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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 use a video4linux compatible video source and any Open Sound
30System audio source:
31
9181577c 32@example
115329f1 33ffmpeg /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
6bf40f39 42@section Video and Audio file format conversion
9181577c 43
4c5f7207 44* FFmpeg can use any supported file format and protocol as input:
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45
46Examples:
47
4c5f7207 48* You can use YUV files as input:
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49
50@example
115329f1 51ffmpeg -i /tmp/test%d.Y /tmp/out.mpg
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52@end example
53
115329f1 54It will use the files:
9181577c 55@example
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56/tmp/test0.Y, /tmp/test0.U, /tmp/test0.V,
57/tmp/test1.Y, /tmp/test1.U, /tmp/test1.V, etc...
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58@end example
59
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60The Y files use twice the resolution of the U and V files. They are
61raw files, without header. They can be generated by all decent video
62decoders. You must specify the size of the image with the @option{-s} option
4c5f7207 63if FFmpeg cannot guess it.
9181577c 64
4c5f7207 65* You can input from a raw YUV420P file:
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66
67@example
e99c4e10 68ffmpeg -i /tmp/test.yuv /tmp/out.avi
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69@end example
70
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71test.yuv is a file containing raw YUV planar data. Each frame is composed
72of the Y plane followed by the U and V planes at half vertical and
e99c4e10 73horizontal resolution.
9181577c 74
4c5f7207 75* You can output to a raw YUV420P file:
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76
77@example
f926cbe7 78ffmpeg -i mydivx.avi hugefile.yuv
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79@end example
80
81* You can set several input files and output files:
82
83@example
e99c4e10 84ffmpeg -i /tmp/a.wav -s 640x480 -i /tmp/a.yuv /tmp/a.mpg
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85@end example
86
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87Converts the audio file a.wav and the raw YUV video file a.yuv
88to MPEG file a.mpg.
9181577c 89
6bf40f39 90* You can also do audio and video conversions at the same time:
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91
92@example
e99c4e10 93ffmpeg -i /tmp/a.wav -ar 22050 /tmp/a.mp2
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94@end example
95
4c5f7207 96Converts a.wav to MPEG audio at 22050Hz sample rate.
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97
98* You can encode to several formats at the same time and define a
e99c4e10 99mapping from input stream to output streams:
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100
101@example
e99c4e10 102ffmpeg -i /tmp/a.wav -ab 64 /tmp/a.mp2 -ab 128 /tmp/b.mp2 -map 0:0 -map 0:0
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103@end example
104
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105Converts a.wav to a.mp2 at 64 kbits and to b.mp2 at 128 kbits. '-map
106file:index' specifies which input stream is used for each output
e99c4e10 107stream, in the order of the definition of output streams.
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108
109* You can transcode decrypted VOBs
110
111@example
e99c4e10 112ffmpeg -i snatch_1.vob -f avi -vcodec mpeg4 -b 800 -g 300 -bf 2 -acodec mp3 -ab 128 snatch.avi
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113@end example
114
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115This is a typical DVD ripping example; the input is a VOB file, the
116output an AVI file with MPEG-4 video and MP3 audio. Note that in this
117command we use B-frames so the MPEG-4 stream is DivX5 compatible, and
118GOP size is 300 which means one intra frame every 10 seconds for 29.97fps
119input video. Furthermore, the audio stream is MP3-encoded so you need
120to enable LAME support by passing @code{--enable-mp3lame} to configure.
121The mapping is particularly useful for DVD transcoding
e99c4e10 122to get the desired audio language.
9181577c 123
4c5f7207 124NOTE: To see the supported input formats, use @code{ffmpeg -formats}.
e99c4e10 125@c man end
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126
127@chapter Invocation
128
129@section Syntax
130
e99c4e10 131The generic syntax is:
9181577c 132
115329f1 133@example
e99c4e10 134@c man begin SYNOPSIS
28f88dc8 135ffmpeg [[infile options][@option{-i} @var{infile}]]... @{[outfile options] @var{outfile}@}...
e99c4e10 136@c man end
9181577c 137@end example
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138@c man begin DESCRIPTION
139If no input file is given, audio/video grabbing is done.
9181577c 140
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141As a general rule, options are applied to the next specified
142file. For example, if you give the @option{-b 64} option, it sets the video
4c5f7207 143bitrate of the next file. The format option may be needed for raw input
e99c4e10 144files.
9181577c 145
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146By default, FFmpeg tries to convert as losslessly as possible: It
147uses the same audio and video parameters for the outputs as the one
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148specified for the inputs.
149@c man end
9181577c 150
e99c4e10 151@c man begin OPTIONS
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152@section Main options
153
e99c4e10 154@table @option
9181577c 155@item -L
4c5f7207 156Show license.
18bff752 157
9181577c 158@item -h
4c5f7207 159Show help.
18bff752 160
e99c4e10 161@item -formats
4c5f7207 162Show available formats, codecs, protocols, ...
18bff752 163
115329f1 164@item -f fmt
4c5f7207 165Force format.
18bff752 166
115329f1 167@item -i filename
4c5f7207 168input filename
9181577c 169
115329f1 170@item -y
4c5f7207 171Overwrite output files.
9181577c 172
115329f1 173@item -t duration
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174Set the recording time in seconds.
175@code{hh:mm:ss[.xxx]} syntax is also supported.
9181577c 176
e83a84ac 177@item -ss position
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178Seek to given time position in seconds.
179@code{hh:mm:ss[.xxx]} syntax is also supported.
e83a84ac 180
115329f1 181@item -title string
4c5f7207 182Set the title.
9181577c 183
115329f1 184@item -author string
4c5f7207 185Set the author.
9181577c 186
115329f1 187@item -copyright string
4c5f7207 188Set the copyright.
9181577c 189
115329f1 190@item -comment string
4c5f7207 191Set the comment.
9181577c 192
99db6420 193@item -target type
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194Specify target file type ("vcd", "svcd", "dvd", "dv", "pal-vcd",
195"ntsc-svcd", ... ). All the format options (bitrate, codecs,
196buffer sizes) are then set automatically. You can just type:
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197
198@example
199ffmpeg -i myfile.avi -target vcd /tmp/vcd.mpg
200@end example
201
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202Nevertheless you can specify additional options as long as you know
203they do not conflict with the standard, as in:
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204
205@example
206ffmpeg -i myfile.avi -target vcd -bf 2 /tmp/vcd.mpg
207@end example
208
99db6420 209@item -hq
4c5f7207 210Activate high quality settings.
18bff752 211
401fbdde 212@item -itsoffset offset
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213Set the input time offset in seconds.
214@code{[-]hh:mm:ss[.xxx]} syntax is also supported.
215This option affects all the input files that follow it.
216The offset is added to the timestamps of the input files.
217Specifying a positive offset means that the corresponding
218streams are delayed by 'offset' seconds.
401fbdde 219
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220@end table
221
222@section Video Options
223
e99c4e10 224@table @option
9181577c 225@item -b bitrate
4c5f7207 226Set the video bitrate in kbit/s (default = 200 kb/s).
115329f1 227@item -r fps
4c5f7207 228Set frame rate (default = 25).
115329f1 229@item -s size
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230Set frame size. The format is @samp{wxh} (default = 160x128).
231The following abbreviations are recognized:
5ee03c86 232@table @samp
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233@item sqcif
234128x96
235@item qcif
236176x144
237@item cif
238352x288
239@item 4cif
240704x576
241@end table
242
243@item -aspect aspect
4c5f7207 244Set aspect ratio (4:3, 16:9 or 1.3333, 1.7777).
18bff752 245@item -croptop size
4c5f7207 246Set top crop band size (in pixels).
18bff752 247@item -cropbottom size
4c5f7207 248Set bottom crop band size (in pixels).
