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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, wideband and narrowband. FFmpeg can make
  14. use of the AMR wideband (floating-point mode) and the AMR narrowband
  15. (floating-point mode) reference 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. Note that libamr is copyrighted without any sort of license grant. This means
  20. that you can use it if you legally obtained it but you are not allowed to
  21. redistribute it in any way. @strong{Any FFmpeg binaries with libamr support
  22. you create are non-free and unredistributable!}
  23. @chapter Supported File Formats and Codecs
  24. You can use the @code{-formats} option to have an exhaustive list.
  25. @section File Formats
  26. FFmpeg supports the following file formats through the @code{libavformat}
  27. library:
  28. @multitable @columnfractions .4 .1 .1 .4
  29. @item Supported File Format @tab Encoding @tab Decoding @tab Comments
  30. @item MPEG audio @tab X @tab X
  31. @item MPEG-1 systems @tab X @tab X
  32. @tab muxed audio and video
  33. @item MPEG-2 PS @tab X @tab X
  34. @tab also known as @code{VOB} file
  35. @item MPEG-2 TS @tab @tab X
  36. @tab also known as DVB Transport Stream
  37. @item ASF@tab X @tab X
  38. @item AVI@tab X @tab X
  39. @item WAV@tab X @tab X
  40. @item Macromedia Flash@tab X @tab X
  41. @tab Only embedded audio is decoded.
  42. @item FLV @tab X @tab X
  43. @tab Macromedia Flash video files
  44. @item Real Audio and Video @tab X @tab X
  45. @item Raw AC3 @tab X @tab X
  46. @item Raw MJPEG @tab X @tab X
  47. @item Raw MPEG video @tab X @tab X
  48. @item Raw PCM8/16 bits, mulaw/Alaw@tab X @tab X
  49. @item Raw CRI ADX audio @tab X @tab X
  50. @item Raw Shorten audio @tab @tab X
  51. @item SUN AU format @tab X @tab X
  52. @item NUT @tab X @tab X @tab NUT Open Container Format
  53. @item QuickTime @tab X @tab X
  54. @item MPEG-4 @tab X @tab X
  55. @tab MPEG-4 is a variant of QuickTime.
  56. @item Raw MPEG4 video @tab X @tab X
  57. @item DV @tab X @tab X
  58. @item 4xm @tab @tab X
  59. @tab 4X Technologies format, used in some games.
  60. @item Playstation STR @tab @tab X
  61. @item Id RoQ @tab X @tab X
  62. @tab Used in Quake III, Jedi Knight 2, other computer games.
  63. @item Interplay MVE @tab @tab X
  64. @tab Format used in various Interplay computer games.
  65. @item WC3 Movie @tab @tab X
  66. @tab Multimedia format used in Origin's Wing Commander III computer game.
  67. @item Sega FILM/CPK @tab @tab X
  68. @tab Used in many Sega Saturn console games.
  69. @item Westwood Studios VQA/AUD @tab @tab X
  70. @tab Multimedia formats used in Westwood Studios games.
  71. @item Id Cinematic (.cin) @tab @tab X
  72. @tab Used in Quake II.
  73. @item FLIC format @tab @tab X
  74. @tab .fli/.flc files
  75. @item Sierra VMD @tab @tab X
  76. @tab Used in Sierra CD-ROM games.
  77. @item Sierra Online @tab @tab X
  78. @tab .sol files used in Sierra Online games.
  79. @item Matroska @tab X @tab X
  80. @item Electronic Arts Multimedia @tab @tab X
  81. @tab Used in various EA games; files have extensions like WVE and UV2.
  82. @item Nullsoft Video (NSV) format @tab @tab X
  83. @item ADTS AAC audio @tab X @tab X
  84. @item Creative VOC @tab X @tab X @tab Created for the Sound Blaster Pro.
  85. @item American Laser Games MM @tab @tab X
  86. @tab Multimedia format used in games like Mad Dog McCree
  87. @item AVS @tab @tab X
  88. @tab Multimedia format used by the Creature Shock game.
  89. @item Smacker @tab @tab X
  90. @tab Multimedia format used by many games.
  91. @item GXF @tab X @tab X
  92. @tab General eXchange Format SMPTE 360M, used by Thomson Grass Valley playout servers.
  93. @item CIN @tab @tab X
  94. @tab Multimedia format used by Delphine Software games.
  95. @item MXF @tab @tab X
  96. @tab Material eXchange Format SMPTE 377M, used by D-Cinema, broadcast industry.
  97. @item SEQ @tab @tab X
  98. @tab Tiertex .seq files used in the DOS CDROM version of the game Flashback.
  99. @item DXA @tab @tab X
  100. @tab This format is used in non-Windows version of Feeble Files game and
  101. different game cutscenes repacked for use with ScummVM.
  102. @item THP @tab @tab X
  103. @tab Used on the Nintendo GameCube.
  104. @item C93 @tab @tab X
  105. @tab Used in the game Cyberia from Interplay.
  106. @item Bethsoft VID @tab @tab X
  107. @tab Used in some games from Bethesda Softworks.
  108. @item CRYO APC @tab @tab X
  109. @tab Audio format used in some games by CRYO Interactive Entertainment.
  110. @item Monkey's Audio @tab @tab X
  111. @item SIFF @tab @tab X
  112. @tab Audio and video format used in some games by Beam Software
  113. @end multitable
  114. @code{X} means that encoding (resp. decoding) is supported.
