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). For output
283 streams implies @code{-vsync cfr}.
284 @item -s[:@var{stream_specifier}] @var{size} (@emph{input/output,per-stream})
285 Set frame size. The format is @samp{wxh} (default - same as source).
286 The following abbreviations are recognized:
348 @item -aspect[:@var{stream_specifier}] @var{aspect} (@emph{output,per-stream})
349 Set the video display aspect ratio specified by @var{aspect}.
351 @var{aspect} can be a floating point number string, or a string of the
352 form @var{num}:@var{den}, where @var{num} and @var{den} are the
353 numerator and denominator of the aspect ratio. For example "4:3",
354 "16:9", "1.3333", and "1.7777" are valid argument values.
356 @item -croptop @var{size}
357 @item -cropbottom @var{size}
358 @item -cropleft @var{size}
359 @item -cropright @var{size}
360 All the crop options have been removed. Use -vf
361 crop=width:height:x:y instead.
363 @item -padtop @var{size}
364 @item -padbottom @var{size}
365 @item -padleft @var{size}
366 @item -padright @var{size}
367 @item -padcolor @var{hex_color}
368 All the pad options have been removed. Use -vf
369 pad=width:height:x:y:color instead.
371 @item -vn (@emph{output})
372 Disable video recording.
373 @item -bt @var{tolerance}
374 Set video bitrate tolerance (in bits, default 4000k).
375 Has a minimum value of: (target_bitrate/target_framerate).
376 In 1-pass mode, bitrate tolerance specifies how far ratecontrol is
377 willing to deviate from the target average bitrate value. This is
378 not related to min/max bitrate. Lowering tolerance too much has
379 an adverse effect on quality.
380 @item -maxrate @var{bitrate}
381 Set max video bitrate (in bit/s).
382 Requires -bufsize to be set.
383 @item -minrate @var{bitrate}
384 Set min video bitrate (in bit/s).
385 Most useful in setting up a CBR encode:
387 ffmpeg -i myfile.avi -b:v 4000k -minrate 4000k -maxrate 4000k -bufsize 1835k out.m2v
389 It is of little use elsewise.
390 @item -bufsize @var{size}
391 Set video buffer verifier buffer size (in bits).
392 @item -vcodec @var{codec} (@emph{output})
393 Set the video codec. This is an alias for @code{-codec:v}.
395 Use same quantizer as source (implies VBR).
397 Note that this is NOT SAME QUALITY. Do not use this option unless you know you
401 Select the pass number (1 or 2). It is used to do two-pass
402 video encoding. The statistics of the video are recorded in the first
403 pass into a log file (see also the option -passlogfile),
404 and in the second pass that log file is used to generate the video
405 at the exact requested bitrate.
406 On pass 1, you may just deactivate audio and set output to null,
407 examples for Windows and Unix:
409 ffmpeg -i foo.mov -c:v libxvid -pass 1 -an -f rawvideo -y NUL
410 ffmpeg -i foo.mov -c:v libxvid -pass 1 -an -f rawvideo -y /dev/null
413 @item -passlogfile @var{prefix} (@emph{global})
414 Set two-pass log file name prefix to @var{prefix}, the default file name
415 prefix is ``ffmpeg2pass''. The complete file name will be
416 @file{PREFIX-N.log}, where N is a number specific to the output
419 @item -vlang @var{code}
420 Set the ISO 639 language code (3 letters) of the current video stream.
422 @item -vf @var{filter_graph} (@emph{output})
423 @var{filter_graph} is a description of the filter graph to apply to
425 Use the option "-filters" to show all the available filters (including
426 also sources and sinks). This is an alias for @code{-filter:v}.
