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[libav.git] / doc / general.texi
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1\input texinfo @c -*- texinfo -*-
2
3@settitle General Documentation
4@titlepage
5@sp 7
6@center @titlefont{General Documentation}
7@sp 3
8@end titlepage
9
10
11@chapter external libraries
12
13FFmpeg can be hooked up with a number of external libraries to add support
14for more formats. None of them are used by default, their use has to be
15explicitly requested by passing the appropriate flags to @file{./configure}.
16
17@section AMR
18
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19AMR comes in two different flavors, wideband and narrowband. FFmpeg can make
20use of the AMR wideband (floating-point mode) and the AMR narrowband
21(floating-point mode) reference decoders and encoders.
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22
23Go to @url{http://www.penguin.cz/~utx/amr} and follow the instructions for
24installing the libraries. Then pass @code{--enable-libamr-nb} and/or
25@code{--enable-libamr-wb} to configure to enable the libraries.
26
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27Note that libamr is copyrighted without any sort of license grant. This means
28that you can use it if you legally obtained it but you are not allowed to
29redistribute it in any way. @strong{Any FFmpeg binaries with libamr support
30you create are non-free and unredistributable!}
31
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32
33@chapter Supported File Formats and Codecs
34
35You can use the @code{-formats} option to have an exhaustive list.
36
37@section File Formats
38
39FFmpeg supports the following file formats through the @code{libavformat}
40library:
41
42@multitable @columnfractions .4 .1 .1 .4
43@item Supported File Format @tab Encoding @tab Decoding @tab Comments
44@item MPEG audio @tab X @tab X
45@item MPEG-1 systems @tab X @tab X
46@tab muxed audio and video
47@item MPEG-2 PS @tab X @tab X
48@tab also known as @code{VOB} file
49@item MPEG-2 TS @tab @tab X
50@tab also known as DVB Transport Stream
51@item ASF@tab X @tab X
52@item AVI@tab X @tab X
53@item WAV@tab X @tab X
54@item Macromedia Flash@tab X @tab X
b264a084 55@item AVM2 (Flash 9) @tab X @tab X
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56@tab Only embedded audio is decoded.
57@item FLV @tab X @tab X
58@tab Macromedia Flash video files
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59@item RealMedia @tab X @tab X
60@item raw AC-3 @tab X @tab X
61@item raw MJPEG @tab X @tab X
62@item raw MPEG video @tab X @tab X
63@item raw PCM 8/16 bits, mu-law/A-law @tab X @tab X
64@item raw CRI ADX audio @tab X @tab X
65@item raw Shorten audio @tab @tab X
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66@item SUN AU format @tab X @tab X
67@item NUT @tab X @tab X @tab NUT Open Container Format
68@item QuickTime @tab X @tab X
69@item MPEG-4 @tab X @tab X
70@tab MPEG-4 is a variant of QuickTime.
a590faeb 71@item raw MPEG-4 video @tab X @tab X
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72@item DV @tab X @tab X
73@item 4xm @tab @tab X
74@tab 4X Technologies format, used in some games.
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75@item PlayStation STR @tab @tab X
76@item id RoQ @tab X @tab X
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77@tab Used in Quake III, Jedi Knight 2, other computer games.
78@item Interplay MVE @tab @tab X
79@tab Format used in various Interplay computer games.
80@item WC3 Movie @tab @tab X
81@tab Multimedia format used in Origin's Wing Commander III computer game.
82@item Sega FILM/CPK @tab @tab X
83@tab Used in many Sega Saturn console games.
84@item Westwood Studios VQA/AUD @tab @tab X
85@tab Multimedia formats used in Westwood Studios games.
831ec935 86@item id Cinematic (.cin) @tab @tab X
d0e1cd3d 87@tab Used in Quake II.
a590faeb 88@item FLIC @tab @tab X
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89@tab .fli/.flc files
90@item Sierra VMD @tab @tab X
91@tab Used in Sierra CD-ROM games.
92@item Sierra Online @tab @tab X
93@tab .sol files used in Sierra Online games.
e09f7d61 94@item Matroska @tab X @tab X
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95@item Electronic Arts Multimedia @tab @tab X
96@tab Used in various EA games; files have extensions like WVE and UV2.
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97@item MAXIS EA XA @tab @tab X
98@tab Used in Sim City 3000; file extension .xa.
a590faeb 99@item Nullsoft Video (NSV) @tab @tab X
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100@item ADTS AAC audio @tab X @tab X
101@item Creative VOC @tab X @tab X @tab Created for the Sound Blaster Pro.
102@item American Laser Games MM @tab @tab X
0a91f4ee 103@tab Multimedia format used in games like Mad Dog McCree.
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104@item AVS @tab @tab X
105@tab Multimedia format used by the Creature Shock game.
106@item Smacker @tab @tab X
107@tab Multimedia format used by many games.
108@item GXF @tab X @tab X
109@tab General eXchange Format SMPTE 360M, used by Thomson Grass Valley playout servers.
110@item CIN @tab @tab X
111@tab Multimedia format used by Delphine Software games.
112@item MXF @tab @tab X
113@tab Material eXchange Format SMPTE 377M, used by D-Cinema, broadcast industry.
114@item SEQ @tab @tab X
831ec935 115@tab Tiertex .seq files used in the DOS CD-ROM version of the game Flashback.
d0e1cd3d 116@item DXA @tab @tab X
0a91f4ee 117@tab This format is used in the non-Windows version of the Feeble Files game and
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118different game cutscenes repacked for use with ScummVM.
119@item THP @tab @tab X
120@tab Used on the Nintendo GameCube.