18bff752 249@item -cropleft size
4c5f7207 250Set left crop band size (in pixels).
18bff752 251@item -cropright size
4c5f7207 252Set right crop band size (in pixels).
1ff93ffc 253@item -padtop size
4c5f7207 254Set top pad band size (in pixels).
1ff93ffc 255@item -padbottom size
4c5f7207 256Set bottom pad band size (in pixels).
1ff93ffc 257@item -padleft size
4c5f7207 258Set left pad band size (in pixels).
1ff93ffc 259@item -padright size
4c5f7207 260Set right pad band size (in pixels).
5b79a73e 261@item -padcolor (hex color)
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262Set color of padded bands. The value for padcolor is expressed
263as a six digit hexadecimal number where the first two digits
264represent red, the middle two digits green and last two digits
265blue (default = 000000 (black)).
9181577c 266@item -vn
4c5f7207 267Disable video recording.
115329f1 268@item -bt tolerance
4c5f7207 269Set video bitrate tolerance (in kbit/s).
18bff752 270@item -maxrate bitrate
4c5f7207 271Set max video bitrate tolerance (in kbit/s).
18bff752 272@item -minrate bitrate
4c5f7207 273Set min video bitrate tolerance (in kbit/s).
18bff752 274@item -bufsize size
4c5f7207 275Set rate control buffer size (in kbit).
115329f1 276@item -vcodec codec
4c5f7207 277Force video codec to @var{codec}. Use the @code{copy} special value to
5ee03c86 278tell that the raw codec data must be copied as is.
18bff752 279@item -sameq
4c5f7207 280Use same video quality as source (implies VBR).
9181577c 281
115329f1 282@item -pass n
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283Select the pass number (1 or 2). It is useful to do two pass
284encoding. The statistics of the video are recorded in the first
285pass and the video is generated at the exact requested bitrate
286in the second pass.
9181577c 287
115329f1 288@item -passlogfile file
4c5f7207 289Set two pass logfile name to @var{file}.
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290
291@end table
292
18bff752 293@section Advanced Video Options
9181577c 294
e99c4e10 295@table @option
115329f1 296@item -g gop_size
4c5f7207 297Set the group of pictures size.
115329f1 298@item -intra
4c5f7207 299Use only intra frames.
115329f1 300@item -qscale q
4c5f7207 301Use fixed video quantiser scale (VBR).
115329f1 302@item -qmin q
4c5f7207 303minimum video quantiser scale (VBR)
115329f1 304@item -qmax q
4c5f7207 305maximum video quantiser scale (VBR)
115329f1 306@item -qdiff q
4c5f7207 307maximum difference between the quantiser scales (VBR)
115329f1 308@item -qblur blur
9181577c 309video quantiser scale blur (VBR)
115329f1 310@item -qcomp compression
9181577c 311video quantiser scale compression (VBR)
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312
313@item -rc_init_cplx complexity
4c5f7207 314initial complexity for single pass encoding
18bff752 315@item -b_qfactor factor
4c5f7207 316qp factor between P- and B-frames
18bff752 317@item -i_qfactor factor
4c5f7207 318qp factor between P- and I-frames
18bff752 319@item -b_qoffset offset
4c5f7207 320qp offset between P- and B-frames
18bff752 321@item -i_qoffset offset
4c5f7207 322qp offset between P- and I-frames
18bff752 323@item -rc_eq equation
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324Set rate control equation (@pxref{FFmpeg formula
325evaluator}) (default = @code{tex^qComp}).
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326@item -rc_override override
327rate control override for specific intervals
18bff752 328@item -me method
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329Set motion estimation method to @var{method}.
330Available methods are (from lowest to best quality):
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331@table @samp
332@item zero
5ee03c86 333Try just the (0, 0) vector.
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334@item phods
335@item log
336@item x1
337@item epzs
338(default method)
339@item full
340exhaustive search (slow and marginally better than epzs)
341@end table
342
343@item -dct_algo algo
4c5f7207 344Set DCT algorithm to @var{algo}. Available values are:
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345@table @samp
346@item 0
347FF_DCT_AUTO (default)
348@item 1
349FF_DCT_FASTINT
350@item 2
351FF_DCT_INT
352@item 3
353FF_DCT_MMX
354@item 4
355FF_DCT_MLIB
356@item 5
357FF_DCT_ALTIVEC
358@end table
359
360@item -idct_algo algo
4c5f7207 361Set IDCT algorithm to @var{algo}. Available values are:
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362@table @samp
363@item 0
364FF_IDCT_AUTO (default)
365@item 1
115329f1 366FF_IDCT_INT
18bff752 367@item 2
115329f1 368FF_IDCT_SIMPLE
18bff752 369@item 3
115329f1 370FF_IDCT_SIMPLEMMX
18bff752 371@item 4
115329f1 372FF_IDCT_LIBMPEG2MMX
18bff752 373@item 5
115329f1 374FF_IDCT_PS2
18bff752 375@item 6
115329f1 376FF_IDCT_MLIB
18bff752 377@item 7
115329f1 378FF_IDCT_ARM
18bff752 379@item 8
115329f1 380FF_IDCT_ALTIVEC
18bff752 381@item 9
115329f1 382FF_IDCT_SH4
18bff752 383@item 10
115329f1 384FF_IDCT_SIMPLEARM
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385@end table
386
387@item -er n
4c5f7207 388Set error resilience to @var{n}.
18bff752 389@table @samp
115329f1 390@item 1
1471c6c2 391FF_ER_CAREFUL (default)
18bff752 392@item 2
5ee03c86 393FF_ER_COMPLIANT
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394@item 3
395FF_ER_AGGRESSIVE
396@item 4
397FF_ER_VERY_AGGRESSIVE
398@end table
399
5ee03c86 400@item -ec bit_mask
4c5f7207 401Set error concealment to @var{bit_mask}. @var{bit_mask} is a bit mask of
5ee03c86 402the following values:
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403@table @samp
404@item 1
4c5f7207 405FF_EC_GUESS_MVS (default = enabled)
18bff752 406@item 2
4c5f7207 407FF_EC_DEBLOCK (default = enabled)
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408@end table
409
410@item -bf frames
4c5f7207 411Use 'frames' B-frames (supported for MPEG-1, MPEG-2 and MPEG-4).
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412@item -mbd mode
413macroblock decision
414@table @samp
415@item 0
4c5f7207 416FF_MB_DECISION_SIMPLE: Use mb_cmp (cannot change it yet in FFmpeg).
18bff752 417@item 1
4c5f7207 418FF_MB_DECISION_BITS: Choose the one which needs the fewest bits.
18bff752 419@item 2
019c8838 420FF_MB_DECISION_RD: rate distortion
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421@end table
422
423@item -4mv
4c5f7207 424Use four motion vector by macroblock (MPEG-4 only).
18bff752 425@item -part
4c5f7207 426Use data partitioning (MPEG-4 only).
18bff752 427@item -bug param
4c5f7207 428Work around encoder bugs that are not auto-detected.
18bff752 429@item -strict strictness
4c5f7207 430How strictly to follow the standards.
5ee03c86 431@item -aic
4c5f7207 432Enable Advanced intra coding (h263+).
5ee03c86 433@item -umv
4c5f7207 434Enable Unlimited Motion Vector (h263+)
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435
436@item -deinterlace
4c5f7207 437Deinterlace pictures.
99db6420 438@item -interlace
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439Force interlacing support in encoder (MPEG-2 and MPEG-4 only).
440Use this option if your input file is interlaced and you want
441to keep the interlaced format for minimum losses.
442The alternative is to deinterlace the input stream with
443@option{-deinterlace}, but deinterlacing introduces losses.
18bff752 444@item -psnr
4c5f7207 445Calculate PSNR of compressed frames.
