Add IFF demuxer and 8SVX audio decoder to changelog and documentation.
[libav.git] / doc / general.texi
CommitLineData
d0e1cd3d
DB
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
50e4d833
DB
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.
d0e1cd3d
DB
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
68e7d442
DB
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
d0e1cd3d
DB
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
d0e1cd3d
DB
56@tab Only embedded audio is decoded.
57@item FLV @tab X @tab X
58@tab Macromedia Flash video files
59@item Real Audio and Video @tab X @tab X
60@item Raw AC3 @tab X @tab X
61@item Raw MJPEG @tab X @tab X
62@item Raw MPEG video @tab X @tab X
63@item Raw PCM8/16 bits, mulaw/Alaw@tab X @tab X
64@item Raw CRI ADX audio @tab X @tab X
65@item Raw Shorten audio @tab @tab X
66@item SUN AU format @tab X @tab X
67@item NUT @tab X @tab X @tab NUT Open Container Format
68@item QuickTime @tab X @tab X
69@item MPEG-4 @tab X @tab X
70@tab MPEG-4 is a variant of QuickTime.
71@item Raw MPEG4 video @tab X @tab X
72@item DV @tab X @tab X
73@item 4xm @tab @tab X
74@tab 4X Technologies format, used in some games.
75@item Playstation STR @tab @tab X
76@item Id RoQ @tab X @tab X
77@tab Used in Quake III, Jedi Knight 2, other computer games.
78@item Interplay MVE @tab @tab X
79@tab Format used in various Interplay computer games.
80@item WC3 Movie @tab @tab X
81@tab Multimedia format used in Origin's Wing Commander III computer game.
82@item Sega FILM/CPK @tab @tab X
83@tab Used in many Sega Saturn console games.
84@item Westwood Studios VQA/AUD @tab @tab X
85@tab Multimedia formats used in Westwood Studios games.
86@item Id Cinematic (.cin) @tab @tab X
87@tab Used in Quake II.
88@item FLIC format @tab @tab X
89@tab .fli/.flc files
90@item Sierra VMD @tab @tab X
91@tab Used in Sierra CD-ROM games.
92@item Sierra Online @tab @tab X
93@tab .sol files used in Sierra Online games.
e09f7d61 94@item Matroska @tab X @tab X
d0e1cd3d
DB
95@item Electronic Arts Multimedia @tab @tab X
96@tab Used in various EA games; files have extensions like WVE and UV2.
97@item Nullsoft Video (NSV) format @tab @tab X
98@item ADTS AAC audio @tab X @tab X
99@item Creative VOC @tab X @tab X @tab Created for the Sound Blaster Pro.
100@item American Laser Games MM @tab @tab X
101@tab Multimedia format used in games like Mad Dog McCree
102@item AVS @tab @tab X
103@tab Multimedia format used by the Creature Shock game.
104@item Smacker @tab @tab X
105@tab Multimedia format used by many games.
106@item GXF @tab X @tab X
107@tab General eXchange Format SMPTE 360M, used by Thomson Grass Valley playout servers.
108@item CIN @tab @tab X
109@tab Multimedia format used by Delphine Software games.
110@item MXF @tab @tab X
111@tab Material eXchange Format SMPTE 377M, used by D-Cinema, broadcast industry.
112@item SEQ @tab @tab X
113@tab Tiertex .seq files used in the DOS CDROM version of the game Flashback.
114@item DXA @tab @tab X
115@tab This format is used in non-Windows version of Feeble Files game and
116different game cutscenes repacked for use with ScummVM.
117@item THP @tab @tab X
118@tab Used on the Nintendo GameCube.
119@item C93 @tab @tab X
120@tab Used in the game Cyberia from Interplay.
121@item Bethsoft VID @tab @tab X
122@tab Used in some games from Bethesda Softworks.
123@item CRYO APC @tab @tab X
124@tab Audio format used in some games by CRYO Interactive Entertainment.
bf4a1f17 125@item Monkey's Audio @tab @tab X
66f7679c
KS
126@item SIFF @tab @tab X
127@tab Audio and video format used in some games by Beam Software
d1928ac1
IP
128@item LMLM4 @tab @tab X
129@tab Used by Linux Media Labs MPEG-4 PCI boards
130@item PVA @tab @tab X
131@tab Used by TechnoTrend DVB PCI boards
10cac9f9
RP
132@item MSN TCP Webcam @tab @tab X
133@tab Used by MSN Messenger Webcam streams.
86b3cf7c
SS
134@item RL2 @tab @tab X
135@tab Audio and video format used in some games by Entertainment Software Partners
d299be08
JM
136@item IFF @tab @tab X
137@tab Interchange File Format
d0e1cd3d
DB
138@end multitable
139
140@code{X} means that encoding (resp. decoding) is supported.
141
142@section Image Formats
143
144FFmpeg can read and write images for each frame of a video sequence. The
145following image formats are supported:
146
147@multitable @columnfractions .4 .1 .1 .4
148@item Supported Image Format @tab Encoding @tab Decoding @tab Comments
149@item PGM, PPM @tab X @tab X
150@item PAM @tab X @tab X @tab PAM is a PNM extension with alpha support.
151@item PGMYUV @tab X @tab X @tab PGM with U and V components in YUV 4:2:0
152@item JPEG @tab X @tab X @tab Progressive JPEG is not supported.
153@item .Y.U.V @tab X @tab X @tab one raw file per component
154@item animated GIF @tab X @tab X @tab Only uncompressed GIFs are generated.
