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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 Name @tab Encoding @tab Decoding @tab Comments
  30. @item 4xm @tab @tab X
  31. @tab 4X Technologies format, used in some games.
  32. @item 8088flex TMV @tab @tab X
  33. @item Audio IFF (AIFF) @tab X @tab X
  34. @item American Laser Games MM @tab @tab X
  35. @tab Multimedia format used in games like Mad Dog McCree.
  36. @item 3GPP AMR @tab X @tab X
  37. @item ASF @tab X @tab X
  38. @item AVI @tab X @tab X
  39. @item AVISynth @tab @tab X
  40. @item AVS @tab @tab X
  41. @tab Multimedia format used by the Creature Shock game.
  42. @item Beam Software SIFF @tab @tab X
  43. @tab Audio and video format used in some games by Beam Software.
  44. @item Bethesda Softworks VID @tab @tab X
  45. @tab Used in some games from Bethesda Softworks.
  46. @item Brute Force & Ignorance @tab @tab X
  47. @tab Used in the game Flash Traffic: City of Angels.
  48. @item Interplay C93 @tab @tab X
  49. @tab Used in the game Cyberia from Interplay.
  50. @item Delphine Software International CIN @tab @tab X
  51. @tab Multimedia format used by Delphine Software games.
  52. @item CRC testing format @tab X @tab
  53. @item Creative Voice @tab X @tab X
  54. @tab Created for the Sound Blaster Pro.
  55. @item CRYO APC @tab @tab X
  56. @tab Audio format used in some games by CRYO Interactive Entertainment.
  57. @item D-Cinema audio @tab X @tab X
  58. @item DV video @tab X @tab X
  59. @item DXA @tab @tab X
  60. @tab This format is used in the non-Windows version of the Feeble Files
  61. game and different game cutscenes repacked for use with ScummVM.
  62. @item Electronic Arts cdata @tab @tab X
  63. @item Electronic Arts Multimedia @tab @tab X
  64. @tab Used in various EA games; files have extensions like WVE and UV2.
  65. @item FFM (FFserver live feed) @tab X @tab X
  66. @item Flash (SWF) @tab X @tab X
  67. @item Flash 9 (AVM2) @tab X @tab X
  68. @tab Only embedded audio is decoded.
  69. @item FLI/FLC/FLX animation @tab @tab X
  70. @tab .fli/.flc files
  71. @item Flash Video (FLV) @tab @tab X
  72. @tab Macromedia Flash video files
  73. @item framecrc testing format @tab X @tab
  74. @item FunCom ISS @tab @tab X
  75. @tab Audio format used in various games from FunCom like The Longest Journey.
  76. @item GIF Animation @tab X @tab
  77. @item GXF @tab X @tab X
  78. @tab General eXchange Format SMPTE 360M, used by Thomson Grass Valley
  79. playout servers.
  80. @item id Quake II CIN video @tab @tab X
  81. @item id RoQ @tab X @tab X
  82. @tab Used in Quake III, Jedi Knight 2, other computer games.
  83. @item IFF @tab @tab X
  84. @tab Interchange File Format
  85. @item Interplay MVE @tab @tab X
  86. @tab Format used in various Interplay computer games.
  87. @item LMLM4 @tab @tab X
  88. @tab Used by Linux Media Labs MPEG-4 PCI boards
  89. @item Matroska @tab X @tab X
  90. @item Matroska audio @tab X @tab
  91. @item MAXIS XA @tab @tab X
  92. @tab Used in Sim City 3000; file extension .xa.
  93. @item Monkey's Audio @tab @tab X
  94. @item Motion Pixels MVI @tab @tab X
  95. @item MOV/QuickTime/MP4 @tab X @tab X
  96. @tab 3GP, 3GP2, PSP, iPod variants supported
  97. @item MP2 @tab X @tab X
  98. @item MP3 @tab X @tab X
  99. @item MPEG-1 System @tab X @tab X
  100. @tab muxed audio and video, VCD format supported
  101. @item MPEG-PS (program stream) @tab X @tab X
  102. @tab also known as @code{VOB} file, SVCD and DVD format supported
  103. @item MPEG-TS (transport stream) @tab X @tab X
  104. @tab also known as DVB Transport Stream
  105. @item MPEG-4 @tab X @tab X
  106. @tab MPEG-4 is a variant of QuickTime.
  107. @item MIME multipart JPEG @tab X @tab
  108. @item MSN TCP webcam @tab @tab X
  109. @tab Used by MSN Messenger webcam streams.
  110. @item MTV @tab @tab X
  111. @item Musepack @tab @tab X
  112. @item Musepack SV8 @tab @tab X
  113. @item Material eXchange Format (MXF) @tab X @tab X
  114. @tab SMPTE 377M, used by D-Cinema, broadcast industry.
  115. @item Material eXchange Format (MXF), D-10 Mapping @tab X @tab X
  116. @tab SMPTE 386M, D-10/IMX Mapping.
  117. @item NC camera feed @tab @tab X
  118. @tab NC (AVIP NC4600) camera streams
  119. @item NTT TwinVQ (VQF) @tab @tab X
  120. @tab Nippon Telegraph and Telephone Corporation TwinVQ.
  121. @item Nullsoft Streaming Video @tab @tab X
  122. @item NuppelVideo @tab @tab X
  123. @item NUT @tab X @tab X
  124. @tab NUT Open Container Format
  125. @item Ogg @tab X @tab X
  126. @item TechnoTrend PVA @tab @tab X
  127. @tab Used by TechnoTrend DVB PCI boards.
  128. @item QCP @tab @tab X
  129. @item raw ADTS (AAC) @tab X @tab X
  130. @item raw AC-3 @tab X @tab X
  131. @item raw Chinese AVS video @tab @tab X
  132. @item raw CRI ADX @tab X @tab X
  133. @item raw Dirac @tab X @tab X
  134. @item raw DNxHD @tab X @tab X
  135. @item raw DTS @tab X @tab X
  136. @item raw E-AC-3 @tab X @tab X
  137. @item raw FLAC @tab X @tab X
  138. @item raw GSM @tab @tab X
  139. @item raw H.261 @tab X @tab X
  140. @item raw H.263 @tab X @tab X
  141. @item raw H.264 @tab X @tab X
  142. @item raw Ingenient MJPEG @tab @tab X
  143. @item raw MJPEG @tab X @tab X
  144. @item raw MLP @tab @tab X
  145. @item raw MPEG @tab @tab X
  146. @item raw MPEG-1 @tab @tab X
  147. @item raw MPEG-2 @tab @tab X
  148. @item raw MPEG-4 @tab X @tab X
  149. @item raw NULL @tab X @tab
  150. @item raw video @tab X @tab X
  151. @item raw id RoQ @tab X @tab
  152. @item raw Shorten @tab @tab X
  153. @item raw TrueHD @tab X @tab X
  154. @item raw VC-1 @tab @tab X
  155. @item raw PCM A-law @tab X @tab X
  156. @item raw PCM mu-law @tab X @tab X
  157. @item raw PCM signed 8 bit @tab X @tab X
  158. @item raw PCM signed 16 bit big-endian @tab X @tab X
  159. @item raw PCM signed 16 bit little-endian @tab X @tab X
  160. @item raw PCM signed 24 bit big-endian @tab X @tab X
  161. @item raw PCM signed 24 bit little-endian @tab X @tab X
  162. @item raw PCM signed 32 bit big-endian @tab X @tab X
  163. @item raw PCM signed 32 bit little-endian @tab X @tab X
  164. @item raw PCM unsigned 8 bit @tab X @tab X
  165. @item raw PCM unsigned 16 bit big-endian @tab X @tab X
  166. @item raw PCM unsigned 16 bit little-endian @tab X @tab X
  167. @item raw PCM unsigned 24 bit big-endian @tab X @tab X
  168. @item raw PCM unsigned 24 bit little-endian @tab X @tab X
  169. @item raw PCM unsigned 32 bit big-endian @tab X @tab X
  170. @item raw PCM unsigned 32 bit little-endian @tab X @tab X
  171. @item raw PCM floating-point 32 bit big-endian @tab X @tab X
  172. @item raw PCM floating-point 32 bit little-endian @tab X @tab X
  173. @item raw PCM floating-point 64 bit big-endian @tab X @tab X
  174. @item raw PCM floating-point 64 bit little-endian @tab X @tab X
  175. @item RDT @tab @tab X
  176. @item REDCODE R3D @tab @tab X
  177. @tab File format used by RED Digital cameras, contains JPEG 2000 frames and PCM audio.
