @tab @tab X
139 @tab Interchange File Format
140 @item BFI @tab @tab X
141 @tab Brute Force & Ignorance, used in Flash Traffic: City of Angels
142 @item OMA @tab @tab X
143 @tab Audio format used in Sony Sonic Stage and Sony Vegas
144 @end multitable
146 @code{X} means that encoding (resp. decoding) is supported.
148 @section Image Formats
150 FFmpeg can read and write images for each frame of a video sequence. The
151 following image formats are supported:
153 @multitable @columnfractions .4 .1 .1 .4
154 @item Supported Image Format @tab Encoding @tab Decoding @tab Comments
155 @item PGM, PPM @tab X @tab X
156 @item PAM @tab X @tab X @tab PAM is a PNM extension with alpha support.
157 @item PGMYUV @tab X @tab X @tab PGM with U and V components in YUV 4:2:0
158 @item JPEG @tab X @tab X @tab Progressive JPEG is not supported.
159 @item .Y.U.V @tab X @tab X @tab one raw file per component
160 @item animated GIF @tab X @tab X @tab Only uncompressed GIFs are generated.
161 @item PNG @tab X @tab X @tab 2 bit and 4 bit/pixel not supported yet.
162 @item Targa @tab @tab X @tab Targa (.TGA) image format.
163 @item TIFF @tab X @tab X @tab YUV, JPEG and some extension is not supported yet.
164 @item SGI @tab X @tab X @tab SGI RGB image format
165 @item PTX @tab @tab X @tab V.Flash PTX format
166 @item RAS @tab @tab X @tab Sun Rasterfile
167 @item PCX @tab @tab X @tab PC Paintbrush
168 @end multitable
170 @code{X} means that encoding (resp. decoding) is supported.
172 @section Video Codecs
174 @multitable @columnfractions .4 .1 .1 .4
175 @item Supported Codec @tab Encoding @tab Decoding @tab Comments
176 @item MPEG-1 video @tab X @tab X
177 @item MPEG-2 video @tab X @tab X
178 @item MPEG-4 @tab X @tab X
179 @item MSMPEG4 V1 @tab X @tab X
180 @item MSMPEG4 V2 @tab X @tab X
181 @item MSMPEG4 V3 @tab X @tab X
182 @item WMV7 @tab X @tab X
183 @item WMV8 @tab X @tab X @tab not completely working
184 @item WMV9 @tab @tab X @tab not completely working
185 @item VC1 @tab @tab X
186 @item H.261 @tab X @tab X
187 @item H.263(+) @tab X @tab X @tab also known as RealVideo 1.0
188 @item H.264 @tab @tab X
189 @item RealVideo 1.0 @tab X @tab X
190 @item RealVideo 2.0 @tab X @tab X
191 @item MJPEG @tab X @tab X
192 @item lossless MJPEG @tab X @tab X
193 @item JPEG-LS @tab X @tab X @tab fourcc: MJLS, lossless and near-lossless is supported
194 @item Apple MJPEG-B @tab @tab X
195 @item Sunplus MJPEG @tab @tab X @tab fourcc: SP5X
196 @item DV @tab X @tab X
197 @item HuffYUV @tab X @tab X
198 @item FFmpeg Video 1 @tab X @tab X @tab experimental lossless codec (fourcc: FFV1)
199 @item FFmpeg Snow @tab X @tab X @tab experimental wavelet codec (fourcc: SNOW)
200 @item Asus v1 @tab X @tab X @tab fourcc: ASV1
201 @item Asus v2 @tab X @tab X @tab fourcc: ASV2
202 @item Creative YUV @tab @tab X @tab fourcc: CYUV
203 @item Sorenson Video 1 @tab X @tab X @tab fourcc: SVQ1
204 @item Sorenson Video 3 @tab @tab X @tab fourcc: SVQ3
205 @item On2 VP3 @tab @tab X @tab still experimental
206 @item On2 VP5 @tab @tab X @tab fourcc: VP50
207 @item On2 VP6 @tab @tab X @tab fourcc: VP60,VP61,VP62
208 @item Theora @tab X @tab X @tab still experimental
209 @item Intel Indeo 3 @tab @tab X
210 @item FLV @tab X @tab X @tab Sorenson H.263 used in Flash
211 @item Flash Screen Video @tab X @tab X @tab fourcc: FSV1
212 @item ATI VCR1 @tab @tab X @tab fourcc: VCR1
213 @item ATI VCR2 @tab @tab X @tab fourcc: VCR2
214 @item Cirrus Logic AccuPak @tab @tab X @tab fourcc: CLJR
215 @item 4X Video @tab @tab X @tab Used in certain computer games.
216 @item Sony PlayStation MDEC @tab @tab X
217 @item id RoQ @tab X @tab X @tab Used in Quake III, Jedi Knight 2, other computer games.