  115. @section Image Formats
  116. FFmpeg can read and write images for each frame of a video sequence. The
  117. following image formats are supported:
  118. @multitable @columnfractions .4 .1 .1 .4
  119. @item Supported Image Format @tab Encoding @tab Decoding @tab Comments
  120. @item PGM, PPM @tab X @tab X
  121. @item PAM @tab X @tab X @tab PAM is a PNM extension with alpha support.
  122. @item PGMYUV @tab X @tab X @tab PGM with U and V components in YUV 4:2:0
  123. @item JPEG @tab X @tab X @tab Progressive JPEG is not supported.
  124. @item .Y.U.V @tab X @tab X @tab one raw file per component
  125. @item animated GIF @tab X @tab X @tab Only uncompressed GIFs are generated.
  126. @item PNG @tab X @tab X @tab 2 bit and 4 bit/pixel not supported yet.
  127. @item Targa @tab @tab X @tab Targa (.TGA) image format.
  128. @item TIFF @tab X @tab X @tab YUV, JPEG and some extension is not supported yet.
  129. @item SGI @tab X @tab X @tab SGI RGB image format
  130. @item PTX @tab @tab X @tab V.Flash PTX format
  131. @end multitable
  132. @code{X} means that encoding (resp. decoding) is supported.
  133. @section Video Codecs
  134. @multitable @columnfractions .4 .1 .1 .4
  135. @item Supported Codec @tab Encoding @tab Decoding @tab Comments
  136. @item MPEG-1 video @tab X @tab X
  137. @item MPEG-2 video @tab X @tab X
  138. @item MPEG-4 @tab X @tab X
  139. @item MSMPEG4 V1 @tab X @tab X
  140. @item MSMPEG4 V2 @tab X @tab X
  141. @item MSMPEG4 V3 @tab X @tab X
  142. @item WMV7 @tab X @tab X
  143. @item WMV8 @tab X @tab X @tab not completely working
  144. @item WMV9 @tab @tab X @tab not completely working
  145. @item VC1 @tab @tab X
  146. @item H.261 @tab X @tab X
  147. @item H.263(+) @tab X @tab X @tab also known as RealVideo 1.0
  148. @item H.264 @tab @tab X
  149. @item RealVideo 1.0 @tab X @tab X
  150. @item RealVideo 2.0 @tab X @tab X
  151. @item MJPEG @tab X @tab X
  152. @item lossless MJPEG @tab X @tab X
  153. @item JPEG-LS @tab X @tab X @tab fourcc: MJLS, lossless and near-lossless is supported
  154. @item Apple MJPEG-B @tab @tab X
  155. @item Sunplus MJPEG @tab @tab X @tab fourcc: SP5X
  156. @item DV @tab X @tab X
  157. @item HuffYUV @tab X @tab X
  158. @item FFmpeg Video 1 @tab X @tab X @tab experimental lossless codec (fourcc: FFV1)
  159. @item FFmpeg Snow @tab X @tab X @tab experimental wavelet codec (fourcc: SNOW)
  160. @item Asus v1 @tab X @tab X @tab fourcc: ASV1
  161. @item Asus v2 @tab X @tab X @tab fourcc: ASV2
  162. @item Creative YUV @tab @tab X @tab fourcc: CYUV
  163. @item Sorenson Video 1 @tab X @tab X @tab fourcc: SVQ1
  164. @item Sorenson Video 3 @tab @tab X @tab fourcc: SVQ3
  165. @item On2 VP3 @tab @tab X @tab still experimental
  166. @item On2 VP5 @tab @tab X @tab fourcc: VP50
  167. @item On2 VP6 @tab @tab X @tab fourcc: VP60,VP61,VP62
  168. @item Theora @tab X @tab X @tab still experimental
  169. @item Intel Indeo 3 @tab @tab X
  170. @item FLV @tab X @tab X @tab Sorenson H.263 used in Flash
  171. @item Flash Screen Video @tab X @tab X @tab fourcc: FSV1
  172. @item ATI VCR1 @tab @tab X @tab fourcc: VCR1
  173. @item ATI VCR2 @tab @tab X @tab fourcc: VCR2
  174. @item Cirrus Logic AccuPak @tab @tab X @tab fourcc: CLJR
  175. @item 4X Video @tab @tab X @tab Used in certain computer games.
  176. @item Sony Playstation MDEC @tab @tab X
  177. @item Id RoQ @tab X @tab X @tab Used in Quake III, Jedi Knight 2, other computer games.
  178. @item Xan/WC3 @tab @tab X @tab Used in Wing Commander III .MVE files.
  179. @item Interplay Video @tab @tab X @tab Used in Interplay .MVE files.
  180. @item Apple Animation @tab X @tab X @tab fourcc: 'rle '
  181. @item Apple Graphics @tab @tab X @tab fourcc: 'smc '
  182. @item Apple Video @tab @tab X @tab fourcc: rpza
  183. @item Apple QuickDraw @tab @tab X @tab fourcc: qdrw
  184. @item Cinepak @tab @tab X
  185. @item Microsoft RLE @tab @tab X
  186. @item Microsoft Video-1 @tab @tab X
  187. @item Westwood VQA @tab @tab X
  188. @item Id Cinematic Video @tab @tab X @tab Used in Quake II.
  189. @item Planar RGB @tab @tab X @tab fourcc: 8BPS
  190. @item FLIC video @tab @tab X
  191. @item Duck TrueMotion v1 @tab @tab X @tab fourcc: DUCK
  192. @item Duck TrueMotion v2 @tab @tab X @tab fourcc: TM20
  193. @item VMD Video @tab @tab X @tab Used in Sierra VMD files.
