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.
374 @item -vcodec @var{codec} (@emph{output})
375 Set the video codec. This is an alias for @code{-codec:v}.
377 Use same quantizer as source (implies VBR).
379 Note that this is NOT SAME QUALITY. Do not use this option unless you know you
383 Select the pass number (1 or 2). It is used to do two-pass
384 video encoding. The statistics of the video are recorded in the first
385 pass into a log file (see also the option -passlogfile),
386 and in the second pass that log file is used to generate the video
387 at the exact requested bitrate.
388 On pass 1, you may just deactivate audio and set output to null,
389 examples for Windows and Unix:
391 ffmpeg -i foo.mov -c:v libxvid -pass 1 -an -f rawvideo -y NUL
392 ffmpeg -i foo.mov -c:v libxvid -pass 1 -an -f rawvideo -y /dev/null
395 @item -passlogfile @var{prefix} (@emph{global})
396 Set two-pass log file name prefix to @var{prefix}, the default file name
397 prefix is ``ffmpeg2pass''. The complete file name will be
398 @file{PREFIX-N.log}, where N is a number specific to the output
401 @item -vlang @var{code}
402 Set the ISO 639 language code (3 letters) of the current video stream.
404 @item -vf @var{filter_graph} (@emph{output})
405 @var{filter_graph} is a description of the filter graph to apply to
407 Use the option "-filters" to show all the available filters (including
408 also sources and sinks). This is an alias for @code{-filter:v}.
412 @section Advanced Video Options
415 @item -pix_fmt[:@var{stream_specifier}] @var{format} (@emph{input/output,per-stream})
416 Set pixel format. Use @code{-pix_fmts} to show all the supported
418 @item -sws_flags @var{flags} (@emph{input/output})
423 @item -rc_override[:@var{stream_specifier}] @var{override} (@emph{output,per-stream})
424 Rate control override for specific intervals, formatted as "int,int,int"
425 list separated with slashes. Two first values are the beginning and
426 end frame numbers, last one is quantizer to use if positive, or quality
430 Deinterlace pictures.
431 This option is deprecated since the deinterlacing is very low quality.
432 Use the yadif filter with @code{-filter:v yadif}.
434 Force interlacing support in encoder (MPEG-2 and MPEG-4 only).
435 Use this option if your input file is interlaced and you want
436 to keep the interlaced format for minimum losses.
437 The alternative is to deinterlace the input stream with
438 @option{-deinterlace}, but deinterlacing introduces losses.
440 Calculate PSNR of compressed frames.
442 Dump video coding statistics to @file{vstats_HHMMSS.log}.
443 @item -vstats_file @var{file}
444 Dump video coding statistics to @var{file}.
445 @item -top[:@var{stream_specifier}] @var{n} (@emph{output,per-stream})
446 top=1/bottom=0/auto=-1 field first
447 @item -dc @var{precision}
449 @item -vtag @var{fourcc/tag} (@emph{output})
450 Force video tag/fourcc. This is an alias for @code{-tag:v}.
451 @item -qphist (@emph{global})
453 @item -vbsf @var{bitstream_filter}
455 @item -force_key_frames[:@var{stream_specifier}] @var{time}[,@var{time}...] (@emph{output,per-stream})
456 Force key frames at the specified timestamps, more precisely at the first
457 frames after each specified time.
458 This option can be useful to ensure that a seek point is present at a
459 chapter mark or any other designated place in the output file.
460 The timestamps must be specified in ascending order.
462 @item -copyinkf[:@var{stream_specifier}] (@emph{output,per-stream})
463 When doing stream copy, copy also non-key frames found at the
467 @section Audio Options
470 @item -aframes @var{number} (@emph{output})
471 Set the number of audio frames to record. This is an alias for @code{-frames:a}.
472 @item -ar[:@var{stream_specifier}] @var{freq} (@emph{input/output,per-stream})
473 Set the audio sampling frequency. For output streams it is set by
474 default to the frequency of the corresponding input stream. For input
475 streams this option only makes sense for audio grabbing devices and raw
476 demuxers and is mapped to the corresponding demuxer options.
477 @item -aq @var{q} (@emph{output})
478 Set the audio quality (codec-specific, VBR). This is an alias for -q:a.
479 @item -ac[:@var{stream_specifier}] @var{channels} (@emph{input/output,per-stream})
480 Set the number of audio channels. For output streams it is set by
481 default to the number of input audio channels. For input streams
482 this option only makes sense for audio grabbing devices and raw demuxers
483 and is mapped to the corresponding demuxer options.
484 @item -an (@emph{output})
485 Disable audio recording.
486 @item -acodec @var{codec} (@emph{input/output})
487 Set the audio codec. This is an alias for @code{-codec:a}.
488 @item -sample_fmt[:@var{stream_specifier}] @var{sample_fmt} (@emph{output,per-stream})
489 Set the audio sample format. Use @code{-sample_fmts} to get a list
490 of supported sample formats.