430 @section Advanced Video Options
433 @item -pix_fmt[:@var{stream_specifier}] @var{format} (@emph{input/output,per-stream})
434 Set pixel format. Use @code{-pix_fmts} to show all the supported
436 @item -sws_flags @var{flags} (@emph{input/output})
438 @item -g @var{gop_size}
439 Set the group of pictures size.
445 minimum video quantizer scale (VBR)
447 maximum video quantizer scale (VBR)
449 maximum difference between the quantizer scales (VBR)
450 @item -qblur @var{blur}
451 video quantizer scale blur (VBR) (range 0.0 - 1.0)
452 @item -qcomp @var{compression}
453 video quantizer scale compression (VBR) (default 0.5).
454 Constant of ratecontrol equation. Recommended range for default rc_eq: 0.0-1.0
456 @item -lmin @var{lambda}
457 minimum video lagrange factor (VBR)
458 @item -lmax @var{lambda}
459 max video lagrange factor (VBR)
460 @item -mblmin @var{lambda}
461 minimum macroblock quantizer scale (VBR)
462 @item -mblmax @var{lambda}
463 maximum macroblock quantizer scale (VBR)
465 These four options (lmin, lmax, mblmin, mblmax) use 'lambda' units,
466 but you may use the QP2LAMBDA constant to easily convert from 'q' units:
468 ffmpeg -i src.ext -lmax 21*QP2LAMBDA dst.ext
471 @item -rc_init_cplx @var{complexity}
472 initial complexity for single pass encoding
473 @item -b_qfactor @var{factor}
474 qp factor between P- and B-frames
475 @item -i_qfactor @var{factor}
476 qp factor between P- and I-frames
477 @item -b_qoffset @var{offset}
478 qp offset between P- and B-frames
479 @item -i_qoffset @var{offset}
480 qp offset between P- and I-frames
481 @item -rc_eq @var{equation}
482 Set rate control equation (see section "Expression Evaluation")
483 (default = @code{tex^qComp}).
485 When computing the rate control equation expression, besides the
486 standard functions defined in the section "Expression Evaluation", the
487 following functions are available:
493 and the following constants are available:
515 @item -rc_override[:@var{stream_specifier}] @var{override} (@emph{output,per-stream})
516 Rate control override for specific intervals, formatted as "int,int,int"
517 list separated with slashes. Two first values are the beginning and
518 end frame numbers, last one is quantizer to use if positive, or quality
520 @item -me_method @var{method}
521 Set motion estimation method to @var{method}.
522 Available methods are (from lowest to best quality):
525 Try just the (0, 0) vector.
534 exhaustive search (slow and marginally better than epzs)
537 @item -dct_algo @var{algo}
538 Set DCT algorithm to @var{algo}. Available values are:
541 FF_DCT_AUTO (default)
554 @item -idct_algo @var{algo}
555 Set IDCT algorithm to @var{algo}. Available values are:
558 FF_IDCT_AUTO (default)
582 Set error resilience to @var{n}.
585 FF_ER_CAREFUL (default)
591 FF_ER_VERY_AGGRESSIVE
594 @item -ec @var{bit_mask}
595 Set error concealment to @var{bit_mask}. @var{bit_mask} is a bit mask of
596 the following values:
599 FF_EC_GUESS_MVS (default = enabled)
601 FF_EC_DEBLOCK (default = enabled)
604 @item -bf @var{frames}
605 Use 'frames' B-frames (supported for MPEG-1, MPEG-2 and MPEG-4).
606 @item -mbd @var{mode}
610 FF_MB_DECISION_SIMPLE: Use mb_cmp (cannot change it yet in ffmpeg).
612 FF_MB_DECISION_BITS: Choose the one which needs the fewest bits.
614 FF_MB_DECISION_RD: rate distortion
618 Use four motion vector by macroblock (MPEG-4 only).
620 Use data partitioning (MPEG-4 only).
621 @item -bug @var{param}
622 Work around encoder bugs that are not auto-detected.
623 @item -strict @var{strictness}
624 How strictly to follow the standards.
626 Enable Advanced intra coding (h263+).
628 Enable Unlimited Motion Vector (h263+)
631 Deinterlace pictures.
632 This option is deprecated since the deinterlacing is very low quality.
633 Use the yadif filter with @code{-filter:v yadif}.
635 Force interlacing support in encoder (MPEG-2 and MPEG-4 only).
636 Use this option if your input file is interlaced and you want
637 to keep the interlaced format for minimum losses.
