1 \input texinfo @c -*- texinfo -*-
3 @settitle FFmpeg Documentation
6 @center @titlefont{FFmpeg Documentation}
11 @c man begin DESCRIPTION
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.
24 As a general rule, options are applied to the next specified
25 file. Therefore, order is important, and you can have the same
26 option on the command line multiple times. Each occurrence is
27 then applied to the next input or output file.
29 * To set the video bitrate of the output file to 64kbit/s:
31 ffmpeg -i input.avi -b 64k output.avi
34 * To force the frame rate of the output file to 24 fps:
36 ffmpeg -i input.avi -r 24 output.avi
39 * To force the frame rate of the input file (valid for raw formats only)
40 to 1 fps and the frame rate of the output file to 24 fps:
42 ffmpeg -r 1 -i input.m2v -r 24 output.avi
45 The format option may be needed for raw input files.
47 By default, FFmpeg tries to convert as losslessly as possible: It
48 uses the same audio and video parameters for the outputs as the one
49 specified for the inputs.
51 @c man end DESCRIPTION
56 @section Video and Audio grabbing
58 FFmpeg can grab video and audio from devices given that you specify the input
62 ffmpeg -f oss -i /dev/dsp -f video4linux2 -i /dev/video0 /tmp/out.mpg
65 Note that you must activate the right video source and channel before
66 launching FFmpeg with any TV viewer such as xawtv
67 (@url{http://linux.bytesex.org/xawtv/}) by Gerd Knorr. You also
68 have to set the audio recording levels correctly with a
73 FFmpeg can grab the X11 display.
76 ffmpeg -f x11grab -s cif -i :0.0 /tmp/out.mpg
79 0.0 is display.screen number of your X11 server, same as
80 the DISPLAY environment variable.
83 ffmpeg -f x11grab -s cif -i :0.0+10,20 /tmp/out.mpg
86 0.0 is display.screen number of your X11 server, same as the DISPLAY environment
87 variable. 10 is the x-offset and 20 the y-offset for the grabbing.
89 @section Video and Audio file format conversion
91 * FFmpeg can use any supported file format and protocol as input:
95 * You can use YUV files as input:
98 ffmpeg -i /tmp/test%d.Y /tmp/out.mpg
101 It will use the files:
103 /tmp/test0.Y, /tmp/test0.U, /tmp/test0.V,
104 /tmp/test1.Y, /tmp/test1.U, /tmp/test1.V, etc...
107 The Y files use twice the resolution of the U and V files. They are
108 raw files, without header. They can be generated by all decent video
109 decoders. You must specify the size of the image with the @option{-s} option
110 if FFmpeg cannot guess it.
112 * You can input from a raw YUV420P file:
115 ffmpeg -i /tmp/test.yuv /tmp/out.avi
118 test.yuv is a file containing raw YUV planar data. Each frame is composed
119 of the Y plane followed by the U and V planes at half vertical and
120 horizontal resolution.
122 * You can output to a raw YUV420P file:
125 ffmpeg -i mydivx.avi hugefile.yuv
128 * You can set several input files and output files:
131 ffmpeg -i /tmp/a.wav -s 640x480 -i /tmp/a.yuv /tmp/a.mpg
134 Converts the audio file a.wav and the raw YUV video file a.yuv
137 * You can also do audio and video conversions at the same time:
140 ffmpeg -i /tmp/a.wav -ar 22050 /tmp/a.mp2
143 Converts a.wav to MPEG audio at 22050 Hz sample rate.
145 * You can encode to several formats at the same time and define a
146 mapping from input stream to output streams:
149 ffmpeg -i /tmp/a.wav -ab 64k /tmp/a.mp2 -ab 128k /tmp/b.mp2 -map 0:0 -map 0:0
152 Converts a.wav to a.mp2 at 64 kbits and to b.mp2 at 128 kbits. '-map
153 file:index' specifies which input stream is used for each output
154 stream, in the order of the definition of output streams.
