doc update for Shorten codec
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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 the parameters, when
18 possible. You have usually to give only the target bitrate you want.
20 FFmpeg can also convert from any sample rate to any other, and resize
21 video on the fly with a high quality polyphase filter.
23 @chapter Quick Start
25 @c man begin EXAMPLES
26 @section Video and Audio grabbing
28 FFmpeg can use a video4linux compatible video source and any Open Sound
29 System audio source:
31 @example
32 ffmpeg /tmp/out.mpg
33 @end example
35 Note that you must activate the right video source and channel before
36 launching ffmpeg. You can use any TV viewer such as xawtv
37 (@url{}) by Gerd Knorr which I find very
38 good. You must also set correctly the audio recording levels with a
39 standard mixer.
41 @section Video and Audio file format conversion
43 * ffmpeg can use any supported file format and protocol as input:
45 Examples:
47 * You can input from YUV files:
49 @example
50 ffmpeg -i /tmp/test%d.Y /tmp/out.mpg
51 @end example
53 It will use the files:
54 @example
55 /tmp/test0.Y, /tmp/test0.U, /tmp/test0.V,
56 /tmp/test1.Y, /tmp/test1.U, /tmp/test1.V, etc...
57 @end example
59 The Y files use twice the resolution of the U and V files. They are
60 raw files, without header. They can be generated by all decent video
61 decoders. You must specify the size of the image with the @option{-s} option
62 if ffmpeg cannot guess it.
64 * You can input from a RAW YUV420P file:
66 @example
67 ffmpeg -i /tmp/test.yuv /tmp/out.avi
68 @end example
70 The RAW YUV420P is a file containing RAW YUV planar, for each frame first
71 come the Y plane followed by U and V planes, which are half vertical and
72 horizontal resolution.
74 * You can output to a RAW YUV420P file:
76 @example
77 ffmpeg -i mydivx.avi -o hugefile.yuv
78 @end example
80 * You can set several input files and output files:
82 @example
83 ffmpeg -i /tmp/a.wav -s 640x480 -i /tmp/a.yuv /tmp/a.mpg
84 @end example
86 Convert the audio file a.wav and the raw yuv video file a.yuv
87 to mpeg file a.mpg
89 * You can also do audio and video conversions at the same time:
91 @example
92 ffmpeg -i /tmp/a.wav -ar 22050 /tmp/a.mp2
93 @end example
95 Convert the sample rate of a.wav to 22050 Hz and encode it to MPEG audio.
97 * You can encode to several formats at the same time and define a
98 mapping from input stream to output streams:
100 @example
101 ffmpeg -i /tmp/a.wav -ab 64 /tmp/a.mp2 -ab 128 /tmp/b.mp2 -map 0:0 -map 0:0
102 @end example
104 Convert a.wav to a.mp2 at 64 kbits and b.mp2 at 128 kbits. '-map
105 file:index' specify which input stream is used for each output
106 stream, in the order of the definition of output streams.
108 * You can transcode decrypted VOBs
110 @example
111 ffmpeg -i snatch_1.vob -f avi -vcodec mpeg4 -b 800 -g 300 -bf 2 -acodec mp3 -ab 128 snatch.avi
112 @end example
114 This is a typical DVD ripper example, input from a VOB file, output
115 to an AVI file with MPEG-4 video and MP3 audio, note that in this
116 command we use B frames so the MPEG-4 stream is DivX5 compatible, GOP
117 size is 300 that means an INTRA frame every 10 seconds for 29.97 fps
118 input video. Also the audio stream is MP3 encoded so you need LAME
119 support which is enabled using @code{--enable-mp3lame} when
120 configuring. The mapping is particularly useful for DVD transcoding
121 to get the desired audio language.
123 NOTE: to see the supported input formats, use @code{ffmpeg -formats}.
124 @c man end
126 @chapter Invocation
128 @section Syntax
130 The generic syntax is:
132 @example
133 @c man begin SYNOPSIS
134 ffmpeg [[infile options][@option{-i} @var{infile}]]... @{[outfile options] @var{outfile}@}...
135 @c man end
136 @end example
137 @c man begin DESCRIPTION
138 If no input file is given, audio/video grabbing is done.
140 As a general rule, options are applied to the next specified
141 file. For example, if you give the @option{-b 64} option, it sets the video
142 bitrate of the next file. Format option may be needed for raw input
143 files.
145 By default, ffmpeg tries to convert as losslessly as possible: it
146 uses the same audio and video parameter for the outputs as the one
147 specified for the inputs.
148 @c man end
150 @c man begin OPTIONS
151 @section Main options
153 @table @option
154 @item -L
155 show license
157 @item -h
158 show help
160 @item -formats
161 show available formats, codecs, protocols, ...
163 @item -f fmt
164 force format
166 @item -i filename
167 input file name
169 @item -y
170 overwrite output files
172 @item -t duration
173 set the recording time in seconds. @code{hh:mm:ss[.xxx]} syntax is also
174 supported.
176 @item -ss position
177 seek to given time position. @code{hh:mm:ss[.xxx]} syntax is also
178 supported.