155@item PNG @tab X @tab X @tab 2 bit and 4 bit/pixel not supported yet.
156@item Targa @tab @tab X @tab Targa (.TGA) image format.
157@item TIFF @tab X @tab X @tab YUV, JPEG and some extension is not supported yet.
158@item SGI @tab X @tab X @tab SGI RGB image format
159@item PTX @tab @tab X @tab V.Flash PTX format
d1928ac1
IP
160@item RAS @tab @tab X @tab Sun Rasterfile
161@item PCX @tab @tab X @tab PC Paintbrush
d0e1cd3d
DB
162@end multitable
163
164@code{X} means that encoding (resp. decoding) is supported.
165
166@section Video Codecs
167
168@multitable @columnfractions .4 .1 .1 .4
169@item Supported Codec @tab Encoding @tab Decoding @tab Comments
170@item MPEG-1 video @tab X @tab X
171@item MPEG-2 video @tab X @tab X
172@item MPEG-4 @tab X @tab X
173@item MSMPEG4 V1 @tab X @tab X
174@item MSMPEG4 V2 @tab X @tab X
175@item MSMPEG4 V3 @tab X @tab X
176@item WMV7 @tab X @tab X
177@item WMV8 @tab X @tab X @tab not completely working
178@item WMV9 @tab @tab X @tab not completely working
179@item VC1 @tab @tab X
180@item H.261 @tab X @tab X
181@item H.263(+) @tab X @tab X @tab also known as RealVideo 1.0
182@item H.264 @tab @tab X
183@item RealVideo 1.0 @tab X @tab X
184@item RealVideo 2.0 @tab X @tab X
185@item MJPEG @tab X @tab X
186@item lossless MJPEG @tab X @tab X
187@item JPEG-LS @tab X @tab X @tab fourcc: MJLS, lossless and near-lossless is supported
188@item Apple MJPEG-B @tab @tab X
189@item Sunplus MJPEG @tab @tab X @tab fourcc: SP5X
190@item DV @tab X @tab X
191@item HuffYUV @tab X @tab X
192@item FFmpeg Video 1 @tab X @tab X @tab experimental lossless codec (fourcc: FFV1)
193@item FFmpeg Snow @tab X @tab X @tab experimental wavelet codec (fourcc: SNOW)
194@item Asus v1 @tab X @tab X @tab fourcc: ASV1
195@item Asus v2 @tab X @tab X @tab fourcc: ASV2
196@item Creative YUV @tab @tab X @tab fourcc: CYUV
197@item Sorenson Video 1 @tab X @tab X @tab fourcc: SVQ1
198@item Sorenson Video 3 @tab @tab X @tab fourcc: SVQ3
199@item On2 VP3 @tab @tab X @tab still experimental
200@item On2 VP5 @tab @tab X @tab fourcc: VP50
201@item On2 VP6 @tab @tab X @tab fourcc: VP60,VP61,VP62
202@item Theora @tab X @tab X @tab still experimental
203@item Intel Indeo 3 @tab @tab X
204@item FLV @tab X @tab X @tab Sorenson H.263 used in Flash
205@item Flash Screen Video @tab X @tab X @tab fourcc: FSV1
206@item ATI VCR1 @tab @tab X @tab fourcc: VCR1
207@item ATI VCR2 @tab @tab X @tab fourcc: VCR2
208@item Cirrus Logic AccuPak @tab @tab X @tab fourcc: CLJR
209@item 4X Video @tab @tab X @tab Used in certain computer games.
210@item Sony Playstation MDEC @tab @tab X
211@item Id RoQ @tab X @tab X @tab Used in Quake III, Jedi Knight 2, other computer games.
212@item Xan/WC3 @tab @tab X @tab Used in Wing Commander III .MVE files.
213@item Interplay Video @tab @tab X @tab Used in Interplay .MVE files.
214@item Apple Animation @tab X @tab X @tab fourcc: 'rle '
215@item Apple Graphics @tab @tab X @tab fourcc: 'smc '
216@item Apple Video @tab @tab X @tab fourcc: rpza
217@item Apple QuickDraw @tab @tab X @tab fourcc: qdrw
218@item Cinepak @tab @tab X
219@item Microsoft RLE @tab @tab X
220@item Microsoft Video-1 @tab @tab X
221@item Westwood VQA @tab @tab X
222@item Id Cinematic Video @tab @tab X @tab Used in Quake II.
223@item Planar RGB @tab @tab X @tab fourcc: 8BPS
224@item FLIC video @tab @tab X
225@item Duck TrueMotion v1 @tab @tab X @tab fourcc: DUCK
226@item Duck TrueMotion v2 @tab @tab X @tab fourcc: TM20
227@item VMD Video @tab @tab X @tab Used in Sierra VMD files.
228@item MSZH @tab @tab X @tab Part of LCL
229@item ZLIB @tab X @tab X @tab Part of LCL, encoder experimental
230@item TechSmith Camtasia @tab @tab X @tab fourcc: TSCC
231@item IBM Ultimotion @tab @tab X @tab fourcc: ULTI
232@item Miro VideoXL @tab @tab X @tab fourcc: VIXL
233@item QPEG @tab @tab X @tab fourccs: QPEG, Q1.0, Q1.1
234@item LOCO @tab @tab X @tab
235@item Winnov WNV1 @tab @tab X @tab
236@item Autodesk Animator Studio Codec @tab @tab X @tab fourcc: AASC
237@item Fraps FPS1 @tab @tab X @tab
238@item CamStudio @tab @tab X @tab fourcc: CSCD
239@item American Laser Games Video @tab @tab X @tab Used in games like Mad Dog McCree
240@item ZMBV @tab X @tab X @tab Encoder works only on PAL8
241@item AVS Video @tab @tab X @tab Video encoding used by the Creature Shock game.