493 @section Advanced Audio options:
496 @item -atag @var{fourcc/tag} (@emph{output})
497 Force audio tag/fourcc. This is an alias for @code{-tag:a}.
498 @item -absf @var{bitstream_filter}
502 @section Subtitle options:
505 @item -slang @var{code}
506 Set the ISO 639 language code (3 letters) of the current subtitle stream.
507 @item -scodec @var{codec} (@emph{input/output})
508 Set the subtitle codec. This is an alias for @code{-codec:s}.
509 @item -sn (@emph{output})
510 Disable subtitle recording.
511 @item -sbsf @var{bitstream_filter}
515 @section Audio/Video grab options
518 @item -isync (@emph{global})
519 Synchronize read on input.
522 @section Advanced options
525 @item -map [-]@var{input_file_id}[:@var{stream_specifier}][,@var{sync_file_id}[:@var{stream_specifier}]] (@emph{output})
527 Designate one or more input streams as a source for the output file. Each input
528 stream is identified by the input file index @var{input_file_id} and
529 the input stream index @var{input_stream_id} within the input
530 file. Both indices start at 0. If specified,
531 @var{sync_file_id}:@var{stream_specifier} sets which input stream
532 is used as a presentation sync reference.
534 The first @code{-map} option on the command line specifies the
535 source for output stream 0, the second @code{-map} option specifies
536 the source for output stream 1, etc.
538 A @code{-} character before the stream identifier creates a "negative" mapping.
539 It disables matching streams from already created mappings.
541 For example, to map ALL streams from the first input file to output
543 ffmpeg -i INPUT -map 0 output
546 For example, if you have two audio streams in the first input file,
547 these streams are identified by "0:0" and "0:1". You can use
548 @code{-map} to select which streams to place in an output file. For
551 ffmpeg -i INPUT -map 0:1 out.wav
553 will map the input stream in @file{INPUT} identified by "0:1" to
554 the (single) output stream in @file{out.wav}.
556 For example, to select the stream with index 2 from input file
557 @file{a.mov} (specified by the identifier "0:2"), and stream with
558 index 6 from input @file{b.mov} (specified by the identifier "1:6"),
559 and copy them to the output file @file{out.mov}:
561 ffmpeg -i a.mov -i b.mov -c copy -map 0:2 -map 1:6 out.mov
564 To select all video and the third audio stream from an input file:
566 ffmpeg -i INPUT -map 0:v -map 0:a:2 OUTPUT
569 To map all the streams except the second audio, use negative mappings
571 ffmpeg -i INPUT -map 0 -map -0:a:1 OUTPUT
574 Note that using this option disables the default mappings for this output file.
576 @item -map_channel [@var{input_file_id}.@var{stream_specifier}.@var{channel_id}|-1][:@var{output_file_id}.@var{stream_specifier}]
577 Map an audio channel from a given input to an output. If
578 @var{output_file_id}.@var{stream_specifier} is not set, the audio channel will
579 be mapped on all the audio streams.
581 Using "-1" instead of
582 @var{input_file_id}.@var{stream_specifier}.@var{channel_id} will map a muted
585 For example, assuming @var{INPUT} is a stereo audio file, you can switch the
586 two audio channels with the following command:
588 ffmpeg -i INPUT -map_channel 0.0.1 -map_channel 0.0.0 OUTPUT
591 If you want to mute the first channel and keep the second:
593 ffmpeg -i INPUT -map_channel -1 -map_channel 0.0.1 OUTPUT
596 The order of the "-map_channel" option specifies the order of the channels in
597 the output stream. The output channel layout is guessed from the number of
598 channels mapped (mono if one "-map_channel", stereo if two, etc.). Using "-ac"
599 in combination of "-map_channel" makes the channel gain levels to be updated if
600 input and output channel layouts don't match (for instance two "-map_channel"
601 options and "-ac 6").
603 You can also extract each channel of an input to specific outputs; the following
604 command extracts two channels of the @var{INPUT} audio stream (file 0, stream 0)
605 to the respective @var{OUTPUT_CH0} and @var{OUTPUT_CH1} outputs:
607 ffmpeg -i INPUT -map_channel 0.0.0 OUTPUT_CH0 -map_channel 0.0.1 OUTPUT_CH1
610 The following example splits the channels of a stereo input into two separate
611 streams, which are put into the same output file:
613 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
616 Note that currently each output stream can only contain channels from a single
617 input stream; you can't for example use "-map_channel" to pick multiple input
618 audio channels contained in different streams (from the same or different files)
619 and merge them into a single output stream. It is therefore not currently
620 possible, for example, to turn two separate mono streams into a single stereo
621 stream. However splitting a stereo stream into two single channel mono streams
624 If you need this feature, a possible workaround is to use the @emph{amerge}
625 filter. For example, if you need to merge a media (here @file{input.mkv}) with 2
626 mono audio streams into one single stereo channel audio stream (and keep the
627 video stream), you can use the following command:
629 ffmpeg -i input.mkv -f lavfi -i "
630 amovie=input.mkv:si=1 [a1];
631 amovie=input.mkv:si=2 [a2];
632 [a1][a2] amerge" -c:a pcm_s16le -c:v copy output.mkv
635 @item -map_metadata[:@var{metadata_spec_out}] @var{infile}[:@var{metadata_spec_in}] (@emph{output,per-metadata})
636 Set metadata information of the next output file from @var{infile}. Note that
637 those are file indices (zero-based), not filenames.
