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  1. \input texinfo @c -*- texinfo -*-
  2. @settitle General Documentation
  3. @titlepage
  4. @sp 7
  5. @center @titlefont{General Documentation}
  6. @sp 3
  7. @end titlepage
  8. @chapter external libraries
  9. FFmpeg can be hooked up with a number of external libraries to add support
  10. for more formats. None of them are used by default, their use has to be
  11. explicitly requested by passing the appropriate flags to @file{./configure}.
  12. @section AMR
  13. AMR comes in two different flavors, WB and NB. FFmpeg can make use of the
  14. AMR WB (floating-point mode) and the AMR NB (floating-point mode) reference
  15. decoders and encoders.
  16. Go to @url{http://www.penguin.cz/~utx/amr} and follow the instructions for
  17. installing the libraries. Then pass @code{--enable-libamr-nb} and/or
  18. @code{--enable-libamr-wb} to configure to enable the libraries.
  19. @chapter Supported File Formats and Codecs
  20. You can use the @code{-formats} option to have an exhaustive list.
  21. @section File Formats
  22. FFmpeg supports the following file formats through the @code{libavformat}
  23. library:
  24. @multitable @columnfractions .4 .1 .1 .4
  25. @item Supported File Format @tab Encoding @tab Decoding @tab Comments
  26. @item MPEG audio @tab X @tab X
  27. @item MPEG-1 systems @tab X @tab X
  28. @tab muxed audio and video
  29. @item MPEG-2 PS @tab X @tab X
  30. @tab also known as @code{VOB} file
  31. @item MPEG-2 TS @tab @tab X
  32. @tab also known as DVB Transport Stream
  33. @item ASF@tab X @tab X
  34. @item AVI@tab X @tab X
  35. @item WAV@tab X @tab X
  36. @item Macromedia Flash@tab X @tab X
  37. @tab Only embedded audio is decoded.
  38. @item FLV @tab X @tab X
  39. @tab Macromedia Flash video files
  40. @item Real Audio and Video @tab X @tab X
  41. @item Raw AC3 @tab X @tab X
  42. @item Raw MJPEG @tab X @tab X
  43. @item Raw MPEG video @tab X @tab X
  44. @item Raw PCM8/16 bits, mulaw/Alaw@tab X @tab X
  45. @item Raw CRI ADX audio @tab X @tab X
  46. @item Raw Shorten audio @tab @tab X
  47. @item SUN AU format @tab X @tab X
  48. @item NUT @tab X @tab X @tab NUT Open Container Format
  49. @item QuickTime @tab X @tab X
  50. @item MPEG-4 @tab X @tab X
  51. @tab MPEG-4 is a variant of QuickTime.
  52. @item Raw MPEG4 video @tab X @tab X
  53. @item DV @tab X @tab X
  54. @item 4xm @tab @tab X
  55. @tab 4X Technologies format, used in some games.
  56. @item Playstation STR @tab @tab X
  57. @item Id RoQ @tab X @tab X
  58. @tab Used in Quake III, Jedi Knight 2, other computer games.
  59. @item Interplay MVE @tab @tab X
  60. @tab Format used in various Interplay computer games.
  61. @item WC3 Movie @tab @tab X
  62. @tab Multimedia format used in Origin's Wing Commander III computer game.
  63. @item Sega FILM/CPK @tab @tab X
  64. @tab Used in many Sega Saturn console games.
  65. @item Westwood Studios VQA/AUD @tab @tab X
  66. @tab Multimedia formats used in Westwood Studios games.
  67. @item Id Cinematic (.cin) @tab @tab X
  68. @tab Used in Quake II.
  69. @item FLIC format @tab @tab X
  70. @tab .fli/.flc files
  71. @item Sierra VMD @tab @tab X
  72. @tab Used in Sierra CD-ROM games.
  73. @item Sierra Online @tab @tab X
  74. @tab .sol files used in Sierra Online games.
  75. @item Matroska @tab X @tab X
  76. @item Electronic Arts Multimedia @tab @tab X
  77. @tab Used in various EA games; files have extensions like WVE and UV2.
  78. @item Nullsoft Video (NSV) format @tab @tab X
  79. @item ADTS AAC audio @tab X @tab X
  80. @item Creative VOC @tab X @tab X @tab Created for the Sound Blaster Pro.
  81. @item American Laser Games MM @tab @tab X
  82. @tab Multimedia format used in games like Mad Dog McCree
  83. @item AVS @tab @tab X
  84. @tab Multimedia format used by the Creature Shock game.
  85. @item Smacker @tab @tab X
  86. @tab Multimedia format used by many games.
  87. @item GXF @tab X @tab X
  88. @tab General eXchange Format SMPTE 360M, used by Thomson Grass Valley playout servers.
  89. @item CIN @tab @tab X
  90. @tab Multimedia format used by Delphine Software games.
  91. @item MXF @tab @tab X
  92. @tab Material eXchange Format SMPTE 377M, used by D-Cinema, broadcast industry.
  93. @item SEQ @tab @tab X
  94. @tab Tiertex .seq files used in the DOS CDROM version of the game Flashback.
  95. @item DXA @tab @tab X
  96. @tab This format is used in non-Windows version of Feeble Files game and
  97. different game cutscenes repacked for use with ScummVM.
  98. @item THP @tab @tab X
  99. @tab Used on the Nintendo GameCube.
  100. @item C93 @tab @tab X
  101. @tab Used in the game Cyberia from Interplay.
  102. @item Bethsoft VID @tab @tab X
  103. @tab Used in some games from Bethesda Softworks.
