Statistics
| Branch: | Revision:

ffmpeg / doc / ffmpeg-doc.texi @ 12b6d7c0

History | View | Annotate | Download (59.7 KB)

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

    
13
FFmpeg is a very fast video and audio converter. It can also grab from
14
a live audio/video source.
15

    
16
The command line interface is designed to be intuitive, in the sense
17
that FFmpeg tries to figure out all parameters that can possibly be
18
derived automatically. You usually only have to specify the target
19
bitrate you want.
20

    
21
FFmpeg can also convert from any sample rate to any other, and resize
22
video on the fly with a high quality polyphase filter.
23

    
24
@chapter Quick Start
25

    
26
@c man begin EXAMPLES
27
@section Video and Audio grabbing
28

    
29
FFmpeg can grab video and audio from devices given that you specify the input
30
format and device.
31

    
32
@example
33
ffmpeg -f audio_device -i /dev/dsp -f video4linux2 -i /dev/video0 /tmp/out.mpg
34
@end example
35

    
36
Note that you must activate the right video source and channel before
37
launching FFmpeg with any TV viewer such as xawtv
38
(@url{http://bytesex.org/xawtv/}) by Gerd Knorr. You also
39
have to set the audio recording levels correctly with a
40
standard mixer.
41

    
42
@section X11 grabbing
43

    
44
FFmpeg can grab the X11 display.
45

    
46
@example
47
ffmpeg -f x11grab -s cif -i :0.0 /tmp/out.mpg
48
@end example
49

    
50
0.0 is display.screen number of your X11 server, same as
51
the DISPLAY environment variable.
52

    
53
@example
54
ffmpeg -f x11grab -s cif -i :0.0+10,20 /tmp/out.mpg
55
@end example
56

    
57
0.0 is display.screen number of your X11 server, same as the DISPLAY environment
58
variable. 10 is the x-offset and 20 the y-offset for the grabbing.
59

    
60
@section Video and Audio file format conversion
61

    
62
* FFmpeg can use any supported file format and protocol as input:
63

    
64
Examples:
65

    
66
* You can use YUV files as input:
67

    
68
@example
69
ffmpeg -i /tmp/test%d.Y /tmp/out.mpg
70
@end example
71

    
72
It will use the files:
73
@example
74
/tmp/test0.Y, /tmp/test0.U, /tmp/test0.V,
75
/tmp/test1.Y, /tmp/test1.U, /tmp/test1.V, etc...
76
@end example
77

    
78
The Y files use twice the resolution of the U and V files. They are
79
raw files, without header. They can be generated by all decent video
80
decoders. You must specify the size of the image with the @option{-s} option
81
if FFmpeg cannot guess it.
82

    
83
* You can input from a raw YUV420P file:
84

    
85
@example
86
ffmpeg -i /tmp/test.yuv /tmp/out.avi
87
@end example
88

    
89
test.yuv is a file containing raw YUV planar data. Each frame is composed
90
of the Y plane followed by the U and V planes at half vertical and
91
horizontal resolution.
92

    
93
* You can output to a raw YUV420P file:
94

    
95
@example
96
ffmpeg -i mydivx.avi hugefile.yuv
97
@end example
98

    
99
* You can set several input files and output files:
100

    
101
@example
102
ffmpeg -i /tmp/a.wav -s 640x480 -i /tmp/a.yuv /tmp/a.mpg
103
@end example
104

    
105
Converts the audio file a.wav and the raw YUV video file a.yuv
106
to MPEG file a.mpg.
107

    
108
* You can also do audio and video conversions at the same time:
109

    
110
@example
111
ffmpeg -i /tmp/a.wav -ar 22050 /tmp/a.mp2
112
@end example
113

    
114
Converts a.wav to MPEG audio at 22050Hz sample rate.
115

    
116
* You can encode to several formats at the same time and define a
117
mapping from input stream to output streams:
118

    
119
@example
120
ffmpeg -i /tmp/a.wav -ab 64k /tmp/a.mp2 -ab 128k /tmp/b.mp2 -map 0:0 -map 0:0
121
@end example
122

    
123
Converts a.wav to a.mp2 at 64 kbits and to b.mp2 at 128 kbits. '-map
124
file:index' specifies which input stream is used for each output
125
stream, in the order of the definition of output streams.
126

    
127
* You can transcode decrypted VOBs
128

    
129
@example
130
ffmpeg -i snatch_1.vob -f avi -vcodec mpeg4 -b 800k -g 300 -bf 2 -acodec mp3 -ab 128k snatch.avi
131
@end example
132

    
133
This is a typical DVD ripping example; the input is a VOB file, the
134
output an AVI file with MPEG-4 video and MP3 audio. Note that in this
135
command we use B-frames so the MPEG-4 stream is DivX5 compatible, and
136
GOP size is 300 which means one intra frame every 10 seconds for 29.97fps
137
input video. Furthermore, the audio stream is MP3-encoded so you need
138
to enable LAME support by passing @code{--enable-mp3lame} to configure.
139
The mapping is particularly useful for DVD transcoding
140
to get the desired audio language.
141

    
142
NOTE: To see the supported input formats, use @code{ffmpeg -formats}.
143
@c man end
144

    
145
@chapter Invocation
146

    
147
@section Syntax
148

    
149
The generic syntax is:
150

    
151
@example
152
@c man begin SYNOPSIS
153
ffmpeg [[infile options][@option{-i} @var{infile}]]... @{[outfile options] @var{outfile}@}...
154
@c man end
155
@end example
156
@c man begin DESCRIPTION
157
As a general rule, options are applied to the next specified
158
file. Therefore, order is important, and you can have the same
159
option on the command line multiple times. Each occurrence is
160
then applied to the next input or output file.
161

    
162
* To set the video bitrate of the output file to 64kbit/s:
163
@example
164
ffmpeg -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
169
ffmpeg -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
174
ffmpeg -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
179
ffmpeg -r 1 -i input.avi -r 24 output.avi
180
@end example
181

    
182
The format option may be needed for raw input files.
183

    
184
By default, FFmpeg tries to convert as losslessly as possible: It
185
uses the same audio and video parameters for the outputs as the one
186
specified for the inputs.
187
@c man end
188

    
189
@c man begin OPTIONS
190
@section Main options
191

    
192
@table @option
193
@item -L
194
Show license.
195

    
196
@item -h
197
Show help.
198

    
199
@item -version
200
Show version.
201

    
202
@item -formats
203
Show available formats, codecs, protocols, ...
204

    
205
@item -f fmt
206
Force format.
207

    
208
@item -i filename
209
input filename
210

    
211
@item -y
212
Overwrite output files.
213

    
214
@item -t duration
215
Set the recording time in seconds.
216
@code{hh:mm:ss[.xxx]} syntax is also supported.
217

    
218
@item -fs limit_size
219
Set the file size limit.
220

    
221
@item -ss position
222
Seek to given time position in seconds.
223
@code{hh:mm:ss[.xxx]} syntax is also supported.
224

    
225
@item -itsoffset offset
226
Set the input time offset in seconds.
227
@code{[-]hh:mm:ss[.xxx]} syntax is also supported.
228
This option affects all the input files that follow it.
229
The offset is added to the timestamps of the input files.
230
Specifying a positive offset means that the corresponding
231
streams are delayed by 'offset' seconds.
232

    
233
@item -title string
234
Set the title.
235

    
236
@item -timestamp time
237
Set the timestamp.
238

    
239
@item -author string
240
Set the author.
241

    
242
@item -copyright string
243
Set the copyright.
244

    
245
@item -comment string
246
Set the comment.
247

    
248
@item -album string
249
Set the album.
250

    
251
@item -track number
252
Set the track.
253

    
254
@item -year number
255
Set the year.
256

    
257
@item -v verbose
258
Control amount of logging.
259

    
260
@item -target type
261
Specify target file type ("vcd", "svcd", "dvd", "dv", "dv50", "pal-vcd",
262
"ntsc-svcd", ... ). All the format options (bitrate, codecs,
263
buffer sizes) are then set automatically. You can just type:
264

    
265
@example
266
ffmpeg -i myfile.avi -target vcd /tmp/vcd.mpg
267
@end example
268

    
269
Nevertheless you can specify additional options as long as you know
270
they do not conflict with the standard, as in:
271

    
272
@example
273
ffmpeg -i myfile.avi -target vcd -bf 2 /tmp/vcd.mpg
274
@end example
275

    
276
@item -dframes number
277
Set the number of data frames to record.
278

    
279
@item -scodec codec
280
Force subtitle codec ('copy' to copy stream).
281

    
282
@item -newsubtitle
283
Add a new subtitle stream to the current output stream.
284

    
285
@item -slang code
286
Set the ISO 639 language code (3 letters) of the current subtitle stream.
287