242@item Smacker Video @tab @tab X @tab Video encoding used in Smacker.
243@item RTjpeg @tab @tab X @tab Video encoding used in NuppelVideo files.
244@item KMVC @tab @tab X @tab Codec used in Worms games.
245@item VMware Video @tab @tab X @tab Codec used in videos captured by VMware.
246@item Cin Video @tab @tab X @tab Codec used in Delphine Software games.
247@item Tiertex Seq Video @tab @tab X @tab Codec used in DOS CDROM FlashBack game.
248@item DXA Video @tab @tab X @tab Codec originally used in Feeble Files game.
fc4cbc16 249@item AVID DNxHD @tab X @tab X @tab aka SMPTE VC3
d0e1cd3d
DB
250@item C93 Video @tab @tab X @tab Codec used in Cyberia game.
251@item THP @tab @tab X @tab Used on the Nintendo GameCube.
252@item Bethsoft VID @tab @tab X @tab Used in some games from Bethesda Softworks.
253@item Renderware TXD @tab @tab X @tab Texture dictionaries used by the Renderware Engine.
03b8e292 254@item AMV @tab @tab X @tab Used in Chinese MP3 players.
10cac9f9 255@item Mimic @tab @tab X @tab Used in MSN Messenger Webcam streams.
d0e1cd3d
DB
256@end multitable
257
258@code{X} means that encoding (resp. decoding) is supported.
259
260@section Audio Codecs
261
262@multitable @columnfractions .4 .1 .1 .1 .7
263@item Supported Codec @tab Encoding @tab Decoding @tab Comments
264@item MPEG audio layer 2 @tab IX @tab IX
cd15bbc9 265@item MPEG audio layer 1/3 @tab X @tab IX
d0e1cd3d
DB
266@tab MP3 encoding is supported through the external library LAME.
267@item AC3 @tab IX @tab IX
268@tab liba52 is used internally for decoding.
269@item Vorbis @tab X @tab X
270@item WMA V1/V2 @tab X @tab X
271@item AAC @tab X @tab X
272@tab Supported through the external library libfaac/libfaad.
273@item Microsoft ADPCM @tab X @tab X
a1748c67
VS
274@item AMV IMA ADPCM @tab @tab X
275@tab Used in AMV files
d0e1cd3d 276@item MS IMA ADPCM @tab X @tab X
9dc92a38 277@item QT IMA ADPCM @tab X @tab X
d0e1cd3d
DB
278@item 4X IMA ADPCM @tab @tab X
279@item G.726 ADPCM @tab X @tab X
280@item Duck DK3 IMA ADPCM @tab @tab X
281@tab Used in some Sega Saturn console games.
282@item Duck DK4 IMA ADPCM @tab @tab X
283@tab Used in some Sega Saturn console games.
284@item Westwood Studios IMA ADPCM @tab @tab X
285@tab Used in Westwood Studios games like Command and Conquer.
286@item SMJPEG IMA ADPCM @tab @tab X
287@tab Used in certain Loki game ports.
288@item CD-ROM XA ADPCM @tab @tab X
289@item CRI ADX ADPCM @tab X @tab X
290@tab Used in Sega Dreamcast games.
291@item Electronic Arts ADPCM @tab @tab X
292@tab Used in various EA titles.
293@item Creative ADPCM @tab @tab X
294@tab 16 -> 4, 8 -> 4, 8 -> 3, 8 -> 2
295@item THP ADPCM @tab @tab X
296@tab Used on the Nintendo GameCube.
297@item RA144 @tab @tab X
298@tab Real 14400 bit/s codec
299@item RA288 @tab @tab X
300@tab Real 28800 bit/s codec
301@item RADnet @tab X @tab IX
302@tab Real low bitrate AC3 codec, liba52 is used for decoding.
303@item AMR-NB @tab X @tab X
304@tab Supported through an external library.
305@item AMR-WB @tab X @tab X
306@tab Supported through an external library.
307@item DV audio @tab @tab X
308@item Id RoQ DPCM @tab X @tab X
309@tab Used in Quake III, Jedi Knight 2, other computer games.
310@item Interplay MVE DPCM @tab @tab X
311@tab Used in various Interplay computer games.
312@item Xan DPCM @tab @tab X
313@tab Used in Origin's Wing Commander IV AVI files.
314@item Sierra Online DPCM @tab @tab X
315@tab Used in Sierra Online game audio files.
316@item Apple MACE 3 @tab @tab X
317@item Apple MACE 6 @tab @tab X
318@item FLAC lossless audio @tab X @tab X
319@item Shorten lossless audio @tab @tab X
320@item Apple lossless audio @tab @tab X
321@tab QuickTime fourcc 'alac'
322@item FFmpeg Sonic @tab X @tab X
323@tab experimental lossy/lossless codec
324@item Qdesign QDM2 @tab @tab X
325@tab there are still some distortions
326@item Real COOK @tab @tab X
327@tab All versions except 5.1 are supported
328@item DSP Group TrueSpeech @tab @tab X
329@item True Audio (TTA) @tab @tab X
330@item Smacker Audio @tab @tab X
331@item WavPack Audio @tab @tab X
332@item Cin Audio @tab @tab X
333@tab Codec used in Delphine Software games.