  104. @item CRYO APC @tab @tab X
  105. @tab Audio format used in some games by CRYO Interactive Entertainment.
  106. @item Monkey's Audio @tab @tab X
  107. @item SIFF @tab @tab X
  108. @tab Audio and video format used in some games by Beam Software
  109. @end multitable
  110. @code{X} means that encoding (resp. decoding) is supported.
  111. @section Image Formats
  112. FFmpeg can read and write images for each frame of a video sequence. The
  113. following image formats are supported:
  114. @multitable @columnfractions .4 .1 .1 .4
  115. @item Supported Image Format @tab Encoding @tab Decoding @tab Comments
  116. @item PGM, PPM @tab X @tab X
  117. @item PAM @tab X @tab X @tab PAM is a PNM extension with alpha support.
  118. @item PGMYUV @tab X @tab X @tab PGM with U and V components in YUV 4:2:0
  119. @item JPEG @tab X @tab X @tab Progressive JPEG is not supported.
  120. @item .Y.U.V @tab X @tab X @tab one raw file per component
  121. @item animated GIF @tab X @tab X @tab Only uncompressed GIFs are generated.
  122. @item PNG @tab X @tab X @tab 2 bit and 4 bit/pixel not supported yet.
  123. @item Targa @tab @tab X @tab Targa (.TGA) image format.
  124. @item TIFF @tab X @tab X @tab YUV, JPEG and some extension is not supported yet.
  125. @item SGI @tab X @tab X @tab SGI RGB image format
  126. @item PTX @tab @tab X @tab V.Flash PTX format
  127. @end multitable
  128. @code{X} means that encoding (resp. decoding) is supported.
  129. @section Video Codecs
  130. @multitable @columnfractions .4 .1 .1 .4
  131. @item Supported Codec @tab Encoding @tab Decoding @tab Comments
  132. @item MPEG-1 video @tab X @tab X
  133. @item MPEG-2 video @tab X @tab X
  134. @item MPEG-4 @tab X @tab X
  135. @item MSMPEG4 V1 @tab X @tab X
  136. @item MSMPEG4 V2 @tab X @tab X
  137. @item MSMPEG4 V3 @tab X @tab X
  138. @item WMV7 @tab X @tab X
  139. @item WMV8 @tab X @tab X @tab not completely working
  140. @item WMV9 @tab @tab X @tab not completely working
  141. @item VC1 @tab @tab X
  142. @item H.261 @tab X @tab X
  143. @item H.263(+) @tab X @tab X @tab also known as RealVideo 1.0
  144. @item H.264 @tab @tab X
  145. @item RealVideo 1.0 @tab X @tab X
  146. @item RealVideo 2.0 @tab X @tab X
  147. @item MJPEG @tab X @tab X
  148. @item lossless MJPEG @tab X @tab X
  149. @item JPEG-LS @tab X @tab X @tab fourcc: MJLS, lossless and near-lossless is supported
  150. @item Apple MJPEG-B @tab @tab X
  151. @item Sunplus MJPEG @tab @tab X @tab fourcc: SP5X
  152. @item DV @tab X @tab X
  153. @item HuffYUV @tab X @tab X
  154. @item FFmpeg Video 1 @tab X @tab X @tab experimental lossless codec (fourcc: FFV1)
  155. @item FFmpeg Snow @tab X @tab X @tab experimental wavelet codec (fourcc: SNOW)
  156. @item Asus v1 @tab X @tab X @tab fourcc: ASV1
  157. @item Asus v2 @tab X @tab X @tab fourcc: ASV2
  158. @item Creative YUV @tab @tab X @tab fourcc: CYUV
  159. @item Sorenson Video 1 @tab X @tab X @tab fourcc: SVQ1
  160. @item Sorenson Video 3 @tab @tab X @tab fourcc: SVQ3
  161. @item On2 VP3 @tab @tab X @tab still experimental
  162. @item On2 VP5 @tab @tab X @tab fourcc: VP50
  163. @item On2 VP6 @tab @tab X @tab fourcc: VP60,VP61,VP62
  164. @item Theora @tab X @tab X @tab still experimental
  165. @item Intel Indeo 3 @tab @tab X
  166. @item FLV @tab X @tab X @tab Sorenson H.263 used in Flash
  167. @item Flash Screen Video @tab X @tab X @tab fourcc: FSV1
  168. @item ATI VCR1 @tab @tab X @tab fourcc: VCR1
  169. @item ATI VCR2 @tab @tab X @tab fourcc: VCR2
  170. @item Cirrus Logic AccuPak @tab @tab X @tab fourcc: CLJR
  171. @item 4X Video @tab @tab X @tab Used in certain computer games.
  172. @item Sony Playstation MDEC @tab @tab X
  173. @item Id RoQ @tab X @tab X @tab Used in Quake III, Jedi Knight 2, other computer games.
  174. @item Xan/WC3 @tab @tab X @tab Used in Wing Commander III .MVE files.
  175. @item Interplay Video @tab @tab X @tab Used in Interplay .MVE files.
  176. @item Apple Animation @tab X @tab X @tab fourcc: 'rle '
  177. @item Apple Graphics @tab @tab X @tab fourcc: 'smc '
  178. @item Apple Video @tab @tab X @tab fourcc: rpza
  179. @item Apple QuickDraw @tab @tab X @tab fourcc: qdrw
  180. @item Cinepak @tab @tab X
  181. @item Microsoft RLE @tab @tab X
  182. @item Microsoft Video-1 @tab @tab X
  183. @item Westwood VQA @tab @tab X
  184. @item Id Cinematic Video @tab @tab X @tab Used in Quake II.
