1 \input texinfo @c -*- texinfo -*-
3 @settitle ffmpeg Documentation
5 @center @titlefont{ffmpeg Documentation}
14 The generic syntax is:
18 ffmpeg [global options] [[infile options][@option{-i} @var{infile}]]... @{[outfile options] @var{outfile}@}...
23 @c man begin DESCRIPTION
25 ffmpeg is a very fast video and audio converter that can also grab from
26 a live audio/video source. It can also convert between arbitrary sample
27 rates and resize video on the fly with a high quality polyphase filter.
29 ffmpeg reads from an arbitrary number of input "files" (which can be regular
30 files, pipes, network streams, grabbing devices, etc.), specified by the
31 @code{-i} option, and writes to an arbitrary number of output "files", which are
32 specified by a plain output filename. Anything found on the command line which
33 cannot be interpreted as an option is considered to be an output filename.
35 Each input or output file can in principle contain any number of streams of
36 different types (video/audio/subtitle/attachment/data). Allowed number and/or
37 types of streams can be limited by the container format. Selecting, which
38 streams from which inputs go into output, is done either automatically or with
39 the @code{-map} option (see the Stream selection chapter).
41 To refer to input files in options, you must use their indices (0-based). E.g.
42 the first input file is @code{0}, the second is @code{1} etc. Similarly, streams
43 within a file are referred to by their indices. E.g. @code{2:3} refers to the
44 fourth stream in the third input file. See also the Stream specifiers chapter.
46 As a general rule, options are applied to the next specified
47 file. Therefore, order is important, and you can have the same
48 option on the command line multiple times. Each occurrence is
49 then applied to the next input or output file.
50 Exceptions from this rule are the global options (e.g. verbosity level),
51 which should be specified first.
53 Do not mix input and output files -- first specify all input files, then all
54 output files. Also do not mix options which belong to different files. All
55 options apply ONLY to the next input or output file and are reset between files.
59 To set the video bitrate of the output file to 64kbit/s:
61 ffmpeg -i input.avi -b:v 64k output.avi
65 To force the frame rate of the output file to 24 fps:
67 ffmpeg -i input.avi -r 24 output.avi
71 To force the frame rate of the input file (valid for raw formats only)
72 to 1 fps and the frame rate of the output file to 24 fps:
74 ffmpeg -r 1 -i input.m2v -r 24 output.avi
78 The format option may be needed for raw input files.
80 @c man end DESCRIPTION
82 @chapter Stream selection
83 @c man begin STREAM SELECTION
85 By default ffmpeg includes only one stream of each type (video, audio, subtitle)
86 present in the input files and adds them to each output file. It picks the
87 "best" of each based upon the following criteria; for video it is the stream
88 with the highest resolution, for audio the stream with the most channels, for
89 subtitle it's the first subtitle stream. In the case where several streams of
90 the same type rate equally, the lowest numbered stream is chosen.
92 You can disable some of those defaults by using @code{-vn/-an/-sn} options. For
93 full manual control, use the @code{-map} option, which disables the defaults just
96 @c man end STREAM SELECTION
101 @include avtools-common-opts.texi
103 @section Main options
107 @item -f @var{fmt} (@emph{input/output})
108 Force input or output file format. The format is normally auto detected for input
109 files and guessed from file extension for output files, so this option is not
110 needed in most cases.
112 @item -i @var{filename} (@emph{input})
115 @item -y (@emph{global})
116 Overwrite output files without asking.
118 @item -n (@emph{global})
119 Do not overwrite output files but exit if file exists.
121 @item -c[:@var{stream_specifier}] @var{codec} (@emph{input/output,per-stream})
122 @itemx -codec[:@var{stream_specifier}] @var{codec} (@emph{input/output,per-stream})
123 Select an encoder (when used before an output file) or a decoder (when used
124 before an input file) for one or more streams. @var{codec} is the name of a
125 decoder/encoder or a special value @code{copy} (output only) to indicate that
126 the stream is not to be re-encoded.
130 ffmpeg -i INPUT -map 0 -c:v libx264 -c:a copy OUTPUT
132 encodes all video streams with libx264 and copies all audio streams.
134 For each stream, the last matching @code{c} option is applied, so
136 ffmpeg -i INPUT -map 0 -c copy -c:v:1 libx264 -c:a:137 libvorbis OUTPUT
138 will copy all the streams except the second video, which will be encoded with
139 libx264, and the 138th audio, which will be encoded with libvorbis.
141 @item -t @var{duration} (@emph{output})
142 Stop writing the output after its duration reaches @var{duration}.
143 @var{duration} may be a number in seconds, or in @code{hh:mm:ss[.xxx]} form.
145 @item -fs @var{limit_size} (@emph{output})
146 Set the file size limit, expressed in bytes.
148 @item -ss @var{position} (@emph{input/output})
149 When used as an input option (before @code{-i}), seeks in this input file to
150 @var{position}. When used as an output option (before an output filename),
151 decodes but discards input until the timestamps reach @var{position}. This is
152 slower, but more accurate.
154 @var{position} may be either in seconds or in @code{hh:mm:ss[.xxx]} form.
156 @item -itsoffset @var{offset} (@emph{input})
157 Set the input time offset in seconds.
158 @code{[-]hh:mm:ss[.xxx]} syntax is also supported.