180 @item -title string
181 set the title
183 @item -author string
184 set the author
186 @item -copyright string
187 set the copyright
189 @item -comment string
190 set the comment
192 @item -target type
193 specify target file type ("vcd", "svcd", "dvd", "dv", "pal-vcd", "ntsc-svcd", ... ). All the format
194 options (bitrate, codecs, buffer sizes) are automatically set by this
195 option. You can just type:
197 @example
198 ffmpeg -i myfile.avi -target vcd /tmp/vcd.mpg
199 @end example
201 Nevertheless you can specify additional options as long as you know they do not compromise the
202 standard, as in:
204 @example
205 ffmpeg -i myfile.avi -target vcd -bf 2 /tmp/vcd.mpg
206 @end example
208 @item -hq
209 activate high quality settings
211 @item -itsoffset offset
212 set the input time offset in seconds. @code{[-]hh:mm:ss[.xxx]} syntax
213 is also supported. This option affects all the input files that
214 follow it. The offset is added to the input files' timestamps;
215 specifying a positive offset means that the corresponding streams are
216 delayed by 'offset' seconds.
218 @end table
220 @section Video Options
222 @table @option
223 @item -b bitrate
224 set the video bitrate in kbit/s (default = 200 kb/s)
225 @item -r fps
226 set frame rate (default = 25)
227 @item -s size
228 set frame size. The format is @samp{WxH} (default 160x128). The
229 following abbreviations are recognized:
230 @table @samp
231 @item sqcif
232 128x96
233 @item qcif
234 176x144
235 @item cif
236 352x288
237 @item 4cif
238 704x576
239 @end table
241 @item -aspect aspect
242 set aspect ratio (4:3, 16:9 or 1.3333, 1.7777)
243 @item -croptop size
244 set top crop band size (in pixels)
245 @item -cropbottom size
246 set bottom crop band size (in pixels)
247 @item -cropleft size
248 set left crop band size (in pixels)
249 @item -cropright size
250 set right crop band size (in pixels)
251 @item -padtop size
252 set top pad band size (in pixels)
253 @item -padbottom size
254 set bottom pad band size (in pixels)
255 @item -padleft size
256 set left pad band size (in pixels)
257 @item -padright size
258 set right pad band size (in pixels)
259 @item -padcolor (hex color)
260 set color of padded bands. The value for pad color is expressed
261 as a six digit hexidecimal number where the first two digits represent red,
262 middle two digits green and last two digits blue. Defaults to 000000 (black)
263 @item -vn
264 disable video recording
265 @item -bt tolerance
266 set video bitrate tolerance (in kbit/s)
267 @item -maxrate bitrate
268 set max video bitrate tolerance (in kbit/s)
269 @item -minrate bitrate
270 set min video bitrate tolerance (in kbit/s)
271 @item -bufsize size
272 set ratecontrol buffere size (in kbit)
273 @item -vcodec codec
274 force video codec to @var{codec}. Use the @code{copy} special value to
275 tell that the raw codec data must be copied as is.
276 @item -sameq
277 use same video quality as source (implies VBR)
279 @item -pass n
280 select the pass number (1 or 2). It is useful to do two pass
281 encoding. The statistics of the video are recorded in the first pass and
282 the video at the exact requested bit rate is generated in the second
283 pass.
285 @item -passlogfile file
286 select two pass log file name to @var{file}.
288 @end table
290 @section Advanced Video Options
292 @table @option
293 @item -g gop_size
294 set the group of picture size
295 @item -intra
296 use only intra frames
297 @item -qscale q
298 use fixed video quantiser scale (VBR)
299 @item -qmin q
300 min video quantiser scale (VBR)
301 @item -qmax q
302 max video quantiser scale (VBR)
303 @item -qdiff q
304 max difference between the quantiser scale (VBR)
305 @item -qblur blur
306 video quantiser scale blur (VBR)
307 @item -qcomp compression
308 video quantiser scale compression (VBR)
310 @item -rc_init_cplx complexity
311 initial complexity for 1-pass encoding
312 @item -b_qfactor factor
313 qp factor between p and b frames
314 @item -i_qfactor factor
315 qp factor between p and i frames
316 @item -b_qoffset offset
317 qp offset between p and b frames
318 @item -i_qoffset offset
319 qp offset between p and i frames
320 @item -rc_eq equation
321 set rate control equation (@pxref{FFmpeg formula
322 evaluator}). Default is @code{tex^qComp}.
323 @item -rc_override override
324 rate control override for specific intervals
325 @item -me method
326 set motion estimation method to @var{method}. Available methods are
327 (from lower to best quality):
328 @table @samp
329 @item zero
330 Try just the (0, 0) vector.
331 @item phods
332 @item log
333 @item x1
334 @item epzs
335 (default method)
336 @item full
337 exhaustive search (slow and marginally better than epzs)
338 @end table
340 @item -dct_algo algo
341 set dct algorithm to @var{algo}. Available values are:
342 @table @samp
343 @item 0
344 FF_DCT_AUTO (default)
345 @item 1
347 @item 2
349 @item 3
351 @item 4
353 @item 5
355 @end table
357 @item -idct_algo algo
358 set idct algorithm to @var{algo}. Available values are:
359 @table @samp
360 @item 0
361 FF_IDCT_AUTO (default)
362 @item 1
364 @item 2
366 @item 3
368 @item 4
370 @item 5
372 @item 6
374 @item 7
376 @item 8
378 @item 9
380 @item 10
382 @end table
384 @item -er n
385 set error resilience to @var{n}.
