[libav.git] / doc / ffmpeg-doc.texi
1 \input texinfo @c -*- texinfo -*-
3 @settitle FFmpeg Documentation
4 @titlepage
5 @sp 7
6 @center @titlefont{FFmpeg Documentation}
7 @sp 3
8 @end titlepage
11 @chapter Introduction
13 FFmpeg is a very fast video and audio converter. It can also grab from
14 a live audio/video source.
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.
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.
24 @chapter Quick Start
26 @c man begin EXAMPLES
27 @section Video and Audio grabbing
29 FFmpeg can use a video4linux compatible video source and any Open Sound
30 System audio source:
32 @example
33 ffmpeg /tmp/out.mpg
34 @end example
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.
42 @section Video and Audio file format conversion
44 * FFmpeg can use any supported file format and protocol as input:
46 Examples:
48 * You can use YUV files as input:
50 @example
51 ffmpeg -i /tmp/test%d.Y /tmp/out.mpg
52 @end example
54 It will use the files:
55 @example
56 /tmp/test0.Y, /tmp/test0.U, /tmp/test0.V,
57 /tmp/test1.Y, /tmp/test1.U, /tmp/test1.V, etc...
58 @end example
60 The Y files use twice the resolution of the U and V files. They are
61 raw files, without header. They can be generated by all decent video
62 decoders. You must specify the size of the image with the @option{-s} option
63 if FFmpeg cannot guess it.
65 * You can input from a raw YUV420P file:
67 @example
68 ffmpeg -i /tmp/test.yuv /tmp/out.avi
69 @end example
71 test.yuv is a file containing raw YUV planar data. Each frame is composed
72 of the Y plane followed by the U and V planes at half vertical and
73 horizontal resolution.
75 * You can output to a raw YUV420P file:
77 @example
78 ffmpeg -i mydivx.avi hugefile.yuv
79 @end example
81 * You can set several input files and output files:
83 @example
84 ffmpeg -i /tmp/a.wav -s 640x480 -i /tmp/a.yuv /tmp/a.mpg
85 @end example
87 Converts the audio file a.wav and the raw YUV video file a.yuv
88 to MPEG file a.mpg.
90 * You can also do audio and video conversions at the same time:
92 @example
93 ffmpeg -i /tmp/a.wav -ar 22050 /tmp/a.mp2
94 @end example
96 Converts a.wav to MPEG audio at 22050Hz sample rate.
98 * You can encode to several formats at the same time and define a
99 mapping from input stream to output streams:
101 @example
102 ffmpeg -i /tmp/a.wav -ab 64 /tmp/a.mp2 -ab 128 /tmp/b.mp2 -map 0:0 -map 0:0
103 @end example
105 Converts a.wav to a.mp2 at 64 kbits and to b.mp2 at 128 kbits. '-map
106 file:index' specifies which input stream is used for each output
107 stream, in the order of the definition of output streams.
109 * You can transcode decrypted VOBs
111 @example
112 ffmpeg -i snatch_1.vob -f avi -vcodec mpeg4 -b 800k -g 300 -bf 2 -acodec mp3 -ab 128 snatch.avi
113 @end example
115 This is a typical DVD ripping example; the input is a VOB file, the
116 output an AVI file with MPEG-4 video and MP3 audio. Note that in this
117 command we use B-frames so the MPEG-4 stream is DivX5 compatible, and
118 GOP size is 300 which means one intra frame every 10 seconds for 29.97fps
119 input video. Furthermore, the audio stream is MP3-encoded so you need
120 to enable LAME support by passing @code{--enable-mp3lame} to configure.
121 The mapping is particularly useful for DVD transcoding
122 to get the desired audio language.
124 NOTE: To see the supported input formats, use @code{ffmpeg -formats}.
125 @c man end
127 @chapter Invocation
129 @section Syntax
131 The generic syntax is:
133 @example
134 @c man begin SYNOPSIS
135 ffmpeg [[infile options][@option{-i} @var{infile}]]... @{[outfile options] @var{outfile}@}...
136 @c man end
137 @end example
138 @c man begin DESCRIPTION
139 If no input file is given, audio/video grabbing is done.
141 As a general rule, options are applied to the next specified
142 file. Therefore, order is important, and you can have the same
143 option on the command line multiple times. Each occurrence is
144 then applied to the next input or output file.
146 * To set the video bitrate of the output file to 64kbit/s:
147 @example
148 ffmpeg -i input.avi -b 64k output.avi
149 @end example
151 * To force the frame rate of the input and output file to 24 fps:
152 @example
153 ffmpeg -r 24 -i input.avi output.avi
154 @end example
156 * To force the frame rate of the output file to 24 fps:
157 @example
158 ffmpeg -i input.avi -r 24 output.avi
159 @end example
161 * To force the frame rate of input file to 1 fps and the output file to 24 fps:
162 @example
163 ffmpeg -r 1 -i input.avi -r 24 output.avi
164 @end example
166 The format option may be needed for raw input files.
168 By default, FFmpeg tries to convert as losslessly as possible: It
169 uses the same audio and video parameters for the outputs as the one
170 specified for the inputs.
171 @c man end
173 @c man begin OPTIONS
174 @section Main options
176 @table @option
177 @item -L
178 Show license.
180 @item -h
181 Show help.
183 @item -version
184 Show version.
186 @item -formats
187 Show available formats, codecs, protocols, ...
189 @item -f fmt
190 Force format.
192 @item -i filename
193 input filename
195 @item -y
196 Overwrite output files.
198 @item -t duration
199 Set the recording time in seconds.
200 @code{hh:mm:ss[.xxx]} syntax is also supported.
202 @item -fs limit_size
203 Set the file size limit.
205 @item -ss position
206 Seek to given time position in seconds.
207 @code{hh:mm:ss[.xxx]} syntax is also supported.
209 @item -itsoffset offset
210 Set the input time offset in seconds.
211 @code{[-]hh:mm:ss[.xxx]} syntax is also supported.
212 This option affects all the input files that follow it.
213 The offset is added to the timestamps of the input files.
214 Specifying a positive offset means that the corresponding
215 streams are delayed by 'offset' seconds.
217 @item -title string
218 Set the title.
220 @item -timestamp time
221 Set the timestamp.
223 @item -author string
224 Set the author.
226 @item -copyright string
227 Set the copyright.
229 @item -comment string
230 Set the comment.
232 @item -album string
233 Set the album.
235 @item -track number
236 Set the track.
238 @item -year number
239 Set the year.
241 @item -v verbose
242 Control amount of logging.
244 @item -target type
245 Specify target file type ("vcd", "svcd", "dvd", "dv", "dv50", "pal-vcd",
246 "ntsc-svcd", ... ). All the format options (bitrate, codecs,
247 buffer sizes) are then set automatically. You can just type:
249 @example
250 ffmpeg -i myfile.avi -target vcd /tmp/vcd.mpg
251 @end example
253 Nevertheless you can specify additional options as long as you know
254 they do not conflict with the standard, as in:
256 @example
257 ffmpeg -i myfile.avi -target vcd -bf 2 /tmp/vcd.mpg
258 @end example
260 @item -dframes number
261 Set the number of data frames to record.
263 @item -scodec codec
264 Force subtitle codec ('copy' to copy stream).
266 @item -newsubtitle
267 Add a new subtitle stream to the current output stream.
269 @item -slang code
270 Set the ISO 639 language code (3 letters) of the current subtitle stream.
272 @end table
274 @section Video Options
276 @table @option
277 @item -b bitrate
278 Set the video bitrate in bit/s (default = 200 kb/s).
279 @item -vframes number
280 Set the number of video frames to record.
281 @item -r fps
282 Set frame rate (Hz value, fraction or abbreviation), (default = 25).
283 @item -s size
284 Set frame size. The format is @samp{wxh} (default = 160x128).
285 The following abbreviations are recognized:
286 @table @samp
287 @item sqcif
288 128x96
289 @item qcif
290 176x144
291 @item cif
292 352x288
293 @item 4cif
294 704x576
295 @end table
297 @item -aspect aspect
298 Set aspect ratio (4:3, 16:9 or 1.3333, 1.7777).
299 @item -croptop size
300 Set top crop band size (in pixels).
301 @item -cropbottom size
302 Set bottom crop band size (in pixels).
303 @item -cropleft size
304 Set left crop band size (in pixels).
305 @item -cropright size
306 Set right crop band size (in pixels).
307 @item -padtop size
308 Set top pad band size (in pixels).
309 @item -padbottom size
310 Set bottom pad band size (in pixels).
311 @item -padleft size
312 Set left pad band size (in pixels).
313 @item -padright size
314 Set right pad band size (in pixels).
315 @item -padcolor (hex color)
316 Set color of padded bands. The value for padcolor is expressed
317 as a six digit hexadecimal number where the first two digits
318 represent red, the middle two digits green and last two digits
319 blue (default = 000000 (black)).
320 @item -vn
321 Disable video recording.
322 @item -bt tolerance
323 Set video bitrate tolerance (in bit/s).
324 @item -maxrate bitrate
325 Set max video bitrate tolerance (in bit/s).
326 @item -minrate bitrate
327 Set min video bitrate tolerance (in bit/s).
328 @item -bufsize size
329 Set rate control buffer size (in bits).
330 @item -vcodec codec
331 Force video codec to @var{codec}. Use the @code{copy} special value to
332 tell that the raw codec data must be copied as is.
333 @item -sameq
334 Use same video quality as source (implies VBR).
336 @item -pass n
337 Select the pass number (1 or 2). It is useful to do two pass
338 encoding. The statistics of the video are recorded in the first
339 pass and the video is generated at the exact requested bitrate
340 in the second pass.
342 @item -passlogfile file
343 Set two pass logfile name to @var{file}.
345 @item -newvideo
346 Add a new video stream to the current output stream.
348 @end table
350 @section Advanced Video Options
352 @table @option
353 @item -pix_fmt format
354 Set pixel format.
355 @item -g gop_size
356 Set the group of pictures size.
357 @item -intra
358 Use only intra frames.
359 @item -vdt n
360 Discard threshold.
361 @item -qscale q
362 Use fixed video quantizer scale (VBR).
363 @item -qmin q
364 minimum video quantizer scale (VBR)
365 @item -qmax q
366 maximum video quantizer scale (VBR)
367 @item -qdiff q
368 maximum difference between the quantizer scales (VBR)
369 @item -qblur blur
370 video quantizer scale blur (VBR)
371 @item -qcomp compression
372 video quantizer scale compression (VBR)
374 @item -lmin lambda
375 minimum video lagrange factor (VBR)
376 @item -lmax lambda
377 max video lagrange factor (VBR)
378 @item -mblmin lambda
379 minimum macroblock quantizer scale (VBR)
380 @item -mblmax lambda
381 maximum macroblock quantizer scale (VBR)
383 These four options (lmin, lmax, mblmin, mblmax) use 'lambda' units,
384 but you may use the QP2LAMBDA constant to easily convert from 'q' units:
385 @example
386 ffmpeg -i src.ext -lmax 21*QP2LAMBDA dst.ext
387 @end example
389 @item -rc_init_cplx complexity
390 initial complexity for single pass encoding
391 @item -b_qfactor factor
392 qp factor between P- and B-frames
393 @item -i_qfactor factor
394 qp factor between P- and I-frames
395 @item -b_qoffset offset
396 qp offset between P- and B-frames
397 @item -i_qoffset offset
398 qp offset between P- and I-frames
399 @item -rc_eq equation
400 Set rate control equation (@pxref{FFmpeg formula
401 evaluator}) (default = @code{tex^qComp}).
402 @item -rc_override override
403 rate control override for specific intervals
404 @item -me method
405 Set motion estimation method to @var{method}.
406 Available methods are (from lowest to best quality):
407 @table @samp
408 @item zero
409 Try just the (0, 0) vector.
410 @item phods
411 @item log
412 @item x1
413 @item epzs
414 (default method)
415 @item full
416 exhaustive search (slow and marginally better than epzs)
417 @end table
419 @item -dct_algo algo
420 Set DCT algorithm to @var{algo}. Available values are:
421 @table @samp
422 @item 0
423 FF_DCT_AUTO (default)
424 @item 1
426 @item 2
428 @item 3
430 @item 4
432 @item 5
434 @end table
436 @item -idct_algo algo
437 Set IDCT algorithm to @var{algo}. Available values are:
438 @table @samp
439 @item 0
440 FF_IDCT_AUTO (default)
441 @item 1
443 @item 2
445 @item 3
447 @item 4
449 @item 5
451 @item 6
453 @item 7
455 @item 8
457 @item 9
459 @item 10
461 @end table
463 @item -er n
464 Set error resilience to @var{n}.
465 @table @samp
466 @item 1
467 FF_ER_CAREFUL (default)
468 @item 2
470 @item 3
472 @item 4
474 @end table
476 @item -ec bit_mask
477 Set error concealment to @var{bit_mask}. @var{bit_mask} is a bit mask of
478 the following values:
479 @table @samp
480 @item 1
481 FF_EC_GUESS_MVS (default = enabled)
482 @item 2
483 FF_EC_DEBLOCK (default = enabled)
484 @end table
486 @item -bf frames
487 Use 'frames' B-frames (supported for MPEG-1, MPEG-2 and MPEG-4).
488 @item -mbd mode
489 macroblock decision
490 @table @samp
491 @item 0
492 FF_MB_DECISION_SIMPLE: Use mb_cmp (cannot change it yet in FFmpeg).
493 @item 1
494 FF_MB_DECISION_BITS: Choose the one which needs the fewest bits.
495 @item 2
496 FF_MB_DECISION_RD: rate distortion
497 @end table
499 @item -4mv
500 Use four motion vector by macroblock (MPEG-4 only).
501 @item -part
502 Use data partitioning (MPEG-4 only).
503 @item -bug param
504 Work around encoder bugs that are not auto-detected.
505 @item -strict strictness
506 How strictly to follow the standards.
507 @item -aic
508 Enable Advanced intra coding (h263+).
509 @item -umv
510 Enable Unlimited Motion Vector (h263+)
512 @item -deinterlace
513 Deinterlace pictures.
514 @item -ilme
515 Force interlacing support in encoder (MPEG-2 and MPEG-4 only).
516 Use this option if your input file is interlaced and you want
517 to keep the interlaced format for minimum losses.
518 The alternative is to deinterlace the input stream with
519 @option{-deinterlace}, but deinterlacing introduces losses.
520 @item -psnr
521 Calculate PSNR of compressed frames.
522 @item -vstats
523 Dump video coding statistics to @file{vstats_HHMMSS.log}.
524 @item -vhook module
525 Insert video processing @var{module}. @var{module} contains the module
526 name and its parameters separated by spaces.