159 The offset is added to the timestamps of the input files.
160 Specifying a positive offset means that the corresponding
161 streams are delayed by @var{offset} seconds.
163 @item -timestamp @var{time} (@emph{output})
164 Set the recording timestamp in the container.
165 The syntax for @var{time} is:
167 now|([(YYYY-MM-DD|YYYYMMDD)[T|t| ]]((HH[:MM[:SS[.m...]]])|(HH[MM[SS[.m...]]]))[Z|z])
169 If the value is "now" it takes the current time.
170 Time is local time unless 'Z' or 'z' is appended, in which case it is
172 If the year-month-day part is not specified it takes the current
175 @item -metadata[:metadata_specifier] @var{key}=@var{value} (@emph{output,per-metadata})
176 Set a metadata key/value pair.
178 An optional @var{metadata_specifier} may be given to set metadata
179 on streams or chapters. See @code{-map_metadata} documentation for
182 This option overrides metadata set with @code{-map_metadata}. It is
183 also possible to delete metadata by using an empty value.
185 For example, for setting the title in the output file:
187 ffmpeg -i in.avi -metadata title="my title" out.flv
190 To set the language of the first audio stream:
192 ffmpeg -i INPUT -metadata:s:a:1 language=eng OUTPUT
195 @item -target @var{type} (@emph{output})
196 Specify target file type (@code{vcd}, @code{svcd}, @code{dvd}, @code{dv},
197 @code{dv50}). @var{type} may be prefixed with @code{pal-}, @code{ntsc-} or
198 @code{film-} to use the corresponding standard. All the format options
199 (bitrate, codecs, buffer sizes) are then set automatically. You can just type:
202 ffmpeg -i myfile.avi -target vcd /tmp/vcd.mpg
205 Nevertheless you can specify additional options as long as you know
206 they do not conflict with the standard, as in:
209 ffmpeg -i myfile.avi -target vcd -bf 2 /tmp/vcd.mpg
212 @item -dframes @var{number} (@emph{output})
213 Set the number of data frames to record. This is an alias for @code{-frames:d}.
215 @item -frames[:@var{stream_specifier}] @var{framecount} (@emph{output,per-stream})
216 Stop writing to the stream after @var{framecount} frames.
218 @item -q[:@var{stream_specifier}] @var{q} (@emph{output,per-stream})
219 @itemx -qscale[:@var{stream_specifier}] @var{q} (@emph{output,per-stream})
220 Use fixed quality scale (VBR). The meaning of @var{q} is
223 @item -filter[:@var{stream_specifier}] @var{filter_graph} (@emph{output,per-stream})
224 @var{filter_graph} is a description of the filter graph to apply to
225 the stream. Use @code{-filters} to show all the available filters
226 (including also sources and sinks).
227 @item -pre[:@var{stream_specifier}] @var{preset_name} (@emph{output,per-stream})
228 Specify the preset for matching stream(s).
230 @item -stats (@emph{global})
231 Print encoding progress/statistics. On by default.
233 @item -debug_ts (@emph{global})
234 Print timestamp information. It is off by default. This option is
235 mostly useful for testing and debugging purposes, and the output
236 format may change from one version to another, so it should not be
237 employed by portable scripts.
239 See also the option @code{-fdebug ts}.
241 @item -attach @var{filename} (@emph{output})
242 Add an attachment to the output file. This is supported by a few formats
243 like Matroska for e.g. fonts used in rendering subtitles. Attachments
244 are implemented as a specific type of stream, so this option will add
245 a new stream to the file. It is then possible to use per-stream options
246 on this stream in the usual way. Attachment streams created with this
247 option will be created after all the other streams (i.e. those created
248 with @code{-map} or automatic mappings).
250 Note that for Matroska you also have to set the mimetype metadata tag:
252 ffmpeg -i INPUT -attach DejaVuSans.ttf -metadata:s:2 mimetype=application/x-truetype-font out.mkv
254 (assuming that the attachment stream will be third in the output file).
256 @item -dump_attachment[:@var{stream_specifier}] @var{filename} (@emph{input,per-stream})
257 Extract the matching attachment stream into a file named @var{filename}. If
258 @var{filename} is empty, then the value of the @code{filename} metadata tag
261 E.g. to extract the first attachment to a file named 'out.ttf':
263 ffmpeg -dump_attachment:t:0 out.ttf INPUT
265 To extract all attachments to files determined by the @code{filename} tag:
267 ffmpeg -dump_attachment:t "" INPUT
270 Technical note -- attachments are implemented as codec extradata, so this
271 option can actually be used to extract extradata from any stream, not just
276 @section Video Options
279 @item -vframes @var{number} (@emph{output})
280 Set the number of video frames to record. This is an alias for @code{-frames:v}.
281 @item -r[:@var{stream_specifier}] @var{fps} (@emph{input/output,per-stream})
282 Set frame rate (Hz value, fraction or abbreviation), (default = 25).
283 @item -s[:@var{stream_specifier}] @var{size} (@emph{input/output,per-stream})
284 Set frame size. The format is @samp{wxh} (default - same as source).
285 The following abbreviations are recognized:
347 @item -aspect[:@var{stream_specifier}] @var{aspect} (@emph{output,per-stream})
348 Set the video display aspect ratio specified by @var{aspect}.
350 @var{aspect} can be a floating point number string, or a string of the
351 form @var{num}:@var{den}, where @var{num} and @var{den} are the
352 numerator and denominator of the aspect ratio. For example "4:3",
353 "16:9", "1.3333", and "1.7777" are valid argument values.