  178. @item RealMedia @tab X @tab X
  179. @item Redirector @tab @tab X
  180. @item Renderware TeXture Dictionary @tab @tab X
  181. @item RL2 @tab @tab X
  182. @tab Audio and video format used in some games by Entertainment Software Partners.
  183. @item RPL/ARMovie @tab @tab X
  184. @item RTP @tab @tab X
  185. @item RTSP @tab @tab X
  186. @item SDP @tab @tab X
  187. @item Sega FILM/CPK @tab @tab X
  188. @tab Used in many Sega Saturn console games.
  189. @item Sierra SOL @tab @tab X
  190. @tab .sol files used in Sierra Online games.
  191. @item Sierra VMD @tab @tab X
  192. @tab Used in Sierra CD-ROM games.
  193. @item Smacker @tab @tab X
  194. @tab Multimedia format used by many games.
  195. @item Sony OpenMG (OMA) @tab @tab X
  196. @tab Audio format used in Sony Sonic Stage and Sony Vegas.
  197. @item Sony PlayStation STR @tab @tab X
  198. @item SUN AU format @tab X @tab X
  199. @item THP @tab @tab X
  200. @tab Used on the Nintendo GameCube.
  201. @item Tiertex Limited SEQ @tab @tab X
  202. @tab Tiertex .seq files used in the DOS CD-ROM version of the game Flashback.
  203. @item True Audio @tab @tab X
  204. @item VC-1 test bitstream @tab X @tab X
  205. @item WAV @tab X @tab X
  206. @item WavPack @tab @tab X
  207. @item Wing Commander III movie @tab @tab X
  208. @tab Multimedia format used in Origin's Wing Commander III computer game.
  209. @item Westwood Studios audio @tab @tab X
  210. @tab Multimedia format used in Westwood Studios games.
  211. @item Westwood Studios VQA @tab @tab X
  212. @tab Multimedia format used in Westwood Studios games.
  213. @item YUV4MPEG pipe @tab X @tab X
  214. @end multitable
  215. @code{X} means that encoding (resp. decoding) is supported.
  216. @section Image Formats
  217. FFmpeg can read and write images for each frame of a video sequence. The
  218. following image formats are supported:
  219. @multitable @columnfractions .4 .1 .1 .4
  220. @item Name @tab Encoding @tab Decoding @tab Comments
  221. @item .Y.U.V @tab X @tab X
  222. @tab one raw file per component
  223. @item animated GIF @tab X @tab X
  224. @tab Only uncompressed GIFs are generated.
  225. @item BMP @tab X @tab X
  226. @tab Microsoft BMP image
  227. @item JPEG @tab X @tab X
  228. @tab Progressive JPEG is not supported.
  229. @item JPEG 2000 @tab @tab E
  230. @tab decoding supported through external library libopenjpeg
  231. @item JPEG-LS @tab X @tab X
  232. @item LJPEG @tab X @tab
  233. @tab Lossless JPEG
  234. @item PAM @tab X @tab X
  235. @tab PAM is a PNM extension with alpha support.
  236. @item PBM @tab X @tab X
  237. @tab Portable BitMap image
  238. @item PCX @tab X @tab X
  239. @tab PC Paintbrush
  240. @item PGM @tab X @tab X
  241. @tab Portable GrayMap image
  242. @item PGMYUV @tab X @tab X
  243. @tab PGM with U and V components in YUV 4:2:0
  244. @item PNG @tab X @tab X
  245. @tab 2/4 bpp not supported yet
  246. @item PPM @tab X @tab X
  247. @tab Portable PixelMap image
  248. @item PTX @tab @tab X
  249. @tab V.Flash PTX format
  250. @item SGI @tab X @tab X
  251. @tab SGI RGB image format
  252. @item Sun Rasterfile @tab @tab X
  253. @tab Sun RAS image format
  254. @item TIFF @tab X @tab X
  255. @tab YUV, JPEG and some extension is not supported yet.
  256. @item Truevision Targa @tab X @tab X
  257. @tab Targa (.TGA) image format
  258. @end multitable
  259. @code{X} means that encoding (resp. decoding) is supported.
  260. @code{E} means that support is provided through an external library.
  261. @section Video Codecs
  262. @multitable @columnfractions .4 .1 .1 .4
  263. @item Name @tab Encoding @tab Decoding @tab Comments
  264. @item 4X Movie @tab @tab X
  265. @tab Used in certain computer games.
  266. @item 8088flex TMV @tab @tab X
  267. @item 8SVX exponential @tab @tab X
  268. @item 8SVX fibonacci @tab @tab X
  269. @item American Laser Games MM @tab @tab X
  270. @tab Used in games like Mad Dog McCree.
  271. @item AMV Video @tab @tab X
  272. @tab Used in Chinese MP3 players.
  273. @item Apple MJPEG-B @tab @tab X
  274. @item Apple QuickDraw @tab @tab X
  275. @tab fourcc: qdrw
  276. @item Asus v1 @tab X @tab X
  277. @tab fourcc: ASV1
  278. @item Asus v2 @tab X @tab X
  279. @tab fourcc: ASV2
  280. @item ATI VCR1 @tab @tab X
  281. @tab fourcc: VCR1
  282. @item ATI VCR2 @tab @tab X
  283. @tab fourcc: VCR2
  284. @item Autodesk Animator Flic video @tab @tab X
  285. @item Autodesk RLE @tab @tab X
  286. @tab fourcc: AASC
  287. @item AVS (Audio Video Standard) video @tab @tab X
  288. @tab Video encoding used by the Creature Shock game.
  289. @item Beam Software VB @tab @tab X
  290. @item Bethesda VID video @tab @tab X
  291. @tab Used in some games from Bethesda Softworks.
  292. @item Brute Force & Ignorance @tab @tab X
  293. @tab Used in the game Flash Traffic: City of Angels.
  294. @item C93 video @tab @tab X
  295. @tab Codec used in Cyberia game.
  296. @item CamStudio @tab @tab X
  297. @tab fourcc: CSCD
  298. @item Chinese AVS video @tab @tab X
  299. @tab AVS1-P2, JiZhun profile
  300. @item Delphine Software International CIN video @tab @tab X
  301. @tab Codec used in Delphine Software International games.
  302. @item Cinepak @tab @tab X
  303. @item Cirrus Logic AccuPak @tab @tab X
  304. @tab fourcc: CLJR
  305. @item Creative YUV (CYUV) @tab @tab X
  306. @item Dirac @tab E @tab E
  307. @tab supported through external libdirac/libschroedinger libraries
  308. @item DNxHD @tab X @tab X
  309. @tab aka SMPTE VC3
  310. @item Duck TrueMotion 1.0 @tab @tab X
  311. @tab fourcc: DUCK
  312. @item Duck TrueMotion 2.0 @tab @tab X
  313. @tab fourcc: TM20
  314. @item DV (Digital Video) @tab X @tab X
  315. @item Feeble Files/ScummVM DXA @tab @tab X
  316. @tab Codec originally used in Feeble Files game.