527 @item -top n
528 top=1/bottom=0/auto=-1 field first
529 @item -dc precision
530 Intra_dc_precision.
531 @item -vtag fourcc/tag
532 Force video tag/fourcc.
533 @item -qphist
534 Show QP histogram.
535 @item -vbsf bitstream filter
536 Bitstream filters available are "dump_extra", "remove_extra", "noise".
537 @end table
539 @section Audio Options
541 @table @option
542 @item -aframes number
543 Set the number of audio frames to record.
544 @item -ar freq
545 Set the audio sampling frequency (default = 44100 Hz).
546 @item -ab bitrate
547 Set the audio bitrate in kbit/s (default = 64).
548 @item -ac channels
549 Set the number of audio channels (default = 1).
550 @item -an
551 Disable audio recording.
552 @item -acodec codec
553 Force audio codec to @var{codec}. Use the @code{copy} special value to
554 specify that the raw codec data must be copied as is.
555 @item -newaudio
556 Add a new audio track to the output file. If you want to specify parameters,
557 do so before @code{-newaudio} (@code{-acodec}, @code{-ab}, etc..).
559 Mapping will be done automatically, if the number of output streams is equal to
560 the number of input streams, else it will pick the first one that matches. You
561 can override the mapping using @code{-map} as usual.
563 Example:
564 @example
565 ffmpeg -i file.mpg -vcodec copy -acodec ac3 -ab 384 test.mpg -acodec mp2 -ab 192 -newaudio
566 @end example
567 @item -alang code
568 Set the ISO 639 language code (3 letters) of the current audio stream.
569 @end table
571 @section Advanced Audio options:
573 @table @option
574 @item -atag fourcc/tag
575 Force audio tag/fourcc.
576 @item -absf bitstream filter
577 Bitstream filters available are "dump_extra", "remove_extra", "noise", "mp3comp", "mp3decomp".
578 @end table
580 @section Subtitle options:
582 @table @option
583 @item -scodec codec
584 Force subtitle codec ('copy' to copy stream).
585 @item -newsubtitle
586 Add a new subtitle stream to the current output stream.
587 @item -slang code
588 Set the ISO 639 language code (3 letters) of the current subtitle stream.
589 @end table
591 @section Audio/Video grab options
593 @table @option
594 @item -vd device
595 sEt video grab device (e.g. @file{/dev/video0}).
596 @item -vc channel
597 Set video grab channel (DV1394 only).
598 @item -tvstd standard
599 Set television standard (NTSC, PAL (SECAM)).
600 @item -dv1394
601 Set DV1394 grab.
602 @item -ad device
603 Set audio device (e.g. @file{/dev/dsp}).
604 @item -grab format
605 Request grabbing using.
606 @item -gd device
607 Set grab device.
608 @end table
610 @section Advanced options
612 @table @option
613 @item -map input stream id[:input stream id]
614 Set stream mapping from input streams to output streams.
615 Just enumerate the input streams in the order you want them in the output.
616 [input stream id] sets the (input) stream to sync against.
617 @item -map_meta_data outfile:infile
618 Set meta data information of outfile from infile.
619 @item -debug
620 Print specific debug info.
621 @item -benchmark
622 Add timings for benchmarking.
623 @item -dump
624 Dump each input packet.
625 @item -hex
626 When dumping packets, also dump the payload.
627 @item -bitexact
628 Only use bit exact algorithms (for codec testing).
629 @item -ps size
630 Set packet size in bits.
631 @item -re
632 Read input at native frame rate. Mainly used to simulate a grab device.
633 @item -loop_input
634 Loop over the input stream. Currently it works only for image
635 streams. This option is used for automatic FFserver testing.
636 @item -loop_output number_of_times
637 Repeatedly loop output for formats that support looping such as animated GIF
638 (0 will loop the output infinitely).
639 @item -threads count
640 Thread count.
641 @item -vsync parameter
642 Video sync method. Video will be stretched/squeezed to match the timestamps,
643 it is done by duplicating and dropping frames. With -map you can select from
644 which stream the timestamps should be taken. You can leave either video or
645 audio unchanged and sync the remaining stream(s) to the unchanged one.
646 @item -async samples_per_second
647 Audio sync method. "Stretches/squeezes" the audio stream to match the timestamps,
648 the parameter is the maximum samples per second by which the audio is changed.
649 -async 1 is a special case where only the start of the audio stream is corrected
650 without any later correction.
651 @end table
653 @node FFmpeg formula evaluator
654 @section FFmpeg formula evaluator
656 When evaluating a rate control string, FFmpeg uses an internal formula
657 evaluator.
659 The following binary operators are available: @code{+}, @code{-},
660 @code{*}, @code{/}, @code{^}.
662 The following unary operators are available: @code{+}, @code{-},
663 @code{(...)}.
665 The following functions are available:
666 @table @var
667 @item sinh(x)
668 @item cosh(x)
669 @item tanh(x)
670 @item sin(x)
671 @item cos(x)
672 @item tan(x)
673 @item exp(x)
674 @item log(x)
675 @item squish(x)
676 @item gauss(x)
677 @item abs(x)
678 @item max(x, y)
679 @item min(x, y)
680 @item gt(x, y)
681 @item lt(x, y)
682 @item eq(x, y)
683 @item bits2qp(bits)
684 @item qp2bits(qp)
685 @end table
687 The following constants are available:
688 @table @var
689 @item PI
690 @item E
691 @item iTex
692 @item pTex
693 @item tex
694 @item mv
695 @item fCode
696 @item iCount
697 @item mcVar
698 @item var
699 @item isI
700 @item isP
701 @item isB
702 @item avgQP
703 @item qComp
704 @item avgIITex
705 @item avgPITex
706 @item avgPPTex
707 @item avgBPTex
708 @item avgTex
709 @end table
711 @c man end
713 @ignore
715 @setfilename ffmpeg
716 @settitle FFmpeg video converter
718 @c man begin SEEALSO
719 ffserver(1), ffplay(1) and the HTML documentation of @file{ffmpeg}.
720 @c man end
722 @c man begin AUTHOR
723 Fabrice Bellard
724 @c man end
726 @end ignore
728 @section Protocols
730 The filename can be @file{-} to read from standard input or to write
731 to standard output.
733 FFmpeg also handles many protocols specified with an URL syntax.
735 Use 'ffmpeg -formats' to see a list of the supported protocols.
737 The protocol @code{http:} is currently used only to communicate with
738 FFserver (see the FFserver documentation). When FFmpeg will be a
739 video player it will also be used for streaming :-)
741 @chapter Tips
743 @itemize
744 @item For streaming at very low bitrate application, use a low frame rate
745 and a small GOP size. This is especially true for RealVideo where
746 the Linux player does not seem to be very fast, so it can miss
747 frames. An example is:
749 @example
750 ffmpeg -g 3 -r 3 -t 10 -b 50k -s qcif -f rv10 /tmp/b.rm
751 @end example
753 @item The parameter 'q' which is displayed while encoding is the current
754 quantizer. The value 1 indicates that a very good quality could
755 be achieved. The value 31 indicates the worst quality. If q=31 appears
756 too often, it means that the encoder cannot compress enough to meet
757 your bitrate. You must either increase the bitrate, decrease the
758 frame rate or decrease the frame size.
760 @item If your computer is not fast enough, you can speed up the
761 compression at the expense of the compression ratio. You can use
762 '-me zero' to speed up motion estimation, and '-intra' to disable
763 motion estimation completely (you have only I-frames, which means it
764 is about as good as JPEG compression).
766 @item To have very low audio bitrates, reduce the sampling frequency
767 (down to 22050 kHz for MPEG audio, 22050 or 11025 for AC3).
769 @item To have a constant quality (but a variable bitrate), use the option
770 '-qscale n' when 'n' is between 1 (excellent quality) and 31 (worst
771 quality).