386 @table @samp
387 @item 1
388 FF_ER_CAREFULL (default)
389 @item 2
391 @item 3
393 @item 4
395 @end table
397 @item -ec bit_mask
398 set error concealment to @var{bit_mask}. @var{bit_mask} is a bit mask of
399 the following values:
400 @table @samp
401 @item 1
402 FF_EC_GUESS_MVS (default=enabled)
403 @item 2
404 FF_EC_DEBLOCK (default=enabled)
405 @end table
407 @item -bf frames
408 use 'frames' B frames (supported for MPEG-1, MPEG-2 and MPEG-4)
409 @item -mbd mode
410 macroblock decision
411 @table @samp
412 @item 0
413 FF_MB_DECISION_SIMPLE: use mb_cmp (cannot change it yet in ffmpeg)
414 @item 1
415 FF_MB_DECISION_BITS: chooses the one which needs the fewest bits
416 @item 2
417 FF_MB_DECISION_RD: rate distoration
418 @end table
420 @item -4mv
421 use four motion vector by macroblock (only MPEG-4)
422 @item -part
423 use data partitioning (only MPEG-4)
424 @item -bug param
425 workaround not auto detected encoder bugs
426 @item -strict strictness
427 how strictly to follow the standarts
428 @item -aic
429 enable Advanced intra coding (h263+)
430 @item -umv
431 enable Unlimited Motion Vector (h263+)
433 @item -deinterlace
434 deinterlace pictures
435 @item -interlace
436 force interlacing support in encoder (only MPEG-2 and MPEG-4). Use this option
437 if your input file is interlaced and if you want to keep the interlaced
438 format for minimum losses. The alternative is to deinterlace the input
439 stream with @option{-deinterlace}, but deinterlacing introduces more
440 losses.
441 @item -psnr
442 calculate PSNR of compressed frames
443 @item -vstats
444 dump video coding statistics to @file{vstats_HHMMSS.log}.
445 @item -vhook module
446 insert video processing @var{module}. @var{module} contains the module
447 name and its parameters separated by spaces.
448 @end table
450 @section Audio Options
452 @table @option
453 @item -ar freq
454 set the audio sampling freq (default = 44100 Hz)
455 @item -ab bitrate
456 set the audio bitrate in kbit/s (default = 64)
457 @item -ac channels
458 set the number of audio channels (default = 1)
459 @item -an
460 disable audio recording
461 @item -acodec codec
462 force audio codec to @var{codec}. Use the @code{copy} special value to
463 tell that the raw codec data must be copied as is.
464 @end table
466 @section Audio/Video grab options
468 @table @option
469 @item -vd device
470 set video grab device (e.g. @file{/dev/video0})
471 @item -vc channel
472 set video grab channel (DV1394 only)
473 @item -tvstd standard
474 set television standard (NTSC, PAL (SECAM))
475 @item -dv1394
476 set DV1394 grab
477 @item -ad device
478 set audio device (e.g. @file{/dev/dsp})
479 @end table
481 @section Advanced options
483 @table @option
484 @item -map file:stream
485 set input stream mapping
486 @item -debug
487 print specific debug info
488 @item -benchmark
489 add timings for benchmarking
490 @item -hex
491 dump each input packet
492 @item -bitexact
493 only use bit exact algorithms (for codec testing)
494 @item -ps size
495 set packet size in bits
496 @item -re
497 read input at native frame rate. Mainly used to simulate a grab device.
498 @item -loop
499 loop over the input stream. Currently it works only for image
500 streams. This option is used for ffserver automatic testing.
501 @end table
503 @node FFmpeg formula evaluator
504 @section FFmpeg formula evaluator
506 When evaluating a rate control string, FFmpeg uses an internal formula
507 evaluator.
509 The following binary operators are available: @code{+}, @code{-},
510 @code{*}, @code{/}, @code{^}.
512 The following unary operators are available: @code{+}, @code{-},
513 @code{(...)}.
515 The following functions are available:
516 @table @var
517 @item sinh(x)
518 @item cosh(x)
519 @item tanh(x)
520 @item sin(x)
521 @item cos(x)
522 @item tan(x)
523 @item exp(x)
524 @item log(x)
525 @item squish(x)
526 @item gauss(x)
527 @item abs(x)
528 @item max(x, y)
529 @item min(x, y)
530 @item gt(x, y)
531 @item lt(x, y)
532 @item eq(x, y)
533 @item bits2qp(bits)
534 @item qp2bits(qp)
535 @end table
537 The following constants are available:
538 @table @var
539 @item PI
540 @item E
541 @item iTex
542 @item pTex
543 @item tex
544 @item mv
545 @item fCode
546 @item iCount
547 @item mcVar
548 @item var
549 @item isI
550 @item isP
551 @item isB
552 @item avgQP
553 @item qComp
554 @item avgIITex
555 @item avgPITex
556 @item avgPPTex
557 @item avgBPTex
558 @item avgTex
559 @end table
561 @c man end
563 @ignore
565 @setfilename ffmpeg
566 @settitle FFmpeg video converter
568 @c man begin SEEALSO
569 ffserver(1), ffplay(1) and the html documentation of @file{ffmpeg}.
