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 parameters that can possibly be
18 derived automatically. You usually only have to specify the target
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.
27 @section Video and Audio grabbing
29 FFmpeg can grab video and audio from devices given that you specify the input
33 ffmpeg -f oss -i /dev/dsp -f video4linux2 -i /dev/video0 /tmp/out.mpg
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://linux.bytesex.org/xawtv/}) by Gerd Knorr. You also
39 have to set the audio recording levels correctly with a
44 FFmpeg can grab the X11 display.
47 ffmpeg -f x11grab -s cif -i :0.0 /tmp/out.mpg
50 0.0 is display.screen number of your X11 server, same as
51 the DISPLAY environment variable.
54 ffmpeg -f x11grab -s cif -i :0.0+10,20 /tmp/out.mpg
57 0.0 is display.screen number of your X11 server, same as the DISPLAY environment
58 variable. 10 is the x-offset and 20 the y-offset for the grabbing.
60 @section Video and Audio file format conversion
62 * FFmpeg can use any supported file format and protocol as input:
66 * You can use YUV files as input:
69 ffmpeg -i /tmp/test%d.Y /tmp/out.mpg
72 It will use the files:
74 /tmp/test0.Y, /tmp/test0.U, /tmp/test0.V,
75 /tmp/test1.Y, /tmp/test1.U, /tmp/test1.V, etc...
78 The Y files use twice the resolution of the U and V files. They are
79 raw files, without header. They can be generated by all decent video
80 decoders. You must specify the size of the image with the @option{-s} option
81 if FFmpeg cannot guess it.
83 * You can input from a raw YUV420P file:
86 ffmpeg -i /tmp/test.yuv /tmp/out.avi
89 test.yuv is a file containing raw YUV planar data. Each frame is composed
90 of the Y plane followed by the U and V planes at half vertical and
91 horizontal resolution.
93 * You can output to a raw YUV420P file:
96 ffmpeg -i mydivx.avi hugefile.yuv
99 * You can set several input files and output files:
102 ffmpeg -i /tmp/a.wav -s 640x480 -i /tmp/a.yuv /tmp/a.mpg
105 Converts the audio file a.wav and the raw YUV video file a.yuv
108 * You can also do audio and video conversions at the same time:
111 ffmpeg -i /tmp/a.wav -ar 22050 /tmp/a.mp2
114 Converts a.wav to MPEG audio at 22050 Hz sample rate.
116 * You can encode to several formats at the same time and define a
117 mapping from input stream to output streams:
120 ffmpeg -i /tmp/a.wav -ab 64k /tmp/a.mp2 -ab 128k /tmp/b.mp2 -map 0:0 -map 0:0
123 Converts a.wav to a.mp2 at 64 kbits and to b.mp2 at 128 kbits. '-map
124 file:index' specifies which input stream is used for each output
125 stream, in the order of the definition of output streams.
127 * You can transcode decrypted VOBs:
130 ffmpeg -i snatch_1.vob -f avi -vcodec mpeg4 -b 800k -g 300 -bf 2 -acodec libmp3lame -ab 128k snatch.avi
133 This is a typical DVD ripping example; the input is a VOB file, the
134 output an AVI file with MPEG-4 video and MP3 audio. Note that in this
135 command we use B-frames so the MPEG-4 stream is DivX5 compatible, and
136 GOP size is 300 which means one intra frame every 10 seconds for 29.97fps
137 input video. Furthermore, the audio stream is MP3-encoded so you need
138 to enable LAME support by passing @code{--enable-libmp3lame} to configure.
139 The mapping is particularly useful for DVD transcoding
140 to get the desired audio language.
142 NOTE: To see the supported input formats, use @code{ffmpeg -formats}.
144 * You can extract images from a video, or create a video from many images:
146 For extracting images from a video:
148 ffmpeg -i foo.avi -r 1 -s WxH -f image2 foo-%03d.jpeg
151 This will extract one video frame per second from the video and will
152 output them in files named @file{foo-001.jpeg}, @file{foo-002.jpeg},
153 etc. Images will be rescaled to fit the new WxH values.
155 If you want to extract just a limited number of frames, you can use the
156 above command in combination with the -vframes or -t option, or in
157 combination with -ss to start extracting from a certain point in time.