  317. @item Electronic Arts CMV video @tab @tab X
  318. @tab Used in NHL 95 game.
  319. @item Electronic Arts TGV video @tab @tab X
  320. @item Electronic Arts TGQ video @tab @tab X
  321. @item Electronic Arts TQI video @tab @tab X
  322. @item Escape 124 @tab @tab X
  323. @item FFmpeg codec #1 @tab X @tab X
  324. @tab experimental lossless codec (fourcc: FFV1)
  325. @item Flash Screen Video v1 @tab X @tab X
  326. @tab fourcc: FSV1
  327. @item Flash Video (FLV) @tab X @tab X
  328. @tab Sorenson H.263 used in Flash
  329. @item Fraps @tab @tab X
  330. @item H.261 @tab X @tab X
  331. @item H.263 / H.263-1996 @tab X @tab X
  332. @item H.263+ / H.263-1998 / H.263 version 2 @tab X @tab X
  333. @item H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10 @tab E @tab X
  334. @tab encoding supported through external library libx264
  335. @item H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10 (VDPAU acceleration) @tab E @tab X
  336. @item HuffYUV @tab X @tab X
  337. @item HuffYUV FFmpeg variant @tab X @tab X
  338. @item IBM Ultimotion @tab @tab X
  339. @tab fourcc: ULTI
  340. @item id Cinematic video @tab @tab X
  341. @tab Used in Quake II.
  342. @item id RoQ video @tab X @tab X
  343. @tab Used in Quake III, Jedi Knight 2, other computer games.
  344. @item Intel H.263 @tab @tab X
  345. @item Intel Indeo 2 @tab @tab X
  346. @item Intel Indeo 3 @tab @tab X
  347. @item Interplay C93 @tab @tab X
  348. @tab Used in the game Cyberia from Interplay.
  349. @item Interplay MVE video @tab @tab X
  350. @tab Used in Interplay .MVE files.
  351. @item Karl Morton's video codec @tab @tab X
  352. @tab Codec used in Worms games.
  353. @item LCL (LossLess Codec Library) MSZH @tab @tab X
  354. @item LCL (LossLess Codec Library) ZLIB @tab E @tab E
  355. @item LOCO @tab @tab X
  356. @item lossless MJPEG @tab X @tab X
  357. @item Microsoft RLE @tab @tab X
  358. @item Microsoft Video 1 @tab @tab X
  359. @item Mimic @tab @tab X
  360. @tab Used in MSN Messenger Webcam streams.
  361. @item Miro VideoXL @tab @tab X
  362. @tab fourcc: VIXL
  363. @item MJPEG (Motion JPEG) @tab X @tab X
  364. @item Motion Pixels video @tab @tab X
  365. @item MPEG-1 video @tab X @tab X
  366. @item MPEG-1/2 video XvMC (X-Video Motion Compensation) @tab @tab X
  367. @item MPEG-1/2 video (VDPAU acceleration) @tab @tab X
  368. @item MPEG-2 video @tab X @tab X
  369. @item MPEG-4 part 2 @tab X @tab X
  370. @ libxvidcore can be used alternatively for encoding.
  371. @item MPEG-4 part 2 Microsoft variant version 1 @tab X @tab X
  372. @item MPEG-4 part 2 Microsoft variant version 2 @tab X @tab X
  373. @item MPEG-4 part 2 Microsoft variant version 3 @tab X @tab X
  374. @item Nintendo Gamecube THP video @tab @tab X
  375. @item NuppelVideo/RTjpeg @tab @tab X
  376. @tab Video encoding used in NuppelVideo files.
  377. @item On2 VP3 @tab @tab X
  378. @tab still experimental
  379. @item On2 VP5 @tab @tab X
  380. @tab fourcc: VP50
  381. @item On2 VP6 @tab @tab X
  382. @tab fourcc: VP60,VP61,VP62
  383. @item planar RGB @tab @tab X
  384. @tab fourcc: 8BPS
  385. @item Q-team QPEG @tab @tab X
  386. @tab fourccs: QPEG, Q1.0, Q1.1
  387. @item QuickTime 8BPS video @tab @tab X
  388. @item QuickTime Animation (RLE) video @tab X @tab X
  389. @tab fourcc: 'rle '
  390. @item QuickTime Graphics (SMC) @tab @tab X
  391. @tab fourcc: 'smc '
  392. @item QuickTime video (RPZA) @tab @tab X
  393. @tab fourcc: rpza
  394. @item Raw Video @tab X @tab X
  395. @item RealVideo 1.0 @tab X @tab X
  396. @item RealVideo 2.0 @tab X @tab X
  397. @item RealVideo 3.0 @tab @tab X
  398. @tab still far from ideal
  399. @item RealVideo 4.0 @tab @tab X
  400. @item Renderware TXD (TeXture Dictionary) @tab @tab X
  401. @tab Texture dictionaries used by the Renderware Engine.
  402. @item RL2 video @tab @tab X
  403. @tab used in some games by Entertainment Software Partners
  404. @item Sierra VMD video @tab @tab X
  405. @tab Used in Sierra VMD files.
  406. @item Smacker video @tab @tab X
  407. @tab Video encoding used in Smacker.
  408. @item SMPTE VC-1 @tab @tab X
  409. @item Snow @tab X @tab X
  410. @tab experimental wavelet codec (fourcc: SNOW)
  411. @item Sony PlayStation MDEC (Motion DECoder) @tab @tab X
  412. @item Sorenson Vector Quantizer 1 @tab X @tab X
  413. @tab fourcc: SVQ1
  414. @item Sorenson Vector Quantizer 3 @tab @tab X
  415. @tab fourcc: SVQ3
  416. @item Sunplus JPEG (SP5X) @tab @tab X
  417. @tab fourcc: SP5X
  418. @item TechSmith Screen Capture Codec @tab @tab X
  419. @tab fourcc: TSCC
  420. @item Theora @tab E @tab X
  421. @tab encoding supported through external library libtheora
  422. @item Tiertex Limited SEQ video @tab @tab X
  423. @tab Codec used in DOS CD-ROM FlashBack game.
  424. @item V210 Quicktime Uncompressed 4:2:2 10-bit @tab X @tab X
  425. @item VMware Screen Codec / VMware Video @tab @tab X
  426. @tab Codec used in videos captured by VMware.
  427. @item Westwood Studios VQA (Vector Quantized Animation) video @tab @tab X
  428. @item Windows Media Video 7 @tab X @tab X
  429. @item Windows Media Video 8 @tab X @tab X
  430. @item Windows Media Video 9 @tab @tab X
  431. @tab not completely working
  432. @item Wing Commander III / Xan @tab @tab X
  433. @tab Used in Wing Commander III .MVE files.
  434. @item Winnov WNV1 @tab @tab X
  435. @item WMV7 @tab X @tab X
  436. @item YAMAHA SMAF @tab X @tab X
  437. @item ZLIB @tab X @tab X
  438. @tab part of LCL, encoder experimental
  439. @item Zip Motion Blocks Video @tab X @tab X
  440. @tab Encoder works only in PAL8.
  441. @end multitable
  442. @code{X} means that encoding (resp. decoding) is supported.
  443. @code{E} means that support is provided through an external library.
  444. @section Audio Codecs
  445. @multitable @columnfractions .4 .1 .1 .4
  446. @item Name @tab Encoding @tab Decoding @tab Comments
  447. @item 8SVX audio @tab @tab X
  448. @item AAC @tab E @tab X
  449. @tab encoding supported through external library libfaac
  450. @item AC-3 @tab IX @tab X
  451. @item ADPCM 4X Movie @tab @tab X
  452. @item ADPCM CDROM XA @tab @tab X
  453. @item ADPCM Creative Technology @tab @tab X
  454. @tab 16 -> 4, 8 -> 4, 8 -> 3, 8 -> 2
  455. @item ADPCM Electronic Arts @tab @tab X
  456. @tab Used in various EA titles.
