Attempt to better explain how to split patches into individual
[libav.git] / doc / ffmpeg-doc.texi
CommitLineData
9181577c
FB
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
4c5f7207
DB
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.
9181577c
FB
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
9181577c
FB
27@section Video and Audio grabbing
28
cc58300e
RP
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
9181577c
FB
34@end example
35
e99c4e10 36Note that you must activate the right video source and channel before
4c5f7207
DB
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
76d2efda
BC
42@section X11 grabbing
43
913e4081 44FFmpeg can grab the X11 display.
76d2efda
BC
45
46@example
9e0ab666 47ffmpeg -f x11grab -s cif -i :0.0 /tmp/out.mpg
76d2efda
BC
48@end example
49
913e4081
DB
500.0 is display.screen number of your X11 server, same as
51the DISPLAY environment variable.
76d2efda 52
0cd4faf9 53@example
9e0ab666 54ffmpeg -f x11grab -s cif -i :0.0+10,20 /tmp/out.mpg
0cd4faf9
PI
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:
9181577c
FB
63
64Examples:
65
4c5f7207 66* You can use YUV files as input:
9181577c
FB
67
68@example
115329f1 69ffmpeg -i /tmp/test%d.Y /tmp/out.mpg
9181577c
FB
70@end example
71
115329f1 72It will use the files:
9181577c 73@example
e99c4e10
FB
74/tmp/test0.Y, /tmp/test0.U, /tmp/test0.V,
75/tmp/test1.Y, /tmp/test1.U, /tmp/test1.V, etc...
9181577c
FB
76@end example
77
e99c4e10
FB
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:
9181577c
FB
84
85@example
e99c4e10 86ffmpeg -i /tmp/test.yuv /tmp/out.avi
9181577c
FB
87@end example
88
4c5f7207
DB
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:
9181577c
FB
94
95@example
f926cbe7 96ffmpeg -i mydivx.avi hugefile.yuv
9181577c
FB
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
9181577c
FB
103@end example
104
4c5f7207
DB
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:
9181577c
FB
109
110@example
e99c4e10 111ffmpeg -i /tmp/a.wav -ar 22050 /tmp/a.mp2
9181577c
FB
112@end example
113
4c5f7207 114Converts a.wav to MPEG audio at 22050Hz sample rate.
9181577c
FB
115
116* You can encode to several formats at the same time and define a
e99c4e10 117mapping from input stream to output streams:
9181577c
FB
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
9181577c
FB
121@end example
122
4c5f7207
DB
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.
9181577c
FB
126
127* You can transcode decrypted VOBs
128
129@example
7b900f2d 130ffmpeg -i snatch_1.vob -f avi -vcodec mpeg4 -b 800k -g 300 -bf 2 -acodec libmp3lame -ab 128k snatch.avi
9181577c
FB
131@end example
132
4c5f7207
DB
133This is a typical DVD ripping example; the input is a VOB file, the
134output an AVI file with MPEG-4 video and MP3 audio. Note that in this
135command we use B-frames so the MPEG-4 stream is DivX5 compatible, and
136GOP size is 300 which means one intra frame every 10 seconds for 29.97fps
137input video. Furthermore, the audio stream is MP3-encoded so you need
1cc60c47 138to enable LAME support by passing @code{--enable-libmp3lame} to configure.
4c5f7207 139The mapping is particularly useful for DVD transcoding
e99c4e10 140to get the desired audio language.
9181577c 141
4c5f7207 142NOTE: To see the supported input formats, use @code{ffmpeg -formats}.
e99c4e10 143@c man end
9181577c
FB
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
699e77b1
VP
160then applied to the next input or output file.
161
eb10acec 162* To set the video bitrate of the output file to 64kbit/s:
699e77b1
VP
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
4c5f7207
DB
184By default, FFmpeg tries to convert as losslessly as possible: It
185uses the same audio and video parameters for the outputs as the one
e99c4e10
FB
186specified for the inputs.
187@c man end
9181577c 188
e99c4e10 189@c man begin OPTIONS
9181577c
FB
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
4386f941
DB
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
4c5f7207
DB
215Set the recording time in seconds.
216@code{hh:mm:ss[.xxx]} syntax is also supported.
9181577c 217
4386f941
DB
218@item -fs limit_size
219Set the file size limit.
220
e83a84ac 221@item -ss position
4c5f7207
DB
222Seek to given time position in seconds.
223@code{hh:mm:ss[.xxx]} syntax is also supported.
e83a84ac 224
4386f941
DB
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
4386f941
DB
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
4386f941
DB
248@item -album string
249Set the album.
250
ec1b10f4
PI
251@item -track number
252Set the track.
253
254@item -year number
255Set the year.
256
4386f941
DB
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",
4c5f7207
DB
262"ntsc-svcd", ... ). All the format options (bitrate, codecs,
263buffer sizes) are then set automatically. You can just type:
99db6420
FB
264
265@example
266ffmpeg -i myfile.avi -target vcd /tmp/vcd.mpg
267@end example
268
4c5f7207
DB
269Nevertheless you can specify additional options as long as you know
270they do not conflict with the standard, as in:
791d8d1d
MB
271
272@example
273ffmpeg -i myfile.avi -target vcd -bf 2 /tmp/vcd.mpg
274@end example
275
4386f941
DB
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
9181577c
FB
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).
4386f941
DB
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
18bff752
FB
303@item sqcif
304128x96
305@item qcif
306176x144
307@item cif
308352x288
309@item 4cif
310704x576
7d88b5ca
BF
311@item qqvga
312160x120
313@item qvga
314320x240
315@item vga
316640x480
317@item svga
318800x600
319@item xga
3201024x768
321@item uxga
3221600x1200
323@item qxga
3242048x1536
325@item sxga
3261280x1024
327@item qsxga
3282560x2048
329@item hsxga
3305120x4096
331@item wvga
332852x480
333@item wxga
3341366x768
335@item wsxga
3361600x1024
337@item wuxga
3381920x1200
339@item woxga
3402560x1600
341@item wqsxga
3423200x2048
343@item wquxga
3443840x2400
345@item whsxga
3466400x4096
347@item whuxga
3487680x4800
349@item cga
350320x200
351@item ega
352640x350
353@item hd480
354852x480
355@item hd720
3561280x720
357@item hd1080
3581920x1080
18bff752
FB
359@end table
360
361@item -aspect aspect
4c5f7207 362Set aspect ratio (4:3, 16:9 or 1.3333, 1.7777).
18bff752 363@item -croptop size
4c5f7207 364Set top crop band size (in pixels).
18bff752 365@item -cropbottom size
4c5f7207 366Set bottom crop band size (in pixels).
18bff752 367@item -cropleft size
4c5f7207 368Set left crop band size (in pixels).
18bff752 369@item -cropright size
4c5f7207 370Set right crop band size (in pixels).
1ff93ffc 371@item -padtop size
4c5f7207 372Set top pad band size (in pixels).
1ff93ffc 373@item -padbottom size
4c5f7207 374Set bottom pad band size (in pixels).
1ff93ffc 375@item -padleft size
4c5f7207 376Set left pad band size (in pixels).
1ff93ffc 377@item -padright size
4c5f7207 378Set right pad band size (in pixels).
5b79a73e 379@item -padcolor (hex color)
4c5f7207
DB
380Set color of padded bands. The value for padcolor is expressed
381as a six digit hexadecimal number where the first two digits
382represent red, the middle two digits green and last two digits
383blue (default = 000000 (black)).
9181577c 384@item -vn
4c5f7207 385Disable video recording.
115329f1 386@item -bt tolerance
dc5ee8bc 387Set video bitrate tolerance (in bit/s).
18bff752 388@item -maxrate bitrate
f754bfb9 389Set max video bitrate (in bit/s).
18bff752 390@item -minrate bitrate
f754bfb9 391Set min video bitrate (in bit/s).
18bff752 392@item -bufsize size
fa78d895 393Set video buffer verifier buffer size (in bits).
115329f1 394@item -vcodec codec
4c5f7207 395Force video codec to @var{codec}. Use the @code{copy} special value to
5ee03c86 396tell that the raw codec data must be copied as is.
18bff752 397@item -sameq
4c5f7207 398Use same video quality as source (implies VBR).
9181577c 399
115329f1 400@item -pass n
4c5f7207
DB
401Select the pass number (1 or 2). It is useful to do two pass
402encoding. The statistics of the video are recorded in the first
403pass and the video is generated at the exact requested bitrate
404in the second pass.
9181577c 405
115329f1 406@item -passlogfile file
4c5f7207 407Set two pass logfile name to @var{file}.
9181577c 408
4386f941
DB
409@item -newvideo
410Add a new video stream to the current output stream.
411
9181577c
FB
412@end table
413
18bff752 414@section Advanced Video Options
9181577c 415
e99c4e10 416@table @option
4386f941 417@item -pix_fmt format
c3b95b1d
SS
418Set pixel format. Use 'list' as parameter to show all the supported
419pixel formats.
35926489
IP
420@item -sws_flags flags
421Set SwScaler flags (only available when compiled with SwScaler support).
115329f1 422@item -g gop_size
4c5f7207 423Set the group of pictures size.
115329f1 424@item -intra
4c5f7207 425Use only intra frames.
4386f941
DB
426@item -vdt n
427Discard threshold.
115329f1 428@item -qscale q
4bef236b 429Use fixed video quantizer scale (VBR).