218 @item Xan/WC3 @tab @tab X @tab Used in Wing Commander III .MVE files.
219 @item Interplay Video @tab @tab X @tab Used in Interplay .MVE files.
220 @item Apple Animation @tab X @tab X @tab fourcc: 'rle '
221 @item Apple Graphics @tab @tab X @tab fourcc: 'smc '
222 @item Apple Video @tab @tab X @tab fourcc: rpza
223 @item Apple QuickDraw @tab @tab X @tab fourcc: qdrw
224 @item Cinepak @tab @tab X
225 @item Microsoft RLE @tab @tab X
226 @item Microsoft Video-1 @tab @tab X
227 @item Westwood VQA @tab @tab X
228 @item id Cinematic Video @tab @tab X @tab Used in Quake II.
229 @item Planar RGB @tab @tab X @tab fourcc: 8BPS
230 @item FLIC video @tab @tab X
231 @item Duck TrueMotion v1 @tab @tab X @tab fourcc: DUCK
232 @item Duck TrueMotion v2 @tab @tab X @tab fourcc: TM20
233 @item VMD Video @tab @tab X @tab Used in Sierra VMD files.
234 @item MSZH @tab @tab X @tab Part of LCL
235 @item ZLIB @tab X @tab X @tab Part of LCL, encoder experimental
236 @item TechSmith Camtasia @tab @tab X @tab fourcc: TSCC
237 @item IBM Ultimotion @tab @tab X @tab fourcc: ULTI
238 @item Miro VideoXL @tab @tab X @tab fourcc: VIXL
239 @item QPEG @tab @tab X @tab fourccs: QPEG, Q1.0, Q1.1
240 @item LOCO @tab @tab X @tab
241 @item Winnov WNV1 @tab @tab X @tab
242 @item Autodesk Animator Studio Codec @tab @tab X @tab fourcc: AASC
243 @item Fraps FPS1 @tab @tab X @tab
244 @item CamStudio @tab @tab X @tab fourcc: CSCD
245 @item American Laser Games Video @tab @tab X @tab Used in games like Mad Dog McCree
246 @item ZMBV @tab X @tab X @tab Encoder works only on PAL8
247 @item AVS Video @tab @tab X @tab Video encoding used by the Creature Shock game.
248 @item Smacker Video @tab @tab X @tab Video encoding used in Smacker.
249 @item RTjpeg @tab @tab X @tab Video encoding used in NuppelVideo files.
250 @item KMVC @tab @tab X @tab Codec used in Worms games.
251 @item VMware Video @tab @tab X @tab Codec used in videos captured by VMware.
252 @item Cin Video @tab @tab X @tab Codec used in Delphine Software games.
253 @item Tiertex Seq Video @tab @tab X @tab Codec used in DOS CD-ROM FlashBack game.
254 @item DXA Video @tab @tab X @tab Codec originally used in Feeble Files game.
255 @item AVID DNxHD @tab X @tab X @tab aka SMPTE VC3
256 @item C93 Video @tab @tab X @tab Codec used in Cyberia game.
257 @item THP @tab @tab X @tab Used on the Nintendo GameCube.
258 @item Bethsoft VID @tab @tab X @tab Used in some games from Bethesda Softworks.
259 @item Renderware TXD @tab @tab X @tab Texture dictionaries used by the Renderware Engine.
260 @item AMV @tab @tab X @tab Used in Chinese MP3 players.
261 @item Mimic @tab @tab X @tab Used in MSN Messenger Webcam streams.
262 @item Electronic Arts CMV @tab @tab X @tab Used in NHL 95 game.
263 @end multitable
265 @code{X} means that encoding (resp. decoding) is supported.
267 @section Audio Codecs
269 @multitable @columnfractions .4 .1 .1 .1 .7
270 @item Supported Codec @tab Encoding @tab Decoding @tab Comments
271 @item MPEG audio layer 2 @tab IX @tab IX
272 @item MPEG audio layer 1/3 @tab X @tab IX
273 @tab MP3 encoding is supported through the external library LAME.
274 @item AC3 @tab IX @tab IX
275 @tab liba52 is used internally for decoding.
276 @item Vorbis @tab X @tab X
277 @item WMA V1/V2 @tab X @tab X
278 @item AAC @tab X @tab X
279 @tab Supported through the external library libfaac/libfaad.
280 @item Microsoft ADPCM @tab X @tab X
281 @item AMV IMA ADPCM @tab @tab X
282 @tab Used in AMV files
283 @item MS IMA ADPCM @tab X @tab X
284 @item QT IMA ADPCM @tab X @tab X
285 @item 4X IMA ADPCM @tab @tab X
286 @item G.726 ADPCM @tab X @tab X
287 @item Duck DK3 IMA ADPCM @tab @tab X
288 @tab Used in some Sega Saturn console games.
