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[libav.git] / doc / ffmpeg-doc.texi
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1\input texinfo @c -*- texinfo -*-
2
3@settitle FFmpeg Documentation
4@titlepage
5@sp 7
6@center @titlefont{FFmpeg Documentation}
7@sp 3
8@end titlepage
9
10
11@chapter Introduction
12
13FFmpeg is a very fast video and audio converter. It can also grab from
14a live audio/video source.
115329f1 15
9181577c 16The command line interface is designed to be intuitive, in the sense
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17that FFmpeg tries to figure out all parameters that can possibly be
18derived automatically. You usually only have to specify the target
19bitrate you want.
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20
21FFmpeg can also convert from any sample rate to any other, and resize
22video on the fly with a high quality polyphase filter.
23
24@chapter Quick Start
25
e99c4e10 26@c man begin EXAMPLES
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27@section Video and Audio grabbing
28
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29FFmpeg can grab video and audio from devices given that you specify the input
30format and device.
e99c4e10 31
9181577c 32@example
cc58300e 33ffmpeg -f audio_device -i /dev/dsp -f video4linux2 -i /dev/video0 /tmp/out.mpg
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34@end example
35
e99c4e10 36Note that you must activate the right video source and channel before
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37launching FFmpeg with any TV viewer such as xawtv
38(@url{http://bytesex.org/xawtv/}) by Gerd Knorr. You also
39have to set the audio recording levels correctly with a
e99c4e10 40standard mixer.
9181577c 41
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42@section X11 grabbing
43
913e4081 44FFmpeg can grab the X11 display.
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45
46@example
9e0ab666 47ffmpeg -f x11grab -s cif -i :0.0 /tmp/out.mpg
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48@end example
49
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500.0 is display.screen number of your X11 server, same as
51the DISPLAY environment variable.
76d2efda 52
0cd4faf9 53@example
9e0ab666 54ffmpeg -f x11grab -s cif -i :0.0+10,20 /tmp/out.mpg
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55@end example
56
570.0 is display.screen number of your X11 server, same as the DISPLAY environment
58variable. 10 is the x-offset and 20 the y-offset for the grabbing.
59
6bf40f39 60@section Video and Audio file format conversion
9181577c 61
4c5f7207 62* FFmpeg can use any supported file format and protocol as input:
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63
64Examples:
65
4c5f7207 66* You can use YUV files as input:
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67
68@example
115329f1 69ffmpeg -i /tmp/test%d.Y /tmp/out.mpg
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70@end example
71
115329f1 72It will use the files:
9181577c 73@example
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74/tmp/test0.Y, /tmp/test0.U, /tmp/test0.V,
75/tmp/test1.Y, /tmp/test1.U, /tmp/test1.V, etc...
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76@end example
77
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78The Y files use twice the resolution of the U and V files. They are
79raw files, without header. They can be generated by all decent video
80decoders. You must specify the size of the image with the @option{-s} option
4c5f7207 81if FFmpeg cannot guess it.
9181577c 82
4c5f7207 83* You can input from a raw YUV420P file:
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84
85@example
e99c4e10 86ffmpeg -i /tmp/test.yuv /tmp/out.avi
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87@end example
88
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89test.yuv is a file containing raw YUV planar data. Each frame is composed
90of the Y plane followed by the U and V planes at half vertical and
e99c4e10 91horizontal resolution.
9181577c 92
4c5f7207 93* You can output to a raw YUV420P file:
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94
95@example
f926cbe7 96ffmpeg -i mydivx.avi hugefile.yuv
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97@end example
98
99* You can set several input files and output files:
100
101@example
e99c4e10 102ffmpeg -i /tmp/a.wav -s 640x480 -i /tmp/a.yuv /tmp/a.mpg
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103@end example
104
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105Converts the audio file a.wav and the raw YUV video file a.yuv
106to MPEG file a.mpg.
9181577c 107
6bf40f39 108* You can also do audio and video conversions at the same time:
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109
110@example
e99c4e10 111ffmpeg -i /tmp/a.wav -ar 22050 /tmp/a.mp2
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112@end example
113
4c5f7207 114Converts a.wav to MPEG audio at 22050Hz sample rate.
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115
116* You can encode to several formats at the same time and define a
e99c4e10 117mapping from input stream to output streams:
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118
119@example
5438308f 120ffmpeg -i /tmp/a.wav -ab 64k /tmp/a.mp2 -ab 128k /tmp/b.mp2 -map 0:0 -map 0:0
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121@end example
122
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123Converts a.wav to a.mp2 at 64 kbits and to b.mp2 at 128 kbits. '-map
124file:index' specifies which input stream is used for each output
e99c4e10 125stream, in the order of the definition of output streams.
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126
127* You can transcode decrypted VOBs
128
129@example
7b900f2d 130ffmpeg -i snatch_1.vob -f avi -vcodec mpeg4 -b 800k -g 300 -bf 2 -acodec libmp3lame -ab 128k snatch.avi
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131@end example
132
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133This is a typical DVD ripping example; the input is a VOB file, the
134output an AVI file with MPEG-4 video and MP3 audio. Note that in this
135command we use B-frames so the MPEG-4 stream is DivX5 compatible, and
136GOP size is 300 which means one intra frame every 10 seconds for 29.97fps
137input video. Furthermore, the audio stream is MP3-encoded so you need
1cc60c47 138to enable LAME support by passing @code{--enable-libmp3lame} to configure.
4c5f7207 139The mapping is particularly useful for DVD transcoding
e99c4e10 140to get the desired audio language.
9181577c 141
4c5f7207 142NOTE: To see the supported input formats, use @code{ffmpeg -formats}.
e99c4e10 143@c man end
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144
145@chapter Invocation
146
147@section Syntax
148
e99c4e10 149The generic syntax is:
9181577c 150
115329f1 151@example
e99c4e10 152@c man begin SYNOPSIS
28f88dc8 153ffmpeg [[infile options][@option{-i} @var{infile}]]... @{[outfile options] @var{outfile}@}...
e99c4e10 154@c man end
9181577c 155@end example
e99c4e10 156@c man begin DESCRIPTION
e99c4e10 157As a general rule, options are applied to the next specified
699e77b1 158file. Therefore, order is important, and you can have the same
8cc62264 159option on the command line multiple times. Each occurrence is
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160then applied to the next input or output file.
161
eb10acec 162* To set the video bitrate of the output file to 64kbit/s:
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163@example
164ffmpeg -i input.avi -b 64k output.avi
165@end example
166
167* To force the frame rate of the input and output file to 24 fps:
168@example
169ffmpeg -r 24 -i input.avi output.avi
170@end example
171
172* To force the frame rate of the output file to 24 fps:
173@example
174ffmpeg -i input.avi -r 24 output.avi
175@end example
176
177* To force the frame rate of input file to 1 fps and the output file to 24 fps:
178@example
179ffmpeg -r 1 -i input.avi -r 24 output.avi
180@end example
181
182The format option may be needed for raw input files.
9181577c 183
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184By default, FFmpeg tries to convert as losslessly as possible: It
185uses the same audio and video parameters for the outputs as the one
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186specified for the inputs.
187@c man end
9181577c 188
e99c4e10 189@c man begin OPTIONS
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190@section Main options
191
e99c4e10 192@table @option
9181577c 193@item -L
4c5f7207 194Show license.
18bff752 195
9181577c 196@item -h
4c5f7207 197Show help.
18bff752 198
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199@item -version
200Show version.
201
e99c4e10 202@item -formats
4c5f7207 203Show available formats, codecs, protocols, ...
18bff752 204
115329f1 205@item -f fmt
4c5f7207 206Force format.
18bff752 207
115329f1 208@item -i filename
4c5f7207 209input filename
9181577c 210
115329f1 211@item -y
4c5f7207 212Overwrite output files.
9181577c 213
115329f1 214@item -t duration
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215Set the recording time in seconds.
216@code{hh:mm:ss[.xxx]} syntax is also supported.
9181577c 217
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218@item -fs limit_size
219Set the file size limit.
220
e83a84ac 221@item -ss position
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222Seek to given time position in seconds.
223@code{hh:mm:ss[.xxx]} syntax is also supported.
e83a84ac 224
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225@item -itsoffset offset
226Set the input time offset in seconds.
227@code{[-]hh:mm:ss[.xxx]} syntax is also supported.
228This option affects all the input files that follow it.
229The offset is added to the timestamps of the input files.
230Specifying a positive offset means that the corresponding
231streams are delayed by 'offset' seconds.
232
115329f1 233@item -title string
4c5f7207 234Set the title.
9181577c 235
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236@item -timestamp time
237Set the timestamp.
238
115329f1 239@item -author string
4c5f7207 240Set the author.
9181577c 241
115329f1 242@item -copyright string
4c5f7207 243Set the copyright.
9181577c 244
115329f1 245@item -comment string
4c5f7207 246Set the comment.
9181577c 247
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248@item -album string
249Set the album.
250
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251@item -track number
252Set the track.
253
254@item -year number
255Set the year.
256
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257@item -v verbose
258Control amount of logging.
259
99db6420 260@item -target type
4386f941 261Specify target file type ("vcd", "svcd", "dvd", "dv", "dv50", "pal-vcd",
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262"ntsc-svcd", ... ). All the format options (bitrate, codecs,
263buffer sizes) are then set automatically. You can just type:
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264
265@example
266ffmpeg -i myfile.avi -target vcd /tmp/vcd.mpg
267@end example
268
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269Nevertheless you can specify additional options as long as you know
270they do not conflict with the standard, as in:
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271
272@example
273ffmpeg -i myfile.avi -target vcd -bf 2 /tmp/vcd.mpg
274@end example
275
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276@item -dframes number
277Set the number of data frames to record.