773 @item When converting video files, you can use the '-sameq' option which
774 uses the same quality factor in the encoder as in the decoder.
775 It allows almost lossless encoding.
777 @end itemize
780 @chapter external libraries
782 FFmpeg can be hooked up with a number of external libraries to add support
783 for more formats.
785 @section AMR
787 AMR comes in two different flavors, WB and NB. FFmpeg can make use of the
788 AMR WB (floating-point mode) and the AMR NB (both floating-point and
789 fixed-point mode) reference decoders and encoders.
791 @itemize
793 @item For AMR WB floating-point download TS26.204 V5.1.0 from
794 @url{http://www.3gpp.org/ftp/Specs/archive/26_series/26.204/26204-510.zip}
795 and extract the source to @file{libavcodec/amrwb_float/}.
797 @item For AMR NB floating-point download TS26.104 REL-5 V5.1.0 from
798 @url{http://www.3gpp.org/ftp/Specs/archive/26_series/26.104/26104-510.zip}
799 and extract the source to @file{libavcodec/amr_float/}.
800 If you try this on Alpha, you may need to change @code{Word32} to
801 @code{int} in @file{amr/typedef.h}.
803 @item For AMR NB fixed-point download TS26.073 REL-5 V5.1.0 from
804 @url{http://www.3gpp.org/ftp/Specs/archive/26_series/26.073/26073-510.zip}
805 and extract the source to @file{libavcodec/amr}.
806 You must also add @code{-DMMS_IO} and remove @code{-pedantic-errors}
807 to/from @code{CFLAGS} in @file{libavcodec/amr/makefile}, i.e.
808 ``@code{CFLAGS = -Wall -I. \$(CFLAGS_\$(MODE)) -D\$(VAD) -DMMS_IO}''.
810 @end itemize
813 @chapter Supported File Formats and Codecs
815 You can use the @code{-formats} option to have an exhaustive list.
817 @section File Formats
819 FFmpeg supports the following file formats through the @code{libavformat}
820 library:
822 @multitable @columnfractions .4 .1 .1 .4
823 @item Supported File Format @tab Encoding @tab Decoding @tab Comments
824 @item MPEG audio @tab X @tab X
825 @item MPEG-1 systems @tab X @tab X
826 @tab muxed audio and video
827 @item MPEG-2 PS @tab X @tab X
828 @tab also known as @code{VOB} file
829 @item MPEG-2 TS @tab @tab X
830 @tab also known as DVB Transport Stream
831 @item ASF@tab X @tab X
832 @item AVI@tab X @tab X
833 @item WAV@tab X @tab X
834 @item Macromedia Flash@tab X @tab X
835 @tab Only embedded audio is decoded.
836 @item FLV @tab X @tab X
837 @tab Macromedia Flash video files
838 @item Real Audio and Video @tab X @tab X
839 @item Raw AC3 @tab X @tab X
840 @item Raw MJPEG @tab X @tab X
841 @item Raw MPEG video @tab X @tab X
842 @item Raw PCM8/16 bits, mulaw/Alaw@tab X @tab X
843 @item Raw CRI ADX audio @tab X @tab X
844 @item Raw Shorten audio @tab @tab X
845 @item SUN AU format @tab X @tab X
846 @item NUT @tab X @tab X @tab NUT Open Container Format
847 @item QuickTime @tab X @tab X
848 @item MPEG-4 @tab X @tab X
849 @tab MPEG-4 is a variant of QuickTime.
850 @item Raw MPEG4 video @tab X @tab X
851 @item DV @tab X @tab X
852 @item 4xm @tab @tab X
853 @tab 4X Technologies format, used in some games.
854 @item Playstation STR @tab @tab X
855 @item Id RoQ @tab @tab X
856 @tab Used in Quake III, Jedi Knight 2, other computer games.
857 @item Interplay MVE @tab @tab X
858 @tab Format used in various Interplay computer games.
859 @item WC3 Movie @tab @tab X
860 @tab Multimedia format used in Origin's Wing Commander III computer game.
861 @item Sega FILM/CPK @tab @tab X
862 @tab Used in many Sega Saturn console games.
863 @item Westwood Studios VQA/AUD @tab @tab X
864 @tab Multimedia formats used in Westwood Studios games.
865 @item Id Cinematic (.cin) @tab @tab X
866 @tab Used in Quake II.
867 @item FLIC format @tab @tab X
868 @tab .fli/.flc files
869 @item Sierra VMD @tab @tab X
870 @tab Used in Sierra CD-ROM games.
871 @item Sierra Online @tab @tab X
872 @tab .sol files used in Sierra Online games.
873 @item Matroska @tab @tab X
874 @item Electronic Arts Multimedia @tab @tab X
875 @tab Used in various EA games; files have extensions like WVE and UV2.
876 @item Nullsoft Video (NSV) format @tab @tab X
877 @item ADTS AAC audio @tab X @tab X
878 @item Creative VOC @tab X @tab X @tab Created for the Sound Blaster Pro.
879 @item American Laser Games MM @tab @tab X
880 @tab Multimedia format used in games like Mad Dog McCree
881 @item AVS @tab @tab X
882 @tab Multimedia format used by the Creature Shock game.
883 @item Smacker @tab @tab X
884 @tab Multimedia format used by many games.
885 @item GXF @tab X @tab X
886 @tab General eXchange Format SMPTE 360M, used by Thomson Grass Valley playout servers.
887 @item CIN @tab @tab X
888 @tab Multimedia format used by Delphine Software games.
889 @item MXF @tab @tab X
890 @tab Material eXchange Format SMPTE 377M, used by D-Cinema, broadcast industry.
891 @item SEQ @tab @tab X
892 @tab Tiertex .seq files used in the DOS CDROM version of the game Flashback.
893 @end multitable
895 @code{X} means that encoding (resp. decoding) is supported.
897 @section Image Formats
899 FFmpeg can read and write images for each frame of a video sequence. The
900 following image formats are supported:
902 @multitable @columnfractions .4 .1 .1 .4
903 @item Supported Image Format @tab Encoding @tab Decoding @tab Comments
904 @item PGM, PPM @tab X @tab X
905 @item PAM @tab X @tab X @tab PAM is a PNM extension with alpha support.
906 @item PGMYUV @tab X @tab X @tab PGM with U and V components in YUV 4:2:0
907 @item JPEG @tab X @tab X @tab Progressive JPEG is not supported.
908 @item .Y.U.V @tab X @tab X @tab one raw file per component
909 @item animated GIF @tab X @tab X @tab Only uncompressed GIFs are generated.
910 @item PNG @tab X @tab X @tab 2 bit and 4 bit/pixel not supported yet.
911 @item Targa @tab @tab X @tab Targa (.TGA) image format.
912 @item TIFF @tab @tab X @tab Only 24 bit/pixel images are supported.
913 @item SGI @tab X @tab X @tab SGI RGB image format
914 @end multitable
916 @code{X} means that encoding (resp. decoding) is supported.