    
288
@end table
289

    
290
@section Video Options
291

    
292
@table @option
293
@item -b bitrate
294
Set the video bitrate in bit/s (default = 200 kb/s).
295
@item -vframes number
296
Set the number of video frames to record.
297
@item -r fps
298
Set frame rate (Hz value, fraction or abbreviation), (default = 25).
299
@item -s size
300
Set frame size. The format is @samp{wxh} (ffserver default = 160x128, ffmpeg default = same as source).
301
The following abbreviations are recognized:
302
@table @samp
303
@item sqcif
304
128x96
305
@item qcif
306
176x144
307
@item cif
308
352x288
309
@item 4cif
310
704x576
311
@item qqvga
312
160x120
313
@item qvga
314
320x240
315
@item vga
316
640x480
317
@item svga
318
800x600
319
@item xga
320
1024x768
321
@item uxga
322
1600x1200
323
@item qxga
324
2048x1536
325
@item sxga
326
1280x1024
327
@item qsxga
328
2560x2048
329
@item hsxga
330
5120x4096
331
@item wvga
332
852x480
333
@item wxga
334
1366x768
335
@item wsxga
336
1600x1024
337
@item wuxga
338
1920x1200
339
@item woxga
340
2560x1600
341
@item wqsxga
342
3200x2048
343
@item wquxga
344
3840x2400
345
@item whsxga
346
6400x4096
347
@item whuxga
348
7680x4800
349
@item cga
350
320x200
351
@item ega
352
640x350
353
@item hd480
354
852x480
355
@item hd720
356
1280x720
357
@item hd1080
358
1920x1080
359
@end table
360

    
361
@item -aspect aspect
362
Set aspect ratio (4:3, 16:9 or 1.3333, 1.7777).
363
@item -croptop size
364
Set top crop band size (in pixels).
365
@item -cropbottom size
366
Set bottom crop band size (in pixels).
367
@item -cropleft size
368
Set left crop band size (in pixels).
369
@item -cropright size
370
Set right crop band size (in pixels).
371
@item -padtop size
372
Set top pad band size (in pixels).
373
@item -padbottom size
374
Set bottom pad band size (in pixels).
375
@item -padleft size
376
Set left pad band size (in pixels).
377
@item -padright size
378
Set right pad band size (in pixels).
379
@item -padcolor (hex color)
380
Set color of padded bands. The value for padcolor is expressed
381
as a six digit hexadecimal number where the first two digits
382
represent red, the middle two digits green and last two digits
383
blue (default = 000000 (black)).
384
@item -vn
385
Disable video recording.
386
@item -bt tolerance
387
Set video bitrate tolerance (in bit/s).
388
@item -maxrate bitrate
389
Set max video bitrate tolerance (in bit/s).
390
@item -minrate bitrate
391
Set min video bitrate tolerance (in bit/s).
392
@item -bufsize size
393
Set rate control buffer size (in bits).
394
@item -vcodec codec
395
Force video codec to @var{codec}. Use the @code{copy} special value to
396
tell that the raw codec data must be copied as is.
397
@item -sameq
398
Use same video quality as source (implies VBR).
399

    
400
@item -pass n
401
Select the pass number (1 or 2). It is useful to do two pass
402
encoding. The statistics of the video are recorded in the first
403
pass and the video is generated at the exact requested bitrate
404
in the second pass.
405

    
406
@item -passlogfile file
407
Set two pass logfile name to @var{file}.
408

    
409
@item -newvideo
410
Add a new video stream to the current output stream.
411

    
412
@end table
413

    
414
@section Advanced Video Options
415

    
416
@table @option
417
@item -pix_fmt format
418
Set pixel format.
419
@item -g gop_size
420
Set the group of pictures size.
421
@item -intra
422
Use only intra frames.
423
@item -vdt n
424
Discard threshold.
425
@item -qscale q
426
Use fixed video quantizer scale (VBR).
427
@item -qmin q
428
minimum video quantizer scale (VBR)
429
@item -qmax q
430
maximum video quantizer scale (VBR)
431
@item -qdiff q
432
maximum difference between the quantizer scales (VBR)
433
@item -qblur blur
434
video quantizer scale blur (VBR)
435
@item -qcomp compression
436
video quantizer scale compression (VBR)
437

    
438
@item -lmin lambda
439
minimum video lagrange factor (VBR)
440
@item -lmax lambda
441
max video lagrange factor (VBR)
442
@item -mblmin lambda
443
minimum macroblock quantizer scale (VBR)
444
@item -mblmax lambda
445
maximum macroblock quantizer scale (VBR)
446

    
447
These four options (lmin, lmax, mblmin, mblmax) use 'lambda' units,
448
but you may use the QP2LAMBDA constant to easily convert from 'q' units:
449
@example
450
ffmpeg -i src.ext -lmax 21*QP2LAMBDA dst.ext
451
@end example
452

    
453
@item -rc_init_cplx complexity
454
initial complexity for single pass encoding
455
@item -b_qfactor factor
456
qp factor between P- and B-frames
457
@item -i_qfactor factor
458
qp factor between P- and I-frames
459
@item -b_qoffset offset
460
qp offset between P- and B-frames
461
@item -i_qoffset offset
462
qp offset between P- and I-frames
463
@item -rc_eq equation
464
Set rate control equation (@pxref{FFmpeg formula
465
evaluator}) (default = @code{tex^qComp}).
466
@item -rc_override override
467
rate control override for specific intervals
468
@item -me method
469
Set motion estimation method to @var{method}.
470
Available methods are (from lowest to best quality):
471
@table @samp
472
@item zero
473
Try just the (0, 0) vector.
474
@item phods
475
@item log
476
@item x1
477
@item epzs
478
(default method)
479
@item full
480
exhaustive search (slow and marginally better than epzs)
481
@end table
482

    
483
@item -dct_algo algo
484
Set DCT algorithm to @var{algo}. Available values are:
485
@table @samp
486
@item 0
487
FF_DCT_AUTO (default)
488
@item 1
489
FF_DCT_FASTINT
490
@item 2
491
FF_DCT_INT
492
@item 3
493
FF_DCT_MMX
494
@item 4
495
FF_DCT_MLIB
496
@item 5
497
FF_DCT_ALTIVEC
498
@end table
499

    
500
@item -idct_algo algo
501
Set IDCT algorithm to @var{algo}. Available values are:
502
@table @samp
503
@item 0
504
FF_IDCT_AUTO (default)
505
@item 1
506
FF_IDCT_INT
507
@item 2
508
FF_IDCT_SIMPLE
509
@item 3
510
FF_IDCT_SIMPLEMMX
511
@item 4
512
FF_IDCT_LIBMPEG2MMX
513
@item 5
514
FF_IDCT_PS2
515
@item 6
516
FF_IDCT_MLIB
517
@item 7
518
FF_IDCT_ARM
519
@item 8
520
FF_IDCT_ALTIVEC
521
@item 9
522
FF_IDCT_SH4
523
@item 10
524
FF_IDCT_SIMPLEARM
525
@end table
526

    
527
@item -er n
528
Set error resilience to @var{n}.
529
@table @samp
530
@item 1
531
FF_ER_CAREFUL (default)
532
@item 2
533
FF_ER_COMPLIANT
534
@item 3
535
FF_ER_AGGRESSIVE
536
@item 4
537
FF_ER_VERY_AGGRESSIVE
538
@end table
539

    
540
@item -ec bit_mask
541
Set error concealment to @var{bit_mask}. @var{bit_mask} is a bit mask of
542
the following values:
543
@table @samp
544
@item 1
545
FF_EC_GUESS_MVS (default = enabled)
546
@item 2
547
FF_EC_DEBLOCK (default = enabled)
548
@end table
549

    
550
@item -bf frames
551
Use 'frames' B-frames (supported for MPEG-1, MPEG-2 and MPEG-4).
552
@item -mbd mode
553
macroblock decision
554
@table @samp
555
@item 0
556
FF_MB_DECISION_SIMPLE: Use mb_cmp (cannot change it yet in FFmpeg).
557
@item 1
558
FF_MB_DECISION_BITS: Choose the one which needs the fewest bits.
559
@item 2
560
FF_MB_DECISION_RD: rate distortion
561
@end table
562

    
563
@item -4mv
564
Use four motion vector by macroblock (MPEG-4 only).
565
@item -part
566
Use data partitioning (MPEG-4 only).
567
@item -bug param
568
Work around encoder bugs that are not auto-detected.
569
@item -strict strictness
570
How strictly to follow the standards.
571
@item -aic
572
Enable Advanced intra coding (h263+).
573
@item -umv
574
Enable Unlimited Motion Vector (h263+)
575