638 The alternative is to deinterlace the input stream with
639 @option{-deinterlace}, but deinterlacing introduces losses.
641 Calculate PSNR of compressed frames.
643 Dump video coding statistics to @file{vstats_HHMMSS.log}.
644 @item -vstats_file @var{file}
645 Dump video coding statistics to @var{file}.
646 @item -top[:@var{stream_specifier}] @var{n} (@emph{output,per-stream})
647 top=1/bottom=0/auto=-1 field first
648 @item -dc @var{precision}
650 @item -vtag @var{fourcc/tag} (@emph{output})
651 Force video tag/fourcc. This is an alias for @code{-tag:v}.
652 @item -qphist (@emph{global})
654 @item -vbsf @var{bitstream_filter}
656 @item -force_key_frames[:@var{stream_specifier}] @var{time}[,@var{time}...] (@emph{output,per-stream})
657 Force key frames at the specified timestamps, more precisely at the first
658 frames after each specified time.
659 This option can be useful to ensure that a seek point is present at a
660 chapter mark or any other designated place in the output file.
661 The timestamps must be specified in ascending order.
663 @item -copyinkf[:@var{stream_specifier}] (@emph{output,per-stream})
664 When doing stream copy, copy also non-key frames found at the
668 @section Audio Options
671 @item -aframes @var{number} (@emph{output})
672 Set the number of audio frames to record. This is an alias for @code{-frames:a}.
673 @item -ar[:@var{stream_specifier}] @var{freq} (@emph{input/output,per-stream})
674 Set the audio sampling frequency. For output streams it is set by
675 default to the frequency of the corresponding input stream. For input
676 streams this option only makes sense for audio grabbing devices and raw
677 demuxers and is mapped to the corresponding demuxer options.
678 @item -aq @var{q} (@emph{output})
679 Set the audio quality (codec-specific, VBR). This is an alias for -q:a.
680 @item -ac[:@var{stream_specifier}] @var{channels} (@emph{input/output,per-stream})
681 Set the number of audio channels. For output streams it is set by
682 default to the number of input audio channels. For input streams
683 this option only makes sense for audio grabbing devices and raw demuxers
684 and is mapped to the corresponding demuxer options.
685 @item -an (@emph{output})
686 Disable audio recording.
687 @item -acodec @var{codec} (@emph{input/output})
688 Set the audio codec. This is an alias for @code{-codec:a}.
689 @item -sample_fmt[:@var{stream_specifier}] @var{sample_fmt} (@emph{output,per-stream})
690 Set the audio sample format. Use @code{-sample_fmts} to get a list
691 of supported sample formats.
694 @section Advanced Audio options:
697 @item -atag @var{fourcc/tag} (@emph{output})
698 Force audio tag/fourcc. This is an alias for @code{-tag:a}.
699 @item -audio_service_type @var{type}
700 Set the type of service that the audio stream contains.
703 Main Audio Service (default)
721 @item -absf @var{bitstream_filter}
725 @section Subtitle options:
728 @item -slang @var{code}
729 Set the ISO 639 language code (3 letters) of the current subtitle stream.
730 @item -scodec @var{codec} (@emph{input/output})
731 Set the subtitle codec. This is an alias for @code{-codec:s}.
732 @item -sn (@emph{output})
733 Disable subtitle recording.
734 @item -sbsf @var{bitstream_filter}
738 @section Audio/Video grab options
741 @item -isync (@emph{global})
742 Synchronize read on input.
745 @section Advanced options
748 @item -map [-]@var{input_file_id}[:@var{stream_specifier}][,@var{sync_file_id}[:@var{stream_specifier}]] (@emph{output})
750 Designate one or more input streams as a source for the output file. Each input
751 stream is identified by the input file index @var{input_file_id} and
752 the input stream index @var{input_stream_id} within the input
753 file. Both indices start at 0. If specified,
754 @var{sync_file_id}:@var{stream_specifier} sets which input stream
755 is used as a presentation sync reference.