18bff752 446@item -vstats
4c5f7207 447Dump video coding statistics to @file{vstats_HHMMSS.log}.
18bff752 448@item -vhook module
4c5f7207 449Insert video processing @var{module}. @var{module} contains the module
18bff752 450name and its parameters separated by spaces.
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451@end table
452
453@section Audio Options
454
455@table @option
115329f1 456@item -ar freq
4c5f7207 457Set the audio sampling frequency (default = 44100 Hz).
115329f1 458@item -ab bitrate
4c5f7207 459Set the audio bitrate in kbit/s (default = 64).
18bff752 460@item -ac channels
4c5f7207 461Set the number of audio channels (default = 1).
5ee03c86 462@item -an
4c5f7207 463Disable audio recording.
5ee03c86 464@item -acodec codec
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465Force audio codec to @var{codec}. Use the @code{copy} special value to
466specify that the raw codec data must be copied as is.
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467@end table
468
469@section Audio/Video grab options
470
471@table @option
472@item -vd device
4c5f7207 473sEt video grab device (e.g. @file{/dev/video0}).
18bff752 474@item -vc channel
4c5f7207 475Set video grab channel (DV1394 only).
18bff752 476@item -tvstd standard
4c5f7207 477Set television standard (NTSC, PAL (SECAM)).
18bff752 478@item -dv1394
4c5f7207 479Set DV1394 grab.
18bff752 480@item -ad device
4c5f7207 481Set audio device (e.g. @file{/dev/dsp}).
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482@end table
483
484@section Advanced options
485
486@table @option
115329f1 487@item -map file:stream
4c5f7207 488Set input stream mapping.
18bff752 489@item -debug
4c5f7207 490Print specific debug info.
115329f1 491@item -benchmark
4c5f7207 492Add timings for benchmarking.
115329f1 493@item -hex
4c5f7207 494Dump each input packet.
18bff752 495@item -bitexact
4c5f7207 496Only use bit exact algorithms (for codec testing).
18bff752 497@item -ps size
4c5f7207 498Set packet size in bits.
5ee03c86 499@item -re
4c5f7207 500Read input at native frame rate. Mainly used to simulate a grab device.
5ee03c86 501@item -loop
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502Loop over the input stream. Currently it works only for image
503streams. This option is used for automatic FFserver testing.
8108551a 504@item -loop_output number_of_times
019c8838 505Repeatedly loop output for formats that support looping such as animated GIF
4c5f7207 506(0 will loop the output infinitely).
c52e13f1 507@item -vsync parameter
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508Video sync method. Video will be stretched/squeezed to match the timestamps,
509it is done by duplicating and dropping frames. With -map you can select from
510which stream the timestamps should be taken. You can leave either video or
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511audio unchanged and sync the remaining stream(s) to the unchanged one.
512@item -async samples_per_second
29c9183c 513Audio sync method. "Stretches/squeezes" the audio stream to match the timestamps,
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514the parameter is the maximum samples per second by which the audio is changed.
515-async 1 is a special case where only the start of the audio stream is corrected
516without any later correction.
9181577c 517@end table
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518
519@node FFmpeg formula evaluator
520@section FFmpeg formula evaluator
521
522When evaluating a rate control string, FFmpeg uses an internal formula
115329f1 523evaluator.
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524
525The following binary operators are available: @code{+}, @code{-},
526@code{*}, @code{/}, @code{^}.
527
528The following unary operators are available: @code{+}, @code{-},
529@code{(...)}.
530
531The following functions are available:
532@table @var
533@item sinh(x)
534@item cosh(x)
535@item tanh(x)
536@item sin(x)
537@item cos(x)
538@item tan(x)
539@item exp(x)
540@item log(x)
541@item squish(x)
542@item gauss(x)
543@item abs(x)
544@item max(x, y)
545@item min(x, y)
546@item gt(x, y)
547@item lt(x, y)
548@item eq(x, y)
549@item bits2qp(bits)
550@item qp2bits(qp)
551@end table
552
553The following constants are available:
554@table @var
555@item PI
556@item E
557@item iTex
558@item pTex
559@item tex
560@item mv
561@item fCode
562@item iCount
563@item mcVar
564@item var
565@item isI
566@item isP
567@item isB
568@item avgQP
569@item qComp
570@item avgIITex
571@item avgPITex
572@item avgPPTex
573@item avgBPTex
574@item avgTex
575@end table
576
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577@c man end
578
579@ignore
580
581@setfilename ffmpeg
582@settitle FFmpeg video converter
583
584@c man begin SEEALSO
019c8838 585ffserver(1), ffplay(1) and the HTML documentation of @file{ffmpeg}.
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586@c man end
587
588@c man begin AUTHOR
589Fabrice Bellard
590@c man end
591
592@end ignore
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593
594@section Protocols
595
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596The filename can be @file{-} to read from standard input or to write
597to standard output.
9181577c 598
4c5f7207 599FFmpeg also handles many protocols specified with an URL syntax.
9181577c 600
4c5f7207 601Use 'ffmpeg -formats' to see a list of the supported protocols.
9181577c 602
e99c4e10 603The protocol @code{http:} is currently used only to communicate with
4c5f7207 604FFserver (see the FFserver documentation). When FFmpeg will be a
e99c4e10 605video player it will also be used for streaming :-)
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606
607@chapter Tips
608
609@itemize
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610@item For streaming at very low bitrate application, use a low frame rate
611and a small GOP size. This is especially true for RealVideo where
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612the Linux player does not seem to be very fast, so it can miss
613frames. An example is:
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614
615@example
e99c4e10 616ffmpeg -g 3 -r 3 -t 10 -b 50 -s qcif -f rv10 /tmp/b.rm
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617@end example
618
619@item The parameter 'q' which is displayed while encoding is the current
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620quantizer. The value 1 indicates that a very good quality could
621be achieved. The value 31 indicates the worst quality. If q=31 appears
e99c4e10 622too often, it means that the encoder cannot compress enough to meet
4c5f7207 623your bitrate. You must either increase the bitrate, decrease the
e99c4e10 624frame rate or decrease the frame size.
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625
626@item If your computer is not fast enough, you can speed up the
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627compression at the expense of the compression ratio. You can use
628'-me zero' to speed up motion estimation, and '-intra' to disable
4c5f7207 629motion estimation completely (you have only I-frames, which means it
e99c4e10 630is about as good as JPEG compression).
9181577c 631
4c5f7207 632@item To have very low audio bitrates, reduce the sampling frequency
019c8838 633(down to 22050 kHz for MPEG audio, 22050 or 11025 for AC3).
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634
635@item To have a constant quality (but a variable bitrate), use the option
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636'-qscale n' when 'n' is between 1 (excellent quality) and 31 (worst
637quality).
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638
639@item When converting video files, you can use the '-sameq' option which
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640uses the same quality factor in the encoder as in the decoder.
641It allows almost lossless encoding.
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642
643@end itemize
644
645@chapter Supported File Formats and Codecs
646
647You can use the @code{-formats} option to have an exhaustive list.
648
649@section File Formats
650
6bf40f39 651FFmpeg supports the following file formats through the @code{libavformat}
0699d2fe 652library:
9181577c 653
3fc9e78f 654@multitable @columnfractions .4 .1 .1 .4
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655@item Supported File Format @tab Encoding @tab Decoding @tab Comments
656@item MPEG audio @tab X @tab X
4c5f7207 657@item MPEG-1 systems @tab X @tab X
9181577c 658@tab muxed audio and video
4c5f7207 659@item MPEG-2 PS @tab X @tab X
9181577c 660@tab also known as @code{VOB} file
4c5f7207 661@item MPEG-2 TS @tab @tab X
9181577c 662@tab also known as DVB Transport Stream
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663@item ASF@tab X @tab X
664@item AVI@tab X @tab X
665@item WAV@tab X @tab X
9181577c 666@item Macromedia Flash@tab X @tab X
4c5f7207 667@tab Only embedded audio is decoded.