    
576
@item -deinterlace
577
Deinterlace pictures.
578
@item -ilme
579
Force interlacing support in encoder (MPEG-2 and MPEG-4 only).
580
Use this option if your input file is interlaced and you want
581
to keep the interlaced format for minimum losses.
582
The alternative is to deinterlace the input stream with
583
@option{-deinterlace}, but deinterlacing introduces losses.
584
@item -psnr
585
Calculate PSNR of compressed frames.
586
@item -vstats
587
Dump video coding statistics to @file{vstats_HHMMSS.log}.
588
@item -vstats_file file
589
Dump video coding statistics to @var{file}.
590
@item -vhook module
591
Insert video processing @var{module}. @var{module} contains the module
592
name and its parameters separated by spaces.
593
@item -top n
594
top=1/bottom=0/auto=-1 field first
595
@item -dc precision
596
Intra_dc_precision.
597
@item -vtag fourcc/tag
598
Force video tag/fourcc.
599
@item -qphist
600
Show QP histogram.
601
@item -vbsf bitstream filter
602
Bitstream filters available are "dump_extra", "remove_extra", "noise".
603
@end table
604

    
605
@section Audio Options
606

    
607
@table @option
608
@item -aframes number
609
Set the number of audio frames to record.
610
@item -ar freq
611
Set the audio sampling frequency (default = 44100 Hz).
612
@item -ab bitrate
613
Set the audio bitrate in bit/s (default = 64k).
614
@item -ac channels
615
Set the number of audio channels (default = 1).
616
@item -an
617
Disable audio recording.
618
@item -acodec codec
619
Force audio codec to @var{codec}. Use the @code{copy} special value to
620
specify that the raw codec data must be copied as is.
621
@item -newaudio
622
Add a new audio track to the output file. If you want to specify parameters,
623
do so before @code{-newaudio} (@code{-acodec}, @code{-ab}, etc..).
624

    
625
Mapping will be done automatically, if the number of output streams is equal to
626
the number of input streams, else it will pick the first one that matches. You
627
can override the mapping using @code{-map} as usual.
628

    
629
Example:
630
@example
631
ffmpeg -i file.mpg -vcodec copy -acodec ac3 -ab 384k test.mpg -acodec mp2 -ab 192k -newaudio
632
@end example
633
@item -alang code
634
Set the ISO 639 language code (3 letters) of the current audio stream.
635
@end table
636

    
637
@section Advanced Audio options:
638

    
639
@table @option
640
@item -atag fourcc/tag
641
Force audio tag/fourcc.
642
@item -absf bitstream filter
643
Bitstream filters available are "dump_extra", "remove_extra", "noise", "mp3comp", "mp3decomp".
644
@end table
645

    
646
@section Subtitle options:
647

    
648
@table @option
649
@item -scodec codec
650
Force subtitle codec ('copy' to copy stream).
651
@item -newsubtitle
652
Add a new subtitle stream to the current output stream.
653
@item -slang code
654
Set the ISO 639 language code (3 letters) of the current subtitle stream.
655
@end table
656

    
657
@section Audio/Video grab options
658

    
659
@table @option
660
@item -vc channel
661
Set video grab channel (DV1394 only).
662
@item -tvstd standard
663
Set television standard (NTSC, PAL (SECAM)).
664
@item -isync
665
Synchronize read on input.
666
@end table
667

    
668
@section Advanced options
669

    
670
@table @option
671
@item -map input stream id[:input stream id]
672
Set stream mapping from input streams to output streams.
673
Just enumerate the input streams in the order you want them in the output.
674
[input stream id] sets the (input) stream to sync against.
675
@item -map_meta_data outfile:infile
676
Set meta data information of outfile from infile.
677
@item -debug
678
Print specific debug info.
679
@item -benchmark
680
Add timings for benchmarking.
681
@item -dump
682
Dump each input packet.
683
@item -hex
684
When dumping packets, also dump the payload.
685
@item -bitexact
686
Only use bit exact algorithms (for codec testing).
687
@item -ps size
688
Set packet size in bits.
689
@item -re
690
Read input at native frame rate. Mainly used to simulate a grab device.
691
@item -loop_input
692
Loop over the input stream. Currently it works only for image
693
streams. This option is used for automatic FFserver testing.
694
@item -loop_output number_of_times
695
Repeatedly loop output for formats that support looping such as animated GIF
696
(0 will loop the output infinitely).
697
@item -threads count
698
Thread count.
699
@item -vsync parameter
700
Video sync method. Video will be stretched/squeezed to match the timestamps,
701
it is done by duplicating and dropping frames. With -map you can select from
702
which stream the timestamps should be taken. You can leave either video or
703
audio unchanged and sync the remaining stream(s) to the unchanged one.
704
@item -async samples_per_second
705
Audio sync method. "Stretches/squeezes" the audio stream to match the timestamps,
706
the parameter is the maximum samples per second by which the audio is changed.
707
-async 1 is a special case where only the start of the audio stream is corrected
708
without any later correction.
709
@end table
710

    
711
@node FFmpeg formula evaluator
712
@section FFmpeg formula evaluator
713

    
714
When evaluating a rate control string, FFmpeg uses an internal formula
715
evaluator.
716

    
717
The following binary operators are available: @code{+}, @code{-},
718
@code{*}, @code{/}, @code{^}.
719

    
720
The following unary operators are available: @code{+}, @code{-},
721
@code{(...)}.
722

    
723
The following functions are available:
724
@table @var
725
@item sinh(x)
726
@item cosh(x)
727
@item tanh(x)
728
@item sin(x)
729
@item cos(x)
730
@item tan(x)
731
@item exp(x)
732
@item log(x)
733
@item squish(x)
734
@item gauss(x)
735
@item abs(x)
736
@item max(x, y)
737
@item min(x, y)
738
@item gt(x, y)
739
@item lt(x, y)
740
@item eq(x, y)
741
@item bits2qp(bits)
742
@item qp2bits(qp)
743
@end table
744

    
745
The following constants are available:
746
@table @var
747
@item PI
748
@item E
749
@item iTex
750
@item pTex
751
@item tex
752
@item mv
753
@item fCode
754
@item iCount
755
@item mcVar
756
@item var
757
@item isI
758
@item isP
759
@item isB
760
@item avgQP
761
@item qComp
762
@item avgIITex
763
@item avgPITex
764
@item avgPPTex
765
@item avgBPTex
766
@item avgTex
767
@end table
768

    
769
@c man end
770

    
771
@ignore
772

    
773
@setfilename ffmpeg
774
@settitle FFmpeg video converter
775

    
776
@c man begin SEEALSO
777
ffserver(1), ffplay(1) and the HTML documentation of @file{ffmpeg}.
778
@c man end
779

    
780
@c man begin AUTHOR
781
Fabrice Bellard
782
@c man end
783

    
784
@end ignore
785

    
786
@section Protocols
787

    
788
The filename can be @file{-} to read from standard input or to write
789
to standard output.
790

    
791
FFmpeg also handles many protocols specified with an URL syntax.
792

    
793
Use 'ffmpeg -formats' to see a list of the supported protocols.
794

    
795
The protocol @code{http:} is currently used only to communicate with
796
FFserver (see the FFserver documentation). When FFmpeg will be a
797
video player it will also be used for streaming :-)
798

    
799
@chapter Tips
800

    
801
@itemize
802
@item For streaming at very low bitrate application, use a low frame rate
803
and a small GOP size. This is especially true for RealVideo where
804
the Linux player does not seem to be very fast, so it can miss
805
frames. An example is:
806

    
807
@example
808
ffmpeg -g 3 -r 3 -t 10 -b 50k -s qcif -f rv10 /tmp/b.rm
809
@end example
810

    
811
@item  The parameter 'q' which is displayed while encoding is the current
812
quantizer. The value 1 indicates that a very good quality could
813
be achieved. The value 31 indicates the worst quality. If q=31 appears
814
too often, it means that the encoder cannot compress enough to meet
815
your bitrate. You must either increase the bitrate, decrease the
816
frame rate or decrease the frame size.
817

    
818
@item If your computer is not fast enough, you can speed up the
819
compression at the expense of the compression ratio. You can use
820
'-me zero' to speed up motion estimation, and '-intra' to disable
821
motion estimation completely (you have only I-frames, which means it
822
is about as good as JPEG compression).
823

    
824
@item To have very low audio bitrates, reduce the sampling frequency
825
(down to 22050 kHz for MPEG audio, 22050 or 11025 for AC3).
826

    
827
@item To have a constant quality (but a variable bitrate), use the option
828
'-qscale n' when 'n' is between 1 (excellent quality) and 31 (worst
829
quality).
830

    
831
@item When converting video files, you can use the '-sameq' option which
832
uses the same quality factor in the encoder as in the decoder.
833
It allows almost lossless encoding.
834

    
835
@end itemize
836

    
837

    
838
@chapter external libraries
839

    
840
FFmpeg can be hooked up with a number of external libraries to add support
841
for more formats. None of them are used by default, their use has to be
842
explicitly requested by passing the appropriate flags to @file{./configure}.
843

    
844
@section AMR
845

    
846
AMR comes in two different flavors, WB and NB. FFmpeg can make use of the
847
AMR WB (floating-point mode) and the AMR NB (floating-point mode) reference
848
decoders and encoders.
849

    
850
Go to @url{http://www.penguin.cz/~utx/amr} and follow the instructions for
851
installing the libraries. Then pass @code{--enable-amr-nb} and/or
852
@code{--enable-amr-wb} to configure to enable the libraries.
853