121@item C93 @tab @tab X
122@tab Used in the game Cyberia from Interplay.
123@item Bethsoft VID @tab @tab X
124@tab Used in some games from Bethesda Softworks.
125@item CRYO APC @tab @tab X
126@tab Audio format used in some games by CRYO Interactive Entertainment.
bf4a1f17 127@item Monkey's Audio @tab @tab X
66f7679c 128@item SIFF @tab @tab X
0a91f4ee 129@tab Audio and video format used in some games by Beam Software.
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130@item LMLM4 @tab @tab X
131@tab Used by Linux Media Labs MPEG-4 PCI boards
132@item PVA @tab @tab X
133@tab Used by TechnoTrend DVB PCI boards
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134@item MSN TCP Webcam @tab @tab X
135@tab Used by MSN Messenger Webcam streams.
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136@item RL2 @tab @tab X
137@tab Audio and video format used in some games by Entertainment Software Partners
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138@item IFF @tab @tab X
139@tab Interchange File Format
2003d3da 140@item BFI @tab @tab X
0a91f4ee 141@tab Brute Force & Ignorance, used in Flash Traffic: City of Angels.
f059427c 142@item OMA @tab @tab X
0a91f4ee 143@tab Audio format used in Sony Sonic Stage and Sony Vegas.
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144@end multitable
145
146@code{X} means that encoding (resp. decoding) is supported.
147
148@section Image Formats
149
150FFmpeg can read and write images for each frame of a video sequence. The
151following image formats are supported:
152
153@multitable @columnfractions .4 .1 .1 .4
154@item Supported Image Format @tab Encoding @tab Decoding @tab Comments
155@item PGM, PPM @tab X @tab X
156@item PAM @tab X @tab X @tab PAM is a PNM extension with alpha support.
157@item PGMYUV @tab X @tab X @tab PGM with U and V components in YUV 4:2:0
158@item JPEG @tab X @tab X @tab Progressive JPEG is not supported.
159@item .Y.U.V @tab X @tab X @tab one raw file per component
160@item animated GIF @tab X @tab X @tab Only uncompressed GIFs are generated.
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161@item PNG @tab X @tab X @tab 2/4 bpp not supported yet
162@item Targa @tab @tab X @tab Targa (.TGA) image format
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163@item TIFF @tab X @tab X @tab YUV, JPEG and some extension is not supported yet.
164@item SGI @tab X @tab X @tab SGI RGB image format
165@item PTX @tab @tab X @tab V.Flash PTX format
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166@item RAS @tab @tab X @tab Sun Rasterfile
167@item PCX @tab @tab X @tab PC Paintbrush
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168@end multitable
169
170@code{X} means that encoding (resp. decoding) is supported.
171
172@section Video Codecs
173
174@multitable @columnfractions .4 .1 .1 .4
175@item Supported Codec @tab Encoding @tab Decoding @tab Comments
176@item MPEG-1 video @tab X @tab X
177@item MPEG-2 video @tab X @tab X
178@item MPEG-4 @tab X @tab X
179@item MSMPEG4 V1 @tab X @tab X
180@item MSMPEG4 V2 @tab X @tab X
181@item MSMPEG4 V3 @tab X @tab X
182@item WMV7 @tab X @tab X
69cec4e3 183@item WMV8 @tab X @tab X
d0e1cd3d 184@item WMV9 @tab @tab X @tab not completely working
a590faeb 185@item VC-1 @tab @tab X
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186@item H.261 @tab X @tab X
187@item H.263(+) @tab X @tab X @tab also known as RealVideo 1.0
188@item H.264 @tab @tab X
189@item RealVideo 1.0 @tab X @tab X
190@item RealVideo 2.0 @tab X @tab X
191@item MJPEG @tab X @tab X
192@item lossless MJPEG @tab X @tab X
0a91f4ee 193@item JPEG-LS @tab X @tab X @tab fourcc: MJLS, lossless and near-lossless is supported.
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194@item Apple MJPEG-B @tab @tab X
195@item Sunplus MJPEG @tab @tab X @tab fourcc: SP5X
196@item DV @tab X @tab X
197@item HuffYUV @tab X @tab X
198@item FFmpeg Video 1 @tab X @tab X @tab experimental lossless codec (fourcc: FFV1)
a590faeb 199@item Snow @tab X @tab X @tab experimental wavelet codec (fourcc: SNOW)
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200@item Asus v1 @tab X @tab X @tab fourcc: ASV1
201@item Asus v2 @tab X @tab X @tab fourcc: ASV2
202@item Creative YUV @tab @tab X @tab fourcc: CYUV
203@item Sorenson Video 1 @tab X @tab X @tab fourcc: SVQ1
204@item Sorenson Video 3 @tab @tab X @tab fourcc: SVQ3
205@item On2 VP3 @tab @tab X @tab still experimental
206@item On2 VP5 @tab @tab X @tab fourcc: VP50
207@item On2 VP6 @tab @tab X @tab fourcc: VP60,VP61,VP62
208@item Theora @tab X @tab X @tab still experimental
209@item Intel Indeo 3 @tab @tab X
210@item FLV @tab X @tab X @tab Sorenson H.263 used in Flash
211@item Flash Screen Video @tab X @tab X @tab fourcc: FSV1
212@item ATI VCR1 @tab @tab X @tab fourcc: VCR1
213@item ATI VCR2 @tab @tab X @tab fourcc: VCR2
214@item Cirrus Logic AccuPak @tab @tab X @tab fourcc: CLJR
215@item 4X Video @tab @tab X @tab Used in certain computer games.
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216@item Sony PlayStation MDEC @tab @tab X
217@item id RoQ @tab X @tab X @tab Used in Quake III, Jedi Knight 2, other computer games.