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668@item FLV @tab X @tab X
669@tab Macromedia Flash video files
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670@item Real Audio and Video @tab X @tab X
671@item Raw AC3 @tab X @tab X
672@item Raw MJPEG @tab X @tab X
673@item Raw MPEG video @tab X @tab X
674@item Raw PCM8/16 bits, mulaw/Alaw@tab X @tab X
675@item Raw CRI ADX audio @tab X @tab X
676@item Raw Shorten audio @tab @tab X
677@item SUN AU format @tab X @tab X
7fe4c823 678@item NUT @tab X @tab X @tab NUT Open Container Format
115329f1 679@item QuickTime @tab X @tab X
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680@item MPEG-4 @tab X @tab X
681@tab MPEG-4 is a variant of QuickTime.
115329f1 682@item Raw MPEG4 video @tab X @tab X
4fa1c4fa 683@item DV @tab X @tab X
701b603d 684@item 4xm @tab @tab X
4c5f7207 685@tab 4X Technologies format, used in some games.
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686@item Playstation STR @tab @tab X
687@item Id RoQ @tab @tab X
4c5f7207 688@tab Used in Quake III, Jedi Knight 2, other computer games.
4d3b1f8d 689@item Interplay MVE @tab @tab X
4c5f7207 690@tab Format used in various Interplay computer games.
b17e9c99 691@item WC3 Movie @tab @tab X
4c5f7207 692@tab Multimedia format used in Origin's Wing Commander III computer game.
2fdf638b 693@item Sega FILM/CPK @tab @tab X
4c5f7207 694@tab Used in many Sega Saturn console games.
2fdf638b 695@item Westwood Studios VQA/AUD @tab @tab X
4c5f7207 696@tab Multimedia formats used in Westwood Studios games.
4120a53a 697@item Id Cinematic (.cin) @tab @tab X
4c5f7207 698@tab Used in Quake II.
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699@item FLIC format @tab @tab X
700@tab .fli/.flc files
da00f30e 701@item Sierra VMD @tab @tab X
4c5f7207 702@tab Used in Sierra CD-ROM games.
d08d7142 703@item Sierra Online @tab @tab X
4c5f7207 704@tab .sol files used in Sierra Online games.
38088adf 705@item Matroska @tab @tab X
ad81a9fe 706@item Electronic Arts Multimedia @tab @tab X
4c5f7207 707@tab Used in various EA games; files have extensions like WVE and UV2.
353147ed 708@item Nullsoft Video (NSV) format @tab @tab X
4accd1fd 709@item ADTS AAC audio @tab X @tab X
ea395e8c 710@item Creative VOC @tab X @tab X @tab Created for the Sound Blaster Pro.
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711@item American Laser Games MM @tab @tab X
712@tab Multimedia format used in games like Mad Dog McCree
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713@item AVS @tab @tab X
714@tab Multimedia format used by the Creature Shock game.
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715@item Smacker @tab @tab X
716@tab Multimedia format used by many games.
cc0bc648 717@item GXF @tab @tab X
353147ed 718@end multitable
9181577c 719
4c5f7207 720@code{X} means that encoding (resp. decoding) is supported.
9181577c 721
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722@section Image Formats
723
724FFmpeg can read and write images for each frame of a video sequence. The
725following image formats are supported:
726
3fc9e78f 727@multitable @columnfractions .4 .1 .1 .4
0699d2fe 728@item Supported Image Format @tab Encoding @tab Decoding @tab Comments
115329f1 729@item PGM, PPM @tab X @tab X
4c5f7207 730@item PAM @tab X @tab X @tab PAM is a PNM extension with alpha support.
2eb5d024 731@item PGMYUV @tab X @tab X @tab PGM with U and V components in YUV 4:2:0
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732@item JPEG @tab X @tab X @tab Progressive JPEG is not supported.
733@item .Y.U.V @tab X @tab X @tab one raw file per component
734@item animated GIF @tab X @tab X @tab Only uncompressed GIFs are generated.
735@item PNG @tab X @tab X @tab 2 bit and 4 bit/pixel not supported yet.
6a91ec51 736@item SGI @tab X @tab X @tab SGI RGB image format
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737@end multitable
738
4c5f7207 739@code{X} means that encoding (resp. decoding) is supported.
0699d2fe 740
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741@section Video Codecs
742
3fc9e78f 743@multitable @columnfractions .4 .1 .1 .4
9181577c 744@item Supported Codec @tab Encoding @tab Decoding @tab Comments
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745@item MPEG-1 video @tab X @tab X
746@item MPEG-2 video @tab X @tab X
747@item MPEG-4 @tab X @tab X @tab also known as DivX4/5
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748@item MSMPEG4 V1 @tab X @tab X
749@item MSMPEG4 V2 @tab X @tab X
4c5f7207 750@item MSMPEG4 V3 @tab X @tab X @tab also known as DivX3
9181577c 751@item WMV7 @tab X @tab X
4c5f7207 752@item WMV8 @tab X @tab X @tab not completely working
b06b45c4 753@item H.261 @tab X @tab X
4c5f7207 754@item H.263(+) @tab X @tab X @tab also known as RealVideo 1.0
b06b45c4 755@item H.264 @tab @tab X
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756@item RealVideo 1.0 @tab X @tab X
757@item RealVideo 2.0 @tab X @tab X
115329f1 758@item MJPEG @tab X @tab X
4c5f7207 759@item lossless MJPEG @tab X @tab X
26d6d032 760@item JPEG-LS @tab X @tab X @tab fourcc: MJLS, lossless and near-lossless is supported
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761@item Apple MJPEG-B @tab @tab X
762@item Sunplus MJPEG @tab @tab X @tab fourcc: SP5X
115329f1 763@item DV @tab X @tab X
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764@item HuffYUV @tab X @tab X
765@item FFmpeg Video 1 @tab X @tab X @tab experimental lossless codec (fourcc: FFV1)
766@item FFmpeg Snow @tab X @tab X @tab experimental wavelet codec (fourcc: SNOW)
701b603d 767@item Asus v1 @tab X @tab X @tab fourcc: ASV1
4d3b1f8d 768@item Asus v2 @tab X @tab X @tab fourcc: ASV2
701b603d 769@item Creative YUV @tab @tab X @tab fourcc: CYUV
d2bfadc0 770@item Sorenson Video 1 @tab X @tab X @tab fourcc: SVQ1
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771@item Sorenson Video 3 @tab @tab X @tab fourcc: SVQ3
772@item On2 VP3 @tab @tab X @tab still experimental
d6896c49 773@item Theora @tab @tab X @tab still experimental
cdb2c1ca 774@item Intel Indeo 3 @tab @tab X
9303d49c 775@item FLV @tab X @tab X @tab Sorenson H.263 used in Flash
0919e788 776@item Flash Screen Video @tab @tab X @tab fourcc: FSV1
4d3b1f8d 777@item ATI VCR1 @tab @tab X @tab fourcc: VCR1
7fe4c823 778@item ATI VCR2 @tab @tab X @tab fourcc: VCR2
4d3b1f8d 779@item Cirrus Logic AccuPak @tab @tab X @tab fourcc: CLJR
4c5f7207 780@item 4X Video @tab @tab X @tab Used in certain computer games.
115329f1 781@item Sony Playstation MDEC @tab @tab X
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782@item Id RoQ @tab @tab X @tab Used in Quake III, Jedi Knight 2, other computer games.
783@item Xan/WC3 @tab @tab X @tab Used in Wing Commander III .MVE files.