159 For creating a video from many images:
161 ffmpeg -f image2 -i foo-%03d.jpeg -r 12 -s WxH foo.avi
164 The syntax @code{foo-%03d.jpeg} specifies to use a decimal number
165 composed of three digits padded with zeroes to express the sequence
166 number. It is the same syntax supported by the C printf function, but
167 only formats accepting a normal integer are suitable.
169 * You can put many streams of the same type in the output:
172 ffmpeg -i test1.avi -i test2.avi -vcodec copy -acodec copy -vcodec copy -acodec copy test12.avi -newvideo -newaudio
175 In addition to the first video and audio streams, the resulting
176 output file @file{test12.avi} will contain the second video
177 and the second audio stream found in the input streams list.
179 The @code{-newvideo}, @code{-newaudio} and @code{-newsubtitle}
180 options have to be specified immediately after the name of the output
181 file to which you want to add them.
188 The generic syntax is:
191 @c man begin SYNOPSIS
192 ffmpeg [[infile options][@option{-i} @var{infile}]]... @{[outfile options] @var{outfile}@}...
195 @c man begin DESCRIPTION
196 As a general rule, options are applied to the next specified
197 file. Therefore, order is important, and you can have the same
198 option on the command line multiple times. Each occurrence is
199 then applied to the next input or output file.
201 * To set the video bitrate of the output file to 64kbit/s:
203 ffmpeg -i input.avi -b 64k output.avi
206 * To force the frame rate of the output file to 24 fps:
208 ffmpeg -i input.avi -r 24 output.avi
211 * To force the frame rate of the input file (valid for raw formats only)
212 to 1 fps and the frame rate of the output file to 24 fps:
214 ffmpeg -r 1 -i input.m2v -r 24 output.avi
217 The format option may be needed for raw input files.
219 By default, FFmpeg tries to convert as losslessly as possible: It
220 uses the same audio and video parameters for the outputs as the one
221 specified for the inputs.
226 @include fftools-common-opts.texi
228 @section Main options
235 @item -i @var{filename}
239 Overwrite output files.
241 @item -t @var{duration}
242 Restrict the transcoded/captured video sequence
243 to the duration specified in seconds.
244 @code{hh:mm:ss[.xxx]} syntax is also supported.
246 @item -fs @var{limit_size}
247 Set the file size limit.
249 @item -ss @var{position}
250 Seek to given time position in seconds.
251 @code{hh:mm:ss[.xxx]} syntax is also supported.
253 @item -itsoffset @var{offset}
254 Set the input time offset in seconds.
255 @code{[-]hh:mm:ss[.xxx]} syntax is also supported.
256 This option affects all the input files that follow it.
257 The offset is added to the timestamps of the input files.
258 Specifying a positive offset means that the corresponding
259 streams are delayed by 'offset' seconds.
261 @item -timestamp @var{time}
264 @item -metadata @var{key}=@var{value}
265 Set a metadata key/value pair.
267 For example, for setting the title in the output file:
269 ffmpeg -i in.avi -metadata title="my title" out.flv
272 @item -v @var{number}
273 Set the logging verbosity level.
275 @item -target @var{type}
276 Specify target file type ("vcd", "svcd", "dvd", "dv", "dv50", "pal-vcd",
277 "ntsc-svcd", ... ). All the format options (bitrate, codecs,
278 buffer sizes) are then set automatically. You can just type:
281 ffmpeg -i myfile.avi -target vcd /tmp/vcd.mpg
284 Nevertheless you can specify additional options as long as you know
285 they do not conflict with the standard, as in:
288 ffmpeg -i myfile.avi -target vcd -bf 2 /tmp/vcd.mpg
291 @item -dframes @var{number}
292 Set the number of data frames to record.
294 @item -scodec @var{codec}
295 Force subtitle codec ('copy' to copy stream).
298 Add a new subtitle stream to the current output stream.
300 @item -slang @var{code}
301 Set the ISO 639 language code (3 letters) of the current subtitle stream.
305 @section Video Options
308 @item -b @var{bitrate}
309 Set the video bitrate in bit/s (default = 200 kb/s).
310 @item -vframes @var{number}
311 Set the number of video frames to record.
313 Set frame rate (Hz value, fraction or abbreviation), (default = 25).
315 Set frame size. The format is @samp{wxh} (ffserver default = 160x128, ffmpeg default = same as source).
316 The following abbreviations are recognized:
378 @item -aspect @var{aspect}
379 Set aspect ratio (4:3, 16:9 or 1.3333, 1.7777).
380 @item -croptop @var{size}
381 Set top crop band size (in pixels).
382 @item -cropbottom @var{size}
383 Set bottom crop band size (in pixels).
384 @item -cropleft @var{size}
385 Set left crop band size (in pixels).
386 @item -cropright @var{size}
387 Set right crop band size (in pixels).
388 @item -padtop @var{size}
389 Set top pad band size (in pixels).
390 @item -padbottom @var{size}
391 Set bottom pad band size (in pixels).
392 @item -padleft @var{size}
393 Set left pad band size (in pixels).
394 @item -padright @var{size}
395 Set right pad band size (in pixels).
396 @item -padcolor @var{hex_color}
397 Set color of padded bands. The value for padcolor is expressed
398 as a six digit hexadecimal number where the first two digits
399 represent red, the middle two digits green and last two digits
400 blue (default = 000000 (black)).
402 Disable video recording.
403 @item -bt @var{tolerance}
404 Set video bitrate tolerance (in bits, default 4000k).
405 Has a minimum value of: (target_bitrate/target_framerate).
406 In 1-pass mode, bitrate tolerance specifies how far ratecontrol is
407 willing to deviate from the target average bitrate value. This is
408 not related to min/max bitrate. Lowering tolerance too much has
409 an adverse effect on quality.
410 @item -maxrate @var{bitrate}
411 Set max video bitrate (in bit/s).
412 Requires -bufsize to be set.
413 @item -minrate @var{bitrate}
414 Set min video bitrate (in bit/s).
415 Most useful in setting up a CBR encode:
417 ffmpeg -i myfile.avi -b 4000k -minrate 4000k -maxrate 4000k -bufsize 1835k out.m2v
419 It is of little use elsewise.
420 @item -bufsize @var{size}
421 Set video buffer verifier buffer size (in bits).
422 @item -vcodec @var{codec}
423 Force video codec to @var{codec}. Use the @code{copy} special value to
424 tell that the raw codec data must be copied as is.
426 Use same video quality as source (implies VBR).
429 Select the pass number (1 or 2). It is used to do two-pass
430 video encoding. The statistics of the video are recorded in the first
431 pass into a log file (see also the option -passlogfile),
432 and in the second pass that log file is used to generate the video
433 at the exact requested bitrate.
434 On pass 1, you may just deactivate audio and set output to null,
435 examples for Windows and Unix:
437 ffmpeg -i foo.mov -vcodec libxvid -pass 1 -an -f rawvideo -y NUL
438 ffmpeg -i foo.mov -vcodec libxvid -pass 1 -an -f rawvideo -y /dev/null
441 @item -passlogfile @var{prefix}
442 Set two-pass log file name prefix to @var{prefix}, the default file name
443 prefix is ``ffmpeg2pass''. The complete file name will be
444 @file{PREFIX-N.log}, where N is a number specific to the output
448 Add a new video stream to the current output stream.
450 @item -vlang @var{code}
451 Set the ISO 639 language code (3 letters) of the current video stream.
455 @section Advanced Video Options
458 @item -pix_fmt @var{format}
459 Set pixel format. Use 'list' as parameter to show all the supported
461 @item -sws_flags @var{flags}
463 @item -g @var{gop_size}
464 Set the group of pictures size.
466 Use only intra frames.
469 @item -qscale @var{q}
470 Use fixed video quantizer scale (VBR).
472 minimum video quantizer scale (VBR)
474 maximum video quantizer scale (VBR)
476 maximum difference between the quantizer scales (VBR)
477 @item -qblur @var{blur}
478 video quantizer scale blur (VBR) (range 0.0 - 1.0)
479 @item -qcomp @var{compression}
480 video quantizer scale compression (VBR) (default 0.5).