115329f1 430@item -qmin q
4bef236b 431minimum video quantizer scale (VBR)
115329f1 432@item -qmax q
4bef236b 433maximum video quantizer scale (VBR)
115329f1 434@item -qdiff q
4bef236b 435maximum difference between the quantizer scales (VBR)
115329f1 436@item -qblur blur
4bef236b 437video quantizer scale blur (VBR)
115329f1 438@item -qcomp compression
4bef236b 439video quantizer scale compression (VBR)
18bff752 440
9ae711e1
VP
441@item -lmin lambda
442minimum video lagrange factor (VBR)
443@item -lmax lambda
444max video lagrange factor (VBR)
445@item -mblmin lambda
446minimum macroblock quantizer scale (VBR)
447@item -mblmax lambda
448maximum macroblock quantizer scale (VBR)
449
450These four options (lmin, lmax, mblmin, mblmax) use 'lambda' units,
451but you may use the QP2LAMBDA constant to easily convert from 'q' units:
452@example
453ffmpeg -i src.ext -lmax 21*QP2LAMBDA dst.ext
454@end example
455
18bff752 456@item -rc_init_cplx complexity
4c5f7207 457initial complexity for single pass encoding
18bff752 458@item -b_qfactor factor
4c5f7207 459qp factor between P- and B-frames
18bff752 460@item -i_qfactor factor
4c5f7207 461qp factor between P- and I-frames
18bff752 462@item -b_qoffset offset
4c5f7207 463qp offset between P- and B-frames
18bff752 464@item -i_qoffset offset
4c5f7207 465qp offset between P- and I-frames
18bff752 466@item -rc_eq equation
4c5f7207
DB
467Set rate control equation (@pxref{FFmpeg formula
468evaluator}) (default = @code{tex^qComp}).
5ee03c86
FB
469@item -rc_override override
470rate control override for specific intervals
c0de00da 471@item -me_method method
4c5f7207
DB
472Set motion estimation method to @var{method}.
473Available methods are (from lowest to best quality):
18bff752
FB
474@table @samp
475@item zero
5ee03c86 476Try just the (0, 0) vector.
18bff752
FB
477@item phods
478@item log
479@item x1
c0de00da
SS
480@item hex
481@item umh
18bff752
FB
482@item epzs
483(default method)
484@item full
485exhaustive search (slow and marginally better than epzs)
486@end table
487
488@item -dct_algo algo
4c5f7207 489Set DCT algorithm to @var{algo}. Available values are:
18bff752
FB
490@table @samp
491@item 0
492FF_DCT_AUTO (default)
493@item 1
494FF_DCT_FASTINT
495@item 2
496FF_DCT_INT
497@item 3
498FF_DCT_MMX
499@item 4
500FF_DCT_MLIB
501@item 5
502FF_DCT_ALTIVEC
503@end table
504
505@item -idct_algo algo
4c5f7207 506Set IDCT algorithm to @var{algo}. Available values are:
18bff752
FB
507@table @samp
508@item 0
509FF_IDCT_AUTO (default)
510@item 1
115329f1 511FF_IDCT_INT
18bff752 512@item 2
115329f1 513FF_IDCT_SIMPLE
18bff752 514@item 3
115329f1 515FF_IDCT_SIMPLEMMX
18bff752 516@item 4
115329f1 517FF_IDCT_LIBMPEG2MMX
18bff752 518@item 5
115329f1 519FF_IDCT_PS2
18bff752 520@item 6
115329f1 521FF_IDCT_MLIB
18bff752 522@item 7
115329f1 523FF_IDCT_ARM
18bff752 524@item 8
115329f1 525FF_IDCT_ALTIVEC
18bff752 526@item 9
115329f1 527FF_IDCT_SH4
18bff752 528@item 10
115329f1 529FF_IDCT_SIMPLEARM
18bff752
FB
530@end table
531
532@item -er n
4c5f7207 533Set error resilience to @var{n}.
18bff752 534@table @samp
115329f1 535@item 1
1471c6c2 536FF_ER_CAREFUL (default)
18bff752 537@item 2
5ee03c86 538FF_ER_COMPLIANT
18bff752
FB
539@item 3
540FF_ER_AGGRESSIVE
541@item 4
542FF_ER_VERY_AGGRESSIVE
543@end table
544
5ee03c86 545@item -ec bit_mask
4c5f7207 546Set error concealment to @var{bit_mask}. @var{bit_mask} is a bit mask of
5ee03c86 547the following values:
18bff752
FB
548@table @samp
549@item 1
4c5f7207 550FF_EC_GUESS_MVS (default = enabled)
18bff752 551@item 2
4c5f7207 552FF_EC_DEBLOCK (default = enabled)
18bff752
FB
553@end table
554
555@item -bf frames
4c5f7207 556Use 'frames' B-frames (supported for MPEG-1, MPEG-2 and MPEG-4).
18bff752
FB
557@item -mbd mode
558macroblock decision
559@table @samp
560@item 0
4c5f7207 561FF_MB_DECISION_SIMPLE: Use mb_cmp (cannot change it yet in FFmpeg).
18bff752 562@item 1
4c5f7207 563FF_MB_DECISION_BITS: Choose the one which needs the fewest bits.
18bff752 564@item 2
019c8838 565FF_MB_DECISION_RD: rate distortion
18bff752
FB
566@end table
567
568@item -4mv
4c5f7207 569Use four motion vector by macroblock (MPEG-4 only).
18bff752 570@item -part
4c5f7207 571Use data partitioning (MPEG-4 only).
18bff752 572@item -bug param
4c5f7207 573Work around encoder bugs that are not auto-detected.
18bff752 574@item -strict strictness
4c5f7207 575How strictly to follow the standards.
5ee03c86 576@item -aic
4c5f7207 577Enable Advanced intra coding (h263+).
5ee03c86 578@item -umv
4c5f7207 579Enable Unlimited Motion Vector (h263+)
18bff752
FB
580
581@item -deinterlace
4c5f7207 582Deinterlace pictures.
3841e813 583@item -ilme
4c5f7207
DB
584Force interlacing support in encoder (MPEG-2 and MPEG-4 only).
585Use this option if your input file is interlaced and you want
586to keep the interlaced format for minimum losses.
587The alternative is to deinterlace the input stream with
588@option{-deinterlace}, but deinterlacing introduces losses.
18bff752 589@item -psnr
4c5f7207 590Calculate PSNR of compressed frames.
18bff752 591@item -vstats
4c5f7207 592Dump video coding statistics to @file{vstats_HHMMSS.log}.
b60d1379
SS
593@item -vstats_file file
594Dump video coding statistics to @var{file}.
18bff752 595@item -vhook module
4c5f7207 596Insert video processing @var{module}. @var{module} contains the module
18bff752 597name and its parameters separated by spaces.
4386f941
DB
598@item -top n
599top=1/bottom=0/auto=-1 field first
600@item -dc precision
601Intra_dc_precision.
602@item -vtag fourcc/tag
603Force video tag/fourcc.
604@item -qphist
605Show QP histogram.
606@item -vbsf bitstream filter
607Bitstream filters available are "dump_extra", "remove_extra", "noise".
18bff752
FB
608@end table
609
610@section Audio Options
611
612@table @option
4386f941
DB
613@item -aframes number
614Set the number of audio frames to record.
115329f1 615@item -ar freq
4c5f7207 616Set the audio sampling frequency (default = 44100 Hz).
115329f1 617@item -ab bitrate
5438308f 618Set the audio bitrate in bit/s (default = 64k).
18bff752 619@item -ac channels
4c5f7207 620Set the number of audio channels (default = 1).
5ee03c86 621@item -an
4c5f7207 622Disable audio recording.
5ee03c86 623@item -acodec codec
4c5f7207
DB
624Force audio codec to @var{codec}. Use the @code{copy} special value to
625specify that the raw codec data must be copied as is.
de62a89d 626@item -newaudio
18fd519f
DB
627Add a new audio track to the output file. If you want to specify parameters,
628do so before @code{-newaudio} (@code{-acodec}, @code{-ab}, etc..).
de62a89d 629
18fd519f
DB
630Mapping will be done automatically, if the number of output streams is equal to
631the number of input streams, else it will pick the first one that matches. You
de62a89d
VP
632can override the mapping using @code{-map} as usual.
633
634Example:
635@example
5438308f 636ffmpeg -i file.mpg -vcodec copy -acodec ac3 -ab 384k test.mpg -acodec mp2 -ab 192k -newaudio
de62a89d 637@end example
4386f941
DB
638@item -alang code
639Set the ISO 639 language code (3 letters) of the current audio stream.
640@end table
641
642@section Advanced Audio options:
643
644@table @option
645@item -atag fourcc/tag
646Force audio tag/fourcc.
647@item -absf bitstream filter
648Bitstream filters available are "dump_extra", "remove_extra", "noise", "mp3comp", "mp3decomp".
649@end table
650
651@section Subtitle options:
652
653@table @option
654@item -scodec codec
655Force subtitle codec ('copy' to copy stream).
656@item -newsubtitle
657Add a new subtitle stream to the current output stream.
658@item -slang code
659Set the ISO 639 language code (3 letters) of the current subtitle stream.
18bff752
FB
660@end table
661
662@section Audio/Video grab options
663
664@table @option
18bff752 665@item -vc channel
4c5f7207 666Set video grab channel (DV1394 only).
18bff752 667@item -tvstd standard
4c5f7207 668Set television standard (NTSC, PAL (SECAM)).
cc58300e
RP
669@item -isync
670Synchronize read on input.
18bff752
FB
671@end table
672
673@section Advanced options
674
675@table @option
e645a733
BL
676@item -map input stream id[:input stream id]
677Set stream mapping from input streams to output streams.
678Just enumerate the input streams in the order you want them in the output.
679[input stream id] sets the (input) stream to sync against.
4386f941
DB
680@item -map_meta_data outfile:infile
681Set meta data information of outfile from infile.
18bff752 682@item -debug
4c5f7207 683Print specific debug info.