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218@item Xan/WC3 @tab @tab X @tab Used in Wing Commander III .MVE files.
219@item Interplay Video @tab @tab X @tab Used in Interplay .MVE files.
220@item Apple Animation @tab X @tab X @tab fourcc: 'rle '
221@item Apple Graphics @tab @tab X @tab fourcc: 'smc '
222@item Apple Video @tab @tab X @tab fourcc: rpza
223@item Apple QuickDraw @tab @tab X @tab fourcc: qdrw
224@item Cinepak @tab @tab X
225@item Microsoft RLE @tab @tab X
226@item Microsoft Video-1 @tab @tab X
227@item Westwood VQA @tab @tab X
831ec935 228@item id Cinematic Video @tab @tab X @tab Used in Quake II.
a590faeb 229@item planar RGB @tab @tab X @tab fourcc: 8BPS
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230@item FLIC video @tab @tab X
231@item Duck TrueMotion v1 @tab @tab X @tab fourcc: DUCK
232@item Duck TrueMotion v2 @tab @tab X @tab fourcc: TM20
233@item VMD Video @tab @tab X @tab Used in Sierra VMD files.
234@item MSZH @tab @tab X @tab Part of LCL
235@item ZLIB @tab X @tab X @tab Part of LCL, encoder experimental
236@item TechSmith Camtasia @tab @tab X @tab fourcc: TSCC
237@item IBM Ultimotion @tab @tab X @tab fourcc: ULTI
238@item Miro VideoXL @tab @tab X @tab fourcc: VIXL
239@item QPEG @tab @tab X @tab fourccs: QPEG, Q1.0, Q1.1
240@item LOCO @tab @tab X @tab
241@item Winnov WNV1 @tab @tab X @tab
a590faeb 242@item Autodesk RLE @tab @tab X @tab fourcc: AASC
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243@item Fraps FPS1 @tab @tab X @tab
244@item CamStudio @tab @tab X @tab fourcc: CSCD
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245@item American Laser Games Video @tab @tab X @tab Used in games like Mad Dog McCree.
246@item ZMBV @tab X @tab X @tab Encoder works only in PAL8.
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247@item AVS Video @tab @tab X @tab Video encoding used by the Creature Shock game.
248@item Smacker Video @tab @tab X @tab Video encoding used in Smacker.
249@item RTjpeg @tab @tab X @tab Video encoding used in NuppelVideo files.
250@item KMVC @tab @tab X @tab Codec used in Worms games.
251@item VMware Video @tab @tab X @tab Codec used in videos captured by VMware.
252@item Cin Video @tab @tab X @tab Codec used in Delphine Software games.
831ec935 253@item Tiertex Seq Video @tab @tab X @tab Codec used in DOS CD-ROM FlashBack game.
d0e1cd3d 254@item DXA Video @tab @tab X @tab Codec originally used in Feeble Files game.
fc4cbc16 255@item AVID DNxHD @tab X @tab X @tab aka SMPTE VC3
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256@item C93 Video @tab @tab X @tab Codec used in Cyberia game.
257@item THP @tab @tab X @tab Used on the Nintendo GameCube.
258@item Bethsoft VID @tab @tab X @tab Used in some games from Bethesda Softworks.
259@item Renderware TXD @tab @tab X @tab Texture dictionaries used by the Renderware Engine.
03b8e292 260@item AMV @tab @tab X @tab Used in Chinese MP3 players.
10cac9f9 261@item Mimic @tab @tab X @tab Used in MSN Messenger Webcam streams.
6ef82274 262@item Electronic Arts CMV @tab @tab X @tab Used in NHL 95 game.
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263@end multitable
264
265@code{X} means that encoding (resp. decoding) is supported.
266
267@section Audio Codecs
268
269@multitable @columnfractions .4 .1 .1 .1 .7
270@item Supported Codec @tab Encoding @tab Decoding @tab Comments
271@item MPEG audio layer 2 @tab IX @tab IX
cd15bbc9 272@item MPEG audio layer 1/3 @tab X @tab IX
d0e1cd3d 273@tab MP3 encoding is supported through the external library LAME.
0a91f4ee 274@item AC-3 @tab IX @tab IX
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275@tab liba52 is used internally for decoding.
276@item Vorbis @tab X @tab X
277@item WMA V1/V2 @tab X @tab X
278@item AAC @tab X @tab X
279@tab Supported through the external library libfaac/libfaad.
280@item Microsoft ADPCM @tab X @tab X
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281@item AMV IMA ADPCM @tab @tab X
282@tab Used in AMV files
d0e1cd3d 283@item MS IMA ADPCM @tab X @tab X
9dc92a38 284@item QT IMA ADPCM @tab X @tab X
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285@item 4X IMA ADPCM @tab @tab X
286@item G.726 ADPCM @tab X @tab X
287@item Duck DK3 IMA ADPCM @tab @tab X
288@tab Used in some Sega Saturn console games.
289@item Duck DK4 IMA ADPCM @tab @tab X
290@tab Used in some Sega Saturn console games.
291@item Westwood Studios IMA ADPCM @tab @tab X
292@tab Used in Westwood Studios games like Command and Conquer.
293@item SMJPEG IMA ADPCM @tab @tab X
294@tab Used in certain Loki game ports.
295@item CD-ROM XA ADPCM @tab @tab X
296@item CRI ADX ADPCM @tab X @tab X
297@tab Used in Sega Dreamcast games.
298@item Electronic Arts ADPCM @tab @tab X
299@tab Used in various EA titles.
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300@item MAXIS EA ADPCM @tab @tab X
301@tab Used in Sim City 3000.
