correct comment about seek function
[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
cc58300e 47ffmpeg -f x11grab -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
cc58300e 54ffmpeg -f x11grab -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
5438308f 130ffmpeg -i snatch_1.vob -f avi -vcodec mpeg4 -b 800k -g 300 -bf 2 -acodec mp3 -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
138to enable LAME support by passing @code{--enable-mp3lame} to configure.
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
311@end table
312
313@item -aspect aspect
4c5f7207 314Set aspect ratio (4:3, 16:9 or 1.3333, 1.7777).
18bff752 315@item -croptop size
4c5f7207 316Set top crop band size (in pixels).
18bff752 317@item -cropbottom size
4c5f7207 318Set bottom crop band size (in pixels).
18bff752 319@item -cropleft size
4c5f7207 320Set left crop band size (in pixels).
18bff752 321@item -cropright size
4c5f7207 322Set right crop band size (in pixels).
1ff93ffc 323@item -padtop size
4c5f7207 324Set top pad band size (in pixels).
1ff93ffc 325@item -padbottom size
4c5f7207 326Set bottom pad band size (in pixels).
1ff93ffc 327@item -padleft size
4c5f7207 328Set left pad band size (in pixels).
1ff93ffc 329@item -padright size
4c5f7207 330Set right pad band size (in pixels).
5b79a73e 331@item -padcolor (hex color)
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332Set color of padded bands. The value for padcolor is expressed
333as a six digit hexadecimal number where the first two digits
334represent red, the middle two digits green and last two digits
335blue (default = 000000 (black)).
9181577c 336@item -vn
4c5f7207 337Disable video recording.
115329f1 338@item -bt tolerance
dc5ee8bc 339Set video bitrate tolerance (in bit/s).
18bff752 340@item -maxrate bitrate
a5515106 341Set max video bitrate tolerance (in bit/s).
18bff752 342@item -minrate bitrate
a5515106 343Set min video bitrate tolerance (in bit/s).
18bff752 344@item -bufsize size
81d0618f 345Set rate control buffer size (in bits).
115329f1 346@item -vcodec codec
4c5f7207 347Force video codec to @var{codec}. Use the @code{copy} special value to
5ee03c86 348tell that the raw codec data must be copied as is.
18bff752 349@item -sameq
4c5f7207 350Use same video quality as source (implies VBR).
9181577c 351
115329f1 352@item -pass n
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353Select the pass number (1 or 2). It is useful to do two pass
354encoding. The statistics of the video are recorded in the first
355pass and the video is generated at the exact requested bitrate
356in the second pass.
9181577c 357
115329f1 358@item -passlogfile file
4c5f7207 359Set two pass logfile name to @var{file}.
9181577c 360
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361@item -newvideo
362Add a new video stream to the current output stream.
363
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364@end table
365
18bff752 366@section Advanced Video Options
9181577c 367
e99c4e10 368@table @option
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369@item -pix_fmt format
370Set pixel format.
115329f1 371@item -g gop_size
4c5f7207 372Set the group of pictures size.
115329f1 373@item -intra
4c5f7207 374Use only intra frames.
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375@item -vdt n
376Discard threshold.
115329f1 377@item -qscale q
4bef236b 378Use fixed video quantizer scale (VBR).
115329f1 379@item -qmin q
4bef236b 380minimum video quantizer scale (VBR)
115329f1 381@item -qmax q
4bef236b 382maximum video quantizer scale (VBR)
115329f1 383@item -qdiff q
4bef236b 384maximum difference between the quantizer scales (VBR)
115329f1 385@item -qblur blur
4bef236b 386video quantizer scale blur (VBR)
115329f1 387@item -qcomp compression
4bef236b 388video quantizer scale compression (VBR)
18bff752 389
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390@item -lmin lambda
391minimum video lagrange factor (VBR)
392@item -lmax lambda
393max video lagrange factor (VBR)
394@item -mblmin lambda
395minimum macroblock quantizer scale (VBR)
396@item -mblmax lambda
397maximum macroblock quantizer scale (VBR)
398
399These four options (lmin, lmax, mblmin, mblmax) use 'lambda' units,
400but you may use the QP2LAMBDA constant to easily convert from 'q' units:
401@example
402ffmpeg -i src.ext -lmax 21*QP2LAMBDA dst.ext
403@end example
404
18bff752 405@item -rc_init_cplx complexity
4c5f7207 406initial complexity for single pass encoding
18bff752 407@item -b_qfactor factor
4c5f7207 408qp factor between P- and B-frames
18bff752 409@item -i_qfactor factor
4c5f7207 410qp factor between P- and I-frames
18bff752 411@item -b_qoffset offset
4c5f7207 412qp offset between P- and B-frames
18bff752 413@item -i_qoffset offset
4c5f7207 414qp offset between P- and I-frames
18bff752 415@item -rc_eq equation
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416Set rate control equation (@pxref{FFmpeg formula
417evaluator}) (default = @code{tex^qComp}).
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418@item -rc_override override
419rate control override for specific intervals
18bff752 420@item -me method
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421Set motion estimation method to @var{method}.
422Available methods are (from lowest to best quality):
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423@table @samp
424@item zero
5ee03c86 425Try just the (0, 0) vector.
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426@item phods
427@item log
428@item x1
429@item epzs
430(default method)
431@item full
432exhaustive search (slow and marginally better than epzs)
433@end table
434
435@item -dct_algo algo
4c5f7207 436Set DCT algorithm to @var{algo}. Available values are:
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437@table @samp
438@item 0
439FF_DCT_AUTO (default)
440@item 1
441FF_DCT_FASTINT
442@item 2
443FF_DCT_INT
444@item 3
445FF_DCT_MMX
446@item 4
447FF_DCT_MLIB
448@item 5
449FF_DCT_ALTIVEC
450@end table
451
452@item -idct_algo algo
4c5f7207 453Set IDCT algorithm to @var{algo}. Available values are:
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454@table @samp
455@item 0
456FF_IDCT_AUTO (default)
457@item 1
115329f1 458FF_IDCT_INT
18bff752 459@item 2
115329f1 460FF_IDCT_SIMPLE
18bff752 461@item 3
115329f1 462FF_IDCT_SIMPLEMMX
18bff752 463@item 4
115329f1 464FF_IDCT_LIBMPEG2MMX
18bff752 465@item 5
115329f1 466FF_IDCT_PS2
18bff752 467@item 6
115329f1 468FF_IDCT_MLIB
18bff752 469@item 7
115329f1 470FF_IDCT_ARM
18bff752 471@item 8
115329f1 472FF_IDCT_ALTIVEC
18bff752 473@item 9
115329f1 474FF_IDCT_SH4
18bff752 475@item 10
115329f1 476FF_IDCT_SIMPLEARM
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477@end table
478
479@item -er n
4c5f7207 480Set error resilience to @var{n}.
18bff752 481@table @samp
115329f1 482@item 1
1471c6c2 483FF_ER_CAREFUL (default)
18bff752 484@item 2
5ee03c86 485FF_ER_COMPLIANT
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486@item 3
487FF_ER_AGGRESSIVE
488@item 4
489FF_ER_VERY_AGGRESSIVE
490@end table
491
5ee03c86 492@item -ec bit_mask
4c5f7207 493Set error concealment to @var{bit_mask}. @var{bit_mask} is a bit mask of
5ee03c86 494the following values:
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495@table @samp
496@item 1
4c5f7207 497FF_EC_GUESS_MVS (default = enabled)
18bff752 498@item 2
4c5f7207 499FF_EC_DEBLOCK (default = enabled)
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500@end table
501
502@item -bf frames
4c5f7207 503Use 'frames' B-frames (supported for MPEG-1, MPEG-2 and MPEG-4).
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504@item -mbd mode
505macroblock decision
506@table @samp
507@item 0
4c5f7207 508FF_MB_DECISION_SIMPLE: Use mb_cmp (cannot change it yet in FFmpeg).
18bff752 509@item 1
4c5f7207 510FF_MB_DECISION_BITS: Choose the one which needs the fewest bits.
18bff752 511@item 2
019c8838 512FF_MB_DECISION_RD: rate distortion
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513@end table
514
515@item -4mv
4c5f7207 516Use four motion vector by macroblock (MPEG-4 only).