115329f1 684@item -benchmark
4c5f7207 685Add timings for benchmarking.
4386f941 686@item -dump
4c5f7207 687Dump each input packet.
4386f941
DB
688@item -hex
689When dumping packets, also dump the payload.
18bff752 690@item -bitexact
4c5f7207 691Only use bit exact algorithms (for codec testing).
18bff752 692@item -ps size
4c5f7207 693Set packet size in bits.
5ee03c86 694@item -re
4c5f7207 695Read input at native frame rate. Mainly used to simulate a grab device.
4386f941 696@item -loop_input
4c5f7207
DB
697Loop over the input stream. Currently it works only for image
698streams. This option is used for automatic FFserver testing.
8108551a 699@item -loop_output number_of_times
019c8838 700Repeatedly loop output for formats that support looping such as animated GIF
4c5f7207 701(0 will loop the output infinitely).
4386f941
DB
702@item -threads count
703Thread count.
c52e13f1 704@item -vsync parameter
29c9183c
DB
705Video sync method. Video will be stretched/squeezed to match the timestamps,
706it is done by duplicating and dropping frames. With -map you can select from
707which stream the timestamps should be taken. You can leave either video or
c52e13f1
BL
708audio unchanged and sync the remaining stream(s) to the unchanged one.
709@item -async samples_per_second
29c9183c 710Audio sync method. "Stretches/squeezes" the audio stream to match the timestamps,
c52e13f1
BL
711the parameter is the maximum samples per second by which the audio is changed.
712-async 1 is a special case where only the start of the audio stream is corrected
713without any later correction.
43399718
VP
714@item -copyts
715Copy timestamps from input to output.
716@item -shortest
717Finish encoding when the shortest input stream ends.
718@item -dts_delta_threshold
719Timestamp discontinuity delta threshold.
720@item -muxdelay seconds
721Set the maximum demux-decode delay.
722@item -muxpreload seconds
723Set the initial demux-decode delay.
9181577c 724@end table
18bff752
FB
725
726@node FFmpeg formula evaluator
727@section FFmpeg formula evaluator
728
729When evaluating a rate control string, FFmpeg uses an internal formula
115329f1 730evaluator.
18bff752
FB
731
732The following binary operators are available: @code{+}, @code{-},
733@code{*}, @code{/}, @code{^}.
734
735The following unary operators are available: @code{+}, @code{-},
736@code{(...)}.
737
738The following functions are available:
739@table @var
740@item sinh(x)
741@item cosh(x)
742@item tanh(x)
743@item sin(x)
744@item cos(x)
745@item tan(x)
746@item exp(x)
747@item log(x)
748@item squish(x)
749@item gauss(x)
750@item abs(x)
751@item max(x, y)
752@item min(x, y)
753@item gt(x, y)
754@item lt(x, y)
755@item eq(x, y)
756@item bits2qp(bits)
757@item qp2bits(qp)
758@end table
759
760The following constants are available:
761@table @var
762@item PI
763@item E
764@item iTex
765@item pTex
766@item tex
767@item mv
768@item fCode
769@item iCount
770@item mcVar
771@item var
772@item isI
773@item isP
774@item isB
775@item avgQP
776@item qComp
777@item avgIITex
778@item avgPITex
779@item avgPPTex
780@item avgBPTex
781@item avgTex
782@end table
783
e99c4e10
FB
784@c man end
785
786@ignore
787
788@setfilename ffmpeg
789@settitle FFmpeg video converter
790
791@c man begin SEEALSO
019c8838 792ffserver(1), ffplay(1) and the HTML documentation of @file{ffmpeg}.
e99c4e10
FB
793@c man end
794
795@c man begin AUTHOR
796Fabrice Bellard
797@c man end
798
799@end ignore
9181577c
FB
800
801@section Protocols
802
4c5f7207
DB
803The filename can be @file{-} to read from standard input or to write
804to standard output.
9181577c 805
4c5f7207 806FFmpeg also handles many protocols specified with an URL syntax.
9181577c 807
4c5f7207 808Use 'ffmpeg -formats' to see a list of the supported protocols.
9181577c 809
e99c4e10 810The protocol @code{http:} is currently used only to communicate with
4c5f7207 811FFserver (see the FFserver documentation). When FFmpeg will be a
e99c4e10 812video player it will also be used for streaming :-)
9181577c
FB
813
814@chapter Tips
815
816@itemize
4c5f7207
DB
817@item For streaming at very low bitrate application, use a low frame rate
818and a small GOP size. This is especially true for RealVideo where
e99c4e10
FB
819the Linux player does not seem to be very fast, so it can miss
820frames. An example is:
9181577c
FB
821
822@example
3c0ba870 823ffmpeg -g 3 -r 3 -t 10 -b 50k -s qcif -f rv10 /tmp/b.rm
9181577c
FB
824@end example
825
826@item The parameter 'q' which is displayed while encoding is the current
4c5f7207
DB
827quantizer. The value 1 indicates that a very good quality could
828be achieved. The value 31 indicates the worst quality. If q=31 appears
e99c4e10 829too often, it means that the encoder cannot compress enough to meet
4c5f7207 830your bitrate. You must either increase the bitrate, decrease the
e99c4e10 831frame rate or decrease the frame size.
9181577c
FB
832
833@item If your computer is not fast enough, you can speed up the
e99c4e10
FB
834compression at the expense of the compression ratio. You can use
835'-me zero' to speed up motion estimation, and '-intra' to disable
4c5f7207 836motion estimation completely (you have only I-frames, which means it
e99c4e10 837is about as good as JPEG compression).
9181577c 838
4c5f7207 839@item To have very low audio bitrates, reduce the sampling frequency
019c8838 840(down to 22050 kHz for MPEG audio, 22050 or 11025 for AC3).
9181577c
FB
841
842@item To have a constant quality (but a variable bitrate), use the option
e99c4e10
FB
843'-qscale n' when 'n' is between 1 (excellent quality) and 31 (worst
844quality).
9181577c
FB
845
846@item When converting video files, you can use the '-sameq' option which
4c5f7207
DB
847uses the same quality factor in the encoder as in the decoder.
848It allows almost lossless encoding.
9181577c
FB
849
850@end itemize
851
47404f9f
DB
852
853@chapter external libraries
854
855FFmpeg can be hooked up with a number of external libraries to add support
7bb93206
DB
856for more formats. None of them are used by default, their use has to be
857explicitly requested by passing the appropriate flags to @file{./configure}.
47404f9f
DB
858
859@section AMR
860
861AMR comes in two different flavors, WB and NB. FFmpeg can make use of the
73508bc6
DB
862AMR WB (floating-point mode) and the AMR NB (floating-point mode) reference
863decoders and encoders.
47404f9f 864
73508bc6 865Go to @url{http://www.penguin.cz/~utx/amr} and follow the instructions for
197b07f3
DB
866installing the libraries. Then pass @code{--enable-libamr-nb} and/or
867@code{--enable-libamr-wb} to configure to enable the libraries.
47404f9f
DB
868
869
9181577c
FB
870@chapter Supported File Formats and Codecs
871
872You can use the @code{-formats} option to have an exhaustive list.
873
874@section File Formats
875
6bf40f39 876FFmpeg supports the following file formats through the @code{libavformat}
0699d2fe 877library:
9181577c 878
3fc9e78f 879@multitable @columnfractions .4 .1 .1 .4
9181577c
FB
880@item Supported File Format @tab Encoding @tab Decoding @tab Comments
881@item MPEG audio @tab X @tab X
4c5f7207 882@item MPEG-1 systems @tab X @tab X
9181577c 883@tab muxed audio and video
4c5f7207 884@item MPEG-2 PS @tab X @tab X
9181577c 885@tab also known as @code{VOB} file
4c5f7207 886@item MPEG-2 TS @tab @tab X
9181577c 887@tab also known as DVB Transport Stream
115329f1
DB
888@item ASF@tab X @tab X
889@item AVI@tab X @tab X
890@item WAV@tab X @tab X
9181577c 891@item Macromedia Flash@tab X @tab X
4c5f7207 892@tab Only embedded audio is decoded.
2eb5d024
FB
893@item FLV @tab X @tab X
894@tab Macromedia Flash video files
115329f1
DB
895@item Real Audio and Video @tab X @tab X
896@item Raw AC3 @tab X @tab X
897@item Raw MJPEG @tab X @tab X
898@item Raw MPEG video @tab X @tab X
899@item Raw PCM8/16 bits, mulaw/Alaw@tab X @tab X
900@item Raw CRI ADX audio @tab X @tab X
901@item Raw Shorten audio @tab @tab X
902@item SUN AU format @tab X @tab X
7fe4c823 903@item NUT @tab X @tab X @tab NUT Open Container Format
115329f1 904@item QuickTime @tab X @tab X
4c5f7207
DB
905@item MPEG-4 @tab X @tab X
906@tab MPEG-4 is a variant of QuickTime.
115329f1 907@item Raw MPEG4 video @tab X @tab X
4fa1c4fa 908@item DV @tab X @tab X
701b603d 909@item 4xm @tab @tab X
4c5f7207 910@tab 4X Technologies format, used in some games.
4d3b1f8d 911@item Playstation STR @tab @tab X
13dec857 912@item Id RoQ @tab X @tab X
4c5f7207 913@tab Used in Quake III, Jedi Knight 2, other computer games.
4d3b1f8d 914@item Interplay MVE @tab @tab X
4c5f7207 915@tab Format used in various Interplay computer games.
b17e9c99 916@item WC3 Movie @tab @tab X
4c5f7207 917@tab Multimedia format used in Origin's Wing Commander III computer game.
2fdf638b 918@item Sega FILM/CPK @tab @tab X
4c5f7207 919@tab Used in many Sega Saturn console games.