  185. @item Planar RGB @tab @tab X @tab fourcc: 8BPS
  186. @item FLIC video @tab @tab X
  187. @item Duck TrueMotion v1 @tab @tab X @tab fourcc: DUCK
  188. @item Duck TrueMotion v2 @tab @tab X @tab fourcc: TM20
  189. @item VMD Video @tab @tab X @tab Used in Sierra VMD files.
  190. @item MSZH @tab @tab X @tab Part of LCL
  191. @item ZLIB @tab X @tab X @tab Part of LCL, encoder experimental
  192. @item TechSmith Camtasia @tab @tab X @tab fourcc: TSCC
  193. @item IBM Ultimotion @tab @tab X @tab fourcc: ULTI
  194. @item Miro VideoXL @tab @tab X @tab fourcc: VIXL
  195. @item QPEG @tab @tab X @tab fourccs: QPEG, Q1.0, Q1.1
  196. @item LOCO @tab @tab X @tab
  197. @item Winnov WNV1 @tab @tab X @tab
  198. @item Autodesk Animator Studio Codec @tab @tab X @tab fourcc: AASC
  199. @item Fraps FPS1 @tab @tab X @tab
  200. @item CamStudio @tab @tab X @tab fourcc: CSCD
  201. @item American Laser Games Video @tab @tab X @tab Used in games like Mad Dog McCree
  202. @item ZMBV @tab X @tab X @tab Encoder works only on PAL8
  203. @item AVS Video @tab @tab X @tab Video encoding used by the Creature Shock game.
  204. @item Smacker Video @tab @tab X @tab Video encoding used in Smacker.
  205. @item RTjpeg @tab @tab X @tab Video encoding used in NuppelVideo files.
  206. @item KMVC @tab @tab X @tab Codec used in Worms games.
  207. @item VMware Video @tab @tab X @tab Codec used in videos captured by VMware.
  208. @item Cin Video @tab @tab X @tab Codec used in Delphine Software games.
  209. @item Tiertex Seq Video @tab @tab X @tab Codec used in DOS CDROM FlashBack game.
  210. @item DXA Video @tab @tab X @tab Codec originally used in Feeble Files game.
  211. @item AVID DNxHD @tab X @tab X @tab aka SMPTE VC3
  212. @item C93 Video @tab @tab X @tab Codec used in Cyberia game.
  213. @item THP @tab @tab X @tab Used on the Nintendo GameCube.
  214. @item Bethsoft VID @tab @tab X @tab Used in some games from Bethesda Softworks.
  215. @item Renderware TXD @tab @tab X @tab Texture dictionaries used by the Renderware Engine.
  216. @item AMV @tab @tab X @tab Used in Chinese MP3 players.
  217. @end multitable
  218. @code{X} means that encoding (resp. decoding) is supported.
  219. @section Audio Codecs
  220. @multitable @columnfractions .4 .1 .1 .1 .7
  221. @item Supported Codec @tab Encoding @tab Decoding @tab Comments
  222. @item MPEG audio layer 2 @tab IX @tab IX
  223. @item MPEG audio layer 1/3 @tab X @tab IX
  224. @tab MP3 encoding is supported through the external library LAME.
  225. @item AC3 @tab IX @tab IX
  226. @tab liba52 is used internally for decoding.
  227. @item Vorbis @tab X @tab X
  228. @item WMA V1/V2 @tab X @tab X
  229. @item AAC @tab X @tab X
  230. @tab Supported through the external library libfaac/libfaad.
  231. @item Microsoft ADPCM @tab X @tab X
  232. @item AMV IMA ADPCM @tab @tab X
  233. @tab Used in AMV files
  234. @item MS IMA ADPCM @tab X @tab X
  235. @item QT IMA ADPCM @tab @tab X
  236. @item 4X IMA ADPCM @tab @tab X
  237. @item G.726 ADPCM @tab X @tab X
  238. @item Duck DK3 IMA ADPCM @tab @tab X
  239. @tab Used in some Sega Saturn console games.
  240. @item Duck DK4 IMA ADPCM @tab @tab X
  241. @tab Used in some Sega Saturn console games.
  242. @item Westwood Studios IMA ADPCM @tab @tab X
  243. @tab Used in Westwood Studios games like Command and Conquer.
  244. @item SMJPEG IMA ADPCM @tab @tab X
  245. @tab Used in certain Loki game ports.
  246. @item CD-ROM XA ADPCM @tab @tab X
  247. @item CRI ADX ADPCM @tab X @tab X
  248. @tab Used in Sega Dreamcast games.
  249. @item Electronic Arts ADPCM @tab @tab X
  250. @tab Used in various EA titles.
  251. @item Creative ADPCM @tab @tab X
  252. @tab 16 -> 4, 8 -> 4, 8 -> 3, 8 -> 2
  253. @item THP ADPCM @tab @tab X
  254. @tab Used on the Nintendo GameCube.
  255. @item RA144 @tab @tab X
  256. @tab Real 14400 bit/s codec
  257. @item RA288 @tab @tab X
  258. @tab Real 28800 bit/s codec
  259. @item RADnet @tab X @tab IX
  260. @tab Real low bitrate AC3 codec, liba52 is used for decoding.
  261. @item AMR-NB @tab X @tab X
  262. @tab Supported through an external library.
  263. @item AMR-WB @tab X @tab X
  264. @tab Supported through an external library.
  265. @item DV audio @tab @tab X
  266. @item Id RoQ DPCM @tab X @tab X
  267. @tab Used in Quake III, Jedi Knight 2, other computer games.