18bff752 517@item -part
4c5f7207 518Use data partitioning (MPEG-4 only).
18bff752 519@item -bug param
4c5f7207 520Work around encoder bugs that are not auto-detected.
18bff752 521@item -strict strictness
4c5f7207 522How strictly to follow the standards.
5ee03c86 523@item -aic
4c5f7207 524Enable Advanced intra coding (h263+).
5ee03c86 525@item -umv
4c5f7207 526Enable Unlimited Motion Vector (h263+)
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527
528@item -deinterlace
4c5f7207 529Deinterlace pictures.
3841e813 530@item -ilme
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531Force interlacing support in encoder (MPEG-2 and MPEG-4 only).
532Use this option if your input file is interlaced and you want
533to keep the interlaced format for minimum losses.
534The alternative is to deinterlace the input stream with
535@option{-deinterlace}, but deinterlacing introduces losses.
18bff752 536@item -psnr
4c5f7207 537Calculate PSNR of compressed frames.
18bff752 538@item -vstats
4c5f7207 539Dump video coding statistics to @file{vstats_HHMMSS.log}.
18bff752 540@item -vhook module
4c5f7207 541Insert video processing @var{module}. @var{module} contains the module
18bff752 542name and its parameters separated by spaces.
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543@item -top n
544top=1/bottom=0/auto=-1 field first
545@item -dc precision
546Intra_dc_precision.
547@item -vtag fourcc/tag
548Force video tag/fourcc.
549@item -qphist
550Show QP histogram.
551@item -vbsf bitstream filter
552Bitstream filters available are "dump_extra", "remove_extra", "noise".
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553@end table
554
555@section Audio Options
556
557@table @option
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558@item -aframes number
559Set the number of audio frames to record.
115329f1 560@item -ar freq
4c5f7207 561Set the audio sampling frequency (default = 44100 Hz).
115329f1 562@item -ab bitrate
5438308f 563Set the audio bitrate in bit/s (default = 64k).
18bff752 564@item -ac channels
4c5f7207 565Set the number of audio channels (default = 1).
5ee03c86 566@item -an
4c5f7207 567Disable audio recording.
5ee03c86 568@item -acodec codec
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569Force audio codec to @var{codec}. Use the @code{copy} special value to
570specify that the raw codec data must be copied as is.
de62a89d 571@item -newaudio
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572Add a new audio track to the output file. If you want to specify parameters,
573do so before @code{-newaudio} (@code{-acodec}, @code{-ab}, etc..).
de62a89d 574
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575Mapping will be done automatically, if the number of output streams is equal to
576the number of input streams, else it will pick the first one that matches. You
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577can override the mapping using @code{-map} as usual.
578
579Example:
580@example
5438308f 581ffmpeg -i file.mpg -vcodec copy -acodec ac3 -ab 384k test.mpg -acodec mp2 -ab 192k -newaudio
de62a89d 582@end example
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583@item -alang code
584Set the ISO 639 language code (3 letters) of the current audio stream.
585@end table
586
587@section Advanced Audio options:
588
589@table @option
590@item -atag fourcc/tag
591Force audio tag/fourcc.
592@item -absf bitstream filter
593Bitstream filters available are "dump_extra", "remove_extra", "noise", "mp3comp", "mp3decomp".
594@end table
595
596@section Subtitle options:
597
598@table @option
599@item -scodec codec
600Force subtitle codec ('copy' to copy stream).
601@item -newsubtitle
602Add a new subtitle stream to the current output stream.
603@item -slang code
604Set the ISO 639 language code (3 letters) of the current subtitle stream.
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605@end table
606
607@section Audio/Video grab options
608
609@table @option
18bff752 610@item -vc channel
4c5f7207 611Set video grab channel (DV1394 only).
18bff752 612@item -tvstd standard
4c5f7207 613Set television standard (NTSC, PAL (SECAM)).
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614@item -isync
615Synchronize read on input.
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616@end table
617
618@section Advanced options
619
620@table @option
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621@item -map input stream id[:input stream id]
622Set stream mapping from input streams to output streams.
623Just enumerate the input streams in the order you want them in the output.
624[input stream id] sets the (input) stream to sync against.
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625@item -map_meta_data outfile:infile
626Set meta data information of outfile from infile.
18bff752 627@item -debug
4c5f7207 628Print specific debug info.
115329f1 629@item -benchmark
4c5f7207 630Add timings for benchmarking.
4386f941 631@item -dump
4c5f7207 632Dump each input packet.
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633@item -hex
634When dumping packets, also dump the payload.
18bff752 635@item -bitexact
4c5f7207 636Only use bit exact algorithms (for codec testing).
18bff752 637@item -ps size
4c5f7207 638Set packet size in bits.
5ee03c86 639@item -re
4c5f7207 640Read input at native frame rate. Mainly used to simulate a grab device.
4386f941 641@item -loop_input
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642Loop over the input stream. Currently it works only for image
643streams. This option is used for automatic FFserver testing.
8108551a 644@item -loop_output number_of_times
019c8838 645Repeatedly loop output for formats that support looping such as animated GIF
4c5f7207 646(0 will loop the output infinitely).
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647@item -threads count
648Thread count.
c52e13f1 649@item -vsync parameter
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650Video sync method. Video will be stretched/squeezed to match the timestamps,
651it is done by duplicating and dropping frames. With -map you can select from
652which stream the timestamps should be taken. You can leave either video or
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653audio unchanged and sync the remaining stream(s) to the unchanged one.
654@item -async samples_per_second
29c9183c 655Audio sync method. "Stretches/squeezes" the audio stream to match the timestamps,
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656the parameter is the maximum samples per second by which the audio is changed.
657-async 1 is a special case where only the start of the audio stream is corrected
658without any later correction.
9181577c 659@end table
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660
661@node FFmpeg formula evaluator
662@section FFmpeg formula evaluator
663
664When evaluating a rate control string, FFmpeg uses an internal formula
115329f1 665evaluator.
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666
667The following binary operators are available: @code{+}, @code{-},
668@code{*}, @code{/}, @code{^}.
669
670The following unary operators are available: @code{+}, @code{-},
671@code{(...)}.
672
673The following functions are available:
674@table @var
675@item sinh(x)
676@item cosh(x)
677@item tanh(x)
678@item sin(x)
679@item cos(x)
680@item tan(x)
681@item exp(x)
682@item log(x)
683@item squish(x)
684@item gauss(x)
685@item abs(x)
686@item max(x, y)
687@item min(x, y)
688@item gt(x, y)
689@item lt(x, y)
690@item eq(x, y)
691@item bits2qp(bits)
692@item qp2bits(qp)
693@end table
694
695The following constants are available:
696@table @var
697@item PI
698@item E
699@item iTex
700@item pTex
701@item tex
702@item mv
703@item fCode
704@item iCount
705@item mcVar
706@item var
707@item isI
708@item isP
709@item isB
710@item avgQP
711@item qComp
712@item avgIITex
713@item avgPITex
714@item avgPPTex
715@item avgBPTex
716@item avgTex
717@end table
718
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719@c man end
720
721@ignore
722
723@setfilename ffmpeg
724@settitle FFmpeg video converter
725
726@c man begin SEEALSO
019c8838 727ffserver(1), ffplay(1) and the HTML documentation of @file{ffmpeg}.
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728@c man end
729
730@c man begin AUTHOR
731Fabrice Bellard
732@c man end
733
734@end ignore
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735
736@section Protocols
737
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738The filename can be @file{-} to read from standard input or to write
739to standard output.
9181577c 740
4c5f7207 741FFmpeg also handles many protocols specified with an URL syntax.
9181577c 742
4c5f7207 743Use 'ffmpeg -formats' to see a list of the supported protocols.
9181577c 744
e99c4e10 745The protocol @code{http:} is currently used only to communicate with
4c5f7207 746FFserver (see the FFserver documentation). When FFmpeg will be a
e99c4e10 747video player it will also be used for streaming :-)
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748
749@chapter Tips
750
751@itemize
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752@item For streaming at very low bitrate application, use a low frame rate
753and a small GOP size. This is especially true for RealVideo where
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754the Linux player does not seem to be very fast, so it can miss
755frames. An example is:
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756
757@example
3c0ba870 758ffmpeg -g 3 -r 3 -t 10 -b 50k -s qcif -f rv10 /tmp/b.rm
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759@end example
760
761@item The parameter 'q' which is displayed while encoding is the current
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762quantizer. The value 1 indicates that a very good quality could
763be achieved. The value 31 indicates the worst quality. If q=31 appears
e99c4e10 764too often, it means that the encoder cannot compress enough to meet
4c5f7207 765your bitrate. You must either increase the bitrate, decrease the
e99c4e10 766frame rate or decrease the frame size.