156 * You can transcode decrypted VOBs:
159 ffmpeg -i snatch_1.vob -f avi -vcodec mpeg4 -b 800k -g 300 -bf 2 -acodec libmp3lame -ab 128k snatch.avi
162 This is a typical DVD ripping example; the input is a VOB file, the
163 output an AVI file with MPEG-4 video and MP3 audio. Note that in this
164 command we use B-frames so the MPEG-4 stream is DivX5 compatible, and
165 GOP size is 300 which means one intra frame every 10 seconds for 29.97fps
166 input video. Furthermore, the audio stream is MP3-encoded so you need
167 to enable LAME support by passing @code{--enable-libmp3lame} to configure.
168 The mapping is particularly useful for DVD transcoding
169 to get the desired audio language.
171 NOTE: To see the supported input formats, use @code{ffmpeg -formats}.
173 * You can extract images from a video, or create a video from many images:
175 For extracting images from a video:
177 ffmpeg -i foo.avi -r 1 -s WxH -f image2 foo-%03d.jpeg
180 This will extract one video frame per second from the video and will
181 output them in files named @file{foo-001.jpeg}, @file{foo-002.jpeg},
182 etc. Images will be rescaled to fit the new WxH values.
184 If you want to extract just a limited number of frames, you can use the
185 above command in combination with the -vframes or -t option, or in
186 combination with -ss to start extracting from a certain point in time.
188 For creating a video from many images:
190 ffmpeg -f image2 -i foo-%03d.jpeg -r 12 -s WxH foo.avi
193 The syntax @code{foo-%03d.jpeg} specifies to use a decimal number
194 composed of three digits padded with zeroes to express the sequence
195 number. It is the same syntax supported by the C printf function, but
196 only formats accepting a normal integer are suitable.
198 * You can put many streams of the same type in the output:
201 ffmpeg -i test1.avi -i test2.avi -vcodec copy -acodec copy -vcodec copy -acodec copy test12.avi -newvideo -newaudio
204 In addition to the first video and audio streams, the resulting
205 output file @file{test12.avi} will contain the second video
206 and the second audio stream found in the input streams list.
208 The @code{-newvideo}, @code{-newaudio} and @code{-newsubtitle}
209 options have to be specified immediately after the name of the output
210 file to which you want to add them.
217 The generic syntax is:
220 @c man begin SYNOPSIS
221 ffmpeg [[infile options][@option{-i} @var{infile}]]... @{[outfile options] @var{outfile}@}...
227 @include fftools-common-opts.texi
229 @section Main options
236 @item -i @var{filename}
240 Overwrite output files.
242 @item -t @var{duration}
243 Restrict the transcoded/captured video sequence
244 to the duration specified in seconds.
245 @code{hh:mm:ss[.xxx]} syntax is also supported.
247 @item -fs @var{limit_size}
248 Set the file size limit.
250 @item -ss @var{position}
251 Seek to given time position in seconds.
252 @code{hh:mm:ss[.xxx]} syntax is also supported.
254 @item -itsoffset @var{offset}
255 Set the input time offset in seconds.
256 @code{[-]hh:mm:ss[.xxx]} syntax is also supported.
257 This option affects all the input files that follow it.
258 The offset is added to the timestamps of the input files.
259 Specifying a positive offset means that the corresponding
260 streams are delayed by 'offset' seconds.
262 @item -timestamp @var{time}
265 @item -metadata @var{key}=@var{value}
266 Set a metadata key/value pair.
268 For example, for setting the title in the output file:
270 ffmpeg -i in.avi -metadata title="my title" out.flv
273 @item -v @var{number}
274 Set the logging verbosity level.
276 @item -target @var{type}
277 Specify target file type ("vcd", "svcd", "dvd", "dv", "dv50", "pal-vcd",
278 "ntsc-svcd", ... ). All the format options (bitrate, codecs,
279 buffer sizes) are then set automatically. You can just type:
282 ffmpeg -i myfile.avi -target vcd /tmp/vcd.mpg
285 Nevertheless you can specify additional options as long as you know
286 they do not conflict with the standard, as in:
289 ffmpeg -i myfile.avi -target vcd -bf 2 /tmp/vcd.mpg
292 @item -dframes @var{number}
293 Set the number of data frames to record.
295 @item -scodec @var{codec}
296 Force subtitle codec ('copy' to copy stream).
299 Add a new subtitle stream to the current output stream.
301 @item -slang @var{code}
302 Set the ISO 639 language code (3 letters) of the current subtitle stream.
306 @section Video Options
309 @item -b @var{bitrate}
310 Set the video bitrate in bit/s (default = 200 kb/s).
311 @item -vframes @var{number}
312 Set the number of video frames to record.
314 Set frame rate (Hz value, fraction or abbreviation), (default = 25).
316 Set frame size. The format is @samp{wxh} (ffserver default = 160x128, ffmpeg default = same as source).
317 The following abbreviations are recognized:
379 @item -aspect @var{aspect}
380 Set aspect ratio (4:3, 16:9 or 1.3333, 1.7777).
381 @item -croptop @var{size}
382 Set top crop band size (in pixels).
383 @item -cropbottom @var{size}
384 Set bottom crop band size (in pixels).
385 @item -cropleft @var{size}
386 Set left crop band size (in pixels).
387 @item -cropright @var{size}
388 Set right crop band size (in pixels).
389 @item -padtop @var{size}
390 Set top pad band size (in pixels).
391 @item -padbottom @var{size}
392 Set bottom pad band size (in pixels).
393 @item -padleft @var{size}
394 Set left pad band size (in pixels).
395 @item -padright @var{size}
396 Set right pad band size (in pixels).
397 @item -padcolor @var{hex_color}
398 Set color of padded bands. The value for padcolor is expressed
399 as a six digit hexadecimal number where the first two digits
400 represent red, the middle two digits green and last two digits
401 blue (default = 000000 (black)).
403 Disable video recording.
404 @item -bt @var{tolerance}
405 Set video bitrate tolerance (in bits, default 4000k).
406 Has a minimum value of: (target_bitrate/target_framerate).
407 In 1-pass mode, bitrate tolerance specifies how far ratecontrol is
408 willing to deviate from the target average bitrate value. This is
409 not related to min/max bitrate. Lowering tolerance too much has
410 an adverse effect on quality.
411 @item -maxrate @var{bitrate}
412 Set max video bitrate (in bit/s).
413 Requires -bufsize to be set.
414 @item -minrate @var{bitrate}
415 Set min video bitrate (in bit/s).
416 Most useful in setting up a CBR encode:
418 ffmpeg -i myfile.avi -b 4000k -minrate 4000k -maxrate 4000k -bufsize 1835k out.m2v
420 It is of little use elsewise.
421 @item -bufsize @var{size}
422 Set video buffer verifier buffer size (in bits).
423 @item -vcodec @var{codec}
424 Force video codec to @var{codec}. Use the @code{copy} special value to
425 tell that the raw codec data must be copied as is.
427 Use same video quality as source (implies VBR).
430 Select the pass number (1 or 2). It is used to do two-pass
431 video encoding. The statistics of the video are recorded in the first
432 pass into a log file (see also the option -passlogfile),
433 and in the second pass that log file is used to generate the video
434 at the exact requested bitrate.
435 On pass 1, you may just deactivate audio and set output to null,
436 examples for Windows and Unix:
438 ffmpeg -i foo.mov -vcodec libxvid -pass 1 -an -f rawvideo -y NUL
439 ffmpeg -i foo.mov -vcodec libxvid -pass 1 -an -f rawvideo -y /dev/null
442 @item -passlogfile @var{prefix}
443 Set two-pass log file name prefix to @var{prefix}, the default file name
444 prefix is ``ffmpeg2pass''. The complete file name will be
445 @file{PREFIX-N.log}, where N is a number specific to the output
449 Add a new video stream to the current output stream.
451 @item -vlang @var{code}
452 Set the ISO 639 language code (3 letters) of the current video stream.
456 @section Advanced Video Options
459 @item -pix_fmt @var{format}
460 Set pixel format. Use 'list' as parameter to show all the supported
462 @item -sws_flags @var{flags}
464 @item -g @var{gop_size}
465 Set the group of pictures size.
467 Use only intra frames.
470 @item -qscale @var{q}
471 Use fixed video quantizer scale (VBR).
473 minimum video quantizer scale (VBR)
475 maximum video quantizer scale (VBR)
477 maximum difference between the quantizer scales (VBR)
478 @item -qblur @var{blur}
479 video quantizer scale blur (VBR) (range 0.0 - 1.0)
480 @item -qcomp @var{compression}
481 video quantizer scale compression (VBR) (default 0.5).