278
279@item -scodec codec
280Force subtitle codec ('copy' to copy stream).
281
282@item -newsubtitle
283Add a new subtitle stream to the current output stream.
284
285@item -slang code
286Set the ISO 639 language code (3 letters) of the current subtitle stream.
401fbdde 287
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288@end table
289
290@section Video Options
291
e99c4e10 292@table @option
9181577c 293@item -b bitrate
3c0ba870 294Set the video bitrate in bit/s (default = 200 kb/s).
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295@item -vframes number
296Set the number of video frames to record.
115329f1 297@item -r fps
4386f941 298Set frame rate (Hz value, fraction or abbreviation), (default = 25).
115329f1 299@item -s size
67053c30 300Set frame size. The format is @samp{wxh} (ffserver default = 160x128, ffmpeg default = same as source).
4c5f7207 301The following abbreviations are recognized:
5ee03c86 302@table @samp
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303@item sqcif
304128x96
305@item qcif
306176x144
307@item cif
308352x288
309@item 4cif
310704x576
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311@item qqvga
312160x120
313@item qvga
314320x240
315@item vga
316640x480
317@item svga
318800x600
319@item xga
3201024x768
321@item uxga
3221600x1200
323@item qxga
3242048x1536
325@item sxga
3261280x1024
327@item qsxga
3282560x2048
329@item hsxga
3305120x4096
331@item wvga
332852x480
333@item wxga
3341366x768
335@item wsxga
3361600x1024
337@item wuxga
3381920x1200
339@item woxga
3402560x1600
341@item wqsxga
3423200x2048
343@item wquxga
3443840x2400
345@item whsxga
3466400x4096
347@item whuxga
3487680x4800
349@item cga
350320x200
351@item ega
352640x350
353@item hd480
354852x480
355@item hd720
3561280x720
357@item hd1080
3581920x1080
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359@end table
360
361@item -aspect aspect
4c5f7207 362Set aspect ratio (4:3, 16:9 or 1.3333, 1.7777).
18bff752 363@item -croptop size
4c5f7207 364Set top crop band size (in pixels).
18bff752 365@item -cropbottom size
4c5f7207 366Set bottom crop band size (in pixels).
18bff752 367@item -cropleft size
4c5f7207 368Set left crop band size (in pixels).
18bff752 369@item -cropright size
4c5f7207 370Set right crop band size (in pixels).
1ff93ffc 371@item -padtop size
4c5f7207 372Set top pad band size (in pixels).
1ff93ffc 373@item -padbottom size
4c5f7207 374Set bottom pad band size (in pixels).
1ff93ffc 375@item -padleft size
4c5f7207 376Set left pad band size (in pixels).
1ff93ffc 377@item -padright size
4c5f7207 378Set right pad band size (in pixels).
5b79a73e 379@item -padcolor (hex color)
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380Set color of padded bands. The value for padcolor is expressed
381as a six digit hexadecimal number where the first two digits
382represent red, the middle two digits green and last two digits
383blue (default = 000000 (black)).
9181577c 384@item -vn
4c5f7207 385Disable video recording.
115329f1 386@item -bt tolerance
dc5ee8bc 387Set video bitrate tolerance (in bit/s).
18bff752 388@item -maxrate bitrate
a5515106 389Set max video bitrate tolerance (in bit/s).
18bff752 390@item -minrate bitrate
a5515106 391Set min video bitrate tolerance (in bit/s).
18bff752 392@item -bufsize size
81d0618f 393Set rate control buffer size (in bits).
115329f1 394@item -vcodec codec
4c5f7207 395Force video codec to @var{codec}. Use the @code{copy} special value to
5ee03c86 396tell that the raw codec data must be copied as is.
18bff752 397@item -sameq
4c5f7207 398Use same video quality as source (implies VBR).
9181577c 399
115329f1 400@item -pass n
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401Select the pass number (1 or 2). It is useful to do two pass
402encoding. The statistics of the video are recorded in the first
403pass and the video is generated at the exact requested bitrate
404in the second pass.
9181577c 405
115329f1 406@item -passlogfile file
4c5f7207 407Set two pass logfile name to @var{file}.
9181577c 408
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409@item -newvideo
410Add a new video stream to the current output stream.
411
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412@end table
413
18bff752 414@section Advanced Video Options
9181577c 415
e99c4e10 416@table @option
4386f941 417@item -pix_fmt format
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418Set pixel format. Use 'list' as parameter to show all the supported
419pixel formats.
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420@item -sws_flags flags
421Set SwScaler flags (only available when compiled with SwScaler support).
115329f1 422@item -g gop_size
4c5f7207 423Set the group of pictures size.
115329f1 424@item -intra
4c5f7207 425Use only intra frames.
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426@item -vdt n
427Discard threshold.
115329f1 428@item -qscale q
4bef236b 429Use fixed video quantizer scale (VBR).
115329f1 430@item -qmin q
4bef236b 431minimum video quantizer scale (VBR)
115329f1 432@item -qmax q
4bef236b 433maximum video quantizer scale (VBR)
115329f1 434@item -qdiff q
4bef236b 435maximum difference between the quantizer scales (VBR)
115329f1 436@item -qblur blur
4bef236b 437video quantizer scale blur (VBR)
115329f1 438@item -qcomp compression
4bef236b 439video quantizer scale compression (VBR)
18bff752 440
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441@item -lmin lambda
442minimum video lagrange factor (VBR)
443@item -lmax lambda
444max video lagrange factor (VBR)
445@item -mblmin lambda
446minimum macroblock quantizer scale (VBR)
447@item -mblmax lambda
448maximum macroblock quantizer scale (VBR)
449
450These four options (lmin, lmax, mblmin, mblmax) use 'lambda' units,
451but you may use the QP2LAMBDA constant to easily convert from 'q' units:
452@example
453ffmpeg -i src.ext -lmax 21*QP2LAMBDA dst.ext
454@end example
455
18bff752 456@item -rc_init_cplx complexity
4c5f7207 457initial complexity for single pass encoding
18bff752 458@item -b_qfactor factor
4c5f7207 459qp factor between P- and B-frames
18bff752 460@item -i_qfactor factor
4c5f7207 461qp factor between P- and I-frames
18bff752 462@item -b_qoffset offset
4c5f7207 463qp offset between P- and B-frames
18bff752 464@item -i_qoffset offset
4c5f7207 465qp offset between P- and I-frames
18bff752 466@item -rc_eq equation
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467Set rate control equation (@pxref{FFmpeg formula
468evaluator}) (default = @code{tex^qComp}).
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469@item -rc_override override
470rate control override for specific intervals
18bff752 471@item -me method
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472Set motion estimation method to @var{method}.
473Available methods are (from lowest to best quality):
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474@table @samp
475@item zero
5ee03c86 476Try just the (0, 0) vector.
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477@item phods
478@item log
479@item x1
480@item epzs
481(default method)
482@item full
483exhaustive search (slow and marginally better than epzs)
484@end table
485
486@item -dct_algo algo
4c5f7207 487Set DCT algorithm to @var{algo}. Available values are:
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488@table @samp
489@item 0
490FF_DCT_AUTO (default)
491@item 1
492FF_DCT_FASTINT
493@item 2
494FF_DCT_INT
495@item 3
496FF_DCT_MMX
497@item 4
498FF_DCT_MLIB
499@item 5
500FF_DCT_ALTIVEC
501@end table
502
503@item -idct_algo algo
4c5f7207 504Set IDCT algorithm to @var{algo}. Available values are:
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505@table @samp
506@item 0
507FF_IDCT_AUTO (default)
508@item 1
115329f1 509FF_IDCT_INT
18bff752 510@item 2
115329f1 511FF_IDCT_SIMPLE
18bff752 512@item 3
115329f1 513FF_IDCT_SIMPLEMMX
18bff752 514@item 4
115329f1 515FF_IDCT_LIBMPEG2MMX
18bff752 516@item 5
115329f1 517FF_IDCT_PS2
18bff752 518@item 6
115329f1 519FF_IDCT_MLIB
18bff752 520@item 7
115329f1 521FF_IDCT_ARM
18bff752 522@item 8
115329f1 523FF_IDCT_ALTIVEC
18bff752 524@item 9
115329f1 525FF_IDCT_SH4
18bff752 526@item 10
115329f1 527FF_IDCT_SIMPLEARM
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528@end table
529
530@item -er n
4c5f7207 531Set error resilience to @var{n}.
18bff752 532@table @samp
115329f1 533@item 1
1471c6c2 534FF_ER_CAREFUL (default)
18bff752 535@item 2
5ee03c86 536FF_ER_COMPLIANT
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537@item 3
538FF_ER_AGGRESSIVE
539@item 4
540FF_ER_VERY_AGGRESSIVE
541@end table
542
5ee03c86 543@item -ec bit_mask
4c5f7207 544Set error concealment to @var{bit_mask}. @var{bit_mask} is a bit mask of
5ee03c86 545the following values:
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546@table @samp
547@item 1
4c5f7207 548FF_EC_GUESS_MVS (default = enabled)
18bff752 549@item 2
4c5f7207 550FF_EC_DEBLOCK (default = enabled)
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551@end table
552
553@item -bf frames
4c5f7207 554Use 'frames' B-frames (supported for MPEG-1, MPEG-2 and MPEG-4).
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555@item -mbd mode
556macroblock decision
557@table @samp
558@item 0
4c5f7207 559FF_MB_DECISION_SIMPLE: Use mb_cmp (cannot change it yet in FFmpeg).