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767
768@item If your computer is not fast enough, you can speed up the
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769compression at the expense of the compression ratio. You can use
770'-me zero' to speed up motion estimation, and '-intra' to disable
4c5f7207 771motion estimation completely (you have only I-frames, which means it
e99c4e10 772is about as good as JPEG compression).
9181577c 773
4c5f7207 774@item To have very low audio bitrates, reduce the sampling frequency
019c8838 775(down to 22050 kHz for MPEG audio, 22050 or 11025 for AC3).
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776
777@item To have a constant quality (but a variable bitrate), use the option
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778'-qscale n' when 'n' is between 1 (excellent quality) and 31 (worst
779quality).
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780
781@item When converting video files, you can use the '-sameq' option which
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782uses the same quality factor in the encoder as in the decoder.
783It allows almost lossless encoding.
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784
785@end itemize
786
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787
788@chapter external libraries
789
790FFmpeg can be hooked up with a number of external libraries to add support
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791for more formats. None of them are used by default, their use has to be
792explicitly requested by passing the appropriate flags to @file{./configure}.
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793
794@section AMR
795
796AMR comes in two different flavors, WB and NB. FFmpeg can make use of the
797AMR WB (floating-point mode) and the AMR NB (both floating-point and
798fixed-point mode) reference decoders and encoders.
799
800@itemize
801
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802@item For AMR WB floating-point and AMR NB floating point support, go to
803@url{http://www.penguin.cz/~utx/amr} and follow the instructions for building
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804the libraries. Pass @code{--enable-amr-nb} and/or @code{--enable-amr-wb} to
805configure to enable the libraries.
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806
807@item For AMR NB fixed-point download TS26.073 REL-6 V6.0.0 from
808@url{http://www.3gpp.org/ftp/Specs/archive/26_series/26.073/26073-600.zip}
809and extract the source to the directory @file{libavcodec/amr}.
ef4e31d4 810You must also add @code{-DMMS_IO} to @code{CFLAGS} in
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811@file{libavcodec/amr/makefile}, i.e.
812``@code{CFLAGS = -Wall -pedantic-errors -I. $(CFLAGS_$(MODE)) -D$(VAD) -DMMS_IO}''.
4f99f932 813Pass @code{--enable-amr-nb-fixed} to configure to enable it.
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814
815@end itemize
816
817
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818@chapter Supported File Formats and Codecs
819
820You can use the @code{-formats} option to have an exhaustive list.
821
822@section File Formats
823
6bf40f39 824FFmpeg supports the following file formats through the @code{libavformat}
0699d2fe 825library:
9181577c 826
3fc9e78f 827@multitable @columnfractions .4 .1 .1 .4
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828@item Supported File Format @tab Encoding @tab Decoding @tab Comments
829@item MPEG audio @tab X @tab X
4c5f7207 830@item MPEG-1 systems @tab X @tab X
9181577c 831@tab muxed audio and video
4c5f7207 832@item MPEG-2 PS @tab X @tab X
9181577c 833@tab also known as @code{VOB} file
4c5f7207 834@item MPEG-2 TS @tab @tab X
9181577c 835@tab also known as DVB Transport Stream
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836@item ASF@tab X @tab X
837@item AVI@tab X @tab X
838@item WAV@tab X @tab X
9181577c 839@item Macromedia Flash@tab X @tab X
4c5f7207 840@tab Only embedded audio is decoded.
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841@item FLV @tab X @tab X
842@tab Macromedia Flash video files
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843@item Real Audio and Video @tab X @tab X
844@item Raw AC3 @tab X @tab X
845@item Raw MJPEG @tab X @tab X
846@item Raw MPEG video @tab X @tab X
847@item Raw PCM8/16 bits, mulaw/Alaw@tab X @tab X
848@item Raw CRI ADX audio @tab X @tab X
849@item Raw Shorten audio @tab @tab X
850@item SUN AU format @tab X @tab X
7fe4c823 851@item NUT @tab X @tab X @tab NUT Open Container Format
115329f1 852@item QuickTime @tab X @tab X
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853@item MPEG-4 @tab X @tab X
854@tab MPEG-4 is a variant of QuickTime.
115329f1 855@item Raw MPEG4 video @tab X @tab X
4fa1c4fa 856@item DV @tab X @tab X
701b603d 857@item 4xm @tab @tab X
4c5f7207 858@tab 4X Technologies format, used in some games.
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859@item Playstation STR @tab @tab X
860@item Id RoQ @tab @tab X
4c5f7207 861@tab Used in Quake III, Jedi Knight 2, other computer games.
4d3b1f8d 862@item Interplay MVE @tab @tab X
4c5f7207 863@tab Format used in various Interplay computer games.
b17e9c99 864@item WC3 Movie @tab @tab X
4c5f7207 865@tab Multimedia format used in Origin's Wing Commander III computer game.
2fdf638b 866@item Sega FILM/CPK @tab @tab X
4c5f7207 867@tab Used in many Sega Saturn console games.
2fdf638b 868@item Westwood Studios VQA/AUD @tab @tab X
4c5f7207 869@tab Multimedia formats used in Westwood Studios games.
4120a53a 870@item Id Cinematic (.cin) @tab @tab X
4c5f7207 871@tab Used in Quake II.
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872@item FLIC format @tab @tab X
873@tab .fli/.flc files
da00f30e 874@item Sierra VMD @tab @tab X
4c5f7207 875@tab Used in Sierra CD-ROM games.
d08d7142 876@item Sierra Online @tab @tab X
4c5f7207 877@tab .sol files used in Sierra Online games.
38088adf 878@item Matroska @tab @tab X
ad81a9fe 879@item Electronic Arts Multimedia @tab @tab X
4c5f7207 880@tab Used in various EA games; files have extensions like WVE and UV2.
353147ed 881@item Nullsoft Video (NSV) format @tab @tab X
4accd1fd 882@item ADTS AAC audio @tab X @tab X
ea395e8c 883@item Creative VOC @tab X @tab X @tab Created for the Sound Blaster Pro.
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884@item American Laser Games MM @tab @tab X
885@tab Multimedia format used in games like Mad Dog McCree
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886@item AVS @tab @tab X
887@tab Multimedia format used by the Creature Shock game.
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888@item Smacker @tab @tab X
889@tab Multimedia format used by many games.
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890@item GXF @tab X @tab X
891@tab General eXchange Format SMPTE 360M, used by Thomson Grass Valley playout servers.
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892@item CIN @tab @tab X
893@tab Multimedia format used by Delphine Software games.
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894@item MXF @tab @tab X
895@tab Material eXchange Format SMPTE 377M, used by D-Cinema, broadcast industry.
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896@item SEQ @tab @tab X
897@tab Tiertex .seq files used in the DOS CDROM version of the game Flashback.
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898@item DXA @tab @tab X
899@tab This format is used in non-Windows version of Feeble Files game and
900different game cutscenes repacked for use with ScummVM.
efb0c399 901@item THP @tab @tab X
d1e0d21f 902@tab Used on the Nintendo GameCube.
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903@item C93 @tab @tab X
904@tab Used in the game Cyberia from Interplay.
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905@item Bethsoft VID @tab @tab X
906@tab Used in some games from Bethesda Softworks.
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907@item CRYO APC @tab @tab X
908@tab Audio format used in some games by CRYO Interactive Entertainment.
353147ed 909@end multitable
9181577c 910
4c5f7207 911@code{X} means that encoding (resp. decoding) is supported.
9181577c 912
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913@section Image Formats
914
915FFmpeg can read and write images for each frame of a video sequence. The
916following image formats are supported:
917
3fc9e78f 918@multitable @columnfractions .4 .1 .1 .4
0699d2fe 919@item Supported Image Format @tab Encoding @tab Decoding @tab Comments
115329f1 920@item PGM, PPM @tab X @tab X
4c5f7207 921@item PAM @tab X @tab X @tab PAM is a PNM extension with alpha support.