  457. @item ADPCM Electronic Arts Maxis CDROM XS @tab @tab X
  458. @tab Used in Sim City 3000.
  459. @item ADPCM Electronic Arts R1 @tab @tab X
  460. @item ADPCM Electronic Arts R2 @tab @tab X
  461. @item ADPCM Electronic Arts R3 @tab @tab X
  462. @item ADPCM Electronic Arts XAS @tab @tab X
  463. @item ADPCM G.726 @tab X @tab X
  464. @item ADPCM IMA AMV @tab @tab X
  465. @tab Used in AMV files
  466. @item ADPCM IMA Electronic Arts EACS @tab @tab X
  467. @item ADPCM IMA Electronic Arts SEAD @tab @tab X
  468. @item ADPCM IMA Funcom @tab @tab X
  469. @item ADPCM IMA QuickTime @tab X @tab X
  470. @item ADPCM IMA Loki SDL MJPEG @tab @tab X
  471. @item ADPCM IMA WAV @tab X @tab X
  472. @item ADPCM IMA Westwood @tab @tab X
  473. @item ADPCM ISS IMA @tab @tab X
  474. @tab Used in FunCom games.
  475. @item ADPCM IMA Duck DK3 @tab @tab X
  476. @tab Used in some Sega Saturn console games.
  477. @item ADPCM IMA Duck DK4 @tab @tab X
  478. @tab Used in some Sega Saturn console games.
  479. @item ADPCM Microsoft @tab X @tab X
  480. @item ADPCM MS IMA @tab X @tab X
  481. @item ADPCM Nintendo Gamecube THP @tab @tab X
  482. @item ADPCM QT IMA @tab X @tab X
  483. @item ADPCM SEGA CRI ADX @tab X @tab X
  484. @tab Used in Sega Dreamcast games.
  485. @item ADPCM Shockwave Flash @tab X @tab X
  486. @item ADPCM SMJPEG IMA @tab @tab X
  487. @tab Used in certain Loki game ports.
  488. @item ADPCM Sound Blaster Pro 2-bit @tab @tab X
  489. @item ADPCM Sound Blaster Pro 2.6-bit @tab @tab X
  490. @item ADPCM Sound Blaster Pro 4-bit @tab @tab X
  491. @item ADPCM Westwood Studios IMA @tab @tab X
  492. @tab Used in Westwood Studios games like Command and Conquer.
  493. @item ADPCM Yamaha @tab X @tab X
  494. @item AMR-NB @tab E @tab E
  495. @tab supported through external library libamrnb
  496. @item AMR-WB @tab E @tab E
  497. @tab supported through external library libamrwb
  498. @item Apple lossless audio @tab X @tab X
  499. @tab QuickTime fourcc 'alac'
  500. @item Atrac 3 @tab @tab X
  501. @item Delphine Software International CIN audio @tab @tab X
  502. @tab Codec used in Delphine Software International games.
  503. @item COOK @tab @tab X
  504. @tab All versions except 5.1 are supported.
  505. @item DCA (DTS Coherent Acoustics) @tab @tab X
  506. @item DPCM id RoQ @tab X @tab X
  507. @tab Used in Quake III, Jedi Knight 2, other computer games.
  508. @item DPCM Interplay @tab @tab X
  509. @tab Used in various Interplay computer games.
  510. @item DPCM Sierra Online @tab @tab X
  511. @tab Used in Sierra Online game audio files.
  512. @item DPCM Sol @tab @tab X
  513. @item DPCM Xan @tab @tab X
  514. @item DSP Group TrueSpeech @tab @tab X
  515. @item DV audio @tab @tab X
  516. @item Enhanced AC-3 @tab @tab X
  517. @item FLAC (Free Lossless Audio Codec) @tab X @tab IX
  518. @item G.729 @tab @tab X
  519. @item GSM @tab E @tab E
  520. @tab supported through external library libgsm
  521. @item GSM Microsoft variant @tab E @tab E
  522. @tab supported through external library libgsm
  523. @item IMC (Intel Music Coder) @tab @tab X
  524. @item MACE (Macintosh Audio Compression/Expansion) 3:1 @tab @tab X
  525. @item MACE (Macintosh Audio Compression/Expansion) 6:1 @tab @tab X
  526. @item MLP (Meridian Lossless Packing) @tab @tab X
  527. @tab Used in DVD-Audio discs.
  528. @item Monkey's Audio @tab @tab X
  529. @tab Only versions 3.97-3.99 are supported.
  530. @item MP1 (MPEG audio layer 1) @tab @tab IX
  531. @item MP2 (MPEG audio layer 2) @tab IX @tab IX
  532. @item MP3 (MPEG audio layer 3) @tab E @tab IX
  533. @tab encoding supported through external library LAME, ADU MP3 and MP3onMP4 also supported
  534. @item Musepack SV7 @tab @tab X
  535. @item Musepack SV8 @tab @tab X
  536. @item Nellymoser Asao @tab X @tab X
  537. @item PCM A-law @tab X @tab X
  538. @item PCM mu-law @tab X @tab X
  539. @item PCM 16-bit little-endian planar @tab @tab X
  540. @item PCM 32-bit floating point big-endian @tab X @tab X
  541. @item PCM 32-bit floating point little-endian @tab X @tab X
  542. @item PCM 64-bit floating point big-endian @tab X @tab X
  543. @item PCM 64-bit floating point little-endian @tab X @tab X
  544. @item PCM D-Cinema audio signed 24-bit @tab X @tab X
  545. @item PCM signed 8-bit @tab X @tab X
  546. @item PCM signed 16-bit big-endian @tab X @tab X
  547. @item PCM signed 16-bit little-endian @tab X @tab X
  548. @item PCM signed 24-bit big-endian @tab X @tab X
  549. @item PCM signed 24-bit little-endian @tab X @tab X
  550. @item PCM signed 32-bit big-endian @tab X @tab X
  551. @item PCM signed 32-bit little-endian @tab X @tab X
  552. @item PCM unsigned 8-bit @tab X @tab X
  553. @item PCM unsigned 16-bit big-endian @tab X @tab X
  554. @item PCM unsigned 16-bit little-endian @tab X @tab X
  555. @item PCM unsigned 24-bit big-endian @tab X @tab X
  556. @item PCM unsigned 24-bit little-endian @tab X @tab X
  557. @item PCM unsigned 32-bit big-endian @tab X @tab X
  558. @item PCM unsigned 32-bit little-endian @tab X @tab X
  559. @item PCM Zork @tab X @tab X
  560. @item QCELP / PureVoice @tab @tab X
  561. @item QDesign Music Codec 2 @tab @tab X
  562. @tab There are still some distortions.
  563. @item RealAudio 1.0 (14.4K) @tab @tab X
  564. @tab Real 14400 bit/s codec
  565. @item RealAudio 2.0 (28.8K) @tab @tab X
  566. @tab Real 28800 bit/s codec
  567. @item RealAudio 3.0 (dnet) @tab IX @tab X
  568. @tab Real low bitrate AC-3 codec
  569. @item Shorten @tab @tab X
  570. @item Sierra VMD audio @tab @tab X
  571. @tab Used in Sierra VMD files.
  572. @item Smacker audio @tab @tab X
  573. @item Sonic @tab X @tab X
  574. @tab experimental codec
  575. @item Sonic lossless @tab X @tab X
  576. @tab experimental codec
  577. @item Speex @tab @tab E
  578. @tab supported through external library libspeex
  579. @item True Audio (TTA) @tab @tab X
  580. @item TrueHD @tab @tab X
  581. @tab Used in HD-DVD and Blu-Ray discs.