18bff752 560@item 1
4c5f7207 561FF_MB_DECISION_BITS: Choose the one which needs the fewest bits.
18bff752 562@item 2
019c8838 563FF_MB_DECISION_RD: rate distortion
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564@end table
565
566@item -4mv
4c5f7207 567Use four motion vector by macroblock (MPEG-4 only).
18bff752 568@item -part
4c5f7207 569Use data partitioning (MPEG-4 only).
18bff752 570@item -bug param
4c5f7207 571Work around encoder bugs that are not auto-detected.
18bff752 572@item -strict strictness
4c5f7207 573How strictly to follow the standards.
5ee03c86 574@item -aic
4c5f7207 575Enable Advanced intra coding (h263+).
5ee03c86 576@item -umv
4c5f7207 577Enable Unlimited Motion Vector (h263+)
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578
579@item -deinterlace
4c5f7207 580Deinterlace pictures.
3841e813 581@item -ilme
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582Force interlacing support in encoder (MPEG-2 and MPEG-4 only).
583Use this option if your input file is interlaced and you want
584to keep the interlaced format for minimum losses.
585The alternative is to deinterlace the input stream with
586@option{-deinterlace}, but deinterlacing introduces losses.
18bff752 587@item -psnr
4c5f7207 588Calculate PSNR of compressed frames.
18bff752 589@item -vstats
4c5f7207 590Dump video coding statistics to @file{vstats_HHMMSS.log}.
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591@item -vstats_file file
592Dump video coding statistics to @var{file}.
18bff752 593@item -vhook module
4c5f7207 594Insert video processing @var{module}. @var{module} contains the module
18bff752 595name and its parameters separated by spaces.
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596@item -top n
597top=1/bottom=0/auto=-1 field first
598@item -dc precision
599Intra_dc_precision.
600@item -vtag fourcc/tag
601Force video tag/fourcc.
602@item -qphist
603Show QP histogram.
604@item -vbsf bitstream filter
605Bitstream filters available are "dump_extra", "remove_extra", "noise".
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606@end table
607
608@section Audio Options
609
610@table @option
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611@item -aframes number
612Set the number of audio frames to record.
115329f1 613@item -ar freq
4c5f7207 614Set the audio sampling frequency (default = 44100 Hz).
115329f1 615@item -ab bitrate
5438308f 616Set the audio bitrate in bit/s (default = 64k).
18bff752 617@item -ac channels
4c5f7207 618Set the number of audio channels (default = 1).
5ee03c86 619@item -an
4c5f7207 620Disable audio recording.
5ee03c86 621@item -acodec codec
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622Force audio codec to @var{codec}. Use the @code{copy} special value to
623specify that the raw codec data must be copied as is.
de62a89d 624@item -newaudio
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625Add a new audio track to the output file. If you want to specify parameters,
626do so before @code{-newaudio} (@code{-acodec}, @code{-ab}, etc..).
de62a89d 627
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628Mapping will be done automatically, if the number of output streams is equal to
629the number of input streams, else it will pick the first one that matches. You
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630can override the mapping using @code{-map} as usual.
631
632Example:
633@example
5438308f 634ffmpeg -i file.mpg -vcodec copy -acodec ac3 -ab 384k test.mpg -acodec mp2 -ab 192k -newaudio
de62a89d 635@end example
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636@item -alang code
637Set the ISO 639 language code (3 letters) of the current audio stream.
638@end table
639
640@section Advanced Audio options:
641
642@table @option
643@item -atag fourcc/tag
644Force audio tag/fourcc.
645@item -absf bitstream filter
646Bitstream filters available are "dump_extra", "remove_extra", "noise", "mp3comp", "mp3decomp".
647@end table
648
649@section Subtitle options:
650
651@table @option
652@item -scodec codec
653Force subtitle codec ('copy' to copy stream).
654@item -newsubtitle
655Add a new subtitle stream to the current output stream.
656@item -slang code
657Set the ISO 639 language code (3 letters) of the current subtitle stream.
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658@end table
659
660@section Audio/Video grab options
661
662@table @option
18bff752 663@item -vc channel
4c5f7207 664Set video grab channel (DV1394 only).
18bff752 665@item -tvstd standard
4c5f7207 666Set television standard (NTSC, PAL (SECAM)).
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667@item -isync
668Synchronize read on input.
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669@end table
670
671@section Advanced options
672
673@table @option
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674@item -map input stream id[:input stream id]
675Set stream mapping from input streams to output streams.
676Just enumerate the input streams in the order you want them in the output.
677[input stream id] sets the (input) stream to sync against.
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678@item -map_meta_data outfile:infile
679Set meta data information of outfile from infile.
18bff752 680@item -debug
4c5f7207 681Print specific debug info.
115329f1 682@item -benchmark
4c5f7207 683Add timings for benchmarking.
4386f941 684@item -dump
4c5f7207 685Dump each input packet.
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686@item -hex
687When dumping packets, also dump the payload.
18bff752 688@item -bitexact
4c5f7207 689Only use bit exact algorithms (for codec testing).
18bff752 690@item -ps size
4c5f7207 691Set packet size in bits.
5ee03c86 692@item -re
4c5f7207 693Read input at native frame rate. Mainly used to simulate a grab device.
4386f941 694@item -loop_input
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695Loop over the input stream. Currently it works only for image
696streams. This option is used for automatic FFserver testing.
8108551a 697@item -loop_output number_of_times
019c8838 698Repeatedly loop output for formats that support looping such as animated GIF
4c5f7207 699(0 will loop the output infinitely).
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700@item -threads count
701Thread count.
c52e13f1 702@item -vsync parameter
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703Video sync method. Video will be stretched/squeezed to match the timestamps,
704it is done by duplicating and dropping frames. With -map you can select from
705which stream the timestamps should be taken. You can leave either video or
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706audio unchanged and sync the remaining stream(s) to the unchanged one.
707@item -async samples_per_second
29c9183c 708Audio sync method. "Stretches/squeezes" the audio stream to match the timestamps,
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709the parameter is the maximum samples per second by which the audio is changed.
710-async 1 is a special case where only the start of the audio stream is corrected
711without any later correction.
9181577c 712@end table
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713
714@node FFmpeg formula evaluator
715@section FFmpeg formula evaluator
716
717When evaluating a rate control string, FFmpeg uses an internal formula
115329f1 718evaluator.
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719
720The following binary operators are available: @code{+}, @code{-},
721@code{*}, @code{/}, @code{^}.
722
723The following unary operators are available: @code{+}, @code{-},
724@code{(...)}.
725
726The following functions are available:
727@table @var
728@item sinh(x)
729@item cosh(x)
730@item tanh(x)
731@item sin(x)
732@item cos(x)
733@item tan(x)
734@item exp(x)
735@item log(x)
736@item squish(x)
737@item gauss(x)
738@item abs(x)
739@item max(x, y)
740@item min(x, y)
741@item gt(x, y)
742@item lt(x, y)
743@item eq(x, y)
744@item bits2qp(bits)
745@item qp2bits(qp)
746@end table
747
748The following constants are available:
749@table @var
750@item PI
751@item E
752@item iTex
753@item pTex
754@item tex
755@item mv
756@item fCode
757@item iCount
758@item mcVar
759@item var
760@item isI
761@item isP
762@item isB
763@item avgQP
764@item qComp
765@item avgIITex
766@item avgPITex
767@item avgPPTex
768@item avgBPTex
769@item avgTex
770@end table
771
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772@c man end
773
774@ignore
775
776@setfilename ffmpeg
777@settitle FFmpeg video converter
778
779@c man begin SEEALSO
019c8838 780ffserver(1), ffplay(1) and the HTML documentation of @file{ffmpeg}.
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781@c man end
782
783@c man begin AUTHOR
784Fabrice Bellard
785@c man end
786
787@end ignore
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788
789@section Protocols
790
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791The filename can be @file{-} to read from standard input or to write
792to standard output.
9181577c 793
4c5f7207 794FFmpeg also handles many protocols specified with an URL syntax.
9181577c 795
4c5f7207 796Use 'ffmpeg -formats' to see a list of the supported protocols.
9181577c 797
e99c4e10 798The protocol @code{http:} is currently used only to communicate with
4c5f7207 799FFserver (see the FFserver documentation). When FFmpeg will be a
e99c4e10 800video player it will also be used for streaming :-)
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801
802@chapter Tips
803
804@itemize
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805@item For streaming at very low bitrate application, use a low frame rate
806and a small GOP size. This is especially true for RealVideo where
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807the Linux player does not seem to be very fast, so it can miss
808frames. An example is:
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809
810@example
3c0ba870 811ffmpeg -g 3 -r 3 -t 10 -b 50k -s qcif -f rv10 /tmp/b.rm
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812@end example
813
814@item The parameter 'q' which is displayed while encoding is the current
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815quantizer. The value 1 indicates that a very good quality could
816be achieved. The value 31 indicates the worst quality. If q=31 appears
e99c4e10 817too often, it means that the encoder cannot compress enough to meet
4c5f7207 818your bitrate. You must either increase the bitrate, decrease the
e99c4e10 819frame rate or decrease the frame size.
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820
821@item If your computer is not fast enough, you can speed up the
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822compression at the expense of the compression ratio. You can use
823'-me zero' to speed up motion estimation, and '-intra' to disable
4c5f7207 824motion estimation completely (you have only I-frames, which means it
e99c4e10 825is about as good as JPEG compression).
9181577c 826
4c5f7207 827@item To have very low audio bitrates, reduce the sampling frequency
019c8838 828(down to 22050 kHz for MPEG audio, 22050 or 11025 for AC3).