2eb5d024 922@item PGMYUV @tab X @tab X @tab PGM with U and V components in YUV 4:2:0
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923@item JPEG @tab X @tab X @tab Progressive JPEG is not supported.
924@item .Y.U.V @tab X @tab X @tab one raw file per component
925@item animated GIF @tab X @tab X @tab Only uncompressed GIFs are generated.
926@item PNG @tab X @tab X @tab 2 bit and 4 bit/pixel not supported yet.
3689cf16 927@item Targa @tab @tab X @tab Targa (.TGA) image format.
716222db 928@item TIFF @tab X @tab X @tab YUV, JPEG and some extension is not supported yet.
6a91ec51 929@item SGI @tab X @tab X @tab SGI RGB image format
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930@end multitable
931
4c5f7207 932@code{X} means that encoding (resp. decoding) is supported.
0699d2fe 933
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934@section Video Codecs
935
3fc9e78f 936@multitable @columnfractions .4 .1 .1 .4
9181577c 937@item Supported Codec @tab Encoding @tab Decoding @tab Comments
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938@item MPEG-1 video @tab X @tab X
939@item MPEG-2 video @tab X @tab X
2bc5da7b 940@item MPEG-4 @tab X @tab X
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941@item MSMPEG4 V1 @tab X @tab X
942@item MSMPEG4 V2 @tab X @tab X
2bc5da7b 943@item MSMPEG4 V3 @tab X @tab X
9181577c 944@item WMV7 @tab X @tab X
4c5f7207 945@item WMV8 @tab X @tab X @tab not completely working
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946@item WMV9 @tab @tab X @tab not completely working
947@item VC1 @tab @tab X
b06b45c4 948@item H.261 @tab X @tab X
4c5f7207 949@item H.263(+) @tab X @tab X @tab also known as RealVideo 1.0
b06b45c4 950@item H.264 @tab @tab X
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951@item RealVideo 1.0 @tab X @tab X
952@item RealVideo 2.0 @tab X @tab X
115329f1 953@item MJPEG @tab X @tab X
4c5f7207 954@item lossless MJPEG @tab X @tab X
26d6d032 955@item JPEG-LS @tab X @tab X @tab fourcc: MJLS, lossless and near-lossless is supported
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956@item Apple MJPEG-B @tab @tab X
957@item Sunplus MJPEG @tab @tab X @tab fourcc: SP5X
115329f1 958@item DV @tab X @tab X
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959@item HuffYUV @tab X @tab X
960@item FFmpeg Video 1 @tab X @tab X @tab experimental lossless codec (fourcc: FFV1)
961@item FFmpeg Snow @tab X @tab X @tab experimental wavelet codec (fourcc: SNOW)
701b603d 962@item Asus v1 @tab X @tab X @tab fourcc: ASV1
4d3b1f8d 963@item Asus v2 @tab X @tab X @tab fourcc: ASV2
701b603d 964@item Creative YUV @tab @tab X @tab fourcc: CYUV
d2bfadc0 965@item Sorenson Video 1 @tab X @tab X @tab fourcc: SVQ1
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966@item Sorenson Video 3 @tab @tab X @tab fourcc: SVQ3
967@item On2 VP3 @tab @tab X @tab still experimental
5ce117c3 968@item On2 VP5 @tab @tab X @tab fourcc: VP50
9110a0e3 969@item On2 VP6 @tab @tab X @tab fourcc: VP60,VP61,VP62
150d2772 970@item Theora @tab X @tab X @tab still experimental
cdb2c1ca 971@item Intel Indeo 3 @tab @tab X
9303d49c 972@item FLV @tab X @tab X @tab Sorenson H.263 used in Flash
15419468 973@item Flash Screen Video @tab X @tab X @tab fourcc: FSV1
4d3b1f8d 974@item ATI VCR1 @tab @tab X @tab fourcc: VCR1
7fe4c823 975@item ATI VCR2 @tab @tab X @tab fourcc: VCR2
4d3b1f8d 976@item Cirrus Logic AccuPak @tab @tab X @tab fourcc: CLJR
4c5f7207 977@item 4X Video @tab @tab X @tab Used in certain computer games.
115329f1 978@item Sony Playstation MDEC @tab @tab X
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979@item Id RoQ @tab @tab X @tab Used in Quake III, Jedi Knight 2, other computer games.
980@item Xan/WC3 @tab @tab X @tab Used in Wing Commander III .MVE files.
981@item Interplay Video @tab @tab X @tab Used in Interplay .MVE files.
070ed1bc 982@item Apple Animation @tab @tab X @tab fourcc: 'rle '
42cad81a 983@item Apple Graphics @tab @tab X @tab fourcc: 'smc '
2fdf638b 984@item Apple Video @tab @tab X @tab fourcc: rpza
d08d7142 985@item Apple QuickDraw @tab @tab X @tab fourcc: qdrw
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986@item Cinepak @tab @tab X
987@item Microsoft RLE @tab @tab X
988@item Microsoft Video-1 @tab @tab X
4120a53a 989@item Westwood VQA @tab @tab X
4c5f7207 990@item Id Cinematic Video @tab @tab X @tab Used in Quake II.
1dc1ed99 991@item Planar RGB @tab @tab X @tab fourcc: 8BPS
42cad81a 992@item FLIC video @tab @tab X
9a4117d5 993@item Duck TrueMotion v1 @tab @tab X @tab fourcc: DUCK
dce76c20 994@item Duck TrueMotion v2 @tab @tab X @tab fourcc: TM20
4c5f7207 995@item VMD Video @tab @tab X @tab Used in Sierra VMD files.
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996@item MSZH @tab @tab X @tab Part of LCL
997@item ZLIB @tab X @tab X @tab Part of LCL, encoder experimental
9d53d58e 998@item TechSmith Camtasia @tab @tab X @tab fourcc: TSCC
d0a0bbd2 999@item IBM Ultimotion @tab @tab X @tab fourcc: ULTI
ab711b3c 1000@item Miro VideoXL @tab @tab X @tab fourcc: VIXL
acfd8f0f 1001@item QPEG @tab @tab X @tab fourccs: QPEG, Q1.0, Q1.1
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1002@item LOCO @tab @tab X @tab
1003@item Winnov WNV1 @tab @tab X @tab
589f8220 1004@item Autodesk Animator Studio Codec @tab @tab X @tab fourcc: AASC
115329f1 1005@item Fraps FPS1 @tab @tab X @tab
2b6c1d80 1006@item CamStudio @tab @tab X @tab fourcc: CSCD
4e114829 1007@item American Laser Games Video @tab @tab X @tab Used in games like Mad Dog McCree
f48d6e1b 1008@item ZMBV @tab X @tab X @tab Encoder works only on PAL8
26376701 1009@item AVS Video @tab @tab X @tab Video encoding used by the Creature Shock game.
348efc18 1010@item Smacker Video @tab @tab X @tab Video encoding used in Smacker.
dfca23e3 1011@item RTjpeg @tab @tab X @tab Video encoding used in NuppelVideo files.
fd7b1991 1012@item KMVC @tab @tab X @tab Codec used in Worms games.
eb57c889 1013@item VMware Video @tab @tab X @tab Codec used in videos captured by VMware.
dc56e0de 1014@item Cin Video @tab @tab X @tab Codec used in Delphine Software games.
29f86228 1015@item Tiertex Seq Video @tab @tab X @tab Codec used in DOS CDROM FlashBack game.
33a0dd37 1016@item DXA Video @tab @tab X @tab Codec originally used in Feeble Files game.
52b6bad2 1017@item AVID DNxHD @tab @tab X @tab aka SMPTE VC3
9a0ddd09 1018@item C93 Video @tab @tab X @tab Codec used in Cyberia game.
8845202e 1019@item THP @tab @tab X @tab Used on the Nintendo GameCube.
1e6c6759 1020@item Bethsoft VID @tab @tab X @tab Used in some games from Bethesda Softworks.
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1021@end multitable
1022
4c5f7207 1023@code{X} means that encoding (resp. decoding) is supported.