482 Constant of ratecontrol equation. Recommended range for default rc_eq: 0.0-1.0
484 @item -lmin @var{lambda}
485 minimum video lagrange factor (VBR)
486 @item -lmax @var{lambda}
487 max video lagrange factor (VBR)
488 @item -mblmin @var{lambda}
489 minimum macroblock quantizer scale (VBR)
490 @item -mblmax @var{lambda}
491 maximum macroblock quantizer scale (VBR)
493 These four options (lmin, lmax, mblmin, mblmax) use 'lambda' units,
494 but you may use the QP2LAMBDA constant to easily convert from 'q' units:
496 ffmpeg -i src.ext -lmax 21*QP2LAMBDA dst.ext
499 @item -rc_init_cplx @var{complexity}
500 initial complexity for single pass encoding
501 @item -b_qfactor @var{factor}
502 qp factor between P- and B-frames
503 @item -i_qfactor @var{factor}
504 qp factor between P- and I-frames
505 @item -b_qoffset @var{offset}
506 qp offset between P- and B-frames
507 @item -i_qoffset @var{offset}
508 qp offset between P- and I-frames
509 @item -rc_eq @var{equation}
510 Set rate control equation (@pxref{FFmpeg formula
511 evaluator}) (default = @code{tex^qComp}).
512 @item -rc_override @var{override}
513 rate control override for specific intervals
514 @item -me_method @var{method}
515 Set motion estimation method to @var{method}.
516 Available methods are (from lowest to best quality):
519 Try just the (0, 0) vector.
528 exhaustive search (slow and marginally better than epzs)
531 @item -dct_algo @var{algo}
532 Set DCT algorithm to @var{algo}. Available values are:
535 FF_DCT_AUTO (default)
548 @item -idct_algo @var{algo}
549 Set IDCT algorithm to @var{algo}. Available values are:
552 FF_IDCT_AUTO (default)
576 Set error resilience to @var{n}.
579 FF_ER_CAREFUL (default)
585 FF_ER_VERY_AGGRESSIVE
588 @item -ec @var{bit_mask}
589 Set error concealment to @var{bit_mask}. @var{bit_mask} is a bit mask of
590 the following values:
593 FF_EC_GUESS_MVS (default = enabled)
595 FF_EC_DEBLOCK (default = enabled)
598 @item -bf @var{frames}
599 Use 'frames' B-frames (supported for MPEG-1, MPEG-2 and MPEG-4).
600 @item -mbd @var{mode}
604 FF_MB_DECISION_SIMPLE: Use mb_cmp (cannot change it yet in FFmpeg).
606 FF_MB_DECISION_BITS: Choose the one which needs the fewest bits.
608 FF_MB_DECISION_RD: rate distortion
612 Use four motion vector by macroblock (MPEG-4 only).
614 Use data partitioning (MPEG-4 only).
615 @item -bug @var{param}
616 Work around encoder bugs that are not auto-detected.
617 @item -strict @var{strictness}
618 How strictly to follow the standards.
620 Enable Advanced intra coding (h263+).
622 Enable Unlimited Motion Vector (h263+)
625 Deinterlace pictures.
627 Force interlacing support in encoder (MPEG-2 and MPEG-4 only).
628 Use this option if your input file is interlaced and you want
629 to keep the interlaced format for minimum losses.
630 The alternative is to deinterlace the input stream with
631 @option{-deinterlace}, but deinterlacing introduces losses.
633 Calculate PSNR of compressed frames.
635 Dump video coding statistics to @file{vstats_HHMMSS.log}.
636 @item -vstats_file @var{file}
637 Dump video coding statistics to @var{file}.
639 top=1/bottom=0/auto=-1 field first
640 @item -dc @var{precision}
642 @item -vtag @var{fourcc/tag}
643 Force video tag/fourcc.
646 @item -vbsf @var{bitstream_filter}
647 Bitstream filters available are "dump_extra", "remove_extra", "noise", "h264_mp4toannexb", "imxdump", "mjpegadump".
649 ffmpeg -i h264.mp4 -vcodec copy -vbsf h264_mp4toannexb -an out.h264
653 @section Audio Options
656 @item -aframes @var{number}
657 Set the number of audio frames to record.
659 Set the audio sampling frequency (default = 44100 Hz).
660 @item -ab @var{bitrate}
661 Set the audio bitrate in bit/s (default = 64k).
663 Set the audio quality (codec-specific, VBR).
664 @item -ac @var{channels}
665 Set the number of audio channels (default = 1).
667 Disable audio recording.
668 @item -acodec @var{codec}
669 Force audio codec to @var{codec}. Use the @code{copy} special value to
670 specify that the raw codec data must be copied as is.