  582. @item Vorbis @tab E @tab X
  583. @ A native but very primitive encoder exists.
  584. @item WavPack @tab @tab X
  585. @item Westwood Audio (SND1) @tab @tab X
  586. @item Windows Media Audio 1 @tab X @tab X
  587. @item Windows Media Audio 2 @tab X @tab X
  588. @tab Used in Origin's Wing Commander IV AVI files.
  589. @end multitable
  590. @code{X} means that encoding (resp. decoding) is supported.
  591. @code{E} means that support is provided through an external library.
  592. @code{I} means that an integer-only version is available, too (ensures high
  593. performance on systems without hardware floating point support).
  594. @section Subtitle Formats
  595. @multitable @columnfractions .4 .1 .1 .1 .1
  596. @item Name @tab Muxing @tab Demuxing @tab Encoding @tab Decoding
  597. @item SSA/ASS @tab X @tab X
  598. @item DVB @tab X @tab X @tab X @tab X
  599. @item DVD @tab X @tab X @tab X @tab X
  600. @item XSUB @tab @tab @tab @tab X
  601. @end multitable
  602. @code{X} means that the feature is supported.
  603. @section Network Protocols
  604. @multitable @columnfractions .4 .1
  605. @item Name @tab Support
  606. @item file @tab X
  607. @item Gopher @tab X
  608. @item HTTP @tab X
  609. @item pipe @tab X
  610. @item RTP @tab X
  611. @item TCP @tab X
  612. @item UDP @tab X
  613. @end multitable
  614. @code{X} means that the protocol is supported.
  615. @section Input/Output Devices
  616. @multitable @columnfractions .4 .1 .1
  617. @item Name @tab Input @tab Output
  618. @item ALSA @tab X @tab X
  619. @item BEOS audio @tab X @tab X
  620. @item BKTR @tab X @tab
  621. @item DV1394 @tab X @tab
  622. @item JACK @tab X @tab
  623. @item LIBDC1394 @tab X @tab
  624. @item OSS @tab X @tab X
  625. @item Video4Linux @tab X @tab
  626. @item Video4Linux2 @tab X @tab
  627. @item VfW capture @tab X @tab
  628. @item X11 grabbing @tab X @tab
  629. @end multitable
  630. @code{X} means that input/output is supported.
  631. @chapter Platform Specific information
  632. @section BSD
  633. BSD make will not build FFmpeg, you need to install and use GNU Make
  634. (@file{gmake}).
  635. @section Windows
  636. To get help and instructions for building FFmpeg under Windows, check out
  637. the FFmpeg Windows Help Forum at
  638. @url{http://ffmpeg.arrozcru.org/}.
  639. @subsection Native Windows compilation
  640. FFmpeg can be built to run natively on Windows using the MinGW tools. Install
  641. the latest versions of MSYS and MinGW from @url{http://www.mingw.org/}.
  642. You can find detailed installation
  643. instructions in the download section and the FAQ.
  644. FFmpeg does not build out-of-the-box with the packages the automated MinGW
  645. installer provides. It also requires coreutils to be installed and many other
  646. packages updated to the latest version. The minimum version for some packages
  647. are listed below:
  648. @itemize
  649. @item bash 3.1
  650. @item msys-make 3.81-2 (note: not mingw32-make)
  651. @item w32api 3.13
  652. @item mingw-runtime 3.15
  653. @end itemize
  654. FFmpeg automatically passes @code{-fno-common} to the compiler to work around
  655. a GCC bug (see @url{http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37216}).
  656. Within the MSYS shell, configure and make with:
  657. @example
  658. ./configure --enable-memalign-hack --extra-cflags=-fno-common
  659. make
  660. make install
  661. @end example
  662. This will install @file{ffmpeg.exe} along with many other development files
  663. to @file{/usr/local}. You may specify another install path using the
  664. @code{--prefix} option in @file{configure}.
  665. Notes:
  666. @itemize
  667. @item In order to compile FFplay, you must have the MinGW development library
  668. of SDL. Get it from @url{http://www.libsdl.org}.
  669. Edit the @file{bin/sdl-config} script so that it points to the correct prefix
  670. where SDL was installed. Verify that @file{sdl-config} can be launched from
  671. the MSYS command line.
  672. @item By using @code{./configure --enable-shared} when configuring FFmpeg,
  673. you can build libavutil, libavcodec and libavformat as DLLs.
  674. @end itemize
  675. @subsection Microsoft Visual C++ compatibility
  676. As stated in the FAQ, FFmpeg will not compile under MSVC++. However, if you
  677. want to use the libav* libraries in your own applications, you can still
  678. compile those applications using MSVC++. But the libav* libraries you link
  679. to @emph{must} be built with MinGW. However, you will not be able to debug
  680. inside the libav* libraries, since MSVC++ does not recognize the debug
  681. symbols generated by GCC.
  682. We strongly recommend you to move over from MSVC++ to MinGW tools.
  683. This description of how to use the FFmpeg libraries with MSVC++ is based on
  684. Microsoft Visual C++ 2005 Express Edition. If you have a different version,
  685. you might have to modify the procedures slightly.
  686. @subsubsection Using static libraries
  687. Assuming you have just built and installed FFmpeg in @file{/usr/local}.
  688. @enumerate
  689. @item Create a new console application ("File / New / Project") and then
  690. select "Win32 Console Application". On the appropriate page of the
  691. Application Wizard, uncheck the "Precompiled headers" option.
  692. @item Write the source code for your application, or, for testing, just
  693. copy the code from an existing sample application into the source file
  694. that MSVC++ has already created for you. For example, you can copy
  695. @file{libavformat/output-example.c} from the FFmpeg distribution.
  696. @item Open the "Project / Properties" dialog box. In the "Configuration"
  697. combo box, select "All Configurations" so that the changes you make will
  698. affect both debug and release builds. In the tree view on the left hand
  699. side, select "C/C++ / General", then edit the "Additional Include
  700. Directories" setting to contain the path where the FFmpeg includes were
  701. installed (i.e. @file{c:\msys\1.0\local\include}).
  702. Do not add MinGW's include directory here, or the include files will
  703. conflict with MSVC's.
  704. @item Still in the "Project / Properties" dialog box, select
  705. "Linker / General" from the tree view and edit the
  706. "Additional Library Directories" setting to contain the @file{lib}
  707. directory where FFmpeg was installed (i.e. @file{c:\msys\1.0\local\lib}),
  708. the directory where MinGW libs are installed (i.e. @file{c:\mingw\lib}),
  709. and the directory where MinGW's GCC libs are installed
  710. (i.e. @file{C:\mingw\lib\gcc\mingw32\4.2.1-sjlj}). Then select
  711. "Linker / Input" from the tree view, and add the files @file{libavformat.a},
  712. @file{libavcodec.a}, @file{libavutil.a}, @file{libmingwex.a},
  713. @file{libgcc.a}, and any other libraries you used (i.e. @file{libz.a})
  714. to the end of "Additional Dependencies".
  715. @item Now, select "C/C++ / Code Generation" from the tree view. Select
  716. "Debug" in the "Configuration" combo box. Make sure that "Runtime
  717. Library" is set to "Multi-threaded Debug DLL". Then, select "Release" in
  718. the "Configuration" combo box and make sure that "Runtime Library" is
  719. set to "Multi-threaded DLL".
  720. @item Click "OK" to close the "Project / Properties" dialog box.
  721. @item MSVC++ lacks some C99 header files that are fundamental for FFmpeg.
  722. Get msinttypes from @url{http://code.google.com/p/msinttypes/downloads/list}
  723. and install it in MSVC++'s include directory
  724. (i.e. @file{C:\Program Files\Microsoft Visual Studio 8\VC\include}).