289 @item Duck DK4 IMA ADPCM @tab @tab X
290 @tab Used in some Sega Saturn console games.
291 @item Westwood Studios IMA ADPCM @tab @tab X
292 @tab Used in Westwood Studios games like Command and Conquer.
293 @item SMJPEG IMA ADPCM @tab @tab X
294 @tab Used in certain Loki game ports.
295 @item CD-ROM XA ADPCM @tab @tab X
296 @item CRI ADX ADPCM @tab X @tab X
297 @tab Used in Sega Dreamcast games.
298 @item Electronic Arts ADPCM @tab @tab X
299 @tab Used in various EA titles.
300 @item MAXIS EA ADPCM @tab @tab X
301 @tab Used in Sim City 3000.
302 @item Creative ADPCM @tab @tab X
303 @tab 16 -> 4, 8 -> 4, 8 -> 3, 8 -> 2
304 @item THP ADPCM @tab @tab X
305 @tab Used on the Nintendo GameCube.
306 @item RA144 @tab @tab X
307 @tab Real 14400 bit/s codec
308 @item RA288 @tab @tab X
309 @tab Real 28800 bit/s codec
310 @item RADnet @tab X @tab IX
311 @tab Real low bitrate AC3 codec, liba52 is used for decoding.
312 @item AMR-NB @tab X @tab X
313 @tab Supported through an external library.
314 @item AMR-WB @tab X @tab X
315 @tab Supported through an external library.
316 @item DV audio @tab @tab X
317 @item id RoQ DPCM @tab X @tab X
318 @tab Used in Quake III, Jedi Knight 2, other computer games.
319 @item Interplay MVE DPCM @tab @tab X
320 @tab Used in various Interplay computer games.
321 @item Xan DPCM @tab @tab X
322 @tab Used in Origin's Wing Commander IV AVI files.
323 @item Sierra Online DPCM @tab @tab X
324 @tab Used in Sierra Online game audio files.
325 @item Apple MACE 3 @tab @tab X
326 @item Apple MACE 6 @tab @tab X
327 @item FLAC lossless audio @tab X @tab X
328 @item Shorten lossless audio @tab @tab X
329 @item Apple lossless audio @tab @tab X
330 @tab QuickTime fourcc 'alac'
331 @item FFmpeg Sonic @tab X @tab X
332 @tab experimental lossy/lossless codec
333 @item Qdesign QDM2 @tab @tab X
334 @tab there are still some distortions
335 @item Real COOK @tab @tab X
336 @tab All versions except 5.1 are supported
337 @item DSP Group TrueSpeech @tab @tab X
338 @item True Audio (TTA) @tab @tab X
339 @item Smacker Audio @tab @tab X
340 @item WavPack Audio @tab @tab X
341 @item Cin Audio @tab @tab X
342 @tab Codec used in Delphine Software games.
343 @item Intel Music Coder @tab @tab X
344 @item Musepack @tab @tab X
345 @tab SV7 and SV8 are supported
346 @item DTS Coherent Audio @tab @tab X
347 @item ATRAC 3 @tab @tab X
348 @item Monkey's Audio @tab @tab X @tab Only versions 3.97-3.99 are supported
349 @item Nellymoser ASAO @tab @tab X
350 @item 8SVX Audio @tab @tab X
351 @item MLP/TrueHD @tab @tab X @tab Used in DVD-Audio and Blu-Ray discs.
352 @end multitable
354 @code{X} means that encoding (resp. decoding) is supported.
356 @code{I} means that an integer-only version is available, too (ensures high
357 performance on systems without hardware floating point support).
359 @chapter Platform Specific information
361 @section BSD
363 BSD make will not build FFmpeg, you need to install and use GNU Make
364 (@file{gmake}).
366 @section Windows
368 To get help and instructions for building FFmpeg under Windows, check out
369 the FFmpeg Windows Help Forum at
370 @url{http://arrozcru.no-ip.org/ffmpeg/}.
372 @subsection Native Windows compilation
374 FFmpeg can be built to run natively on Windows using the MinGW tools. Install
375 the current versions of MSYS and MinGW from @url{http://www.mingw.org/}. Also
376 install the coreutils package, and update to the latest MSYS make (note: not
377 mingw32-make). You can find detailed installation
378 instructions in the download section and the FAQ.
380 Within the MSYS shell, configure and make with:
382 @example
383 ./configure --enable-memalign-hack
384 make
385 make install
386 @end example
388 This will install @file{ffmpeg.exe} along with many other development files
389 to @file{/usr/local}. You may specify another install path using the
390 @code{--prefix} option in @file{configure}.
392 Notes:
394 @itemize
396 @item Use at least bash 3.1. Older versions are known to fail on the
397 configure script.