672 Add a new audio track to the output file. If you want to specify parameters,
673 do so before @code{-newaudio} (@code{-acodec}, @code{-ab}, etc..).
675 Mapping will be done automatically, if the number of output streams is equal to
676 the number of input streams, else it will pick the first one that matches. You
677 can override the mapping using @code{-map} as usual.
681 ffmpeg -i file.mpg -vcodec copy -acodec ac3 -ab 384k test.mpg -acodec mp2 -ab 192k -newaudio
683 @item -alang @var{code}
684 Set the ISO 639 language code (3 letters) of the current audio stream.
687 @section Advanced Audio options:
690 @item -atag @var{fourcc/tag}
691 Force audio tag/fourcc.
692 @item -absf @var{bitstream_filter}
693 Bitstream filters available are "dump_extra", "remove_extra", "noise", "mp3comp", "mp3decomp".
696 @section Subtitle options:
699 @item -scodec @var{codec}
700 Force subtitle codec ('copy' to copy stream).
702 Add a new subtitle stream to the current output stream.
703 @item -slang @var{code}
704 Set the ISO 639 language code (3 letters) of the current subtitle stream.
706 Disable subtitle recording.
707 @item -sbsf @var{bitstream_filter}
708 Bitstream filters available are "mov2textsub", "text2movsub".
710 ffmpeg -i file.mov -an -vn -sbsf mov2textsub -scodec copy -f rawvideo sub.txt
714 @section Audio/Video grab options
717 @item -vc @var{channel}
718 Set video grab channel (DV1394 only).
719 @item -tvstd @var{standard}
720 Set television standard (NTSC, PAL (SECAM)).
722 Synchronize read on input.
725 @section Advanced options
728 @item -map @var{input_stream_id}[:@var{sync_stream_id}]
729 Set stream mapping from input streams to output streams.
730 Just enumerate the input streams in the order you want them in the output.
731 @var{sync_stream_id} if specified sets the input stream to sync
733 @item -map_meta_data @var{outfile}:@var{infile}
734 Set meta data information of @var{outfile} from @var{infile}.
736 Print specific debug info.
738 Show benchmarking information at the end of an encode.
739 Shows CPU time used and maximum memory consumption.
740 Maximum memory consumption is not supported on all systems,
741 it will usually display as 0 if not supported.
743 Dump each input packet.
745 When dumping packets, also dump the payload.
747 Only use bit exact algorithms (for codec testing).
749 Set RTP payload size in bytes.
751 Read input at native frame rate. Mainly used to simulate a grab device.
753 Loop over the input stream. Currently it works only for image
754 streams. This option is used for automatic FFserver testing.
755 @item -loop_output @var{number_of_times}
756 Repeatedly loop output for formats that support looping such as animated GIF
757 (0 will loop the output infinitely).
758 @item -threads @var{count}
760 @item -vsync @var{parameter}
762 0 Each frame is passed with its timestamp from the demuxer to the muxer
763 1 Frames will be duplicated and dropped to achieve exactly the requested
765 2 Frames are passed through with their timestamp or dropped so as to prevent
766 2 frames from having the same timestamp
767 -1 Chooses between 1 and 2 depending on muxer capabilities. This is the default method.
769 With -map you can select from
770 which stream the timestamps should be taken. You can leave either video or
771 audio unchanged and sync the remaining stream(s) to the unchanged one.
772 @item -async @var{samples_per_second}
773 Audio sync method. "Stretches/squeezes" the audio stream to match the timestamps,
774 the parameter is the maximum samples per second by which the audio is changed.
775 -async 1 is a special case where only the start of the audio stream is corrected
776 without any later correction.