757 The first @code{-map} option on the command line specifies the
758 source for output stream 0, the second @code{-map} option specifies
759 the source for output stream 1, etc.
761 A @code{-} character before the stream identifier creates a "negative" mapping.
762 It disables matching streams from already created mappings.
764 For example, to map ALL streams from the first input file to output
766 ffmpeg -i INPUT -map 0 output
769 For example, if you have two audio streams in the first input file,
770 these streams are identified by "0:0" and "0:1". You can use
771 @code{-map} to select which streams to place in an output file. For
774 ffmpeg -i INPUT -map 0:1 out.wav
776 will map the input stream in @file{INPUT} identified by "0:1" to
777 the (single) output stream in @file{out.wav}.
779 For example, to select the stream with index 2 from input file
780 @file{a.mov} (specified by the identifier "0:2"), and stream with
781 index 6 from input @file{b.mov} (specified by the identifier "1:6"),
782 and copy them to the output file @file{out.mov}:
784 ffmpeg -i a.mov -i b.mov -c copy -map 0:2 -map 1:6 out.mov
787 To select all video and the third audio stream from an input file:
789 ffmpeg -i INPUT -map 0:v -map 0:a:2 OUTPUT
792 To map all the streams except the second audio, use negative mappings
794 ffmpeg -i INPUT -map 0 -map -0:a:1 OUTPUT
797 Note that using this option disables the default mappings for this output file.
799 @item -map_channel [@var{input_file_id}.@var{stream_specifier}.@var{channel_id}|-1][:@var{output_file_id}.@var{stream_specifier}]
800 Map an audio channel from a given input to an output. If
801 @var{output_file_id}.@var{stream_specifier} are not set, the audio channel will
802 be mapped on all the audio streams.
804 Using "-1" instead of
805 @var{input_file_id}.@var{stream_specifier}.@var{channel_id} will map a muted
808 For example, assuming @var{INPUT} is a stereo audio file, you can switch the
809 two audio channels with the following command:
811 ffmpeg -i INPUT -map_channel 0.0.1 -map_channel 0.0.0 OUTPUT
814 If you want to mute the first channel and keep the second:
816 ffmpeg -i INPUT -map_channel -1 -map_channel 0.0.1 OUTPUT
819 The order of the "-map_channel" option specifies the order of the channels in
820 the output stream. The output channel layout is guessed from the number of
821 channels mapped (mono if one "-map_channel", stereo if two, etc.). Using "-ac"
822 in combination of "-map_channel" makes the channel gain levels to be updated if
823 channel layouts don't match (for instance two "-map_channel" options and "-ac
826 You can also extract each channel of an @var{INPUT} to specific outputs; the
827 following command extract each channel of the audio stream (file 0, stream 0)
828 to the respective @var{OUTPUT_CH0} and @var{OUTPUT_CH1}:
830 ffmpeg -i INPUT -map_channel 0.0.0 OUTPUT_CH0 -map_channel 0.0.1 OUTPUT_CH1
833 The following example split the channels of a stereo input into streams:
836 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
839 Note that currently each output stream can only contain channels from a single
840 input stream; you can't for example use "-map_channel" to pick multiple input
841 audio channels contained in different streams (from the same or different files)
842 and merge them into a single output stream. It is therefore not currently
843 possible, for example, to turn two separate mono streams into a single stereo
844 stream. However spliting a stereo stream into two single channel mono streams
847 If you need this feature, a possible workaround is to use the @emph{amerge}
848 filter. For example, if you need to merge a media (here @file{input.mkv}) with 2
849 mono audio streams into one single stereo channel audio stream (and keep the
853 ffmpeg -i input.mkv -f lavfi -i "
854 amovie=input.mkv:si=1 [a1];
855 amovie=input.mkv:si=2 [a2];
856 [a1][a2] amerge" -c:a pcm_s16le -c:v copy output.mkv
859 @item -map_metadata[:@var{metadata_spec_out}] @var{infile}[:@var{metadata_spec_in}] (@emph{output,per-metadata})
860 Set metadata information of the next output file from @var{infile}. Note that
861 those are file indices (zero-based), not filenames.