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302@item Creative ADPCM @tab @tab X
303@tab 16 -> 4, 8 -> 4, 8 -> 3, 8 -> 2
304@item THP ADPCM @tab @tab X
305@tab Used on the Nintendo GameCube.
306@item RA144 @tab @tab X
307@tab Real 14400 bit/s codec
308@item RA288 @tab @tab X
309@tab Real 28800 bit/s codec
310@item RADnet @tab X @tab IX
38b5b28e 311@tab real low bitrate AC-3 codec
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312@item AMR-NB @tab X @tab X
313@tab Supported through an external library.
314@item AMR-WB @tab X @tab X
315@tab Supported through an external library.
316@item DV audio @tab @tab X
831ec935 317@item id RoQ DPCM @tab X @tab X
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318@tab Used in Quake III, Jedi Knight 2, other computer games.
319@item Interplay MVE DPCM @tab @tab X
320@tab Used in various Interplay computer games.
321@item Xan DPCM @tab @tab X
322@tab Used in Origin's Wing Commander IV AVI files.
323@item Sierra Online DPCM @tab @tab X
324@tab Used in Sierra Online game audio files.
325@item Apple MACE 3 @tab @tab X
326@item Apple MACE 6 @tab @tab X
327@item FLAC lossless audio @tab X @tab X
328@item Shorten lossless audio @tab @tab X
329@item Apple lossless audio @tab @tab X
330@tab QuickTime fourcc 'alac'
331@item FFmpeg Sonic @tab X @tab X
332@tab experimental lossy/lossless codec
333@item Qdesign QDM2 @tab @tab X
0a91f4ee 334@tab There are still some distortions.
d0e1cd3d 335@item Real COOK @tab @tab X
0a91f4ee 336@tab All versions except 5.1 are supported.
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337@item DSP Group TrueSpeech @tab @tab X
338@item True Audio (TTA) @tab @tab X
339@item Smacker Audio @tab @tab X
340@item WavPack Audio @tab @tab X
341@item Cin Audio @tab @tab X
342@tab Codec used in Delphine Software games.
343@item Intel Music Coder @tab @tab X
344@item Musepack @tab @tab X
0a91f4ee 345@tab SV7 and SV8 are supported.
831ec935 346@item DTS Coherent Audio @tab @tab X
d0e1cd3d 347@item ATRAC 3 @tab @tab X
0a91f4ee 348@item Monkey's Audio @tab @tab X @tab Only versions 3.97-3.99 are supported.
636b13c5 349@item Nellymoser ASAO @tab @tab X
d299be08 350@item 8SVX Audio @tab @tab X
f67c1f4d 351@item MLP/TrueHD @tab @tab X @tab Used in DVD-Audio and Blu-Ray discs.
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352@end multitable
353
354@code{X} means that encoding (resp. decoding) is supported.
355
356@code{I} means that an integer-only version is available, too (ensures high
357performance on systems without hardware floating point support).
358
359@chapter Platform Specific information
360
361@section BSD
362
363BSD make will not build FFmpeg, you need to install and use GNU Make
364(@file{gmake}).
365
366@section Windows
367
46a845d0 368To get help and instructions for building FFmpeg under Windows, check out
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369the FFmpeg Windows Help Forum at
370@url{http://arrozcru.no-ip.org/ffmpeg/}.
371
372@subsection Native Windows compilation
373
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374FFmpeg can be built to run natively on Windows using the MinGW tools. Install
375the current versions of MSYS and MinGW from @url{http://www.mingw.org/}. Also
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376install the coreutils package, and update to the latest MSYS make (note: not
377mingw32-make). You can find detailed installation
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378instructions in the download section and the FAQ.
379
c1989552 380Within the MSYS shell, configure and make with:
d0e1cd3d 381
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382@example
383./configure --enable-memalign-hack
384make
385make install
386@end example
d0e1cd3d 387
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388This will install @file{ffmpeg.exe} along with many other development files
389to @file{/usr/local}. You may specify another install path using the
390@code{--prefix} option in @file{configure}.
d0e1cd3d 391
c1989552 392Notes:
d0e1cd3d 393
c1989552 394@itemize
d0e1cd3d 395
751a6493 396@item Use at least bash 3.1. Older versions are known to fail on the
c1989552 397configure script.
d0e1cd3d 398
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399@item In order to compile vhooks, you must have a POSIX-compliant libdl in
400your MinGW system. Get dlfcn-win32 from
401@url{http://code.google.com/p/dlfcn-win32}.
d0e1cd3d 402
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403@item In order to compile FFplay, you must have the MinGW development library
404of SDL. Get it from @url{http://www.libsdl.org}.
405Edit the @file{bin/sdl-config} script so that it points to the correct prefix
406where SDL was installed. Verify that @file{sdl-config} can be launched from
407the MSYS command line.
d0e1cd3d 408
d0e1cd3d 409@item By using @code{./configure --enable-shared} when configuring FFmpeg,
c1989552 410you can build libavutil, libavcodec and libavformat as DLLs.
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411
412@end itemize
413
c1989552 414@subsection Microsoft Visual C++ compatibility
d0e1cd3d 415
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416As stated in the FAQ, FFmpeg will not compile under MSVC++. However, if you
417want to use the libav* libraries in your own applications, you can still
418compile those applications using MSVC++. But the libav* libraries you link
419to @emph{must} be built with MinGW. However, you will not be able to debug
420inside the libav* libraries, since MSVC++ does not recognize the debug
421symbols generated by GCC.