  268. @item Interplay MVE DPCM @tab @tab X
  269. @tab Used in various Interplay computer games.
  270. @item Xan DPCM @tab @tab X
  271. @tab Used in Origin's Wing Commander IV AVI files.
  272. @item Sierra Online DPCM @tab @tab X
  273. @tab Used in Sierra Online game audio files.
  274. @item Apple MACE 3 @tab @tab X
  275. @item Apple MACE 6 @tab @tab X
  276. @item FLAC lossless audio @tab X @tab X
  277. @item Shorten lossless audio @tab @tab X
  278. @item Apple lossless audio @tab @tab X
  279. @tab QuickTime fourcc 'alac'
  280. @item FFmpeg Sonic @tab X @tab X
  281. @tab experimental lossy/lossless codec
  282. @item Qdesign QDM2 @tab @tab X
  283. @tab there are still some distortions
  284. @item Real COOK @tab @tab X
  285. @tab All versions except 5.1 are supported
  286. @item DSP Group TrueSpeech @tab @tab X
  287. @item True Audio (TTA) @tab @tab X
  288. @item Smacker Audio @tab @tab X
  289. @item WavPack Audio @tab @tab X
  290. @item Cin Audio @tab @tab X
  291. @tab Codec used in Delphine Software games.
  292. @item Intel Music Coder @tab @tab X
  293. @item Musepack @tab @tab X
  294. @tab SV7 and SV8 are supported
  295. @item DT$ Coherent Audio @tab @tab X
  296. @item ATRAC 3 @tab @tab X
  297. @item Monkey's Audio @tab @tab X @tab Only versions 3.97-3.99 are supported
  298. @item Nellymoser ASAO @tab @tab X
  299. @end multitable
  300. @code{X} means that encoding (resp. decoding) is supported.
  301. @code{I} means that an integer-only version is available, too (ensures high
  302. performance on systems without hardware floating point support).
  303. @chapter Platform Specific information
  304. @section BSD
  305. BSD make will not build FFmpeg, you need to install and use GNU Make
  306. (@file{gmake}).
  307. @section Windows
  308. To get help and instructions for building FFmpeg under Windows, check out
  309. the FFmpeg Windows Help Forum at
  310. @url{http://arrozcru.no-ip.org/ffmpeg/}.
  311. @subsection Native Windows compilation
  312. FFmpeg can be built to run natively on Windows using the MinGW tools. Install
  313. the current versions of MSYS and MinGW from @url{http://www.mingw.org/}. Also
  314. install the coreutils package. You can find detailed installation
  315. instructions in the download section and the FAQ.
  316. Within the MSYS shell, configure and make with:
  317. @example
  318. ./configure --enable-memalign-hack
  319. make
  320. make install
  321. @end example
  322. This will install @file{ffmpeg.exe} along with many other development files
  323. to @file{/usr/local}. You may specify another install path using the
  324. @code{--prefix} option in @file{configure}.
  325. Notes:
  326. @itemize
  327. @item Use at least bash 3.1. Older versions are known to be fail on the
  328. configure script.
  329. @item In order to compile vhooks, you must have a POSIX-compliant libdl in
  330. your MinGW system. Get dlfcn-win32 from
  331. @url{http://code.google.com/p/dlfcn-win32}.
  332. @item In order to compile FFplay, you must have the MinGW development library
  333. of SDL. Get it from @url{http://www.libsdl.org}.
  334. Edit the @file{bin/sdl-config} script so that it points to the correct prefix
  335. where SDL was installed. Verify that @file{sdl-config} can be launched from
  336. the MSYS command line.
  337. @item The target @code{make wininstaller} can be used to create a
  338. Nullsoft-based Windows installer for FFmpeg and FFplay. @file{SDL.dll}
  339. must be copied to the FFmpeg directory in order to build the
  340. installer.
  341. @item By using @code{./configure --enable-shared} when configuring FFmpeg,
  342. you can build libavutil, libavcodec and libavformat as DLLs.
  343. @end itemize
  344. @subsection Microsoft Visual C++ compatibility
  345. As stated in the FAQ, FFmpeg will not compile under MSVC++. However, if you
  346. want to use the libav* libraries in your own applications, you can still
  347. compile those applications using MSVC++. But the libav* libraries you link
  348. to @emph{must} be built with MinGW. However, you will not be able to debug
  349. inside the libav* libraries, since MSVC++ does not recognize the debug
  350. symbols generated by GCC.
  351. We strongly recommend you to move over from MSVC++ to MinGW tools.
  352. This description of how to use the FFmpeg libraries with MSVC++ is based on
  353. Microsoft Visual C++ 2005 Express Edition. If you have a different version,
  354. you might have to modify the procedures slightly.
  355. @subsubsection Using static libraries
  356. Assuming you have just built and installed FFmpeg in @file{/usr/local}.
  357. @enumerate
  358. @item Create a new console application ("File / New / Project") and then
  359. select "Win32 Console Application". On the appropriate page of the
  360. Application Wizard, uncheck the "Precompiled headers" option.
  361. @item Write the source code for your application, or, for testing, just
  362. copy the code from an existing sample application into the source file
  363. that MSVC++ has already created for you. For example, you can copy
  364. @file{output_example.c} from the FFmpeg distribution.
  365. @item Open the "Project / Properties" dialog box. In the "Configuration"
  366. combo box, select "All Configurations" so that the changes you make will
  367. affect both debug and release builds. In the tree view on the left hand
  368. side, select "C/C++ / General", then edit the "Additional Include
  369. Directories" setting to contain the path where the FFmpeg includes were
  370. installed (i.e. @file{c:\msys\1.0\local\include}).