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829
830@item To have a constant quality (but a variable bitrate), use the option
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831'-qscale n' when 'n' is between 1 (excellent quality) and 31 (worst
832quality).
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833
834@item When converting video files, you can use the '-sameq' option which
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835uses the same quality factor in the encoder as in the decoder.
836It allows almost lossless encoding.
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837
838@end itemize
839
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840
841@chapter external libraries
842
843FFmpeg can be hooked up with a number of external libraries to add support
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844for more formats. None of them are used by default, their use has to be
845explicitly requested by passing the appropriate flags to @file{./configure}.
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846
847@section AMR
848
849AMR comes in two different flavors, WB and NB. FFmpeg can make use of the
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850AMR WB (floating-point mode) and the AMR NB (floating-point mode) reference
851decoders and encoders.
47404f9f 852
73508bc6 853Go to @url{http://www.penguin.cz/~utx/amr} and follow the instructions for
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854installing the libraries. Then pass @code{--enable-libamr-nb} and/or
855@code{--enable-libamr-wb} to configure to enable the libraries.
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856
857
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858@chapter Supported File Formats and Codecs
859
860You can use the @code{-formats} option to have an exhaustive list.
861
862@section File Formats
863
6bf40f39 864FFmpeg supports the following file formats through the @code{libavformat}
0699d2fe 865library:
9181577c 866
3fc9e78f 867@multitable @columnfractions .4 .1 .1 .4
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868@item Supported File Format @tab Encoding @tab Decoding @tab Comments
869@item MPEG audio @tab X @tab X
4c5f7207 870@item MPEG-1 systems @tab X @tab X
9181577c 871@tab muxed audio and video
4c5f7207 872@item MPEG-2 PS @tab X @tab X
9181577c 873@tab also known as @code{VOB} file
4c5f7207 874@item MPEG-2 TS @tab @tab X
9181577c 875@tab also known as DVB Transport Stream
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876@item ASF@tab X @tab X
877@item AVI@tab X @tab X
878@item WAV@tab X @tab X
9181577c 879@item Macromedia Flash@tab X @tab X
4c5f7207 880@tab Only embedded audio is decoded.
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881@item FLV @tab X @tab X
882@tab Macromedia Flash video files
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883@item Real Audio and Video @tab X @tab X
884@item Raw AC3 @tab X @tab X
885@item Raw MJPEG @tab X @tab X
886@item Raw MPEG video @tab X @tab X
887@item Raw PCM8/16 bits, mulaw/Alaw@tab X @tab X
888@item Raw CRI ADX audio @tab X @tab X
889@item Raw Shorten audio @tab @tab X
890@item SUN AU format @tab X @tab X
7fe4c823 891@item NUT @tab X @tab X @tab NUT Open Container Format
115329f1 892@item QuickTime @tab X @tab X
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893@item MPEG-4 @tab X @tab X
894@tab MPEG-4 is a variant of QuickTime.
115329f1 895@item Raw MPEG4 video @tab X @tab X
4fa1c4fa 896@item DV @tab X @tab X
701b603d 897@item 4xm @tab @tab X
4c5f7207 898@tab 4X Technologies format, used in some games.
4d3b1f8d 899@item Playstation STR @tab @tab X
13dec857 900@item Id RoQ @tab X @tab X
4c5f7207 901@tab Used in Quake III, Jedi Knight 2, other computer games.
4d3b1f8d 902@item Interplay MVE @tab @tab X
4c5f7207 903@tab Format used in various Interplay computer games.
b17e9c99 904@item WC3 Movie @tab @tab X
4c5f7207 905@tab Multimedia format used in Origin's Wing Commander III computer game.
2fdf638b 906@item Sega FILM/CPK @tab @tab X
4c5f7207 907@tab Used in many Sega Saturn console games.
2fdf638b 908@item Westwood Studios VQA/AUD @tab @tab X
4c5f7207 909@tab Multimedia formats used in Westwood Studios games.
4120a53a 910@item Id Cinematic (.cin) @tab @tab X
4c5f7207 911@tab Used in Quake II.
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912@item FLIC format @tab @tab X
913@tab .fli/.flc files
da00f30e 914@item Sierra VMD @tab @tab X
4c5f7207 915@tab Used in Sierra CD-ROM games.
d08d7142 916@item Sierra Online @tab @tab X
4c5f7207 917@tab .sol files used in Sierra Online games.
38088adf 918@item Matroska @tab @tab X
ad81a9fe 919@item Electronic Arts Multimedia @tab @tab X
4c5f7207 920@tab Used in various EA games; files have extensions like WVE and UV2.
353147ed 921@item Nullsoft Video (NSV) format @tab @tab X
4accd1fd 922@item ADTS AAC audio @tab X @tab X
ea395e8c 923@item Creative VOC @tab X @tab X @tab Created for the Sound Blaster Pro.
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924@item American Laser Games MM @tab @tab X
925@tab Multimedia format used in games like Mad Dog McCree
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926@item AVS @tab @tab X
927@tab Multimedia format used by the Creature Shock game.
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928@item Smacker @tab @tab X
929@tab Multimedia format used by many games.
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930@item GXF @tab X @tab X
931@tab General eXchange Format SMPTE 360M, used by Thomson Grass Valley playout servers.
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932@item CIN @tab @tab X
933@tab Multimedia format used by Delphine Software games.
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934@item MXF @tab @tab X
935@tab Material eXchange Format SMPTE 377M, used by D-Cinema, broadcast industry.
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936@item SEQ @tab @tab X
937@tab Tiertex .seq files used in the DOS CDROM version of the game Flashback.
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938@item DXA @tab @tab X
939@tab This format is used in non-Windows version of Feeble Files game and
940different game cutscenes repacked for use with ScummVM.
efb0c399 941@item THP @tab @tab X
d1e0d21f 942@tab Used on the Nintendo GameCube.
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943@item C93 @tab @tab X
944@tab Used in the game Cyberia from Interplay.
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945@item Bethsoft VID @tab @tab X
946@tab Used in some games from Bethesda Softworks.
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947@item CRYO APC @tab @tab X
948@tab Audio format used in some games by CRYO Interactive Entertainment.
353147ed 949@end multitable
9181577c 950
4c5f7207 951@code{X} means that encoding (resp. decoding) is supported.
9181577c 952
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953@section Image Formats
954
955FFmpeg can read and write images for each frame of a video sequence. The
956following image formats are supported:
957
3fc9e78f 958@multitable @columnfractions .4 .1 .1 .4
0699d2fe 959@item Supported Image Format @tab Encoding @tab Decoding @tab Comments
115329f1 960@item PGM, PPM @tab X @tab X
4c5f7207 961@item PAM @tab X @tab X @tab PAM is a PNM extension with alpha support.
2eb5d024 962@item PGMYUV @tab X @tab X @tab PGM with U and V components in YUV 4:2:0
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963@item JPEG @tab X @tab X @tab Progressive JPEG is not supported.
964@item .Y.U.V @tab X @tab X @tab one raw file per component
965@item animated GIF @tab X @tab X @tab Only uncompressed GIFs are generated.
966@item PNG @tab X @tab X @tab 2 bit and 4 bit/pixel not supported yet.
3689cf16 967@item Targa @tab @tab X @tab Targa (.TGA) image format.
716222db 968@item TIFF @tab X @tab X @tab YUV, JPEG and some extension is not supported yet.
6a91ec51 969@item SGI @tab X @tab X @tab SGI RGB image format
d58bbf81 970@item PTX @tab @tab X @tab V.Flash PTX format
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971@end multitable
972
4c5f7207 973@code{X} means that encoding (resp. decoding) is supported.
0699d2fe 974
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975@section Video Codecs
976
3fc9e78f 977@multitable @columnfractions .4 .1 .1 .4
9181577c 978@item Supported Codec @tab Encoding @tab Decoding @tab Comments
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979@item MPEG-1 video @tab X @tab X
980@item MPEG-2 video @tab X @tab X
2bc5da7b 981@item MPEG-4 @tab X @tab X
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982@item MSMPEG4 V1 @tab X @tab X
983@item MSMPEG4 V2 @tab X @tab X
2bc5da7b 984@item MSMPEG4 V3 @tab X @tab X
9181577c 985@item WMV7 @tab X @tab X
4c5f7207 986@item WMV8 @tab X @tab X @tab not completely working
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987@item WMV9 @tab @tab X @tab not completely working
988@item VC1 @tab @tab X
b06b45c4 989@item H.261 @tab X @tab X
4c5f7207 990@item H.263(+) @tab X @tab X @tab also known as RealVideo 1.0
b06b45c4 991@item H.264 @tab @tab X
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992@item RealVideo 1.0 @tab X @tab X
993@item RealVideo 2.0 @tab X @tab X
115329f1 994@item MJPEG @tab X @tab X
4c5f7207 995@item lossless MJPEG @tab X @tab X
26d6d032 996@item JPEG-LS @tab X @tab X @tab fourcc: MJLS, lossless and near-lossless is supported
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997@item Apple MJPEG-B @tab @tab X
998@item Sunplus MJPEG @tab @tab X @tab fourcc: SP5X
115329f1 999@item DV @tab X @tab X
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1000@item HuffYUV @tab X @tab X
1001@item FFmpeg Video 1 @tab X @tab X @tab experimental lossless codec (fourcc: FFV1)
1002@item FFmpeg Snow @tab X @tab X @tab experimental wavelet codec (fourcc: SNOW)
701b603d 1003@item Asus v1 @tab X @tab X @tab fourcc: ASV1
4d3b1f8d 1004@item Asus v2 @tab X @tab X @tab fourcc: ASV2
701b603d 1005@item Creative YUV @tab @tab X @tab fourcc: CYUV
d2bfadc0 1006@item Sorenson Video 1 @tab X @tab X @tab fourcc: SVQ1
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1007@item Sorenson Video 3 @tab @tab X @tab fourcc: SVQ3
1008@item On2 VP3 @tab @tab X @tab still experimental
5ce117c3 1009@item On2 VP5 @tab @tab X @tab fourcc: VP50
9110a0e3 1010@item On2 VP6 @tab @tab X @tab fourcc: VP60,VP61,VP62
150d2772 1011@item Theora @tab X @tab X @tab still experimental
cdb2c1ca 1012@item Intel Indeo 3 @tab @tab X
9303d49c 1013@item FLV @tab X @tab X @tab Sorenson H.263 used in Flash
15419468 1014@item Flash Screen Video @tab X @tab X @tab fourcc: FSV1
4d3b1f8d 1015@item ATI VCR1 @tab @tab X @tab fourcc: VCR1
7fe4c823 1016@item ATI VCR2 @tab @tab X @tab fourcc: VCR2
4d3b1f8d 1017@item Cirrus Logic AccuPak @tab @tab X @tab fourcc: CLJR
4c5f7207 1018@item 4X Video @tab @tab X @tab Used in certain computer games.