918 @section Video Codecs
920 @multitable @columnfractions .4 .1 .1 .4
921 @item Supported Codec @tab Encoding @tab Decoding @tab Comments
922 @item MPEG-1 video @tab X @tab X
923 @item MPEG-2 video @tab X @tab X
924 @item MPEG-4 @tab X @tab X
925 @item MSMPEG4 V1 @tab X @tab X
926 @item MSMPEG4 V2 @tab X @tab X
927 @item MSMPEG4 V3 @tab X @tab X
928 @item WMV7 @tab X @tab X
929 @item WMV8 @tab X @tab X @tab not completely working
930 @item WMV9 @tab @tab X @tab not completely working
931 @item VC1 @tab @tab X
932 @item H.261 @tab X @tab X
933 @item H.263(+) @tab X @tab X @tab also known as RealVideo 1.0
934 @item H.264 @tab @tab X
935 @item RealVideo 1.0 @tab X @tab X
936 @item RealVideo 2.0 @tab X @tab X
937 @item MJPEG @tab X @tab X
938 @item lossless MJPEG @tab X @tab X
939 @item JPEG-LS @tab X @tab X @tab fourcc: MJLS, lossless and near-lossless is supported
940 @item Apple MJPEG-B @tab @tab X
941 @item Sunplus MJPEG @tab @tab X @tab fourcc: SP5X
942 @item DV @tab X @tab X
943 @item HuffYUV @tab X @tab X
944 @item FFmpeg Video 1 @tab X @tab X @tab experimental lossless codec (fourcc: FFV1)
945 @item FFmpeg Snow @tab X @tab X @tab experimental wavelet codec (fourcc: SNOW)
946 @item Asus v1 @tab X @tab X @tab fourcc: ASV1
947 @item Asus v2 @tab X @tab X @tab fourcc: ASV2
948 @item Creative YUV @tab @tab X @tab fourcc: CYUV
949 @item Sorenson Video 1 @tab X @tab X @tab fourcc: SVQ1
950 @item Sorenson Video 3 @tab @tab X @tab fourcc: SVQ3
951 @item On2 VP3 @tab @tab X @tab still experimental
952 @item On2 VP5 @tab @tab X @tab fourcc: VP50
953 @item On2 VP6 @tab @tab X @tab fourcc: VP62
954 @item Theora @tab @tab X @tab still experimental
955 @item Intel Indeo 3 @tab @tab X
956 @item FLV @tab X @tab X @tab Sorenson H.263 used in Flash
957 @item Flash Screen Video @tab @tab X @tab fourcc: FSV1
958 @item ATI VCR1 @tab @tab X @tab fourcc: VCR1
959 @item ATI VCR2 @tab @tab X @tab fourcc: VCR2
960 @item Cirrus Logic AccuPak @tab @tab X @tab fourcc: CLJR
961 @item 4X Video @tab @tab X @tab Used in certain computer games.
962 @item Sony Playstation MDEC @tab @tab X
963 @item Id RoQ @tab @tab X @tab Used in Quake III, Jedi Knight 2, other computer games.
964 @item Xan/WC3 @tab @tab X @tab Used in Wing Commander III .MVE files.
965 @item Interplay Video @tab @tab X @tab Used in Interplay .MVE files.
966 @item Apple Animation @tab @tab X @tab fourcc: 'rle '
967 @item Apple Graphics @tab @tab X @tab fourcc: 'smc '
968 @item Apple Video @tab @tab X @tab fourcc: rpza
969 @item Apple QuickDraw @tab @tab X @tab fourcc: qdrw
970 @item Cinepak @tab @tab X
971 @item Microsoft RLE @tab @tab X
972 @item Microsoft Video-1 @tab @tab X
973 @item Westwood VQA @tab @tab X
974 @item Id Cinematic Video @tab @tab X @tab Used in Quake II.
975 @item Planar RGB @tab @tab X @tab fourcc: 8BPS
976 @item FLIC video @tab @tab X
977 @item Duck TrueMotion v1 @tab @tab X @tab fourcc: DUCK
978 @item Duck TrueMotion v2 @tab @tab X @tab fourcc: TM20
979 @item VMD Video @tab @tab X @tab Used in Sierra VMD files.
980 @item MSZH @tab @tab X @tab Part of LCL
981 @item ZLIB @tab X @tab X @tab Part of LCL, encoder experimental
982 @item TechSmith Camtasia @tab @tab X @tab fourcc: TSCC
983 @item IBM Ultimotion @tab @tab X @tab fourcc: ULTI
984 @item Miro VideoXL @tab @tab X @tab fourcc: VIXL
985 @item QPEG @tab @tab X @tab fourccs: QPEG, Q1.0, Q1.1
986 @item LOCO @tab @tab X @tab
987 @item Winnov WNV1 @tab @tab X @tab
988 @item Autodesk Animator Studio Codec @tab @tab X @tab fourcc: AASC
989 @item Fraps FPS1 @tab @tab X @tab
990 @item CamStudio @tab @tab X @tab fourcc: CSCD
991 @item American Laser Games Video @tab @tab X @tab Used in games like Mad Dog McCree
992 @item ZMBV @tab @tab X @tab
993 @item AVS Video @tab @tab X @tab Video encoding used by the Creature Shock game.
994 @item Smacker Video @tab @tab X @tab Video encoding used in Smacker.
995 @item RTjpeg @tab @tab X @tab Video encoding used in NuppelVideo files.
996 @item KMVC @tab @tab X @tab Codec used in Worms games.
997 @item VMware Video @tab @tab X @tab Codec used in videos captured by VMware.
998 @item Cin Video @tab @tab X @tab Codec used in Delphine Software games.
999 @item Tiertex Seq Video @tab @tab X @tab Codec used in DOS CDROM FlashBack game.
1000 @end multitable
1002 @code{X} means that encoding (resp. decoding) is supported.
1004 @section Audio Codecs
1006 @multitable @columnfractions .4 .1 .1 .1 .7
1007 @item Supported Codec @tab Encoding @tab Decoding @tab Comments
1008 @item MPEG audio layer 2 @tab IX @tab IX
1009 @item MPEG audio layer 1/3 @tab IX @tab IX
1010 @tab MP3 encoding is supported through the external library LAME.
1011 @item AC3 @tab IX @tab IX
1012 @tab liba52 is used internally for decoding.
1013 @item Vorbis @tab X @tab X
1014 @item WMA V1/V2 @tab @tab X
1015 @item AAC @tab X @tab X
1016 @tab Supported through the external library libfaac/libfaad.
1017 @item Microsoft ADPCM @tab X @tab X
1018 @item MS IMA ADPCM @tab X @tab X
1019 @item QT IMA ADPCM @tab @tab X
1020 @item 4X IMA ADPCM @tab @tab X
1021 @item G.726 ADPCM @tab X @tab X
1022 @item Duck DK3 IMA ADPCM @tab @tab X
1023 @tab Used in some Sega Saturn console games.
1024 @item Duck DK4 IMA ADPCM @tab @tab X
1025 @tab Used in some Sega Saturn console games.
1026 @item Westwood Studios IMA ADPCM @tab @tab X
1027 @tab Used in Westwood Studios games like Command and Conquer.
1028 @item SMJPEG IMA ADPCM @tab @tab X
1029 @tab Used in certain Loki game ports.
1030 @item CD-ROM XA ADPCM @tab @tab X
1031 @item CRI ADX ADPCM @tab X @tab X
1032 @tab Used in Sega Dreamcast games.
1033 @item Electronic Arts ADPCM @tab @tab X
1034 @tab Used in various EA titles.
1035 @item Creative ADPCM @tab @tab X
1036 @tab 16 -> 4, 8 -> 4, 8 -> 3, 8 -> 2
1037 @item RA144 @tab @tab X
1038 @tab Real 14400 bit/s codec
1039 @item RA288 @tab @tab X
1040 @tab Real 28800 bit/s codec
1041 @item RADnet @tab X @tab IX
1042 @tab Real low bitrate AC3 codec, liba52 is used for decoding.
1043 @item AMR-NB @tab X @tab X
1044 @tab Supported through an external library.
1045 @item AMR-WB @tab X @tab X
1046 @tab Supported through an external library.