  371. @item Still in the "Project / Properties" dialog box, select
  372. "Linker / General" from the tree view and edit the
  373. "Additional Library Directories" setting to contain the @file{lib}
  374. directory where FFmpeg was installed (i.e. @file{c:\msys\1.0\local\lib}),
  375. the directory where MinGW libs are installed (i.e. @file{c:\mingw\lib}),
  376. and the directory where MinGW's GCC libs are installed
  377. (i.e. @file{C:\mingw\lib\gcc\mingw32\4.2.1-sjlj}). Then select
  378. "Linker / Input" from the tree view, and add the files @file{libavformat.a},
  379. @file{libavcodec.a}, @file{libavutil.a}, @file{libmingwex.a},
  380. @file{libgcc.a}, and any other libraries you used (i.e. @file{libz.a})
  381. to the end of "Additional Dependencies".
  382. @item Now, select "C/C++ / Code Generation" from the tree view. Select
  383. "Debug" in the "Configuration" combo box. Make sure that "Runtime
  384. Library" is set to "Multi-threaded Debug DLL". Then, select "Release" in
  385. the "Configuration" combo box and make sure that "Runtime Library" is
  386. set to "Multi-threaded DLL".
  387. @item Click "OK" to close the "Project / Properties" dialog box.
  388. @item MSVC++ lacks some C99 header files that are fundamental for FFmpeg.
  389. Get msinttypes from @url{http://code.google.com/p/msinttypes/downloads/list}
  390. and install it in MSVC++'s include directory
  391. (i.e. @file{C:\Program Files\Microsoft Visual Studio 8\VC\include}).
  392. @item MSVC++ also does not understand the @code{inline} keyword used by
  393. FFmpeg, so you must add this line before @code{#include}ing libav*:
  394. @example
  395. #define inline _inline
  396. @end example
  397. @item If you used @file{output_example.c} as your sample application,
  398. you will have to edit the @code{#include}s to point to the files which
  399. are under the @file{ffmpeg} directory (i.e. @code{<ffmpeg/avformat.h>}).
  400. @item Build your application, everything should work.
  401. @end enumerate
  402. @subsubsection Using shared libraries
  403. This is how to create DLL and LIB files that are compatible with MSVC++:
  404. @enumerate
  405. @item Add a call to @file{vcvars32.bat} (which sets up the environment
  406. variables for the Visual C++ tools) as the first line of @file{msys.bat}.
  407. The standard location for @file{vcvars32.bat} is
  408. @file{C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat},
  409. and the standard location for @file{msys.bat} is @file{C:\msys\1.0\msys.bat}.
  410. If this corresponds to your setup, add the following line as the first line
  411. of @file{msys.bat}:
  412. @example
  413. call "C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat"
  414. @end example
  415. Alternatively, you may start the @file{Visual Studio 2005 Command Prompt},
  416. and run @file{c:\msys\1.0\msys.bat} from there.
  417. @item Within the MSYS shell, run @code{lib.exe}. If you get a help message
  418. from @file{Microsoft (R) Library Manager}, this means your environment
  419. variables are set up correctly, the @file{Microsoft (R) Library Manager}
  420. is on the path and will be used by FFmpeg to create
  421. MSVC++-compatible import libraries.
  422. @item Build FFmpeg with
  423. @example
  424. ./configure --enable-shared --enable-memalign-hack
  425. make
  426. make install
  427. @end example
  428. Your install path (@file{/usr/local/} by default) should now have the
  429. necessary DLL and LIB files under the @file{bin} directory.
  430. @end enumerate
  431. To use those files with MSVC++, do the same as you would do with
  432. the static libraries, as described above. But in Step 4,
  433. you should only need to add the directory where the LIB files are installed
  434. (i.e. @file{c:\msys\usr\local\bin}). This is not a typo, the LIB files are
  435. installed in the @file{bin} directory. And instead of adding @file{libxx.a}
  436. files, you should add @file{avcodec.lib}, @file{avformat.lib}, and
  437. @file{avutil.lib}. There should be no need for @file{libmingwex.a},
  438. @file{libgcc.a}, and @file{wsock32.lib}, nor any other external library
  439. statically linked into the DLLs. The @file{bin} directory contains a bunch
  440. of DLL files, but the ones that are actually used to run your application
  441. are the ones with a major version number in their filenames
  442. (i.e. @file{avcodec-51.dll}).
  443. @subsection Cross compilation for Windows with Linux
  444. You must use the MinGW cross compilation tools available at
  445. @url{http://www.mingw.org/}.
  446. Then configure FFmpeg with the following options:
  447. @example
  448. ./configure --target-os=mingw32 --cross-prefix=i386-mingw32msvc-
  449. @end example
  450. (you can change the cross-prefix according to the prefix chosen for the
  451. MinGW tools).
  452. Then you can easily test FFmpeg with Wine
  453. (@url{http://www.winehq.com/}).
  454. @subsection Compilation under Cygwin
  455. The main issue with Cygwin is that newlib, its C library, does not
  456. contain llrint(). However, it is possible to leverage the
  457. implementation in MinGW.
  458. Just install your Cygwin with all the "Base" packages, plus the
  459. following "Devel" ones:
  460. @example
  461. binutils, gcc-core, make, subversion, mingw-runtime
  462. @end example
  463. Do not install binutils-20060709-1 (they are buggy on shared builds);
  464. use binutils-20050610-1 instead.