115329f1 1019@item Sony Playstation MDEC @tab @tab X
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1020@item Id RoQ @tab @tab X @tab Used in Quake III, Jedi Knight 2, other computer games.
1021@item Xan/WC3 @tab @tab X @tab Used in Wing Commander III .MVE files.
1022@item Interplay Video @tab @tab X @tab Used in Interplay .MVE files.
070ed1bc 1023@item Apple Animation @tab @tab X @tab fourcc: 'rle '
42cad81a 1024@item Apple Graphics @tab @tab X @tab fourcc: 'smc '
2fdf638b 1025@item Apple Video @tab @tab X @tab fourcc: rpza
d08d7142 1026@item Apple QuickDraw @tab @tab X @tab fourcc: qdrw
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1027@item Cinepak @tab @tab X
1028@item Microsoft RLE @tab @tab X
1029@item Microsoft Video-1 @tab @tab X
4120a53a 1030@item Westwood VQA @tab @tab X
4c5f7207 1031@item Id Cinematic Video @tab @tab X @tab Used in Quake II.
1dc1ed99 1032@item Planar RGB @tab @tab X @tab fourcc: 8BPS
42cad81a 1033@item FLIC video @tab @tab X
9a4117d5 1034@item Duck TrueMotion v1 @tab @tab X @tab fourcc: DUCK
dce76c20 1035@item Duck TrueMotion v2 @tab @tab X @tab fourcc: TM20
4c5f7207 1036@item VMD Video @tab @tab X @tab Used in Sierra VMD files.
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1037@item MSZH @tab @tab X @tab Part of LCL
1038@item ZLIB @tab X @tab X @tab Part of LCL, encoder experimental
9d53d58e 1039@item TechSmith Camtasia @tab @tab X @tab fourcc: TSCC
d0a0bbd2 1040@item IBM Ultimotion @tab @tab X @tab fourcc: ULTI
ab711b3c 1041@item Miro VideoXL @tab @tab X @tab fourcc: VIXL
acfd8f0f 1042@item QPEG @tab @tab X @tab fourccs: QPEG, Q1.0, Q1.1
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1043@item LOCO @tab @tab X @tab
1044@item Winnov WNV1 @tab @tab X @tab
589f8220 1045@item Autodesk Animator Studio Codec @tab @tab X @tab fourcc: AASC
115329f1 1046@item Fraps FPS1 @tab @tab X @tab
2b6c1d80 1047@item CamStudio @tab @tab X @tab fourcc: CSCD
4e114829 1048@item American Laser Games Video @tab @tab X @tab Used in games like Mad Dog McCree
f48d6e1b 1049@item ZMBV @tab X @tab X @tab Encoder works only on PAL8
26376701 1050@item AVS Video @tab @tab X @tab Video encoding used by the Creature Shock game.
348efc18 1051@item Smacker Video @tab @tab X @tab Video encoding used in Smacker.
dfca23e3 1052@item RTjpeg @tab @tab X @tab Video encoding used in NuppelVideo files.
fd7b1991 1053@item KMVC @tab @tab X @tab Codec used in Worms games.
eb57c889 1054@item VMware Video @tab @tab X @tab Codec used in videos captured by VMware.
dc56e0de 1055@item Cin Video @tab @tab X @tab Codec used in Delphine Software games.
29f86228 1056@item Tiertex Seq Video @tab @tab X @tab Codec used in DOS CDROM FlashBack game.
33a0dd37 1057@item DXA Video @tab @tab X @tab Codec originally used in Feeble Files game.
52b6bad2 1058@item AVID DNxHD @tab @tab X @tab aka SMPTE VC3
9a0ddd09 1059@item C93 Video @tab @tab X @tab Codec used in Cyberia game.
8845202e 1060@item THP @tab @tab X @tab Used on the Nintendo GameCube.
1e6c6759 1061@item Bethsoft VID @tab @tab X @tab Used in some games from Bethesda Softworks.
12b6d7c0 1062@item Renderware TXD @tab @tab X @tab Texture dictionaries used by the Renderware Engine.
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1063@end multitable
1064
4c5f7207 1065@code{X} means that encoding (resp. decoding) is supported.
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1066
1067@section Audio Codecs
1068
1069@multitable @columnfractions .4 .1 .1 .1 .7
1070@item Supported Codec @tab Encoding @tab Decoding @tab Comments
115329f1 1071@item MPEG audio layer 2 @tab IX @tab IX
9181577c 1072@item MPEG audio layer 1/3 @tab IX @tab IX
4c5f7207 1073@tab MP3 encoding is supported through the external library LAME.
37776c3b 1074@item AC3 @tab IX @tab IX
4c5f7207 1075@tab liba52 is used internally for decoding.
34d7008d 1076@item Vorbis @tab X @tab X
74882049 1077@item WMA V1/V2 @tab X @tab X
f6fa7a6c 1078@item AAC @tab X @tab X
4c5f7207 1079@tab Supported through the external library libfaac/libfaad.
d4c3c5a6 1080@item Microsoft ADPCM @tab X @tab X
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1081@item MS IMA ADPCM @tab X @tab X
1082@item QT IMA ADPCM @tab @tab X
1083@item 4X IMA ADPCM @tab @tab X
d4e437df 1084@item G.726 ADPCM @tab X @tab X
b17e9c99 1085@item Duck DK3 IMA ADPCM @tab @tab X
4c5f7207 1086@tab Used in some Sega Saturn console games.
b17e9c99 1087@item Duck DK4 IMA ADPCM @tab @tab X
4c5f7207 1088@tab Used in some Sega Saturn console games.
2fdf638b 1089@item Westwood Studios IMA ADPCM @tab @tab X
4c5f7207 1090@tab Used in Westwood Studios games like Command and Conquer.
7d8379f2 1091@item SMJPEG IMA ADPCM @tab @tab X
4c5f7207 1092@tab Used in certain Loki game ports.
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1093@item CD-ROM XA ADPCM @tab @tab X
1094@item CRI ADX ADPCM @tab X @tab X
4c5f7207 1095@tab Used in Sega Dreamcast games.
7d8379f2 1096@item Electronic Arts ADPCM @tab @tab X
4c5f7207 1097@tab Used in various EA titles.
b3bfb299 1098@item Creative ADPCM @tab @tab X
2433f24f 1099@tab 16 -> 4, 8 -> 4, 8 -> 3, 8 -> 2
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1100@item THP ADPCM @tab @tab X
1101@tab Used on the Nintendo GameCube.
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1102@item RA144 @tab @tab X
1103@tab Real 14400 bit/s codec
1104@item RA288 @tab @tab X
1105@tab Real 28800 bit/s codec
37776c3b 1106@item RADnet @tab X @tab IX
4c5f7207 1107@tab Real low bitrate AC3 codec, liba52 is used for decoding.
2eb5d024 1108@item AMR-NB @tab X @tab X
4c5f7207 1109@tab Supported through an external library.
d663a1fd 1110@item AMR-WB @tab X @tab X
4c5f7207 1111@tab Supported through an external library.
2eb5d024 1112@item DV audio @tab @tab X
b09432ad 1113@item Id RoQ DPCM @tab X @tab X
4c5f7207 1114@tab Used in Quake III, Jedi Knight 2, other computer games.
4d3b1f8d 1115@item Interplay MVE DPCM @tab @tab X
4c5f7207 1116@tab Used in various Interplay computer games.
b17e9c99 1117@item Xan DPCM @tab @tab X
4c5f7207 1118@tab Used in Origin's Wing Commander IV AVI files.
d08d7142 1119@item Sierra Online DPCM @tab @tab X
4c5f7207 1120@tab Used in Sierra Online game audio files.
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1121@item Apple MACE 3 @tab @tab X
1122@item Apple MACE 6 @tab @tab X
bfd9a00f 1123@item FLAC lossless audio @tab X @tab X
13dfd2b9 1124@item Shorten lossless audio @tab @tab X
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1125@item Apple lossless audio @tab @tab X
1126@tab QuickTime fourcc 'alac'
33a4d8b1 1127@item FFmpeg Sonic @tab X @tab X
4c5f7207 1128@tab experimental lossy/lossless codec
d9b1c197
RT
1129@item Qdesign QDM2 @tab @tab X
1130@tab there are still some distortions
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1131@item Real COOK @tab @tab X
1132@tab All versions except 5.1 are supported
e839a994 1133@item DSP Group TrueSpeech @tab @tab X
3dc411c0 1134@item True Audio (TTA) @tab @tab X
348efc18 1135@item Smacker Audio @tab @tab X
730581f3 1136@item WavPack Audio @tab @tab X
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1137@item Cin Audio @tab @tab X
1138@tab Codec used in Delphine Software games.