1047 @item DV audio @tab @tab X
1048 @item Id RoQ DPCM @tab @tab X
1049 @tab Used in Quake III, Jedi Knight 2, other computer games.
1050 @item Interplay MVE DPCM @tab @tab X
1051 @tab Used in various Interplay computer games.
1052 @item Xan DPCM @tab @tab X
1053 @tab Used in Origin's Wing Commander IV AVI files.
1054 @item Sierra Online DPCM @tab @tab X
1055 @tab Used in Sierra Online game audio files.
1056 @item Apple MACE 3 @tab @tab X
1057 @item Apple MACE 6 @tab @tab X
1058 @item FLAC lossless audio @tab @tab X
1059 @item Shorten lossless audio @tab @tab X
1060 @item Apple lossless audio @tab @tab X
1061 @tab QuickTime fourcc 'alac'
1062 @item FFmpeg Sonic @tab X @tab X
1063 @tab experimental lossy/lossless codec
1064 @item Qdesign QDM2 @tab @tab X
1065 @tab there are still some distortions
1066 @item Real COOK @tab @tab X
1067 @tab All versions except 5.1 are supported
1068 @item DSP Group TrueSpeech @tab @tab X
1069 @item True Audio (TTA) @tab @tab X
1070 @item Smacker Audio @tab @tab X
1071 @item WavPack Audio @tab @tab X
1072 @item Cin Audio @tab @tab X
1073 @tab Codec used in Delphine Software games.
1074 @item Intel Music Coder @tab @tab X
1075 @end multitable
1077 @code{X} means that encoding (resp. decoding) is supported.
1079 @code{I} means that an integer-only version is available, too (ensures high
1080 performance on systems without hardware floating point support).
1082 @chapter Platform Specific information
1084 @section Linux
1086 FFmpeg should be compiled with at least GCC 2.95.3. GCC 3.2 is the
1087 preferred compiler now for FFmpeg. All future optimizations will depend on
1088 features only found in GCC 3.2.
1090 @section BSD
1092 BSD make will not build FFmpeg, you need to install and use GNU Make
1093 (@file{gmake}).
1095 @section Windows
1097 @subsection Native Windows compilation
1099 @itemize
1100 @item Install the current versions of MSYS and MinGW from
1101 @url{http://www.mingw.org/}. You can find detailed installation
1102 instructions in the download section and the FAQ.
1104 @item If you want to test the FFplay, also download
1105 the MinGW development library of SDL 1.2.x
1106 (@file{SDL-devel-1.2.x-mingw32.tar.gz}) from
1107 @url{http://www.libsdl.org}. Unpack it in a temporary directory, and
1108 unpack the archive @file{i386-mingw32msvc.tar.gz} in the MinGW tool
1109 directory. Edit the @file{sdl-config} script so that it gives the
1110 correct SDL directory when invoked.
1112 @item Extract the current version of FFmpeg.
1114 @item Start the MSYS shell (file @file{msys.bat}).
1116 @item Change to the FFmpeg directory and follow
1117 the instructions of how to compile FFmpeg (file
1118 @file{INSTALL}). Usually, launching @file{./configure} and @file{make}
1119 suffices. If you have problems using SDL, verify that
1120 @file{sdl-config} can be launched from the MSYS command line.
1122 @item You can install FFmpeg in @file{Program Files/FFmpeg} by typing
1123 @file{make install}. Don't forget to copy @file{SDL.dll} to the place
1124 you launch @file{ffplay} from.
1126 @end itemize
1128 Notes:
1129 @itemize
1131 @item The target @file{make wininstaller} can be used to create a
1132 Nullsoft based Windows installer for FFmpeg and FFplay. @file{SDL.dll}
1133 must be copied to the FFmpeg directory in order to build the
1134 installer.
1136 @item By using @code{./configure --enable-shared} when configuring FFmpeg,
1137 you can build @file{avcodec.dll} and @file{avformat.dll}. With
1138 @code{make install} you install the FFmpeg DLLs and the associated
1139 headers in @file{Program Files/FFmpeg}.
1141 @item Visual C++ compatibility: If you used @code{./configure --enable-shared}
1142 when configuring FFmpeg, FFmpeg tries to use the Microsoft Visual
1143 C++ @code{lib} tool to build @code{avcodec.lib} and
1144 @code{avformat.lib}. With these libraries you can link your Visual C++
1145 code directly with the FFmpeg DLLs (see below).
1147 @end itemize
1149 @subsection Visual C++ compatibility
1151 FFmpeg will not compile under Visual C++ -- and it has too many
1152 dependencies on the GCC compiler to make a port viable. However,
1153 if you want to use the FFmpeg libraries in your own applications,
1154 you can still compile those applications using Visual C++. An
1155 important restriction to this is that you have to use the
1156 dynamically linked versions of the FFmpeg libraries (i.e. the
1157 DLLs), and you have to make sure that Visual-C++-compatible
1158 import libraries are created during the FFmpeg build process.
1160 This description of how to use the FFmpeg libraries with Visual C++ is
1161 based on Visual C++ 2005 Express Edition Beta 2. If you have a different
1162 version, you might have to modify the procedures slightly.
1164 Here are the step-by-step instructions for building the FFmpeg libraries
1165 so they can be used with Visual C++:
1167 @enumerate
1169 @item Install Visual C++ (if you haven't done so already).
1171 @item Install MinGW and MSYS as described above.
1173 @item Add a call to @file{vcvars32.bat} (which sets up the environment
1174 variables for the Visual C++ tools) as the first line of
1175 @file{msys.bat}. The standard location for @file{vcvars32.bat} is
1176 @file{C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat},
1177 and the standard location for @file{msys.bat} is
1178 @file{C:\msys\1.0\msys.bat}. If this corresponds to your setup, add the
1179 following line as the first line of @file{msys.bat}:
1181 @code{call "C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat"}
1183 @item Start the MSYS shell (file @file{msys.bat}) and type @code{link.exe}.
1184 If you get a help message with the command line options of @code{link.exe},
1185 this means your environment variables are set up correctly, the
1186 Microsoft linker is on the path and will be used by FFmpeg to
1187 create Visual-C++-compatible import libraries.
1189 @item Extract the current version of FFmpeg and change to the FFmpeg directory.
1191 @item Type the command
1192 @code{./configure --enable-shared --disable-static --enable-memalign-hack}
1193 to configure and, if that didn't produce any errors,
1194 type @code{make} to build FFmpeg.
1196 @item The subdirectories @file{libavformat}, @file{libavcodec}, and
1197 @file{libavutil} should now contain the files @file{avformat.dll},
1198 @file{avformat.lib}, @file{avcodec.dll}, @file{avcodec.lib},
1199 @file{avutil.dll}, and @file{avutil.lib}, respectively. Copy the three
1200 DLLs to your System32 directory (typically @file{C:\Windows\System32}).
1202 @end enumerate
1204 And here is how to use these libraries with Visual C++:
1206 @enumerate
1208 @item Create a new console application ("File / New / Project") and then
1209 select "Win32 Console Application". On the appropriate page of the
1210 Application Wizard, uncheck the "Precompiled headers" option.
1212 @item Write the source code for your application, or, for testing, just
1213 copy the code from an existing sample application into the source file
1214 that Visual C++ has already created for you. (Note that your source
1215 filehas to have a @code{.cpp} extension; otherwise, Visual C++ won't
1216 compile the FFmpeg headers correctly because in C mode, it doesn't
1217 recognize the @code{inline} keyword.) For example, you can copy
1218 @file{output_example.c} from the FFmpeg distribution (but you will
1219 have to make minor modifications so the code will compile under
1220 C++, see below).
1222 @item Open the "Project / Properties" dialog box. In the "Configuration"
1223 combo box, select "All Configurations" so that the changes you make will
1224 affect both debug and release builds. In the tree view on the left hand
1225 side, select "C/C++ / General", then edit the "Additional Include
1226 Directories" setting to contain the complete paths to the
1227 @file{libavformat}, @file{libavcodec}, and @file{libavutil}
1228 subdirectories of your FFmpeg directory. Note that the directories have
1229 to be separated using semicolons. Now select "Linker / General" from the
1230 tree view and edit the "Additional Library Directories" setting to
1231 contain the same three directories.