    
854

    
855
@chapter Supported File Formats and Codecs
856

    
857
You can use the @code{-formats} option to have an exhaustive list.
858

    
859
@section File Formats
860

    
861
FFmpeg supports the following file formats through the @code{libavformat}
862
library:
863

    
864
@multitable @columnfractions .4 .1 .1 .4
865
@item Supported File Format @tab Encoding @tab Decoding @tab Comments
866
@item MPEG audio @tab X @tab X
867
@item MPEG-1 systems @tab X  @tab  X
868
@tab muxed audio and video
869
@item MPEG-2 PS @tab X  @tab  X
870
@tab also known as @code{VOB} file
871
@item MPEG-2 TS @tab    @tab  X
872
@tab also known as DVB Transport Stream
873
@item ASF@tab X @tab X
874
@item AVI@tab X @tab X
875
@item WAV@tab X @tab X
876
@item Macromedia Flash@tab X @tab X
877
@tab Only embedded audio is decoded.
878
@item FLV              @tab  X @tab X
879
@tab Macromedia Flash video files
880
@item Real Audio and Video @tab X @tab X
881
@item Raw AC3 @tab X  @tab  X
882
@item Raw MJPEG @tab X  @tab  X
883
@item Raw MPEG video @tab X  @tab  X
884
@item Raw PCM8/16 bits, mulaw/Alaw@tab X  @tab  X
885
@item Raw CRI ADX audio @tab X  @tab  X
886
@item Raw Shorten audio @tab    @tab  X
887
@item SUN AU format @tab X  @tab  X
888
@item NUT @tab X @tab X @tab NUT Open Container Format
889
@item QuickTime        @tab X @tab  X
890
@item MPEG-4           @tab X @tab  X
891
@tab MPEG-4 is a variant of QuickTime.
892
@item Raw MPEG4 video  @tab  X @tab  X
893
@item DV               @tab  X @tab  X
894
@item 4xm              @tab    @tab X
895
@tab 4X Technologies format, used in some games.
896
@item Playstation STR  @tab    @tab X
897
@item Id RoQ           @tab    @tab X
898
@tab Used in Quake III, Jedi Knight 2, other computer games.
899
@item Interplay MVE    @tab    @tab X
900
@tab Format used in various Interplay computer games.
901
@item WC3 Movie        @tab    @tab X
902
@tab Multimedia format used in Origin's Wing Commander III computer game.
903
@item Sega FILM/CPK    @tab    @tab X
904
@tab Used in many Sega Saturn console games.
905
@item Westwood Studios VQA/AUD  @tab    @tab X
906
@tab Multimedia formats used in Westwood Studios games.
907
@item Id Cinematic (.cin) @tab    @tab X
908
@tab Used in Quake II.
909
@item FLIC format      @tab    @tab X
910
@tab .fli/.flc files
911
@item Sierra VMD       @tab    @tab X
912
@tab Used in Sierra CD-ROM games.
913
@item Sierra Online    @tab    @tab X
914
@tab .sol files used in Sierra Online games.
915
@item Matroska         @tab    @tab X
916
@item Electronic Arts Multimedia    @tab    @tab X
917
@tab Used in various EA games; files have extensions like WVE and UV2.
918
@item Nullsoft Video (NSV) format @tab    @tab X
919
@item ADTS AAC audio @tab X @tab X
920
@item Creative VOC @tab X @tab X @tab Created for the Sound Blaster Pro.
921
@item American Laser Games MM  @tab    @tab X
922
@tab Multimedia format used in games like Mad Dog McCree
923
@item AVS @tab    @tab X
924
@tab Multimedia format used by the Creature Shock game.
925
@item Smacker @tab    @tab X
926
@tab Multimedia format used by many games.
927
@item GXF @tab  X @tab X
928
@tab General eXchange Format SMPTE 360M, used by Thomson Grass Valley playout servers.
929
@item CIN @tab    @tab X
930
@tab Multimedia format used by Delphine Software games.
931
@item MXF @tab    @tab X
932
@tab Material eXchange Format SMPTE 377M, used by D-Cinema, broadcast industry.
933
@item SEQ @tab    @tab X
934
@tab Tiertex .seq files used in the DOS CDROM version of the game Flashback.
935
@item DXA @tab    @tab X
936
@tab This format is used in non-Windows version of Feeble Files game and
937
different game cutscenes repacked for use with ScummVM.
938
@item THP @tab    @tab X
939
@tab Used on the Nintendo GameCube.
940
@item C93 @tab    @tab X
941
@tab Used in the game Cyberia from Interplay.
942
@item Bethsoft VID @tab    @tab X
943
@tab Used in some games from Bethesda Softworks.
944
@item CRYO APC @tab    @tab X
945
@tab Audio format used in some games by CRYO Interactive Entertainment.
946
@end multitable
947

    
948
@code{X} means that encoding (resp. decoding) is supported.
949

    
950
@section Image Formats
951

    
952
FFmpeg can read and write images for each frame of a video sequence. The
953
following image formats are supported:
954

    
955
@multitable @columnfractions .4 .1 .1 .4
956
@item Supported Image Format @tab Encoding @tab Decoding @tab Comments
957
@item PGM, PPM     @tab X @tab X
958
@item PAM          @tab X @tab X @tab PAM is a PNM extension with alpha support.
959
@item PGMYUV       @tab X @tab X @tab PGM with U and V components in YUV 4:2:0
960
@item JPEG         @tab X @tab X @tab Progressive JPEG is not supported.
961
@item .Y.U.V       @tab X @tab X @tab one raw file per component
962
@item animated GIF @tab X @tab X @tab Only uncompressed GIFs are generated.
963
@item PNG          @tab X @tab X @tab 2 bit and 4 bit/pixel not supported yet.
964
@item Targa        @tab   @tab X @tab Targa (.TGA) image format.
965
@item TIFF         @tab X @tab X @tab YUV, JPEG and some extension is not supported yet.
966
@item SGI          @tab X @tab X @tab SGI RGB image format
967
@item PTX          @tab   @tab X @tab V.Flash PTX format
968
@end multitable
969