481 Constant of ratecontrol equation. Recommended range for default rc_eq: 0.0-1.0
483 @item -lmin @var{lambda}
484 minimum video lagrange factor (VBR)
485 @item -lmax @var{lambda}
486 max video lagrange factor (VBR)
487 @item -mblmin @var{lambda}
488 minimum macroblock quantizer scale (VBR)
489 @item -mblmax @var{lambda}
490 maximum macroblock quantizer scale (VBR)
492 These four options (lmin, lmax, mblmin, mblmax) use 'lambda' units,
493 but you may use the QP2LAMBDA constant to easily convert from 'q' units:
495 ffmpeg -i src.ext -lmax 21*QP2LAMBDA dst.ext
498 @item -rc_init_cplx @var{complexity}
499 initial complexity for single pass encoding
500 @item -b_qfactor @var{factor}
501 qp factor between P- and B-frames
502 @item -i_qfactor @var{factor}
503 qp factor between P- and I-frames
504 @item -b_qoffset @var{offset}
505 qp offset between P- and B-frames
506 @item -i_qoffset @var{offset}
507 qp offset between P- and I-frames
508 @item -rc_eq @var{equation}
509 Set rate control equation (@pxref{FFmpeg formula
510 evaluator}) (default = @code{tex^qComp}).
511 @item -rc_override @var{override}
512 rate control override for specific intervals
513 @item -me_method @var{method}
514 Set motion estimation method to @var{method}.
515 Available methods are (from lowest to best quality):
518 Try just the (0, 0) vector.
527 exhaustive search (slow and marginally better than epzs)
530 @item -dct_algo @var{algo}
531 Set DCT algorithm to @var{algo}. Available values are:
534 FF_DCT_AUTO (default)
547 @item -idct_algo @var{algo}
548 Set IDCT algorithm to @var{algo}. Available values are:
551 FF_IDCT_AUTO (default)
575 Set error resilience to @var{n}.
578 FF_ER_CAREFUL (default)
584 FF_ER_VERY_AGGRESSIVE
587 @item -ec @var{bit_mask}
588 Set error concealment to @var{bit_mask}. @var{bit_mask} is a bit mask of
589 the following values:
592 FF_EC_GUESS_MVS (default = enabled)
594 FF_EC_DEBLOCK (default = enabled)
597 @item -bf @var{frames}
598 Use 'frames' B-frames (supported for MPEG-1, MPEG-2 and MPEG-4).
599 @item -mbd @var{mode}
603 FF_MB_DECISION_SIMPLE: Use mb_cmp (cannot change it yet in FFmpeg).
605 FF_MB_DECISION_BITS: Choose the one which needs the fewest bits.
607 FF_MB_DECISION_RD: rate distortion
611 Use four motion vector by macroblock (MPEG-4 only).
613 Use data partitioning (MPEG-4 only).
614 @item -bug @var{param}
615 Work around encoder bugs that are not auto-detected.
616 @item -strict @var{strictness}
617 How strictly to follow the standards.
619 Enable Advanced intra coding (h263+).
621 Enable Unlimited Motion Vector (h263+)
624 Deinterlace pictures.
626 Force interlacing support in encoder (MPEG-2 and MPEG-4 only).
627 Use this option if your input file is interlaced and you want
628 to keep the interlaced format for minimum losses.
629 The alternative is to deinterlace the input stream with
630 @option{-deinterlace}, but deinterlacing introduces losses.
632 Calculate PSNR of compressed frames.
634 Dump video coding statistics to @file{vstats_HHMMSS.log}.
635 @item -vstats_file @var{file}
636 Dump video coding statistics to @var{file}.
638 top=1/bottom=0/auto=-1 field first
639 @item -dc @var{precision}
641 @item -vtag @var{fourcc/tag}
642 Force video tag/fourcc.
645 @item -vbsf @var{bitstream_filter}
646 Bitstream filters available are "dump_extra", "remove_extra", "noise", "h264_mp4toannexb", "imxdump", "mjpegadump".
648 ffmpeg -i h264.mp4 -vcodec copy -vbsf h264_mp4toannexb -an out.h264
652 @section Audio Options
655 @item -aframes @var{number}
656 Set the number of audio frames to record.
658 Set the audio sampling frequency (default = 44100 Hz).
659 @item -ab @var{bitrate}
660 Set the audio bitrate in bit/s (default = 64k).
662 Set the audio quality (codec-specific, VBR).
663 @item -ac @var{channels}
664 Set the number of audio channels (default = 1).
666 Disable audio recording.
667 @item -acodec @var{codec}
668 Force audio codec to @var{codec}. Use the @code{copy} special value to
669 specify that the raw codec data must be copied as is.