84ed36da 1139@item Intel Music Coder @tab @tab X
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1140@item Musepack @tab @tab X
1141@tab Only SV7 is supported
01ca9ac3 1142@item DT$ Coherent Audio @tab @tab X
10e26bc7 1143@item ATRAC 3 @tab @tab X
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1144@end multitable
1145
4c5f7207 1146@code{X} means that encoding (resp. decoding) is supported.
9181577c 1147
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1148@code{I} means that an integer-only version is available, too (ensures high
1149performance on systems without hardware floating point support).
9181577c 1150
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1151@chapter Platform Specific information
1152
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1153@section BSD
1154
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1155BSD make will not build FFmpeg, you need to install and use GNU Make
1156(@file{gmake}).
1157
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1158@section Windows
1159
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1160To get help and instructions for using FFmpeg under Windows, check out
1161the FFmpeg Windows Help Forum at
1162@url{http://arrozcru.no-ip.org/ffmpeg/}.
1163
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1164@subsection Native Windows compilation
1165
1166@itemize
1167@item Install the current versions of MSYS and MinGW from
1168@url{http://www.mingw.org/}. You can find detailed installation
1169instructions in the download section and the FAQ.
1170
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1171NOTE: Use at least bash 3.1. Older versions are known to be failing on the
1172configure script.
1173
4c5f7207 1174@item If you want to test the FFplay, also download
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1175the MinGW development library of SDL 1.2.x
1176(@file{SDL-devel-1.2.x-mingw32.tar.gz}) from
4c5f7207 1177@url{http://www.libsdl.org}. Unpack it in a temporary directory, and
50f52fcd 1178unpack the archive @file{i386-mingw32msvc.tar.gz} in the MinGW tool
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1179directory. Edit the @file{sdl-config} script so that it gives the
1180correct SDL directory when invoked.
50f52fcd 1181
e926e391 1182@item Extract the current version of FFmpeg.
115329f1 1183
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1184@item Start the MSYS shell (file @file{msys.bat}).
1185
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1186@item Change to the FFmpeg directory and follow
1187 the instructions of how to compile FFmpeg (file
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1188@file{INSTALL}). Usually, launching @file{./configure} and @file{make}
1189suffices. If you have problems using SDL, verify that
1190@file{sdl-config} can be launched from the MSYS command line.
1191
4c5f7207 1192@item You can install FFmpeg in @file{Program Files/FFmpeg} by typing
ce10ff8e 1193@file{make install}. Do not forget to copy @file{SDL.dll} to the place
4c5f7207 1194you launch @file{ffplay} from.
50f52fcd 1195
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1196@end itemize
1197
115329f1 1198Notes:
988a9f9e 1199@itemize
50f52fcd 1200
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1201@item The target @file{make wininstaller} can be used to create a
1202Nullsoft based Windows installer for FFmpeg and FFplay. @file{SDL.dll}
4c5f7207 1203must be copied to the FFmpeg directory in order to build the
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1204installer.
1205
4c5f7207 1206@item By using @code{./configure --enable-shared} when configuring FFmpeg,
988a9f9e
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1207you can build @file{avcodec.dll} and @file{avformat.dll}. With
1208@code{make install} you install the FFmpeg DLLs and the associated
115329f1 1209headers in @file{Program Files/FFmpeg}.
988a9f9e 1210
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1211@item Visual C++ compatibility: If you used @code{./configure --enable-shared}
1212when configuring FFmpeg, FFmpeg tries to use the Microsoft Visual
988a9f9e 1213C++ @code{lib} tool to build @code{avcodec.lib} and
4c5f7207 1214@code{avformat.lib}. With these libraries you can link your Visual C++
be0efc0c 1215code directly with the FFmpeg DLLs (see below).
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1216
1217@end itemize
b030b284 1218
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1219@subsection Visual C++ compatibility
1220
1221FFmpeg will not compile under Visual C++ -- and it has too many
1222dependencies on the GCC compiler to make a port viable. However,
1223if you want to use the FFmpeg libraries in your own applications,
1224you can still compile those applications using Visual C++. An
1225important restriction to this is that you have to use the
1226dynamically linked versions of the FFmpeg libraries (i.e. the
1227DLLs), and you have to make sure that Visual-C++-compatible
1228import libraries are created during the FFmpeg build process.
1229
1230This description of how to use the FFmpeg libraries with Visual C++ is
1231based on Visual C++ 2005 Express Edition Beta 2. If you have a different
1232version, you might have to modify the procedures slightly.
1233
1234Here are the step-by-step instructions for building the FFmpeg libraries
1235so they can be used with Visual C++:
1236
1237@enumerate
1238
ce10ff8e 1239@item Install Visual C++ (if you have not done so already).
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1240
1241@item Install MinGW and MSYS as described above.
1242
1243@item Add a call to @file{vcvars32.bat} (which sets up the environment
1244variables for the Visual C++ tools) as the first line of
1245@file{msys.bat}. The standard location for @file{vcvars32.bat} is
1246@file{C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat},
1247and the standard location for @file{msys.bat} is
1248@file{C:\msys\1.0\msys.bat}. If this corresponds to your setup, add the
1249following line as the first line of @file{msys.bat}:
1250
1251@code{call "C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat"}
1252
1253@item Start the MSYS shell (file @file{msys.bat}) and type @code{link.exe}.
1254If you get a help message with the command line options of @code{link.exe},
1255this means your environment variables are set up correctly, the
1256Microsoft linker is on the path and will be used by FFmpeg to
1257create Visual-C++-compatible import libraries.
1258
e926e391 1259@item Extract the current version of FFmpeg and change to the FFmpeg directory.
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1260
1261@item Type the command
51d8321d 1262@code{./configure --enable-shared --disable-static --enable-memalign-hack}
ce10ff8e 1263to configure and, if that did not produce any errors,
51d8321d 1264type @code{make} to build FFmpeg.
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1265
1266@item The subdirectories @file{libavformat}, @file{libavcodec}, and
1267@file{libavutil} should now contain the files @file{avformat.dll},
1268@file{avformat.lib}, @file{avcodec.dll}, @file{avcodec.lib},
1269@file{avutil.dll}, and @file{avutil.lib}, respectively. Copy the three
1270DLLs to your System32 directory (typically @file{C:\Windows\System32}).
1271
1272@end enumerate
1273
1274And here is how to use these libraries with Visual C++:
1275
1276@enumerate
1277
1278@item Create a new console application ("File / New / Project") and then
1279select "Win32 Console Application". On the appropriate page of the
1280Application Wizard, uncheck the "Precompiled headers" option.
1281
1282@item Write the source code for your application, or, for testing, just
1283copy the code from an existing sample application into the source file
1284that Visual C++ has already created for you. (Note that your source
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DB
1285filehas to have a @code{.cpp} extension; otherwise, Visual C++ will not
1286compile the FFmpeg headers correctly because in C mode, it does not
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1287recognize the @code{inline} keyword.) For example, you can copy
1288@file{output_example.c} from the FFmpeg distribution (but you will
1289have to make minor modifications so the code will compile under
1290C++, see below).
1291
1292@item Open the "Project / Properties" dialog box. In the "Configuration"
1293combo box, select "All Configurations" so that the changes you make will
1294affect both debug and release builds. In the tree view on the left hand
1295side, select "C/C++ / General", then edit the "Additional Include
1296Directories" setting to contain the complete paths to the
1297@file{libavformat}, @file{libavcodec}, and @file{libavutil}
1298subdirectories of your FFmpeg directory. Note that the directories have
1299to be separated using semicolons. Now select "Linker / General" from the
1300tree view and edit the "Additional Library Directories" setting to
1301contain the same three directories.
1302
1303@item Still in the "Project / Properties" dialog box, select "Linker / Input"
1304from the tree view, then add the files @file{avformat.lib},
1305@file{avcodec.lib}, and @file{avutil.lib} to the end of the "Additional
1306Dependencies". Note that the names of the libraries have to be separated
1307using spaces.
1308
765c3440 1309@item Now, select "C/C++ / Code Generation" from the tree view. Select
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1310"Debug" in the "Configuration" combo box. Make sure that "Runtime
1311Library" is set to "Multi-threaded Debug DLL". Then, select "Release" in
1312the "Configuration" combo box and make sure that "Runtime Library" is
1313set to "Multi-threaded DLL".
1314
1315@item Click "OK" to close the "Project / Properties" dialog box and build
1316the application. Hopefully, it should compile and run cleanly. If you
1317used @file{output_example.c} as your sample application, you will get a
1318few compiler errors, but they are easy to fix. The first type of error
ce10ff8e 1319occurs because Visual C++ does not allow an @code{int} to be converted to
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1320an @code{enum} without a cast. To solve the problem, insert the required
1321casts (this error occurs once for a @code{CodecID} and once for a
1322@code{CodecType}). The second type of error occurs because C++ requires
1323the return value of @code{malloc} to be cast to the exact type of the
1324pointer it is being assigned to. Visual C++ will complain that, for
1325example, @code{(void *)} is being assigned to @code{(uint8_t *)} without
1326an explicit cast. So insert an explicit cast in these places to silence
1327the compiler. The third type of error occurs because the @code{snprintf}
1328library function is called @code{_snprintf} under Visual C++. So just
1329add an underscore to fix the problem. With these changes,
1330@file{output_example.c} should compile under Visual C++, and the
1331resulting executable should produce valid video files.