862 Optional @var{metadata_spec_in/out} parameters specify, which metadata to copy.
863 A metadata specifier can have the following forms:
866 global metadata, i.e. metadata that applies to the whole file
868 @item @var{s}[:@var{stream_spec}]
869 per-stream metadata. @var{stream_spec} is a stream specifier as described
870 in the @ref{Stream specifiers} chapter. In an input metadata specifier, the first
871 matching stream is copied from. In an output metadata specifier, all matching
872 streams are copied to.
874 @item @var{c}:@var{chapter_index}
875 per-chapter metadata. @var{chapter_index} is the zero-based chapter index.
877 @item @var{p}:@var{program_index}
878 per-program metadata. @var{program_index} is the zero-based program index.
880 If metadata specifier is omitted, it defaults to global.
882 By default, global metadata is copied from the first input file,
883 per-stream and per-chapter metadata is copied along with streams/chapters. These
884 default mappings are disabled by creating any mapping of the relevant type. A negative
885 file index can be used to create a dummy mapping that just disables automatic copying.
887 For example to copy metadata from the first stream of the input file to global metadata
890 ffmpeg -i in.ogg -map_metadata 0:s:0 out.mp3
893 To do the reverse, i.e. copy global metadata to all audio streams:
895 ffmpeg -i in.mkv -map_metadata:s:a 0:g out.mkv
897 Note that simple @code{0} would work as well in this example, since global
898 metadata is assumed by default.
900 @item -map_chapters @var{input_file_index} (@emph{output})
901 Copy chapters from input file with index @var{input_file_index} to the next
902 output file. If no chapter mapping is specified, then chapters are copied from
903 the first input file with at least one chapter. Use a negative file index to
904 disable any chapter copying.
905 @item -debug @var{category}
906 Print specific debug info.
907 @var{category} is a number or a string containing one of the following values:
911 picture buffer allocations
919 memory management control operations (H.264)
926 per-block quantization parameter (QP)
934 visualize block types
936 visualize quantization parameter (QP), lower QP are tinted greener
938 @item -benchmark (@emph{global})
939 Show benchmarking information at the end of an encode.
940 Shows CPU time used and maximum memory consumption.
941 Maximum memory consumption is not supported on all systems,
942 it will usually display as 0 if not supported.
943 @item -timelimit @var{duration} (@emph{global})
944 Exit after ffmpeg has been running for @var{duration} seconds.
945 @item -dump (@emph{global})
946 Dump each input packet to stderr.
947 @item -hex (@emph{global})
948 When dumping packets, also dump the payload.
950 Set RTP payload size in bytes.
951 @item -re (@emph{input})
952 Read input at native frame rate. Mainly used to simulate a grab device.
954 Loop over the input stream. Currently it works only for image
955 streams. This option is used for automatic FFserver testing.
956 This option is deprecated, use -loop 1.
957 @item -loop_output @var{number_of_times}
958 Repeatedly loop output for formats that support looping such as animated GIF
959 (0 will loop the output infinitely).
960 This option is deprecated, use -loop.
961 @item -threads @var{count}
963 @item -vsync @var{parameter}
965 For compatibility reasons old values can be specified as numbers.
966 Newly added values will have to be specified as strings always.
970 Each frame is passed with its timestamp from the demuxer to the muxer.
972 Frames will be duplicated and dropped to achieve exactly the requested
975 Frames are passed through with their timestamp or dropped so as to
976 prevent 2 frames from having the same timestamp.
978 As passthrough but destroys all timestamps, making the muxer generate
979 fresh timestamps based on frame-rate.
981 Chooses between 1 and 2 depending on muxer capabilities. This is the
985 With -map you can select from which stream the timestamps should be
986 taken. You can leave either video or audio unchanged and sync the
987 remaining stream(s) to the unchanged one.