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1024
1025@section Audio Codecs
1026
1027@multitable @columnfractions .4 .1 .1 .1 .7
1028@item Supported Codec @tab Encoding @tab Decoding @tab Comments
115329f1 1029@item MPEG audio layer 2 @tab IX @tab IX
9181577c 1030@item MPEG audio layer 1/3 @tab IX @tab IX
4c5f7207 1031@tab MP3 encoding is supported through the external library LAME.
37776c3b 1032@item AC3 @tab IX @tab IX
4c5f7207 1033@tab liba52 is used internally for decoding.
34d7008d 1034@item Vorbis @tab X @tab X
74882049 1035@item WMA V1/V2 @tab X @tab X
f6fa7a6c 1036@item AAC @tab X @tab X
4c5f7207 1037@tab Supported through the external library libfaac/libfaad.
d4c3c5a6 1038@item Microsoft ADPCM @tab X @tab X
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1039@item MS IMA ADPCM @tab X @tab X
1040@item QT IMA ADPCM @tab @tab X
1041@item 4X IMA ADPCM @tab @tab X
d4e437df 1042@item G.726 ADPCM @tab X @tab X
b17e9c99 1043@item Duck DK3 IMA ADPCM @tab @tab X
4c5f7207 1044@tab Used in some Sega Saturn console games.
b17e9c99 1045@item Duck DK4 IMA ADPCM @tab @tab X
4c5f7207 1046@tab Used in some Sega Saturn console games.
2fdf638b 1047@item Westwood Studios IMA ADPCM @tab @tab X
4c5f7207 1048@tab Used in Westwood Studios games like Command and Conquer.
7d8379f2 1049@item SMJPEG IMA ADPCM @tab @tab X
4c5f7207 1050@tab Used in certain Loki game ports.
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1051@item CD-ROM XA ADPCM @tab @tab X
1052@item CRI ADX ADPCM @tab X @tab X
4c5f7207 1053@tab Used in Sega Dreamcast games.
7d8379f2 1054@item Electronic Arts ADPCM @tab @tab X
4c5f7207 1055@tab Used in various EA titles.
b3bfb299 1056@item Creative ADPCM @tab @tab X
2433f24f 1057@tab 16 -> 4, 8 -> 4, 8 -> 3, 8 -> 2
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1058@item THP ADPCM @tab @tab X
1059@tab Used on the Nintendo GameCube.
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1060@item RA144 @tab @tab X
1061@tab Real 14400 bit/s codec
1062@item RA288 @tab @tab X
1063@tab Real 28800 bit/s codec
37776c3b 1064@item RADnet @tab X @tab IX
4c5f7207 1065@tab Real low bitrate AC3 codec, liba52 is used for decoding.
2eb5d024 1066@item AMR-NB @tab X @tab X
4c5f7207 1067@tab Supported through an external library.
d663a1fd 1068@item AMR-WB @tab X @tab X
4c5f7207 1069@tab Supported through an external library.
2eb5d024 1070@item DV audio @tab @tab X
4d3b1f8d 1071@item Id RoQ DPCM @tab @tab X
4c5f7207 1072@tab Used in Quake III, Jedi Knight 2, other computer games.
4d3b1f8d 1073@item Interplay MVE DPCM @tab @tab X
4c5f7207 1074@tab Used in various Interplay computer games.
b17e9c99 1075@item Xan DPCM @tab @tab X
4c5f7207 1076@tab Used in Origin's Wing Commander IV AVI files.
d08d7142 1077@item Sierra Online DPCM @tab @tab X
4c5f7207 1078@tab Used in Sierra Online game audio files.
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1079@item Apple MACE 3 @tab @tab X
1080@item Apple MACE 6 @tab @tab X
bfd9a00f 1081@item FLAC lossless audio @tab X @tab X
13dfd2b9 1082@item Shorten lossless audio @tab @tab X
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1083@item Apple lossless audio @tab @tab X
1084@tab QuickTime fourcc 'alac'
33a4d8b1 1085@item FFmpeg Sonic @tab X @tab X
4c5f7207 1086@tab experimental lossy/lossless codec
d9b1c197
RT
1087@item Qdesign QDM2 @tab @tab X
1088@tab there are still some distortions
440e7988
RT
1089@item Real COOK @tab @tab X
1090@tab All versions except 5.1 are supported
e839a994 1091@item DSP Group TrueSpeech @tab @tab X
3dc411c0 1092@item True Audio (TTA) @tab @tab X
348efc18 1093@item Smacker Audio @tab @tab X
730581f3 1094@item WavPack Audio @tab @tab X
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1095@item Cin Audio @tab @tab X
1096@tab Codec used in Delphine Software games.
84ed36da 1097@item Intel Music Coder @tab @tab X
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1098@item Musepack @tab @tab X
1099@tab Only SV7 is supported
01ca9ac3 1100@item DT$ Coherent Audio @tab @tab X
10e26bc7 1101@item ATRAC 3 @tab @tab X
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1102@end multitable
1103
4c5f7207 1104@code{X} means that encoding (resp. decoding) is supported.
9181577c 1105
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1106@code{I} means that an integer-only version is available, too (ensures high
1107performance on systems without hardware floating point support).
9181577c 1108
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1109@chapter Platform Specific information
1110
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1111@section BSD
1112
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1113BSD make will not build FFmpeg, you need to install and use GNU Make
1114(@file{gmake}).
1115
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1116@section Windows
1117
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1118To get help and instructions for using FFmpeg under Windows, check out
1119the FFmpeg Windows Help Forum at
1120@url{http://arrozcru.no-ip.org/ffmpeg/}.
1121
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1122@subsection Native Windows compilation
1123
1124@itemize
1125@item Install the current versions of MSYS and MinGW from
1126@url{http://www.mingw.org/}. You can find detailed installation
1127instructions in the download section and the FAQ.
1128
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1129NOTE: Use at least bash 3.1. Older versions are known to be failing on the
1130configure script.
1131
4c5f7207 1132@item If you want to test the FFplay, also download
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1133the MinGW development library of SDL 1.2.x
1134(@file{SDL-devel-1.2.x-mingw32.tar.gz}) from
4c5f7207 1135@url{http://www.libsdl.org}. Unpack it in a temporary directory, and
50f52fcd 1136unpack the archive @file{i386-mingw32msvc.tar.gz} in the MinGW tool
988a9f9e
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1137directory. Edit the @file{sdl-config} script so that it gives the
1138correct SDL directory when invoked.
50f52fcd 1139
e926e391 1140@item Extract the current version of FFmpeg.
115329f1 1141
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1142@item Start the MSYS shell (file @file{msys.bat}).
1143
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1144@item Change to the FFmpeg directory and follow
1145 the instructions of how to compile FFmpeg (file
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1146@file{INSTALL}). Usually, launching @file{./configure} and @file{make}
1147suffices. If you have problems using SDL, verify that
1148@file{sdl-config} can be launched from the MSYS command line.
1149
4c5f7207 1150@item You can install FFmpeg in @file{Program Files/FFmpeg} by typing
ce10ff8e 1151@file{make install}. Do not forget to copy @file{SDL.dll} to the place
4c5f7207 1152you launch @file{ffplay} from.
50f52fcd 1153
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1154@end itemize
1155
115329f1 1156Notes:
988a9f9e 1157@itemize
50f52fcd 1158
988a9f9e
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1159@item The target @file{make wininstaller} can be used to create a
1160Nullsoft based Windows installer for FFmpeg and FFplay. @file{SDL.dll}
4c5f7207 1161must be copied to the FFmpeg directory in order to build the
988a9f9e
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1162installer.
1163
4c5f7207 1164@item By using @code{./configure --enable-shared} when configuring FFmpeg,
988a9f9e
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1165you can build @file{avcodec.dll} and @file{avformat.dll}. With
1166@code{make install} you install the FFmpeg DLLs and the associated
115329f1 1167headers in @file{Program Files/FFmpeg}.
988a9f9e 1168
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1169@item Visual C++ compatibility: If you used @code{./configure --enable-shared}
1170when configuring FFmpeg, FFmpeg tries to use the Microsoft Visual
988a9f9e 1171C++ @code{lib} tool to build @code{avcodec.lib} and
4c5f7207 1172@code{avformat.lib}. With these libraries you can link your Visual C++
be0efc0c 1173code directly with the FFmpeg DLLs (see below).