778 Copy timestamps from input to output.
780 Finish encoding when the shortest input stream ends.
781 @item -dts_delta_threshold
782 Timestamp discontinuity delta threshold.
783 @item -muxdelay @var{seconds}
784 Set the maximum demux-decode delay.
785 @item -muxpreload @var{seconds}
786 Set the initial demux-decode delay.
789 @section Preset files
791 A preset file contains a sequence of @var{option}=@var{value} pairs,
792 one for each line, specifying a sequence of options which would be
793 awkward to specify on the command line. Lines starting with the hash
794 ('#') character are ignored and are used to provide comments. Check
795 the @file{ffpresets} directory in the FFmpeg source tree for examples.
797 Preset files are specified with the @code{vpre}, @code{apre},
798 @code{spre}, and @code{fpre} options. The @code{fpre} option takes the
799 filename of the preset instead of a preset name as input and can be
800 used for any kind of codec. For the @code{vpre}, @code{apre}, and
801 @code{spre} options, the options specified in a preset file are
802 applied to the currently selected codec of the same type as the preset
805 The argument passed to the @code{vpre}, @code{apre}, and @code{spre}
806 preset options identifies the preset file to use according to the
809 First ffmpeg searches for a file named @var{arg}.ffpreset in the
810 directories @file{$FFMPEG_DATADIR} (if set), and @file{$HOME/.ffmpeg}, and in
811 the datadir defined at configuration time (usually @file{PREFIX/share/ffmpeg})
812 in that order. For example, if the argument is @code{libx264-max}, it will
813 search for the file @file{libx264-max.ffpreset}.
815 If no such file is found, then ffmpeg will search for a file named
816 @var{codec_name}-@var{arg}.ffpreset in the above-mentioned
817 directories, where @var{codec_name} is the name of the codec to which
818 the preset file options will be applied. For example, if you select
819 the video codec with @code{-vcodec libx264} and use @code{-vpre max},
820 then it will search for the file @file{libx264-max.ffpreset}.
822 @anchor{FFmpeg formula evaluator}
823 @section FFmpeg formula evaluator
825 When evaluating a rate control string, FFmpeg uses an internal formula
828 The following binary operators are available: @code{+}, @code{-},
829 @code{*}, @code{/}, @code{^}.
831 The following unary operators are available: @code{+}, @code{-},
834 The following statements are available: @code{ld}, @code{st},
837 The following functions are available:
865 The following constants are available:
894 @settitle FFmpeg video converter
897 ffserver(1), ffplay(1) and the HTML documentation of @file{ffmpeg}.
908 The file name can be @file{-} to read from standard input or to write
911 FFmpeg also handles many protocols specified with an URL syntax.
913 Use 'ffmpeg -protocols' to see a list of the supported protocols.
915 The protocol @code{http:} is currently used only to communicate with
916 FFserver (see the FFserver documentation). When FFmpeg will be a
917 video player it will also be used for streaming :-)
924 For streaming at very low bitrate application, use a low frame rate
925 and a small GOP size. This is especially true for RealVideo where
926 the Linux player does not seem to be very fast, so it can miss
927 frames. An example is:
930 ffmpeg -g 3 -r 3 -t 10 -b 50k -s qcif -f rv10 /tmp/b.rm
934 The parameter 'q' which is displayed while encoding is the current
935 quantizer. The value 1 indicates that a very good quality could
936 be achieved. The value 31 indicates the worst quality. If q=31 appears
937 too often, it means that the encoder cannot compress enough to meet
938 your bitrate. You must either increase the bitrate, decrease the
939 frame rate or decrease the frame size.
942 If your computer is not fast enough, you can speed up the
943 compression at the expense of the compression ratio. You can use
944 '-me zero' to speed up motion estimation, and '-intra' to disable
945 motion estimation completely (you have only I-frames, which means it
946 is about as good as JPEG compression).
949 To have very low audio bitrates, reduce the sampling frequency
950 (down to 22050 Hz for MPEG audio, 22050 or 11025 for AC-3).
953 To have a constant quality (but a variable bitrate), use the option
954 '-qscale n' when 'n' is between 1 (excellent quality) and 31 (worst
958 When converting video files, you can use the '-sameq' option which
959 uses the same quality factor in the encoder as in the decoder.
960 It allows almost lossless encoding.