399 @item In order to compile vhooks, you must have a POSIX-compliant libdl in
400 your MinGW system. Get dlfcn-win32 from
401 @url{http://code.google.com/p/dlfcn-win32}.
403 @item In order to compile FFplay, you must have the MinGW development library
404 of SDL. Get it from @url{http://www.libsdl.org}.
405 Edit the @file{bin/sdl-config} script so that it points to the correct prefix
406 where SDL was installed. Verify that @file{sdl-config} can be launched from
407 the MSYS command line.
409 @item By using @code{./configure --enable-shared} when configuring FFmpeg,
410 you can build libavutil, libavcodec and libavformat as DLLs.
412 @end itemize
414 @subsection Microsoft Visual C++ compatibility
416 As stated in the FAQ, FFmpeg will not compile under MSVC++. However, if you
417 want to use the libav* libraries in your own applications, you can still
418 compile those applications using MSVC++. But the libav* libraries you link
419 to @emph{must} be built with MinGW. However, you will not be able to debug
420 inside the libav* libraries, since MSVC++ does not recognize the debug
421 symbols generated by GCC.
422 We strongly recommend you to move over from MSVC++ to MinGW tools.
424 This description of how to use the FFmpeg libraries with MSVC++ is based on
425 Microsoft Visual C++ 2005 Express Edition. If you have a different version,
426 you might have to modify the procedures slightly.
428 @subsubsection Using static libraries
430 Assuming you have just built and installed FFmpeg in @file{/usr/local}.
432 @enumerate
434 @item Create a new console application ("File / New / Project") and then
435 select "Win32 Console Application". On the appropriate page of the
436 Application Wizard, uncheck the "Precompiled headers" option.
438 @item Write the source code for your application, or, for testing, just
439 copy the code from an existing sample application into the source file
440 that MSVC++ has already created for you. For example, you can copy
441 @file{output_example.c} from the FFmpeg distribution.
443 @item Open the "Project / Properties" dialog box. In the "Configuration"
444 combo box, select "All Configurations" so that the changes you make will
445 affect both debug and release builds. In the tree view on the left hand
446 side, select "C/C++ / General", then edit the "Additional Include
447 Directories" setting to contain the path where the FFmpeg includes were
448 installed (i.e. @file{c:\msys\1.0\local\include}).
449 Do not add MinGW's include directory here, or the include files will
450 conflict with MSVC's.
452 @item Still in the "Project / Properties" dialog box, select
453 "Linker / General" from the tree view and edit the
454 "Additional Library Directories" setting to contain the @file{lib}
455 directory where FFmpeg was installed (i.e. @file{c:\msys\1.0\local\lib}),
456 the directory where MinGW libs are installed (i.e. @file{c:\mingw\lib}),
457 and the directory where MinGW's GCC libs are installed
458 (i.e. @file{C:\mingw\lib\gcc\mingw32\4.2.1-sjlj}). Then select
459 "Linker / Input" from the tree view, and add the files @file{libavformat.a},
460 @file{libavcodec.a}, @file{libavutil.a}, @file{libmingwex.a},
461 @file{libgcc.a}, and any other libraries you used (i.e. @file{libz.a})
462 to the end of "Additional Dependencies".
464 @item Now, select "C/C++ / Code Generation" from the tree view. Select
465 "Debug" in the "Configuration" combo box. Make sure that "Runtime
466 Library" is set to "Multi-threaded Debug DLL". Then, select "Release" in
467 the "Configuration" combo box and make sure that "Runtime Library" is
468 set to "Multi-threaded DLL".
470 @item Click "OK" to close the "Project / Properties" dialog box.
472 @item MSVC++ lacks some C99 header files that are fundamental for FFmpeg.
473 Get msinttypes from @url{http://code.google.com/p/msinttypes/downloads/list}
474 and install it in MSVC++'s include directory
475 (i.e. @file{C:\Program Files\Microsoft Visual Studio 8\VC\include}).
477 @item MSVC++ also does not understand the @code{inline} keyword used by
478 FFmpeg, so you must add this line before @code{#include}ing libav*:
479 @example
480 #define inline _inline
481 @end example
483 @item Build your application, everything should work.
485 @end enumerate
487 @subsubsection Using shared libraries
489 This is how to create DLL and LIB files that are compatible with MSVC++:
491 @enumerate
493 @item Add a call to @file{vcvars32.bat} (which sets up the environment
494 variables for the Visual C++ tools) as the first line of @file{msys.bat}.
495 The standard location for @file{vcvars32.bat} is
496 @file{C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat},
497 and the standard location for @file{msys.bat} is @file{C:\msys\1.0\msys.bat}.