  194. @item MSZH @tab @tab X @tab Part of LCL
  195. @item ZLIB @tab X @tab X @tab Part of LCL, encoder experimental
  196. @item TechSmith Camtasia @tab @tab X @tab fourcc: TSCC
  197. @item IBM Ultimotion @tab @tab X @tab fourcc: ULTI
  198. @item Miro VideoXL @tab @tab X @tab fourcc: VIXL
  199. @item QPEG @tab @tab X @tab fourccs: QPEG, Q1.0, Q1.1
  200. @item LOCO @tab @tab X @tab
  201. @item Winnov WNV1 @tab @tab X @tab
  202. @item Autodesk Animator Studio Codec @tab @tab X @tab fourcc: AASC
  203. @item Fraps FPS1 @tab @tab X @tab
  204. @item CamStudio @tab @tab X @tab fourcc: CSCD
  205. @item American Laser Games Video @tab @tab X @tab Used in games like Mad Dog McCree
  206. @item ZMBV @tab X @tab X @tab Encoder works only on PAL8
  207. @item AVS Video @tab @tab X @tab Video encoding used by the Creature Shock game.
  208. @item Smacker Video @tab @tab X @tab Video encoding used in Smacker.
  209. @item RTjpeg @tab @tab X @tab Video encoding used in NuppelVideo files.
  210. @item KMVC @tab @tab X @tab Codec used in Worms games.
  211. @item VMware Video @tab @tab X @tab Codec used in videos captured by VMware.
  212. @item Cin Video @tab @tab X @tab Codec used in Delphine Software games.
  213. @item Tiertex Seq Video @tab @tab X @tab Codec used in DOS CDROM FlashBack game.
  214. @item DXA Video @tab @tab X @tab Codec originally used in Feeble Files game.
  215. @item AVID DNxHD @tab X @tab X @tab aka SMPTE VC3
  216. @item C93 Video @tab @tab X @tab Codec used in Cyberia game.
  217. @item THP @tab @tab X @tab Used on the Nintendo GameCube.
  218. @item Bethsoft VID @tab @tab X @tab Used in some games from Bethesda Softworks.
  219. @item Renderware TXD @tab @tab X @tab Texture dictionaries used by the Renderware Engine.
  220. @item AMV @tab @tab X @tab Used in Chinese MP3 players.
  221. @end multitable
  222. @code{X} means that encoding (resp. decoding) is supported.
  223. @section Audio Codecs
  224. @multitable @columnfractions .4 .1 .1 .1 .7
  225. @item Supported Codec @tab Encoding @tab Decoding @tab Comments
  226. @item MPEG audio layer 2 @tab IX @tab IX
  227. @item MPEG audio layer 1/3 @tab X @tab IX
  228. @tab MP3 encoding is supported through the external library LAME.
  229. @item AC3 @tab IX @tab IX
  230. @tab liba52 is used internally for decoding.
  231. @item Vorbis @tab X @tab X
  232. @item WMA V1/V2 @tab X @tab X
  233. @item AAC @tab X @tab X
  234. @tab Supported through the external library libfaac/libfaad.
  235. @item Microsoft ADPCM @tab X @tab X
  236. @item AMV IMA ADPCM @tab @tab X
  237. @tab Used in AMV files
  238. @item MS IMA ADPCM @tab X @tab X
  239. @item QT IMA ADPCM @tab @tab X
  240. @item 4X IMA ADPCM @tab @tab X
  241. @item G.726 ADPCM @tab X @tab X
  242. @item Duck DK3 IMA ADPCM @tab @tab X
  243. @tab Used in some Sega Saturn console games.
  244. @item Duck DK4 IMA ADPCM @tab @tab X
  245. @tab Used in some Sega Saturn console games.
  246. @item Westwood Studios IMA ADPCM @tab @tab X
  247. @tab Used in Westwood Studios games like Command and Conquer.
  248. @item SMJPEG IMA ADPCM @tab @tab X
  249. @tab Used in certain Loki game ports.
  250. @item CD-ROM XA ADPCM @tab @tab X
  251. @item CRI ADX ADPCM @tab X @tab X
  252. @tab Used in Sega Dreamcast games.
  253. @item Electronic Arts ADPCM @tab @tab X
  254. @tab Used in various EA titles.
  255. @item Creative ADPCM @tab @tab X
  256. @tab 16 -> 4, 8 -> 4, 8 -> 3, 8 -> 2
  257. @item THP ADPCM @tab @tab X
  258. @tab Used on the Nintendo GameCube.
  259. @item RA144 @tab @tab X
  260. @tab Real 14400 bit/s codec
  261. @item RA288 @tab @tab X
  262. @tab Real 28800 bit/s codec
  263. @item RADnet @tab X @tab IX
  264. @tab Real low bitrate AC3 codec, liba52 is used for decoding.
  265. @item AMR-NB @tab X @tab X
  266. @tab Supported through an external library.
  267. @item AMR-WB @tab X @tab X
  268. @tab Supported through an external library.
  269. @item DV audio @tab @tab X
  270. @item Id RoQ DPCM @tab X @tab X
  271. @tab Used in Quake III, Jedi Knight 2, other computer games.
  272. @item Interplay MVE DPCM @tab @tab X
  273. @tab Used in various Interplay computer games.
  274. @item Xan DPCM @tab @tab X
  275. @tab Used in Origin's Wing Commander IV AVI files.
  276. @item Sierra Online DPCM @tab @tab X
  277. @tab Used in Sierra Online game audio files.