  465. Then create a small library that just contains llrint():
  466. @example
  467. ar x /usr/lib/mingw/libmingwex.a llrint.o
  468. ar cq /usr/local/lib/libllrint.a llrint.o
  469. @end example
  470. Then run
  471. @example
  472. ./configure --enable-static --disable-shared --extra-ldflags='-L /usr/local/lib' --extra-libs='-l llrint'
  473. @end example
  474. to make a static build or
  475. @example
  476. ./configure --enable-shared --disable-static --extra-ldflags='-L /usr/local/lib' --extra-libs='-l llrint'
  477. @end example
  478. to build shared libraries.
  479. If you want to build FFmpeg with additional libraries, download Cygwin
  480. "Devel" packages for Ogg and Vorbis from any Cygwin packages repository
  481. and/or SDL, xvid, faac, faad2 packages from Cygwin Ports,
  482. (@url{http://cygwinports.dotsrc.org/}).
  483. @subsection Crosscompilation for Windows under Cygwin
  484. With Cygwin you can create Windows binaries that do not need the cygwin1.dll.
  485. Just install your Cygwin as explained before, plus these additional
  486. "Devel" packages:
  487. @example
  488. gcc-mingw-core, mingw-runtime, mingw-zlib
  489. @end example
  490. and add some special flags to your configure invocation.
  491. For a static build run
  492. @example
  493. ./configure --target-os=mingw32 --enable-memalign-hack --enable-static --disable-shared --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
  494. @end example
  495. and for a build with shared libraries
  496. @example
  497. ./configure --target-os=mingw32 --enable-memalign-hack --enable-shared --disable-static --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
  498. @end example
  499. @section BeOS
  500. BeOS support is broken in mysterious ways.
  501. @chapter Developers Guide
  502. @section API
  503. @itemize @bullet
  504. @item libavcodec is the library containing the codecs (both encoding and
  505. decoding). Look at @file{libavcodec/apiexample.c} to see how to use it.
  506. @item libavformat is the library containing the file format handling (mux and
  507. demux code for several formats). Look at @file{ffplay.c} to use it in a
  508. player. See @file{output_example.c} to use it to generate audio or video
  509. streams.
  510. @end itemize
  511. @section Integrating libavcodec or libavformat in your program
  512. You can integrate all the source code of the libraries to link them
  513. statically to avoid any version problem. All you need is to provide a
  514. 'config.mak' and a 'config.h' in the parent directory. See the defines
  515. generated by ./configure to understand what is needed.
  516. You can use libavcodec or libavformat in your commercial program, but
  517. @emph{any patch you make must be published}. The best way to proceed is
  518. to send your patches to the FFmpeg mailing list.
  519. @node Coding Rules
  520. @section Coding Rules
  521. FFmpeg is programmed in the ISO C90 language with a few additional
  522. features from ISO C99, namely:
  523. @itemize @bullet
  524. @item
  525. the @samp{inline} keyword;
  526. @item
  527. @samp{//} comments;
  528. @item
  529. designated struct initializers (@samp{struct s x = @{ .i = 17 @};})
  530. @item
  531. compound literals (@samp{x = (struct s) @{ 17, 23 @};})
  532. @end itemize
  533. These features are supported by all compilers we care about, so we will not
  534. accept patches to remove their use unless they absolutely do not impair
  535. clarity and performance.
  536. All code must compile with GCC 2.95 and GCC 3.3. Currently, FFmpeg also
  537. compiles with several other compilers, such as the Compaq ccc compiler
  538. or Sun Studio 9, and we would like to keep it that way unless it would
  539. be exceedingly involved. To ensure compatibility, please do not use any
  540. additional C99 features or GCC extensions. Especially watch out for:
  541. @itemize @bullet
  542. @item
  543. mixing statements and declarations;
  544. @item
  545. @samp{long long} (use @samp{int64_t} instead);
  546. @item
  547. @samp{__attribute__} not protected by @samp{#ifdef __GNUC__} or similar;
  548. @item
  549. GCC statement expressions (@samp{(x = (@{ int y = 4; y; @})}).
  550. @end itemize
  551. Indent size is 4.
  552. The presentation is the one specified by 'indent -i4 -kr -nut'.
  553. The TAB character is forbidden outside of Makefiles as is any
  554. form of trailing whitespace. Commits containing either will be
  555. rejected by the Subversion repository.
  556. The main priority in FFmpeg is simplicity and small code size in order to
  557. minimize the bug count.
  558. Comments: Use the JavaDoc/Doxygen
  559. format (see examples below) so that code documentation
  560. can be generated automatically. All nontrivial functions should have a comment
  561. above them explaining what the function does, even if it is just one sentence.
  562. All structures and their member variables should be documented, too.
  563. @example
  564. /**
  565. * @@file mpeg.c
  566. * MPEG codec.
  567. * @@author ...
  568. */
  569. /**
  570. * Summary sentence.
  571. * more text ...
  572. * ...
  573. */
  574. typedef struct Foobar@{
  575. int var1; /**< var1 description */
  576. int var2; ///< var2 description
  577. /** var3 description */
  578. int var3;
  579. @} Foobar;
  580. /**
  581. * Summary sentence.
  582. * more text ...
  583. * ...
  584. * @@param my_parameter description of my_parameter
  585. * @@return return value description
  586. */
  587. int myfunc(int my_parameter)
  588. ...
  589. @end example
  590. fprintf and printf are forbidden in libavformat and libavcodec,
  591. please use av_log() instead.
  592. Casts should be used only when necessary. Unneeded parentheses
  593. should also be avoided if they don't make the code easier to understand.