355 @item -croptop @var{size}
356 @item -cropbottom @var{size}
357 @item -cropleft @var{size}
358 @item -cropright @var{size}
359 All the crop options have been removed. Use -vf
360 crop=width:height:x:y instead.
362 @item -padtop @var{size}
363 @item -padbottom @var{size}
364 @item -padleft @var{size}
365 @item -padright @var{size}
366 @item -padcolor @var{hex_color}
367 All the pad options have been removed. Use -vf
368 pad=width:height:x:y:color instead.
370 @item -vn (@emph{output})
371 Disable video recording.
372 @item -bt @var{tolerance}
373 Set video bitrate tolerance (in bits, default 4000k).
374 Has a minimum value of: (target_bitrate/target_framerate).
375 In 1-pass mode, bitrate tolerance specifies how far ratecontrol is
376 willing to deviate from the target average bitrate value. This is
377 not related to min/max bitrate. Lowering tolerance too much has
378 an adverse effect on quality.
379 @item -maxrate @var{bitrate}
380 Set max video bitrate (in bit/s).
381 Requires -bufsize to be set.
382 @item -minrate @var{bitrate}
383 Set min video bitrate (in bit/s).
384 Most useful in setting up a CBR encode:
386 ffmpeg -i myfile.avi -b:v 4000k -minrate 4000k -maxrate 4000k -bufsize 1835k out.m2v
388 It is of little use elsewise.
389 @item -bufsize @var{size}
390 Set video buffer verifier buffer size (in bits).
391 @item -vcodec @var{codec} (@emph{output})
392 Set the video codec. This is an alias for @code{-codec:v}.
394 Use same quantizer as source (implies VBR).
396 Note that this is NOT SAME QUALITY. Do not use this option unless you know you
400 Select the pass number (1 or 2). It is used to do two-pass
401 video encoding. The statistics of the video are recorded in the first
402 pass into a log file (see also the option -passlogfile),
403 and in the second pass that log file is used to generate the video
404 at the exact requested bitrate.
405 On pass 1, you may just deactivate audio and set output to null,
406 examples for Windows and Unix:
408 ffmpeg -i foo.mov -c:v libxvid -pass 1 -an -f rawvideo -y NUL
409 ffmpeg -i foo.mov -c:v libxvid -pass 1 -an -f rawvideo -y /dev/null
412 @item -passlogfile @var{prefix} (@emph{global})
413 Set two-pass log file name prefix to @var{prefix}, the default file name
414 prefix is ``ffmpeg2pass''. The complete file name will be
415 @file{PREFIX-N.log}, where N is a number specific to the output
418 @item -vlang @var{code}
419 Set the ISO 639 language code (3 letters) of the current video stream.
421 @item -vf @var{filter_graph} (@emph{output})
422 @var{filter_graph} is a description of the filter graph to apply to
424 Use the option "-filters" to show all the available filters (including
425 also sources and sinks). This is an alias for @code{-filter:v}.
429 @section Advanced Video Options
432 @item -pix_fmt[:@var{stream_specifier}] @var{format} (@emph{input/output,per-stream})
433 Set pixel format. Use @code{-pix_fmts} to show all the supported
435 @item -sws_flags @var{flags} (@emph{input/output})
437 @item -g @var{gop_size}
438 Set the group of pictures size.
444 minimum video quantizer scale (VBR)
446 maximum video quantizer scale (VBR)
448 maximum difference between the quantizer scales (VBR)
449 @item -qblur @var{blur}
450 video quantizer scale blur (VBR) (range 0.0 - 1.0)
451 @item -qcomp @var{compression}
452 video quantizer scale compression (VBR) (default 0.5).
453 Constant of ratecontrol equation. Recommended range for default rc_eq: 0.0-1.0
455 @item -lmin @var{lambda}
456 minimum video lagrange factor (VBR)
457 @item -lmax @var{lambda}
458 max video lagrange factor (VBR)
459 @item -mblmin @var{lambda}
460 minimum macroblock quantizer scale (VBR)
461 @item -mblmax @var{lambda}
462 maximum macroblock quantizer scale (VBR)
464 These four options (lmin, lmax, mblmin, mblmax) use 'lambda' units,
465 but you may use the QP2LAMBDA constant to easily convert from 'q' units:
467 ffmpeg -i src.ext -lmax 21*QP2LAMBDA dst.ext
470 @item -rc_init_cplx @var{complexity}
471 initial complexity for single pass encoding
472 @item -b_qfactor @var{factor}
473 qp factor between P- and B-frames
474 @item -i_qfactor @var{factor}
475 qp factor between P- and I-frames
476 @item -b_qoffset @var{offset}
477 qp offset between P- and B-frames
478 @item -i_qoffset @var{offset}
479 qp offset between P- and I-frames
480 @item -rc_eq @var{equation}
481 Set rate control equation (see section "Expression Evaluation")
482 (default = @code{tex^qComp}).