422We strongly recommend you to move over from MSVC++ to MinGW tools.
d0e1cd3d 423
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424This description of how to use the FFmpeg libraries with MSVC++ is based on
425Microsoft Visual C++ 2005 Express Edition. If you have a different version,
426you might have to modify the procedures slightly.
d0e1cd3d 427
c1989552 428@subsubsection Using static libraries
d0e1cd3d 429
c1989552 430Assuming you have just built and installed FFmpeg in @file{/usr/local}.
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431
432@enumerate
433
434@item Create a new console application ("File / New / Project") and then
435select "Win32 Console Application". On the appropriate page of the
436Application Wizard, uncheck the "Precompiled headers" option.
437
438@item Write the source code for your application, or, for testing, just
439copy the code from an existing sample application into the source file
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440that MSVC++ has already created for you. For example, you can copy
441@file{output_example.c} from the FFmpeg distribution.
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442
443@item Open the "Project / Properties" dialog box. In the "Configuration"
444combo box, select "All Configurations" so that the changes you make will
445affect both debug and release builds. In the tree view on the left hand
446side, select "C/C++ / General", then edit the "Additional Include
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447Directories" setting to contain the path where the FFmpeg includes were
448installed (i.e. @file{c:\msys\1.0\local\include}).
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449Do not add MinGW's include directory here, or the include files will
450conflict with MSVC's.
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451
452@item Still in the "Project / Properties" dialog box, select
453"Linker / General" from the tree view and edit the
454"Additional Library Directories" setting to contain the @file{lib}
455directory where FFmpeg was installed (i.e. @file{c:\msys\1.0\local\lib}),
456the directory where MinGW libs are installed (i.e. @file{c:\mingw\lib}),
457and the directory where MinGW's GCC libs are installed
458(i.e. @file{C:\mingw\lib\gcc\mingw32\4.2.1-sjlj}). Then select
459"Linker / Input" from the tree view, and add the files @file{libavformat.a},
460@file{libavcodec.a}, @file{libavutil.a}, @file{libmingwex.a},
461@file{libgcc.a}, and any other libraries you used (i.e. @file{libz.a})
462to the end of "Additional Dependencies".
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463
464@item Now, select "C/C++ / Code Generation" from the tree view. Select
465"Debug" in the "Configuration" combo box. Make sure that "Runtime
466Library" is set to "Multi-threaded Debug DLL". Then, select "Release" in
467the "Configuration" combo box and make sure that "Runtime Library" is
468set to "Multi-threaded DLL".
469
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470@item Click "OK" to close the "Project / Properties" dialog box.
471
472@item MSVC++ lacks some C99 header files that are fundamental for FFmpeg.
473Get msinttypes from @url{http://code.google.com/p/msinttypes/downloads/list}
474and install it in MSVC++'s include directory
475(i.e. @file{C:\Program Files\Microsoft Visual Studio 8\VC\include}).
476
477@item MSVC++ also does not understand the @code{inline} keyword used by
478FFmpeg, so you must add this line before @code{#include}ing libav*:
479@example
480#define inline _inline
481@end example
482
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483@item Build your application, everything should work.
484
485@end enumerate
486
487@subsubsection Using shared libraries
488
489This is how to create DLL and LIB files that are compatible with MSVC++:
490
491@enumerate
492
493@item Add a call to @file{vcvars32.bat} (which sets up the environment
494variables for the Visual C++ tools) as the first line of @file{msys.bat}.
495The standard location for @file{vcvars32.bat} is
496@file{C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat},
497and the standard location for @file{msys.bat} is @file{C:\msys\1.0\msys.bat}.
498If this corresponds to your setup, add the following line as the first line
499of @file{msys.bat}:
500
501@example
502call "C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat"
503@end example
504
505Alternatively, you may start the @file{Visual Studio 2005 Command Prompt},
506and run @file{c:\msys\1.0\msys.bat} from there.
507
508@item Within the MSYS shell, run @code{lib.exe}. If you get a help message
509from @file{Microsoft (R) Library Manager}, this means your environment
510variables are set up correctly, the @file{Microsoft (R) Library Manager}
511is on the path and will be used by FFmpeg to create
512MSVC++-compatible import libraries.
513
514@item Build FFmpeg with
515
516@example
517./configure --enable-shared --enable-memalign-hack
518make
519make install
520@end example
521
522Your install path (@file{/usr/local/} by default) should now have the
523necessary DLL and LIB files under the @file{bin} directory.
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524
525@end enumerate
526
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527To use those files with MSVC++, do the same as you would do with
528the static libraries, as described above. But in Step 4,
529you should only need to add the directory where the LIB files are installed
530(i.e. @file{c:\msys\usr\local\bin}). This is not a typo, the LIB files are
531installed in the @file{bin} directory. And instead of adding @file{libxx.a}
532files, you should add @file{avcodec.lib}, @file{avformat.lib}, and
533@file{avutil.lib}. There should be no need for @file{libmingwex.a},
534@file{libgcc.a}, and @file{wsock32.lib}, nor any other external library
535statically linked into the DLLs. The @file{bin} directory contains a bunch
536of DLL files, but the ones that are actually used to run your application
537are the ones with a major version number in their filenames
538(i.e. @file{avcodec-51.dll}).
539
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540@subsection Cross compilation for Windows with Linux
541
542You must use the MinGW cross compilation tools available at
543@url{http://www.mingw.org/}.
544
545Then configure FFmpeg with the following options:
546@example
547./configure --target-os=mingw32 --cross-prefix=i386-mingw32msvc-
548@end example
549(you can change the cross-prefix according to the prefix chosen for the
550MinGW tools).
551
552Then you can easily test FFmpeg with Wine
553(@url{http://www.winehq.com/}).