2fdf638b 920@item Westwood Studios VQA/AUD @tab @tab X
4c5f7207 921@tab Multimedia formats used in Westwood Studios games.
4120a53a 922@item Id Cinematic (.cin) @tab @tab X
4c5f7207 923@tab Used in Quake II.
42cad81a
MM
924@item FLIC format @tab @tab X
925@tab .fli/.flc files
da00f30e 926@item Sierra VMD @tab @tab X
4c5f7207 927@tab Used in Sierra CD-ROM games.
d08d7142 928@item Sierra Online @tab @tab X
4c5f7207 929@tab .sol files used in Sierra Online games.
38088adf 930@item Matroska @tab @tab X
ad81a9fe 931@item Electronic Arts Multimedia @tab @tab X
4c5f7207 932@tab Used in various EA games; files have extensions like WVE and UV2.
353147ed 933@item Nullsoft Video (NSV) format @tab @tab X
4accd1fd 934@item ADTS AAC audio @tab X @tab X
ea395e8c 935@item Creative VOC @tab X @tab X @tab Created for the Sound Blaster Pro.
4e114829
MM
936@item American Laser Games MM @tab @tab X
937@tab Multimedia format used in games like Mad Dog McCree
26376701
MM
938@item AVS @tab @tab X
939@tab Multimedia format used by the Creature Shock game.
348efc18
KS
940@item Smacker @tab @tab X
941@tab Multimedia format used by many games.
d7a3a783
BC
942@item GXF @tab X @tab X
943@tab General eXchange Format SMPTE 360M, used by Thomson Grass Valley playout servers.
dc56e0de
BC
944@item CIN @tab @tab X
945@tab Multimedia format used by Delphine Software games.
f3239539
BC
946@item MXF @tab @tab X
947@tab Material eXchange Format SMPTE 377M, used by D-Cinema, broadcast industry.
29f86228
BC
948@item SEQ @tab @tab X
949@tab Tiertex .seq files used in the DOS CDROM version of the game Flashback.
33a0dd37
KS
950@item DXA @tab @tab X
951@tab This format is used in non-Windows version of Feeble Files game and
952different game cutscenes repacked for use with ScummVM.
efb0c399 953@item THP @tab @tab X
d1e0d21f 954@tab Used on the Nintendo GameCube.
9a0ddd09
AH
955@item C93 @tab @tab X
956@tab Used in the game Cyberia from Interplay.
1e6c6759
NT
957@item Bethsoft VID @tab @tab X
958@tab Used in some games from Bethesda Softworks.
8e952e4d
AH
959@item CRYO APC @tab @tab X
960@tab Audio format used in some games by CRYO Interactive Entertainment.
353147ed 961@end multitable
9181577c 962
4c5f7207 963@code{X} means that encoding (resp. decoding) is supported.
9181577c 964
0699d2fe
FB
965@section Image Formats
966
967FFmpeg can read and write images for each frame of a video sequence. The
968following image formats are supported:
969
3fc9e78f 970@multitable @columnfractions .4 .1 .1 .4
0699d2fe 971@item Supported Image Format @tab Encoding @tab Decoding @tab Comments
115329f1 972@item PGM, PPM @tab X @tab X
4c5f7207 973@item PAM @tab X @tab X @tab PAM is a PNM extension with alpha support.
2eb5d024 974@item PGMYUV @tab X @tab X @tab PGM with U and V components in YUV 4:2:0
4c5f7207
DB
975@item JPEG @tab X @tab X @tab Progressive JPEG is not supported.
976@item .Y.U.V @tab X @tab X @tab one raw file per component
977@item animated GIF @tab X @tab X @tab Only uncompressed GIFs are generated.
978@item PNG @tab X @tab X @tab 2 bit and 4 bit/pixel not supported yet.
3689cf16 979@item Targa @tab @tab X @tab Targa (.TGA) image format.
716222db 980@item TIFF @tab X @tab X @tab YUV, JPEG and some extension is not supported yet.
6a91ec51 981@item SGI @tab X @tab X @tab SGI RGB image format
d58bbf81 982@item PTX @tab @tab X @tab V.Flash PTX format
0699d2fe
FB
983@end multitable
984
4c5f7207 985@code{X} means that encoding (resp. decoding) is supported.
0699d2fe 986
9181577c
FB
987@section Video Codecs
988
3fc9e78f 989@multitable @columnfractions .4 .1 .1 .4
9181577c 990@item Supported Codec @tab Encoding @tab Decoding @tab Comments
4c5f7207
DB
991@item MPEG-1 video @tab X @tab X
992@item MPEG-2 video @tab X @tab X
2bc5da7b 993@item MPEG-4 @tab X @tab X
9181577c
FB
994@item MSMPEG4 V1 @tab X @tab X
995@item MSMPEG4 V2 @tab X @tab X
2bc5da7b 996@item MSMPEG4 V3 @tab X @tab X
9181577c 997@item WMV7 @tab X @tab X
4c5f7207 998@item WMV8 @tab X @tab X @tab not completely working
17a21f3c
DB
999@item WMV9 @tab @tab X @tab not completely working
1000@item VC1 @tab @tab X
b06b45c4 1001@item H.261 @tab X @tab X
4c5f7207 1002@item H.263(+) @tab X @tab X @tab also known as RealVideo 1.0
b06b45c4 1003@item H.264 @tab @tab X
e839a994
DB
1004@item RealVideo 1.0 @tab X @tab X
1005@item RealVideo 2.0 @tab X @tab X
115329f1 1006@item MJPEG @tab X @tab X
4c5f7207 1007@item lossless MJPEG @tab X @tab X
26d6d032 1008@item JPEG-LS @tab X @tab X @tab fourcc: MJLS, lossless and near-lossless is supported
d6896c49
AB
1009@item Apple MJPEG-B @tab @tab X
1010@item Sunplus MJPEG @tab @tab X @tab fourcc: SP5X
115329f1 1011@item DV @tab X @tab X
4c5f7207
DB
1012@item HuffYUV @tab X @tab X
1013@item FFmpeg Video 1 @tab X @tab X @tab experimental lossless codec (fourcc: FFV1)
1014@item FFmpeg Snow @tab X @tab X @tab experimental wavelet codec (fourcc: SNOW)
701b603d 1015@item Asus v1 @tab X @tab X @tab fourcc: ASV1
4d3b1f8d 1016@item Asus v2 @tab X @tab X @tab fourcc: ASV2
701b603d 1017@item Creative YUV @tab @tab X @tab fourcc: CYUV
d2bfadc0 1018@item Sorenson Video 1 @tab X @tab X @tab fourcc: SVQ1
701b603d
MM
1019@item Sorenson Video 3 @tab @tab X @tab fourcc: SVQ3
1020@item On2 VP3 @tab @tab X @tab still experimental
5ce117c3 1021@item On2 VP5 @tab @tab X @tab fourcc: VP50
9110a0e3 1022@item On2 VP6 @tab @tab X @tab fourcc: VP60,VP61,VP62
150d2772 1023@item Theora @tab X @tab X @tab still experimental
cdb2c1ca 1024@item Intel Indeo 3 @tab @tab X
9303d49c 1025@item FLV @tab X @tab X @tab Sorenson H.263 used in Flash
15419468 1026@item Flash Screen Video @tab X @tab X @tab fourcc: FSV1
4d3b1f8d 1027@item ATI VCR1 @tab @tab X @tab fourcc: VCR1
7fe4c823 1028@item ATI VCR2 @tab @tab X @tab fourcc: VCR2
4d3b1f8d 1029@item Cirrus Logic AccuPak @tab @tab X @tab fourcc: CLJR
4c5f7207 1030@item 4X Video @tab @tab X @tab Used in certain computer games.
115329f1 1031@item Sony Playstation MDEC @tab @tab X
03e3e765 1032@item Id RoQ @tab X @tab X @tab Used in Quake III, Jedi Knight 2, other computer games.
4c5f7207
DB
1033@item Xan/WC3 @tab @tab X @tab Used in Wing Commander III .MVE files.
1034@item Interplay Video @tab @tab X @tab Used in Interplay .MVE files.
d3b7406c 1035@item Apple Animation @tab X @tab X @tab fourcc: 'rle '
42cad81a 1036@item Apple Graphics @tab @tab X @tab fourcc: 'smc '
2fdf638b 1037@item Apple Video @tab @tab X @tab fourcc: rpza
d08d7142 1038@item Apple QuickDraw @tab @tab X @tab fourcc: qdrw
2fdf638b
MM
1039@item Cinepak @tab @tab X
1040@item Microsoft RLE @tab @tab X
1041@item Microsoft Video-1 @tab @tab X
4120a53a 1042@item Westwood VQA @tab @tab X
4c5f7207 1043@item Id Cinematic Video @tab @tab X @tab Used in Quake II.
1dc1ed99 1044@item Planar RGB @tab @tab X @tab fourcc: 8BPS
42cad81a 1045@item FLIC video @tab @tab X
9a4117d5 1046@item Duck TrueMotion v1 @tab @tab X @tab fourcc: DUCK
dce76c20 1047@item Duck TrueMotion v2 @tab @tab X @tab fourcc: TM20
4c5f7207 1048@item VMD Video @tab @tab X @tab Used in Sierra VMD files.
a273bbfb
RT
1049@item MSZH @tab @tab X @tab Part of LCL
1050@item ZLIB @tab X @tab X @tab Part of LCL, encoder experimental
9d53d58e 1051@item TechSmith Camtasia @tab @tab X @tab fourcc: TSCC
d0a0bbd2 1052@item IBM Ultimotion @tab @tab X @tab fourcc: ULTI
ab711b3c 1053@item Miro VideoXL @tab @tab X @tab fourcc: VIXL
acfd8f0f 1054@item QPEG @tab @tab X @tab fourccs: QPEG, Q1.0, Q1.1
115329f1
DB
1055@item LOCO @tab @tab X @tab
1056@item Winnov WNV1 @tab @tab X @tab
589f8220 1057@item Autodesk Animator Studio Codec @tab @tab X @tab fourcc: AASC
115329f1 1058@item Fraps FPS1 @tab @tab X @tab
2b6c1d80 1059@item CamStudio @tab @tab X @tab fourcc: CSCD
4e114829 1060@item American Laser Games Video @tab @tab X @tab Used in games like Mad Dog McCree
f48d6e1b 1061@item ZMBV @tab X @tab X @tab Encoder works only on PAL8
26376701 1062@item AVS Video @tab @tab X @tab Video encoding used by the Creature Shock game.