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1174
1175@end itemize
b030b284 1176
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1177@subsection Visual C++ compatibility
1178
1179FFmpeg will not compile under Visual C++ -- and it has too many
1180dependencies on the GCC compiler to make a port viable. However,
1181if you want to use the FFmpeg libraries in your own applications,
1182you can still compile those applications using Visual C++. An
1183important restriction to this is that you have to use the
1184dynamically linked versions of the FFmpeg libraries (i.e. the
1185DLLs), and you have to make sure that Visual-C++-compatible
1186import libraries are created during the FFmpeg build process.
1187
1188This description of how to use the FFmpeg libraries with Visual C++ is
1189based on Visual C++ 2005 Express Edition Beta 2. If you have a different
1190version, you might have to modify the procedures slightly.
1191
1192Here are the step-by-step instructions for building the FFmpeg libraries
1193so they can be used with Visual C++:
1194
1195@enumerate
1196
ce10ff8e 1197@item Install Visual C++ (if you have not done so already).
be0efc0c
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1198
1199@item Install MinGW and MSYS as described above.
1200
1201@item Add a call to @file{vcvars32.bat} (which sets up the environment
1202variables for the Visual C++ tools) as the first line of
1203@file{msys.bat}. The standard location for @file{vcvars32.bat} is
1204@file{C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat},
1205and the standard location for @file{msys.bat} is
1206@file{C:\msys\1.0\msys.bat}. If this corresponds to your setup, add the
1207following line as the first line of @file{msys.bat}:
1208
1209@code{call "C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat"}
1210
1211@item Start the MSYS shell (file @file{msys.bat}) and type @code{link.exe}.
1212If you get a help message with the command line options of @code{link.exe},
1213this means your environment variables are set up correctly, the
1214Microsoft linker is on the path and will be used by FFmpeg to
1215create Visual-C++-compatible import libraries.
1216
e926e391 1217@item Extract the current version of FFmpeg and change to the FFmpeg directory.
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1218
1219@item Type the command
51d8321d 1220@code{./configure --enable-shared --disable-static --enable-memalign-hack}
ce10ff8e 1221to configure and, if that did not produce any errors,
51d8321d 1222type @code{make} to build FFmpeg.
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1223
1224@item The subdirectories @file{libavformat}, @file{libavcodec}, and
1225@file{libavutil} should now contain the files @file{avformat.dll},
1226@file{avformat.lib}, @file{avcodec.dll}, @file{avcodec.lib},
1227@file{avutil.dll}, and @file{avutil.lib}, respectively. Copy the three
1228DLLs to your System32 directory (typically @file{C:\Windows\System32}).
1229
1230@end enumerate
1231
1232And here is how to use these libraries with Visual C++:
1233
1234@enumerate
1235
1236@item Create a new console application ("File / New / Project") and then
1237select "Win32 Console Application". On the appropriate page of the
1238Application Wizard, uncheck the "Precompiled headers" option.
1239
1240@item Write the source code for your application, or, for testing, just
1241copy the code from an existing sample application into the source file
1242that Visual C++ has already created for you. (Note that your source
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DB
1243filehas to have a @code{.cpp} extension; otherwise, Visual C++ will not
1244compile the FFmpeg headers correctly because in C mode, it does not
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1245recognize the @code{inline} keyword.) For example, you can copy
1246@file{output_example.c} from the FFmpeg distribution (but you will
1247have to make minor modifications so the code will compile under
1248C++, see below).
1249
1250@item Open the "Project / Properties" dialog box. In the "Configuration"
1251combo box, select "All Configurations" so that the changes you make will
1252affect both debug and release builds. In the tree view on the left hand
1253side, select "C/C++ / General", then edit the "Additional Include
1254Directories" setting to contain the complete paths to the
1255@file{libavformat}, @file{libavcodec}, and @file{libavutil}
1256subdirectories of your FFmpeg directory. Note that the directories have
1257to be separated using semicolons. Now select "Linker / General" from the
1258tree view and edit the "Additional Library Directories" setting to
1259contain the same three directories.
1260
1261@item Still in the "Project / Properties" dialog box, select "Linker / Input"
1262from the tree view, then add the files @file{avformat.lib},
1263@file{avcodec.lib}, and @file{avutil.lib} to the end of the "Additional
1264Dependencies". Note that the names of the libraries have to be separated
1265using spaces.
1266
765c3440 1267@item Now, select "C/C++ / Code Generation" from the tree view. Select
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1268"Debug" in the "Configuration" combo box. Make sure that "Runtime
1269Library" is set to "Multi-threaded Debug DLL". Then, select "Release" in
1270the "Configuration" combo box and make sure that "Runtime Library" is
1271set to "Multi-threaded DLL".
1272
1273@item Click "OK" to close the "Project / Properties" dialog box and build
1274the application. Hopefully, it should compile and run cleanly. If you
1275used @file{output_example.c} as your sample application, you will get a
1276few compiler errors, but they are easy to fix. The first type of error
ce10ff8e 1277occurs because Visual C++ does not allow an @code{int} to be converted to
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MB
1278an @code{enum} without a cast. To solve the problem, insert the required
1279casts (this error occurs once for a @code{CodecID} and once for a
1280@code{CodecType}). The second type of error occurs because C++ requires
1281the return value of @code{malloc} to be cast to the exact type of the
1282pointer it is being assigned to. Visual C++ will complain that, for
1283example, @code{(void *)} is being assigned to @code{(uint8_t *)} without
1284an explicit cast. So insert an explicit cast in these places to silence
1285the compiler. The third type of error occurs because the @code{snprintf}
1286library function is called @code{_snprintf} under Visual C++. So just
1287add an underscore to fix the problem. With these changes,
1288@file{output_example.c} should compile under Visual C++, and the
1289resulting executable should produce valid video files.
1290
1291@end enumerate
1292
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1293@subsection Cross compilation for Windows with Linux
1294
1295You must use the MinGW cross compilation tools available at
1296@url{http://www.mingw.org/}.
1297
4c5f7207 1298Then configure FFmpeg with the following options:
b030b284 1299@example
6b74787b 1300./configure --target-os=mingw32 --cross-prefix=i386-mingw32msvc-
b030b284 1301@end example
019c8838 1302(you can change the cross-prefix according to the prefix chosen for the
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1303MinGW tools).
1304
4c5f7207 1305Then you can easily test FFmpeg with Wine
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1306(@url{http://www.winehq.com/}).
1307
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1308@subsection Compilation under Cygwin
1309
1310Cygwin works very much like Unix.
1311
1312Just install your Cygwin with all the "Base" packages, plus the
1313following "Devel" ones:
1314@example
1315binutils, gcc-core, make, subversion
1316@end example
1317
1318Do not install binutils-20060709-1 (they are buggy on shared builds);
1319use binutils-20050610-1 instead.
1320
1321Then run
1322
1323@example
1324./configure --enable-static --disable-shared
1325@end example
1326
1327to make a static build or
1328
1329@example
1330./configure --enable-shared --disable-static
1331@end example
1332
1333to build shared libraries.
1334
1335If you want to build FFmpeg with additional libraries, download Cygwin
1336"Devel" packages for Ogg and Vorbis from any Cygwin packages repository
1337and/or SDL, xvid, faac, faad2 packages from Cygwin Ports,
1338(@url{http://cygwinports.dotsrc.org/}).
1339
1340@subsection Crosscompilation for Windows under Cygwin
1341
ce10ff8e 1342With Cygwin you can create Windows binaries that do not need the cygwin1.dll.
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DB
1343
1344Just install your Cygwin as explained before, plus these additional
1345"Devel" packages:
1346@example
1347gcc-mingw-core, mingw-runtime, mingw-zlib
1348@end example
1349
1350and add some special flags to your configure invocation.
1351
1352For a static build run
1353@example
6b74787b 1354./configure --target-os=mingw32 --enable-memalign-hack --enable-static --disable-shared --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
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DB
1355@end example
1356
1357and for a build with shared libraries
1358@example
6b74787b 1359./configure --target-os=mingw32 --enable-memalign-hack --enable-shared --disable-static --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
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1360@end example
1361
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1362@section BeOS
1363
1364The configure script should guess the configuration itself.