671 Add a new audio track to the output file. If you want to specify parameters,
672 do so before @code{-newaudio} (@code{-acodec}, @code{-ab}, etc..).
674 Mapping will be done automatically, if the number of output streams is equal to
675 the number of input streams, else it will pick the first one that matches. You
676 can override the mapping using @code{-map} as usual.
680 ffmpeg -i file.mpg -vcodec copy -acodec ac3 -ab 384k test.mpg -acodec mp2 -ab 192k -newaudio
682 @item -alang @var{code}
683 Set the ISO 639 language code (3 letters) of the current audio stream.
686 @section Advanced Audio options:
689 @item -atag @var{fourcc/tag}
690 Force audio tag/fourcc.
691 @item -absf @var{bitstream_filter}
692 Bitstream filters available are "dump_extra", "remove_extra", "noise", "mp3comp", "mp3decomp".
695 @section Subtitle options:
698 @item -scodec @var{codec}
699 Force subtitle codec ('copy' to copy stream).
701 Add a new subtitle stream to the current output stream.
702 @item -slang @var{code}
703 Set the ISO 639 language code (3 letters) of the current subtitle stream.
705 Disable subtitle recording.
706 @item -sbsf @var{bitstream_filter}
707 Bitstream filters available are "mov2textsub", "text2movsub".
709 ffmpeg -i file.mov -an -vn -sbsf mov2textsub -scodec copy -f rawvideo sub.txt
713 @section Audio/Video grab options
716 @item -vc @var{channel}
717 Set video grab channel (DV1394 only).
718 @item -tvstd @var{standard}
719 Set television standard (NTSC, PAL (SECAM)).
721 Synchronize read on input.
724 @section Advanced options
727 @item -map @var{input_stream_id}[:@var{sync_stream_id}]
728 Set stream mapping from input streams to output streams.
729 Just enumerate the input streams in the order you want them in the output.
730 @var{sync_stream_id} if specified sets the input stream to sync
732 @item -map_meta_data @var{outfile}:@var{infile}
733 Set meta data information of @var{outfile} from @var{infile}.
735 Print specific debug info.
737 Show benchmarking information at the end of an encode.
738 Shows CPU time used and maximum memory consumption.
739 Maximum memory consumption is not supported on all systems,
740 it will usually display as 0 if not supported.
742 Dump each input packet.
744 When dumping packets, also dump the payload.
746 Only use bit exact algorithms (for codec testing).
748 Set RTP payload size in bytes.
750 Read input at native frame rate. Mainly used to simulate a grab device.
752 Loop over the input stream. Currently it works only for image
753 streams. This option is used for automatic FFserver testing.
754 @item -loop_output @var{number_of_times}
755 Repeatedly loop output for formats that support looping such as animated GIF
756 (0 will loop the output infinitely).
757 @item -threads @var{count}
759 @item -vsync @var{parameter}
761 0 Each frame is passed with its timestamp from the demuxer to the muxer
762 1 Frames will be duplicated and droped to achive exactly the requested
764 2 Frames are passed through with their timestamp or droped so as to prevent
765 2 frames having the same timestamp
766 -1 Chooses between 1 and 2 depending on muxer capabilities. This is default.
768 With -map you can select from
769 which stream the timestamps should be taken. You can leave either video or
770 audio unchanged and sync the remaining stream(s) to the unchanged one.
771 @item -async @var{samples_per_second}
772 Audio sync method. "Stretches/squeezes" the audio stream to match the timestamps,
773 the parameter is the maximum samples per second by which the audio is changed.
774 -async 1 is a special case where only the start of the audio stream is corrected
775 without any later correction.