  725. @item MSVC++ also does not understand the @code{inline} keyword used by
  726. FFmpeg, so you must add this line before @code{#include}ing libav*:
  727. @example
  728. #define inline _inline
  729. @end example
  730. @item Build your application, everything should work.
  731. @end enumerate
  732. @subsubsection Using shared libraries
  733. This is how to create DLL and LIB files that are compatible with MSVC++:
  734. @enumerate
  735. @item Add a call to @file{vcvars32.bat} (which sets up the environment
  736. variables for the Visual C++ tools) as the first line of @file{msys.bat}.
  737. The standard location for @file{vcvars32.bat} is
  738. @file{C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat},
  739. and the standard location for @file{msys.bat} is @file{C:\msys\1.0\msys.bat}.
  740. If this corresponds to your setup, add the following line as the first line
  741. of @file{msys.bat}:
  742. @example
  743. call "C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat"
  744. @end example
  745. Alternatively, you may start the @file{Visual Studio 2005 Command Prompt},
  746. and run @file{c:\msys\1.0\msys.bat} from there.
  747. @item Within the MSYS shell, run @code{lib.exe}. If you get a help message
  748. from @file{Microsoft (R) Library Manager}, this means your environment
  749. variables are set up correctly, the @file{Microsoft (R) Library Manager}
  750. is on the path and will be used by FFmpeg to create
  751. MSVC++-compatible import libraries.
  752. @item Build FFmpeg with
  753. @example
  754. ./configure --enable-shared --enable-memalign-hack
  755. make
  756. make install
  757. @end example
  758. Your install path (@file{/usr/local/} by default) should now have the
  759. necessary DLL and LIB files under the @file{bin} directory.
  760. @end enumerate
  761. To use those files with MSVC++, do the same as you would do with
  762. the static libraries, as described above. But in Step 4,
  763. you should only need to add the directory where the LIB files are installed
  764. (i.e. @file{c:\msys\usr\local\bin}). This is not a typo, the LIB files are
  765. installed in the @file{bin} directory. And instead of adding @file{libxx.a}
  766. files, you should add @file{avcodec.lib}, @file{avformat.lib}, and
  767. @file{avutil.lib}. There should be no need for @file{libmingwex.a},
  768. @file{libgcc.a}, and @file{wsock32.lib}, nor any other external library
  769. statically linked into the DLLs. The @file{bin} directory contains a bunch
  770. of DLL files, but the ones that are actually used to run your application
  771. are the ones with a major version number in their filenames
  772. (i.e. @file{avcodec-51.dll}).
  773. @subsection Cross compilation for Windows with Linux
  774. You must use the MinGW cross compilation tools available at
  775. @url{http://www.mingw.org/}.
  776. Then configure FFmpeg with the following options:
  777. @example
  778. ./configure --target-os=mingw32 --cross-prefix=i386-mingw32msvc-
  779. @end example
  780. (you can change the cross-prefix according to the prefix chosen for the
  781. MinGW tools).
  782. Then you can easily test FFmpeg with Wine
  783. (@url{http://www.winehq.com/}).
  784. @subsection Compilation under Cygwin
  785. The main issue with the 1.5.x Cygwin versions is that newlib, its C library,
  786. does not contain llrint(). You need to upgrade to the unstable 1.7.x versions,
  787. or leverage the implementation in MinGW (as explained below).
  788. Just install your Cygwin with all the "Base" packages, plus the
  789. following "Devel" ones:
  790. @example
  791. binutils, gcc-core, make, subversion, mingw-runtime, diffutils
  792. @end example
  793. The experimental gcc4 package is still buggy, hence please
  794. use the official gcc 3.4.4 or a 4.2.x compiled from source by yourself.
  795. Install the current binutils-20080624-2 as they work fine (the old
  796. binutils-20060709-1 proved buggy on shared builds).
  797. Then create a small library that just contains llrint():
  798. @example
  799. ar x /usr/lib/mingw/libmingwex.a llrint.o
  800. ar cq /usr/local/lib/libllrint.a llrint.o
  801. @end example
  802. Then run
  803. @example
  804. ./configure --enable-static --disable-shared --extra-ldflags='-L /usr/local/lib' --extra-libs='-l llrint'
  805. @end example
  806. to make a static build or
  807. @example
  808. ./configure --enable-shared --disable-static --extra-ldflags='-L /usr/local/lib' --extra-libs='-l llrint'
  809. @end example
  810. to build shared libraries.
  811. If you want to build FFmpeg with additional libraries, download Cygwin
  812. "Devel" packages for Ogg and Vorbis from any Cygwin packages repository:
  813. @example
  814. libogg-devel, libvorbis-devel
  815. @end example
  816. These library packages are only available from Cygwin Ports
  817. (@url{http://sourceware.org/cygwinports/}) :
  818. @example
  819. yasm, libSDL-devel, libdirac-devel, libfaac-devel, libfaad-devel, libgsm-devel,
  820. libmp3lame-devel, libschroedinger1.0-devel, speex-devel, libtheora-devel,
  821. libxvidcore-devel
  822. @end example
  823. The recommendation for libnut and x264 is to build them from source by
  824. yourself, as they evolve too quickly for Cygwin Ports to be up to date.
  825. Cygwin 1.7.x has IPv6 support. You can add IPv6 to Cygwin 1.5.x by means
  826. of the @code{libgetaddrinfo-devel} package, available at Cygwin Ports.
  827. @subsection Crosscompilation for Windows under Cygwin
  828. With Cygwin you can create Windows binaries that do not need the cygwin1.dll.
  829. Just install your Cygwin as explained before, plus these additional
  830. "Devel" packages:
  831. @example
  832. gcc-mingw-core, mingw-runtime, mingw-zlib
  833. @end example
  834. and add some special flags to your configure invocation.
  835. For a static build run
  836. @example
  837. ./configure --target-os=mingw32 --enable-memalign-hack --enable-static --disable-shared --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
  838. @end example
  839. and for a build with shared libraries
  840. @example
  841. ./configure --target-os=mingw32 --enable-memalign-hack --enable-shared --disable-static --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
  842. @end example
  843. @section BeOS
  844. BeOS support is broken in mysterious ways.
  845. @section OS/2
  846. For information about compiling FFmpeg on OS/2 see
  847. @url{http://www.edm2.com/index.php/FFmpeg}.
  848. @chapter Developers Guide
  849. @section API
  850. @itemize @bullet
  851. @item libavcodec is the library containing the codecs (both encoding and
  852. decoding). Look at @file{libavcodec/apiexample.c} to see how to use it.
  853. @item libavformat is the library containing the file format handling (mux and
  854. demux code for several formats). Look at @file{ffplay.c} to use it in a
  855. player. See @file{libavformat/output-example.c} to use it to generate
  856. audio or video streams.
  857. @end itemize
  858. @section Integrating libavcodec or libavformat in your program
  859. You can integrate all the source code of the libraries to link them
  860. statically to avoid any version problem. All you need is to provide a
  861. 'config.mak' and a 'config.h' in the parent directory. See the defines
  862. generated by ./configure to understand what is needed.
  863. You can use libavcodec or libavformat in your commercial program, but
  864. @emph{any patch you make must be published}. The best way to proceed is
  865. to send your patches to the FFmpeg mailing list.
  866. @node Coding Rules
  867. @section Coding Rules
  868. FFmpeg is programmed in the ISO C90 language with a few additional
  869. features from ISO C99, namely:
  870. @itemize @bullet
  871. @item
  872. the @samp{inline} keyword;
  873. @item
  874. @samp{//} comments;
  875. @item
  876. designated struct initializers (@samp{struct s x = @{ .i = 17 @};})
  877. @item
  878. compound literals (@samp{x = (struct s) @{ 17, 23 @};})
  879. @end itemize
  880. These features are supported by all compilers we care about, so we will not
  881. accept patches to remove their use unless they absolutely do not impair
  882. clarity and performance.