  278. @item Apple MACE 3 @tab @tab X
  279. @item Apple MACE 6 @tab @tab X
  280. @item FLAC lossless audio @tab X @tab X
  281. @item Shorten lossless audio @tab @tab X
  282. @item Apple lossless audio @tab @tab X
  283. @tab QuickTime fourcc 'alac'
  284. @item FFmpeg Sonic @tab X @tab X
  285. @tab experimental lossy/lossless codec
  286. @item Qdesign QDM2 @tab @tab X
  287. @tab there are still some distortions
  288. @item Real COOK @tab @tab X
  289. @tab All versions except 5.1 are supported
  290. @item DSP Group TrueSpeech @tab @tab X
  291. @item True Audio (TTA) @tab @tab X
  292. @item Smacker Audio @tab @tab X
  293. @item WavPack Audio @tab @tab X
  294. @item Cin Audio @tab @tab X
  295. @tab Codec used in Delphine Software games.
  296. @item Intel Music Coder @tab @tab X
  297. @item Musepack @tab @tab X
  298. @tab SV7 and SV8 are supported
  299. @item DT$ Coherent Audio @tab @tab X
  300. @item ATRAC 3 @tab @tab X
  301. @item Monkey's Audio @tab @tab X @tab Only versions 3.97-3.99 are supported
  302. @item Nellymoser ASAO @tab @tab X
  303. @end multitable
  304. @code{X} means that encoding (resp. decoding) is supported.
  305. @code{I} means that an integer-only version is available, too (ensures high
  306. performance on systems without hardware floating point support).
  307. @chapter Platform Specific information
  308. @section BSD
  309. BSD make will not build FFmpeg, you need to install and use GNU Make
  310. (@file{gmake}).
  311. @section Windows
  312. To get help and instructions for building FFmpeg under Windows, check out
  313. the FFmpeg Windows Help Forum at
  314. @url{http://arrozcru.no-ip.org/ffmpeg/}.
  315. @subsection Native Windows compilation
  316. FFmpeg can be built to run natively on Windows using the MinGW tools. Install
  317. the current versions of MSYS and MinGW from @url{http://www.mingw.org/}. Also
  318. install the coreutils package. You can find detailed installation
  319. instructions in the download section and the FAQ.
  320. Within the MSYS shell, configure and make with:
  321. @example
  322. ./configure --enable-memalign-hack
  323. make
  324. make install
  325. @end example
  326. This will install @file{ffmpeg.exe} along with many other development files
  327. to @file{/usr/local}. You may specify another install path using the
  328. @code{--prefix} option in @file{configure}.
  329. Notes:
  330. @itemize
  331. @item Use at least bash 3.1. Older versions are known to be fail on the
  332. configure script.
  333. @item In order to compile vhooks, you must have a POSIX-compliant libdl in
  334. your MinGW system. Get dlfcn-win32 from
  335. @url{http://code.google.com/p/dlfcn-win32}.
  336. @item In order to compile FFplay, you must have the MinGW development library
  337. of SDL. Get it from @url{http://www.libsdl.org}.
  338. Edit the @file{bin/sdl-config} script so that it points to the correct prefix
  339. where SDL was installed. Verify that @file{sdl-config} can be launched from
  340. the MSYS command line.
  341. @item The target @code{make wininstaller} can be used to create a
  342. Nullsoft-based Windows installer for FFmpeg and FFplay. @file{SDL.dll}
  343. must be copied to the FFmpeg directory in order to build the
  344. installer.
  345. @item By using @code{./configure --enable-shared} when configuring FFmpeg,
  346. you can build libavutil, libavcodec and libavformat as DLLs.
  347. @end itemize
  348. @subsection Microsoft Visual C++ compatibility
  349. As stated in the FAQ, FFmpeg will not compile under MSVC++. However, if you
  350. want to use the libav* libraries in your own applications, you can still
  351. compile those applications using MSVC++. But the libav* libraries you link
  352. to @emph{must} be built with MinGW. However, you will not be able to debug
  353. inside the libav* libraries, since MSVC++ does not recognize the debug
  354. symbols generated by GCC.
  355. We strongly recommend you to move over from MSVC++ to MinGW tools.
  356. This description of how to use the FFmpeg libraries with MSVC++ is based on
  357. Microsoft Visual C++ 2005 Express Edition. If you have a different version,
  358. you might have to modify the procedures slightly.
  359. @subsubsection Using static libraries
  360. Assuming you have just built and installed FFmpeg in @file{/usr/local}.
  361. @enumerate
  362. @item Create a new console application ("File / New / Project") and then
  363. select "Win32 Console Application". On the appropriate page of the
  364. Application Wizard, uncheck the "Precompiled headers" option.
  365. @item Write the source code for your application, or, for testing, just
  366. copy the code from an existing sample application into the source file
  367. that MSVC++ has already created for you. For example, you can copy
  368. @file{output_example.c} from the FFmpeg distribution.
  369. @item Open the "Project / Properties" dialog box. In the "Configuration"
  370. combo box, select "All Configurations" so that the changes you make will
  371. affect both debug and release builds. In the tree view on the left hand
  372. side, select "C/C++ / General", then edit the "Additional Include
  373. Directories" setting to contain the path where the FFmpeg includes were
  374. installed (i.e. @file{c:\msys\1.0\local\include}).