484 When computing the rate control equation expression, besides the
485 standard functions defined in the section "Expression Evaluation", the
486 following functions are available:
492 and the following constants are available:
514 @item -rc_override[:@var{stream_specifier}] @var{override} (@emph{output,per-stream})
515 Rate control override for specific intervals, formatted as "int,int,int"
516 list separated with slashes. Two first values are the beginning and
517 end frame numbers, last one is quantizer to use if positive, or quality
519 @item -me_method @var{method}
520 Set motion estimation method to @var{method}.
521 Available methods are (from lowest to best quality):
524 Try just the (0, 0) vector.
533 exhaustive search (slow and marginally better than epzs)
536 @item -dct_algo @var{algo}
537 Set DCT algorithm to @var{algo}. Available values are:
540 FF_DCT_AUTO (default)
553 @item -idct_algo @var{algo}
554 Set IDCT algorithm to @var{algo}. Available values are:
557 FF_IDCT_AUTO (default)
581 Set error resilience to @var{n}.
584 FF_ER_CAREFUL (default)
590 FF_ER_VERY_AGGRESSIVE
593 @item -ec @var{bit_mask}
594 Set error concealment to @var{bit_mask}. @var{bit_mask} is a bit mask of
595 the following values:
598 FF_EC_GUESS_MVS (default = enabled)
600 FF_EC_DEBLOCK (default = enabled)
603 @item -bf @var{frames}
604 Use 'frames' B-frames (supported for MPEG-1, MPEG-2 and MPEG-4).
605 @item -mbd @var{mode}
609 FF_MB_DECISION_SIMPLE: Use mb_cmp (cannot change it yet in ffmpeg).
611 FF_MB_DECISION_BITS: Choose the one which needs the fewest bits.
613 FF_MB_DECISION_RD: rate distortion
617 Use four motion vector by macroblock (MPEG-4 only).
619 Use data partitioning (MPEG-4 only).
620 @item -bug @var{param}
621 Work around encoder bugs that are not auto-detected.
622 @item -strict @var{strictness}
623 How strictly to follow the standards.
625 Enable Advanced intra coding (h263+).
627 Enable Unlimited Motion Vector (h263+)
630 Deinterlace pictures.
631 This option is deprecated since the deinterlacing is very low quality.
632 Use the yadif filter with @code{-filter:v yadif}.
634 Force interlacing support in encoder (MPEG-2 and MPEG-4 only).
635 Use this option if your input file is interlaced and you want
636 to keep the interlaced format for minimum losses.
637 The alternative is to deinterlace the input stream with
638 @option{-deinterlace}, but deinterlacing introduces losses.
640 Calculate PSNR of compressed frames.
642 Dump video coding statistics to @file{vstats_HHMMSS.log}.
643 @item -vstats_file @var{file}
644 Dump video coding statistics to @var{file}.
645 @item -top[:@var{stream_specifier}] @var{n} (@emph{output,per-stream})
646 top=1/bottom=0/auto=-1 field first
647 @item -dc @var{precision}
649 @item -vtag @var{fourcc/tag} (@emph{output})
650 Force video tag/fourcc. This is an alias for @code{-tag:v}.
651 @item -qphist (@emph{global})
653 @item -vbsf @var{bitstream_filter}
655 @item -force_key_frames[:@var{stream_specifier}] @var{time}[,@var{time}...] (@emph{output,per-stream})
656 Force key frames at the specified timestamps, more precisely at the first
657 frames after each specified time.
658 This option can be useful to ensure that a seek point is present at a
659 chapter mark or any other designated place in the output file.
660 The timestamps must be specified in ascending order.
662 @item -copyinkf[:@var{stream_specifier}] (@emph{output,per-stream})
663 When doing stream copy, copy also non-key frames found at the
667 @section Audio Options
670 @item -aframes @var{number} (@emph{output})
671 Set the number of audio frames to record. This is an alias for @code{-frames:a}.
672 @item -ar[:@var{stream_specifier}] @var{freq} (@emph{input/output,per-stream})
673 Set the audio sampling frequency. For output streams it is set by
674 default to the frequency of the corresponding input stream. For input
675 streams this option only makes sense for audio grabbing devices and raw
676 demuxers and is mapped to the corresponding demuxer options.
677 @item -aq @var{q} (@emph{output})
678 Set the audio quality (codec-specific, VBR). This is an alias for -q:a.
679 @item -ac[:@var{stream_specifier}] @var{channels} (@emph{input/output,per-stream})
680 Set the number of audio channels. For output streams it is set by
681 default to the number of input audio channels. For input streams
682 this option only makes sense for audio grabbing devices and raw demuxers
683 and is mapped to the corresponding demuxer options.
684 @item -an (@emph{output})
685 Disable audio recording.
686 @item -acodec @var{codec} (@emph{input/output})
687 Set the audio codec. This is an alias for @code{-codec:a}.
688 @item -sample_fmt[:@var{stream_specifier}] @var{sample_fmt} (@emph{output,per-stream})
689 Set the audio sample format. Use @code{-sample_fmts} to get a list
690 of supported sample formats.