334@item Intel Music Coder @tab @tab X
335@item Musepack @tab @tab X
12877faf 336@tab SV7 and SV8 are supported
d0e1cd3d
DB
337@item DT$ Coherent Audio @tab @tab X
338@item ATRAC 3 @tab @tab X
bf4a1f17 339@item Monkey's Audio @tab @tab X @tab Only versions 3.97-3.99 are supported
636b13c5 340@item Nellymoser ASAO @tab @tab X
d299be08 341@item 8SVX Audio @tab @tab X
d0e1cd3d
DB
342@end multitable
343
344@code{X} means that encoding (resp. decoding) is supported.
345
346@code{I} means that an integer-only version is available, too (ensures high
347performance on systems without hardware floating point support).
348
349@chapter Platform Specific information
350
351@section BSD
352
353BSD make will not build FFmpeg, you need to install and use GNU Make
354(@file{gmake}).
355
356@section Windows
357
46a845d0 358To get help and instructions for building FFmpeg under Windows, check out
d0e1cd3d
DB
359the FFmpeg Windows Help Forum at
360@url{http://arrozcru.no-ip.org/ffmpeg/}.
361
362@subsection Native Windows compilation
363
c1989552
RP
364FFmpeg can be built to run natively on Windows using the MinGW tools. Install
365the current versions of MSYS and MinGW from @url{http://www.mingw.org/}. Also
366install the coreutils package. You can find detailed installation
d0e1cd3d
DB
367instructions in the download section and the FAQ.
368
c1989552 369Within the MSYS shell, configure and make with:
d0e1cd3d 370
c1989552
RP
371@example
372./configure --enable-memalign-hack
373make
374make install
375@end example
d0e1cd3d 376
c1989552
RP
377This will install @file{ffmpeg.exe} along with many other development files
378to @file{/usr/local}. You may specify another install path using the
379@code{--prefix} option in @file{configure}.
d0e1cd3d 380
c1989552 381Notes:
d0e1cd3d 382
c1989552 383@itemize
d0e1cd3d 384
751a6493 385@item Use at least bash 3.1. Older versions are known to fail on the
c1989552 386configure script.
d0e1cd3d 387
c1989552
RP
388@item In order to compile vhooks, you must have a POSIX-compliant libdl in
389your MinGW system. Get dlfcn-win32 from
390@url{http://code.google.com/p/dlfcn-win32}.
d0e1cd3d 391
c1989552
RP
392@item In order to compile FFplay, you must have the MinGW development library
393of SDL. Get it from @url{http://www.libsdl.org}.
394Edit the @file{bin/sdl-config} script so that it points to the correct prefix
395where SDL was installed. Verify that @file{sdl-config} can be launched from
396the MSYS command line.
d0e1cd3d 397
c1989552
RP
398@item The target @code{make wininstaller} can be used to create a
399Nullsoft-based Windows installer for FFmpeg and FFplay. @file{SDL.dll}
d0e1cd3d
DB
400must be copied to the FFmpeg directory in order to build the
401installer.
402
403@item By using @code{./configure --enable-shared} when configuring FFmpeg,
c1989552 404you can build libavutil, libavcodec and libavformat as DLLs.
d0e1cd3d
DB
405
406@end itemize
407
c1989552 408@subsection Microsoft Visual C++ compatibility
d0e1cd3d 409
c1989552
RP
410As stated in the FAQ, FFmpeg will not compile under MSVC++. However, if you
411want to use the libav* libraries in your own applications, you can still
412compile those applications using MSVC++. But the libav* libraries you link
413to @emph{must} be built with MinGW. However, you will not be able to debug
414inside the libav* libraries, since MSVC++ does not recognize the debug
415symbols generated by GCC.
416We strongly recommend you to move over from MSVC++ to MinGW tools.
d0e1cd3d 417
c1989552
RP
418This description of how to use the FFmpeg libraries with MSVC++ is based on
419Microsoft Visual C++ 2005 Express Edition. If you have a different version,
420you might have to modify the procedures slightly.
d0e1cd3d 421
c1989552 422@subsubsection Using static libraries
d0e1cd3d 423
c1989552 424Assuming you have just built and installed FFmpeg in @file{/usr/local}.
d0e1cd3d
DB
425
426@enumerate
427
428@item Create a new console application ("File / New / Project") and then
429select "Win32 Console Application". On the appropriate page of the
430Application Wizard, uncheck the "Precompiled headers" option.
431
432@item Write the source code for your application, or, for testing, just
433copy the code from an existing sample application into the source file
c1989552
RP
434that MSVC++ has already created for you. For example, you can copy
435@file{output_example.c} from the FFmpeg distribution.
d0e1cd3d
DB
436
437@item Open the "Project / Properties" dialog box. In the "Configuration"
438combo box, select "All Configurations" so that the changes you make will
439affect both debug and release builds. In the tree view on the left hand
440side, select "C/C++ / General", then edit the "Additional Include
c1989552
RP
441Directories" setting to contain the path where the FFmpeg includes were
442installed (i.e. @file{c:\msys\1.0\local\include}).
