1 \input texinfo @c -*- texinfo -*-
3 @settitle FFmpeg Documentation
6 @center @titlefont{FFmpeg Documentation}
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.
26 @section Video and Audio grabbing
28 FFmpeg can use a video4linux compatible video source and any Open Sound
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{http://bytesex.org/xawtv/}) by Gerd Knorr which I find very
38 good. You must also set correctly the audio recording levels with a
41 @section Video and Audio file format conversion
43 * ffmpeg can use any supported file format and protocol as input:
47 * You can input from YUV files:
50 ffmpeg -i /tmp/test%d.Y /tmp/out.mpg
53 It will use the files:
55 /tmp/test0.Y, /tmp/test0.U, /tmp/test0.V,
56 /tmp/test1.Y, /tmp/test1.U, /tmp/test1.V, etc...
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:
67 ffmpeg -i /tmp/test.yuv /tmp/out.avi
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:
77 ffmpeg -i mydivx.avi -o hugefile.yuv
80 * You can set several input files and output files:
83 ffmpeg -i /tmp/a.wav -s 640x480 -i /tmp/a.yuv /tmp/a.mpg
86 Convert the audio file a.wav and the raw yuv video file a.yuv
89 * You can also do audio and video conversions at the same time:
92 ffmpeg -i /tmp/a.wav -ar 22050 /tmp/a.mp2
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:
101 ffmpeg -i /tmp/a.wav -ab 64 /tmp/a.mp2 -ab 128 /tmp/b.mp2 -map 0:0 -map 0:0
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
111 ffmpeg -i snatch_1.vob -f avi -vcodec mpeg4 -b 800 -g 300 -bf 2 -acodec mp3 -ab 128 snatch.avi
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}.
130 The generic syntax is:
133 @c man begin SYNOPSIS
134 ffmpeg [[options][@option{-i} @var{input_file}]]... @{[options] @var{output_file}@}...
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
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.
151 @section Main options
161 show available formats, codecs, protocols, ...
170 overwrite output files
173 set the recording time in seconds. @code{hh:mm:ss[.xxx]} syntax is also
182 @item -copyright string
185 @item -comment string
189 activate high quality settings
193 @section Video Options
197 set the video bitrate in kbit/s (default = 200 kb/s)
199 set frame rate (default = 25)
201 set frame size. The format is @samp{WxH} (default 160x128). The
202 following abbreviations are recognized:
215 set aspect ratio (4:3, 16:9 or 1.3333, 1.7777)
217 set top crop band size (in pixels)
218 @item -cropbottom size
219 set bottom crop band size (in pixels)
221 set left crop band size (in pixels)
222 @item -cropright size
223 set right crop band size (in pixels)
225 disable video recording
227 set video bitrate tolerance (in kbit/s)
228 @item -maxrate bitrate
229 set max video bitrate tolerance (in kbit/s)
230 @item -minrate bitrate
231 set min video bitrate tolerance (in kbit/s)
233 set ratecontrol buffere size (in kbit)
235 force video codec to @var{codec}. Use the @code{copy} special value to
236 tell that the raw codec data must be copied as is.
238 use same video quality as source (implies VBR)
241 select the pass number (1 or 2). It is useful to do two pass
242 encoding. The statistics of the video are recorded in the first pass and
243 the video at the exact requested bit rate is generated in the second
246 @item -passlogfile file
247 select two pass log file name to @var{file}.
251 @section Advanced Video Options
255 set the group of picture size
257 use only intra frames
259 use fixed video quantiser scale (VBR)
261 min video quantiser scale (VBR)
263 max video quantiser scale (VBR)
265 max difference between the quantiser scale (VBR)
267 video quantiser scale blur (VBR)
268 @item -qcomp compression
269 video quantiser scale compression (VBR)
271 @item -rc_init_cplx complexity
272 initial complexity for 1-pass encoding
273 @item -b_qfactor factor
274 qp factor between p and b frames
275 @item -i_qfactor factor
276 qp factor between p and i frames
277 @item -b_qoffset offset
278 qp offset between p and b frames
279 @item -i_qoffset offset
280 qp offset between p and i frames
281 @item -rc_eq equation
282 set rate control equation (@pxref{FFmpeg formula
283 evaluator}). Default is @code{tex^qComp}.
284 @item -rc_override override
285 rate control override for specific intervals
287 set motion estimation method to @var{method}. Available methods are
288 (from lower to best quality):
291 Try just the (0, 0) vector.
298 exhaustive search (slow and marginally better than epzs)
302 set dct algorithm to @var{algo}. Available values are:
305 FF_DCT_AUTO (default)
318 @item -idct_algo algo
319 set idct algorithm to @var{algo}. Available values are:
322 FF_IDCT_AUTO (default)
346 set error resilience to @var{n}.