777 Copy timestamps from input to output.
779 Finish encoding when the shortest input stream ends.
780 @item -dts_delta_threshold
781 Timestamp discontinuity delta threshold.
782 @item -muxdelay @var{seconds}
783 Set the maximum demux-decode delay.
784 @item -muxpreload @var{seconds}
785 Set the initial demux-decode delay.
788 @section Preset files
790 A preset file contains a sequence of @var{option}=@var{value} pairs,
791 one for each line, specifying a sequence of options which would be
792 awkward to specify on the command line. Lines starting with the hash
793 ('#') character are ignored and are used to provide comments. Check
794 the @file{ffpresets} directory in the FFmpeg source tree for examples.
796 Preset files are specified with the @code{vpre}, @code{apre},
797 @code{spre}, and @code{fpre} options. The @code{fpre} option takes the
798 filename of the preset instead of a preset name as input and can be
799 used for any kind of codec. For the @code{vpre}, @code{apre}, and
800 @code{spre} options, the options specified in a preset file are
801 applied to the currently selected codec of the same type as the preset
804 The argument passed to the @code{vpre}, @code{apre}, and @code{spre}
805 preset options identifies the preset file to use according to the
808 First ffmpeg searches for a file named @var{arg}.ffpreset in the
809 directories @file{$HOME/.ffmpeg}, and in the datadir defined at
810 configuration time (usually @file{PREFIX/share/ffmpeg}) in that
811 order. For example, if the argument is @code{libx264-max}, it will
812 search for the file @file{libx264-max.ffpreset}.
814 If no such file is found, then ffmpeg will search for a file named
815 @var{codec_name}-@var{arg}.ffpreset in the above-mentioned
816 directories, where @var{codec_name} is the name of the codec to which
817 the preset file options will be applied. For example, if you select
818 the video codec with @code{-vcodec libx264} and use @code{-vpre max},
819 then it will search for the file @file{libx264-max.ffpreset}.
821 @anchor{FFmpeg formula evaluator}
822 @section FFmpeg formula evaluator
824 When evaluating a rate control string, FFmpeg uses an internal formula
827 The following binary operators are available: @code{+}, @code{-},
828 @code{*}, @code{/}, @code{^}.
830 The following unary operators are available: @code{+}, @code{-},
833 The following statements are available: @code{ld}, @code{st},
836 The following functions are available:
864 The following constants are available:
893 @settitle FFmpeg video converter
896 ffserver(1), ffplay(1) and the HTML documentation of @file{ffmpeg}.
907 The file name can be @file{-} to read from standard input or to write
910 FFmpeg also handles many protocols specified with an URL syntax.
912 Use 'ffmpeg -protocols' to see a list of the supported protocols.
914 The protocol @code{http:} is currently used only to communicate with
915 FFserver (see the FFserver documentation). When FFmpeg will be a
916 video player it will also be used for streaming :-)
921 @item For streaming at very low bitrate application, use a low frame rate
922 and a small GOP size. This is especially true for RealVideo where
923 the Linux player does not seem to be very fast, so it can miss
924 frames. An example is:
927 ffmpeg -g 3 -r 3 -t 10 -b 50k -s qcif -f rv10 /tmp/b.rm
930 @item The parameter 'q' which is displayed while encoding is the current
931 quantizer. The value 1 indicates that a very good quality could
932 be achieved. The value 31 indicates the worst quality. If q=31 appears
933 too often, it means that the encoder cannot compress enough to meet
934 your bitrate. You must either increase the bitrate, decrease the
935 frame rate or decrease the frame size.
937 @item If your computer is not fast enough, you can speed up the
938 compression at the expense of the compression ratio. You can use
939 '-me zero' to speed up motion estimation, and '-intra' to disable
940 motion estimation completely (you have only I-frames, which means it
941 is about as good as JPEG compression).
943 @item To have very low audio bitrates, reduce the sampling frequency
944 (down to 22050 Hz for MPEG audio, 22050 or 11025 for AC-3).
946 @item To have a constant quality (but a variable bitrate), use the option
947 '-qscale n' when 'n' is between 1 (excellent quality) and 31 (worst
950 @item When converting video files, you can use the '-sameq' option which
951 uses the same quality factor in the encoder as in the decoder.
952 It allows almost lossless encoding.