1233 @item Still in the "Project / Properties" dialog box, select "Linker / Input"
1234 from the tree view, then add the files @file{avformat.lib},
1235 @file{avcodec.lib}, and @file{avutil.lib} to the end of the "Additional
1236 Dependencies". Note that the names of the libraries have to be separated
1237 using spaces.
1239 @item Now, select "C/C++ / Code Generation" from the tree view. Select
1240 "Debug" in the "Configuration" combo box. Make sure that "Runtime
1241 Library" is set to "Multi-threaded Debug DLL". Then, select "Release" in
1242 the "Configuration" combo box and make sure that "Runtime Library" is
1243 set to "Multi-threaded DLL".
1245 @item Click "OK" to close the "Project / Properties" dialog box and build
1246 the application. Hopefully, it should compile and run cleanly. If you
1247 used @file{output_example.c} as your sample application, you will get a
1248 few compiler errors, but they are easy to fix. The first type of error
1249 occurs because Visual C++ doesn't allow an @code{int} to be converted to
1250 an @code{enum} without a cast. To solve the problem, insert the required
1251 casts (this error occurs once for a @code{CodecID} and once for a
1252 @code{CodecType}). The second type of error occurs because C++ requires
1253 the return value of @code{malloc} to be cast to the exact type of the
1254 pointer it is being assigned to. Visual C++ will complain that, for
1255 example, @code{(void *)} is being assigned to @code{(uint8_t *)} without
1256 an explicit cast. So insert an explicit cast in these places to silence
1257 the compiler. The third type of error occurs because the @code{snprintf}
1258 library function is called @code{_snprintf} under Visual C++. So just
1259 add an underscore to fix the problem. With these changes,
1260 @file{output_example.c} should compile under Visual C++, and the
1261 resulting executable should produce valid video files.
1263 @end enumerate
1265 @subsection Cross compilation for Windows with Linux
1267 You must use the MinGW cross compilation tools available at
1268 @url{http://www.mingw.org/}.
1270 Then configure FFmpeg with the following options:
1271 @example
1272 ./configure --enable-mingw32 --cross-prefix=i386-mingw32msvc-
1273 @end example
1274 (you can change the cross-prefix according to the prefix chosen for the
1275 MinGW tools).
1277 Then you can easily test FFmpeg with Wine
1278 (@url{http://www.winehq.com/}).
1280 @subsection Compilation under Cygwin
1282 Cygwin works very much like Unix.
1284 Just install your Cygwin with all the "Base" packages, plus the
1285 following "Devel" ones:
1286 @example
1287 binutils, gcc-core, make, subversion
1288 @end example
1290 Do not install binutils-20060709-1 (they are buggy on shared builds);
1291 use binutils-20050610-1 instead.
1293 Then run
1295 @example
1296 ./configure --enable-static --disable-shared
1297 @end example
1299 to make a static build or
1301 @example
1302 ./configure --enable-shared --disable-static
1303 @end example
1305 to build shared libraries.
1307 If you want to build FFmpeg with additional libraries, download Cygwin
1308 "Devel" packages for Ogg and Vorbis from any Cygwin packages repository
1309 and/or SDL, xvid, faac, faad2 packages from Cygwin Ports,
1310 (@url{http://cygwinports.dotsrc.org/}).
1312 @subsection Crosscompilation for Windows under Cygwin
1314 With Cygwin you can create Windows binaries that don't need the cygwin1.dll.
1316 Just install your Cygwin as explained before, plus these additional
1317 "Devel" packages:
1318 @example
1319 gcc-mingw-core, mingw-runtime, mingw-zlib
1320 @end example
1322 and add some special flags to your configure invocation.
1324 For a static build run
1325 @example
1326 ./configure --enable-mingw32 --enable-memalign-hack --enable-static --disable-shared --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
1327 @end example
1329 and for a build with shared libraries
1330 @example
1331 ./configure --enable-mingw32 --enable-memalign-hack --enable-shared --disable-static --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
1332 @end example
1334 @section BeOS
1336 The configure script should guess the configuration itself.
1337 Networking support is currently not finished.
1338 errno issues fixed by Andrew Bachmann.
1340 Old stuff:
1342 Fran├žois Revol - revol at free dot fr - April 2002
1344 The configure script should guess the configuration itself,
1345 however I still didn't test building on the net_server version of BeOS.
1347 FFserver is broken (needs poll() implementation).
1349 There are still issues with errno codes, which are negative in BeOS, and
1350 that FFmpeg negates when returning. This ends up turning errors into
1351 valid results, then crashes.
1352 (To be fixed)
1354 @chapter Developers Guide
1356 @section API
1357 @itemize @bullet
1358 @item libavcodec is the library containing the codecs (both encoding and
1359 decoding). Look at @file{libavcodec/apiexample.c} to see how to use it.
1361 @item libavformat is the library containing the file format handling (mux and
1362 demux code for several formats). Look at @file{ffplay.c} to use it in a
1363 player. See @file{output_example.c} to use it to generate audio or video
1364 streams.
1366 @end itemize
1368 @section Integrating libavcodec or libavformat in your program
1370 You can integrate all the source code of the libraries to link them
1371 statically to avoid any version problem. All you need is to provide a
1372 'config.mak' and a 'config.h' in the parent directory. See the defines
1373 generated by ./configure to understand what is needed.
1375 You can use libavcodec or libavformat in your commercial program, but
1376 @emph{any patch you make must be published}. The best way to proceed is
1377 to send your patches to the FFmpeg mailing list.
1379 @node Coding Rules
1380 @section Coding Rules
1382 FFmpeg is programmed in the ISO C90 language with a few additional
1383 features from ISO C99, namely:
1384 @itemize @bullet
1385 @item
1386 the @samp{inline} keyword;
1387 @item
1388 @samp{//} comments;
1389 @item
1390 designated struct initializers (@samp{struct s x = @{ .i = 17 @};})
1391 @item
1392 compound literals (@samp{x = (struct s) @{ 17, 23 @};})
1393 @end itemize
1395 These features are supported by all compilers we care about, so we won't
1396 accept patches to remove their use unless they absolutely don't impair
1397 clarity and performance.
1399 All code must compile with GCC 2.95 and GCC 3.3. Currently, FFmpeg also
1400 compiles with several other compilers, such as the Compaq ccc compiler
1401 or Sun Studio 9, and we would like to keep it that way unless it would
1402 be exceedingly involved. To ensure compatibility, please don't use any
1403 additional C99 features or GCC extensions. Especially watch out for:
1404 @itemize @bullet
1405 @item
1406 mixing statements and declarations;
1407 @item
1408 @samp{long long} (use @samp{int64_t} instead);
1409 @item
1410 @samp{__attribute__} not protected by @samp{#ifdef __GNUC__} or similar;
1411 @item
1412 GCC statement expressions (@samp{(x = (@{ int y = 4; y; @})}).
1413 @end itemize
1415 Indent size is 4.
1416 The presentation is the one specified by 'indent -i4 -kr -nut'.
1417 The TAB character is forbidden outside of Makefiles as is any
1418 form of trailing whitespace. Commits containing either will be
1419 rejected by the Subversion repository.