784@item Interplay Video @tab @tab X @tab Used in Interplay .MVE files.
070ed1bc 785@item Apple Animation @tab @tab X @tab fourcc: 'rle '
42cad81a 786@item Apple Graphics @tab @tab X @tab fourcc: 'smc '
2fdf638b 787@item Apple Video @tab @tab X @tab fourcc: rpza
d08d7142 788@item Apple QuickDraw @tab @tab X @tab fourcc: qdrw
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789@item Cinepak @tab @tab X
790@item Microsoft RLE @tab @tab X
791@item Microsoft Video-1 @tab @tab X
4120a53a 792@item Westwood VQA @tab @tab X
4c5f7207 793@item Id Cinematic Video @tab @tab X @tab Used in Quake II.
1dc1ed99 794@item Planar RGB @tab @tab X @tab fourcc: 8BPS
42cad81a 795@item FLIC video @tab @tab X
9a4117d5 796@item Duck TrueMotion v1 @tab @tab X @tab fourcc: DUCK
dce76c20 797@item Duck TrueMotion v2 @tab @tab X @tab fourcc: TM20
4c5f7207 798@item VMD Video @tab @tab X @tab Used in Sierra VMD files.
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799@item MSZH @tab @tab X @tab Part of LCL
800@item ZLIB @tab X @tab X @tab Part of LCL, encoder experimental
9d53d58e 801@item TechSmith Camtasia @tab @tab X @tab fourcc: TSCC
d0a0bbd2 802@item IBM Ultimotion @tab @tab X @tab fourcc: ULTI
ab711b3c 803@item Miro VideoXL @tab @tab X @tab fourcc: VIXL
acfd8f0f 804@item QPEG @tab @tab X @tab fourccs: QPEG, Q1.0, Q1.1
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DB
805@item LOCO @tab @tab X @tab
806@item Winnov WNV1 @tab @tab X @tab
589f8220 807@item Autodesk Animator Studio Codec @tab @tab X @tab fourcc: AASC
115329f1 808@item Fraps FPS1 @tab @tab X @tab
2b6c1d80 809@item CamStudio @tab @tab X @tab fourcc: CSCD
4e114829 810@item American Laser Games Video @tab @tab X @tab Used in games like Mad Dog McCree
9c8d8e84 811@item ZMBV @tab @tab X @tab
26376701 812@item AVS Video @tab @tab X @tab Video encoding used by the Creature Shock game.
348efc18 813@item Smacker Video @tab @tab X @tab Video encoding used in Smacker.
dfca23e3 814@item RTjpeg @tab @tab X @tab Video encoding used in NuppelVideo files.
fd7b1991 815@item KMVC @tab @tab X @tab Codec used in Worms games.
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816@end multitable
817
4c5f7207 818@code{X} means that encoding (resp. decoding) is supported.
9181577c 819
70b0bb87 820See @url{http://mplayerhq.hu/~michael/codec-features.html} to
4c5f7207
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821get a precise comparison of the FFmpeg MPEG-4 codec compared to
822other implementations.
60837265 823
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824@section Audio Codecs
825
826@multitable @columnfractions .4 .1 .1 .1 .7
827@item Supported Codec @tab Encoding @tab Decoding @tab Comments
115329f1 828@item MPEG audio layer 2 @tab IX @tab IX
9181577c 829@item MPEG audio layer 1/3 @tab IX @tab IX
4c5f7207 830@tab MP3 encoding is supported through the external library LAME.
37776c3b 831@item AC3 @tab IX @tab IX
4c5f7207 832@tab liba52 is used internally for decoding.
34d7008d 833@item Vorbis @tab X @tab X
4c5f7207 834@tab Supported through the external library libvorbis.
4745b5bf 835@item WMA V1/V2 @tab @tab X
f6fa7a6c 836@item AAC @tab X @tab X
4c5f7207 837@tab Supported through the external library libfaac/libfaad.
d4c3c5a6 838@item Microsoft ADPCM @tab X @tab X
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839@item MS IMA ADPCM @tab X @tab X
840@item QT IMA ADPCM @tab @tab X
841@item 4X IMA ADPCM @tab @tab X
d4e437df 842@item G.726 ADPCM @tab X @tab X
b17e9c99 843@item Duck DK3 IMA ADPCM @tab @tab X
4c5f7207 844@tab Used in some Sega Saturn console games.
b17e9c99 845@item Duck DK4 IMA ADPCM @tab @tab X
4c5f7207 846@tab Used in some Sega Saturn console games.
2fdf638b 847@item Westwood Studios IMA ADPCM @tab @tab X
4c5f7207 848@tab Used in Westwood Studios games like Command and Conquer.
7d8379f2 849@item SMJPEG IMA ADPCM @tab @tab X
4c5f7207 850@tab Used in certain Loki game ports.
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851@item CD-ROM XA ADPCM @tab @tab X
852@item CRI ADX ADPCM @tab X @tab X
4c5f7207 853@tab Used in Sega Dreamcast games.
7d8379f2 854@item Electronic Arts ADPCM @tab @tab X
4c5f7207 855@tab Used in various EA titles.
b3bfb299 856@item Creative ADPCM @tab @tab X
2433f24f 857@tab 16 -> 4, 8 -> 4, 8 -> 3, 8 -> 2
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858@item RA144 @tab @tab X
859@tab Real 14400 bit/s codec
860@item RA288 @tab @tab X
861@tab Real 28800 bit/s codec
37776c3b 862@item RADnet @tab X @tab IX
4c5f7207 863@tab Real low bitrate AC3 codec, liba52 is used for decoding.
2eb5d024 864@item AMR-NB @tab X @tab X
4c5f7207 865@tab Supported through an external library.
d663a1fd 866@item AMR-WB @tab X @tab X
4c5f7207 867@tab Supported through an external library.
2eb5d024 868@item DV audio @tab @tab X
4d3b1f8d 869@item Id RoQ DPCM @tab @tab X
4c5f7207 870@tab Used in Quake III, Jedi Knight 2, other computer games.
4d3b1f8d 871@item Interplay MVE DPCM @tab @tab X
4c5f7207 872@tab Used in various Interplay computer games.
b17e9c99 873@item Xan DPCM @tab @tab X
4c5f7207 874@tab Used in Origin's Wing Commander IV AVI files.
d08d7142 875@item Sierra Online DPCM @tab @tab X
4c5f7207 876@tab Used in Sierra Online game audio files.
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877@item Apple MACE 3 @tab @tab X
878@item Apple MACE 6 @tab @tab X
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879@item FLAC lossless audio @tab @tab X
880@item Shorten lossless audio @tab @tab X
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881@item Apple lossless audio @tab @tab X
882@tab QuickTime fourcc 'alac'
33a4d8b1 883@item FFmpeg Sonic @tab X @tab X
4c5f7207 884@tab experimental lossy/lossless codec
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RT
885@item Qdesign QDM2 @tab @tab X
886@tab there are still some distortions
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887@item Real COOK @tab @tab X
888@tab All versions except 5.1 are supported
e839a994 889@item DSP Group TrueSpeech @tab @tab X
3dc411c0 890@item True Audio (TTA) @tab @tab X
348efc18 891@item Smacker Audio @tab @tab X
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892@end multitable
893
4c5f7207 894@code{X} means that encoding (resp. decoding) is supported.
9181577c 895
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896@code{I} means that an integer-only version is available, too (ensures high
897performance on systems without hardware floating point support).
9181577c 898
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899@chapter Platform Specific information
900
901@section Linux
902
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903FFmpeg should be compiled with at least GCC 2.95.3. GCC 3.2 is the
904preferred compiler now for FFmpeg. All future optimizations will depend on
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905features only found in GCC 3.2.
906
907@section BSD
908
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909BSD make will not build FFmpeg, you need to install and use GNU Make
910(@file{gmake}).