554
555@subsection Compilation under Cygwin
556
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557The main issue with Cygwin is that newlib, its C library, does not
558contain llrint(). However, it is possible to leverage the
559implementation in MinGW.
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560
561Just install your Cygwin with all the "Base" packages, plus the
562following "Devel" ones:
563@example
29c3d42b 564binutils, gcc-core, make, subversion, mingw-runtime
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565@end example
566
567Do not install binutils-20060709-1 (they are buggy on shared builds);
568use binutils-20050610-1 instead.
569
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570Then create a small library that just contains llrint():
571
572@example
573ar x /usr/lib/mingw/libmingwex.a llrint.o
574ar cq /usr/local/lib/libllrint.a llrint.o
575@end example
576
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577Then run
578
579@example
29c3d42b 580./configure --enable-static --disable-shared --extra-ldflags='-L /usr/local/lib' --extra-libs='-l llrint'
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581@end example
582
583to make a static build or
584
585@example
29c3d42b 586./configure --enable-shared --disable-static --extra-ldflags='-L /usr/local/lib' --extra-libs='-l llrint'
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587@end example
588
589to build shared libraries.
590
591If you want to build FFmpeg with additional libraries, download Cygwin
592"Devel" packages for Ogg and Vorbis from any Cygwin packages repository
593and/or SDL, xvid, faac, faad2 packages from Cygwin Ports,
594(@url{http://cygwinports.dotsrc.org/}).
595
596@subsection Crosscompilation for Windows under Cygwin
597
598With Cygwin you can create Windows binaries that do not need the cygwin1.dll.
599
600Just install your Cygwin as explained before, plus these additional
601"Devel" packages:
602@example
603gcc-mingw-core, mingw-runtime, mingw-zlib
604@end example
605
606and add some special flags to your configure invocation.
607
608For a static build run
609@example
610./configure --target-os=mingw32 --enable-memalign-hack --enable-static --disable-shared --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
611@end example
612
613and for a build with shared libraries
614@example
615./configure --target-os=mingw32 --enable-memalign-hack --enable-shared --disable-static --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
616@end example
617
618@section BeOS
619
5f757b85 620BeOS support is broken in mysterious ways.
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622@section OS/2
623
624For information about compiling FFmpeg on OS/2 see
625@url{http://www.edm2.com/index.php/FFmpeg}.
626
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627@chapter Developers Guide
628
629@section API
630@itemize @bullet
631@item libavcodec is the library containing the codecs (both encoding and
632decoding). Look at @file{libavcodec/apiexample.c} to see how to use it.
633
634@item libavformat is the library containing the file format handling (mux and
635demux code for several formats). Look at @file{ffplay.c} to use it in a
636player. See @file{output_example.c} to use it to generate audio or video
637streams.
638
639@end itemize
640
641@section Integrating libavcodec or libavformat in your program
642
643You can integrate all the source code of the libraries to link them
644statically to avoid any version problem. All you need is to provide a
645'config.mak' and a 'config.h' in the parent directory. See the defines
646generated by ./configure to understand what is needed.
647
648You can use libavcodec or libavformat in your commercial program, but
649@emph{any patch you make must be published}. The best way to proceed is
650to send your patches to the FFmpeg mailing list.
651
652@node Coding Rules
653@section Coding Rules
654
655FFmpeg is programmed in the ISO C90 language with a few additional
656features from ISO C99, namely:
657@itemize @bullet
658@item
659the @samp{inline} keyword;
660@item
661@samp{//} comments;
662@item
663designated struct initializers (@samp{struct s x = @{ .i = 17 @};})
664@item
665compound literals (@samp{x = (struct s) @{ 17, 23 @};})
666@end itemize
667
668These features are supported by all compilers we care about, so we will not
669accept patches to remove their use unless they absolutely do not impair
670clarity and performance.
671
672All code must compile with GCC 2.95 and GCC 3.3. Currently, FFmpeg also
673compiles with several other compilers, such as the Compaq ccc compiler
674or Sun Studio 9, and we would like to keep it that way unless it would
675be exceedingly involved. To ensure compatibility, please do not use any
676additional C99 features or GCC extensions. Especially watch out for:
677@itemize @bullet
678@item
679mixing statements and declarations;
680@item
681@samp{long long} (use @samp{int64_t} instead);
682@item
683@samp{__attribute__} not protected by @samp{#ifdef __GNUC__} or similar;
684@item
685GCC statement expressions (@samp{(x = (@{ int y = 4; y; @})}).
686@end itemize
687
688Indent size is 4.
689The presentation is the one specified by 'indent -i4 -kr -nut'.
690The TAB character is forbidden outside of Makefiles as is any
691form of trailing whitespace. Commits containing either will be
692rejected by the Subversion repository.
693
694The main priority in FFmpeg is simplicity and small code size in order to
695minimize the bug count.
696
697Comments: Use the JavaDoc/Doxygen
698format (see examples below) so that code documentation
699can be generated automatically. All nontrivial functions should have a comment
700above them explaining what the function does, even if it is just one sentence.
701All structures and their member variables should be documented, too.
702@example
703/**
704 * @@file mpeg.c
705 * MPEG codec.
706 * @@author ...
707 */
708
709/**
710 * Summary sentence.
711 * more text ...
712 * ...
713 */
714typedef struct Foobar@{
715 int var1; /**< var1 description */
716 int var2; ///< var2 description
717 /** var3 description */
718 int var3;
719@} Foobar;
720
721/**
722 * Summary sentence.
723 * more text ...
724 * ...
725 * @@param my_parameter description of my_parameter
726 * @@return return value description
727 */
728int myfunc(int my_parameter)
729...