  375. @item Still in the "Project / Properties" dialog box, select
  376. "Linker / General" from the tree view and edit the
  377. "Additional Library Directories" setting to contain the @file{lib}
  378. directory where FFmpeg was installed (i.e. @file{c:\msys\1.0\local\lib}),
  379. the directory where MinGW libs are installed (i.e. @file{c:\mingw\lib}),
  380. and the directory where MinGW's GCC libs are installed
  381. (i.e. @file{C:\mingw\lib\gcc\mingw32\4.2.1-sjlj}). Then select
  382. "Linker / Input" from the tree view, and add the files @file{libavformat.a},
  383. @file{libavcodec.a}, @file{libavutil.a}, @file{libmingwex.a},
  384. @file{libgcc.a}, and any other libraries you used (i.e. @file{libz.a})
  385. to the end of "Additional Dependencies".
  386. @item Now, select "C/C++ / Code Generation" from the tree view. Select
  387. "Debug" in the "Configuration" combo box. Make sure that "Runtime
  388. Library" is set to "Multi-threaded Debug DLL". Then, select "Release" in
  389. the "Configuration" combo box and make sure that "Runtime Library" is
  390. set to "Multi-threaded DLL".
  391. @item Click "OK" to close the "Project / Properties" dialog box.
  392. @item MSVC++ lacks some C99 header files that are fundamental for FFmpeg.
  393. Get msinttypes from @url{http://code.google.com/p/msinttypes/downloads/list}
  394. and install it in MSVC++'s include directory
  395. (i.e. @file{C:\Program Files\Microsoft Visual Studio 8\VC\include}).
  396. @item MSVC++ also does not understand the @code{inline} keyword used by
  397. FFmpeg, so you must add this line before @code{#include}ing libav*:
  398. @example
  399. #define inline _inline
  400. @end example
  401. @item If you used @file{output_example.c} as your sample application,
  402. you will have to edit the @code{#include}s to point to the files which
  403. are under the @file{ffmpeg} directory (i.e. @code{<ffmpeg/avformat.h>}).
  404. @item Build your application, everything should work.
  405. @end enumerate
  406. @subsubsection Using shared libraries
  407. This is how to create DLL and LIB files that are compatible with MSVC++:
  408. @enumerate
  409. @item Add a call to @file{vcvars32.bat} (which sets up the environment
  410. variables for the Visual C++ tools) as the first line of @file{msys.bat}.
  411. The standard location for @file{vcvars32.bat} is
  412. @file{C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat},
  413. and the standard location for @file{msys.bat} is @file{C:\msys\1.0\msys.bat}.
  414. If this corresponds to your setup, add the following line as the first line
  415. of @file{msys.bat}:
  416. @example
  417. call "C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat"
  418. @end example
  419. Alternatively, you may start the @file{Visual Studio 2005 Command Prompt},
  420. and run @file{c:\msys\1.0\msys.bat} from there.
  421. @item Within the MSYS shell, run @code{lib.exe}. If you get a help message
  422. from @file{Microsoft (R) Library Manager}, this means your environment
  423. variables are set up correctly, the @file{Microsoft (R) Library Manager}
  424. is on the path and will be used by FFmpeg to create
  425. MSVC++-compatible import libraries.
  426. @item Build FFmpeg with
  427. @example
  428. ./configure --enable-shared --enable-memalign-hack
  429. make
  430. make install
  431. @end example
  432. Your install path (@file{/usr/local/} by default) should now have the
  433. necessary DLL and LIB files under the @file{bin} directory.
  434. @end enumerate
  435. To use those files with MSVC++, do the same as you would do with
  436. the static libraries, as described above. But in Step 4,
  437. you should only need to add the directory where the LIB files are installed
  438. (i.e. @file{c:\msys\usr\local\bin}). This is not a typo, the LIB files are
  439. installed in the @file{bin} directory. And instead of adding @file{libxx.a}
  440. files, you should add @file{avcodec.lib}, @file{avformat.lib}, and
  441. @file{avutil.lib}. There should be no need for @file{libmingwex.a},
  442. @file{libgcc.a}, and @file{wsock32.lib}, nor any other external library
  443. statically linked into the DLLs. The @file{bin} directory contains a bunch
  444. of DLL files, but the ones that are actually used to run your application
  445. are the ones with a major version number in their filenames
  446. (i.e. @file{avcodec-51.dll}).
  447. @subsection Cross compilation for Windows with Linux
  448. You must use the MinGW cross compilation tools available at
  449. @url{http://www.mingw.org/}.
  450. Then configure FFmpeg with the following options:
  451. @example
  452. ./configure --target-os=mingw32 --cross-prefix=i386-mingw32msvc-
  453. @end example
  454. (you can change the cross-prefix according to the prefix chosen for the
  455. MinGW tools).
  456. Then you can easily test FFmpeg with Wine
  457. (@url{http://www.winehq.com/}).
  458. @subsection Compilation under Cygwin
  459. The main issue with Cygwin is that newlib, its C library, does not
  460. contain llrint(). However, it is possible to leverage the
  461. implementation in MinGW.
  462. Just install your Cygwin with all the "Base" packages, plus the
  463. following "Devel" ones:
  464. @example
  465. binutils, gcc-core, make, subversion, mingw-runtime
  466. @end example
  467. Do not install binutils-20060709-1 (they are buggy on shared builds);
  468. use binutils-20050610-1 instead.
  469. Then create a small library that just contains llrint():
  470. @example
  471. ar x /usr/lib/mingw/libmingwex.a llrint.o
  472. ar cq /usr/local/lib/libllrint.a llrint.o
  473. @end example
  474. Then run
  475. @example
  476. ./configure --enable-static --disable-shared --extra-ldflags='-L /usr/local/lib' --extra-libs='-l llrint'
  477. @end example
  478. to make a static build or
  479. @example
  480. ./configure --enable-shared --disable-static --extra-ldflags='-L /usr/local/lib' --extra-libs='-l llrint'
  481. @end example
  482. to build shared libraries.