498 If this corresponds to your setup, add the following line as the first line
499 of @file{msys.bat}:
501 @example
502 call "C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat"
503 @end example
505 Alternatively, you may start the @file{Visual Studio 2005 Command Prompt},
506 and run @file{c:\msys\1.0\msys.bat} from there.
508 @item Within the MSYS shell, run @code{lib.exe}. If you get a help message
509 from @file{Microsoft (R) Library Manager}, this means your environment
510 variables are set up correctly, the @file{Microsoft (R) Library Manager}
511 is on the path and will be used by FFmpeg to create
512 MSVC++-compatible import libraries.
514 @item Build FFmpeg with
516 @example
517 ./configure --enable-shared --enable-memalign-hack
518 make
519 make install
520 @end example
522 Your install path (@file{/usr/local/} by default) should now have the
523 necessary DLL and LIB files under the @file{bin} directory.
525 @end enumerate
527 To use those files with MSVC++, do the same as you would do with
528 the static libraries, as described above. But in Step 4,
529 you should only need to add the directory where the LIB files are installed
530 (i.e. @file{c:\msys\usr\local\bin}). This is not a typo, the LIB files are
531 installed in the @file{bin} directory. And instead of adding @file{libxx.a}
532 files, you should add @file{avcodec.lib}, @file{avformat.lib}, and
533 @file{avutil.lib}. There should be no need for @file{libmingwex.a},
534 @file{libgcc.a}, and @file{wsock32.lib}, nor any other external library
535 statically linked into the DLLs. The @file{bin} directory contains a bunch
536 of DLL files, but the ones that are actually used to run your application
537 are the ones with a major version number in their filenames
538 (i.e. @file{avcodec-51.dll}).
540 @subsection Cross compilation for Windows with Linux
542 You must use the MinGW cross compilation tools available at
543 @url{http://www.mingw.org/}.
545 Then configure FFmpeg with the following options:
546 @example
547 ./configure --target-os=mingw32 --cross-prefix=i386-mingw32msvc-
548 @end example
549 (you can change the cross-prefix according to the prefix chosen for the
550 MinGW tools).
552 Then you can easily test FFmpeg with Wine
553 (@url{http://www.winehq.com/}).
555 @subsection Compilation under Cygwin
557 The main issue with Cygwin is that newlib, its C library, does not
558 contain llrint(). However, it is possible to leverage the
559 implementation in MinGW.
561 Just install your Cygwin with all the "Base" packages, plus the
562 following "Devel" ones:
563 @example
564 binutils, gcc-core, make, subversion, mingw-runtime
565 @end example
567 Do not install binutils-20060709-1 (they are buggy on shared builds);
568 use binutils-20050610-1 instead.
570 Then create a small library that just contains llrint():
572 @example
573 ar x /usr/lib/mingw/libmingwex.a llrint.o
574 ar cq /usr/local/lib/libllrint.a llrint.o
575 @end example
577 Then run
579 @example
580 ./configure --enable-static --disable-shared --extra-ldflags='-L /usr/local/lib' --extra-libs='-l llrint'
581 @end example
583 to make a static build or
585 @example
586 ./configure --enable-shared --disable-static --extra-ldflags='-L /usr/local/lib' --extra-libs='-l llrint'
587 @end example
589 to build shared libraries.
591 If you want to build FFmpeg with additional libraries, download Cygwin
592 "Devel" packages for Ogg and Vorbis from any Cygwin packages repository
593 and/or SDL, xvid, faac, faad2 packages from Cygwin Ports,
594 (@url{http://cygwinports.dotsrc.org/}).
596 @subsection Crosscompilation for Windows under Cygwin
598 With Cygwin you can create Windows binaries that do not need the cygwin1.dll.
600 Just install your Cygwin as explained before, plus these additional
601 "Devel" packages:
602 @example
603 gcc-mingw-core, mingw-runtime, mingw-zlib
604 @end example
606 and add some special flags to your configure invocation.
608 For a static build run
609 @example
610 ./configure --target-os=mingw32 --enable-memalign-hack --enable-static --disable-shared --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
611 @end example
613 and for a build with shared libraries
614 @example
615 ./configure --target-os=mingw32 --enable-memalign-hack --enable-shared --disable-static --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
616 @end example
618 @section BeOS
620 BeOS support is broken in mysterious ways.
622 @section OS/2
624 For information about compiling FFmpeg on OS/2 see
625 @url{http://www.edm2.com/index.php/FFmpeg}.
627 @chapter Developers Guide
629 @section API
630 @itemize @bullet
631 @item libavcodec is the library containing the codecs (both encoding and
632 decoding). Look at @file{libavcodec/apiexample.c} to see how to use it.
634 @item libavformat is the library containing the file format handling (mux and
635 demux code for several formats). Look at @file{ffplay.c} to use it in a
636 player. See @file{output_example.c} to use it to generate audio or video
637 streams.