989 @item -async @var{samples_per_second}
990 Audio sync method. "Stretches/squeezes" the audio stream to match the timestamps,
991 the parameter is the maximum samples per second by which the audio is changed.
992 -async 1 is a special case where only the start of the audio stream is corrected
993 without any later correction.
995 Copy timestamps from input to output.
997 Copy input stream time base from input to output when stream copying.
999 Finish encoding when the shortest input stream ends.
1000 @item -dts_delta_threshold
1001 Timestamp discontinuity delta threshold.
1002 @item -muxdelay @var{seconds} (@emph{input})
1003 Set the maximum demux-decode delay.
1004 @item -muxpreload @var{seconds} (@emph{input})
1005 Set the initial demux-decode delay.
1006 @item -streamid @var{output-stream-index}:@var{new-value} (@emph{output})
1007 Assign a new stream-id value to an output stream. This option should be
1008 specified prior to the output filename to which it applies.
1009 For the situation where multiple output files exist, a streamid
1010 may be reassigned to a different value.
1012 For example, to set the stream 0 PID to 33 and the stream 1 PID to 36 for
1013 an output mpegts file:
1015 ffmpeg -i infile -streamid 0:33 -streamid 1:36 out.ts
1018 @item -bsf[:@var{stream_specifier}] @var{bitstream_filters} (@emph{output,per-stream})
1019 Set bitstream filters for matching streams. @var{bistream_filters} is
1020 a comma-separated list of bitstream filters. Use the @code{-bsfs} option
1021 to get the list of bitstream filters.
1023 ffmpeg -i h264.mp4 -c:v copy -bsf:v h264_mp4toannexb -an out.h264
1026 ffmpeg -i file.mov -an -vn -bsf:s mov2textsub -c:s copy -f rawvideo sub.txt
1029 @item -tag[:@var{stream_specifier}] @var{codec_tag} (@emph{per-stream})
1030 Force a tag/fourcc for matching streams.
1032 @item -timecode @var{hh}:@var{mm}:@var{ss}SEP@var{ff}
1033 Specify Timecode for writing. @var{SEP} is ':' for non drop timecode and ';'
1036 ffmpeg -i input.mpg -timecode 01:02:03.04 -r 30000/1001 -s ntsc output.mpg
1040 @section Preset files
1041 A preset file contains a sequence of @var{option}=@var{value} pairs,
1042 one for each line, specifying a sequence of options which would be
1043 awkward to specify on the command line. Lines starting with the hash
1044 ('#') character are ignored and are used to provide comments. Check
1045 the @file{presets} directory in the FFmpeg source tree for examples.
1047 Preset files are specified with the @code{vpre}, @code{apre},
1048 @code{spre}, and @code{fpre} options. The @code{fpre} option takes the
1049 filename of the preset instead of a preset name as input and can be
1050 used for any kind of codec. For the @code{vpre}, @code{apre}, and
1051 @code{spre} options, the options specified in a preset file are
1052 applied to the currently selected codec of the same type as the preset
1055 The argument passed to the @code{vpre}, @code{apre}, and @code{spre}
1056 preset options identifies the preset file to use according to the
1059 First ffmpeg searches for a file named @var{arg}.ffpreset in the
1060 directories @file{$FFMPEG_DATADIR} (if set), and @file{$HOME/.ffmpeg}, and in
1061 the datadir defined at configuration time (usually @file{PREFIX/share/ffmpeg})
1062 or in a @file{ffpresets} folder along the executable on win32,
1063 in that order. For example, if the argument is @code{libx264-max}, it will
1064 search for the file @file{libx264-max.ffpreset}.
1066 If no such file is found, then ffmpeg will search for a file named
1067 @var{codec_name}-@var{arg}.ffpreset in the above-mentioned
1068 directories, where @var{codec_name} is the name of the codec to which
1069 the preset file options will be applied. For example, if you select
1070 the video codec with @code{-vcodec libx264} and use @code{-vpre max},
1071 then it will search for the file @file{libx264-max.ffpreset}.