1332
1333@end enumerate
1334
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1335@subsection Cross compilation for Windows with Linux
1336
1337You must use the MinGW cross compilation tools available at
1338@url{http://www.mingw.org/}.
1339
4c5f7207 1340Then configure FFmpeg with the following options:
b030b284 1341@example
6b74787b 1342./configure --target-os=mingw32 --cross-prefix=i386-mingw32msvc-
b030b284 1343@end example
019c8838 1344(you can change the cross-prefix according to the prefix chosen for the
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1345MinGW tools).
1346
4c5f7207 1347Then you can easily test FFmpeg with Wine
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1348(@url{http://www.winehq.com/}).
1349
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1350@subsection Compilation under Cygwin
1351
1352Cygwin works very much like Unix.
1353
1354Just install your Cygwin with all the "Base" packages, plus the
1355following "Devel" ones:
1356@example
1357binutils, gcc-core, make, subversion
1358@end example
1359
1360Do not install binutils-20060709-1 (they are buggy on shared builds);
1361use binutils-20050610-1 instead.
1362
1363Then run
1364
1365@example
1366./configure --enable-static --disable-shared
1367@end example
1368
1369to make a static build or
1370
1371@example
1372./configure --enable-shared --disable-static
1373@end example
1374
1375to build shared libraries.
1376
1377If you want to build FFmpeg with additional libraries, download Cygwin
1378"Devel" packages for Ogg and Vorbis from any Cygwin packages repository
1379and/or SDL, xvid, faac, faad2 packages from Cygwin Ports,
1380(@url{http://cygwinports.dotsrc.org/}).
1381
1382@subsection Crosscompilation for Windows under Cygwin
1383
ce10ff8e 1384With Cygwin you can create Windows binaries that do not need the cygwin1.dll.
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DB
1385
1386Just install your Cygwin as explained before, plus these additional
1387"Devel" packages:
1388@example
1389gcc-mingw-core, mingw-runtime, mingw-zlib
1390@end example
1391
1392and add some special flags to your configure invocation.
1393
1394For a static build run
1395@example
6b74787b 1396./configure --target-os=mingw32 --enable-memalign-hack --enable-static --disable-shared --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
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1397@end example
1398
1399and for a build with shared libraries
1400@example
6b74787b 1401./configure --target-os=mingw32 --enable-memalign-hack --enable-shared --disable-static --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
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1402@end example
1403
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1404@section BeOS
1405
1406The configure script should guess the configuration itself.
1407Networking support is currently not finished.
1408errno issues fixed by Andrew Bachmann.
1409
1410Old stuff:
1411
7dd611c9 1412François Revol - revol at free dot fr - April 2002
47d944d2 1413
115329f1 1414The configure script should guess the configuration itself,
ce10ff8e 1415however I still did not test building on the net_server version of BeOS.
47d944d2 1416
4c5f7207 1417FFserver is broken (needs poll() implementation).
47d944d2 1418
4c5f7207 1419There are still issues with errno codes, which are negative in BeOS, and
115329f1 1420that FFmpeg negates when returning. This ends up turning errors into
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1421valid results, then crashes.
1422(To be fixed)
1423
34d7008d 1424@chapter Developers Guide
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1425
1426@section API
a0b72f90 1427@itemize @bullet
9181577c 1428@item libavcodec is the library containing the codecs (both encoding and
4c5f7207 1429decoding). Look at @file{libavcodec/apiexample.c} to see how to use it.
9181577c 1430
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1431@item libavformat is the library containing the file format handling (mux and
1432demux code for several formats). Look at @file{ffplay.c} to use it in a
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1433player. See @file{output_example.c} to use it to generate audio or video
1434streams.
1435
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1436@end itemize
1437
1438@section Integrating libavcodec or libavformat in your program
1439
1440You can integrate all the source code of the libraries to link them
1441statically to avoid any version problem. All you need is to provide a
1442'config.mak' and a 'config.h' in the parent directory. See the defines
1443generated by ./configure to understand what is needed.
1444
1445You can use libavcodec or libavformat in your commercial program, but
1446@emph{any patch you make must be published}. The best way to proceed is
4c5f7207 1447to send your patches to the FFmpeg mailing list.
9181577c 1448
80d1c272 1449@node Coding Rules
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1450@section Coding Rules
1451
4c5f7207 1452FFmpeg is programmed in the ISO C90 language with a few additional
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1453features from ISO C99, namely:
1454@itemize @bullet
1455@item
1456the @samp{inline} keyword;
1457@item
1458@samp{//} comments;
1459@item
1460designated struct initializers (@samp{struct s x = @{ .i = 17 @};})
1461@item
114afa9c 1462compound literals (@samp{x = (struct s) @{ 17, 23 @};})
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1463@end itemize
1464
ce10ff8e
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1465These features are supported by all compilers we care about, so we will not
1466accept patches to remove their use unless they absolutely do not impair
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1467clarity and performance.
1468
4c5f7207 1469All code must compile with GCC 2.95 and GCC 3.3. Currently, FFmpeg also
cb6e87c1
FH
1470compiles with several other compilers, such as the Compaq ccc compiler
1471or Sun Studio 9, and we would like to keep it that way unless it would
ce10ff8e 1472be exceedingly involved. To ensure compatibility, please do not use any
4c5f7207 1473additional C99 features or GCC extensions. Especially watch out for:
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FH
1474@itemize @bullet
1475@item
1476mixing statements and declarations;
1477@item
1478@samp{long long} (use @samp{int64_t} instead);
1479@item
1480@samp{__attribute__} not protected by @samp{#ifdef __GNUC__} or similar;
1481@item
019c8838 1482GCC statement expressions (@samp{(x = (@{ int y = 4; y; @})}).
cb6e87c1 1483@end itemize
9181577c 1484
53862e0f 1485Indent size is 4.
b86e38a0 1486The presentation is the one specified by 'indent -i4 -kr -nut'.
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1487The TAB character is forbidden outside of Makefiles as is any
1488form of trailing whitespace. Commits containing either will be
1c1b5a40 1489rejected by the Subversion repository.
9181577c 1490
4c5f7207 1491Main priority in FFmpeg is simplicity and small code size (=less
9181577c
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1492bugs).
1493
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1494Comments: Use the JavaDoc/Doxygen
1495format (see examples below) so that code documentation
1496can be generated automatically. All nontrivial functions should have a comment
ce10ff8e 1497above them explaining what the function does, even if it is just one sentence.
4c5f7207 1498All structures and their member variables should be documented, too.
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1499@example
1500/**
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1501 * @@file mpeg.c
1502 * MPEG codec.
1503 * @@author ...
1504 */
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1505
1506/**
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1507 * Summary sentence.
1508 * more text ...
1509 * ...
1510 */
114afa9c 1511typedef struct Foobar@{
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1512 int var1; /**< var1 description */
1513 int var2; ///< var2 description
1514 /** var3 description */
1515 int var3;
114afa9c 1516@} Foobar;
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1517
1518/**
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MR
1519 * Summary sentence.
1520 * more text ...
1521 * ...
1522 * @@param my_parameter description of my_parameter
1523 * @@return return value description
1524 */
f4888b83
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1525int myfunc(int my_parameter)
1526...
1527@end example
9181577c 1528
115329f1 1529fprintf and printf are forbidden in libavformat and libavcodec,
36d9b4e8
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1530please use av_log() instead.
1531
1c1b5a40 1532@section Development Policy
7a57b90c
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1533
1534@enumerate
115329f1 1535@item
7a57b90c 1536 You must not commit code which breaks FFmpeg! (Meaning unfinished but
4c5f7207 1537 enabled code which breaks compilation or compiles but does not work or
7a57b90c
MN
1538 breaks the regression tests)
1539 You can commit unfinished stuff (for testing etc), but it must be disabled
1540 (#ifdef etc) by default so it does not interfere with other developers'
1541 work.
115329f1 1542@item
ce10ff8e 1543 You do not have to over-test things. If it works for you, and you think it
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DB
1544 should work for others, then commit. If your code has problems
1545 (portability, triggers compiler bugs, unusual environment etc) they will be
7a57b90c 1546 reported and eventually fixed.
115329f1 1547@item
7a57b90c 1548 Do not commit unrelated changes together, split them into self-contained
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DB
1549 pieces. Also do not forget that if part B depends on part A, but A does not
1550 depend on B, then A can and should be committed first and separate from B.
1551 Keeping changes well split into self-contained parts makes reviewing and
1552 understanding them on the commit log mailing list easier. This also helps
1553 in case of debugging later on.
1554 Also if you have doubts about splitting or not splitting, do not hesitate to
442d1598 1555 ask/discuss it on the developer mailing list.
7a57b90c
MN
1556@item
1557 Do not change behavior of the program (renaming options etc) without
019c8838 1558 first discussing it on the ffmpeg-devel mailing list. Do not remove
7a57b90c 1559 functionality from the code. Just improve!
115329f1 1560
4c5f7207 1561 Note: Redundant code can be removed.
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1562@item
1563 Do not commit changes to the build system (Makefiles, configure script)
019c8838 1564 which change behavior, defaults etc, without asking first. The same
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1565 applies to compiler warning fixes, trivial looking fixes and to code
1566 maintained by other developers. We usually have a reason for doing things
019c8838 1567 the way we do. Send your changes as patches to the ffmpeg-devel mailing
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1568 list, and if the code maintainers say OK, you may commit. This does not
1569 apply to files you wrote and/or maintain.