639 @end itemize
641 @section Integrating libavcodec or libavformat in your program
643 You can integrate all the source code of the libraries to link them
644 statically to avoid any version problem. All you need is to provide a
645 'config.mak' and a 'config.h' in the parent directory. See the defines
646 generated by ./configure to understand what is needed.
648 You can use libavcodec or libavformat in your commercial program, but
649 @emph{any patch you make must be published}. The best way to proceed is
650 to send your patches to the FFmpeg mailing list.
652 @node Coding Rules
653 @section Coding Rules
655 FFmpeg is programmed in the ISO C90 language with a few additional
656 features from ISO C99, namely:
657 @itemize @bullet
658 @item
659 the @samp{inline} keyword;
660 @item
661 @samp{//} comments;
662 @item
663 designated struct initializers (@samp{struct s x = @{ .i = 17 @};})
664 @item
665 compound literals (@samp{x = (struct s) @{ 17, 23 @};})
666 @end itemize
668 These features are supported by all compilers we care about, so we will not
669 accept patches to remove their use unless they absolutely do not impair
670 clarity and performance.
672 All code must compile with GCC 2.95 and GCC 3.3. Currently, FFmpeg also
673 compiles with several other compilers, such as the Compaq ccc compiler
674 or Sun Studio 9, and we would like to keep it that way unless it would
675 be exceedingly involved. To ensure compatibility, please do not use any
676 additional C99 features or GCC extensions. Especially watch out for:
677 @itemize @bullet
678 @item
679 mixing statements and declarations;
680 @item
681 @samp{long long} (use @samp{int64_t} instead);
682 @item
683 @samp{__attribute__} not protected by @samp{#ifdef __GNUC__} or similar;
684 @item
685 GCC statement expressions (@samp{(x = (@{ int y = 4; y; @})}).
686 @end itemize
688 Indent size is 4.
689 The presentation is the one specified by 'indent -i4 -kr -nut'.
690 The TAB character is forbidden outside of Makefiles as is any
691 form of trailing whitespace. Commits containing either will be
692 rejected by the Subversion repository.
694 The main priority in FFmpeg is simplicity and small code size in order to
695 minimize the bug count.
697 Comments: Use the JavaDoc/Doxygen
698 format (see examples below) so that code documentation
699 can be generated automatically. All nontrivial functions should have a comment
700 above them explaining what the function does, even if it is just one sentence.
701 All structures and their member variables should be documented, too.
702 @example
703 /**
704 * @@file mpeg.c
705 * MPEG codec.
706 * @@author ...
707 */
709 /**
710 * Summary sentence.
711 * more text ...
712 * ...
713 */
714 typedef struct Foobar@{
715 int var1; /**< var1 description */
716 int var2; ///< var2 description
717 /** var3 description */
718 int var3;
719 @} Foobar;
721 /**
722 * Summary sentence.
723 * more text ...
724 * ...
725 * @@param my_parameter description of my_parameter
726 * @@return return value description
727 */
728 int myfunc(int my_parameter)
729 ...
730 @end example
732 fprintf and printf are forbidden in libavformat and libavcodec,
733 please use av_log() instead.
735 Casts should be used only when necessary. Unneeded parentheses
736 should also be avoided if they don't make the code easier to understand.
738 @section Development Policy
740 @enumerate
741 @item
742 Contributions should be licensed under the LGPL 2.1, including an
743 "or any later version" clause, or the MIT license. GPL 2 including
744 an "or any later version" clause is also acceptable, but LGPL is
745 preferred.
746 @item
747 You must not commit code which breaks FFmpeg! (Meaning unfinished but
748 enabled code which breaks compilation or compiles but does not work or
749 breaks the regression tests)
750 You can commit unfinished stuff (for testing etc), but it must be disabled
751 (#ifdef etc) by default so it does not interfere with other developers'
752 work.
753 @item
754 You do not have to over-test things. If it works for you, and you think it
755 should work for others, then commit. If your code has problems
756 (portability, triggers compiler bugs, unusual environment etc) they will be
757 reported and eventually fixed.
758 @item
759 Do not commit unrelated changes together, split them into self-contained
760 pieces. Also do not forget that if part B depends on part A, but A does not
761 depend on B, then A can and should be committed first and separate from B.
762 Keeping changes well split into self-contained parts makes reviewing and
763 understanding them on the commit log mailing list easier. This also helps
764 in case of debugging later on.
765 Also if you have doubts about splitting or not splitting, do not hesitate to
766 ask/discuss it on the developer mailing list.
767 @item
768 Do not change behavior of the program (renaming options etc) without
769 first discussing it on the ffmpeg-devel mailing list. Do not remove
770 functionality from the code. Just improve!