911
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912@section Windows
913
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914@subsection Native Windows compilation
915
916@itemize
917@item Install the current versions of MSYS and MinGW from
918@url{http://www.mingw.org/}. You can find detailed installation
919instructions in the download section and the FAQ.
920
4c5f7207 921@item If you want to test the FFplay, also download
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922the MinGW development library of SDL 1.2.x
923(@file{SDL-devel-1.2.x-mingw32.tar.gz}) from
4c5f7207 924@url{http://www.libsdl.org}. Unpack it in a temporary directory, and
50f52fcd 925unpack the archive @file{i386-mingw32msvc.tar.gz} in the MinGW tool
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FB
926directory. Edit the @file{sdl-config} script so that it gives the
927correct SDL directory when invoked.
50f52fcd 928
e926e391 929@item Extract the current version of FFmpeg.
115329f1 930
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931@item Start the MSYS shell (file @file{msys.bat}).
932
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933@item Change to the FFmpeg directory and follow
934 the instructions of how to compile FFmpeg (file
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935@file{INSTALL}). Usually, launching @file{./configure} and @file{make}
936suffices. If you have problems using SDL, verify that
937@file{sdl-config} can be launched from the MSYS command line.
938
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939@item You can install FFmpeg in @file{Program Files/FFmpeg} by typing
940@file{make install}. Don't forget to copy @file{SDL.dll} to the place
941you launch @file{ffplay} from.
50f52fcd 942
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943@end itemize
944
115329f1 945Notes:
988a9f9e 946@itemize
50f52fcd 947
988a9f9e
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948@item The target @file{make wininstaller} can be used to create a
949Nullsoft based Windows installer for FFmpeg and FFplay. @file{SDL.dll}
4c5f7207 950must be copied to the FFmpeg directory in order to build the
988a9f9e
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951installer.
952
4c5f7207 953@item By using @code{./configure --enable-shared} when configuring FFmpeg,
988a9f9e
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954you can build @file{avcodec.dll} and @file{avformat.dll}. With
955@code{make install} you install the FFmpeg DLLs and the associated
115329f1 956headers in @file{Program Files/FFmpeg}.
988a9f9e 957
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958@item Visual C++ compatibility: If you used @code{./configure --enable-shared}
959when configuring FFmpeg, FFmpeg tries to use the Microsoft Visual
988a9f9e 960C++ @code{lib} tool to build @code{avcodec.lib} and
4c5f7207 961@code{avformat.lib}. With these libraries you can link your Visual C++
be0efc0c 962code directly with the FFmpeg DLLs (see below).
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963
964@end itemize
b030b284 965
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966@subsection Visual C++ compatibility
967
968FFmpeg will not compile under Visual C++ -- and it has too many
969dependencies on the GCC compiler to make a port viable. However,
970if you want to use the FFmpeg libraries in your own applications,
971you can still compile those applications using Visual C++. An
972important restriction to this is that you have to use the
973dynamically linked versions of the FFmpeg libraries (i.e. the
974DLLs), and you have to make sure that Visual-C++-compatible
975import libraries are created during the FFmpeg build process.
976
977This description of how to use the FFmpeg libraries with Visual C++ is
978based on Visual C++ 2005 Express Edition Beta 2. If you have a different
979version, you might have to modify the procedures slightly.
980
981Here are the step-by-step instructions for building the FFmpeg libraries
982so they can be used with Visual C++:
983
984@enumerate
985
986@item Install Visual C++ (if you haven't done so already).
987
988@item Install MinGW and MSYS as described above.
989
990@item Add a call to @file{vcvars32.bat} (which sets up the environment
991variables for the Visual C++ tools) as the first line of
992@file{msys.bat}. The standard location for @file{vcvars32.bat} is
993@file{C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat},
994and the standard location for @file{msys.bat} is
995@file{C:\msys\1.0\msys.bat}. If this corresponds to your setup, add the
996following line as the first line of @file{msys.bat}:
997
998@code{call "C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat"}
999
1000@item Start the MSYS shell (file @file{msys.bat}) and type @code{link.exe}.
1001If you get a help message with the command line options of @code{link.exe},
1002this means your environment variables are set up correctly, the
1003Microsoft linker is on the path and will be used by FFmpeg to
1004create Visual-C++-compatible import libraries.
1005
e926e391 1006@item Extract the current version of FFmpeg and change to the FFmpeg directory.
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1007
1008@item Type the command
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1009@code{./configure --enable-shared --disable-static --enable-memalign-hack}
1010to configure and, if that didn't produce any errors,
1011type @code{make} to build FFmpeg.
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1012
1013@item The subdirectories @file{libavformat}, @file{libavcodec}, and
1014@file{libavutil} should now contain the files @file{avformat.dll},
1015@file{avformat.lib}, @file{avcodec.dll}, @file{avcodec.lib},
1016@file{avutil.dll}, and @file{avutil.lib}, respectively. Copy the three
1017DLLs to your System32 directory (typically @file{C:\Windows\System32}).
1018
1019@end enumerate
1020
1021And here is how to use these libraries with Visual C++:
1022
1023@enumerate
1024
1025@item Create a new console application ("File / New / Project") and then
1026select "Win32 Console Application". On the appropriate page of the
1027Application Wizard, uncheck the "Precompiled headers" option.
1028
1029@item Write the source code for your application, or, for testing, just
1030copy the code from an existing sample application into the source file
1031that Visual C++ has already created for you. (Note that your source
1032filehas to have a @code{.cpp} extension; otherwise, Visual C++ won't
1033compile the FFmpeg headers correctly because in C mode, it doesn't
1034recognize the @code{inline} keyword.) For example, you can copy
1035@file{output_example.c} from the FFmpeg distribution (but you will
1036have to make minor modifications so the code will compile under
1037C++, see below).
1038
1039@item Open the "Project / Properties" dialog box. In the "Configuration"
1040combo box, select "All Configurations" so that the changes you make will
1041affect both debug and release builds. In the tree view on the left hand
1042side, select "C/C++ / General", then edit the "Additional Include
1043Directories" setting to contain the complete paths to the
1044@file{libavformat}, @file{libavcodec}, and @file{libavutil}
1045subdirectories of your FFmpeg directory. Note that the directories have
1046to be separated using semicolons. Now select "Linker / General" from the
1047tree view and edit the "Additional Library Directories" setting to
1048contain the same three directories.
1049
1050@item Still in the "Project / Properties" dialog box, select "Linker / Input"
1051from the tree view, then add the files @file{avformat.lib},
1052@file{avcodec.lib}, and @file{avutil.lib} to the end of the "Additional
1053Dependencies". Note that the names of the libraries have to be separated
1054using spaces.
1055
765c3440 1056@item Now, select "C/C++ / Code Generation" from the tree view. Select
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1057"Debug" in the "Configuration" combo box. Make sure that "Runtime
1058Library" is set to "Multi-threaded Debug DLL". Then, select "Release" in
1059the "Configuration" combo box and make sure that "Runtime Library" is
1060set to "Multi-threaded DLL".
1061
1062@item Click "OK" to close the "Project / Properties" dialog box and build
1063the application. Hopefully, it should compile and run cleanly. If you
1064used @file{output_example.c} as your sample application, you will get a
1065few compiler errors, but they are easy to fix. The first type of error
1066occurs because Visual C++ doesn't allow an @code{int} to be converted to
1067an @code{enum} without a cast. To solve the problem, insert the required
1068casts (this error occurs once for a @code{CodecID} and once for a
1069@code{CodecType}). The second type of error occurs because C++ requires
1070the return value of @code{malloc} to be cast to the exact type of the
1071pointer it is being assigned to. Visual C++ will complain that, for
1072example, @code{(void *)} is being assigned to @code{(uint8_t *)} without
1073an explicit cast. So insert an explicit cast in these places to silence
1074the compiler. The third type of error occurs because the @code{snprintf}
1075library function is called @code{_snprintf} under Visual C++. So just
1076add an underscore to fix the problem. With these changes,
1077@file{output_example.c} should compile under Visual C++, and the
1078resulting executable should produce valid video files.