1570@item
1571 We refuse source indentation and other cosmetic changes if they are mixed
1572 with functional changes, such commits will be rejected and removed. Every
1573 developer has his own indentation style, you should not change it. Of course
1574 if you (re)write something, you can use your own style, even though we would
4c5f7207 1575 prefer if the indentation throughout FFmpeg was consistent (Many projects
ce10ff8e 1576 force a given indentation style - we do not.). If you really need to make
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1577 indentation changes (try to avoid this), separate them strictly from real
1578 changes.
1579
114afa9c 1580 NOTE: If you had to put if()@{ .. @} over a large (> 5 lines) chunk of code,
ce10ff8e 1581 then either do NOT change the indentation of the inner part within (do not
019c8838 1582 move it to the right)! or do so in a separate commit
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1583@item
1584 Always fill out the commit log message. Describe in a few lines what you
1585 changed and why. You can refer to mailing list postings if you fix a
1586 particular bug. Comments such as "fixed!" or "Changed it." are unacceptable.
1587@item
1588 If you apply a patch by someone else, include the name and email address in
1c1b5a40 1589 the log message. Since the ffmpeg-cvslog mailing list is publicly
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1590 archived you should add some SPAM protection to the email address. Send an
1591 answer to ffmpeg-devel (or wherever you got the patch from) saying that
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1592 you applied the patch.
1593@item
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1594 When applying patches that have been discussed (at length) on the mailing
1595 list, reference the thread in the log message.
1596@item
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1597 Do NOT commit to code actively maintained by others without permission.
1598 Send a patch to ffmpeg-devel instead. If noone answers within a reasonable
1599 timeframe (12h for build failures and security fixes, 3 days small changes,
ce10ff8e 1600 1 week for big patches) then commit your patch if you think it is OK.
5ab0f204 1601 Also note, the maintainer can simply ask for more time to review!
7a57b90c 1602@item
1c1b5a40 1603 Subscribe to the ffmpeg-cvslog mailing list. The diffs of all commits
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1604 are sent there and reviewed by all the other developers. Bugs and possible
1605 improvements or general questions regarding commits are discussed there. We
1606 expect you to react if problems with your code are uncovered.
1607@item
1608 Update the documentation if you change behavior or add features. If you are
019c8838 1609 unsure how best to do this, send a patch to ffmpeg-devel, the documentation
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1610 maintainer(s) will review and commit your stuff.
1611@item
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1612 Try to keep important discussions and requests (also) on the public
1613 developer mailing list, so that all developers can benefit from them.
1614@item
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1615 Never write to unallocated memory, never write over the end of arrays,
1616 always check values read from some untrusted source before using them
1617 as array index or other risky things.
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1618@item
1619 Remember to check if you need to bump versions for the specific libav
f0efbde7 1620 parts (libavutil, libavcodec, libavformat) you are changing. You need
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1621 to change the version integer and the version string.
1622 Incrementing the first component means no backward compatibility to
a940b428 1623 previous versions (e.g. removal of a function from the public API).
76bec1d8 1624 Incrementing the second component means backward compatible change
a940b428 1625 (e.g. addition of a function to the public API).
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1626 Incrementing the third component means a noteworthy binary compatible
1627 change (e.g. encoder bug fix that matters for the decoder).
ebd32fd7 1628@item
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1629 If you add a new codec, remember to update the changelog, add it to
1630 the supported codecs table in the documentation and bump the second
1631 component of the @file{libavcodec} version number appropriately. If
1632 it has a fourcc, add it to @file{libavformat/avienc.c}, even if it
1633 is only a decoder.
65d0bea8 1634@item
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1635 Do not change code to hide warnings without ensuring that the underlying
1636 logic is correct and thus the warning was inappropriate.
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1637@item
1638 If you add a new file, give it a proper license header. Do not copy and
1639 paste it from a random place, use an existing file as template.
114afa9c 1640@end enumerate
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1641
1642We think our rules are not too hard. If you have comments, contact us.
1643
1644Note, these rules are mostly borrowed from the MPlayer project.
1645
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1646@section Submitting patches
1647
ce10ff8e 1648First, (@pxref{Coding Rules}) above if you did not yet.
80d1c272 1649
6a6810b1 1650When you submit your patch, try to send a unified diff (diff '-up'
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1651option). I cannot read other diffs :-)
1652
6e5c1877 1653Also please do not submit patches which contain several unrelated changes.
115329f1 1654Split them into individual self-contained patches; this makes reviewing
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1655them much easier.
1656
9181577c 1657Run the regression tests before submitting a patch so that you can
6bf40f39 1658verify that there are no big problems.
9181577c 1659
9181577c 1660Patches should be posted as base64 encoded attachments (or any other
ce10ff8e 1661encoding which ensures that the patch will not be trashed during
115329f1 1662transmission) to the ffmpeg-devel mailing list, see
2b165e29 1663@url{http://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel}
9181577c 1664
54fcf429 1665It also helps quite a bit if you tell us what the patch does (for example
4c5f7207 1666'replaces lrint by lrintf'), and why (for example '*BSD isn't C99 compliant
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1667and has no lrint()')
1668
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1669Also please if you send several patches, send each patch as separate mail,
1670do not attach several unrelated patches to the same mail.
a15bcf70 1671
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1672@section patch submission checklist
1673
1674@enumerate
1675@item
1676 Do the regression tests pass with the patch applied?
1677@item
1678 Is the patch a unified diff?
1679@item
4a7a0908 1680 Is the patch against latest FFmpeg SVN?
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1681@item
1682 Are you subscribed to ffmpeg-dev?
1683 (the list is subscribers only due to spam)
1684@item
1685 Have you checked that the changes are minimal, so that the same cannot be
442d1598 1686 achieved with a smaller patch and/or simpler final code?
dd597cd7 1687@item
4a7a0908 1688 If the change is to speed critical code, did you benchmark it?
dd597cd7 1689@item
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1690 If you did any benchmarks, did you provide them in the mail?
1691@item
442d1598 1692 Have you checked that the patch does not introduce buffer overflows or
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1693 other security issues?
1694@item
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1695 Is the patch created from the root of the source tree, so it can be
1696 applied with @code{patch -p0}?
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1697@item
1698 Does the patch not mix functional and cosmetic changes?
1699@item
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1700 Did you add tabs or trailing whitespace to the code? Both are forbidden.
1701@item
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1702 Is the patch attached to the email you send?
1703@item
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1704 Is the mime type of the patch correct? It should be text/x-diff or
1705 text/x-patch or at least text/plain and not application/octet-stream.
dd597cd7 1706@item
4a7a0908 1707 If the patch fixes a bug, did you provide a verbose analysis of the bug?
dd597cd7 1708@item
4a7a0908 1709 If the patch fixes a bug, did you provide enough information, including
dd597cd7 1710 a sample, so the bug can be reproduced and the fix can be verified?
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1711 Note please do not attach samples >100k to mails but rather provide a
1712 URL, you can upload to ftp://upload.mplayerhq.hu
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1713@item
1714 Did you provide a verbose summary about what the patch does change?
1715@item
1716 Did you provide a verbose explanation why it changes things like it does?
1717@item
442d1598 1718 Did you provide a verbose summary of the user visible advantages and
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1719 disadvantages if the patch is applied?
1720@item
1721 Did you provide an example so we can verify the new feature added by the
1722 patch easily?
1723@item
bbe94afb 1724 If you added a new file, did you insert a license header? It should be
6baa2943 1725 taken from FFmpeg, not randomly copied and pasted from somewhere else.
6e4bc6ee 1726@item
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1727 You should maintain alphabetical order in alphabetically ordered lists as
1728 long as doing so does not break API/ABI compatibility.
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1729@item
1730 Did you provide a suggestion for a clear commit log message?
dd597cd7
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1731@end enumerate
1732
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1733@section Patch review process
1734
1735All patches posted to ffmpeg-devel will be reviewed, unless they contain a
1736clear note that the patch is not for SVN.
1737Reviews and comments will be posted as replies to the patch on the
ce10ff8e 1738mailing list. The patch submitter then has to take care of every comment,
442d1598 1739that can be by resubmitting a changed patch or by discussion. Resubmitted
ce10ff8e 1740patches will themselves be reviewed like any other patch. If at some point
f5f11d71 1741a patch passes review with no comments then it is approved, that can for
ce10ff8e 1742simple and small patches happen immediately while large patches will generally
f5f11d71 1743have to be changed and reviewed many times before they are approved.
ce10ff8e 1744After a patch is approved it will be committed to the repository.
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1745
1746We will review all submitted patches, but sometimes we are quite busy so
1747especially for large patches this can take several weeks.
1748
1749When resubmitting patches, please do not make any significant changes
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1750not related to the comments received during review. Such patches will
1751be rejected. Instead, submit significant changes or new features as
1752separate patches.
cf7f2b16 1753
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1754@section Regression tests
1755
1c1b5a40 1756Before submitting a patch (or committing to the repository), you should at least
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1757test that you did not break anything.
1758
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1759The regression tests build a synthetic video stream and a synthetic
1760audio stream. These are then encoded and decoded with all codecs or
9181577c 1761formats. The CRC (or MD5) of each generated file is recorded in a
4c5f7207 1762result file. A 'diff' is launched to compare the reference results and
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1763the result file.
1764
4c5f7207 1765The regression tests then go on to test the FFserver code with a
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1766limited set of streams. It is important that this step runs correctly
1767as well.
1768
36d9b4e8 1769Run 'make test' to test all the codecs and formats.
9181577c 1770
4c5f7207 1771Run 'make fulltest' to test all the codecs, formats and FFserver.
9181577c 1772
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1773[Of course, some patches may change the results of the regression tests. In
1774this case, the reference results of the regression tests shall be modified
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1775accordingly].
1776
1777@bye