    
970
@code{X} means that encoding (resp. decoding) is supported.
971

    
972
@section Video Codecs
973

    
974
@multitable @columnfractions .4 .1 .1 .4
975
@item Supported Codec @tab Encoding @tab Decoding @tab Comments
976
@item MPEG-1 video           @tab  X  @tab  X
977
@item MPEG-2 video           @tab  X  @tab  X
978
@item MPEG-4                 @tab  X  @tab  X
979
@item MSMPEG4 V1             @tab  X  @tab  X
980
@item MSMPEG4 V2             @tab  X  @tab  X
981
@item MSMPEG4 V3             @tab  X  @tab  X
982
@item WMV7                   @tab  X  @tab  X
983
@item WMV8                   @tab  X  @tab  X @tab not completely working
984
@item WMV9                   @tab     @tab  X @tab not completely working
985
@item VC1                    @tab     @tab  X
986
@item H.261                  @tab  X  @tab  X
987
@item H.263(+)               @tab  X  @tab  X @tab also known as RealVideo 1.0
988
@item H.264                  @tab     @tab  X
989
@item RealVideo 1.0          @tab  X  @tab  X
990
@item RealVideo 2.0          @tab  X  @tab  X
991
@item MJPEG                  @tab  X  @tab  X
992
@item lossless MJPEG         @tab  X  @tab  X
993
@item JPEG-LS                @tab  X  @tab  X @tab fourcc: MJLS, lossless and near-lossless is supported
994
@item Apple MJPEG-B          @tab     @tab  X
995
@item Sunplus MJPEG          @tab     @tab  X @tab fourcc: SP5X
996
@item DV                     @tab  X  @tab  X
997
@item HuffYUV                @tab  X  @tab  X
998
@item FFmpeg Video 1         @tab  X  @tab  X @tab experimental lossless codec (fourcc: FFV1)
999
@item FFmpeg Snow            @tab  X  @tab  X @tab experimental wavelet codec (fourcc: SNOW)
1000
@item Asus v1                @tab  X  @tab  X @tab fourcc: ASV1
1001
@item Asus v2                @tab  X  @tab  X @tab fourcc: ASV2
1002
@item Creative YUV           @tab     @tab  X @tab fourcc: CYUV
1003
@item Sorenson Video 1       @tab  X  @tab  X @tab fourcc: SVQ1
1004
@item Sorenson Video 3       @tab     @tab  X @tab fourcc: SVQ3
1005
@item On2 VP3                @tab     @tab  X @tab still experimental
1006
@item On2 VP5                @tab     @tab  X @tab fourcc: VP50
1007
@item On2 VP6                @tab     @tab  X @tab fourcc: VP60,VP61,VP62
1008
@item Theora                 @tab  X  @tab  X @tab still experimental
1009
@item Intel Indeo 3          @tab     @tab  X
1010
@item FLV                    @tab  X  @tab  X @tab Sorenson H.263 used in Flash
1011
@item Flash Screen Video     @tab  X  @tab  X @tab fourcc: FSV1
1012
@item ATI VCR1               @tab     @tab  X @tab fourcc: VCR1
1013
@item ATI VCR2               @tab     @tab  X @tab fourcc: VCR2
1014
@item Cirrus Logic AccuPak   @tab     @tab  X @tab fourcc: CLJR
1015
@item 4X Video               @tab     @tab  X @tab Used in certain computer games.
1016
@item Sony Playstation MDEC  @tab     @tab  X
1017
@item Id RoQ                 @tab     @tab  X @tab Used in Quake III, Jedi Knight 2, other computer games.
1018
@item Xan/WC3                @tab     @tab  X @tab Used in Wing Commander III .MVE files.
1019
@item Interplay Video        @tab     @tab  X @tab Used in Interplay .MVE files.
1020
@item Apple Animation        @tab     @tab  X @tab fourcc: 'rle '
1021
@item Apple Graphics         @tab     @tab  X @tab fourcc: 'smc '
1022
@item Apple Video            @tab     @tab  X @tab fourcc: rpza
1023
@item Apple QuickDraw        @tab     @tab  X @tab fourcc: qdrw
1024
@item Cinepak                @tab     @tab  X
1025
@item Microsoft RLE          @tab     @tab  X
1026
@item Microsoft Video-1      @tab     @tab  X
1027
@item Westwood VQA           @tab     @tab  X
1028
@item Id Cinematic Video     @tab     @tab  X @tab Used in Quake II.
1029
@item Planar RGB             @tab     @tab  X @tab fourcc: 8BPS
1030
@item FLIC video             @tab     @tab  X
1031
@item Duck TrueMotion v1     @tab     @tab  X @tab fourcc: DUCK
1032
@item Duck TrueMotion v2     @tab     @tab  X @tab fourcc: TM20
1033
@item VMD Video              @tab     @tab  X @tab Used in Sierra VMD files.
1034
@item MSZH                   @tab     @tab  X @tab Part of LCL
1035
@item ZLIB                   @tab  X  @tab  X @tab Part of LCL, encoder experimental
1036
@item TechSmith Camtasia     @tab     @tab  X @tab fourcc: TSCC
1037
@item IBM Ultimotion         @tab     @tab  X @tab fourcc: ULTI
1038
@item Miro VideoXL           @tab     @tab  X @tab fourcc: VIXL
1039
@item QPEG                   @tab     @tab  X @tab fourccs: QPEG, Q1.0, Q1.1
1040
@item LOCO                   @tab     @tab  X @tab
1041
@item Winnov WNV1            @tab     @tab  X @tab
1042
@item Autodesk Animator Studio Codec  @tab     @tab  X @tab fourcc: AASC
1043
@item Fraps FPS1             @tab     @tab  X @tab
1044
@item CamStudio              @tab     @tab  X @tab fourcc: CSCD
1045
@item American Laser Games Video  @tab    @tab X @tab Used in games like Mad Dog McCree
1046
@item ZMBV                   @tab   X @tab  X @tab Encoder works only on PAL8
1047
@item AVS Video              @tab     @tab  X @tab Video encoding used by the Creature Shock game.
1048
@item Smacker Video          @tab     @tab  X @tab Video encoding used in Smacker.
1049
@item RTjpeg                 @tab     @tab  X @tab Video encoding used in NuppelVideo files.
1050
@item KMVC                   @tab     @tab  X @tab Codec used in Worms games.
1051
@item VMware Video           @tab     @tab  X @tab Codec used in videos captured by VMware.
1052
@item Cin Video              @tab     @tab  X @tab Codec used in Delphine Software games.
1053
@item Tiertex Seq Video      @tab     @tab  X @tab Codec used in DOS CDROM FlashBack game.
1054
@item DXA Video              @tab     @tab  X @tab Codec originally used in Feeble Files game.
1055
@item AVID DNxHD             @tab     @tab  X @tab aka SMPTE VC3
1056
@item C93 Video              @tab     @tab  X @tab Codec used in Cyberia game.
1057
@item THP                    @tab     @tab  X @tab Used on the Nintendo GameCube.
1058
@item Bethsoft VID           @tab     @tab  X @tab Used in some games from Bethesda Softworks.
1059
@item Renderware TXD         @tab     @tab  X @tab Texture dictionaries used by the Renderware Engine.
1060
@end multitable
1061

    
1062
@code{X} means that encoding (resp. decoding) is supported.
1063

    
1064
@section Audio Codecs
1065

    
1066
@multitable @columnfractions .4 .1 .1 .1 .7
1067
@item Supported Codec @tab Encoding @tab Decoding @tab Comments
1068
@item MPEG audio layer 2     @tab  IX  @tab  IX
1069
@item MPEG audio layer 1/3   @tab IX   @tab  IX
1070
@tab MP3 encoding is supported through the external library LAME.
1071
@item AC3                    @tab  IX  @tab  IX
1072
@tab liba52 is used internally for decoding.
1073
@item Vorbis                 @tab  X   @tab  X
1074
@item WMA V1/V2              @tab X    @tab X
1075
@item AAC                    @tab X    @tab X
1076
@tab Supported through the external library libfaac/libfaad.
1077
@item Microsoft ADPCM        @tab X    @tab X
1078
@item MS IMA ADPCM           @tab X    @tab X
1079
@item QT IMA ADPCM           @tab      @tab X
1080
@item 4X IMA ADPCM           @tab      @tab X
1081
@item G.726  ADPCM           @tab X    @tab X
1082
@item Duck DK3 IMA ADPCM     @tab      @tab X
1083
@tab Used in some Sega Saturn console games.
1084
@item Duck DK4 IMA ADPCM     @tab      @tab X
1085
@tab Used in some Sega Saturn console games.
1086
@item Westwood Studios IMA ADPCM @tab      @tab X
1087
@tab Used in Westwood Studios games like Command and Conquer.
1088
@item SMJPEG IMA ADPCM       @tab      @tab X
1089
@tab Used in certain Loki game ports.
1090
@item CD-ROM XA ADPCM        @tab      @tab X
1091
@item CRI ADX ADPCM          @tab X    @tab X
1092
@tab Used in Sega Dreamcast games.
1093
@item Electronic Arts ADPCM  @tab      @tab X
1094
@tab Used in various EA titles.
1095
@item Creative ADPCM         @tab      @tab X
1096
@tab 16 -> 4, 8 -> 4, 8 -> 3, 8 -> 2
1097
@item THP ADPCM              @tab      @tab X
1098
@tab Used on the Nintendo GameCube.
1099
@item RA144                  @tab      @tab X
1100
@tab Real 14400 bit/s codec
1101
@item RA288                  @tab      @tab X
1102
@tab Real 28800 bit/s codec
1103
@item RADnet                 @tab X    @tab IX
1104
@tab Real low bitrate AC3 codec, liba52 is used for decoding.
1105
@item AMR-NB                 @tab X    @tab X
1106
@tab Supported through an external library.
1107
@item AMR-WB                 @tab X    @tab X
1108
@tab Supported through an external library.
1109
@item DV audio               @tab      @tab X
1110
@item Id RoQ DPCM            @tab X    @tab X
1111
@tab Used in Quake III, Jedi Knight 2, other computer games.
1112
@item Interplay MVE DPCM     @tab      @tab X
1113
@tab Used in various Interplay computer games.
1114
@item Xan DPCM               @tab      @tab X
1115
@tab Used in Origin's Wing Commander IV AVI files.
1116
@item Sierra Online DPCM     @tab      @tab X
1117
@tab Used in Sierra Online game audio files.
1118
@item Apple MACE 3           @tab      @tab X
1119
@item Apple MACE 6           @tab      @tab X
1120
@item FLAC lossless audio    @tab X    @tab X
1121
@item Shorten lossless audio @tab      @tab X
1122
@item Apple lossless audio   @tab      @tab X
1123
@tab QuickTime fourcc 'alac'
1124
@item FFmpeg Sonic           @tab X    @tab X
1125
@tab experimental lossy/lossless codec
1126
@item Qdesign QDM2           @tab      @tab X
1127
@tab there are still some distortions
1128
@item Real COOK              @tab      @tab X
1129
@tab All versions except 5.1 are supported
1130
@item DSP Group TrueSpeech   @tab      @tab X
1131
@item True Audio (TTA)       @tab      @tab X
1132
@item Smacker Audio          @tab      @tab X
1133
@item WavPack Audio          @tab      @tab X
1134
@item Cin Audio              @tab      @tab X
1135
@tab Codec used in Delphine Software games.
1136
@item Intel Music Coder      @tab      @tab X
1137
@item Musepack               @tab      @tab X
1138
@tab Only SV7 is supported
1139
@item DT$ Coherent Audio     @tab      @tab X
1140
@item ATRAC 3                @tab      @tab X
1141
@end multitable
1142

    
1143
@code{X} means that encoding (resp. decoding) is supported.
1144

    
1145
@code{I} means that an integer-only version is available, too (ensures high
1146
performance on systems without hardware floating point support).
1147