730@end example
731
732fprintf and printf are forbidden in libavformat and libavcodec,
733please use av_log() instead.
734
735Casts should be used only when necessary. Unneeded parentheses
736should also be avoided if they don't make the code easier to understand.
737
738@section Development Policy
739
740@enumerate
741@item
742 Contributions should be licensed under the LGPL 2.1, including an
743 "or any later version" clause, or the MIT license. GPL 2 including
744 an "or any later version" clause is also acceptable, but LGPL is
745 preferred.
746@item
747 You must not commit code which breaks FFmpeg! (Meaning unfinished but
748 enabled code which breaks compilation or compiles but does not work or
749 breaks the regression tests)
750 You can commit unfinished stuff (for testing etc), but it must be disabled
751 (#ifdef etc) by default so it does not interfere with other developers'
752 work.
753@item
754 You do not have to over-test things. If it works for you, and you think it
755 should work for others, then commit. If your code has problems
756 (portability, triggers compiler bugs, unusual environment etc) they will be
757 reported and eventually fixed.
758@item
759 Do not commit unrelated changes together, split them into self-contained
760 pieces. Also do not forget that if part B depends on part A, but A does not
761 depend on B, then A can and should be committed first and separate from B.
762 Keeping changes well split into self-contained parts makes reviewing and
763 understanding them on the commit log mailing list easier. This also helps
764 in case of debugging later on.
765 Also if you have doubts about splitting or not splitting, do not hesitate to
766 ask/discuss it on the developer mailing list.
767@item
768 Do not change behavior of the program (renaming options etc) without
769 first discussing it on the ffmpeg-devel mailing list. Do not remove
770 functionality from the code. Just improve!
771
772 Note: Redundant code can be removed.
773@item
774 Do not commit changes to the build system (Makefiles, configure script)
775 which change behavior, defaults etc, without asking first. The same
776 applies to compiler warning fixes, trivial looking fixes and to code
777 maintained by other developers. We usually have a reason for doing things
778 the way we do. Send your changes as patches to the ffmpeg-devel mailing
779 list, and if the code maintainers say OK, you may commit. This does not
780 apply to files you wrote and/or maintain.
781@item
782 We refuse source indentation and other cosmetic changes if they are mixed
783 with functional changes, such commits will be rejected and removed. Every
784 developer has his own indentation style, you should not change it. Of course
785 if you (re)write something, you can use your own style, even though we would
786 prefer if the indentation throughout FFmpeg was consistent (Many projects
787 force a given indentation style - we do not.). If you really need to make
788 indentation changes (try to avoid this), separate them strictly from real
789 changes.
790
791 NOTE: If you had to put if()@{ .. @} over a large (> 5 lines) chunk of code,
792 then either do NOT change the indentation of the inner part within (do not
793 move it to the right)! or do so in a separate commit
794@item
795 Always fill out the commit log message. Describe in a few lines what you
796 changed and why. You can refer to mailing list postings if you fix a
797 particular bug. Comments such as "fixed!" or "Changed it." are unacceptable.
798@item
799 If you apply a patch by someone else, include the name and email address in
800 the log message. Since the ffmpeg-cvslog mailing list is publicly
801 archived you should add some SPAM protection to the email address. Send an
802 answer to ffmpeg-devel (or wherever you got the patch from) saying that
803 you applied the patch.
804@item
805 When applying patches that have been discussed (at length) on the mailing
806 list, reference the thread in the log message.
807@item
808 Do NOT commit to code actively maintained by others without permission.
809 Send a patch to ffmpeg-devel instead. If no one answers within a reasonable
810 timeframe (12h for build failures and security fixes, 3 days small changes,
811 1 week for big patches) then commit your patch if you think it is OK.
812 Also note, the maintainer can simply ask for more time to review!
813@item
814 Subscribe to the ffmpeg-cvslog mailing list. The diffs of all commits
815 are sent there and reviewed by all the other developers. Bugs and possible
816 improvements or general questions regarding commits are discussed there. We
817 expect you to react if problems with your code are uncovered.
818@item
819 Update the documentation if you change behavior or add features. If you are
820 unsure how best to do this, send a patch to ffmpeg-devel, the documentation
821 maintainer(s) will review and commit your stuff.
822@item
823 Try to keep important discussions and requests (also) on the public
824 developer mailing list, so that all developers can benefit from them.
825@item
826 Never write to unallocated memory, never write over the end of arrays,
827 always check values read from some untrusted source before using them
828 as array index or other risky things.
829@item
830 Remember to check if you need to bump versions for the specific libav
831 parts (libavutil, libavcodec, libavformat) you are changing. You need
832 to change the version integer and the version string.
833 Incrementing the first component means no backward compatibility to
834 previous versions (e.g. removal of a function from the public API).
835 Incrementing the second component means backward compatible change
836 (e.g. addition of a function to the public API).
837 Incrementing the third component means a noteworthy binary compatible
838 change (e.g. encoder bug fix that matters for the decoder).
839@item
840 If you add a new codec, remember to update the changelog, add it to
841 the supported codecs table in the documentation and bump the second
842 component of the @file{libavcodec} version number appropriately. If
74a926ff 843 it has a fourcc, add it to @file{libavformat/riff.c}, even if it
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844 is only a decoder.
845@item
53407b64 846 Compiler warnings indicate potential bugs or code with bad style. If a type of
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847 warning always points to correct and clean code, that warning should
848 be disabled, not the code changed.
849 Thus the remaining warnings can either be bugs or correct code.
beaa4a91 850 If it is a bug, the bug has to be fixed. If it is not, the code should
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851 be changed to not generate a warning unless that causes a slowdown
852 or obfuscates the code.