693 @section Advanced Audio options:
696 @item -atag @var{fourcc/tag} (@emph{output})
697 Force audio tag/fourcc. This is an alias for @code{-tag:a}.
698 @item -audio_service_type @var{type}
699 Set the type of service that the audio stream contains.
702 Main Audio Service (default)
720 @item -absf @var{bitstream_filter}
724 @section Subtitle options:
727 @item -slang @var{code}
728 Set the ISO 639 language code (3 letters) of the current subtitle stream.
729 @item -scodec @var{codec} (@emph{input/output})
730 Set the subtitle codec. This is an alias for @code{-codec:s}.
731 @item -sn (@emph{output})
732 Disable subtitle recording.
733 @item -sbsf @var{bitstream_filter}
737 @section Audio/Video grab options
740 @item -isync (@emph{global})
741 Synchronize read on input.
744 @section Advanced options
747 @item -map [-]@var{input_file_id}[:@var{stream_specifier}][,@var{sync_file_id}[:@var{stream_specifier}]] (@emph{output})
749 Designate one or more input streams as a source for the output file. Each input
750 stream is identified by the input file index @var{input_file_id} and
751 the input stream index @var{input_stream_id} within the input
752 file. Both indices start at 0. If specified,
753 @var{sync_file_id}:@var{stream_specifier} sets which input stream
754 is used as a presentation sync reference.
756 The first @code{-map} option on the command line specifies the
757 source for output stream 0, the second @code{-map} option specifies
758 the source for output stream 1, etc.
760 A @code{-} character before the stream identifier creates a "negative" mapping.
761 It disables matching streams from already created mappings.
763 For example, to map ALL streams from the first input file to output
765 ffmpeg -i INPUT -map 0 output
768 For example, if you have two audio streams in the first input file,
769 these streams are identified by "0:0" and "0:1". You can use
770 @code{-map} to select which streams to place in an output file. For
773 ffmpeg -i INPUT -map 0:1 out.wav
775 will map the input stream in @file{INPUT} identified by "0:1" to
776 the (single) output stream in @file{out.wav}.
778 For example, to select the stream with index 2 from input file
779 @file{a.mov} (specified by the identifier "0:2"), and stream with
780 index 6 from input @file{b.mov} (specified by the identifier "1:6"),
781 and copy them to the output file @file{out.mov}:
783 ffmpeg -i a.mov -i b.mov -c copy -map 0:2 -map 1:6 out.mov
786 To select all video and the third audio stream from an input file:
788 ffmpeg -i INPUT -map 0:v -map 0:a:2 OUTPUT
791 To map all the streams except the second audio, use negative mappings
793 ffmpeg -i INPUT -map 0 -map -0:a:1 OUTPUT
796 Note that using this option disables the default mappings for this output file.
798 @item -map_channel [@var{input_file_id}.@var{stream_specifier}.@var{channel_id}|-1][:@var{output_file_id}.@var{stream_specifier}]
799 Map an audio channel from a given input to an output. If
800 @var{output_file_id}.@var{stream_specifier} are not set, the audio channel will
801 be mapped on all the audio streams.
803 Using "-1" instead of
804 @var{input_file_id}.@var{stream_specifier}.@var{channel_id} will map a muted
807 For example, assuming @var{INPUT} is a stereo audio file, you can switch the
808 two audio channels with the following command:
810 ffmpeg -i INPUT -map_channel 0.0.1 -map_channel 0.0.0 OUTPUT
813 If you want to mute the first channel and keep the second:
815 ffmpeg -i INPUT -map_channel -1 -map_channel 0.0.1 OUTPUT
818 The order of the "-map_channel" option specifies the order of the channels in
819 the output stream. The output channel layout is guessed from the number of
820 channels mapped (mono if one "-map_channel", stereo if two, etc.). Using "-ac"
821 in combination of "-map_channel" makes the channel gain levels to be updated if
822 channel layouts don't match (for instance two "-map_channel" options and "-ac
825 You can also extract each channel of an @var{INPUT} to specific outputs; the
826 following command extract each channel of the audio stream (file 0, stream 0)
827 to the respective @var{OUTPUT_CH0} and @var{OUTPUT_CH1}:
829 ffmpeg -i INPUT -map_channel 0.0.0 OUTPUT_CH0 -map_channel 0.0.1 OUTPUT_CH1
832 The following example split the channels of a stereo input into streams:
835 ffmpeg -i stereo.wav -map 0:0 -map 0:0 -map_channel 0.0.0:0.0 -map_channel 0.0.1:0.1 -y out.ogg
838 Note that currently each output stream can only contain channels from a single
839 input stream; you can't for example use "-map_channel" to pick multiple input
840 audio channels contained in different streams (from the same or different files)
841 and merge them into a single output stream. It is therefore not currently
842 possible, for example, to turn two separate mono streams into a single stereo
843 stream. However spliting a stereo stream into two single channel mono streams
846 If you need this feature, a possible workaround is to use the @emph{amerge}
847 filter. For example, if you need to merge a media (here @file{input.mkv}) with 2
848 mono audio streams into one single stereo channel audio stream (and keep the
852 ffmpeg -i input.mkv -f lavfi -i "
853 amovie=input.mkv:si=1 [a1];
854 amovie=input.mkv:si=2 [a2];
855 [a1][a2] amerge" -c:a pcm_s16le -c:v copy output.mkv
858 @item -map_metadata[:@var{metadata_spec_out}] @var{infile}[:@var{metadata_spec_in}] (@emph{output,per-metadata})
859 Set metadata information of the next output file from @var{infile}. Note that
860 those are file indices (zero-based), not filenames.