772 Note: Redundant code can be removed.
773 @item
774 Do not commit changes to the build system (Makefiles, configure script)
775 which change behavior, defaults etc, without asking first. The same
776 applies to compiler warning fixes, trivial looking fixes and to code
777 maintained by other developers. We usually have a reason for doing things
778 the way we do. Send your changes as patches to the ffmpeg-devel mailing
779 list, and if the code maintainers say OK, you may commit. This does not
780 apply to files you wrote and/or maintain.
781 @item
782 We refuse source indentation and other cosmetic changes if they are mixed
783 with functional changes, such commits will be rejected and removed. Every
784 developer has his own indentation style, you should not change it. Of course
785 if you (re)write something, you can use your own style, even though we would
786 prefer if the indentation throughout FFmpeg was consistent (Many projects
787 force a given indentation style - we do not.). If you really need to make
788 indentation changes (try to avoid this), separate them strictly from real
789 changes.
791 NOTE: If you had to put if()@{ .. @} over a large (> 5 lines) chunk of code,
792 then either do NOT change the indentation of the inner part within (do not
793 move it to the right)! or do so in a separate commit
794 @item
795 Always fill out the commit log message. Describe in a few lines what you
796 changed and why. You can refer to mailing list postings if you fix a
797 particular bug. Comments such as "fixed!" or "Changed it." are unacceptable.
798 @item
799 If you apply a patch by someone else, include the name and email address in
800 the log message. Since the ffmpeg-cvslog mailing list is publicly
801 archived you should add some SPAM protection to the email address. Send an
802 answer to ffmpeg-devel (or wherever you got the patch from) saying that
803 you applied the patch.
804 @item
805 When applying patches that have been discussed (at length) on the mailing
806 list, reference the thread in the log message.
807 @item
808 Do NOT commit to code actively maintained by others without permission.
809 Send a patch to ffmpeg-devel instead. If no one answers within a reasonable
810 timeframe (12h for build failures and security fixes, 3 days small changes,
811 1 week for big patches) then commit your patch if you think it is OK.
812 Also note, the maintainer can simply ask for more time to review!
813 @item
814 Subscribe to the ffmpeg-cvslog mailing list. The diffs of all commits
815 are sent there and reviewed by all the other developers. Bugs and possible
816 improvements or general questions regarding commits are discussed there. We
817 expect you to react if problems with your code are uncovered.
818 @item
819 Update the documentation if you change behavior or add features. If you are
820 unsure how best to do this, send a patch to ffmpeg-devel, the documentation
821 maintainer(s) will review and commit your stuff.
822 @item
823 Try to keep important discussions and requests (also) on the public
824 developer mailing list, so that all developers can benefit from them.
825 @item
826 Never write to unallocated memory, never write over the end of arrays,
827 always check values read from some untrusted source before using them
828 as array index or other risky things.
829 @item
830 Remember to check if you need to bump versions for the specific libav
831 parts (libavutil, libavcodec, libavformat) you are changing. You need
832 to change the version integer and the version string.
833 Incrementing the first component means no backward compatibility to
834 previous versions (e.g. removal of a function from the public API).
835 Incrementing the second component means backward compatible change
836 (e.g. addition of a function to the public API).
837 Incrementing the third component means a noteworthy binary compatible
838 change (e.g. encoder bug fix that matters for the decoder).
839 @item
840 If you add a new codec, remember to update the changelog, add it to
841 the supported codecs table in the documentation and bump the second
842 component of the @file{libavcodec} version number appropriately. If
843 it has a fourcc, add it to @file{libavformat/riff.c}, even if it
844 is only a decoder.
845 @item
846 Compiler warnings indicate potential bugs or code with bad style. If a type of
847 warning always points to correct and clean code, that warning should
848 be disabled, not the code changed.
849 Thus the remaining warnings can either be bugs or correct code.
850 If it is a bug, the bug has to be fixed. If it is not, the code should
851 be changed to not generate a warning unless that causes a slowdown
852 or obfuscates the code.
853 @item
854 If you add a new file, give it a proper license header. Do not copy and
855 paste it from a random place, use an existing file as template.
856 @end enumerate
858 We think our rules are not too hard. If you have comments, contact us.
860 Note, these rules are mostly borrowed from the MPlayer project.
862 @section Submitting patches
864 First, (@pxref{Coding Rules}) above if you did not yet.
866 When you submit your patch, try to send a unified diff (diff '-up'
867 option). We cannot read other diffs :-)
869 Also please do not submit a patch which contains several unrelated changes.
870 Split it into separate, self-contained pieces. This does not mean splitting
871 file by file. Instead, make the patch as small as possible while still
872 keeping it as a logical unit that contains an individual change, even
873 if it spans multiple files. This makes reviewing your patches much easier
874 for us and greatly increases your chances of getting your patch applied.
876 Run the regression tests before submitting a patch so that you can
877 verify that there are no big problems.