    
1148
@chapter Platform Specific information
1149

    
1150
@section BSD
1151

    
1152
BSD make will not build FFmpeg, you need to install and use GNU Make
1153
(@file{gmake}).
1154

    
1155
@section Windows
1156

    
1157
To get help and instructions for using FFmpeg under Windows, check out
1158
the FFmpeg Windows Help Forum at
1159
@url{http://arrozcru.no-ip.org/ffmpeg/}.
1160

    
1161
@subsection Native Windows compilation
1162

    
1163
@itemize
1164
@item Install the current versions of MSYS and MinGW from
1165
@url{http://www.mingw.org/}. You can find detailed installation
1166
instructions in the download section and the FAQ.
1167

    
1168
NOTE: Use at least bash 3.1. Older versions are known to be failing on the
1169
configure script.
1170

    
1171
@item If you want to test the FFplay, also download
1172
the MinGW development library of SDL 1.2.x
1173
(@file{SDL-devel-1.2.x-mingw32.tar.gz}) from
1174
@url{http://www.libsdl.org}. Unpack it in a temporary directory, and
1175
unpack the archive @file{i386-mingw32msvc.tar.gz} in the MinGW tool
1176
directory. Edit the @file{sdl-config} script so that it gives the
1177
correct SDL directory when invoked.
1178

    
1179
@item Extract the current version of FFmpeg.
1180

    
1181
@item Start the MSYS shell (file @file{msys.bat}).
1182

    
1183
@item Change to the FFmpeg directory and follow
1184
 the instructions of how to compile FFmpeg (file
1185
@file{INSTALL}). Usually, launching @file{./configure} and @file{make}
1186
suffices. If you have problems using SDL, verify that
1187
@file{sdl-config} can be launched from the MSYS command line.
1188

    
1189
@item You can install FFmpeg in @file{Program Files/FFmpeg} by typing
1190
@file{make install}. Do not forget to copy @file{SDL.dll} to the place
1191
you launch @file{ffplay} from.
1192

    
1193
@end itemize
1194

    
1195
Notes:
1196
@itemize
1197

    
1198
@item The target @file{make wininstaller} can be used to create a
1199
Nullsoft based Windows installer for FFmpeg and FFplay. @file{SDL.dll}
1200
must be copied to the FFmpeg directory in order to build the
1201
installer.
1202

    
1203
@item By using @code{./configure --enable-shared} when configuring FFmpeg,
1204
you can build @file{avcodec.dll} and @file{avformat.dll}. With
1205
@code{make install} you install the FFmpeg DLLs and the associated
1206
headers in @file{Program Files/FFmpeg}.
1207

    
1208
@item Visual C++ compatibility: If you used @code{./configure --enable-shared}
1209
when configuring FFmpeg, FFmpeg tries to use the Microsoft Visual
1210
C++ @code{lib} tool to build @code{avcodec.lib} and
1211
@code{avformat.lib}. With these libraries you can link your Visual C++
1212
code directly with the FFmpeg DLLs (see below).
1213

    
1214
@end itemize
1215

    
1216
@subsection Visual C++ compatibility
1217

    
1218
FFmpeg will not compile under Visual C++ -- and it has too many
1219
dependencies on the GCC compiler to make a port viable. However,
1220
if you want to use the FFmpeg libraries in your own applications,
1221
you can still compile those applications using Visual C++. An
1222
important restriction to this is that you have to use the
1223
dynamically linked versions of the FFmpeg libraries (i.e. the
1224
DLLs), and you have to make sure that Visual-C++-compatible
1225
import libraries are created during the FFmpeg build process.
1226

    
1227
This description of how to use the FFmpeg libraries with Visual C++ is
1228
based on Visual C++ 2005 Express Edition Beta 2. If you have a different
1229
version, you might have to modify the procedures slightly.
1230

    
1231
Here are the step-by-step instructions for building the FFmpeg libraries
1232
so they can be used with Visual C++:
1233

    
1234
@enumerate
1235

    
1236
@item Install Visual C++ (if you have not done so already).
1237

    
1238
@item Install MinGW and MSYS as described above.
1239

    
1240
@item Add a call to @file{vcvars32.bat} (which sets up the environment
1241
variables for the Visual C++ tools) as the first line of
1242
@file{msys.bat}. The standard location for @file{vcvars32.bat} is
1243
@file{C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat},
1244
and the standard location for @file{msys.bat} is
1245
@file{C:\msys\1.0\msys.bat}. If this corresponds to your setup, add the
1246
following line as the first line of @file{msys.bat}:
1247

    
1248
@code{call "C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat"}
1249

    
1250
@item Start the MSYS shell (file @file{msys.bat}) and type @code{link.exe}.
1251
If you get a help message with the command line options of @code{link.exe},
1252
this means your environment variables are set up correctly, the
1253
Microsoft linker is on the path and will be used by FFmpeg to
1254
create Visual-C++-compatible import libraries.
1255

    
1256
@item Extract the current version of FFmpeg and change to the FFmpeg directory.
1257

    
1258
@item Type the command
1259
@code{./configure --enable-shared --disable-static --enable-memalign-hack}
1260
to configure and, if that did not produce any errors,
1261
type @code{make} to build FFmpeg.
1262

    
1263
@item The subdirectories @file{libavformat}, @file{libavcodec}, and
1264
@file{libavutil} should now contain the files @file{avformat.dll},
1265
@file{avformat.lib}, @file{avcodec.dll}, @file{avcodec.lib},
1266
@file{avutil.dll}, and @file{avutil.lib}, respectively. Copy the three
1267
DLLs to your System32 directory (typically @file{C:\Windows\System32}).
1268

    
1269
@end enumerate
1270

    
1271
And here is how to use these libraries with Visual C++:
1272

    
1273
@enumerate
1274

    
1275
@item Create a new console application ("File / New / Project") and then
1276
select "Win32 Console Application". On the appropriate page of the
1277
Application Wizard, uncheck the "Precompiled headers" option.
1278

    
1279
@item Write the source code for your application, or, for testing, just
1280
copy the code from an existing sample application into the source file
1281
that Visual C++ has already created for you. (Note that your source
1282
filehas to have a @code{.cpp} extension; otherwise, Visual C++ will not
1283
compile the FFmpeg headers correctly because in C mode, it does not
1284
recognize the @code{inline} keyword.)  For example, you can copy
1285
@file{output_example.c} from the FFmpeg distribution (but you will
1286
have to make minor modifications so the code will compile under
1287
C++, see below).
1288

    
1289
@item Open the "Project / Properties" dialog box. In the "Configuration"
1290
combo box, select "All Configurations" so that the changes you make will
1291
affect both debug and release builds. In the tree view on the left hand
1292
side, select "C/C++ / General", then edit the "Additional Include
1293
Directories" setting to contain the complete paths to the
1294
@file{libavformat}, @file{libavcodec}, and @file{libavutil}
1295
subdirectories of your FFmpeg directory. Note that the directories have
1296
to be separated using semicolons. Now select "Linker / General" from the
1297
tree view and edit the "Additional Library Directories" setting to
1298
contain the same three directories.
1299

    
1300
@item Still in the "Project / Properties" dialog box, select "Linker / Input"
1301
from the tree view, then add the files @file{avformat.lib},
1302
@file{avcodec.lib}, and @file{avutil.lib} to the end of the "Additional
1303
Dependencies". Note that the names of the libraries have to be separated
1304
using spaces.
1305

    
1306
@item Now, select "C/C++ / Code Generation" from the tree view. Select
1307
"Debug" in the "Configuration" combo box. Make sure that "Runtime
1308
Library" is set to "Multi-threaded Debug DLL". Then, select "Release" in
1309
the "Configuration" combo box and make sure that "Runtime Library" is
1310
set to "Multi-threaded DLL".
1311

    
1312
@item Click "OK" to close the "Project / Properties" dialog box and build
1313
the application. Hopefully, it should compile and run cleanly. If you
1314
used @file{output_example.c} as your sample application, you will get a
1315
few compiler errors, but they are easy to fix. The first type of error
1316
occurs because Visual C++ does not allow an @code{int} to be converted to
1317
an @code{enum} without a cast. To solve the problem, insert the required
1318
casts (this error occurs once for a @code{CodecID} and once for a
1319
@code{CodecType}).  The second type of error occurs because C++ requires
1320
the return value of @code{malloc} to be cast to the exact type of the
1321
pointer it is being assigned to. Visual C++ will complain that, for
1322
example, @code{(void *)} is being assigned to @code{(uint8_t *)} without
1323
an explicit cast. So insert an explicit cast in these places to silence
1324
the compiler. The third type of error occurs because the @code{snprintf}
1325
library function is called @code{_snprintf} under Visual C++.  So just
1326
add an underscore to fix the problem. With these changes,
1327
@file{output_example.c} should compile under Visual C++, and the
1328
resulting executable should produce valid video files.
1329