1421 Main priority in FFmpeg is simplicity and small code size (=less
1422 bugs).
1424 Comments: Use the JavaDoc/Doxygen
1425 format (see examples below) so that code documentation
1426 can be generated automatically. All nontrivial functions should have a comment
1427 above them explaining what the function does, even if it's just one sentence.
1428 All structures and their member variables should be documented, too.
1429 @example
1430 /**
1431 * @@file mpeg.c
1432 * MPEG codec.
1433 * @@author ...
1434 */
1436 /**
1437 * Summary sentence.
1438 * more text ...
1439 * ...
1440 */
1441 typedef struct Foobar@{
1442 int var1; /**< var1 description */
1443 int var2; ///< var2 description
1444 /** var3 description */
1445 int var3;
1446 @} Foobar;
1448 /**
1449 * Summary sentence.
1450 * more text ...
1451 * ...
1452 * @@param my_parameter description of my_parameter
1453 * @@return return value description
1454 */
1455 int myfunc(int my_parameter)
1456 ...
1457 @end example
1459 fprintf and printf are forbidden in libavformat and libavcodec,
1460 please use av_log() instead.
1462 @section Development Policy
1464 @enumerate
1465 @item
1466 You must not commit code which breaks FFmpeg! (Meaning unfinished but
1467 enabled code which breaks compilation or compiles but does not work or
1468 breaks the regression tests)
1469 You can commit unfinished stuff (for testing etc), but it must be disabled
1470 (#ifdef etc) by default so it does not interfere with other developers'
1471 work.
1472 @item
1473 You don't have to over-test things. If it works for you, and you think it
1474 should work for others, then commit. If your code has problems
1475 (portability, triggers compiler bugs, unusual environment etc) they will be
1476 reported and eventually fixed.
1477 @item
1478 Do not commit unrelated changes together, split them into self-contained
1479 pieces.
1480 @item
1481 Do not change behavior of the program (renaming options etc) without
1482 first discussing it on the ffmpeg-devel mailing list. Do not remove
1483 functionality from the code. Just improve!
1485 Note: Redundant code can be removed.
1486 @item
1487 Do not commit changes to the build system (Makefiles, configure script)
1488 which change behavior, defaults etc, without asking first. The same
1489 applies to compiler warning fixes, trivial looking fixes and to code
1490 maintained by other developers. We usually have a reason for doing things
1491 the way we do. Send your changes as patches to the ffmpeg-devel mailing
1492 list, and if the code maintainers say OK, you may commit. This does not
1493 apply to files you wrote and/or maintain.
1494 @item
1495 We refuse source indentation and other cosmetic changes if they are mixed
1496 with functional changes, such commits will be rejected and removed. Every
1497 developer has his own indentation style, you should not change it. Of course
1498 if you (re)write something, you can use your own style, even though we would
1499 prefer if the indentation throughout FFmpeg was consistent (Many projects
1500 force a given indentation style - we don't.). If you really need to make
1501 indentation changes (try to avoid this), separate them strictly from real
1502 changes.
1504 NOTE: If you had to put if()@{ .. @} over a large (> 5 lines) chunk of code,
1505 then either do NOT change the indentation of the inner part within (don't
1506 move it to the right)! or do so in a separate commit
1507 @item
1508 Always fill out the commit log message. Describe in a few lines what you
1509 changed and why. You can refer to mailing list postings if you fix a
1510 particular bug. Comments such as "fixed!" or "Changed it." are unacceptable.
1511 @item
1512 If you apply a patch by someone else, include the name and email address in
1513 the log message. Since the ffmpeg-cvslog mailing list is publicly
1514 archived you should add some SPAM protection to the email address. Send an
1515 answer to ffmpeg-devel (or wherever you got the patch from) saying that
1516 you applied the patch.
1517 @item
1518 Do NOT commit to code actively maintained by others without permission.
1519 Send a patch to ffmpeg-devel instead. If noone answers within a reasonable
1520 timeframe (12h for build failures and security fixes, 3 days small changes,
1521 1 week for big patches) then commit your patch if you think it's OK.
1522 Also note, the maintainer can simply ask for more time to review!
1523 @item
1524 Subscribe to the ffmpeg-cvslog mailing list. The diffs of all commits
1525 are sent there and reviewed by all the other developers. Bugs and possible
1526 improvements or general questions regarding commits are discussed there. We
1527 expect you to react if problems with your code are uncovered.
1528 @item
1529 Update the documentation if you change behavior or add features. If you are
1530 unsure how best to do this, send a patch to ffmpeg-devel, the documentation
1531 maintainer(s) will review and commit your stuff.
1532 @item
1533 Never write to unallocated memory, never write over the end of arrays,
1534 always check values read from some untrusted source before using them
1535 as array index or other risky things.
1536 @item
1537 Remember to check if you need to bump versions for the specific libav
1538 parts (libavutil, libavcodec, libavformat) you are changing. You need
1539 to change the version integer and the version string.
1540 Incrementing the first component means no backward compatibility to
1541 previous versions (e.g. removal of a function from the public API).
1542 Incrementing the second component means backward compatible change
1543 (e.g. addition of a function to the public API).
1544 Incrementing the third component means a noteworthy binary compatible
1545 change (e.g. encoder bug fix that matters for the decoder).
1546 @item
1547 If you add a new codec, remember to update the changelog, add it to
1548 the supported codecs table in the documentation and bump the second
1549 component of the @file{libavcodec} version number appropriately. If
1550 it has a fourcc, add it to @file{libavformat/avienc.c}, even if it
1551 is only a decoder.
1552 @end enumerate
1554 We think our rules are not too hard. If you have comments, contact us.
1556 Note, these rules are mostly borrowed from the MPlayer project.
1558 @section Submitting patches
1560 First, (@pxref{Coding Rules}) above if you didn't yet.
1562 When you submit your patch, try to send a unified diff (diff '-up'
1563 option). I cannot read other diffs :-)
1565 Also please do not submit patches which contain several unrelated changes.
1566 Split them into individual self-contained patches; this makes reviewing
1567 them much easier.
1569 Run the regression tests before submitting a patch so that you can
1570 verify that there are no big problems.
1572 Patches should be posted as base64 encoded attachments (or any other
1573 encoding which ensures that the patch won't be trashed during
1574 transmission) to the ffmpeg-devel mailing list, see
1575 @url{http://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel}
1577 It also helps quite a bit if you tell us what the patch does (for example
1578 'replaces lrint by lrintf'), and why (for example '*BSD isn't C99 compliant
1579 and has no lrint()')
1581 We reply to all submitted patches and either apply or reject with some
1582 explanation why, but sometimes we are quite busy so it can take a week or two.
1584 @section Regression tests
1586 Before submitting a patch (or committing to the repository), you should at least
1587 test that you did not break anything.
1589 The regression tests build a synthetic video stream and a synthetic
1590 audio stream. These are then encoded and decoded with all codecs or
1591 formats. The CRC (or MD5) of each generated file is recorded in a
1592 result file. A 'diff' is launched to compare the reference results and
1593 the result file.
1595 The regression tests then go on to test the FFserver code with a
1596 limited set of streams. It is important that this step runs correctly
1597 as well.
1599 Run 'make test' to test all the codecs and formats.
1601 Run 'make fulltest' to test all the codecs, formats and FFserver.
1603 [Of course, some patches may change the results of the regression tests. In
1604 this case, the reference results of the regression tests shall be modified
1605 accordingly].
1607 @bye