443
444@item Still in the "Project / Properties" dialog box, select
445"Linker / General" from the tree view and edit the
446"Additional Library Directories" setting to contain the @file{lib}
447directory where FFmpeg was installed (i.e. @file{c:\msys\1.0\local\lib}),
448the directory where MinGW libs are installed (i.e. @file{c:\mingw\lib}),
449and the directory where MinGW's GCC libs are installed
450(i.e. @file{C:\mingw\lib\gcc\mingw32\4.2.1-sjlj}). Then select
451"Linker / Input" from the tree view, and add the files @file{libavformat.a},
452@file{libavcodec.a}, @file{libavutil.a}, @file{libmingwex.a},
453@file{libgcc.a}, and any other libraries you used (i.e. @file{libz.a})
454to the end of "Additional Dependencies".
d0e1cd3d
DB
455
456@item Now, select "C/C++ / Code Generation" from the tree view. Select
457"Debug" in the "Configuration" combo box. Make sure that "Runtime
458Library" is set to "Multi-threaded Debug DLL". Then, select "Release" in
459the "Configuration" combo box and make sure that "Runtime Library" is
460set to "Multi-threaded DLL".
461
c1989552
RP
462@item Click "OK" to close the "Project / Properties" dialog box.
463
464@item MSVC++ lacks some C99 header files that are fundamental for FFmpeg.
465Get msinttypes from @url{http://code.google.com/p/msinttypes/downloads/list}
466and install it in MSVC++'s include directory
467(i.e. @file{C:\Program Files\Microsoft Visual Studio 8\VC\include}).
468
469@item MSVC++ also does not understand the @code{inline} keyword used by
470FFmpeg, so you must add this line before @code{#include}ing libav*:
471@example
472#define inline _inline
473@end example
474
475@item If you used @file{output_example.c} as your sample application,
476you will have to edit the @code{#include}s to point to the files which
477are under the @file{ffmpeg} directory (i.e. @code{<ffmpeg/avformat.h>}).
478
479@item Build your application, everything should work.
480
481@end enumerate
482
483@subsubsection Using shared libraries
484
485This is how to create DLL and LIB files that are compatible with MSVC++:
486
487@enumerate
488
489@item Add a call to @file{vcvars32.bat} (which sets up the environment
490variables for the Visual C++ tools) as the first line of @file{msys.bat}.
491The standard location for @file{vcvars32.bat} is
492@file{C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat},
493and the standard location for @file{msys.bat} is @file{C:\msys\1.0\msys.bat}.
494If this corresponds to your setup, add the following line as the first line
495of @file{msys.bat}:
496
497@example
498call "C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat"
499@end example
500
501Alternatively, you may start the @file{Visual Studio 2005 Command Prompt},
502and run @file{c:\msys\1.0\msys.bat} from there.
503
504@item Within the MSYS shell, run @code{lib.exe}. If you get a help message
505from @file{Microsoft (R) Library Manager}, this means your environment
506variables are set up correctly, the @file{Microsoft (R) Library Manager}
507is on the path and will be used by FFmpeg to create
508MSVC++-compatible import libraries.
509
510@item Build FFmpeg with
511
512@example
513./configure --enable-shared --enable-memalign-hack
514make
515make install
516@end example
517
518Your install path (@file{/usr/local/} by default) should now have the
519necessary DLL and LIB files under the @file{bin} directory.
d0e1cd3d
DB
520
521@end enumerate
522
c1989552
RP
523To use those files with MSVC++, do the same as you would do with
524the static libraries, as described above. But in Step 4,
525you should only need to add the directory where the LIB files are installed
526(i.e. @file{c:\msys\usr\local\bin}). This is not a typo, the LIB files are
527installed in the @file{bin} directory. And instead of adding @file{libxx.a}
528files, you should add @file{avcodec.lib}, @file{avformat.lib}, and
529@file{avutil.lib}. There should be no need for @file{libmingwex.a},
530@file{libgcc.a}, and @file{wsock32.lib}, nor any other external library
531statically linked into the DLLs. The @file{bin} directory contains a bunch
532of DLL files, but the ones that are actually used to run your application
533are the ones with a major version number in their filenames
534(i.e. @file{avcodec-51.dll}).
535
d0e1cd3d
DB
536@subsection Cross compilation for Windows with Linux
537
538You must use the MinGW cross compilation tools available at
539@url{http://www.mingw.org/}.
540
541Then configure FFmpeg with the following options:
542@example
543./configure --target-os=mingw32 --cross-prefix=i386-mingw32msvc-
544@end example
545(you can change the cross-prefix according to the prefix chosen for the
546MinGW tools).
547
548Then you can easily test FFmpeg with Wine
549(@url{http://www.winehq.com/}).
550
551@subsection Compilation under Cygwin
552
29c3d42b
VP
553The main issue with Cygwin is that newlib, its C library, does not
554contain llrint(). However, it is possible to leverage the
555implementation in MinGW.
d0e1cd3d
DB
556
557Just install your Cygwin with all the "Base" packages, plus the
558following "Devel" ones:
559@example
29c3d42b 560binutils, gcc-core, make, subversion, mingw-runtime
d0e1cd3d
DB
561@end example
562
563Do not install binutils-20060709-1 (they are buggy on shared builds);
564use binutils-20050610-1 instead.