  594. @section Development Policy
  595. @enumerate
  596. @item
  597. Contributions should be licensed under the LGPL 2.1, including an
  598. "or any later version" clause, or the MIT license. GPL 2 including
  599. an "or any later version" clause is also acceptable, but LGPL is
  600. preferred.
  601. @item
  602. You must not commit code which breaks FFmpeg! (Meaning unfinished but
  603. enabled code which breaks compilation or compiles but does not work or
  604. breaks the regression tests)
  605. You can commit unfinished stuff (for testing etc), but it must be disabled
  606. (#ifdef etc) by default so it does not interfere with other developers'
  607. work.
  608. @item
  609. You do not have to over-test things. If it works for you, and you think it
  610. should work for others, then commit. If your code has problems
  611. (portability, triggers compiler bugs, unusual environment etc) they will be
  612. reported and eventually fixed.
  613. @item
  614. Do not commit unrelated changes together, split them into self-contained
  615. pieces. Also do not forget that if part B depends on part A, but A does not
  616. depend on B, then A can and should be committed first and separate from B.
  617. Keeping changes well split into self-contained parts makes reviewing and
  618. understanding them on the commit log mailing list easier. This also helps
  619. in case of debugging later on.
  620. Also if you have doubts about splitting or not splitting, do not hesitate to
  621. ask/discuss it on the developer mailing list.
  622. @item
  623. Do not change behavior of the program (renaming options etc) without
  624. first discussing it on the ffmpeg-devel mailing list. Do not remove
  625. functionality from the code. Just improve!
  626. Note: Redundant code can be removed.
  627. @item
  628. Do not commit changes to the build system (Makefiles, configure script)
  629. which change behavior, defaults etc, without asking first. The same
  630. applies to compiler warning fixes, trivial looking fixes and to code
  631. maintained by other developers. We usually have a reason for doing things
  632. the way we do. Send your changes as patches to the ffmpeg-devel mailing
  633. list, and if the code maintainers say OK, you may commit. This does not
  634. apply to files you wrote and/or maintain.
  635. @item
  636. We refuse source indentation and other cosmetic changes if they are mixed
  637. with functional changes, such commits will be rejected and removed. Every
  638. developer has his own indentation style, you should not change it. Of course
  639. if you (re)write something, you can use your own style, even though we would
  640. prefer if the indentation throughout FFmpeg was consistent (Many projects
  641. force a given indentation style - we do not.). If you really need to make
  642. indentation changes (try to avoid this), separate them strictly from real
  643. changes.
  644. NOTE: If you had to put if()@{ .. @} over a large (> 5 lines) chunk of code,
  645. then either do NOT change the indentation of the inner part within (do not
  646. move it to the right)! or do so in a separate commit
  647. @item
  648. Always fill out the commit log message. Describe in a few lines what you
  649. changed and why. You can refer to mailing list postings if you fix a
  650. particular bug. Comments such as "fixed!" or "Changed it." are unacceptable.
  651. @item
  652. If you apply a patch by someone else, include the name and email address in
  653. the log message. Since the ffmpeg-cvslog mailing list is publicly
  654. archived you should add some SPAM protection to the email address. Send an
  655. answer to ffmpeg-devel (or wherever you got the patch from) saying that
  656. you applied the patch.
  657. @item
  658. When applying patches that have been discussed (at length) on the mailing
  659. list, reference the thread in the log message.
  660. @item
  661. Do NOT commit to code actively maintained by others without permission.
  662. Send a patch to ffmpeg-devel instead. If no one answers within a reasonable
  663. timeframe (12h for build failures and security fixes, 3 days small changes,
  664. 1 week for big patches) then commit your patch if you think it is OK.
  665. Also note, the maintainer can simply ask for more time to review!
  666. @item
  667. Subscribe to the ffmpeg-cvslog mailing list. The diffs of all commits
  668. are sent there and reviewed by all the other developers. Bugs and possible
  669. improvements or general questions regarding commits are discussed there. We
  670. expect you to react if problems with your code are uncovered.
  671. @item
  672. Update the documentation if you change behavior or add features. If you are
  673. unsure how best to do this, send a patch to ffmpeg-devel, the documentation
  674. maintainer(s) will review and commit your stuff.
  675. @item
  676. Try to keep important discussions and requests (also) on the public
  677. developer mailing list, so that all developers can benefit from them.
  678. @item
  679. Never write to unallocated memory, never write over the end of arrays,
  680. always check values read from some untrusted source before using them
  681. as array index or other risky things.
  682. @item
  683. Remember to check if you need to bump versions for the specific libav
  684. parts (libavutil, libavcodec, libavformat) you are changing. You need
  685. to change the version integer and the version string.
  686. Incrementing the first component means no backward compatibility to
  687. previous versions (e.g. removal of a function from the public API).
  688. Incrementing the second component means backward compatible change
  689. (e.g. addition of a function to the public API).
  690. Incrementing the third component means a noteworthy binary compatible
  691. change (e.g. encoder bug fix that matters for the decoder).
  692. @item
  693. If you add a new codec, remember to update the changelog, add it to
  694. the supported codecs table in the documentation and bump the second
  695. component of the @file{libavcodec} version number appropriately. If
  696. it has a fourcc, add it to @file{libavformat/avienc.c}, even if it
  697. is only a decoder.
  698. @item
  699. Do not change code to hide warnings without ensuring that the underlying
  700. logic is correct and thus the warning was inappropriate.
  701. @item
  702. If you add a new file, give it a proper license header. Do not copy and
  703. paste it from a random place, use an existing file as template.