1365Networking support is currently not finished.
1366errno issues fixed by Andrew Bachmann.
1367
1368Old stuff:
1369
7dd611c9 1370François Revol - revol at free dot fr - April 2002
47d944d2 1371
115329f1 1372The configure script should guess the configuration itself,
ce10ff8e 1373however I still did not test building on the net_server version of BeOS.
47d944d2 1374
4c5f7207 1375FFserver is broken (needs poll() implementation).
47d944d2 1376
4c5f7207 1377There are still issues with errno codes, which are negative in BeOS, and
115329f1 1378that FFmpeg negates when returning. This ends up turning errors into
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1379valid results, then crashes.
1380(To be fixed)
1381
34d7008d 1382@chapter Developers Guide
9181577c
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1383
1384@section API
a0b72f90 1385@itemize @bullet
9181577c 1386@item libavcodec is the library containing the codecs (both encoding and
4c5f7207 1387decoding). Look at @file{libavcodec/apiexample.c} to see how to use it.
9181577c 1388
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1389@item libavformat is the library containing the file format handling (mux and
1390demux code for several formats). Look at @file{ffplay.c} to use it in a
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1391player. See @file{output_example.c} to use it to generate audio or video
1392streams.
1393
9181577c
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1394@end itemize
1395
1396@section Integrating libavcodec or libavformat in your program
1397
1398You can integrate all the source code of the libraries to link them
1399statically to avoid any version problem. All you need is to provide a
1400'config.mak' and a 'config.h' in the parent directory. See the defines
1401generated by ./configure to understand what is needed.
1402
1403You can use libavcodec or libavformat in your commercial program, but
1404@emph{any patch you make must be published}. The best way to proceed is
4c5f7207 1405to send your patches to the FFmpeg mailing list.
9181577c 1406
80d1c272 1407@node Coding Rules
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1408@section Coding Rules
1409
4c5f7207 1410FFmpeg is programmed in the ISO C90 language with a few additional
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1411features from ISO C99, namely:
1412@itemize @bullet
1413@item
1414the @samp{inline} keyword;
1415@item
1416@samp{//} comments;
1417@item
1418designated struct initializers (@samp{struct s x = @{ .i = 17 @};})
1419@item
114afa9c 1420compound literals (@samp{x = (struct s) @{ 17, 23 @};})
cb6e87c1
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1421@end itemize
1422
ce10ff8e
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1423These features are supported by all compilers we care about, so we will not
1424accept patches to remove their use unless they absolutely do not impair
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FH
1425clarity and performance.
1426
4c5f7207 1427All code must compile with GCC 2.95 and GCC 3.3. Currently, FFmpeg also
cb6e87c1
FH
1428compiles with several other compilers, such as the Compaq ccc compiler
1429or Sun Studio 9, and we would like to keep it that way unless it would
ce10ff8e 1430be exceedingly involved. To ensure compatibility, please do not use any
4c5f7207 1431additional C99 features or GCC extensions. Especially watch out for:
cb6e87c1
FH
1432@itemize @bullet
1433@item
1434mixing statements and declarations;
1435@item
1436@samp{long long} (use @samp{int64_t} instead);
1437@item
1438@samp{__attribute__} not protected by @samp{#ifdef __GNUC__} or similar;
1439@item
019c8838 1440GCC statement expressions (@samp{(x = (@{ int y = 4; y; @})}).
cb6e87c1 1441@end itemize
9181577c 1442
53862e0f 1443Indent size is 4.
b86e38a0 1444The presentation is the one specified by 'indent -i4 -kr -nut'.
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1445The TAB character is forbidden outside of Makefiles as is any
1446form of trailing whitespace. Commits containing either will be
1c1b5a40 1447rejected by the Subversion repository.
9181577c 1448
4c5f7207 1449Main priority in FFmpeg is simplicity and small code size (=less
9181577c
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1450bugs).
1451
4c5f7207
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1452Comments: Use the JavaDoc/Doxygen
1453format (see examples below) so that code documentation
1454can be generated automatically. All nontrivial functions should have a comment
ce10ff8e 1455above them explaining what the function does, even if it is just one sentence.
4c5f7207 1456All structures and their member variables should be documented, too.
f4888b83
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1457@example
1458/**
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1459 * @@file mpeg.c
1460 * MPEG codec.
1461 * @@author ...
1462 */
f4888b83
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1463
1464/**
2185824b
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1465 * Summary sentence.
1466 * more text ...
1467 * ...
1468 */
114afa9c 1469typedef struct Foobar@{
2185824b
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1470 int var1; /**< var1 description */
1471 int var2; ///< var2 description
1472 /** var3 description */
1473 int var3;
114afa9c 1474@} Foobar;
f4888b83
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1475
1476/**
2185824b
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1477 * Summary sentence.
1478 * more text ...
1479 * ...
1480 * @@param my_parameter description of my_parameter
1481 * @@return return value description
1482 */
f4888b83
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1483int myfunc(int my_parameter)
1484...
1485@end example
9181577c 1486
115329f1 1487fprintf and printf are forbidden in libavformat and libavcodec,
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1488please use av_log() instead.
1489
1c1b5a40 1490@section Development Policy
7a57b90c
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1491
1492@enumerate
115329f1 1493@item
7a57b90c 1494 You must not commit code which breaks FFmpeg! (Meaning unfinished but
4c5f7207 1495 enabled code which breaks compilation or compiles but does not work or
7a57b90c
MN
1496 breaks the regression tests)
1497 You can commit unfinished stuff (for testing etc), but it must be disabled
1498 (#ifdef etc) by default so it does not interfere with other developers'
1499 work.
115329f1 1500@item
ce10ff8e 1501 You do not have to over-test things. If it works for you, and you think it
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DB
1502 should work for others, then commit. If your code has problems
1503 (portability, triggers compiler bugs, unusual environment etc) they will be
7a57b90c 1504 reported and eventually fixed.
115329f1 1505@item
7a57b90c 1506 Do not commit unrelated changes together, split them into self-contained
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DB
1507 pieces. Also do not forget that if part B depends on part A, but A does not
1508 depend on B, then A can and should be committed first and separate from B.
1509 Keeping changes well split into self-contained parts makes reviewing and
1510 understanding them on the commit log mailing list easier. This also helps
1511 in case of debugging later on.
1512 Also if you have doubts about splitting or not splitting, do not hesitate to
442d1598 1513 ask/discuss it on the developer mailing list.
7a57b90c
MN
1514@item
1515 Do not change behavior of the program (renaming options etc) without
019c8838 1516 first discussing it on the ffmpeg-devel mailing list. Do not remove
7a57b90c 1517 functionality from the code. Just improve!
115329f1 1518
4c5f7207 1519 Note: Redundant code can be removed.
7a57b90c
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1520@item
1521 Do not commit changes to the build system (Makefiles, configure script)
019c8838 1522 which change behavior, defaults etc, without asking first. The same
7a57b90c
MN
1523 applies to compiler warning fixes, trivial looking fixes and to code
1524 maintained by other developers. We usually have a reason for doing things
019c8838 1525 the way we do. Send your changes as patches to the ffmpeg-devel mailing
7a57b90c
MN
1526 list, and if the code maintainers say OK, you may commit. This does not
1527 apply to files you wrote and/or maintain.
1528@item
1529 We refuse source indentation and other cosmetic changes if they are mixed
1530 with functional changes, such commits will be rejected and removed. Every
1531 developer has his own indentation style, you should not change it. Of course
1532 if you (re)write something, you can use your own style, even though we would
4c5f7207 1533 prefer if the indentation throughout FFmpeg was consistent (Many projects
ce10ff8e 1534 force a given indentation style - we do not.). If you really need to make
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1535 indentation changes (try to avoid this), separate them strictly from real
1536 changes.
1537
114afa9c 1538 NOTE: If you had to put if()@{ .. @} over a large (> 5 lines) chunk of code,
ce10ff8e 1539 then either do NOT change the indentation of the inner part within (do not
019c8838 1540 move it to the right)! or do so in a separate commit
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1541@item
1542 Always fill out the commit log message. Describe in a few lines what you
1543 changed and why. You can refer to mailing list postings if you fix a
1544 particular bug. Comments such as "fixed!" or "Changed it." are unacceptable.