565
29c3d42b
VP
566Then create a small library that just contains llrint():
567
568@example
569ar x /usr/lib/mingw/libmingwex.a llrint.o
570ar cq /usr/local/lib/libllrint.a llrint.o
571@end example
572
d0e1cd3d
DB
573Then run
574
575@example
29c3d42b 576./configure --enable-static --disable-shared --extra-ldflags='-L /usr/local/lib' --extra-libs='-l llrint'
d0e1cd3d
DB
577@end example
578
579to make a static build or
580
581@example
29c3d42b 582./configure --enable-shared --disable-static --extra-ldflags='-L /usr/local/lib' --extra-libs='-l llrint'
d0e1cd3d
DB
583@end example
584
585to build shared libraries.
586
587If you want to build FFmpeg with additional libraries, download Cygwin
588"Devel" packages for Ogg and Vorbis from any Cygwin packages repository
589and/or SDL, xvid, faac, faad2 packages from Cygwin Ports,
590(@url{http://cygwinports.dotsrc.org/}).
591
592@subsection Crosscompilation for Windows under Cygwin
593
594With Cygwin you can create Windows binaries that do not need the cygwin1.dll.
595
596Just install your Cygwin as explained before, plus these additional
597"Devel" packages:
598@example
599gcc-mingw-core, mingw-runtime, mingw-zlib
600@end example
601
602and add some special flags to your configure invocation.
603
604For a static build run
605@example
606./configure --target-os=mingw32 --enable-memalign-hack --enable-static --disable-shared --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
607@end example
608
609and for a build with shared libraries
610@example
611./configure --target-os=mingw32 --enable-memalign-hack --enable-shared --disable-static --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
612@end example
613
614@section BeOS
615
5f757b85 616BeOS support is broken in mysterious ways.
d0e1cd3d 617
25b92a79
DY
618@section OS/2
619
620For information about compiling FFmpeg on OS/2 see
621@url{http://www.edm2.com/index.php/FFmpeg}.
622
d0e1cd3d
DB
623@chapter Developers Guide
624
625@section API
626@itemize @bullet
627@item libavcodec is the library containing the codecs (both encoding and
628decoding). Look at @file{libavcodec/apiexample.c} to see how to use it.
629
630@item libavformat is the library containing the file format handling (mux and
631demux code for several formats). Look at @file{ffplay.c} to use it in a
632player. See @file{output_example.c} to use it to generate audio or video
633streams.
634
635@end itemize
636
637@section Integrating libavcodec or libavformat in your program
638
639You can integrate all the source code of the libraries to link them
640statically to avoid any version problem. All you need is to provide a
641'config.mak' and a 'config.h' in the parent directory. See the defines
642generated by ./configure to understand what is needed.
643
644You can use libavcodec or libavformat in your commercial program, but
645@emph{any patch you make must be published}. The best way to proceed is
646to send your patches to the FFmpeg mailing list.
647
648@node Coding Rules
649@section Coding Rules
650
651FFmpeg is programmed in the ISO C90 language with a few additional
652features from ISO C99, namely:
653@itemize @bullet
654@item
655the @samp{inline} keyword;
656@item
657@samp{//} comments;
658@item
659designated struct initializers (@samp{struct s x = @{ .i = 17 @};})
660@item
661compound literals (@samp{x = (struct s) @{ 17, 23 @};})
662@end itemize
663
664These features are supported by all compilers we care about, so we will not
665accept patches to remove their use unless they absolutely do not impair
666clarity and performance.
667
668All code must compile with GCC 2.95 and GCC 3.3. Currently, FFmpeg also
669compiles with several other compilers, such as the Compaq ccc compiler
670or Sun Studio 9, and we would like to keep it that way unless it would
671be exceedingly involved. To ensure compatibility, please do not use any
672additional C99 features or GCC extensions. Especially watch out for:
673@itemize @bullet
674@item
675mixing statements and declarations;
676@item
677@samp{long long} (use @samp{int64_t} instead);
678@item
679@samp{__attribute__} not protected by @samp{#ifdef __GNUC__} or similar;
680@item
681GCC statement expressions (@samp{(x = (@{ int y = 4; y; @})}).
682@end itemize
683
684Indent size is 4.
685The presentation is the one specified by 'indent -i4 -kr -nut'.
686The TAB character is forbidden outside of Makefiles as is any
687form of trailing whitespace. Commits containing either will be
688rejected by the Subversion repository.
689
690The main priority in FFmpeg is simplicity and small code size in order to
691minimize the bug count.
692
693Comments: Use the JavaDoc/Doxygen
694format (see examples below) so that code documentation
695can be generated automatically. All nontrivial functions should have a comment
696above them explaining what the function does, even if it is just one sentence.
697All structures and their member variables should be documented, too.
698@example
699/**
700 * @@file mpeg.c
701 * MPEG codec.
702 * @@author ...
703 */
704
705/**
706 * Summary sentence.
707 * more text ...
708 * ...
709 */
710typedef struct Foobar@{
711 int var1; /**< var1 description */
712 int var2; ///< var2 description
713 /** var3 description */
714 int var3;
715@} Foobar;
716
717/**
718 * Summary sentence.
719 * more text ...
720 * ...
721 * @@param my_parameter description of my_parameter
722 * @@return return value description
723 */
724int myfunc(int my_parameter)
725...
726@end example
727
728fprintf and printf are forbidden in libavformat and libavcodec,
729please use av_log() instead.
730
731Casts should be used only when necessary. Unneeded parentheses
732should also be avoided if they don't make the code easier to understand.
733
734@section Development Policy
735
736@enumerate
737@item
738 Contributions should be licensed under the LGPL 2.1, including an
739 "or any later version" clause, or the MIT license. GPL 2 including
740 an "or any later version" clause is also acceptable, but LGPL is
741 preferred.