  483. If you want to build FFmpeg with additional libraries, download Cygwin
  484. "Devel" packages for Ogg and Vorbis from any Cygwin packages repository
  485. and/or SDL, xvid, faac, faad2 packages from Cygwin Ports,
  486. (@url{http://cygwinports.dotsrc.org/}).
  487. @subsection Crosscompilation for Windows under Cygwin
  488. With Cygwin you can create Windows binaries that do not need the cygwin1.dll.
  489. Just install your Cygwin as explained before, plus these additional
  490. "Devel" packages:
  491. @example
  492. gcc-mingw-core, mingw-runtime, mingw-zlib
  493. @end example
  494. and add some special flags to your configure invocation.
  495. For a static build run
  496. @example
  497. ./configure --target-os=mingw32 --enable-memalign-hack --enable-static --disable-shared --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
  498. @end example
  499. and for a build with shared libraries
  500. @example
  501. ./configure --target-os=mingw32 --enable-memalign-hack --enable-shared --disable-static --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
  502. @end example
  503. @section BeOS
  504. BeOS support is broken in mysterious ways.
  505. @section OS/2
  506. For information about compiling FFmpeg on OS/2 see
  507. @url{http://www.edm2.com/index.php/FFmpeg}.
  508. @chapter Developers Guide
  509. @section API
  510. @itemize @bullet
  511. @item libavcodec is the library containing the codecs (both encoding and
  512. decoding). Look at @file{libavcodec/apiexample.c} to see how to use it.
  513. @item libavformat is the library containing the file format handling (mux and
  514. demux code for several formats). Look at @file{ffplay.c} to use it in a
  515. player. See @file{output_example.c} to use it to generate audio or video
  516. streams.
  517. @end itemize
  518. @section Integrating libavcodec or libavformat in your program
  519. You can integrate all the source code of the libraries to link them
  520. statically to avoid any version problem. All you need is to provide a
  521. 'config.mak' and a 'config.h' in the parent directory. See the defines
  522. generated by ./configure to understand what is needed.
  523. You can use libavcodec or libavformat in your commercial program, but
  524. @emph{any patch you make must be published}. The best way to proceed is
  525. to send your patches to the FFmpeg mailing list.
  526. @node Coding Rules
  527. @section Coding Rules
  528. FFmpeg is programmed in the ISO C90 language with a few additional
  529. features from ISO C99, namely:
  530. @itemize @bullet
  531. @item
  532. the @samp{inline} keyword;
  533. @item
  534. @samp{//} comments;
  535. @item
  536. designated struct initializers (@samp{struct s x = @{ .i = 17 @};})
  537. @item
  538. compound literals (@samp{x = (struct s) @{ 17, 23 @};})
  539. @end itemize
  540. These features are supported by all compilers we care about, so we will not
  541. accept patches to remove their use unless they absolutely do not impair
  542. clarity and performance.
  543. All code must compile with GCC 2.95 and GCC 3.3. Currently, FFmpeg also
  544. compiles with several other compilers, such as the Compaq ccc compiler
  545. or Sun Studio 9, and we would like to keep it that way unless it would
  546. be exceedingly involved. To ensure compatibility, please do not use any
  547. additional C99 features or GCC extensions. Especially watch out for:
  548. @itemize @bullet
  549. @item
  550. mixing statements and declarations;
  551. @item
  552. @samp{long long} (use @samp{int64_t} instead);
  553. @item
  554. @samp{__attribute__} not protected by @samp{#ifdef __GNUC__} or similar;
  555. @item
  556. GCC statement expressions (@samp{(x = (@{ int y = 4; y; @})}).
  557. @end itemize
  558. Indent size is 4.
  559. The presentation is the one specified by 'indent -i4 -kr -nut'.
  560. The TAB character is forbidden outside of Makefiles as is any
  561. form of trailing whitespace. Commits containing either will be
  562. rejected by the Subversion repository.
  563. The main priority in FFmpeg is simplicity and small code size in order to
  564. minimize the bug count.
  565. Comments: Use the JavaDoc/Doxygen
  566. format (see examples below) so that code documentation
  567. can be generated automatically. All nontrivial functions should have a comment
  568. above them explaining what the function does, even if it is just one sentence.
  569. All structures and their member variables should be documented, too.
  570. @example
  571. /**
  572. * @@file mpeg.c
  573. * MPEG codec.
  574. * @@author ...
  575. */
  576. /**
  577. * Summary sentence.
  578. * more text ...
  579. * ...
  580. */
  581. typedef struct Foobar@{
  582. int var1; /**< var1 description */
  583. int var2; ///< var2 description
  584. /** var3 description */
  585. int var3;
  586. @} Foobar;
  587. /**
  588. * Summary sentence.
  589. * more text ...
  590. * ...
  591. * @@param my_parameter description of my_parameter
  592. * @@return return value description
  593. */
  594. int myfunc(int my_parameter)
  595. ...
  596. @end example
  597. fprintf and printf are forbidden in libavformat and libavcodec,
  598. please use av_log() instead.
  599. Casts should be used only when necessary. Unneeded parentheses
  600. should also be avoided if they don't make the code easier to understand.
  601. @section Development Policy
  602. @enumerate
  603. @item
  604. Contributions should be licensed under the LGPL 2.1, including an
  605. "or any later version" clause, or the MIT license. GPL 2 including
  606. an "or any later version" clause is also acceptable, but LGPL is
  607. preferred.