1079 For streaming at very low bitrate application, use a low frame rate
1080 and a small GOP size. This is especially true for RealVideo where
1081 the Linux player does not seem to be very fast, so it can miss
1082 frames. An example is:
1085 ffmpeg -g 3 -r 3 -t 10 -b:v 50k -s qcif -f rv10 /tmp/b.rm
1089 The parameter 'q' which is displayed while encoding is the current
1090 quantizer. The value 1 indicates that a very good quality could
1091 be achieved. The value 31 indicates the worst quality. If q=31 appears
1092 too often, it means that the encoder cannot compress enough to meet
1093 your bitrate. You must either increase the bitrate, decrease the
1094 frame rate or decrease the frame size.
1097 If your computer is not fast enough, you can speed up the
1098 compression at the expense of the compression ratio. You can use
1099 '-me zero' to speed up motion estimation, and '-intra' to disable
1100 motion estimation completely (you have only I-frames, which means it
1101 is about as good as JPEG compression).
1104 To have very low audio bitrates, reduce the sampling frequency
1105 (down to 22050 Hz for MPEG audio, 22050 or 11025 for AC-3).
1108 To have a constant quality (but a variable bitrate), use the option
1109 '-qscale n' when 'n' is between 1 (excellent quality) and 31 (worst
1116 @c man begin EXAMPLES
1118 @section Preset files
1120 A preset file contains a sequence of @var{option=value} pairs, one for
1121 each line, specifying a sequence of options which can be specified also on
1122 the command line. Lines starting with the hash ('#') character are ignored and
1123 are used to provide comments. Empty lines are also ignored. Check the
1124 @file{presets} directory in the FFmpeg source tree for examples.
1126 Preset files are specified with the @code{pre} option, this option takes a
1127 preset name as input. FFmpeg searches for a file named @var{preset_name}.avpreset in
1128 the directories @file{$AVCONV_DATADIR} (if set), and @file{$HOME/.ffmpeg}, and in
1129 the data directory defined at configuration time (usually @file{$PREFIX/share/ffmpeg})
1130 in that order. For example, if the argument is @code{libx264-max}, it will
1131 search for the file @file{libx264-max.avpreset}.
1133 @section Video and Audio grabbing
1135 If you specify the input format and device then ffmpeg can grab video
1139 ffmpeg -f oss -i /dev/dsp -f video4linux2 -i /dev/video0 /tmp/out.mpg
1142 Or with an ALSA audio source (mono input, card id 1) instead of OSS:
1144 ffmpeg -f alsa -ac 1 -i hw:1 -f video4linux2 -i /dev/video0 /tmp/out.mpg
1147 Note that you must activate the right video source and channel before
1148 launching ffmpeg with any TV viewer such as
1149 @uref{http://linux.bytesex.org/xawtv/, xawtv} by Gerd Knorr. You also
1150 have to set the audio recording levels correctly with a
1153 @section X11 grabbing
1155 Grab the X11 display with ffmpeg via
1158 ffmpeg -f x11grab -s cif -r 25 -i :0.0 /tmp/out.mpg
1161 0.0 is display.screen number of your X11 server, same as
1162 the DISPLAY environment variable.
1165 ffmpeg -f x11grab -s cif -r 25 -i :0.0+10,20 /tmp/out.mpg
1168 0.0 is display.screen number of your X11 server, same as the DISPLAY environment
1169 variable. 10 is the x-offset and 20 the y-offset for the grabbing.
1171 @section Video and Audio file format conversion
1173 Any supported file format and protocol can serve as input to ffmpeg:
1178 You can use YUV files as input:
1181 ffmpeg -i /tmp/test%d.Y /tmp/out.mpg
1184 It will use the files:
1186 /tmp/test0.Y, /tmp/test0.U, /tmp/test0.V,
1187 /tmp/test1.Y, /tmp/test1.U, /tmp/test1.V, etc...