861 Optional @var{metadata_spec_in/out} parameters specify, which metadata to copy.
862 A metadata specifier can have the following forms:
865 global metadata, i.e. metadata that applies to the whole file
867 @item @var{s}[:@var{stream_spec}]
868 per-stream metadata. @var{stream_spec} is a stream specifier as described
869 in the @ref{Stream specifiers} chapter. In an input metadata specifier, the first
870 matching stream is copied from. In an output metadata specifier, all matching
871 streams are copied to.
873 @item @var{c}:@var{chapter_index}
874 per-chapter metadata. @var{chapter_index} is the zero-based chapter index.
876 @item @var{p}:@var{program_index}
877 per-program metadata. @var{program_index} is the zero-based program index.
879 If metadata specifier is omitted, it defaults to global.
881 By default, global metadata is copied from the first input file,
882 per-stream and per-chapter metadata is copied along with streams/chapters. These
883 default mappings are disabled by creating any mapping of the relevant type. A negative
884 file index can be used to create a dummy mapping that just disables automatic copying.
886 For example to copy metadata from the first stream of the input file to global metadata
889 ffmpeg -i in.ogg -map_metadata 0:s:0 out.mp3
892 To do the reverse, i.e. copy global metadata to all audio streams:
894 ffmpeg -i in.mkv -map_metadata:s:a 0:g out.mkv
896 Note that simple @code{0} would work as well in this example, since global
897 metadata is assumed by default.
899 @item -map_chapters @var{input_file_index} (@emph{output})
900 Copy chapters from input file with index @var{input_file_index} to the next
901 output file. If no chapter mapping is specified, then chapters are copied from
902 the first input file with at least one chapter. Use a negative file index to
903 disable any chapter copying.
904 @item -debug @var{category}
905 Print specific debug info.
906 @var{category} is a number or a string containing one of the following values:
910 picture buffer allocations
918 memory management control operations (H.264)
925 per-block quantization parameter (QP)
933 visualize block types
935 visualize quantization parameter (QP), lower QP are tinted greener
937 @item -benchmark (@emph{global})
938 Show benchmarking information at the end of an encode.
939 Shows CPU time used and maximum memory consumption.
940 Maximum memory consumption is not supported on all systems,
941 it will usually display as 0 if not supported.
942 @item -timelimit @var{duration} (@emph{global})
943 Exit after ffmpeg has been running for @var{duration} seconds.
944 @item -dump (@emph{global})
945 Dump each input packet to stderr.
946 @item -hex (@emph{global})
947 When dumping packets, also dump the payload.
949 Set RTP payload size in bytes.
950 @item -re (@emph{input})
951 Read input at native frame rate. Mainly used to simulate a grab device.
953 Loop over the input stream. Currently it works only for image
954 streams. This option is used for automatic FFserver testing.
955 This option is deprecated, use -loop 1.
956 @item -loop_output @var{number_of_times}
957 Repeatedly loop output for formats that support looping such as animated GIF
958 (0 will loop the output infinitely).
959 This option is deprecated, use -loop.
960 @item -threads @var{count}
962 @item -vsync @var{parameter}
964 For compatibility reasons old values can be specified as numbers.
965 Newly added values will have to be specified as strings always.
969 Each frame is passed with its timestamp from the demuxer to the muxer.
971 Frames will be duplicated and dropped to achieve exactly the requested
974 Frames are passed through with their timestamp or dropped so as to
975 prevent 2 frames from having the same timestamp.
977 As passthrough but destroys all timestamps, making the muxer generate
978 fresh timestamps based on frame-rate.
980 Chooses between 1 and 2 depending on muxer capabilities. This is the
984 With -map you can select from which stream the timestamps should be
985 taken. You can leave either video or audio unchanged and sync the
986 remaining stream(s) to the unchanged one.
988 @item -async @var{samples_per_second}
989 Audio sync method. "Stretches/squeezes" the audio stream to match the timestamps,
990 the parameter is the maximum samples per second by which the audio is changed.
991 -async 1 is a special case where only the start of the audio stream is corrected
992 without any later correction.
994 Copy timestamps from input to output.
996 Copy input stream time base from input to output when stream copying.
998 Finish encoding when the shortest input stream ends.
999 @item -dts_delta_threshold
1000 Timestamp discontinuity delta threshold.
1001 @item -muxdelay @var{seconds} (@emph{input})
1002 Set the maximum demux-decode delay.
1003 @item -muxpreload @var{seconds} (@emph{input})
1004 Set the initial demux-decode delay.
1005 @item -streamid @var{output-stream-index}:@var{new-value} (@emph{output})
1006 Assign a new stream-id value to an output stream. This option should be
1007 specified prior to the output filename to which it applies.
1008 For the situation where multiple output files exist, a streamid
1009 may be reassigned to a different value.
1011 For example, to set the stream 0 PID to 33 and the stream 1 PID to 36 for
1012 an output mpegts file:
1014 ffmpeg -i infile -streamid 0:33 -streamid 1:36 out.ts
1017 @item -bsf[:@var{stream_specifier}] @var{bitstream_filters} (@emph{output,per-stream})
1018 Set bitstream filters for matching streams. @var{bistream_filters} is
1019 a comma-separated list of bitstream filters. Use the @code{-bsfs} option
1020 to get the list of bitstream filters.