1545@item
1546 If you apply a patch by someone else, include the name and email address in
1c1b5a40 1547 the log message. Since the ffmpeg-cvslog mailing list is publicly
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1548 archived you should add some SPAM protection to the email address. Send an
1549 answer to ffmpeg-devel (or wherever you got the patch from) saying that
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1550 you applied the patch.
1551@item
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1552 When applying patches that have been discussed (at length) on the mailing
1553 list, reference the thread in the log message.
1554@item
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1555 Do NOT commit to code actively maintained by others without permission.
1556 Send a patch to ffmpeg-devel instead. If noone answers within a reasonable
1557 timeframe (12h for build failures and security fixes, 3 days small changes,
ce10ff8e 1558 1 week for big patches) then commit your patch if you think it is OK.
5ab0f204 1559 Also note, the maintainer can simply ask for more time to review!
7a57b90c 1560@item
1c1b5a40 1561 Subscribe to the ffmpeg-cvslog mailing list. The diffs of all commits
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1562 are sent there and reviewed by all the other developers. Bugs and possible
1563 improvements or general questions regarding commits are discussed there. We
1564 expect you to react if problems with your code are uncovered.
1565@item
1566 Update the documentation if you change behavior or add features. If you are
019c8838 1567 unsure how best to do this, send a patch to ffmpeg-devel, the documentation
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1568 maintainer(s) will review and commit your stuff.
1569@item
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1570 Try to keep important discussions and requests (also) on the public
1571 developer mailing list, so that all developers can benefit from them.
1572@item
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1573 Never write to unallocated memory, never write over the end of arrays,
1574 always check values read from some untrusted source before using them
1575 as array index or other risky things.
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1576@item
1577 Remember to check if you need to bump versions for the specific libav
f0efbde7 1578 parts (libavutil, libavcodec, libavformat) you are changing. You need
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1579 to change the version integer and the version string.
1580 Incrementing the first component means no backward compatibility to
a940b428 1581 previous versions (e.g. removal of a function from the public API).
76bec1d8 1582 Incrementing the second component means backward compatible change
a940b428 1583 (e.g. addition of a function to the public API).
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1584 Incrementing the third component means a noteworthy binary compatible
1585 change (e.g. encoder bug fix that matters for the decoder).
ebd32fd7 1586@item
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1587 If you add a new codec, remember to update the changelog, add it to
1588 the supported codecs table in the documentation and bump the second
1589 component of the @file{libavcodec} version number appropriately. If
1590 it has a fourcc, add it to @file{libavformat/avienc.c}, even if it
1591 is only a decoder.
65d0bea8 1592@item
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1593 Do not change code to hide warnings without ensuring that the underlying
1594 logic is correct and thus the warning was inappropriate.
114afa9c 1595@end enumerate
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1596
1597We think our rules are not too hard. If you have comments, contact us.
1598
1599Note, these rules are mostly borrowed from the MPlayer project.
1600
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1601@section Submitting patches
1602
ce10ff8e 1603First, (@pxref{Coding Rules}) above if you did not yet.
80d1c272 1604
6a6810b1 1605When you submit your patch, try to send a unified diff (diff '-up'
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1606option). I cannot read other diffs :-)
1607
6e5c1877 1608Also please do not submit patches which contain several unrelated changes.
115329f1 1609Split them into individual self-contained patches; this makes reviewing
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1610them much easier.
1611
9181577c 1612Run the regression tests before submitting a patch so that you can
6bf40f39 1613verify that there are no big problems.
9181577c 1614
9181577c 1615Patches should be posted as base64 encoded attachments (or any other
ce10ff8e 1616encoding which ensures that the patch will not be trashed during
115329f1 1617transmission) to the ffmpeg-devel mailing list, see
2b165e29 1618@url{http://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel}
9181577c 1619
54fcf429 1620It also helps quite a bit if you tell us what the patch does (for example
4c5f7207 1621'replaces lrint by lrintf'), and why (for example '*BSD isn't C99 compliant
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1622and has no lrint()')
1623
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1624Also please if you send several patches, send each patch as separate mail,
1625do not attach several unrelated patches to the same mail.
a15bcf70 1626
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1627@section patch submission checklist
1628
1629@enumerate
1630@item
1631 Do the regression tests pass with the patch applied?
1632@item
1633 Is the patch a unified diff?
1634@item
4a7a0908 1635 Is the patch against latest FFmpeg SVN?
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1636@item
1637 Are you subscribed to ffmpeg-dev?
1638 (the list is subscribers only due to spam)
1639@item
1640 Have you checked that the changes are minimal, so that the same cannot be
442d1598 1641 achieved with a smaller patch and/or simpler final code?
dd597cd7 1642@item
4a7a0908 1643 If the change is to speed critical code, did you benchmark it?
dd597cd7 1644@item
442d1598 1645 Have you checked that the patch does not introduce buffer overflows or
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1646 other security issues?
1647@item
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1648 Is the patch created from the root of the source tree, so it can be
1649 applied with @code{patch -p0}?
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1650@item
1651 Does the patch not mix functional and cosmetic changes?
1652@item
1653 Is the patch attached to the email you send?
1654@item
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1655 Is the mime type of the patch correct? It should be text/x-diff or
1656 text/x-patch or at least text/plain and not application/octet-stream.
dd597cd7 1657@item
4a7a0908 1658 If the patch fixes a bug, did you provide a verbose analysis of the bug?
dd597cd7 1659@item
4a7a0908 1660 If the patch fixes a bug, did you provide enough information, including
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1661 a sample, so the bug can be reproduced and the fix can be verified?
1662@item
1663 Did you provide a verbose summary about what the patch does change?
1664@item
1665 Did you provide a verbose explanation why it changes things like it does?
1666@item
442d1598 1667 Did you provide a verbose summary of the user visible advantages and
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1668 disadvantages if the patch is applied?
1669@item
1670 Did you provide an example so we can verify the new feature added by the
1671 patch easily?
1672@item
1673 If you did any benchmarks, did you provide them in the mail?
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1674@item
1675 If you added a new file, did you insert a license header? It should be
1676 taken from FFmpeg, not randomly copy and pasted from somewhere else.
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1677@end enumerate
1678
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1679@section Patch review process
1680
1681All patches posted to ffmpeg-devel will be reviewed, unless they contain a
1682clear note that the patch is not for SVN.
1683Reviews and comments will be posted as replies to the patch on the
ce10ff8e 1684mailing list. The patch submitter then has to take care of every comment,
442d1598 1685that can be by resubmitting a changed patch or by discussion. Resubmitted
ce10ff8e 1686patches will themselves be reviewed like any other patch. If at some point
f5f11d71 1687a patch passes review with no comments then it is approved, that can for
ce10ff8e 1688simple and small patches happen immediately while large patches will generally
f5f11d71 1689have to be changed and reviewed many times before they are approved.
ce10ff8e 1690After a patch is approved it will be committed to the repository.
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1691
1692We will review all submitted patches, but sometimes we are quite busy so
1693especially for large patches this can take several weeks.
1694
1695When resubmitting patches, please do not make any significant changes
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1696not related to the comments received during review. Such patches will
1697be rejected. Instead, submit significant changes or new features as
1698separate patches.
cf7f2b16 1699
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1700@section Regression tests
1701
1c1b5a40 1702Before submitting a patch (or committing to the repository), you should at least
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1703test that you did not break anything.
1704
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1705The regression tests build a synthetic video stream and a synthetic
1706audio stream. These are then encoded and decoded with all codecs or
9181577c 1707formats. The CRC (or MD5) of each generated file is recorded in a
4c5f7207 1708result file. A 'diff' is launched to compare the reference results and
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1709the result file.
1710
4c5f7207 1711The regression tests then go on to test the FFserver code with a
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1712limited set of streams. It is important that this step runs correctly
1713as well.
1714
36d9b4e8 1715Run 'make test' to test all the codecs and formats.
9181577c 1716
4c5f7207 1717Run 'make fulltest' to test all the codecs, formats and FFserver.
9181577c 1718
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1719[Of course, some patches may change the results of the regression tests. In
1720this case, the reference results of the regression tests shall be modified
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1721accordingly].
1722
1723@bye