638 Optional @var{metadata_spec_in/out} parameters specify, which metadata to copy.
639 A metadata specifier can have the following forms:
642 global metadata, i.e. metadata that applies to the whole file
644 @item @var{s}[:@var{stream_spec}]
645 per-stream metadata. @var{stream_spec} is a stream specifier as described
646 in the @ref{Stream specifiers} chapter. In an input metadata specifier, the first
647 matching stream is copied from. In an output metadata specifier, all matching
648 streams are copied to.
650 @item @var{c}:@var{chapter_index}
651 per-chapter metadata. @var{chapter_index} is the zero-based chapter index.
653 @item @var{p}:@var{program_index}
654 per-program metadata. @var{program_index} is the zero-based program index.
656 If metadata specifier is omitted, it defaults to global.
658 By default, global metadata is copied from the first input file,
659 per-stream and per-chapter metadata is copied along with streams/chapters. These
660 default mappings are disabled by creating any mapping of the relevant type. A negative
661 file index can be used to create a dummy mapping that just disables automatic copying.
663 For example to copy metadata from the first stream of the input file to global metadata
666 ffmpeg -i in.ogg -map_metadata 0:s:0 out.mp3
669 To do the reverse, i.e. copy global metadata to all audio streams:
671 ffmpeg -i in.mkv -map_metadata:s:a 0:g out.mkv
673 Note that simple @code{0} would work as well in this example, since global
674 metadata is assumed by default.
676 @item -map_chapters @var{input_file_index} (@emph{output})
677 Copy chapters from input file with index @var{input_file_index} to the next
678 output file. If no chapter mapping is specified, then chapters are copied from
679 the first input file with at least one chapter. Use a negative file index to
680 disable any chapter copying.
681 @item -debug @var{category}
682 Print specific debug info.
683 @var{category} is a number or a string containing one of the following values:
687 picture buffer allocations
695 memory management control operations (H.264)
702 per-block quantization parameter (QP)
710 visualize block types
712 visualize quantization parameter (QP), lower QP are tinted greener
714 @item -benchmark (@emph{global})
715 Show benchmarking information at the end of an encode.
716 Shows CPU time used and maximum memory consumption.
717 Maximum memory consumption is not supported on all systems,
718 it will usually display as 0 if not supported.
719 @item -benchmark_all (@emph{global})
720 Show benchmarking information during the encode.
721 Shows CPU time used in various steps (audio/video encode/decode).
722 @item -timelimit @var{duration} (@emph{global})
723 Exit after ffmpeg has been running for @var{duration} seconds.
724 @item -dump (@emph{global})
725 Dump each input packet to stderr.
726 @item -hex (@emph{global})
727 When dumping packets, also dump the payload.
728 @item -re (@emph{input})
729 Read input at native frame rate. Mainly used to simulate a grab device.
731 Loop over the input stream. Currently it works only for image
732 streams. This option is used for automatic FFserver testing.
733 This option is deprecated, use -loop 1.
734 @item -loop_output @var{number_of_times}
735 Repeatedly loop output for formats that support looping such as animated GIF
736 (0 will loop the output infinitely).
737 This option is deprecated, use -loop.
738 @item -vsync @var{parameter}
740 For compatibility reasons old values can be specified as numbers.
741 Newly added values will have to be specified as strings always.
745 Each frame is passed with its timestamp from the demuxer to the muxer.
747 Frames will be duplicated and dropped to achieve exactly the requested
750 Frames are passed through with their timestamp or dropped so as to
751 prevent 2 frames from having the same timestamp.
753 As passthrough but destroys all timestamps, making the muxer generate
754 fresh timestamps based on frame-rate.
756 Chooses between 1 and 2 depending on muxer capabilities. This is the
760 With -map you can select from which stream the timestamps should be
761 taken. You can leave either video or audio unchanged and sync the
762 remaining stream(s) to the unchanged one.
764 @item -async @var{samples_per_second}
765 Audio sync method. "Stretches/squeezes" the audio stream to match the timestamps,
766 the parameter is the maximum samples per second by which the audio is changed.