  608. @item
  609. You must not commit code which breaks FFmpeg! (Meaning unfinished but
  610. enabled code which breaks compilation or compiles but does not work or
  611. breaks the regression tests)
  612. You can commit unfinished stuff (for testing etc), but it must be disabled
  613. (#ifdef etc) by default so it does not interfere with other developers'
  614. work.
  615. @item
  616. You do not have to over-test things. If it works for you, and you think it
  617. should work for others, then commit. If your code has problems
  618. (portability, triggers compiler bugs, unusual environment etc) they will be
  619. reported and eventually fixed.
  620. @item
  621. Do not commit unrelated changes together, split them into self-contained
  622. pieces. Also do not forget that if part B depends on part A, but A does not
  623. depend on B, then A can and should be committed first and separate from B.
  624. Keeping changes well split into self-contained parts makes reviewing and
  625. understanding them on the commit log mailing list easier. This also helps
  626. in case of debugging later on.
  627. Also if you have doubts about splitting or not splitting, do not hesitate to
  628. ask/discuss it on the developer mailing list.
  629. @item
  630. Do not change behavior of the program (renaming options etc) without
  631. first discussing it on the ffmpeg-devel mailing list. Do not remove
  632. functionality from the code. Just improve!
  633. Note: Redundant code can be removed.
  634. @item
  635. Do not commit changes to the build system (Makefiles, configure script)
  636. which change behavior, defaults etc, without asking first. The same
  637. applies to compiler warning fixes, trivial looking fixes and to code
  638. maintained by other developers. We usually have a reason for doing things
  639. the way we do. Send your changes as patches to the ffmpeg-devel mailing
  640. list, and if the code maintainers say OK, you may commit. This does not
  641. apply to files you wrote and/or maintain.
  642. @item
  643. We refuse source indentation and other cosmetic changes if they are mixed
  644. with functional changes, such commits will be rejected and removed. Every
  645. developer has his own indentation style, you should not change it. Of course
  646. if you (re)write something, you can use your own style, even though we would
  647. prefer if the indentation throughout FFmpeg was consistent (Many projects
  648. force a given indentation style - we do not.). If you really need to make
  649. indentation changes (try to avoid this), separate them strictly from real
  650. changes.
  651. NOTE: If you had to put if()@{ .. @} over a large (> 5 lines) chunk of code,
  652. then either do NOT change the indentation of the inner part within (do not
  653. move it to the right)! or do so in a separate commit
  654. @item
  655. Always fill out the commit log message. Describe in a few lines what you
  656. changed and why. You can refer to mailing list postings if you fix a
  657. particular bug. Comments such as "fixed!" or "Changed it." are unacceptable.
  658. @item
  659. If you apply a patch by someone else, include the name and email address in
  660. the log message. Since the ffmpeg-cvslog mailing list is publicly
  661. archived you should add some SPAM protection to the email address. Send an
  662. answer to ffmpeg-devel (or wherever you got the patch from) saying that
  663. you applied the patch.
  664. @item
  665. When applying patches that have been discussed (at length) on the mailing
  666. list, reference the thread in the log message.
  667. @item
  668. Do NOT commit to code actively maintained by others without permission.
  669. Send a patch to ffmpeg-devel instead. If no one answers within a reasonable
  670. timeframe (12h for build failures and security fixes, 3 days small changes,
  671. 1 week for big patches) then commit your patch if you think it is OK.
  672. Also note, the maintainer can simply ask for more time to review!
  673. @item
  674. Subscribe to the ffmpeg-cvslog mailing list. The diffs of all commits
  675. are sent there and reviewed by all the other developers. Bugs and possible
  676. improvements or general questions regarding commits are discussed there. We
  677. expect you to react if problems with your code are uncovered.
  678. @item
  679. Update the documentation if you change behavior or add features. If you are
  680. unsure how best to do this, send a patch to ffmpeg-devel, the documentation
  681. maintainer(s) will review and commit your stuff.
  682. @item
  683. Try to keep important discussions and requests (also) on the public
  684. developer mailing list, so that all developers can benefit from them.
  685. @item
  686. Never write to unallocated memory, never write over the end of arrays,
  687. always check values read from some untrusted source before using them
  688. as array index or other risky things.
  689. @item
  690. Remember to check if you need to bump versions for the specific libav
  691. parts (libavutil, libavcodec, libavformat) you are changing. You need
  692. to change the version integer and the version string.
  693. Incrementing the first component means no backward compatibility to
  694. previous versions (e.g. removal of a function from the public API).
  695. Incrementing the second component means backward compatible change
  696. (e.g. addition of a function to the public API).
  697. Incrementing the third component means a noteworthy binary compatible
  698. change (e.g. encoder bug fix that matters for the decoder).
  699. @item
  700. If you add a new codec, remember to update the changelog, add it to
  701. the supported codecs table in the documentation and bump the second
  702. component of the @file{libavcodec} version number appropriately. If
  703. it has a fourcc, add it to @file{libavformat/avienc.c}, even if it
  704. is only a decoder.
  705. @item
  706. Do not change code to hide warnings without ensuring that the underlying
  707. logic is correct and thus the warning was inappropriate.
  708. @item
  709. If you add a new file, give it a proper license header. Do not copy and
  710. paste it from a random place, use an existing file as template.