570 @c man end
572 @c man begin AUTHOR
573 Fabrice Bellard
574 @c man end
576 @end ignore
578 @section Protocols
580 The filename can be @file{-} to read from the standard input or to write
581 to the standard output.
583 ffmpeg handles also many protocols specified with the URL syntax.
585 Use 'ffmpeg -formats' to have a list of the supported protocols.
587 The protocol @code{http:} is currently used only to communicate with
588 ffserver (see the ffserver documentation). When ffmpeg will be a
589 video player it will also be used for streaming :-)
591 @chapter Tips
593 @itemize
594 @item For streaming at very low bit rate application, use a low frame rate
595 and a small gop size. This is especially true for real video where
596 the Linux player does not seem to be very fast, so it can miss
597 frames. An example is:
599 @example
600 ffmpeg -g 3 -r 3 -t 10 -b 50 -s qcif -f rv10 /tmp/b.rm
601 @end example
603 @item The parameter 'q' which is displayed while encoding is the current
604 quantizer. The value of 1 indicates that a very good quality could
605 be achieved. The value of 31 indicates the worst quality. If q=31
606 too often, it means that the encoder cannot compress enough to meet
607 your bit rate. You must either increase the bit rate, decrease the
608 frame rate or decrease the frame size.
610 @item If your computer is not fast enough, you can speed up the
611 compression at the expense of the compression ratio. You can use
612 '-me zero' to speed up motion estimation, and '-intra' to disable
613 completely motion estimation (you have only I frames, which means it
614 is about as good as JPEG compression).
616 @item To have very low bitrates in audio, reduce the sampling frequency
617 (down to 22050 kHz for mpeg audio, 22050 or 11025 for ac3).
619 @item To have a constant quality (but a variable bitrate), use the option
620 '-qscale n' when 'n' is between 1 (excellent quality) and 31 (worst
621 quality).
623 @item When converting video files, you can use the '-sameq' option which
624 uses in the encoder the same quality factor than in the decoder. It
625 allows to be almost lossless in encoding.
627 @end itemize
629 @chapter Supported File Formats and Codecs
631 You can use the @code{-formats} option to have an exhaustive list.
633 @section File Formats
635 FFmpeg supports the following file formats through the @code{libavformat}
636 library:
638 @multitable @columnfractions .4 .1 .1
639 @item Supported File Format @tab Encoding @tab Decoding @tab Comments
640 @item MPEG audio @tab X @tab X
641 @item MPEG1 systems @tab X @tab X
642 @tab muxed audio and video
643 @item MPEG2 PS @tab X @tab X
644 @tab also known as @code{VOB} file
645 @item MPEG2 TS @tab @tab X
646 @tab also known as DVB Transport Stream
647 @item ASF@tab X @tab X
648 @item AVI@tab X @tab X
649 @item WAV@tab X @tab X
650 @item Macromedia Flash@tab X @tab X
651 @tab Only embedded audio is decoded
652 @item FLV @tab X @tab X
653 @tab Macromedia Flash video files
654 @item Real Audio and Video @tab X @tab X
655 @item Raw AC3 @tab X @tab X
656 @item Raw MJPEG @tab X @tab X
657 @item Raw MPEG video @tab X @tab X
658 @item Raw PCM8/16 bits, mulaw/Alaw@tab X @tab X
659 @item Raw CRI ADX audio @tab X @tab X
660 @item Raw Shorten audio @tab @tab X
661 @item SUN AU format @tab X @tab X
662 @item NUT @tab X @tab X @tab NUT Open Container Format
663 @item Quicktime @tab X @tab X
664 @item MPEG4 @tab X @tab X
665 @tab MPEG4 is a variant of Quicktime
666 @item Raw MPEG4 video @tab X @tab X
667 @item DV @tab X @tab X
668 @item 4xm @tab @tab X
669 @tab 4X Technologies format, used in some games
670 @item Playstation STR @tab @tab X
671 @item Id RoQ @tab @tab X
672 @tab used in Quake III, Jedi Knight 2, other computer games
673 @item Interplay MVE @tab @tab X
674 @tab format used in various Interplay computer games
675 @item WC3 Movie @tab @tab X
676 @tab multimedia format used in Origin's Wing Commander III computer game
677 @item Sega FILM/CPK @tab @tab X
678 @tab used in many Sega Saturn console games
679 @item Westwood Studios VQA/AUD @tab @tab X
680 @tab Multimedia formats used in Westwood Studios games
681 @item Id Cinematic (.cin) @tab @tab X
682 @tab Used in Quake II
683 @item FLIC format @tab @tab X
684 @tab .fli/.flc files
685 @item Sierra VMD @tab @tab X
686 @tab used in Sierra CD-ROM games
687 @item Sierra Online @tab @tab X
688 @tab .sol files used in Sierra Online games
689 @item Matroska @tab @tab X
690 @item Electronic Arts Multimedia @tab @tab X
691 @tab used in various EA games; files have extensions like WVE and UV2
692 @item Nullsoft Video (NSV) format @tab @tab X
693 @end multitable
695 @code{X} means that the encoding (resp. decoding) is supported.