879 Patches should be posted as base64 encoded attachments (or any other
880 encoding which ensures that the patch will not be trashed during
881 transmission) to the ffmpeg-devel mailing list, see
882 @url{http://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel}
884 It also helps quite a bit if you tell us what the patch does (for example
885 'replaces lrint by lrintf'), and why (for example '*BSD isn't C99 compliant
886 and has no lrint()')
888 Also please if you send several patches, send each patch as a separate mail,
889 do not attach several unrelated patches to the same mail.
891 @section patch submission checklist
893 @enumerate
894 @item
895 Do the regression tests pass with the patch applied?
896 @item
897 Is the patch a unified diff?
898 @item
899 Is the patch against latest FFmpeg SVN?
900 @item
901 Are you subscribed to ffmpeg-dev?
902 (the list is subscribers only due to spam)
903 @item
904 Have you checked that the changes are minimal, so that the same cannot be
905 achieved with a smaller patch and/or simpler final code?
906 @item
907 If the change is to speed critical code, did you benchmark it?
908 @item
909 If you did any benchmarks, did you provide them in the mail?
910 @item
911 Have you checked that the patch does not introduce buffer overflows or
912 other security issues?
913 @item
914 If you add a new demuxer or decoder, have you checked that it does not
915 crash with damaged input (see tools/trasher)?
916 @item
917 Is the patch created from the root of the source tree, so it can be
918 applied with @code{patch -p0}?
919 @item
920 Does the patch not mix functional and cosmetic changes?
921 @item
922 Did you add tabs or trailing whitespace to the code? Both are forbidden.
923 @item
924 Is the patch attached to the email you send?
925 @item
926 Is the mime type of the patch correct? It should be text/x-diff or
927 text/x-patch or at least text/plain and not application/octet-stream.
928 @item
929 If the patch fixes a bug, did you provide a verbose analysis of the bug?
930 @item
931 If the patch fixes a bug, did you provide enough information, including
932 a sample, so the bug can be reproduced and the fix can be verified?
933 Note please do not attach samples >100k to mails but rather provide a
934 URL, you can upload to ftp://upload.mplayerhq.hu
935 @item
936 Did you provide a verbose summary about what the patch does change?
937 @item
938 Did you provide a verbose explanation why it changes things like it does?
939 @item
940 Did you provide a verbose summary of the user visible advantages and
941 disadvantages if the patch is applied?
942 @item
943 Did you provide an example so we can verify the new feature added by the
944 patch easily?
945 @item
946 If you added a new file, did you insert a license header? It should be
947 taken from FFmpeg, not randomly copied and pasted from somewhere else.
948 @item
949 You should maintain alphabetical order in alphabetically ordered lists as
950 long as doing so does not break API/ABI compatibility.
951 @item
952 Lines with similar content should be aligned vertically when doing so
953 improves readability.
954 @item
955 Did you provide a suggestion for a clear commit log message?
956 @item
957 Did you test your decoder or demuxer against damaged data? If no, see
958 tools/trasher and the noise bitstream filter. Your decoder or demuxer
959 should not crash or end in a (near) infinite loop when fed damaged data.
960 @end enumerate
962 @section Patch review process
964 All patches posted to ffmpeg-devel will be reviewed, unless they contain a
965 clear note that the patch is not for SVN.
966 Reviews and comments will be posted as replies to the patch on the
967 mailing list. The patch submitter then has to take care of every comment,
968 that can be by resubmitting a changed patch or by discussion. Resubmitted
969 patches will themselves be reviewed like any other patch. If at some point
970 a patch passes review with no comments then it is approved, that can for
971 simple and small patches happen immediately while large patches will generally
972 have to be changed and reviewed many times before they are approved.
973 After a patch is approved it will be committed to the repository.
975 We will review all submitted patches, but sometimes we are quite busy so
976 especially for large patches this can take several weeks.
978 When resubmitting patches, please do not make any significant changes
979 not related to the comments received during review. Such patches will
980 be rejected. Instead, submit significant changes or new features as
981 separate patches.
983 @section Regression tests
985 Before submitting a patch (or committing to the repository), you should at least
986 test that you did not break anything.
988 The regression tests build a synthetic video stream and a synthetic
989 audio stream. These are then encoded and decoded with all codecs or
990 formats. The CRC (or MD5) of each generated file is recorded in a
991 result file. A 'diff' is launched to compare the reference results and
992 the result file.
994 The regression tests then go on to test the FFserver code with a
995 limited set of streams. It is important that this step runs correctly
996 as well.
998 Run 'make test' to test all the codecs and formats.
1000 Run 'make fulltest' to test all the codecs, formats and FFserver.
1002 [Of course, some patches may change the results of the regression tests. In
1003 this case, the reference results of the regression tests shall be modified
1004 accordingly].
1006 @bye