1079
1080@end enumerate
1081
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1082@subsection Cross compilation for Windows with Linux
1083
1084You must use the MinGW cross compilation tools available at
1085@url{http://www.mingw.org/}.
1086
4c5f7207 1087Then configure FFmpeg with the following options:
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1088@example
1089./configure --enable-mingw32 --cross-prefix=i386-mingw32msvc-
1090@end example
019c8838 1091(you can change the cross-prefix according to the prefix chosen for the
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1092MinGW tools).
1093
4c5f7207 1094Then you can easily test FFmpeg with Wine
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1095(@url{http://www.winehq.com/}).
1096
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1097@subsection Compilation under Cygwin
1098
1099Cygwin works very much like Unix.
1100
1101Just install your Cygwin with all the "Base" packages, plus the
1102following "Devel" ones:
1103@example
1104binutils, gcc-core, make, subversion
1105@end example
1106
1107Do not install binutils-20060709-1 (they are buggy on shared builds);
1108use binutils-20050610-1 instead.
1109
1110Then run
1111
1112@example
1113./configure --enable-static --disable-shared
1114@end example
1115
1116to make a static build or
1117
1118@example
1119./configure --enable-shared --disable-static
1120@end example
1121
1122to build shared libraries.
1123
1124If you want to build FFmpeg with additional libraries, download Cygwin
1125"Devel" packages for Ogg and Vorbis from any Cygwin packages repository
1126and/or SDL, xvid, faac, faad2 packages from Cygwin Ports,
1127(@url{http://cygwinports.dotsrc.org/}).
1128
1129@subsection Crosscompilation for Windows under Cygwin
1130
1131With Cygwin you can create Windows binaries that don't need the cygwin1.dll.
1132
1133Just install your Cygwin as explained before, plus these additional
1134"Devel" packages:
1135@example
1136gcc-mingw-core, mingw-runtime, mingw-zlib
1137@end example
1138
1139and add some special flags to your configure invocation.
1140
1141For a static build run
1142@example
1143./configure --enable-mingw32 --enable-memalign-hack --enable-static --disable-shared --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
1144@end example
1145
1146and for a build with shared libraries
1147@example
1148./configure --enable-mingw32 --enable-memalign-hack --enable-shared --disable-static --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
1149@end example
1150
019c8838 1151@section Mac OS X
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1152
1153@section BeOS
1154
1155The configure script should guess the configuration itself.
1156Networking support is currently not finished.
1157errno issues fixed by Andrew Bachmann.
1158
1159Old stuff:
1160
7dd611c9 1161François Revol - revol at free dot fr - April 2002
47d944d2 1162
115329f1 1163The configure script should guess the configuration itself,
4c5f7207 1164however I still didn't test building on the net_server version of BeOS.
47d944d2 1165
4c5f7207 1166FFserver is broken (needs poll() implementation).
47d944d2 1167
4c5f7207 1168There are still issues with errno codes, which are negative in BeOS, and
115329f1 1169that FFmpeg negates when returning. This ends up turning errors into
47d944d2
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1170valid results, then crashes.
1171(To be fixed)
1172
34d7008d 1173@chapter Developers Guide
9181577c
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1174
1175@section API
a0b72f90 1176@itemize @bullet
9181577c 1177@item libavcodec is the library containing the codecs (both encoding and
4c5f7207 1178decoding). Look at @file{libavcodec/apiexample.c} to see how to use it.
9181577c 1179
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1180@item libavformat is the library containing the file format handling (mux and
1181demux code for several formats). Look at @file{ffplay.c} to use it in a
a93b9dba
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1182player. See @file{output_example.c} to use it to generate audio or video
1183streams.
1184
9181577c
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1185@end itemize
1186
1187@section Integrating libavcodec or libavformat in your program
1188
1189You can integrate all the source code of the libraries to link them
1190statically to avoid any version problem. All you need is to provide a
1191'config.mak' and a 'config.h' in the parent directory. See the defines
1192generated by ./configure to understand what is needed.
1193
1194You can use libavcodec or libavformat in your commercial program, but
1195@emph{any patch you make must be published}. The best way to proceed is
4c5f7207 1196to send your patches to the FFmpeg mailing list.
9181577c 1197
80d1c272 1198@node Coding Rules
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1199@section Coding Rules
1200
4c5f7207 1201FFmpeg is programmed in the ISO C90 language with a few additional
cb6e87c1
FH
1202features from ISO C99, namely:
1203@itemize @bullet
1204@item
1205the @samp{inline} keyword;
1206@item
1207@samp{//} comments;
1208@item
1209designated struct initializers (@samp{struct s x = @{ .i = 17 @};})
1210@item
114afa9c 1211compound literals (@samp{x = (struct s) @{ 17, 23 @};})
cb6e87c1
FH
1212@end itemize
1213
1214These features are supported by all compilers we care about, so we won't
1215accept patches to remove their use unless they absolutely don't impair
1216clarity and performance.
1217
4c5f7207 1218All code must compile with GCC 2.95 and GCC 3.3. Currently, FFmpeg also
cb6e87c1
FH
1219compiles with several other compilers, such as the Compaq ccc compiler
1220or Sun Studio 9, and we would like to keep it that way unless it would
1221be exceedingly involved. To ensure compatibility, please don't use any
4c5f7207 1222additional C99 features or GCC extensions. Especially watch out for:
cb6e87c1
FH
1223@itemize @bullet
1224@item
1225mixing statements and declarations;
1226@item
1227@samp{long long} (use @samp{int64_t} instead);
1228@item
1229@samp{__attribute__} not protected by @samp{#ifdef __GNUC__} or similar;
1230@item
019c8838 1231GCC statement expressions (@samp{(x = (@{ int y = 4; y; @})}).
cb6e87c1 1232@end itemize
9181577c 1233
53862e0f 1234Indent size is 4.
b86e38a0 1235The presentation is the one specified by 'indent -i4 -kr -nut'.
53862e0f
DB
1236The TAB character is forbidden outside of Makefiles as is any
1237form of trailing whitespace. Commits containing either will be
1c1b5a40 1238rejected by the Subversion repository.
9181577c 1239
4c5f7207 1240Main priority in FFmpeg is simplicity and small code size (=less
9181577c
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1241bugs).
1242
4c5f7207
DB
1243Comments: Use the JavaDoc/Doxygen
1244format (see examples below) so that code documentation
1245can be generated automatically. All nontrivial functions should have a comment
1246above them explaining what the function does, even if it's just one sentence.
1247All structures and their member variables should be documented, too.
f4888b83
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1248@example
1249/**
2185824b
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1250 * @@file mpeg.c
1251 * MPEG codec.
1252 * @@author ...
1253 */
f4888b83
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1254
1255/**
2185824b
MR
1256 * Summary sentence.
1257 * more text ...
1258 * ...
1259 */
114afa9c 1260typedef struct Foobar@{
2185824b
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1261 int var1; /**< var1 description */
1262 int var2; ///< var2 description
1263 /** var3 description */
1264 int var3;
114afa9c 1265@} Foobar;
f4888b83
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1266
1267/**
2185824b
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1268 * Summary sentence.
1269 * more text ...
1270 * ...
1271 * @@param my_parameter description of my_parameter
1272 * @@return return value description
1273 */
f4888b83
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1274int myfunc(int my_parameter)
1275...