742@item
743 You must not commit code which breaks FFmpeg! (Meaning unfinished but
744 enabled code which breaks compilation or compiles but does not work or
745 breaks the regression tests)
746 You can commit unfinished stuff (for testing etc), but it must be disabled
747 (#ifdef etc) by default so it does not interfere with other developers'
748 work.
749@item
750 You do not have to over-test things. If it works for you, and you think it
751 should work for others, then commit. If your code has problems
752 (portability, triggers compiler bugs, unusual environment etc) they will be
753 reported and eventually fixed.
754@item
755 Do not commit unrelated changes together, split them into self-contained
756 pieces. Also do not forget that if part B depends on part A, but A does not
757 depend on B, then A can and should be committed first and separate from B.
758 Keeping changes well split into self-contained parts makes reviewing and
759 understanding them on the commit log mailing list easier. This also helps
760 in case of debugging later on.
761 Also if you have doubts about splitting or not splitting, do not hesitate to
762 ask/discuss it on the developer mailing list.
763@item
764 Do not change behavior of the program (renaming options etc) without
765 first discussing it on the ffmpeg-devel mailing list. Do not remove
766 functionality from the code. Just improve!
767
768 Note: Redundant code can be removed.
769@item
770 Do not commit changes to the build system (Makefiles, configure script)
771 which change behavior, defaults etc, without asking first. The same
772 applies to compiler warning fixes, trivial looking fixes and to code
773 maintained by other developers. We usually have a reason for doing things
774 the way we do. Send your changes as patches to the ffmpeg-devel mailing
775 list, and if the code maintainers say OK, you may commit. This does not
776 apply to files you wrote and/or maintain.
777@item
778 We refuse source indentation and other cosmetic changes if they are mixed
779 with functional changes, such commits will be rejected and removed. Every
780 developer has his own indentation style, you should not change it. Of course
781 if you (re)write something, you can use your own style, even though we would
782 prefer if the indentation throughout FFmpeg was consistent (Many projects
783 force a given indentation style - we do not.). If you really need to make
784 indentation changes (try to avoid this), separate them strictly from real
785 changes.
786
787 NOTE: If you had to put if()@{ .. @} over a large (> 5 lines) chunk of code,
788 then either do NOT change the indentation of the inner part within (do not
789 move it to the right)! or do so in a separate commit
790@item
791 Always fill out the commit log message. Describe in a few lines what you
792 changed and why. You can refer to mailing list postings if you fix a
793 particular bug. Comments such as "fixed!" or "Changed it." are unacceptable.
794@item
795 If you apply a patch by someone else, include the name and email address in
796 the log message. Since the ffmpeg-cvslog mailing list is publicly
797 archived you should add some SPAM protection to the email address. Send an
798 answer to ffmpeg-devel (or wherever you got the patch from) saying that
799 you applied the patch.
800@item
801 When applying patches that have been discussed (at length) on the mailing
802 list, reference the thread in the log message.
803@item
804 Do NOT commit to code actively maintained by others without permission.
805 Send a patch to ffmpeg-devel instead. If no one answers within a reasonable
806 timeframe (12h for build failures and security fixes, 3 days small changes,
807 1 week for big patches) then commit your patch if you think it is OK.
808 Also note, the maintainer can simply ask for more time to review!
809@item
810 Subscribe to the ffmpeg-cvslog mailing list. The diffs of all commits
811 are sent there and reviewed by all the other developers. Bugs and possible
812 improvements or general questions regarding commits are discussed there. We
813 expect you to react if problems with your code are uncovered.
814@item
815 Update the documentation if you change behavior or add features. If you are
816 unsure how best to do this, send a patch to ffmpeg-devel, the documentation
817 maintainer(s) will review and commit your stuff.
818@item
819 Try to keep important discussions and requests (also) on the public
820 developer mailing list, so that all developers can benefit from them.
821@item
822 Never write to unallocated memory, never write over the end of arrays,
823 always check values read from some untrusted source before using them
824 as array index or other risky things.
825@item
826 Remember to check if you need to bump versions for the specific libav
827 parts (libavutil, libavcodec, libavformat) you are changing. You need
828 to change the version integer and the version string.
829 Incrementing the first component means no backward compatibility to
830 previous versions (e.g. removal of a function from the public API).
831 Incrementing the second component means backward compatible change
832 (e.g. addition of a function to the public API).
833 Incrementing the third component means a noteworthy binary compatible
834 change (e.g. encoder bug fix that matters for the decoder).
835@item
836 If you add a new codec, remember to update the changelog, add it to
837 the supported codecs table in the documentation and bump the second
838 component of the @file{libavcodec} version number appropriately. If
839 it has a fourcc, add it to @file{libavformat/avienc.c}, even if it
840 is only a decoder.
841@item
53407b64 842 Compiler warnings indicate potential bugs or code with bad style. If a type of
9908c1a8
DB
843 warning always points to correct and clean code, that warning should
844 be disabled, not the code changed.
845 Thus the remaining warnings can either be bugs or correct code.
beaa4a91 846 If it is a bug, the bug has to be fixed. If it is not, the code should
9908c1a8
DB
847 be changed to not generate a warning unless that causes a slowdown
848 or obfuscates the code.
d0e1cd3d
DB
849@item
850 If you add a new file, give it a proper license header. Do not copy and
851 paste it from a random place, use an existing file as template.