    
1330
@end enumerate
1331

    
1332
@subsection Cross compilation for Windows with Linux
1333

    
1334
You must use the MinGW cross compilation tools available at
1335
@url{http://www.mingw.org/}.
1336

    
1337
Then configure FFmpeg with the following options:
1338
@example
1339
./configure --target-os=mingw32 --cross-prefix=i386-mingw32msvc-
1340
@end example
1341
(you can change the cross-prefix according to the prefix chosen for the
1342
MinGW tools).
1343

    
1344
Then you can easily test FFmpeg with Wine
1345
(@url{http://www.winehq.com/}).
1346

    
1347
@subsection Compilation under Cygwin
1348

    
1349
Cygwin works very much like Unix.
1350

    
1351
Just install your Cygwin with all the "Base" packages, plus the
1352
following "Devel" ones:
1353
@example
1354
binutils, gcc-core, make, subversion
1355
@end example
1356

    
1357
Do not install binutils-20060709-1 (they are buggy on shared builds);
1358
use binutils-20050610-1 instead.
1359

    
1360
Then run
1361

    
1362
@example
1363
./configure --enable-static --disable-shared
1364
@end example
1365

    
1366
to make a static build or
1367

    
1368
@example
1369
./configure --enable-shared --disable-static
1370
@end example
1371

    
1372
to build shared libraries.
1373

    
1374
If you want to build FFmpeg with additional libraries, download Cygwin
1375
"Devel" packages for Ogg and Vorbis from any Cygwin packages repository
1376
and/or SDL, xvid, faac, faad2 packages from Cygwin Ports,
1377
(@url{http://cygwinports.dotsrc.org/}).
1378

    
1379
@subsection Crosscompilation for Windows under Cygwin
1380

    
1381
With Cygwin you can create Windows binaries that do not need the cygwin1.dll.
1382

    
1383
Just install your Cygwin as explained before, plus these additional
1384
"Devel" packages:
1385
@example
1386
gcc-mingw-core, mingw-runtime, mingw-zlib
1387
@end example
1388

    
1389
and add some special flags to your configure invocation.
1390

    
1391
For a static build run
1392
@example
1393
./configure --target-os=mingw32 --enable-memalign-hack --enable-static --disable-shared --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
1394
@end example
1395

    
1396
and for a build with shared libraries
1397
@example
1398
./configure --target-os=mingw32 --enable-memalign-hack --enable-shared --disable-static --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
1399
@end example
1400

    
1401
@section BeOS
1402

    
1403
The configure script should guess the configuration itself.
1404
Networking support is currently not finished.
1405
errno issues fixed by Andrew Bachmann.
1406

    
1407
Old stuff:
1408

    
1409
Fran├žois Revol - revol at free dot fr - April 2002
1410

    
1411
The configure script should guess the configuration itself,
1412
however I still did not test building on the net_server version of BeOS.
1413

    
1414
FFserver is broken (needs poll() implementation).
1415

    
1416
There are still issues with errno codes, which are negative in BeOS, and
1417
that FFmpeg negates when returning. This ends up turning errors into
1418
valid results, then crashes.
1419
(To be fixed)
1420

    
1421
@chapter Developers Guide
1422

    
1423
@section API
1424
@itemize @bullet
1425
@item libavcodec is the library containing the codecs (both encoding and
1426
decoding). Look at @file{libavcodec/apiexample.c} to see how to use it.
1427

    
1428
@item libavformat is the library containing the file format handling (mux and
1429
demux code for several formats). Look at @file{ffplay.c} to use it in a
1430
player. See @file{output_example.c} to use it to generate audio or video
1431
streams.
1432

    
1433
@end itemize
1434

    
1435
@section Integrating libavcodec or libavformat in your program
1436

    
1437
You can integrate all the source code of the libraries to link them
1438
statically to avoid any version problem. All you need is to provide a
1439
'config.mak' and a 'config.h' in the parent directory. See the defines
1440
generated by ./configure to understand what is needed.
1441

    
1442
You can use libavcodec or libavformat in your commercial program, but
1443
@emph{any patch you make must be published}. The best way to proceed is
1444
to send your patches to the FFmpeg mailing list.
1445

    
1446
@node Coding Rules
1447
@section Coding Rules
1448

    
1449
FFmpeg is programmed in the ISO C90 language with a few additional
1450
features from ISO C99, namely:
1451
@itemize @bullet
1452
@item
1453
the @samp{inline} keyword;
1454
@item
1455
@samp{//} comments;
1456
@item
1457
designated struct initializers (@samp{struct s x = @{ .i = 17 @};})
1458
@item
1459
compound literals (@samp{x = (struct s) @{ 17, 23 @};})
1460
@end itemize
1461

    
1462
These features are supported by all compilers we care about, so we will not
1463
accept patches to remove their use unless they absolutely do not impair
1464
clarity and performance.
1465

    
1466
All code must compile with GCC 2.95 and GCC 3.3. Currently, FFmpeg also
1467
compiles with several other compilers, such as the Compaq ccc compiler
1468
or Sun Studio 9, and we would like to keep it that way unless it would
1469
be exceedingly involved. To ensure compatibility, please do not use any
1470
additional C99 features or GCC extensions. Especially watch out for:
1471
@itemize @bullet
1472
@item
1473
mixing statements and declarations;
1474
@item
1475
@samp{long long} (use @samp{int64_t} instead);
1476
@item
1477
@samp{__attribute__} not protected by @samp{#ifdef __GNUC__} or similar;
1478
@item
1479
GCC statement expressions (@samp{(x = (@{ int y = 4; y; @})}).
1480
@end itemize
1481

    
1482
Indent size is 4.
1483
The presentation is the one specified by 'indent -i4 -kr -nut'.
1484
The TAB character is forbidden outside of Makefiles as is any
1485
form of trailing whitespace. Commits containing either will be
1486
rejected by the Subversion repository.
1487

    
1488
Main priority in FFmpeg is simplicity and small code size (=less
1489
bugs).
1490

    
1491
Comments: Use the JavaDoc/Doxygen
1492
format (see examples below) so that code documentation
1493
can be generated automatically. All nontrivial functions should have a comment
1494
above them explaining what the function does, even if it is just one sentence.
1495
All structures and their member variables should be documented, too.
1496
@example
1497
/**
1498
 * @@file mpeg.c
1499
 * MPEG codec.
1500
 * @@author ...
1501
 */
1502

    
1503
/**
1504
 * Summary sentence.
1505
 * more text ...
1506
 * ...
1507
 */
1508
typedef struct Foobar@{
1509
    int var1; /**< var1 description */
1510
    int var2; ///< var2 description
1511
    /** var3 description */
1512
    int var3;
1513
@} Foobar;
1514

    
1515
/**
1516
 * Summary sentence.
1517
 * more text ...
1518
 * ...
1519
 * @@param my_parameter description of my_parameter
1520
 * @@return return value description
1521
 */
1522
int myfunc(int my_parameter)
1523
...
1524
@end example
1525

    
1526
fprintf and printf are forbidden in libavformat and libavcodec,
1527
please use av_log() instead.
1528

    
1529
@section Development Policy
1530

    
1531
@enumerate
1532
@item
1533
   You must not commit code which breaks FFmpeg! (Meaning unfinished but
1534
   enabled code which breaks compilation or compiles but does not work or
1535
   breaks the regression tests)
1536
   You can commit unfinished stuff (for testing etc), but it must be disabled
1537
   (#ifdef etc) by default so it does not interfere with other developers'
1538
   work.
1539
@item
1540
   You do not have to over-test things. If it works for you, and you think it
1541
   should work for others, then commit. If your code has problems
1542
   (portability, triggers compiler bugs, unusual environment etc) they will be
1543
   reported and eventually fixed.
1544
@item
1545
   Do not commit unrelated changes together, split them into self-contained
1546
   pieces. Also do not forget that if part B depends on part A, but A does not
1547
   depend on B, then A can and should be committed first and separate from B.
1548
   Keeping changes well split into self-contained parts makes reviewing and
1549
   understanding them on the commit log mailing list easier. This also helps
1550
   in case of debugging later on.
1551
   Also if you have doubts about splitting or not splitting, do not hesitate to
1552
   ask/discuss it on the developer mailing list.
1553
@item
1554
   Do not change behavior of the program (renaming options etc) without
1555
   first discussing it on the ffmpeg-devel mailing list. Do not remove
1556
   functionality from the code. Just improve!
1557

    
1558
   Note: Redundant code can be removed.
1559
@item
1560
   Do not commit changes to the build system (Makefiles, configure script)
1561
   which change behavior, defaults etc, without asking first. The same
1562
   applies to compiler warning fixes, trivial looking fixes and to code
1563
   maintained by other developers. We usually have a reason for doing things
1564
   the way we do. Send your changes as patches to the ffmpeg-devel mailing
1565
   list, and if the code maintainers say OK, you may commit. This does not
1566
   apply to files you wrote and/or maintain.
1567
@item
1568
   We refuse source indentation and other cosmetic changes if they are mixed
1569
   with functional changes, such commits will be rejected and removed. Every
1570
   developer has his own indentation style, you should not change it. Of course
1571
   if you (re)write something, you can use your own style, even though we would
1572
   prefer if the indentation throughout FFmpeg was consistent (Many projects
1573
   force a given indentation style - we do not.). If you really need to make
1574
   indentation changes (try to avoid this), separate them strictly from real
1575
   changes.
1576