1022 ffmpeg -i h264.mp4 -c:v copy -vbsf h264_mp4toannexb -an out.h264
1025 ffmpeg -i file.mov -an -vn -sbsf mov2textsub -c:s copy -f rawvideo sub.txt
1028 @item -tag[:@var{stream_specifier}] @var{codec_tag} (@emph{per-stream})
1029 Force a tag/fourcc for matching streams.
1031 @item -timecode @var{hh}:@var{mm}:@var{ss}SEP@var{ff}
1032 Specify Timecode for writing. @var{SEP} is ':' for non drop timecode and ';'
1035 ffmpeg -i input.mpg -timecode 01:02:03.04 -r 30000/1001 -s ntsc output.mpg
1039 @section Preset files
1040 A preset file contains a sequence of @var{option}=@var{value} pairs,
1041 one for each line, specifying a sequence of options which would be
1042 awkward to specify on the command line. Lines starting with the hash
1043 ('#') character are ignored and are used to provide comments. Check
1044 the @file{presets} directory in the FFmpeg source tree for examples.
1046 Preset files are specified with the @code{vpre}, @code{apre},
1047 @code{spre}, and @code{fpre} options. The @code{fpre} option takes the
1048 filename of the preset instead of a preset name as input and can be
1049 used for any kind of codec. For the @code{vpre}, @code{apre}, and
1050 @code{spre} options, the options specified in a preset file are
1051 applied to the currently selected codec of the same type as the preset
1054 The argument passed to the @code{vpre}, @code{apre}, and @code{spre}
1055 preset options identifies the preset file to use according to the
1058 First ffmpeg searches for a file named @var{arg}.ffpreset in the
1059 directories @file{$FFMPEG_DATADIR} (if set), and @file{$HOME/.ffmpeg}, and in
1060 the datadir defined at configuration time (usually @file{PREFIX/share/ffmpeg})
1061 or in a @file{ffpresets} folder along the executable on win32,
1062 in that order. For example, if the argument is @code{libx264-max}, it will
1063 search for the file @file{libx264-max.ffpreset}.
1065 If no such file is found, then ffmpeg will search for a file named
1066 @var{codec_name}-@var{arg}.ffpreset in the above-mentioned
1067 directories, where @var{codec_name} is the name of the codec to which
1068 the preset file options will be applied. For example, if you select
1069 the video codec with @code{-vcodec libx264} and use @code{-vpre max},
1070 then it will search for the file @file{libx264-max.ffpreset}.
1078 For streaming at very low bitrate application, use a low frame rate
1079 and a small GOP size. This is especially true for RealVideo where
1080 the Linux player does not seem to be very fast, so it can miss
1081 frames. An example is:
1084 ffmpeg -g 3 -r 3 -t 10 -b:v 50k -s qcif -f rv10 /tmp/b.rm
1088 The parameter 'q' which is displayed while encoding is the current
1089 quantizer. The value 1 indicates that a very good quality could
1090 be achieved. The value 31 indicates the worst quality. If q=31 appears
1091 too often, it means that the encoder cannot compress enough to meet
1092 your bitrate. You must either increase the bitrate, decrease the
1093 frame rate or decrease the frame size.
1096 If your computer is not fast enough, you can speed up the
1097 compression at the expense of the compression ratio. You can use
1098 '-me zero' to speed up motion estimation, and '-intra' to disable
1099 motion estimation completely (you have only I-frames, which means it
1100 is about as good as JPEG compression).
1103 To have very low audio bitrates, reduce the sampling frequency
1104 (down to 22050 Hz for MPEG audio, 22050 or 11025 for AC-3).
1107 To have a constant quality (but a variable bitrate), use the option
1108 '-qscale n' when 'n' is between 1 (excellent quality) and 31 (worst
1115 @c man begin EXAMPLES
1117 @section Preset files
1119 A preset file contains a sequence of @var{option=value} pairs, one for
1120 each line, specifying a sequence of options which can be specified also on
1121 the command line. Lines starting with the hash ('#') character are ignored and
1122 are used to provide comments. Empty lines are also ignored. Check the
1123 @file{presets} directory in the FFmpeg source tree for examples.
1125 Preset files are specified with the @code{pre} option, this option takes a
1126 preset name as input. FFmpeg searches for a file named @var{preset_name}.avpreset in
1127 the directories @file{$AVCONV_DATADIR} (if set), and @file{$HOME/.ffmpeg}, and in
1128 the data directory defined at configuration time (usually @file{$PREFIX/share/ffmpeg})
1129 in that order. For example, if the argument is @code{libx264-max}, it will
1130 search for the file @file{libx264-max.avpreset}.
1132 @section Video and Audio grabbing
1134 If you specify the input format and device then ffmpeg can grab video
1138 ffmpeg -f oss -i /dev/dsp -f video4linux2 -i /dev/video0 /tmp/out.mpg
1141 Or with an ALSA audio source (mono input, card id 1) instead of OSS:
1143 ffmpeg -f alsa -ac 1 -i hw:1 -f video4linux2 -i /dev/video0 /tmp/out.mpg
1146 Note that you must activate the right video source and channel before
1147 launching ffmpeg with any TV viewer such as
1148 @uref{http://linux.bytesex.org/xawtv/, xawtv} by Gerd Knorr. You also
1149 have to set the audio recording levels correctly with a
1152 @section X11 grabbing
1154 Grab the X11 display with ffmpeg via
1157 ffmpeg -f x11grab -s cif -r 25 -i :0.0 /tmp/out.mpg
1160 0.0 is display.screen number of your X11 server, same as
1161 the DISPLAY environment variable.