697 @section Image Formats
699 FFmpeg can read and write images for each frame of a video sequence. The
700 following image formats are supported:
702 @multitable @columnfractions .4 .1 .1
703 @item Supported Image Format @tab Encoding @tab Decoding @tab Comments
704 @item PGM, PPM @tab X @tab X
705 @item PAM @tab X @tab X @tab PAM is a PNM extension with alpha support
706 @item PGMYUV @tab X @tab X @tab PGM with U and V components in YUV 4:2:0
707 @item JPEG @tab X @tab X @tab Progressive JPEG is not supported
708 @item .Y.U.V @tab X @tab X @tab One raw file per component
709 @item Animated GIF @tab X @tab X @tab Only uncompressed GIFs are generated
710 @item PNG @tab X @tab X @tab 2 bit and 4 bit/pixel not supported yet
711 @item SGI @tab X @tab X @tab SGI RGB image format
712 @end multitable
714 @code{X} means that the encoding (resp. decoding) is supported.
716 @section Video Codecs
718 @multitable @columnfractions .4 .1 .1 .7
719 @item Supported Codec @tab Encoding @tab Decoding @tab Comments
720 @item MPEG1 video @tab X @tab X
721 @item MPEG2 video @tab X @tab X
722 @item MPEG4 @tab X @tab X @tab Also known as DIVX4/5
723 @item MSMPEG4 V1 @tab X @tab X
724 @item MSMPEG4 V2 @tab X @tab X
725 @item MSMPEG4 V3 @tab X @tab X @tab Also known as DIVX3
726 @item WMV7 @tab X @tab X
727 @item WMV8 @tab X @tab X @tab Not completely working
728 @item H.261 @tab X @tab X
729 @item H.263(+) @tab X @tab X @tab Also known as Real Video 1.0
730 @item H.264 @tab @tab X
731 @item MJPEG @tab X @tab X
732 @item Lossless MJPEG @tab X @tab X
733 @item Apple MJPEG-B @tab @tab X
734 @item Sunplus MJPEG @tab @tab X @tab fourcc: SP5X
735 @item DV @tab X @tab X
736 @item Huff YUV @tab X @tab X
737 @item FFmpeg Video 1 @tab X @tab X @tab Experimental lossless codec (fourcc: FFV1)
738 @item FFmpeg Snow @tab X @tab X @tab Experimental wavelet codec (fourcc: SNOW)
739 @item Asus v1 @tab X @tab X @tab fourcc: ASV1
740 @item Asus v2 @tab X @tab X @tab fourcc: ASV2
741 @item Creative YUV @tab @tab X @tab fourcc: CYUV
742 @item Sorenson Video 1 @tab X @tab X @tab fourcc: SVQ1
743 @item Sorenson Video 3 @tab @tab X @tab fourcc: SVQ3
744 @item On2 VP3 @tab @tab X @tab still experimental
745 @item Theora @tab @tab X @tab still experimental
746 @item Intel Indeo 3 @tab @tab X @tab only works on i386 right now
747 @item FLV @tab X @tab X @tab Sorenson H.263 used in Flash
748 @item ATI VCR1 @tab @tab X @tab fourcc: VCR1
749 @item ATI VCR2 @tab @tab X @tab fourcc: VCR2
750 @item Cirrus Logic AccuPak @tab @tab X @tab fourcc: CLJR
751 @item 4X Video @tab @tab X @tab used in certain computer games
752 @item Sony Playstation MDEC @tab @tab X
753 @item Id RoQ @tab @tab X @tab used in Quake III, Jedi Knight 2, other computer games
754 @item Xan/WC3 @tab @tab X @tab used in Wing Commander III .MVE files
755 @item Interplay Video @tab @tab X @tab used in Interplay .MVE files
756 @item Apple Animation @tab @tab X @tab fourcc: 'rle '
757 @item Apple Graphics @tab @tab X @tab fourcc: 'smc '
758 @item Apple Video @tab @tab X @tab fourcc: rpza
759 @item Apple QuickDraw @tab @tab X @tab fourcc: qdrw
760 @item Cinepak @tab @tab X
761 @item Microsoft RLE @tab @tab X
762 @item Microsoft Video-1 @tab @tab X
763 @item Westwood VQA @tab @tab X
764 @item Id Cinematic Video @tab @tab X @tab used in Quake II
765 @item Planar RGB @tab @tab X @tab fourcc: 8BPS
766 @item FLIC video @tab @tab X
767 @item Duck TrueMotion v1 @tab @tab X @tab fourcc: DUCK
768 @item VMD Video @tab @tab X @tab used in Sierra VMD files
769 @item MSZH @tab @tab X @tab Part of LCL
770 @item ZLIB @tab X @tab X @tab Part of LCL, encoder experimental
771 @item TechSmith Camtasia @tab @tab X @tab fourcc: TSCC
772 @item IBM Ultimotion @tab @tab X @tab fourcc: ULTI
773 @item Miro VideoXL @tab @tab X @tab fourcc: VIXL
774 @item QPEG @tab @tab X @tab fourccs: QPEG, Q1.0, Q1.1
775 @end multitable
777 @code{X} means that the encoding (resp. decoding) is supported.
779 Check at @url{} to
780 get a precise comparison of FFmpeg MPEG4 codec compared to the other
781 solutions.