  704. @end enumerate
  705. We think our rules are not too hard. If you have comments, contact us.
  706. Note, these rules are mostly borrowed from the MPlayer project.
  707. @section Submitting patches
  708. First, (@pxref{Coding Rules}) above if you did not yet.
  709. When you submit your patch, try to send a unified diff (diff '-up'
  710. option). We cannot read other diffs :-)
  711. Also please do not submit a patch which contains several unrelated changes.
  712. Split it into separate, self-contained pieces. This does not mean splitting
  713. file by file. Instead, make the patch as small as possible while still
  714. keeping it as a logical unit that contains an individual change, even
  715. if it spans multiple files. This makes reviewing your patches much easier
  716. for us and greatly increases your chances of getting your patch applied.
  717. Run the regression tests before submitting a patch so that you can
  718. verify that there are no big problems.
  719. Patches should be posted as base64 encoded attachments (or any other
  720. encoding which ensures that the patch will not be trashed during
  721. transmission) to the ffmpeg-devel mailing list, see
  722. @url{http://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel}
  723. It also helps quite a bit if you tell us what the patch does (for example
  724. 'replaces lrint by lrintf'), and why (for example '*BSD isn't C99 compliant
  725. and has no lrint()')
  726. Also please if you send several patches, send each patch as a separate mail,
  727. do not attach several unrelated patches to the same mail.
  728. @section patch submission checklist
  729. @enumerate
  730. @item
  731. Do the regression tests pass with the patch applied?
  732. @item
  733. Is the patch a unified diff?
  734. @item
  735. Is the patch against latest FFmpeg SVN?
  736. @item
  737. Are you subscribed to ffmpeg-dev?
  738. (the list is subscribers only due to spam)
  739. @item
  740. Have you checked that the changes are minimal, so that the same cannot be
  741. achieved with a smaller patch and/or simpler final code?
  742. @item
  743. If the change is to speed critical code, did you benchmark it?
  744. @item
  745. If you did any benchmarks, did you provide them in the mail?
  746. @item
  747. Have you checked that the patch does not introduce buffer overflows or
  748. other security issues?
  749. @item
  750. Is the patch created from the root of the source tree, so it can be
  751. applied with @code{patch -p0}?
  752. @item
  753. Does the patch not mix functional and cosmetic changes?
  754. @item
  755. Did you add tabs or trailing whitespace to the code? Both are forbidden.
  756. @item
  757. Is the patch attached to the email you send?
  758. @item
  759. Is the mime type of the patch correct? It should be text/x-diff or
  760. text/x-patch or at least text/plain and not application/octet-stream.
  761. @item
  762. If the patch fixes a bug, did you provide a verbose analysis of the bug?
  763. @item
  764. If the patch fixes a bug, did you provide enough information, including
  765. a sample, so the bug can be reproduced and the fix can be verified?
  766. Note please do not attach samples >100k to mails but rather provide a
  767. URL, you can upload to ftp://upload.mplayerhq.hu
  768. @item
  769. Did you provide a verbose summary about what the patch does change?
  770. @item
  771. Did you provide a verbose explanation why it changes things like it does?
  772. @item
  773. Did you provide a verbose summary of the user visible advantages and
  774. disadvantages if the patch is applied?
  775. @item
  776. Did you provide an example so we can verify the new feature added by the
  777. patch easily?
  778. @item
  779. If you added a new file, did you insert a license header? It should be
  780. taken from FFmpeg, not randomly copied and pasted from somewhere else.
  781. @item
  782. You should maintain alphabetical order in alphabetically ordered lists as
  783. long as doing so does not break API/ABI compatibility.
  784. @item
  785. Lines with similar content should be aligned vertically when doing so
  786. improves readability.
  787. @item
  788. Did you provide a suggestion for a clear commit log message?
  789. @end enumerate
  790. @section Patch review process
  791. All patches posted to ffmpeg-devel will be reviewed, unless they contain a
  792. clear note that the patch is not for SVN.
  793. Reviews and comments will be posted as replies to the patch on the
  794. mailing list. The patch submitter then has to take care of every comment,
  795. that can be by resubmitting a changed patch or by discussion. Resubmitted
  796. patches will themselves be reviewed like any other patch. If at some point
  797. a patch passes review with no comments then it is approved, that can for
  798. simple and small patches happen immediately while large patches will generally
  799. have to be changed and reviewed many times before they are approved.
  800. After a patch is approved it will be committed to the repository.
  801. We will review all submitted patches, but sometimes we are quite busy so
  802. especially for large patches this can take several weeks.
  803. When resubmitting patches, please do not make any significant changes
  804. not related to the comments received during review. Such patches will
  805. be rejected. Instead, submit significant changes or new features as
  806. separate patches.
  807. @section Regression tests
  808. Before submitting a patch (or committing to the repository), you should at least
  809. test that you did not break anything.
  810. The regression tests build a synthetic video stream and a synthetic
  811. audio stream. These are then encoded and decoded with all codecs or
  812. formats. The CRC (or MD5) of each generated file is recorded in a
  813. result file. A 'diff' is launched to compare the reference results and
  814. the result file.
  815. The regression tests then go on to test the FFserver code with a
  816. limited set of streams. It is important that this step runs correctly
  817. as well.
  818. Run 'make test' to test all the codecs and formats.
  819. Run 'make fulltest' to test all the codecs, formats and FFserver.
  820. [Of course, some patches may change the results of the regression tests. In
  821. this case, the reference results of the regression tests shall be modified
  822. accordingly].
  823. @bye