852@end enumerate
853
854We think our rules are not too hard. If you have comments, contact us.
855
856Note, these rules are mostly borrowed from the MPlayer project.
857
858@section Submitting patches
859
860First, (@pxref{Coding Rules}) above if you did not yet.
861
862When you submit your patch, try to send a unified diff (diff '-up'
863option). We cannot read other diffs :-)
864
865Also please do not submit a patch which contains several unrelated changes.
866Split it into separate, self-contained pieces. This does not mean splitting
867file by file. Instead, make the patch as small as possible while still
868keeping it as a logical unit that contains an individual change, even
869if it spans multiple files. This makes reviewing your patches much easier
870for us and greatly increases your chances of getting your patch applied.
871
872Run the regression tests before submitting a patch so that you can
873verify that there are no big problems.
874
875Patches should be posted as base64 encoded attachments (or any other
876encoding which ensures that the patch will not be trashed during
877transmission) to the ffmpeg-devel mailing list, see
878@url{http://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel}
879
880It also helps quite a bit if you tell us what the patch does (for example
881'replaces lrint by lrintf'), and why (for example '*BSD isn't C99 compliant
882and has no lrint()')
883
884Also please if you send several patches, send each patch as a separate mail,
885do not attach several unrelated patches to the same mail.
886
887@section patch submission checklist
888
889@enumerate
890@item
891 Do the regression tests pass with the patch applied?
892@item
893 Is the patch a unified diff?
894@item
895 Is the patch against latest FFmpeg SVN?
896@item
897 Are you subscribed to ffmpeg-dev?
898 (the list is subscribers only due to spam)
899@item
900 Have you checked that the changes are minimal, so that the same cannot be
901 achieved with a smaller patch and/or simpler final code?
902@item
903 If the change is to speed critical code, did you benchmark it?
904@item
905 If you did any benchmarks, did you provide them in the mail?
906@item
907 Have you checked that the patch does not introduce buffer overflows or
908 other security issues?
909@item
910 Is the patch created from the root of the source tree, so it can be
911 applied with @code{patch -p0}?
912@item
913 Does the patch not mix functional and cosmetic changes?
914@item
915 Did you add tabs or trailing whitespace to the code? Both are forbidden.
916@item
917 Is the patch attached to the email you send?
918@item
919 Is the mime type of the patch correct? It should be text/x-diff or
920 text/x-patch or at least text/plain and not application/octet-stream.
921@item
922 If the patch fixes a bug, did you provide a verbose analysis of the bug?
923@item
924 If the patch fixes a bug, did you provide enough information, including
925 a sample, so the bug can be reproduced and the fix can be verified?
926 Note please do not attach samples >100k to mails but rather provide a
927 URL, you can upload to ftp://upload.mplayerhq.hu
928@item
929 Did you provide a verbose summary about what the patch does change?
930@item
931 Did you provide a verbose explanation why it changes things like it does?
932@item
933 Did you provide a verbose summary of the user visible advantages and
934 disadvantages if the patch is applied?
935@item
936 Did you provide an example so we can verify the new feature added by the
937 patch easily?
938@item
939 If you added a new file, did you insert a license header? It should be
940 taken from FFmpeg, not randomly copied and pasted from somewhere else.
941@item
942 You should maintain alphabetical order in alphabetically ordered lists as
943 long as doing so does not break API/ABI compatibility.
944@item
945 Lines with similar content should be aligned vertically when doing so
946 improves readability.
947@item
948 Did you provide a suggestion for a clear commit log message?
27250d20
MN
949@item
950 Did you test your decoder or demuxer against damaged data? If no, see
951 tools/trasher and the noise bitstream filter. Your decoder or demuxer
fe74278f 952 should not crash or end in a (near) infinite loop when fed damaged data.
d0e1cd3d
DB
953@end enumerate
954
955@section Patch review process
956
957All patches posted to ffmpeg-devel will be reviewed, unless they contain a
958clear note that the patch is not for SVN.
959Reviews and comments will be posted as replies to the patch on the
960mailing list. The patch submitter then has to take care of every comment,
961that can be by resubmitting a changed patch or by discussion. Resubmitted
962patches will themselves be reviewed like any other patch. If at some point
963a patch passes review with no comments then it is approved, that can for
964simple and small patches happen immediately while large patches will generally
965have to be changed and reviewed many times before they are approved.
966After a patch is approved it will be committed to the repository.
967
968We will review all submitted patches, but sometimes we are quite busy so
969especially for large patches this can take several weeks.
970
971When resubmitting patches, please do not make any significant changes
972not related to the comments received during review. Such patches will
973be rejected. Instead, submit significant changes or new features as
974separate patches.
975
976@section Regression tests
977
978Before submitting a patch (or committing to the repository), you should at least
979test that you did not break anything.
980
981The regression tests build a synthetic video stream and a synthetic
982audio stream. These are then encoded and decoded with all codecs or
983formats. The CRC (or MD5) of each generated file is recorded in a
984result file. A 'diff' is launched to compare the reference results and
985the result file.
986
987The regression tests then go on to test the FFserver code with a
988limited set of streams. It is important that this step runs correctly
989as well.
990
991Run 'make test' to test all the codecs and formats.
992
993Run 'make fulltest' to test all the codecs, formats and FFserver.
994
995[Of course, some patches may change the results of the regression tests. In
996this case, the reference results of the regression tests shall be modified
997accordingly].
998
999@bye