1190 The Y files use twice the resolution of the U and V files. They are
1191 raw files, without header. They can be generated by all decent video
1192 decoders. You must specify the size of the image with the @option{-s} option
1193 if ffmpeg cannot guess it.
1196 You can input from a raw YUV420P file:
1199 ffmpeg -i /tmp/test.yuv /tmp/out.avi
1202 test.yuv is a file containing raw YUV planar data. Each frame is composed
1203 of the Y plane followed by the U and V planes at half vertical and
1204 horizontal resolution.
1207 You can output to a raw YUV420P file:
1210 ffmpeg -i mydivx.avi hugefile.yuv
1214 You can set several input files and output files:
1217 ffmpeg -i /tmp/a.wav -s 640x480 -i /tmp/a.yuv /tmp/a.mpg
1220 Converts the audio file a.wav and the raw YUV video file a.yuv
1224 You can also do audio and video conversions at the same time:
1227 ffmpeg -i /tmp/a.wav -ar 22050 /tmp/a.mp2
1230 Converts a.wav to MPEG audio at 22050 Hz sample rate.
1233 You can encode to several formats at the same time and define a
1234 mapping from input stream to output streams:
1237 ffmpeg -i /tmp/a.wav -map 0:a -b:a 64k /tmp/a.mp2 -map 0:a -b:a 128k /tmp/b.mp2
1240 Converts a.wav to a.mp2 at 64 kbits and to b.mp2 at 128 kbits. '-map
1241 file:index' specifies which input stream is used for each output
1242 stream, in the order of the definition of output streams.
1245 You can transcode decrypted VOBs:
1248 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
1251 This is a typical DVD ripping example; the input is a VOB file, the
1252 output an AVI file with MPEG-4 video and MP3 audio. Note that in this
1253 command we use B-frames so the MPEG-4 stream is DivX5 compatible, and
1254 GOP size is 300 which means one intra frame every 10 seconds for 29.97fps
1255 input video. Furthermore, the audio stream is MP3-encoded so you need
1256 to enable LAME support by passing @code{--enable-libmp3lame} to configure.
1257 The mapping is particularly useful for DVD transcoding
1258 to get the desired audio language.
1260 NOTE: To see the supported input formats, use @code{ffmpeg -formats}.
1263 You can extract images from a video, or create a video from many images:
1265 For extracting images from a video:
1267 ffmpeg -i foo.avi -r 1 -s WxH -f image2 foo-%03d.jpeg
1270 This will extract one video frame per second from the video and will
1271 output them in files named @file{foo-001.jpeg}, @file{foo-002.jpeg},
1272 etc. Images will be rescaled to fit the new WxH values.
1274 If you want to extract just a limited number of frames, you can use the
1275 above command in combination with the -vframes or -t option, or in
1276 combination with -ss to start extracting from a certain point in time.
1278 For creating a video from many images:
1280 ffmpeg -f image2 -i foo-%03d.jpeg -r 12 -s WxH foo.avi
1283 The syntax @code{foo-%03d.jpeg} specifies to use a decimal number
1284 composed of three digits padded with zeroes to express the sequence
1285 number. It is the same syntax supported by the C printf function, but
1286 only formats accepting a normal integer are suitable.
1289 You can put many streams of the same type in the output:
1292 ffmpeg -i test1.avi -i test2.avi -map 0.3 -map 0.2 -map 0.1 -map 0.0 -c copy test12.nut
1295 The resulting output file @file{test12.avi} will contain first four streams from
1296 the input file in reverse order.
1302 @include decoders.texi
1303 @include encoders.texi
1304 @include demuxers.texi
1305 @include muxers.texi
1306 @include indevs.texi
1307 @include outdevs.texi
1308 @include protocols.texi
1309 @include bitstream_filters.texi
1310 @include filters.texi
1311 @include metadata.texi
1316 @settitle ffmpeg video converter
1318 @c man begin SEEALSO
1319 ffplay(1), ffprobe(1), ffserver(1) and the FFmpeg HTML documentation
1322 @c man begin AUTHORS