  711. @end enumerate
  712. We think our rules are not too hard. If you have comments, contact us.
  713. Note, these rules are mostly borrowed from the MPlayer project.
  714. @section Submitting patches
  715. First, (@pxref{Coding Rules}) above if you did not yet.
  716. When you submit your patch, try to send a unified diff (diff '-up'
  717. option). We cannot read other diffs :-)
  718. Also please do not submit a patch which contains several unrelated changes.
  719. Split it into separate, self-contained pieces. This does not mean splitting
  720. file by file. Instead, make the patch as small as possible while still
  721. keeping it as a logical unit that contains an individual change, even
  722. if it spans multiple files. This makes reviewing your patches much easier
  723. for us and greatly increases your chances of getting your patch applied.
  724. Run the regression tests before submitting a patch so that you can
  725. verify that there are no big problems.
  726. Patches should be posted as base64 encoded attachments (or any other
  727. encoding which ensures that the patch will not be trashed during
  728. transmission) to the ffmpeg-devel mailing list, see
  729. @url{http://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel}
  730. It also helps quite a bit if you tell us what the patch does (for example
  731. 'replaces lrint by lrintf'), and why (for example '*BSD isn't C99 compliant
  732. and has no lrint()')
  733. Also please if you send several patches, send each patch as a separate mail,
  734. do not attach several unrelated patches to the same mail.
  735. @section patch submission checklist
  736. @enumerate
  737. @item
  738. Do the regression tests pass with the patch applied?
  739. @item
  740. Is the patch a unified diff?
  741. @item
  742. Is the patch against latest FFmpeg SVN?
  743. @item
  744. Are you subscribed to ffmpeg-dev?
  745. (the list is subscribers only due to spam)
  746. @item
  747. Have you checked that the changes are minimal, so that the same cannot be
  748. achieved with a smaller patch and/or simpler final code?
  749. @item
  750. If the change is to speed critical code, did you benchmark it?
  751. @item
  752. If you did any benchmarks, did you provide them in the mail?
  753. @item
  754. Have you checked that the patch does not introduce buffer overflows or
  755. other security issues?
  756. @item
  757. Is the patch created from the root of the source tree, so it can be
  758. applied with @code{patch -p0}?
  759. @item
  760. Does the patch not mix functional and cosmetic changes?
  761. @item
  762. Did you add tabs or trailing whitespace to the code? Both are forbidden.
  763. @item
  764. Is the patch attached to the email you send?
  765. @item
  766. Is the mime type of the patch correct? It should be text/x-diff or
  767. text/x-patch or at least text/plain and not application/octet-stream.
  768. @item
  769. If the patch fixes a bug, did you provide a verbose analysis of the bug?
  770. @item
  771. If the patch fixes a bug, did you provide enough information, including
  772. a sample, so the bug can be reproduced and the fix can be verified?
  773. Note please do not attach samples >100k to mails but rather provide a
  774. URL, you can upload to ftp://upload.mplayerhq.hu
  775. @item
  776. Did you provide a verbose summary about what the patch does change?
  777. @item
  778. Did you provide a verbose explanation why it changes things like it does?
  779. @item
  780. Did you provide a verbose summary of the user visible advantages and
  781. disadvantages if the patch is applied?
  782. @item
  783. Did you provide an example so we can verify the new feature added by the
  784. patch easily?
  785. @item
  786. If you added a new file, did you insert a license header? It should be
  787. taken from FFmpeg, not randomly copied and pasted from somewhere else.
  788. @item
  789. You should maintain alphabetical order in alphabetically ordered lists as
  790. long as doing so does not break API/ABI compatibility.
  791. @item
  792. Lines with similar content should be aligned vertically when doing so
  793. improves readability.
  794. @item
  795. Did you provide a suggestion for a clear commit log message?
  796. @item
  797. Did you test your decoder or demuxer against damaged data? If no, see
  798. tools/trasher and the noise bitstream filter. Your decoder or demuxer
  799. should not crash or end in a (near) infinite loop when feeded with
  800. damaged data.
  801. @end enumerate
  802. @section Patch review process
  803. All patches posted to ffmpeg-devel will be reviewed, unless they contain a
  804. clear note that the patch is not for SVN.
  805. Reviews and comments will be posted as replies to the patch on the
  806. mailing list. The patch submitter then has to take care of every comment,
  807. that can be by resubmitting a changed patch or by discussion. Resubmitted
  808. patches will themselves be reviewed like any other patch. If at some point
  809. a patch passes review with no comments then it is approved, that can for
  810. simple and small patches happen immediately while large patches will generally
  811. have to be changed and reviewed many times before they are approved.
  812. After a patch is approved it will be committed to the repository.
  813. We will review all submitted patches, but sometimes we are quite busy so
  814. especially for large patches this can take several weeks.
  815. When resubmitting patches, please do not make any significant changes
  816. not related to the comments received during review. Such patches will
  817. be rejected. Instead, submit significant changes or new features as
  818. separate patches.
  819. @section Regression tests
  820. Before submitting a patch (or committing to the repository), you should at least
  821. test that you did not break anything.
  822. The regression tests build a synthetic video stream and a synthetic
  823. audio stream. These are then encoded and decoded with all codecs or
  824. formats. The CRC (or MD5) of each generated file is recorded in a
  825. result file. A 'diff' is launched to compare the reference results and
  826. the result file.
  827. The regression tests then go on to test the FFserver code with a
  828. limited set of streams. It is important that this step runs correctly
  829. as well.
  830. Run 'make test' to test all the codecs and formats.
  831. Run 'make fulltest' to test all the codecs, formats and FFserver.
  832. [Of course, some patches may change the results of the regression tests. In
  833. this case, the reference results of the regression tests shall be modified
  834. accordingly].
  835. @bye