348efc18 1063@item Smacker Video @tab @tab X @tab Video encoding used in Smacker.
dfca23e3 1064@item RTjpeg @tab @tab X @tab Video encoding used in NuppelVideo files.
fd7b1991 1065@item KMVC @tab @tab X @tab Codec used in Worms games.
eb57c889 1066@item VMware Video @tab @tab X @tab Codec used in videos captured by VMware.
dc56e0de 1067@item Cin Video @tab @tab X @tab Codec used in Delphine Software games.
29f86228 1068@item Tiertex Seq Video @tab @tab X @tab Codec used in DOS CDROM FlashBack game.
33a0dd37 1069@item DXA Video @tab @tab X @tab Codec originally used in Feeble Files game.
52b6bad2 1070@item AVID DNxHD @tab @tab X @tab aka SMPTE VC3
9a0ddd09 1071@item C93 Video @tab @tab X @tab Codec used in Cyberia game.
8845202e 1072@item THP @tab @tab X @tab Used on the Nintendo GameCube.
1e6c6759 1073@item Bethsoft VID @tab @tab X @tab Used in some games from Bethesda Softworks.
12b6d7c0 1074@item Renderware TXD @tab @tab X @tab Texture dictionaries used by the Renderware Engine.
9181577c
FB
1075@end multitable
1076
4c5f7207 1077@code{X} means that encoding (resp. decoding) is supported.
9181577c
FB
1078
1079@section Audio Codecs
1080
1081@multitable @columnfractions .4 .1 .1 .1 .7
1082@item Supported Codec @tab Encoding @tab Decoding @tab Comments
115329f1 1083@item MPEG audio layer 2 @tab IX @tab IX
9181577c 1084@item MPEG audio layer 1/3 @tab IX @tab IX
4c5f7207 1085@tab MP3 encoding is supported through the external library LAME.
37776c3b 1086@item AC3 @tab IX @tab IX
4c5f7207 1087@tab liba52 is used internally for decoding.
34d7008d 1088@item Vorbis @tab X @tab X
74882049 1089@item WMA V1/V2 @tab X @tab X
f6fa7a6c 1090@item AAC @tab X @tab X
4c5f7207 1091@tab Supported through the external library libfaac/libfaad.
d4c3c5a6 1092@item Microsoft ADPCM @tab X @tab X
4d3b1f8d
MM
1093@item MS IMA ADPCM @tab X @tab X
1094@item QT IMA ADPCM @tab @tab X
1095@item 4X IMA ADPCM @tab @tab X
d4e437df 1096@item G.726 ADPCM @tab X @tab X
b17e9c99 1097@item Duck DK3 IMA ADPCM @tab @tab X
4c5f7207 1098@tab Used in some Sega Saturn console games.
b17e9c99 1099@item Duck DK4 IMA ADPCM @tab @tab X
4c5f7207 1100@tab Used in some Sega Saturn console games.
2fdf638b 1101@item Westwood Studios IMA ADPCM @tab @tab X
4c5f7207 1102@tab Used in Westwood Studios games like Command and Conquer.
7d8379f2 1103@item SMJPEG IMA ADPCM @tab @tab X
4c5f7207 1104@tab Used in certain Loki game ports.
42cad81a
MM
1105@item CD-ROM XA ADPCM @tab @tab X
1106@item CRI ADX ADPCM @tab X @tab X
4c5f7207 1107@tab Used in Sega Dreamcast games.
7d8379f2 1108@item Electronic Arts ADPCM @tab @tab X
4c5f7207 1109@tab Used in various EA titles.
b3bfb299 1110@item Creative ADPCM @tab @tab X
2433f24f 1111@tab 16 -> 4, 8 -> 4, 8 -> 3, 8 -> 2
8845202e
DB
1112@item THP ADPCM @tab @tab X
1113@tab Used on the Nintendo GameCube.
2eb5d024
FB
1114@item RA144 @tab @tab X
1115@tab Real 14400 bit/s codec
1116@item RA288 @tab @tab X
1117@tab Real 28800 bit/s codec
37776c3b 1118@item RADnet @tab X @tab IX
4c5f7207 1119@tab Real low bitrate AC3 codec, liba52 is used for decoding.
2eb5d024 1120@item AMR-NB @tab X @tab X
4c5f7207 1121@tab Supported through an external library.
d663a1fd 1122@item AMR-WB @tab X @tab X
4c5f7207 1123@tab Supported through an external library.
2eb5d024 1124@item DV audio @tab @tab X
b09432ad 1125@item Id RoQ DPCM @tab X @tab X
4c5f7207 1126@tab Used in Quake III, Jedi Knight 2, other computer games.
4d3b1f8d 1127@item Interplay MVE DPCM @tab @tab X
4c5f7207 1128@tab Used in various Interplay computer games.
b17e9c99 1129@item Xan DPCM @tab @tab X
4c5f7207 1130@tab Used in Origin's Wing Commander IV AVI files.
d08d7142 1131@item Sierra Online DPCM @tab @tab X
4c5f7207 1132@tab Used in Sierra Online game audio files.
d6896c49
AB
1133@item Apple MACE 3 @tab @tab X
1134@item Apple MACE 6 @tab @tab X
bfd9a00f 1135@item FLAC lossless audio @tab X @tab X
13dfd2b9 1136@item Shorten lossless audio @tab @tab X
f770ee03
MM
1137@item Apple lossless audio @tab @tab X
1138@tab QuickTime fourcc 'alac'
33a4d8b1 1139@item FFmpeg Sonic @tab X @tab X
4c5f7207 1140@tab experimental lossy/lossless codec
d9b1c197
RT
1141@item Qdesign QDM2 @tab @tab X
1142@tab there are still some distortions
440e7988
RT
1143@item Real COOK @tab @tab X
1144@tab All versions except 5.1 are supported
e839a994 1145@item DSP Group TrueSpeech @tab @tab X
3dc411c0 1146@item True Audio (TTA) @tab @tab X
348efc18 1147@item Smacker Audio @tab @tab X
730581f3 1148@item WavPack Audio @tab @tab X
dc56e0de
BC
1149@item Cin Audio @tab @tab X
1150@tab Codec used in Delphine Software games.
84ed36da 1151@item Intel Music Coder @tab @tab X
185c7b6b
KS
1152@item Musepack @tab @tab X
1153@tab Only SV7 is supported
01ca9ac3 1154@item DT$ Coherent Audio @tab @tab X
10e26bc7 1155@item ATRAC 3 @tab @tab X
9181577c
FB
1156@end multitable
1157
4c5f7207 1158@code{X} means that encoding (resp. decoding) is supported.
9181577c 1159
4c5f7207
DB
1160@code{I} means that an integer-only version is available, too (ensures high
1161performance on systems without hardware floating point support).
9181577c 1162
47d944d2
FB
1163@chapter Platform Specific information
1164
47d944d2
FB
1165@section BSD
1166
21d1cb12
DB
1167BSD make will not build FFmpeg, you need to install and use GNU Make
1168(@file{gmake}).
1169
47d944d2
FB
1170@section Windows
1171
e2ef53fc
DB
1172To get help and instructions for using FFmpeg under Windows, check out
1173the FFmpeg Windows Help Forum at
1174@url{http://arrozcru.no-ip.org/ffmpeg/}.
1175
b030b284
FB
1176@subsection Native Windows compilation
1177
1178@itemize
1179@item Install the current versions of MSYS and MinGW from
1180@url{http://www.mingw.org/}. You can find detailed installation
1181instructions in the download section and the FAQ.
1182
f2d64c19
AB
1183NOTE: Use at least bash 3.1. Older versions are known to be failing on the
1184configure script.
1185
4c5f7207 1186@item If you want to test the FFplay, also download
50f52fcd
FB
1187the MinGW development library of SDL 1.2.x
1188(@file{SDL-devel-1.2.x-mingw32.tar.gz}) from
4c5f7207 1189@url{http://www.libsdl.org}. Unpack it in a temporary directory, and
50f52fcd 1190unpack the archive @file{i386-mingw32msvc.tar.gz} in the MinGW tool
988a9f9e
FB
1191directory. Edit the @file{sdl-config} script so that it gives the
1192correct SDL directory when invoked.
50f52fcd 1193
c74a8fe6
RP
1194@item If you want to use vhooks, you must have a POSIX compliant libdl in your
1195MinGW system. Get dlfcn-win32 from @url{http://code.google.com/p/dlfcn-win32}.
1196
e926e391 1197@item Extract the current version of FFmpeg.
115329f1 1198
b030b284
FB
1199@item Start the MSYS shell (file @file{msys.bat}).
1200
4c5f7207
DB
1201@item Change to the FFmpeg directory and follow
1202 the instructions of how to compile FFmpeg (file
50f52fcd
FB
1203@file{INSTALL}). Usually, launching @file{./configure} and @file{make}
1204suffices. If you have problems using SDL, verify that
1205@file{sdl-config} can be launched from the MSYS command line.