1164 ffmpeg -f x11grab -s cif -r 25 -i :0.0+10,20 /tmp/out.mpg
1167 0.0 is display.screen number of your X11 server, same as the DISPLAY environment
1168 variable. 10 is the x-offset and 20 the y-offset for the grabbing.
1170 @section Video and Audio file format conversion
1172 Any supported file format and protocol can serve as input to ffmpeg:
1177 You can use YUV files as input:
1180 ffmpeg -i /tmp/test%d.Y /tmp/out.mpg
1183 It will use the files:
1185 /tmp/test0.Y, /tmp/test0.U, /tmp/test0.V,
1186 /tmp/test1.Y, /tmp/test1.U, /tmp/test1.V, etc...
1189 The Y files use twice the resolution of the U and V files. They are
1190 raw files, without header. They can be generated by all decent video
1191 decoders. You must specify the size of the image with the @option{-s} option
1192 if ffmpeg cannot guess it.
1195 You can input from a raw YUV420P file:
1198 ffmpeg -i /tmp/test.yuv /tmp/out.avi
1201 test.yuv is a file containing raw YUV planar data. Each frame is composed
1202 of the Y plane followed by the U and V planes at half vertical and
1203 horizontal resolution.
1206 You can output to a raw YUV420P file:
1209 ffmpeg -i mydivx.avi hugefile.yuv
1213 You can set several input files and output files:
1216 ffmpeg -i /tmp/a.wav -s 640x480 -i /tmp/a.yuv /tmp/a.mpg
1219 Converts the audio file a.wav and the raw YUV video file a.yuv
1223 You can also do audio and video conversions at the same time:
1226 ffmpeg -i /tmp/a.wav -ar 22050 /tmp/a.mp2
1229 Converts a.wav to MPEG audio at 22050 Hz sample rate.
1232 You can encode to several formats at the same time and define a
1233 mapping from input stream to output streams:
1236 ffmpeg -i /tmp/a.wav -map 0:a -b:a 64k /tmp/a.mp2 -map 0:a -b:a 128k /tmp/b.mp2
1239 Converts a.wav to a.mp2 at 64 kbits and to b.mp2 at 128 kbits. '-map
1240 file:index' specifies which input stream is used for each output
1241 stream, in the order of the definition of output streams.
1244 You can transcode decrypted VOBs:
1247 ffmpeg -i snatch_1.vob -f avi -c:v mpeg4 -b:v 800k -g 300 -bf 2 -c:a libmp3lame -b:a 128k snatch.avi
1250 This is a typical DVD ripping example; the input is a VOB file, the
1251 output an AVI file with MPEG-4 video and MP3 audio. Note that in this
1252 command we use B-frames so the MPEG-4 stream is DivX5 compatible, and
1253 GOP size is 300 which means one intra frame every 10 seconds for 29.97fps
1254 input video. Furthermore, the audio stream is MP3-encoded so you need
1255 to enable LAME support by passing @code{--enable-libmp3lame} to configure.
1256 The mapping is particularly useful for DVD transcoding
1257 to get the desired audio language.
1259 NOTE: To see the supported input formats, use @code{ffmpeg -formats}.
1262 You can extract images from a video, or create a video from many images:
1264 For extracting images from a video:
1266 ffmpeg -i foo.avi -r 1 -s WxH -f image2 foo-%03d.jpeg
1269 This will extract one video frame per second from the video and will
1270 output them in files named @file{foo-001.jpeg}, @file{foo-002.jpeg},
1271 etc. Images will be rescaled to fit the new WxH values.
1273 If you want to extract just a limited number of frames, you can use the
1274 above command in combination with the -vframes or -t option, or in
1275 combination with -ss to start extracting from a certain point in time.
1277 For creating a video from many images:
1279 ffmpeg -f image2 -i foo-%03d.jpeg -r 12 -s WxH foo.avi
1282 The syntax @code{foo-%03d.jpeg} specifies to use a decimal number
1283 composed of three digits padded with zeroes to express the sequence
1284 number. It is the same syntax supported by the C printf function, but
1285 only formats accepting a normal integer are suitable.
1288 You can put many streams of the same type in the output:
1291 ffmpeg -i test1.avi -i test2.avi -map 0.3 -map 0.2 -map 0.1 -map 0.0 -c copy test12.nut
1294 The resulting output file @file{test12.avi} will contain first four streams from
1295 the input file in reverse order.
1301 @include decoders.texi
1302 @include encoders.texi
1303 @include demuxers.texi
1304 @include muxers.texi
1305 @include indevs.texi
1306 @include outdevs.texi
1307 @include protocols.texi
1308 @include bitstream_filters.texi
1309 @include filters.texi
1310 @include metadata.texi
1315 @settitle ffmpeg video converter
1317 @c man begin SEEALSO
1318 ffplay(1), ffprobe(1), ffserver(1) and the FFmpeg HTML documentation
1321 @c man begin AUTHORS