783 @section Audio Codecs
785 @multitable @columnfractions .4 .1 .1 .1 .7
786 @item Supported Codec @tab Encoding @tab Decoding @tab Comments
787 @item MPEG audio layer 2 @tab IX @tab IX
788 @item MPEG audio layer 1/3 @tab IX @tab IX
789 @tab MP3 encoding is supported through the external library LAME
790 @item AC3 @tab IX @tab IX
791 @tab liba52 is used internally for decoding
792 @item Vorbis @tab X @tab X
793 @tab supported through the external library libvorbis
794 @item WMA V1/V2 @tab @tab X
795 @item AAC @tab X @tab X
796 @tab supported through the external library libfaac/libfaad
797 @item Microsoft ADPCM @tab X @tab X
798 @item MS IMA ADPCM @tab X @tab X
799 @item QT IMA ADPCM @tab @tab X
800 @item 4X IMA ADPCM @tab @tab X
801 @item G.726 ADPCM @tab X @tab X
802 @item Duck DK3 IMA ADPCM @tab @tab X
803 @tab used in some Sega Saturn console games
804 @item Duck DK4 IMA ADPCM @tab @tab X
805 @tab used in some Sega Saturn console games
806 @item Westwood Studios IMA ADPCM @tab @tab X
807 @tab used in Westwood Studios games like Command and Conquer
808 @item SMJPEG IMA ADPCM @tab @tab X
809 @tab used in certain Loki game ports
810 @item CD-ROM XA ADPCM @tab @tab X
811 @item CRI ADX ADPCM @tab X @tab X
812 @tab used in Sega Dreamcast games
813 @item Electronic Arts ADPCM @tab @tab X
814 @tab used in various EA titles
815 @item Creative ADPCM @tab @tab X
816 @item RA144 @tab @tab X
817 @tab Real 14400 bit/s codec
818 @item RA288 @tab @tab X
819 @tab Real 28800 bit/s codec
820 @item RADnet @tab X @tab IX
821 @tab Real lowbitrate AC3 codec, liba52 is used for decoding
822 @item AMR-NB @tab X @tab X
823 @tab supported through an external library
824 @item AMR-WB @tab X @tab X
825 @tab supported through an external library
826 @item DV audio @tab @tab X
827 @item Id RoQ DPCM @tab @tab X
828 @tab used in Quake III, Jedi Knight 2, other computer games
829 @item Interplay MVE DPCM @tab @tab X
830 @tab used in various Interplay computer games
831 @item Xan DPCM @tab @tab X
832 @tab used in Origin's Wing Commander IV AVI files
833 @item Sierra Online DPCM @tab @tab X
834 @tab used in Sierra Online game audio files
835 @item Apple MACE 3 @tab @tab X
836 @item Apple MACE 6 @tab @tab X
837 @item FLAC lossless audio @tab @tab X
838 @item Shorten lossless audio @tab @tab X
839 @item FFmpeg Sonic @tab X @tab X
840 @tab Experimental lossy/lossless codec
841 @end multitable
843 @code{X} means that the encoding (resp. decoding) is supported.
845 @code{I} means that an integer only version is available too (ensures highest
846 performances on systems without hardware floating point support).
848 @chapter Platform Specific information
850 @section Linux
852 ffmpeg should be compiled with at least GCC 2.95.3. GCC 3.2 is the
853 preferred compiler now for ffmpeg. All future optimizations will depend on
854 features only found in GCC 3.2.
856 @section BSD
858 @section Windows
860 @subsection Native Windows compilation
862 @itemize
863 @item Install the current versions of MSYS and MinGW from
864 @url{}. You can find detailed installation
865 instructions in the download section and the FAQ.
867 @item If you want to test the FFmpeg Simple Media Player, also download
868 the MinGW development library of SDL 1.2.x
869 (@file{SDL-devel-1.2.x-mingw32.tar.gz}) from
870 @url{}. Unpack it in a temporary place, and
871 unpack the archive @file{i386-mingw32msvc.tar.gz} in the MinGW tool
872 directory. Edit the @file{sdl-config} script so that it gives the
873 correct SDL directory when invoked.
875 @item Extract the current version of FFmpeg (the latest release version or the current CVS snapshot whichever is recommended).
877 @item Start the MSYS shell (file @file{msys.bat}).
879 @item Change to the FFMPEG directory and follow
880 the instructions of how to compile ffmpeg (file
881 @file{INSTALL}). Usually, launching @file{./configure} and @file{make}
882 suffices. If you have problems using SDL, verify that
883 @file{sdl-config} can be launched from the MSYS command line.
885 @item You can install FFmpeg in @file{Program Files/FFmpeg} by typing @file{make install}. Don't forget to copy @file{SDL.dll} at the place you launch
886 @file{ffplay}.
888 @end itemize
890 Notes:
891 @itemize
893 @item The target @file{make wininstaller} can be used to create a
894 Nullsoft based Windows installer for FFmpeg and FFplay. @file{SDL.dll}
895 must be copied in the ffmpeg directory in order to build the
896 installer.
898 @item By using @code{./configure --enable-shared} when configuring ffmpeg,
899 you can build @file{avcodec.dll} and @file{avformat.dll}. With
900 @code{make install} you install the FFmpeg DLLs and the associated
901 headers in @file{Program Files/FFmpeg}.