1206
4c5f7207 1207@item You can install FFmpeg in @file{Program Files/FFmpeg} by typing
ce10ff8e 1208@file{make install}. Do not forget to copy @file{SDL.dll} to the place
4c5f7207 1209you launch @file{ffplay} from.
50f52fcd 1210
b030b284
FB
1211@end itemize
1212
115329f1 1213Notes:
988a9f9e 1214@itemize
50f52fcd 1215
988a9f9e
FB
1216@item The target @file{make wininstaller} can be used to create a
1217Nullsoft based Windows installer for FFmpeg and FFplay. @file{SDL.dll}
4c5f7207 1218must be copied to the FFmpeg directory in order to build the
988a9f9e
FB
1219installer.
1220
4c5f7207 1221@item By using @code{./configure --enable-shared} when configuring FFmpeg,
988a9f9e
FB
1222you can build @file{avcodec.dll} and @file{avformat.dll}. With
1223@code{make install} you install the FFmpeg DLLs and the associated
115329f1 1224headers in @file{Program Files/FFmpeg}.
988a9f9e 1225
4c5f7207
DB
1226@item Visual C++ compatibility: If you used @code{./configure --enable-shared}
1227when configuring FFmpeg, FFmpeg tries to use the Microsoft Visual
988a9f9e 1228C++ @code{lib} tool to build @code{avcodec.lib} and
4c5f7207 1229@code{avformat.lib}. With these libraries you can link your Visual C++
be0efc0c 1230code directly with the FFmpeg DLLs (see below).
988a9f9e
FB
1231
1232@end itemize
b030b284 1233
be0efc0c
MB
1234@subsection Visual C++ compatibility
1235
1236FFmpeg will not compile under Visual C++ -- and it has too many
1237dependencies on the GCC compiler to make a port viable. However,
1238if you want to use the FFmpeg libraries in your own applications,
1239you can still compile those applications using Visual C++. An
1240important restriction to this is that you have to use the
1241dynamically linked versions of the FFmpeg libraries (i.e. the
1242DLLs), and you have to make sure that Visual-C++-compatible
1243import libraries are created during the FFmpeg build process.
1244
1245This description of how to use the FFmpeg libraries with Visual C++ is
1246based on Visual C++ 2005 Express Edition Beta 2. If you have a different
1247version, you might have to modify the procedures slightly.
1248
1249Here are the step-by-step instructions for building the FFmpeg libraries
1250so they can be used with Visual C++:
1251
1252@enumerate
1253
ce10ff8e 1254@item Install Visual C++ (if you have not done so already).
be0efc0c
MB
1255
1256@item Install MinGW and MSYS as described above.
1257
1258@item Add a call to @file{vcvars32.bat} (which sets up the environment
1259variables for the Visual C++ tools) as the first line of
1260@file{msys.bat}. The standard location for @file{vcvars32.bat} is
1261@file{C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat},
1262and the standard location for @file{msys.bat} is
1263@file{C:\msys\1.0\msys.bat}. If this corresponds to your setup, add the
1264following line as the first line of @file{msys.bat}:
1265
1266@code{call "C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat"}
1267
1268@item Start the MSYS shell (file @file{msys.bat}) and type @code{link.exe}.
1269If you get a help message with the command line options of @code{link.exe},
1270this means your environment variables are set up correctly, the
1271Microsoft linker is on the path and will be used by FFmpeg to
1272create Visual-C++-compatible import libraries.
1273
e926e391 1274@item Extract the current version of FFmpeg and change to the FFmpeg directory.
be0efc0c
MB
1275
1276@item Type the command
51d8321d 1277@code{./configure --enable-shared --disable-static --enable-memalign-hack}
ce10ff8e 1278to configure and, if that did not produce any errors,
51d8321d 1279type @code{make} to build FFmpeg.
be0efc0c
MB
1280
1281@item The subdirectories @file{libavformat}, @file{libavcodec}, and
1282@file{libavutil} should now contain the files @file{avformat.dll},
1283@file{avformat.lib}, @file{avcodec.dll}, @file{avcodec.lib},
1284@file{avutil.dll}, and @file{avutil.lib}, respectively. Copy the three
1285DLLs to your System32 directory (typically @file{C:\Windows\System32}).
1286
1287@end enumerate
1288
1289And here is how to use these libraries with Visual C++:
1290
1291@enumerate
1292
1293@item Create a new console application ("File / New / Project") and then
1294select "Win32 Console Application". On the appropriate page of the
1295Application Wizard, uncheck the "Precompiled headers" option.
1296
1297@item Write the source code for your application, or, for testing, just
1298copy the code from an existing sample application into the source file
1299that Visual C++ has already created for you. (Note that your source
ce10ff8e
DB
1300filehas to have a @code{.cpp} extension; otherwise, Visual C++ will not
1301compile the FFmpeg headers correctly because in C mode, it does not
be0efc0c
MB
1302recognize the @code{inline} keyword.) For example, you can copy
1303@file{output_example.c} from the FFmpeg distribution (but you will
1304have to make minor modifications so the code will compile under
1305C++, see below).
1306
1307@item Open the "Project / Properties" dialog box. In the "Configuration"
1308combo box, select "All Configurations" so that the changes you make will
1309affect both debug and release builds. In the tree view on the left hand
1310side, select "C/C++ / General", then edit the "Additional Include
1311Directories" setting to contain the complete paths to the
1312@file{libavformat}, @file{libavcodec}, and @file{libavutil}
1313subdirectories of your FFmpeg directory. Note that the directories have
1314to be separated using semicolons. Now select "Linker / General" from the
1315tree view and edit the "Additional Library Directories" setting to
1316contain the same three directories.
1317
1318@item Still in the "Project / Properties" dialog box, select "Linker / Input"
1319from the tree view, then add the files @file{avformat.lib},
1320@file{avcodec.lib}, and @file{avutil.lib} to the end of the "Additional
1321Dependencies". Note that the names of the libraries have to be separated
1322using spaces.
1323
765c3440 1324@item Now, select "C/C++ / Code Generation" from the tree view. Select
be0efc0c
MB
1325"Debug" in the "Configuration" combo box. Make sure that "Runtime
1326Library" is set to "Multi-threaded Debug DLL". Then, select "Release" in
1327the "Configuration" combo box and make sure that "Runtime Library" is
1328set to "Multi-threaded DLL".
1329
1330@item Click "OK" to close the "Project / Properties" dialog box and build
1331the application. Hopefully, it should compile and run cleanly. If you
1332used @file{output_example.c} as your sample application, you will get a
1333few compiler errors, but they are easy to fix. The first type of error
ce10ff8e 1334occurs because Visual C++ does not allow an @code{int} to be converted to
be0efc0c
MB
1335an @code{enum} without a cast. To solve the problem, insert the required
1336casts (this error occurs once for a @code{CodecID} and once for a
1337@code{CodecType}). The second type of error occurs because C++ requires
1338the return value of @code{malloc} to be cast to the exact type of the
1339pointer it is being assigned to. Visual C++ will complain that, for
1340example, @code{(void *)} is being assigned to @code{(uint8_t *)} without
1341an explicit cast. So insert an explicit cast in these places to silence
1342the compiler. The third type of error occurs because the @code{snprintf}
1343library function is called @code{_snprintf} under Visual C++. So just
1344add an underscore to fix the problem. With these changes,
1345@file{output_example.c} should compile under Visual C++, and the
1346resulting executable should produce valid video files.
1347
1348@end enumerate
1349
b030b284
FB
1350@subsection Cross compilation for Windows with Linux
1351
1352You must use the MinGW cross compilation tools available at
1353@url{http://www.mingw.org/}.
1354
4c5f7207 1355Then configure FFmpeg with the following options:
b030b284 1356@example
6b74787b 1357./configure --target-os=mingw32 --cross-prefix=i386-mingw32msvc-
b030b284 1358@end example
019c8838 1359(you can change the cross-prefix according to the prefix chosen for the
b030b284
FB
1360MinGW tools).
1361
4c5f7207 1362Then you can easily test FFmpeg with Wine
b030b284
FB
1363(@url{http://www.winehq.com/}).
1364
30aee296
DB
1365@subsection Compilation under Cygwin
1366
1367Cygwin works very much like Unix.
1368
1369Just install your Cygwin with all the "Base" packages, plus the
1370following "Devel" ones:
1371@example
1372binutils, gcc-core, make, subversion
1373@end example
1374
1375Do not install binutils-20060709-1 (they are buggy on shared builds);
1376use binutils-20050610-1 instead.
1377
1378Then run
1379
1380@example
1381./configure --enable-static --disable-shared
1382@end example
1383
1384to make a static build or
1385
1386@example
1387./configure --enable-shared --disable-static
1388@end example
1389
1390to build shared libraries.
1391
1392If you want to build FFmpeg with additional libraries, download Cygwin
1393"Devel" packages for Ogg and Vorbis from any Cygwin packages repository
1394and/or SDL, xvid, faac, faad2 packages from Cygwin Ports,
1395(@url{http://cygwinports.dotsrc.org/}).
1396
1397@subsection Crosscompilation for Windows under Cygwin
1398
ce10ff8e 1399With Cygwin you can create Windows binaries that do not need the cygwin1.dll.
30aee296
DB
1400
1401Just install your Cygwin as explained before, plus these additional
1402"Devel" packages:
1403@example
1404gcc-mingw-core, mingw-runtime, mingw-zlib
1405@end example
1406
1407and add some special flags to your configure invocation.