1276@end example
9181577c 1277
115329f1 1278fprintf and printf are forbidden in libavformat and libavcodec,
36d9b4e8
MN
1279please use av_log() instead.
1280
1c1b5a40 1281@section Development Policy
7a57b90c
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1282
1283@enumerate
115329f1 1284@item
7a57b90c 1285 You must not commit code which breaks FFmpeg! (Meaning unfinished but
4c5f7207 1286 enabled code which breaks compilation or compiles but does not work or
7a57b90c
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1287 breaks the regression tests)
1288 You can commit unfinished stuff (for testing etc), but it must be disabled
1289 (#ifdef etc) by default so it does not interfere with other developers'
1290 work.
115329f1 1291@item
7a57b90c 1292 You don't have to over-test things. If it works for you, and you think it
4c5f7207
DB
1293 should work for others, then commit. If your code has problems
1294 (portability, triggers compiler bugs, unusual environment etc) they will be
7a57b90c 1295 reported and eventually fixed.
115329f1 1296@item
7a57b90c
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1297 Do not commit unrelated changes together, split them into self-contained
1298 pieces.
1299@item
1300 Do not change behavior of the program (renaming options etc) without
019c8838 1301 first discussing it on the ffmpeg-devel mailing list. Do not remove
7a57b90c 1302 functionality from the code. Just improve!
115329f1 1303
4c5f7207 1304 Note: Redundant code can be removed.
7a57b90c
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1305@item
1306 Do not commit changes to the build system (Makefiles, configure script)
019c8838 1307 which change behavior, defaults etc, without asking first. The same
7a57b90c
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1308 applies to compiler warning fixes, trivial looking fixes and to code
1309 maintained by other developers. We usually have a reason for doing things
019c8838 1310 the way we do. Send your changes as patches to the ffmpeg-devel mailing
7a57b90c
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1311 list, and if the code maintainers say OK, you may commit. This does not
1312 apply to files you wrote and/or maintain.
1313@item
1314 We refuse source indentation and other cosmetic changes if they are mixed
1315 with functional changes, such commits will be rejected and removed. Every
1316 developer has his own indentation style, you should not change it. Of course
1317 if you (re)write something, you can use your own style, even though we would
4c5f7207
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1318 prefer if the indentation throughout FFmpeg was consistent (Many projects
1319 force a given indentation style - we don't.). If you really need to make
7a57b90c
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1320 indentation changes (try to avoid this), separate them strictly from real
1321 changes.
1322
114afa9c 1323 NOTE: If you had to put if()@{ .. @} over a large (> 5 lines) chunk of code,
115329f1 1324 then either do NOT change the indentation of the inner part within (don't
019c8838 1325 move it to the right)! or do so in a separate commit
7a57b90c
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1326@item
1327 Always fill out the commit log message. Describe in a few lines what you
1328 changed and why. You can refer to mailing list postings if you fix a
1329 particular bug. Comments such as "fixed!" or "Changed it." are unacceptable.
1330@item
1331 If you apply a patch by someone else, include the name and email address in
1c1b5a40 1332 the log message. Since the ffmpeg-cvslog mailing list is publicly
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DB
1333 archived you should add some SPAM protection to the email address. Send an
1334 answer to ffmpeg-devel (or wherever you got the patch from) saying that
7a57b90c
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1335 you applied the patch.
1336@item
5ab0f204
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1337 Do NOT commit to code actively maintained by others without permission.
1338 Send a patch to ffmpeg-devel instead. If noone answers within a reasonable
1339 timeframe (12h for build failures and security fixes, 3 days small changes,
1340 1 week for big patches) then commit your patch if you think it's OK.
1341 Also note, the maintainer can simply ask for more time to review!
7a57b90c 1342@item
1c1b5a40 1343 Subscribe to the ffmpeg-cvslog mailing list. The diffs of all commits
7a57b90c
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1344 are sent there and reviewed by all the other developers. Bugs and possible
1345 improvements or general questions regarding commits are discussed there. We
1346 expect you to react if problems with your code are uncovered.
1347@item
1348 Update the documentation if you change behavior or add features. If you are
019c8838 1349 unsure how best to do this, send a patch to ffmpeg-devel, the documentation
7a57b90c
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1350 maintainer(s) will review and commit your stuff.
1351@item
4c5f7207
DB
1352 Never write to unallocated memory, never write over the end of arrays,
1353 always check values read from some untrusted source before using them
1354 as array index or other risky things.
76bec1d8
AS
1355@item
1356 Remember to check if you need to bump versions for the specific libav
f0efbde7 1357 parts (libavutil, libavcodec, libavformat) you are changing. You need
76bec1d8
AS
1358 to change the version integer and the version string.
1359 Incrementing the first component means no backward compatibility to
f0efbde7 1360 previous versions (e.g. removal of a function).
76bec1d8
AS
1361 Incrementing the second component means backward compatible change
1362 (e.g. addition of a function).
1363 Incrementing the third component means a noteworthy binary compatible
1364 change (e.g. encoder bug fix that matters for the decoder).
ebd32fd7 1365@item
3f1965c4
DB
1366 If you add a new codec, remember to update the changelog, add it to
1367 the supported codecs table in the documentation and bump the second
1368 component of the @file{libavcodec} version number appropriately. If
1369 it has a fourcc, add it to @file{libavformat/avienc.c}, even if it
1370 is only a decoder.
114afa9c 1371@end enumerate
7a57b90c
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1372
1373We think our rules are not too hard. If you have comments, contact us.
1374
1375Note, these rules are mostly borrowed from the MPlayer project.
1376
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1377@section Submitting patches
1378
80d1c272
MN
1379First, (@pxref{Coding Rules}) above if you didn't yet.
1380
6a6810b1 1381When you submit your patch, try to send a unified diff (diff '-up'
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1382option). I cannot read other diffs :-)
1383
6e5c1877 1384Also please do not submit patches which contain several unrelated changes.
115329f1 1385Split them into individual self-contained patches; this makes reviewing
7885603a
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1386them much easier.
1387
9181577c 1388Run the regression tests before submitting a patch so that you can
6bf40f39 1389verify that there are no big problems.
9181577c 1390
9181577c 1391Patches should be posted as base64 encoded attachments (or any other
4c5f7207 1392encoding which ensures that the patch won't be trashed during
115329f1 1393transmission) to the ffmpeg-devel mailing list, see
2b165e29 1394@url{http://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel}
9181577c 1395
54fcf429 1396It also helps quite a bit if you tell us what the patch does (for example
4c5f7207 1397'replaces lrint by lrintf'), and why (for example '*BSD isn't C99 compliant
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1398and has no lrint()')
1399
4c5f7207
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1400We reply to all submitted patches and either apply or reject with some
1401explanation why, but sometimes we are quite busy so it can take a week or two.
cf7f2b16 1402
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1403@section Regression tests
1404
1c1b5a40 1405Before submitting a patch (or committing to the repository), you should at least
9181577c
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1406test that you did not break anything.
1407
4c5f7207
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1408The regression tests build a synthetic video stream and a synthetic
1409audio stream. These are then encoded and decoded with all codecs or
9181577c 1410formats. The CRC (or MD5) of each generated file is recorded in a
4c5f7207 1411result file. A 'diff' is launched to compare the reference results and
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1412the result file.
1413
4c5f7207 1414The regression tests then go on to test the FFserver code with a
6bf40f39
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1415limited set of streams. It is important that this step runs correctly
1416as well.
1417
36d9b4e8 1418Run 'make test' to test all the codecs and formats.
9181577c 1419
4c5f7207 1420Run 'make fulltest' to test all the codecs, formats and FFserver.
9181577c 1421
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1422[Of course, some patches may change the results of the regression tests. In
1423this case, the reference results of the regression tests shall be modified
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1424accordingly].
1425
1426@bye