349 FF_ER_CAREFULL (default)
355 FF_ER_VERY_AGGRESSIVE
359 set error concealment to @var{bit_mask}. @var{bit_mask} is a bit mask of
360 the following values:
363 FF_EC_GUESS_MVS (default=enabled)
365 FF_EC_DEBLOCK (default=enabled)
369 use 'frames' B frames (supported for MPEG-1, MPEG-2 and MPEG-4)
374 FF_MB_DECISION_SIMPLE: use mb_cmp (cannot change it yet in ffmpeg)
376 FF_MB_DECISION_BITS: chooses the one which needs the fewest bits
378 FF_MB_DECISION_RD: rate distoration
382 use four motion vector by macroblock (only MPEG-4)
384 use data partitioning (only MPEG-4)
386 workaround not auto detected encoder bugs
387 @item -strict strictness
388 how strictly to follow the standarts
390 enable Advanced intra coding (h263+)
392 enable Unlimited Motion Vector (h263+)
397 calculate PSNR of compressed frames
399 dump video coding statistics to @file{vstats_HHMMSS.log}.
401 insert video processing @var{module}. @var{module} contains the module
402 name and its parameters separated by spaces.
405 @section Audio Options
409 set audio bitrate (in kbit/s)
411 set the audio sampling freq (default = 44100 Hz)
413 set the audio bitrate in kbit/s (default = 64)
415 set the number of audio channels (default = 1)
417 disable audio recording
419 force audio codec to @var{codec}. Use the @code{copy} special value to
420 tell that the raw codec data must be copied as is.
423 @section Audio/Video grab options
427 set video grab device (e.g. @file{/dev/video0})
429 set video grab channel (DV1394 only)
430 @item -tvstd standard
431 set television standard (NTSC, PAL (SECAM))
435 set audio device (e.g. @file{/dev/dsp})
438 @section Advanced options
441 @item -map file:stream
442 set input stream mapping
444 print specific debug info
446 add timings for benchmarking
448 dump each input packet
450 only use bit exact algorithms (for codec testing)
452 set packet size in bits
454 read input at native frame rate. Mainly used to simulate a grab device.
456 loop over the input stream. Currently it works only for image
457 streams. This option is used for ffserver automatic testing.
460 @node FFmpeg formula evaluator
461 @section FFmpeg formula evaluator
463 When evaluating a rate control string, FFmpeg uses an internal formula
466 The following binary operators are available: @code{+}, @code{-},
467 @code{*}, @code{/}, @code{^}.
469 The following unary operators are available: @code{+}, @code{-},
472 The following functions are available:
494 The following constants are available:
523 @settitle FFmpeg video converter
526 ffserver(1), ffplay(1) and the html documentation of @file{ffmpeg}.
537 The filename can be @file{-} to read from the standard input or to write
538 to the standard output.
540 ffmpeg handles also many protocols specified with the URL syntax.
542 Use 'ffmpeg -formats' to have a list of the supported protocols.
544 The protocol @code{http:} is currently used only to communicate with
545 ffserver (see the ffserver documentation). When ffmpeg will be a
546 video player it will also be used for streaming :-)
551 @item For streaming at very low bit rate application, use a low frame rate
552 and a small gop size. This is especially true for real video where
553 the Linux player does not seem to be very fast, so it can miss
554 frames. An example is:
557 ffmpeg -g 3 -r 3 -t 10 -b 50 -s qcif -f rv10 /tmp/b.rm
560 @item The parameter 'q' which is displayed while encoding is the current
561 quantizer. The value of 1 indicates that a very good quality could
562 be achieved. The value of 31 indicates the worst quality. If q=31
563 too often, it means that the encoder cannot compress enough to meet
564 your bit rate. You must either increase the bit rate, decrease the
565 frame rate or decrease the frame size.
567 @item If your computer is not fast enough, you can speed up the
568 compression at the expense of the compression ratio. You can use
569 '-me zero' to speed up motion estimation, and '-intra' to disable
570 completely motion estimation (you have only I frames, which means it
571 is about as good as JPEG compression).
573 @item To have very low bitrates in audio, reduce the sampling frequency
574 (down to 22050 kHz for mpeg audio, 22050 or 11025 for ac3).