1408
1409For a static build run
1410@example
6b74787b 1411./configure --target-os=mingw32 --enable-memalign-hack --enable-static --disable-shared --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
30aee296
DB
1412@end example
1413
1414and for a build with shared libraries
1415@example
6b74787b 1416./configure --target-os=mingw32 --enable-memalign-hack --enable-shared --disable-static --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
30aee296
DB
1417@end example
1418
47d944d2
FB
1419@section BeOS
1420
1421The configure script should guess the configuration itself.
1422Networking support is currently not finished.
1423errno issues fixed by Andrew Bachmann.
1424
1425Old stuff:
1426
7dd611c9 1427François Revol - revol at free dot fr - April 2002
47d944d2 1428
115329f1 1429The configure script should guess the configuration itself,
ce10ff8e 1430however I still did not test building on the net_server version of BeOS.
47d944d2 1431
4c5f7207 1432FFserver is broken (needs poll() implementation).
47d944d2 1433
4c5f7207 1434There are still issues with errno codes, which are negative in BeOS, and
115329f1 1435that FFmpeg negates when returning. This ends up turning errors into
47d944d2
FB
1436valid results, then crashes.
1437(To be fixed)
1438
34d7008d 1439@chapter Developers Guide
9181577c
FB
1440
1441@section API
a0b72f90 1442@itemize @bullet
9181577c 1443@item libavcodec is the library containing the codecs (both encoding and
4c5f7207 1444decoding). Look at @file{libavcodec/apiexample.c} to see how to use it.
9181577c 1445
4c5f7207
DB
1446@item libavformat is the library containing the file format handling (mux and
1447demux code for several formats). Look at @file{ffplay.c} to use it in a
a93b9dba
FB
1448player. See @file{output_example.c} to use it to generate audio or video
1449streams.
1450
9181577c
FB
1451@end itemize
1452
1453@section Integrating libavcodec or libavformat in your program
1454
1455You can integrate all the source code of the libraries to link them
1456statically to avoid any version problem. All you need is to provide a
1457'config.mak' and a 'config.h' in the parent directory. See the defines
1458generated by ./configure to understand what is needed.
1459
1460You can use libavcodec or libavformat in your commercial program, but
1461@emph{any patch you make must be published}. The best way to proceed is
4c5f7207 1462to send your patches to the FFmpeg mailing list.
9181577c 1463
80d1c272 1464@node Coding Rules
9181577c
FB
1465@section Coding Rules
1466
4c5f7207 1467FFmpeg is programmed in the ISO C90 language with a few additional
cb6e87c1
FH
1468features from ISO C99, namely:
1469@itemize @bullet
1470@item
1471the @samp{inline} keyword;
1472@item
1473@samp{//} comments;
1474@item
1475designated struct initializers (@samp{struct s x = @{ .i = 17 @};})
1476@item
114afa9c 1477compound literals (@samp{x = (struct s) @{ 17, 23 @};})
cb6e87c1
FH
1478@end itemize
1479
ce10ff8e
DB
1480These features are supported by all compilers we care about, so we will not
1481accept patches to remove their use unless they absolutely do not impair
cb6e87c1
FH
1482clarity and performance.
1483
4c5f7207 1484All code must compile with GCC 2.95 and GCC 3.3. Currently, FFmpeg also
cb6e87c1
FH
1485compiles with several other compilers, such as the Compaq ccc compiler
1486or Sun Studio 9, and we would like to keep it that way unless it would
ce10ff8e 1487be exceedingly involved. To ensure compatibility, please do not use any
4c5f7207 1488additional C99 features or GCC extensions. Especially watch out for:
cb6e87c1
FH
1489@itemize @bullet
1490@item
1491mixing statements and declarations;
1492@item
1493@samp{long long} (use @samp{int64_t} instead);
1494@item
1495@samp{__attribute__} not protected by @samp{#ifdef __GNUC__} or similar;
1496@item
019c8838 1497GCC statement expressions (@samp{(x = (@{ int y = 4; y; @})}).
cb6e87c1 1498@end itemize
9181577c 1499
53862e0f 1500Indent size is 4.
b86e38a0 1501The presentation is the one specified by 'indent -i4 -kr -nut'.
53862e0f
DB
1502The TAB character is forbidden outside of Makefiles as is any
1503form of trailing whitespace. Commits containing either will be
1c1b5a40 1504rejected by the Subversion repository.
9181577c 1505
78a3c678
DB
1506The main priority in FFmpeg is simplicity and small code size in order to
1507minimize the bug count.
9181577c 1508
4c5f7207
DB
1509Comments: Use the JavaDoc/Doxygen
1510format (see examples below) so that code documentation
1511can be generated automatically. All nontrivial functions should have a comment
ce10ff8e 1512above them explaining what the function does, even if it is just one sentence.
4c5f7207 1513All structures and their member variables should be documented, too.
f4888b83
MN
1514@example
1515/**
2185824b
MR
1516 * @@file mpeg.c
1517 * MPEG codec.
1518 * @@author ...
1519 */
f4888b83
MN
1520
1521/**
2185824b
MR
1522 * Summary sentence.
1523 * more text ...
1524 * ...
1525 */
114afa9c 1526typedef struct Foobar@{
2185824b
MR
1527 int var1; /**< var1 description */
1528 int var2; ///< var2 description
1529 /** var3 description */
1530 int var3;
114afa9c 1531@} Foobar;
f4888b83
MN
1532
1533/**
2185824b
MR
1534 * Summary sentence.
1535 * more text ...
1536 * ...
1537 * @@param my_parameter description of my_parameter
1538 * @@return return value description
1539 */
f4888b83
MN
1540int myfunc(int my_parameter)
1541...
1542@end example
9181577c 1543
115329f1 1544fprintf and printf are forbidden in libavformat and libavcodec,
36d9b4e8
MN
1545please use av_log() instead.
1546
7cbf432d
VS
1547Casts should be used only when necessary. Unneeded parentheses
1548should also be avoided if they don't make the code easier to understand.
1549
1c1b5a40 1550@section Development Policy
7a57b90c
MN
1551
1552@enumerate
115329f1 1553@item
0f69ca7f
DB
1554 Contributions should be licensed under the LGPL 2.1, including an
1555 "or any later version" clause, or the MIT license. GPL 2 including
1556 an "or any later version" clause is also acceptable, but LGPL is
1557 preferred.
1558@item
7a57b90c 1559 You must not commit code which breaks FFmpeg! (Meaning unfinished but
4c5f7207 1560 enabled code which breaks compilation or compiles but does not work or
7a57b90c
MN
1561 breaks the regression tests)
1562 You can commit unfinished stuff (for testing etc), but it must be disabled
1563 (#ifdef etc) by default so it does not interfere with other developers'
1564 work.
115329f1 1565@item
ce10ff8e 1566 You do not have to over-test things. If it works for you, and you think it
4c5f7207
DB
1567 should work for others, then commit. If your code has problems
1568 (portability, triggers compiler bugs, unusual environment etc) they will be
7a57b90c 1569 reported and eventually fixed.
115329f1 1570@item
7a57b90c 1571 Do not commit unrelated changes together, split them into self-contained
ce10ff8e
DB
1572 pieces. Also do not forget that if part B depends on part A, but A does not
1573 depend on B, then A can and should be committed first and separate from B.
1574 Keeping changes well split into self-contained parts makes reviewing and
1575 understanding them on the commit log mailing list easier. This also helps
1576 in case of debugging later on.
1577 Also if you have doubts about splitting or not splitting, do not hesitate to
442d1598 1578 ask/discuss it on the developer mailing list.
7a57b90c
MN
1579@item
1580 Do not change behavior of the program (renaming options etc) without
019c8838 1581 first discussing it on the ffmpeg-devel mailing list. Do not remove
7a57b90c 1582 functionality from the code. Just improve!
115329f1 1583
4c5f7207 1584 Note: Redundant code can be removed.
7a57b90c
MN
1585@item
1586 Do not commit changes to the build system (Makefiles, configure script)
019c8838 1587 which change behavior, defaults etc, without asking first. The same
7a57b90c
MN
1588 applies to compiler warning fixes, trivial looking fixes and to code
1589 maintained by other developers. We usually have a reason for doing things
019c8838 1590 the way we do. Send your changes as patches to the ffmpeg-devel mailing
7a57b90c
MN
1591 list, and if the code maintainers say OK, you may commit. This does not
1592 apply to files you wrote and/or maintain.
1593@item
1594 We refuse source indentation and other cosmetic changes if they are mixed
1595 with functional changes, such commits will be rejected and removed. Every
1596 developer has his own indentation style, you should not change it. Of course
1597 if you (re)write something, you can use your own style, even though we would
4c5f7207 1598 prefer if the indentation throughout FFmpeg was consistent (Many projects
ce10ff8e 1599 force a given indentation style - we do not.). If you really need to make
7a57b90c
MN
1600 indentation changes (try to avoid this), separate them strictly from real
1601 changes.
1602
114afa9c 1603 NOTE: If you had to put if()@{ .. @} over a large (> 5 lines) chunk of code,
ce10ff8e 1604 then either do NOT change the indentation of the inner part within (do not
019c8838 1605 move it to the right)! or do so in a separate commit
7a57b90c
MN
1606@item
1607 Always fill out the commit log message. Describe in a few lines what you
1608 changed and why. You can refer to mailing list postings if you fix a
1609 particular bug. Comments such as "fixed!" or "Changed it." are unacceptable.
1610@item
1611 If you apply a patch by someone else, include the name and email address in
1c1b5a40 1612 the log message. Since the ffmpeg-cvslog mailing list is publicly
019c8838
DB
1613 archived you should add some SPAM protection to the email address. Send an
1614 answer to ffmpeg-devel (or wherever you got the patch from) saying that
7a57b90c
MN
1615 you applied the patch.