903 @item Visual C++ compatibility: if you used @code{./configure --enable-shared}
904 when configuring FFmpeg, then FFmpeg tries to use the Microsoft Visual
905 C++ @code{lib} tool to build @code{avcodec.lib} and
906 @code{avformat.lib}. With these libraries, you can link your Visual C++
907 code directly with the FFmpeg DLLs.
909 @end itemize
911 @subsection Cross compilation for Windows with Linux
913 You must use the MinGW cross compilation tools available at
914 @url{}.
916 Then configure ffmpeg with the following options:
917 @example
918 ./configure --enable-mingw32 --cross-prefix=i386-mingw32msvc-
919 @end example
920 (you can change the cross-prefix according to the prefix choosen for the
921 MinGW tools).
923 Then you can easily test ffmpeg with wine
924 (@url{}).
926 @section MacOS X
928 @section BeOS
930 The configure script should guess the configuration itself.
931 Networking support is currently not finished.
932 errno issues fixed by Andrew Bachmann.
934 Old stuff:
936 François Revol - revol at free dot fr - April 2002
938 The configure script should guess the configuration itself,
939 however I still didn't tested building on net_server version of BeOS.
941 ffserver is broken (needs poll() implementation).
943 There is still issues with errno codes, which are negative in BeOs, and
944 that ffmpeg negates when returning. This ends up turning errors into
945 valid results, then crashes.
946 (To be fixed)
948 @chapter Developers Guide
950 @section API
951 @itemize
952 @item libavcodec is the library containing the codecs (both encoding and
953 decoding). See @file{libavcodec/apiexample.c} to see how to use it.
955 @item libavformat is the library containing the file formats handling (mux and
956 demux code for several formats). See @file{ffplay.c} to use it in a
957 player. See @file{output_example.c} to use it to generate audio or video
958 streams.
960 @end itemize
962 @section Integrating libavcodec or libavformat in your program
964 You can integrate all the source code of the libraries to link them
965 statically to avoid any version problem. All you need is to provide a
966 'config.mak' and a 'config.h' in the parent directory. See the defines
967 generated by ./configure to understand what is needed.
969 You can use libavcodec or libavformat in your commercial program, but
970 @emph{any patch you make must be published}. The best way to proceed is
971 to send your patches to the ffmpeg mailing list.
973 @node Coding Rules
974 @section Coding Rules
976 ffmpeg is programmed in the ISO C90 language with a few additional
977 features from ISO C99, namely:
978 @itemize @bullet
979 @item
980 the @samp{inline} keyword;
981 @item
982 @samp{//} comments;
983 @item
984 designated struct initializers (@samp{struct s x = @{ .i = 17 @};})
985 @item
986 compound literals (@samp{x = (struct s) @{ 17, 23 @};})
987 @end itemize
989 These features are supported by all compilers we care about, so we won't
990 accept patches to remove their use unless they absolutely don't impair
991 clarity and performance.
993 All code must compile with gcc 2.95 and gcc 3.3. Currently, ffmpeg also
994 compiles with several other compilers, such as the Compaq ccc compiler
995 or Sun Studio 9, and we would like to keep it that way unless it would
996 be exceedingly involved. To ensure compatibility, please don't use any
997 additional C99 features or gcc extensions. Watch out especially for:
998 @itemize @bullet
999 @item
1000 mixing statements and declarations;
1001 @item
1002 @samp{long long} (use @samp{int64_t} instead);
1003 @item
1004 @samp{__attribute__} not protected by @samp{#ifdef __GNUC__} or similar;
1005 @item
1006 gcc statement expressions (@samp{(x = (@{ int y = 4; y; @})}).
1007 @end itemize
1009 Indent size is 4. The TAB character should not be used.
1010 The presentation is the one specified by 'indent -i4 -kr'.
1012 Main priority in ffmpeg is simplicity and small code size (=less
1013 bugs).
1015 Comments: use the JavaDoc/Doxygen
1016 format (see examples below) so that a documentation
1017 can be generated automatically. All non trivial functions should have a comment
1018 above it explaining what the function does, even if its just one sentance.
1019 All Structures and their member variables should be documented too.
1020 @example
1021 /**
1022  * @@file mpeg.c
1023  * mpeg codec.
1024  * @@author ...
1025  */
1027 /**
1028  * Summary sentance.
1029  * more text ...
1030  * ...
1031  */
1032 typedef struct Foobar@{
1033     int var1; /**< var1 description */
1034     int var2; ///< var2 description
1035     /** var3 description */
1036     int var3;
1037 @} Foobar;
1039 /**
1040  * Summary sentance.
1041  * more text ...
1042  * ...
1043  * @@param my_parameter description of my_parameter
1044  * @@return return value description
1045  */
1046 int myfunc(int my_parameter)
1047 ...
1048 @end example
1050 fprintf and printf are forbidden in libavformat and libavcodec,
1051 please use av_log() instead.
1053 @node CVS Policy
1054 @section CVS Policy
1056 @enumerate
1057 @item
1058 You must not commit code which breaks FFmpeg! (Meaning unfinished but
1059 enabled code which breaks compilation or compiles but does not work. Or
1060 breaks the regression tests)
1061 You can commit unfinished stuff (for testing etc), but it must be disabled
1062 (#ifdef etc) by default so it does not interfere with other developers'
1063 work.