576 @item To have a constant quality (but a variable bitrate), use the option
577 '-qscale n' when 'n' is between 1 (excellent quality) and 31 (worst
580 @item When converting video files, you can use the '-sameq' option which
581 uses in the encoder the same quality factor than in the decoder. It
582 allows to be almost lossless in encoding.
586 @chapter Supported File Formats and Codecs
588 You can use the @code{-formats} option to have an exhaustive list.
590 @section File Formats
592 FFmpeg supports the following file formats through the @code{libavformat}
595 @multitable @columnfractions .4 .1 .1
596 @item Supported File Format @tab Encoding @tab Decoding @tab Comments
597 @item MPEG audio @tab X @tab X
598 @item MPEG1 systems @tab X @tab X
599 @tab muxed audio and video
600 @item MPEG2 PS @tab X @tab X
601 @tab also known as @code{VOB} file
602 @item MPEG2 TS @tab @tab X
603 @tab also known as DVB Transport Stream
604 @item ASF@tab X @tab X
605 @item AVI@tab X @tab X
606 @item WAV@tab X @tab X
607 @item Macromedia Flash@tab X @tab X
608 @tab Only embedded audio is decoded
609 @item FLV @tab X @tab X
610 @tab Macromedia Flash video files
611 @item Real Audio and Video @tab X @tab X
612 @item Raw AC3 @tab X @tab X
613 @item Raw MJPEG @tab X @tab X
614 @item Raw MPEG video @tab X @tab X
615 @item Raw PCM8/16 bits, mulaw/Alaw@tab X @tab X
616 @item SUN AU format @tab X @tab X
617 @item Quicktime @tab X @tab X
618 @item MPEG4 @tab X @tab X
619 @tab MPEG4 is a variant of Quicktime
620 @item Raw MPEG4 video @tab X @tab X
622 @item 4xm @tab @tab X
623 @tab 4X Technologies format, used in some games
624 @item Playstation STR @tab @tab X
625 @item Id RoQ @tab @tab X
626 @tab used in Quake III, Jedi Knight 2, other computer games
627 @item Interplay MVE @tab @tab X
628 @tab format used in various Interplay computer games
629 @item WC3 Movie @tab @tab X
630 @tab multimedia format used in Origin's Wing Commander III computer game
631 @item Sega FILM/CPK @tab @tab X
632 @tab used in many Sega Saturn console games
633 @item Westwood Studios VQA/AUD @tab @tab X
634 @tab Multimedia formats used in Westwood Studios games
637 @code{X} means that the encoding (resp. decoding) is supported.
639 @section Image Formats
641 FFmpeg can read and write images for each frame of a video sequence. The
642 following image formats are supported:
644 @multitable @columnfractions .4 .1 .1
645 @item Supported Image Format @tab Encoding @tab Decoding @tab Comments
646 @item PGM, PPM @tab X @tab X
647 @item PAM @tab X @tab X @tab PAM is a PNM extension with alpha support
648 @item PGMYUV @tab X @tab X @tab PGM with U and V components in YUV 4:2:0
649 @item JPEG @tab X @tab X @tab Progressive JPEG is not supported
650 @item .Y.U.V @tab X @tab X @tab One raw file per component
651 @item Animated GIF @tab X @tab X @tab Only uncompressed GIFs are generated
652 @item PNG @tab X @tab X @tab 2 bit and 4 bit/pixel not supported yet
655 @code{X} means that the encoding (resp. decoding) is supported.