1616@item
b092d033
BF
1617 When applying patches that have been discussed (at length) on the mailing
1618 list, reference the thread in the log message.
1619@item
5ab0f204 1620 Do NOT commit to code actively maintained by others without permission.
755bfeab 1621 Send a patch to ffmpeg-devel instead. If no one answers within a reasonable
5ab0f204 1622 timeframe (12h for build failures and security fixes, 3 days small changes,
ce10ff8e 1623 1 week for big patches) then commit your patch if you think it is OK.
5ab0f204 1624 Also note, the maintainer can simply ask for more time to review!
7a57b90c 1625@item
1c1b5a40 1626 Subscribe to the ffmpeg-cvslog mailing list. The diffs of all commits
7a57b90c
MN
1627 are sent there and reviewed by all the other developers. Bugs and possible
1628 improvements or general questions regarding commits are discussed there. We
1629 expect you to react if problems with your code are uncovered.
1630@item
1631 Update the documentation if you change behavior or add features. If you are
019c8838 1632 unsure how best to do this, send a patch to ffmpeg-devel, the documentation
7a57b90c
MN
1633 maintainer(s) will review and commit your stuff.
1634@item
0541f2c4
MN
1635 Try to keep important discussions and requests (also) on the public
1636 developer mailing list, so that all developers can benefit from them.
1637@item
4c5f7207
DB
1638 Never write to unallocated memory, never write over the end of arrays,
1639 always check values read from some untrusted source before using them
1640 as array index or other risky things.
76bec1d8
AS
1641@item
1642 Remember to check if you need to bump versions for the specific libav
f0efbde7 1643 parts (libavutil, libavcodec, libavformat) you are changing. You need
76bec1d8
AS
1644 to change the version integer and the version string.
1645 Incrementing the first component means no backward compatibility to
a940b428 1646 previous versions (e.g. removal of a function from the public API).
76bec1d8 1647 Incrementing the second component means backward compatible change
a940b428 1648 (e.g. addition of a function to the public API).
76bec1d8
AS
1649 Incrementing the third component means a noteworthy binary compatible
1650 change (e.g. encoder bug fix that matters for the decoder).
ebd32fd7 1651@item
3f1965c4
DB
1652 If you add a new codec, remember to update the changelog, add it to
1653 the supported codecs table in the documentation and bump the second
1654 component of the @file{libavcodec} version number appropriately. If
1655 it has a fourcc, add it to @file{libavformat/avienc.c}, even if it
1656 is only a decoder.
65d0bea8 1657@item
ce10ff8e
DB
1658 Do not change code to hide warnings without ensuring that the underlying
1659 logic is correct and thus the warning was inappropriate.
bca098f5
DB
1660@item
1661 If you add a new file, give it a proper license header. Do not copy and
1662 paste it from a random place, use an existing file as template.
114afa9c 1663@end enumerate
7a57b90c
MN
1664
1665We think our rules are not too hard. If you have comments, contact us.
1666
1667Note, these rules are mostly borrowed from the MPlayer project.
1668
9181577c
FB
1669@section Submitting patches
1670
ce10ff8e 1671First, (@pxref{Coding Rules}) above if you did not yet.
80d1c272 1672
6a6810b1 1673When you submit your patch, try to send a unified diff (diff '-up'
fa78d895 1674option). We cannot read other diffs :-)
9181577c 1675
e1669c5e
DB
1676Also please do not submit a patch which contains several unrelated changes.
1677Split it into separate, self-contained pieces. This does not mean splitting
1678file by file. Instead, make the patch as small as possible while still
1679keeping it as a logical unit that contains an individual change, even
1680if it spans multiple files. This makes reviewing your patches much easier
1681for us and greatly increases your chances of getting your patch applied.
7885603a 1682
9181577c 1683Run the regression tests before submitting a patch so that you can
6bf40f39 1684verify that there are no big problems.
9181577c 1685
9181577c 1686Patches should be posted as base64 encoded attachments (or any other
ce10ff8e 1687encoding which ensures that the patch will not be trashed during
115329f1 1688transmission) to the ffmpeg-devel mailing list, see
2b165e29 1689@url{http://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel}
9181577c 1690
54fcf429 1691It also helps quite a bit if you tell us what the patch does (for example
4c5f7207 1692'replaces lrint by lrintf'), and why (for example '*BSD isn't C99 compliant
54fcf429
MN
1693and has no lrint()')
1694
78a3c678 1695Also please if you send several patches, send each patch as a separate mail,
442d1598 1696do not attach several unrelated patches to the same mail.
a15bcf70 1697
dd597cd7
MN
1698@section patch submission checklist
1699
1700@enumerate
1701@item
1702 Do the regression tests pass with the patch applied?
1703@item
1704 Is the patch a unified diff?
1705@item
4a7a0908 1706 Is the patch against latest FFmpeg SVN?
dd597cd7
MN
1707@item
1708 Are you subscribed to ffmpeg-dev?
1709 (the list is subscribers only due to spam)
1710@item
1711 Have you checked that the changes are minimal, so that the same cannot be
442d1598 1712 achieved with a smaller patch and/or simpler final code?
dd597cd7 1713@item
4a7a0908 1714 If the change is to speed critical code, did you benchmark it?
dd597cd7 1715@item
b0fee7c5
DB
1716 If you did any benchmarks, did you provide them in the mail?
1717@item
442d1598 1718 Have you checked that the patch does not introduce buffer overflows or
dd597cd7
MN
1719 other security issues?
1720@item
4a7a0908
DB
1721 Is the patch created from the root of the source tree, so it can be
1722 applied with @code{patch -p0}?
dd597cd7
MN
1723@item
1724 Does the patch not mix functional and cosmetic changes?
1725@item
e300ab4e
DB
1726 Did you add tabs or trailing whitespace to the code? Both are forbidden.
1727@item
dd597cd7
MN
1728 Is the patch attached to the email you send?
1729@item
4a7a0908
DB
1730 Is the mime type of the patch correct? It should be text/x-diff or
1731 text/x-patch or at least text/plain and not application/octet-stream.
dd597cd7 1732@item
4a7a0908 1733 If the patch fixes a bug, did you provide a verbose analysis of the bug?
dd597cd7 1734@item
4a7a0908 1735 If the patch fixes a bug, did you provide enough information, including
dd597cd7 1736 a sample, so the bug can be reproduced and the fix can be verified?
1aa80145
MN
1737 Note please do not attach samples >100k to mails but rather provide a
1738 URL, you can upload to ftp://upload.mplayerhq.hu
dd597cd7
MN
1739@item
1740 Did you provide a verbose summary about what the patch does change?
1741@item
1742 Did you provide a verbose explanation why it changes things like it does?
1743@item
442d1598 1744 Did you provide a verbose summary of the user visible advantages and
dd597cd7
MN
1745 disadvantages if the patch is applied?
1746@item
1747 Did you provide an example so we can verify the new feature added by the
1748 patch easily?
1749@item
bbe94afb 1750 If you added a new file, did you insert a license header? It should be
6baa2943 1751 taken from FFmpeg, not randomly copied and pasted from somewhere else.
6e4bc6ee 1752@item
d9a3c855
MN
1753 You should maintain alphabetical order in alphabetically ordered lists as
1754 long as doing so does not break API/ABI compatibility.
1502409e
DB
1755@item
1756 Lines with similar content should be aligned vertically when doing so
1757 improves readability.
2f954ef2
MN
1758@item
1759 Did you provide a suggestion for a clear commit log message?
dd597cd7
MN
1760@end enumerate
1761
f5f11d71
MN
1762@section Patch review process
1763
1764All patches posted to ffmpeg-devel will be reviewed, unless they contain a
1765clear note that the patch is not for SVN.
1766Reviews and comments will be posted as replies to the patch on the
ce10ff8e 1767mailing list. The patch submitter then has to take care of every comment,
442d1598 1768that can be by resubmitting a changed patch or by discussion. Resubmitted
ce10ff8e 1769patches will themselves be reviewed like any other patch. If at some point
f5f11d71 1770a patch passes review with no comments then it is approved, that can for
ce10ff8e 1771simple and small patches happen immediately while large patches will generally
f5f11d71 1772have to be changed and reviewed many times before they are approved.
ce10ff8e 1773After a patch is approved it will be committed to the repository.
f5f11d71
MN
1774
1775We will review all submitted patches, but sometimes we are quite busy so
1776especially for large patches this can take several weeks.
1777
1778When resubmitting patches, please do not make any significant changes
ce10ff8e
DB
1779not related to the comments received during review. Such patches will
1780be rejected. Instead, submit significant changes or new features as
1781separate patches.
cf7f2b16 1782
9181577c
FB
1783@section Regression tests
1784
1c1b5a40 1785Before submitting a patch (or committing to the repository), you should at least
9181577c
FB
1786test that you did not break anything.
1787
4c5f7207
DB
1788The regression tests build a synthetic video stream and a synthetic
1789audio stream. These are then encoded and decoded with all codecs or
9181577c 1790formats. The CRC (or MD5) of each generated file is recorded in a
4c5f7207 1791result file. A 'diff' is launched to compare the reference results and
9181577c
FB
1792the result file.
1793
4c5f7207 1794The regression tests then go on to test the FFserver code with a
6bf40f39
PG
1795limited set of streams. It is important that this step runs correctly
1796as well.
1797
36d9b4e8 1798Run 'make test' to test all the codecs and formats.
9181577c 1799
4c5f7207 1800Run 'make fulltest' to test all the codecs, formats and FFserver.
9181577c 1801
4c5f7207
DB
1802[Of course, some patches may change the results of the regression tests. In
1803this case, the reference results of the regression tests shall be modified
9181577c
FB
1804accordingly].
1805
1806@bye