  883. All code must compile with GCC 2.95 and GCC 3.3. Currently, FFmpeg also
  884. compiles with several other compilers, such as the Compaq ccc compiler
  885. or Sun Studio 9, and we would like to keep it that way unless it would
  886. be exceedingly involved. To ensure compatibility, please do not use any
  887. additional C99 features or GCC extensions. Especially watch out for:
  888. @itemize @bullet
  889. @item
  890. mixing statements and declarations;
  891. @item
  892. @samp{long long} (use @samp{int64_t} instead);
  893. @item
  894. @samp{__attribute__} not protected by @samp{#ifdef __GNUC__} or similar;
  895. @item
  896. GCC statement expressions (@samp{(x = (@{ int y = 4; y; @})}).
  897. @end itemize
  898. Indent size is 4.
  899. The presentation is the one specified by 'indent -i4 -kr -nut'.
  900. The TAB character is forbidden outside of Makefiles as is any
  901. form of trailing whitespace. Commits containing either will be
  902. rejected by the Subversion repository.
  903. The main priority in FFmpeg is simplicity and small code size in order to
  904. minimize the bug count.
  905. Comments: Use the JavaDoc/Doxygen
  906. format (see examples below) so that code documentation
  907. can be generated automatically. All nontrivial functions should have a comment
  908. above them explaining what the function does, even if it is just one sentence.
  909. All structures and their member variables should be documented, too.
  910. @example
  911. /**
  912. * @@file mpeg.c
  913. * MPEG codec.
  914. * @@author ...
  915. */
  916. /**
  917. * Summary sentence.
  918. * more text ...
  919. * ...
  920. */
  921. typedef struct Foobar@{
  922. int var1; /**< var1 description */
  923. int var2; ///< var2 description
  924. /** var3 description */
  925. int var3;
  926. @} Foobar;
  927. /**
  928. * Summary sentence.
  929. * more text ...
  930. * ...
  931. * @@param my_parameter description of my_parameter
  932. * @@return return value description
  933. */
  934. int myfunc(int my_parameter)
  935. ...
  936. @end example
  937. fprintf and printf are forbidden in libavformat and libavcodec,
  938. please use av_log() instead.
  939. Casts should be used only when necessary. Unneeded parentheses
  940. should also be avoided if they don't make the code easier to understand.
  941. @section Development Policy
  942. @enumerate
  943. @item
  944. Contributions should be licensed under the LGPL 2.1, including an
  945. "or any later version" clause, or the MIT license. GPL 2 including
  946. an "or any later version" clause is also acceptable, but LGPL is
  947. preferred.
  948. @item
  949. You must not commit code which breaks FFmpeg! (Meaning unfinished but
  950. enabled code which breaks compilation or compiles but does not work or
  951. breaks the regression tests)
  952. You can commit unfinished stuff (for testing etc), but it must be disabled
  953. (#ifdef etc) by default so it does not interfere with other developers'
  954. work.
  955. @item
  956. You do not have to over-test things. If it works for you, and you think it
  957. should work for others, then commit. If your code has problems
  958. (portability, triggers compiler bugs, unusual environment etc) they will be
  959. reported and eventually fixed.
  960. @item
  961. Do not commit unrelated changes together, split them into self-contained
  962. pieces. Also do not forget that if part B depends on part A, but A does not
  963. depend on B, then A can and should be committed first and separate from B.
  964. Keeping changes well split into self-contained parts makes reviewing and
  965. understanding them on the commit log mailing list easier. This also helps
  966. in case of debugging later on.
  967. Also if you have doubts about splitting or not splitting, do not hesitate to
  968. ask/discuss it on the developer mailing list.
  969. @item
  970. Do not change behavior of the program (renaming options etc) without
  971. first discussing it on the ffmpeg-devel mailing list. Do not remove
  972. functionality from the code. Just improve!
  973. Note: Redundant code can be removed.
  974. @item
  975. Do not commit changes to the build system (Makefiles, configure script)
  976. which change behavior, defaults etc, without asking first. The same
  977. applies to compiler warning fixes, trivial looking fixes and to code
  978. maintained by other developers. We usually have a reason for doing things
  979. the way we do. Send your changes as patches to the ffmpeg-devel mailing
  980. list, and if the code maintainers say OK, you may commit. This does not
  981. apply to files you wrote and/or maintain.
  982. @item
  983. We refuse source indentation and other cosmetic changes if they are mixed
  984. with functional changes, such commits will be rejected and removed. Every
  985. developer has his own indentation style, you should not change it. Of course
  986. if you (re)write something, you can use your own style, even though we would
  987. prefer if the indentation throughout FFmpeg was consistent (Many projects
  988. force a given indentation style - we do not.). If you really need to make
  989. indentation changes (try to avoid this), separate them strictly from real
  990. changes.
  991. NOTE: If you had to put if()@{ .. @} over a large (> 5 lines) chunk of code,
  992. then either do NOT change the indentation of the inner part within (do not
  993. move it to the right)! or do so in a separate commit
  994. @item
  995. Always fill out the commit log message. Describe in a few lines what you
  996. changed and why. You can refer to mailing list postings if you fix a
  997. particular bug. Comments such as "fixed!" or "Changed it." are unacceptable.
  998. @item
  999. If you apply a patch by someone else, include the name and email address in
  1000. the log message. Since the ffmpeg-cvslog mailing list is publicly
  1001. archived you should add some SPAM protection to the email address. Send an
  1002. answer to ffmpeg-devel (or wherever you got the patch from) saying that
  1003. you applied the patch.
  1004. @item
  1005. When applying patches that have been discussed (at length) on the mailing
  1006. list, reference the thread in the log message.
  1007. @item
  1008. Do NOT commit to code actively maintained by others without permission.
  1009. Send a patch to ffmpeg-devel instead. If no one answers within a reasonable
  1010. timeframe (12h for build failures and security fixes, 3 days small changes,
  1011. 1 week for big patches) then commit your patch if you think it is OK.
  1012. Also note, the maintainer can simply ask for more time to review!
  1013. @item
  1014. Subscribe to the ffmpeg-cvslog mailing list. The diffs of all commits
  1015. are sent there and reviewed by all the other developers. Bugs and possible
  1016. improvements or general questions regarding commits are discussed there. We
  1017. expect you to react if problems with your code are uncovered.
  1018. @item
  1019. Update the documentation if you change behavior or add features. If you are
  1020. unsure how best to do this, send a patch to ffmpeg-devel, the documentation
  1021. maintainer(s) will review and commit your stuff.
  1022. @item
  1023. Try to keep important discussions and requests (also) on the public
  1024. developer mailing list, so that all developers can benefit from them.
  1025. @item
  1026. Never write to unallocated memory, never write over the end of arrays,
  1027. always check values read from some untrusted source before using them
  1028. as array index or other risky things.
  1029. @item
  1030. Remember to check if you need to bump versions for the specific libav
  1031. parts (libavutil, libavcodec, libavformat) you are changing. You need
  1032. to change the version integer.
  1033. Incrementing the first component means no backward compatibility to
  1034. previous versions (e.g. removal of a function from the public API).
  1035. Incrementing the second component means backward compatible change
  1036. (e.g. addition of a function to the public API or extension of an
  1037. existing data structure).
  1038. Incrementing the third component means a noteworthy binary compatible
  1039. change (e.g. encoder bug fix that matters for the decoder).
  1040. @item
  1041. Compiler warnings indicate potential bugs or code with bad style. If a type of
  1042. warning always points to correct and clean code, that warning should
  1043. be disabled, not the code changed.