1064 @item
1065 You don't have to over-test things. If it works for you, and you think it
1066 should work for others, too, then commit. If your code has problems
1067 (portability, exploits compiler bugs, unusual environment etc) they will be
1068 reported and eventually fixed.
1069 @item
1070 Do not commit unrelated changes together, split them into self-contained
1071 pieces.
1072 @item
1073 Do not change behavior of the program (renaming options etc) without
1074 first discussing it on the ffmpeg-dev mailing list. Do not remove
1075 functionality from the code. Just improve!
1077 Note: Redundant code can be removed
1078 @item
1079 Do not commit changes to the build system (Makefiles, configure script)
1080 which change behaviour, defaults etc, without asking first. The same
1081 applies to compiler warning fixes, trivial looking fixes and to code
1082 maintained by other developers. We usually have a reason for doing things
1083 the way we do. Send your changes as patches to the ffmpeg-dev mailing
1084 list, and if the code maintainers say OK, you may commit. This does not
1085 apply to files you wrote and/or maintain.
1086 @item
1087 We refuse source indentation and other cosmetic changes if they are mixed
1088 with functional changes, such commits will be rejected and removed. Every
1089 developer has his own indentation style, you should not change it. Of course
1090 if you (re)write something, you can use your own style, even though we would
1091 prefer if the indention throughout ffmpeg would be consistant (Many projects
1092 force a given indentation style - we don't.) If you really need to make
1093 indentation changes (try to avoid this), separate them strictly from real
1094 changes.
1096 NOTE: If you had to put if()@{ .. @} over a large (> 5 lines) chunk of code,
1097 then either do NOT change the indentation of the inner part within (don't
1098 move it to the right)! or do so in a seperate commit
1099 @item
1100 Always fill out the commit log message. Describe in a few lines what you
1101 changed and why. You can refer to mailing list postings if you fix a
1102 particular bug. Comments such as "fixed!" or "Changed it." are unacceptable.
1103 @item
1104 If you apply a patch by someone else, include the name and email address in
1105 the CVS log message. Since the ffmpeg-cvslog mailing list is publicly
1106 archived you should add some spam protection to the email address. Send an
1107 answer to ffmpeg-dev (or wherever you got the patch from) saying that
1108 you applied the patch.
1109 @item
1110 Do NOT commit to code actively maintained by others without permission. Send
1111 a patch to ffmpeg-dev instead.
1112 @item
1113 Subscribe to the ffmpeg-cvslog mailing list. The diffs of all CVS commits
1114 are sent there and reviewed by all the other developers. Bugs and possible
1115 improvements or general questions regarding commits are discussed there. We
1116 expect you to react if problems with your code are uncovered.
1117 @item
1118 Update the documentation if you change behavior or add features. If you are
1119 unsure how best to do this, send a patch to ffmpeg-dev, the documentation
1120 maintainer(s) will review and commit your stuff.
1121 @item
1122 Revert a commit ONLY in case of a big blunder like committing something not
1123 intended to be committed or committing a wrong file, the wrong version of a
1124 patch, cvs policy violation or broken code and you are going to recommit the
1125 right thing immediately.
1127 Never revert changes made a long time ago or buggy code. Fix it in the
1128 normal way instead.
1129 @item
1130 Never write to not allocated memory, never write over the end of arrays,
1131 always check values read from some untrusted source before using them as index
1132 into an array or otherwise risky things.
1133 @end enumerate
1135 We think our rules are not too hard. If you have comments, contact us.
1137 Note, these rules are mostly borrowed from the MPlayer project.
1139 @subsection Renaming/moving files or content of files
1140 You CANNOT do that. Post a request for such a change to the mailinglist
1141 Do NOT remove & readd a file - it will kill the changelog!!!!
1143 @section Submitting patches
1145 First, (@pxref{Coding Rules}) above if you didn't yet.
1147 When you submit your patch, try to send a unified diff (diff '-up'
1148 option). I cannot read other diffs :-)
1150 Run the regression tests before submitting a patch so that you can
1151 verify that there are no big problems.
1153 Patches should be posted as base64 encoded attachments (or any other
1154 encoding which ensures that the patch wont be trashed during
1155 transmission) to the ffmpeg-devel mailinglist, see
1156 @url{}
1158 It also helps quite a bit if you tell us what the patch does (for example
1159 'replaces lrint by lrintf') , and why (for example '*bsd isnt c99 compliant
1160 and has no lrint()')
1162 We reply to all patches submitted and either apply or reject with some
1163 explanation why, but sometimes we are quite busy so it can take a week or 2
1165 @section Regression tests
1167 Before submitting a patch (or committing with CVS), you should at least
1168 test that you did not break anything.
1170 The regression test build a synthetic video stream and a synthetic
1171 audio stream. Then these are encoded then decoded with all codecs or
1172 formats. The CRC (or MD5) of each generated file is recorded in a
1173 result file. Then a 'diff' is launched with the reference results and
1174 the result file.
1176 The regression test then goes on to test the ffserver code with a
1177 limited set of streams. It is important that this step runs correctly
1178 as well.
1180 Run 'make test' to test all the codecs and formats.
1182 Run 'make fulltest' to test all the codecs, formats and ffserver.
1184 [Of course, some patches may change the regression tests results. In
1185 this case, the regression tests reference results shall be modified
1186 accordingly].
1188 @bye