657 @section Video Codecs
659 @multitable @columnfractions .4 .1 .1 .7
660 @item Supported Codec @tab Encoding @tab Decoding @tab Comments
661 @item MPEG1 video @tab X @tab X
662 @item MPEG2 video @tab X @tab X
663 @item MPEG4 @tab X @tab X @tab Also known as DIVX4/5
664 @item MSMPEG4 V1 @tab X @tab X
665 @item MSMPEG4 V2 @tab X @tab X
666 @item MSMPEG4 V3 @tab X @tab X @tab Also known as DIVX3
667 @item WMV7 @tab X @tab X
668 @item WMV8 @tab X @tab X @tab Not completely working
669 @item H263(+) @tab X @tab X @tab Also known as Real Video 1.0
670 @item MJPEG @tab X @tab X
672 @item Huff YUV @tab X @tab X
673 @item Asus v1 @tab X @tab X @tab fourcc: ASV1
674 @item Asus v2 @tab X @tab X @tab fourcc: ASV2
675 @item Creative YUV @tab @tab X @tab fourcc: CYUV
676 @item H.264 @tab @tab X
677 @item Sorenson Video 1 @tab @tab X @tab fourcc: SVQ1
678 @item Sorenson Video 3 @tab @tab X @tab fourcc: SVQ3
679 @item On2 VP3 @tab @tab X @tab still experimental
680 @item Intel Indeo 3 @tab @tab X @tab only works on i386 right now
681 @item FLV @tab X @tab X @tab Flash H263 variant
682 @item ATI VCR1 @tab @tab X @tab fourcc: VCR1
683 @item Cirrus Logic AccuPak @tab @tab X @tab fourcc: CLJR
684 @item 4X Video @tab @tab X @tab used in certain computer games
685 @item Sony Playstation MDEC @tab @tab X
686 @item Id RoQ @tab @tab X @tab used in Quake III, Jedi Knight 2, other computer games
687 @item Xan/WC3 @tab @tab X @tab used in Wing Commander III .MVE files
688 @item Interplay Video @tab @tab X @tab used in Interplay .MVE files
689 @item Apple Video @tab @tab X @tab fourcc: rpza
690 @item Cinepak @tab @tab X
691 @item Microsoft RLE @tab @tab X
692 @item Microsoft Video-1 @tab @tab X
695 @code{X} means that the encoding (resp. decoding) is supported.
697 Check at @url{http://www.mplayerhq.hu/~michael/codec-features.html} to
698 get a precise comparison of FFmpeg MPEG4 codec compared to the other
701 @section Audio Codecs
703 @multitable @columnfractions .4 .1 .1 .1 .7
704 @item Supported Codec @tab Encoding @tab Decoding @tab Comments
705 @item MPEG audio layer 2 @tab IX @tab IX
706 @item MPEG audio layer 1/3 @tab IX @tab IX
707 @tab MP3 encoding is supported through the external library LAME
708 @item AC3 @tab IX @tab X
709 @tab liba52 is used internally for decoding
710 @item Vorbis @tab X @tab X
711 @tab supported through the external library libvorbis
712 @item WMA V1/V2 @tab @tab X
713 @item Microsoft ADPCM @tab X @tab X
714 @item MS IMA ADPCM @tab X @tab X
715 @item QT IMA ADPCM @tab @tab X
716 @item 4X IMA ADPCM @tab @tab X
717 @item Duck DK3 IMA ADPCM @tab @tab X
718 @tab used in some Sega Saturn console games
719 @item Duck DK4 IMA ADPCM @tab @tab X
720 @tab used in some Sega Saturn console games
721 @item Westwood Studios IMA ADPCM @tab @tab X
722 @tab used in Westwood Studios games likes Command and Conquer
723 @item RA144 @tab @tab X
724 @tab Real 14400 bit/s codec
725 @item RA288 @tab @tab X
726 @tab Real 28800 bit/s codec
727 @item AMR-NB @tab X @tab X
728 @tab supported through an external library
729 @item AMR-WB @tab X @tab X
730 @tab supported through an external library
731 @item DV audio @tab @tab X
732 @item Id RoQ DPCM @tab @tab X
733 @tab used in Quake III, Jedi Knight 2, other computer games
734 @item Interplay MVE DPCM @tab @tab X
735 @tab used in various Interplay computer games
736 @item Xan DPCM @tab @tab X
737 @tab used in Origin's Wing Commander IV AVI files
740 @code{X} means that the encoding (resp. decoding) is supported.
742 @code{I} means that an integer only version is available too (ensures highest
743 performances on systems without hardware floating point support).
745 @chapter Platform Specific information
749 ffmpeg should be compiled with at least GCC 2.95.3. GCC 3.2 is the
750 preferred compiler now for ffmpeg. All future optimizations will depend on
751 features only found in GCC 3.2.
757 @subsection Native Windows compilation
760 @item Install the current versions of MSYS and MinGW from
761 @url{http://www.mingw.org/}. You can find detailed installation
762 instructions in the download section and the FAQ.
764 @item If you want to test the FFmpeg Simple Media Player, also download
765 the MinGW development library of SDL 1.2.x
766 (@file{SDL-devel-1.2.x-mingw32.tar.gz}) from
767 @url{http://www.libsdl.org}. Unpack it in a temporary place, and
768 unpack the archive @file{i386-mingw32msvc.tar.gz} in the MinGW tool
769 directory. Edit the @file{sdl-config} script so that it gives the
770 correct SDL directory when invoked.
772 @item Extract the current version of FFmpeg (the latest release version or the current CVS snapshot whichever is recommended).
774 @item Start the MSYS shell (file @file{msys.bat}).