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853@item
854 If you add a new file, give it a proper license header. Do not copy and
855 paste it from a random place, use an existing file as template.
856@end enumerate
857
858We think our rules are not too hard. If you have comments, contact us.
859
860Note, these rules are mostly borrowed from the MPlayer project.
861
862@section Submitting patches
863
864First, (@pxref{Coding Rules}) above if you did not yet.
865
866When you submit your patch, try to send a unified diff (diff '-up'
867option). We cannot read other diffs :-)
868
869Also please do not submit a patch which contains several unrelated changes.
870Split it into separate, self-contained pieces. This does not mean splitting
871file by file. Instead, make the patch as small as possible while still
872keeping it as a logical unit that contains an individual change, even
873if it spans multiple files. This makes reviewing your patches much easier
874for us and greatly increases your chances of getting your patch applied.
875
876Run the regression tests before submitting a patch so that you can
877verify that there are no big problems.
878
879Patches should be posted as base64 encoded attachments (or any other
880encoding which ensures that the patch will not be trashed during
881transmission) to the ffmpeg-devel mailing list, see
882@url{http://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel}
883
884It also helps quite a bit if you tell us what the patch does (for example
885'replaces lrint by lrintf'), and why (for example '*BSD isn't C99 compliant
886and has no lrint()')
887
888Also please if you send several patches, send each patch as a separate mail,
889do not attach several unrelated patches to the same mail.
890
891@section patch submission checklist
892
893@enumerate
894@item
895 Do the regression tests pass with the patch applied?
896@item
897 Is the patch a unified diff?
898@item
899 Is the patch against latest FFmpeg SVN?
900@item
901 Are you subscribed to ffmpeg-dev?
902 (the list is subscribers only due to spam)
903@item
904 Have you checked that the changes are minimal, so that the same cannot be
905 achieved with a smaller patch and/or simpler final code?
906@item
907 If the change is to speed critical code, did you benchmark it?
908@item
909 If you did any benchmarks, did you provide them in the mail?
910@item
911 Have you checked that the patch does not introduce buffer overflows or
912 other security issues?
913@item
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914 If you add a new demuxer or decoder, have you checked that it does not
915 crash with damaged input (see tools/trasher)?
916@item
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917 Is the patch created from the root of the source tree, so it can be
918 applied with @code{patch -p0}?
919@item
920 Does the patch not mix functional and cosmetic changes?
921@item
922 Did you add tabs or trailing whitespace to the code? Both are forbidden.
923@item
924 Is the patch attached to the email you send?
925@item
926 Is the mime type of the patch correct? It should be text/x-diff or
927 text/x-patch or at least text/plain and not application/octet-stream.
928@item
929 If the patch fixes a bug, did you provide a verbose analysis of the bug?
930@item
931 If the patch fixes a bug, did you provide enough information, including
932 a sample, so the bug can be reproduced and the fix can be verified?
933 Note please do not attach samples >100k to mails but rather provide a
934 URL, you can upload to ftp://upload.mplayerhq.hu
935@item
936 Did you provide a verbose summary about what the patch does change?
937@item
938 Did you provide a verbose explanation why it changes things like it does?
939@item
940 Did you provide a verbose summary of the user visible advantages and
941 disadvantages if the patch is applied?
942@item
943 Did you provide an example so we can verify the new feature added by the
944 patch easily?
945@item
946 If you added a new file, did you insert a license header? It should be
947 taken from FFmpeg, not randomly copied and pasted from somewhere else.
948@item
949 You should maintain alphabetical order in alphabetically ordered lists as
950 long as doing so does not break API/ABI compatibility.
951@item
952 Lines with similar content should be aligned vertically when doing so
953 improves readability.
954@item
955 Did you provide a suggestion for a clear commit log message?
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956@item
957 Did you test your decoder or demuxer against damaged data? If no, see
958 tools/trasher and the noise bitstream filter. Your decoder or demuxer
fe74278f 959 should not crash or end in a (near) infinite loop when fed damaged data.
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960@end enumerate
961
962@section Patch review process
963
964All patches posted to ffmpeg-devel will be reviewed, unless they contain a
965clear note that the patch is not for SVN.
966Reviews and comments will be posted as replies to the patch on the
967mailing list. The patch submitter then has to take care of every comment,
968that can be by resubmitting a changed patch or by discussion. Resubmitted
969patches will themselves be reviewed like any other patch. If at some point
970a patch passes review with no comments then it is approved, that can for
971simple and small patches happen immediately while large patches will generally
972have to be changed and reviewed many times before they are approved.
973After a patch is approved it will be committed to the repository.
974
975We will review all submitted patches, but sometimes we are quite busy so
976especially for large patches this can take several weeks.
977
978When resubmitting patches, please do not make any significant changes
979not related to the comments received during review. Such patches will
980be rejected. Instead, submit significant changes or new features as
981separate patches.
982
983@section Regression tests
984
985Before submitting a patch (or committing to the repository), you should at least
986test that you did not break anything.
987
988The regression tests build a synthetic video stream and a synthetic
989audio stream. These are then encoded and decoded with all codecs or
990formats. The CRC (or MD5) of each generated file is recorded in a
991result file. A 'diff' is launched to compare the reference results and
992the result file.
993
994The regression tests then go on to test the FFserver code with a
995limited set of streams. It is important that this step runs correctly
996as well.
997
998Run 'make test' to test all the codecs and formats.
999
1000Run 'make fulltest' to test all the codecs, formats and FFserver.
1001
1002[Of course, some patches may change the results of the regression tests. In
1003this case, the reference results of the regression tests shall be modified
1004accordingly].
1005
1006@bye