  1044. Thus the remaining warnings can either be bugs or correct code.
  1045. If it is a bug, the bug has to be fixed. If it is not, the code should
  1046. be changed to not generate a warning unless that causes a slowdown
  1047. or obfuscates the code.
  1048. @item
  1049. If you add a new file, give it a proper license header. Do not copy and
  1050. paste it from a random place, use an existing file as template.
  1051. @end enumerate
  1052. We think our rules are not too hard. If you have comments, contact us.
  1053. Note, these rules are mostly borrowed from the MPlayer project.
  1054. @section Submitting patches
  1055. First, (@pxref{Coding Rules}) above if you did not yet.
  1056. When you submit your patch, try to send a unified diff (diff '-up'
  1057. option). We cannot read other diffs :-)
  1058. Also please do not submit a patch which contains several unrelated changes.
  1059. Split it into separate, self-contained pieces. This does not mean splitting
  1060. file by file. Instead, make the patch as small as possible while still
  1061. keeping it as a logical unit that contains an individual change, even
  1062. if it spans multiple files. This makes reviewing your patches much easier
  1063. for us and greatly increases your chances of getting your patch applied.
  1064. Run the regression tests before submitting a patch so that you can
  1065. verify that there are no big problems.
  1066. Patches should be posted as base64 encoded attachments (or any other
  1067. encoding which ensures that the patch will not be trashed during
  1068. transmission) to the ffmpeg-devel mailing list, see
  1069. @url{http://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel}
  1070. It also helps quite a bit if you tell us what the patch does (for example
  1071. 'replaces lrint by lrintf'), and why (for example '*BSD isn't C99 compliant
  1072. and has no lrint()')
  1073. Also please if you send several patches, send each patch as a separate mail,
  1074. do not attach several unrelated patches to the same mail.
  1075. @section New codecs or formats checklist
  1076. @enumerate
  1077. @item
  1078. Did you use av_cold for codec initialization and close functions?
  1079. @item
  1080. Did you add a long_name under NULL_IF_CONFIG_SMALL to the AVCodec or
  1081. AVInputFormat/AVOutputFormat struct?
  1082. @item
  1083. Did you bump the minor version number in @file{avcodec.h} or
  1084. @file{avformat.h}?
  1085. @item
  1086. Did you register it in @file{allcodecs.c} or @file{allformats.c}?
  1087. @item
  1088. Did you add the CodecID to @file{avcodec.h}?
  1089. @item
  1090. If it has a fourcc, did you add it to @file{libavformat/riff.c},
  1091. even if it is only a decoder?
  1092. @item
  1093. Did you add a rule to compile the appropriate files in the Makefile?
  1094. Remember to do this even if you're just adding a format to a file that is
  1095. already being compiled by some other rule, like a raw demuxer.
  1096. @item
  1097. Did you add an entry to the table of supported formats or codecs in the
  1098. documentation?
  1099. @item
  1100. Did you add an entry in the Changelog?
  1101. @item
  1102. If it depends on a parser or a library, did you add that dependency in
  1103. configure?
  1104. @item
  1105. Did you "svn add" the appropriate files before commiting?
  1106. @end enumerate
  1107. @section patch submission checklist
  1108. @enumerate
  1109. @item
  1110. Do the regression tests pass with the patch applied?
  1111. @item
  1112. Does @code{make checkheaders} pass with the patch applied?
  1113. @item
  1114. Is the patch a unified diff?
  1115. @item
  1116. Is the patch against latest FFmpeg SVN?
  1117. @item
  1118. Are you subscribed to ffmpeg-dev?
  1119. (the list is subscribers only due to spam)
  1120. @item
  1121. Have you checked that the changes are minimal, so that the same cannot be
  1122. achieved with a smaller patch and/or simpler final code?
  1123. @item
  1124. If the change is to speed critical code, did you benchmark it?
  1125. @item
  1126. If you did any benchmarks, did you provide them in the mail?
  1127. @item
  1128. Have you checked that the patch does not introduce buffer overflows or
  1129. other security issues?
  1130. @item
  1131. Did you test your decoder or demuxer against damaged data? If no, see
  1132. tools/trasher and the noise bitstream filter. Your decoder or demuxer
  1133. should not crash or end in a (near) infinite loop when fed damaged data.
  1134. @item
  1135. Is the patch created from the root of the source tree, so it can be
  1136. applied with @code{patch -p0}?
  1137. @item
  1138. Does the patch not mix functional and cosmetic changes?
  1139. @item
  1140. Did you add tabs or trailing whitespace to the code? Both are forbidden.
  1141. @item
  1142. Is the patch attached to the email you send?
  1143. @item
  1144. Is the mime type of the patch correct? It should be text/x-diff or
  1145. text/x-patch or at least text/plain and not application/octet-stream.
  1146. @item
  1147. If the patch fixes a bug, did you provide a verbose analysis of the bug?
  1148. @item
  1149. If the patch fixes a bug, did you provide enough information, including
  1150. a sample, so the bug can be reproduced and the fix can be verified?
  1151. Note please do not attach samples >100k to mails but rather provide a
  1152. URL, you can upload to ftp://upload.ffmpeg.org
  1153. @item
  1154. Did you provide a verbose summary about what the patch does change?
  1155. @item
  1156. Did you provide a verbose explanation why it changes things like it does?
  1157. @item
  1158. Did you provide a verbose summary of the user visible advantages and
  1159. disadvantages if the patch is applied?
  1160. @item
  1161. Did you provide an example so we can verify the new feature added by the
  1162. patch easily?
  1163. @item
  1164. If you added a new file, did you insert a license header? It should be
  1165. taken from FFmpeg, not randomly copied and pasted from somewhere else.
  1166. @item
  1167. You should maintain alphabetical order in alphabetically ordered lists as
  1168. long as doing so does not break API/ABI compatibility.
  1169. @item
  1170. Lines with similar content should be aligned vertically when doing so
  1171. improves readability.
  1172. @item
  1173. Did you provide a suggestion for a clear commit log message?
  1174. @end enumerate
  1175. @section Patch review process
  1176. All patches posted to ffmpeg-devel will be reviewed, unless they contain a
  1177. clear note that the patch is not for SVN.
  1178. Reviews and comments will be posted as replies to the patch on the
  1179. mailing list. The patch submitter then has to take care of every comment,
  1180. that can be by resubmitting a changed patch or by discussion. Resubmitted
  1181. patches will themselves be reviewed like any other patch. If at some point
  1182. a patch passes review with no comments then it is approved, that can for
  1183. simple and small patches happen immediately while large patches will generally
  1184. have to be changed and reviewed many times before they are approved.
  1185. After a patch is approved it will be committed to the repository.
  1186. We will review all submitted patches, but sometimes we are quite busy so
  1187. especially for large patches this can take several weeks.
  1188. When resubmitting patches, please do not make any significant changes
  1189. not related to the comments received during review. Such patches will
  1190. be rejected. Instead, submit significant changes or new features as
  1191. separate patches.
  1192. @section Regression tests
  1193. Before submitting a patch (or committing to the repository), you should at least
  1194. test that you did not break anything.
  1195. The regression tests build a synthetic video stream and a synthetic
  1196. audio stream. These are then encoded and decoded with all codecs or
  1197. formats. The CRC (or MD5) of each generated file is recorded in a
  1198. result file. A 'diff' is launched to compare the reference results and
  1199. the result file.
  1200. The regression tests then go on to test the FFserver code with a
  1201. limited set of streams. It is important that this step runs correctly
  1202. as well.
  1203. Run 'make test' to test all the codecs and formats.
  1204. Run 'make fulltest' to test all the codecs, formats and FFserver.
  1205. [Of course, some patches may change the results of the regression tests. In
  1206. this case, the reference results of the regression tests shall be modified
  1207. accordingly].
  1208. @bye