776 @item Change to the FFMPEG directory and follow
777 the instructions of how to compile ffmpeg (file
778 @file{INSTALL}). Usually, launching @file{./configure} and @file{make}
779 suffices. If you have problems using SDL, verify that
780 @file{sdl-config} can be launched from the MSYS command line.
782 @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
790 @item The target @file{make wininstaller} can be used to create a
791 Nullsoft based Windows installer for FFmpeg and FFplay. @file{SDL.dll}
792 must be copied in the ffmpeg directory in order to build the
795 @item By using @code{./configure --enable-shared} when configuring ffmpeg,
796 you can build @file{avcodec.dll} and @file{avformat.dll}. With
797 @code{make install} you install the FFmpeg DLLs and the associated
798 headers in @file{Program Files/FFmpeg}.
800 @item Visual C++ compatibility: if you used @code{./configure --enable-shared}
801 when configuring FFmpeg, then FFmpeg tries to use the Microsoft Visual
802 C++ @code{lib} tool to build @code{avcodec.lib} and
803 @code{avformat.lib}. With these libraries, you can link your Visual C++
804 code directly with the FFmpeg DLLs.
808 @subsection Cross compilation for Windows with Linux
810 You must use the MinGW cross compilation tools available at
811 @url{http://www.mingw.org/}.
813 Then configure ffmpeg with the following options:
815 ./configure --enable-mingw32 --cross-prefix=i386-mingw32msvc-
817 (you can change the cross-prefix according to the prefix choosen for the
820 Then you can easily test ffmpeg with wine
821 (@url{http://www.winehq.com/}).
827 The configure script should guess the configuration itself.
828 Networking support is currently not finished.
829 errno issues fixed by Andrew Bachmann.
833 François Revol - revol at free dot fr - April 2002
835 The configure script should guess the configuration itself,
836 however I still didn't tested building on net_server version of BeOS.
838 ffserver is broken (needs poll() implementation).
840 There is still issues with errno codes, which are negative in BeOs, and
841 that ffmpeg negates when returning. This ends up turning errors into
842 valid results, then crashes.
845 @chapter Developers Guide
849 @item libavcodec is the library containing the codecs (both encoding and
850 decoding). See @file{libavcodec/apiexample.c} to see how to use it.
852 @item libavformat is the library containing the file formats handling (mux and
853 demux code for several formats). See @file{ffplay.c} to use it in a
854 player. See @file{output_example.c} to use it to generate audio or video
859 @section Integrating libavcodec or libavformat in your program
861 You can integrate all the source code of the libraries to link them
862 statically to avoid any version problem. All you need is to provide a
863 'config.mak' and a 'config.h' in the parent directory. See the defines
864 generated by ./configure to understand what is needed.
866 You can use libavcodec or libavformat in your commercial program, but
867 @emph{any patch you make must be published}. The best way to proceed is
868 to send your patches to the ffmpeg mailing list.
870 @section Coding Rules
872 ffmpeg is programmed in ANSI C language. GCC extensions are
873 tolerated. Indent size is 4. The TAB character should not be used.
875 The presentation is the one specified by 'indent -i4 -kr'.
877 Main priority in ffmpeg is simplicity and small code size (=less
880 Comments: for functions visible from other modules, use the JavaDoc
881 format (see examples in @file{libav/utils.c}) so that a documentation
882 can be generated automatically.
884 @section Submitting patches
886 When you submit your patch, try to send a unified diff (diff '-u'
887 option). I cannot read other diffs :-)
889 Run the regression tests before submitting a patch so that you can
890 verify that there are no big problems.
892 Patches should be posted as base64 encoded attachments (or any other
893 encoding which ensures that the patch wont be trashed during
894 transmission) to the ffmpeg-devel mailinglist, see
895 @url{http://lists.sourceforge.net/lists/listinfo/ffmpeg-devel}
897 @section Regression tests
899 Before submitting a patch (or committing with CVS), you should at least
900 test that you did not break anything.
902 The regression test build a synthetic video stream and a synthetic
903 audio stream. Then these are encoded then decoded with all codecs or
904 formats. The CRC (or MD5) of each generated file is recorded in a
905 result file. Then a 'diff' is launched with the reference results and
908 The regression test then goes on to test the ffserver code with a
909 limited set of streams. It is important that this step runs correctly
912 Run 'make test' to test all the codecs.
914 Run 'make fulltest' to test all the codecs, formats and ffserver.
916 [Of course, some patches may change the regression tests results. In
917 this case, the regression tests reference results shall be modified