    
1577
   NOTE: If you had to put if()@{ .. @} over a large (> 5 lines) chunk of code,
1578
   then either do NOT change the indentation of the inner part within (do not
1579
   move it to the right)! or do so in a separate commit
1580
@item
1581
   Always fill out the commit log message. Describe in a few lines what you
1582
   changed and why. You can refer to mailing list postings if you fix a
1583
   particular bug. Comments such as "fixed!" or "Changed it." are unacceptable.
1584
@item
1585
   If you apply a patch by someone else, include the name and email address in
1586
   the log message. Since the ffmpeg-cvslog mailing list is publicly
1587
   archived you should add some SPAM protection to the email address. Send an
1588
   answer to ffmpeg-devel (or wherever you got the patch from) saying that
1589
   you applied the patch.
1590
@item
1591
   When applying patches that have been discussed (at length) on the mailing
1592
   list, reference the thread in the log message.
1593
@item
1594
    Do NOT commit to code actively maintained by others without permission.
1595
    Send a patch to ffmpeg-devel instead. If noone answers within a reasonable
1596
    timeframe (12h for build failures and security fixes, 3 days small changes,
1597
    1 week for big patches) then commit your patch if you think it is OK.
1598
    Also note, the maintainer can simply ask for more time to review!
1599
@item
1600
    Subscribe to the ffmpeg-cvslog mailing list. The diffs of all commits
1601
    are sent there and reviewed by all the other developers. Bugs and possible
1602
    improvements or general questions regarding commits are discussed there. We
1603
    expect you to react if problems with your code are uncovered.
1604
@item
1605
    Update the documentation if you change behavior or add features. If you are
1606
    unsure how best to do this, send a patch to ffmpeg-devel, the documentation
1607
    maintainer(s) will review and commit your stuff.
1608
@item
1609
    Try to keep important discussions and requests (also) on the public
1610
    developer mailing list, so that all developers can benefit from them.
1611
@item
1612
    Never write to unallocated memory, never write over the end of arrays,
1613
    always check values read from some untrusted source before using them
1614
    as array index or other risky things.
1615
@item
1616
    Remember to check if you need to bump versions for the specific libav
1617
    parts (libavutil, libavcodec, libavformat) you are changing. You need
1618
    to change the version integer and the version string.
1619
    Incrementing the first component means no backward compatibility to
1620
    previous versions (e.g. removal of a function from the public API).
1621
    Incrementing the second component means backward compatible change
1622
    (e.g. addition of a function to the public API).
1623
    Incrementing the third component means a noteworthy binary compatible
1624
    change (e.g. encoder bug fix that matters for the decoder).
1625
@item
1626
    If you add a new codec, remember to update the changelog, add it to
1627
    the supported codecs table in the documentation and bump the second
1628
    component of the @file{libavcodec} version number appropriately. If
1629
    it has a fourcc, add it to @file{libavformat/avienc.c}, even if it
1630
    is only a decoder.
1631
@item
1632
    Do not change code to hide warnings without ensuring that the underlying
1633
    logic is correct and thus the warning was inappropriate.
1634
@item
1635
    If you add a new file, give it a proper license header. Do not copy and
1636
    paste it from a random place, use an existing file as template.
1637
@end enumerate
1638

    
1639
We think our rules are not too hard. If you have comments, contact us.
1640

    
1641
Note, these rules are mostly borrowed from the MPlayer project.
1642

    
1643
@section Submitting patches
1644

    
1645
First, (@pxref{Coding Rules}) above if you did not yet.
1646

    
1647
When you submit your patch, try to send a unified diff (diff '-up'
1648
option). I cannot read other diffs :-)
1649

    
1650
Also please do not submit patches which contain several unrelated changes.
1651
Split them into individual self-contained patches; this makes reviewing
1652
them much easier.
1653

    
1654
Run the regression tests before submitting a patch so that you can
1655
verify that there are no big problems.
1656

    
1657
Patches should be posted as base64 encoded attachments (or any other
1658
encoding which ensures that the patch will not be trashed during
1659
transmission) to the ffmpeg-devel mailing list, see
1660
@url{http://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel}
1661

    
1662
It also helps quite a bit if you tell us what the patch does (for example
1663
'replaces lrint by lrintf'), and why (for example '*BSD isn't C99 compliant
1664
and has no lrint()')
1665

    
1666
Also please if you send several patches, send each patch as separate mail,
1667
do not attach several unrelated patches to the same mail.
1668

    
1669
@section patch submission checklist
1670

    
1671
@enumerate
1672
@item
1673
    Do the regression tests pass with the patch applied?
1674
@item
1675
    Is the patch a unified diff?
1676
@item
1677
    Is the patch against latest FFmpeg SVN?
1678
@item
1679
    Are you subscribed to ffmpeg-dev?
1680
    (the list is subscribers only due to spam)
1681
@item
1682
    Have you checked that the changes are minimal, so that the same cannot be
1683
    achieved with a smaller patch and/or simpler final code?
1684
@item
1685
    If the change is to speed critical code, did you benchmark it?
1686
@item
1687
    If you did any benchmarks, did you provide them in the mail?
1688
@item
1689
    Have you checked that the patch does not introduce buffer overflows or
1690
    other security issues?
1691
@item
1692
    Is the patch created from the root of the source tree, so it can be
1693
    applied with @code{patch -p0}?
1694
@item
1695
    Does the patch not mix functional and cosmetic changes?
1696
@item
1697
    Did you add tabs or trailing whitespace to the code? Both are forbidden.
1698
@item
1699
    Is the patch attached to the email you send?
1700
@item
1701
    Is the mime type of the patch correct? It should be text/x-diff or
1702
    text/x-patch or at least text/plain and not application/octet-stream.
1703
@item
1704
    If the patch fixes a bug, did you provide a verbose analysis of the bug?
1705
@item
1706
    If the patch fixes a bug, did you provide enough information, including
1707
    a sample, so the bug can be reproduced and the fix can be verified?
1708
@item
1709
    Did you provide a verbose summary about what the patch does change?
1710
@item
1711
    Did you provide a verbose explanation why it changes things like it does?
1712
@item
1713
    Did you provide a verbose summary of the user visible advantages and
1714
    disadvantages if the patch is applied?
1715
@item
1716
    Did you provide an example so we can verify the new feature added by the
1717
    patch easily?
1718
@item
1719
    If you added a new file, did you insert a license header? It should be
1720
    taken from FFmpeg, not randomly copied and pasted from somewhere else.
1721
@item
1722
    You should maintain alphabetical order in alphabetically ordered lists as
1723
    long as doing so does not break API/ABI compatibility.
1724
@item
1725
    Did you provide a suggestion for a clear commit log message?
1726
@end enumerate
1727

    
1728
@section Patch review process
1729

    
1730
All patches posted to ffmpeg-devel will be reviewed, unless they contain a
1731
clear note that the patch is not for SVN.
1732
Reviews and comments will be posted as replies to the patch on the
1733
mailing list. The patch submitter then has to take care of every comment,
1734
that can be by resubmitting a changed patch or by discussion. Resubmitted
1735
patches will themselves be reviewed like any other patch. If at some point
1736
a patch passes review with no comments then it is approved, that can for
1737
simple and small patches happen immediately while large patches will generally
1738
have to be changed and reviewed many times before they are approved.
1739
After a patch is approved it will be committed to the repository.
1740

    
1741
We will review all submitted patches, but sometimes we are quite busy so
1742
especially for large patches this can take several weeks.
1743

    
1744
When resubmitting patches, please do not make any significant changes
1745
not related to the comments received during review. Such patches will
1746
be rejected. Instead, submit  significant changes or new features as
1747
separate patches.
1748

    
1749
@section Regression tests
1750

    
1751
Before submitting a patch (or committing to the repository), you should at least
1752
test that you did not break anything.
1753

    
1754
The regression tests build a synthetic video stream and a synthetic
1755
audio stream. These are then encoded and decoded with all codecs or
1756
formats. The CRC (or MD5) of each generated file is recorded in a
1757
result file. A 'diff' is launched to compare the reference results and
1758
the result file.
1759

    
1760
The regression tests then go on to test the FFserver code with a
1761
limited set of streams. It is important that this step runs correctly
1762
as well.
1763

    
1764
Run 'make test' to test all the codecs and formats.
1765

    
1766
Run 'make fulltest' to test all the codecs, formats and FFserver.
1767

    
1768
[Of course, some patches may change the results of the regression tests. In
1769
this case, the reference results of the regression tests shall be modified
1770
accordingly].
1771

    
1772
@bye