767 -async 1 is a special case where only the start of the audio stream is corrected
768 without any later correction.
770 Copy timestamps from input to output.
771 @item -copytb @var{mode}
772 Specify how to set the encoder timebase when stream copying. @var{mode} is an
773 integer numeric value, and can assume one of the following values:
777 Use the demuxer timebase.
779 The time base is copied to the output encoder from the corresponding input
780 demuxer. This is sometimes required to avoid non monotonically increasing
781 timestamps when copying video streams with variable frame rate.
784 Use the decoder timebase.
786 The time base is copied to the output encoder from the corresponding input
790 Try to make the choice automatically, in order to generate a sane output.
796 Finish encoding when the shortest input stream ends.
797 @item -dts_delta_threshold
798 Timestamp discontinuity delta threshold.
799 @item -muxdelay @var{seconds} (@emph{input})
800 Set the maximum demux-decode delay.
801 @item -muxpreload @var{seconds} (@emph{input})
802 Set the initial demux-decode delay.
803 @item -streamid @var{output-stream-index}:@var{new-value} (@emph{output})
804 Assign a new stream-id value to an output stream. This option should be
805 specified prior to the output filename to which it applies.
806 For the situation where multiple output files exist, a streamid
807 may be reassigned to a different value.
809 For example, to set the stream 0 PID to 33 and the stream 1 PID to 36 for
810 an output mpegts file:
812 ffmpeg -i infile -streamid 0:33 -streamid 1:36 out.ts
815 @item -bsf[:@var{stream_specifier}] @var{bitstream_filters} (@emph{output,per-stream})
816 Set bitstream filters for matching streams. @var{bistream_filters} is
817 a comma-separated list of bitstream filters. Use the @code{-bsfs} option
818 to get the list of bitstream filters.
820 ffmpeg -i h264.mp4 -c:v copy -bsf:v h264_mp4toannexb -an out.h264
823 ffmpeg -i file.mov -an -vn -bsf:s mov2textsub -c:s copy -f rawvideo sub.txt
826 @item -tag[:@var{stream_specifier}] @var{codec_tag} (@emph{per-stream})
827 Force a tag/fourcc for matching streams.
829 @item -timecode @var{hh}:@var{mm}:@var{ss}SEP@var{ff}
830 Specify Timecode for writing. @var{SEP} is ':' for non drop timecode and ';'
833 ffmpeg -i input.mpg -timecode 01:02:03.04 -r 30000/1001 -s ntsc output.mpg
837 @section Preset files
838 A preset file contains a sequence of @var{option}=@var{value} pairs,
839 one for each line, specifying a sequence of options which would be
840 awkward to specify on the command line. Lines starting with the hash
841 ('#') character are ignored and are used to provide comments. Check
842 the @file{presets} directory in the FFmpeg source tree for examples.
844 Preset files are specified with the @code{vpre}, @code{apre},
845 @code{spre}, and @code{fpre} options. The @code{fpre} option takes the
846 filename of the preset instead of a preset name as input and can be
847 used for any kind of codec. For the @code{vpre}, @code{apre}, and
848 @code{spre} options, the options specified in a preset file are
849 applied to the currently selected codec of the same type as the preset
852 The argument passed to the @code{vpre}, @code{apre}, and @code{spre}
853 preset options identifies the preset file to use according to the
856 First ffmpeg searches for a file named @var{arg}.ffpreset in the
857 directories @file{$FFMPEG_DATADIR} (if set), and @file{$HOME/.ffmpeg}, and in
858 the datadir defined at configuration time (usually @file{PREFIX/share/ffmpeg})
859 or in a @file{ffpresets} folder along the executable on win32,
860 in that order. For example, if the argument is @code{libx264-max}, it will
861 search for the file @file{libx264-max.ffpreset}.
863 If no such file is found, then ffmpeg will search for a file named
864 @var{codec_name}-@var{arg}.ffpreset in the above-mentioned
865 directories, where @var{codec_name} is the name of the codec to which
866 the preset file options will be applied. For example, if you select
867 the video codec with @code{-vcodec libx264} and use @code{-vpre max},
868 then it will search for the file @file{libx264-max.ffpreset}.
876 For streaming at very low bitrate application, use a low frame rate
877 and a small GOP size. This is especially true for RealVideo where
878 the Linux player does not seem to be very fast, so it can miss
879 frames. An example is:
882 ffmpeg -g 3 -r 3 -t 10 -b:v 50k -s qcif -f rv10 /tmp/b.rm
886 The parameter 'q' which is displayed while encoding is the current
887 quantizer. The value 1 indicates that a very good quality could
888 be achieved. The value 31 indicates the worst quality. If q=31 appears
889 too often, it means that the encoder cannot compress enough to meet
890 your bitrate. You must either increase the bitrate, decrease the
891 frame rate or decrease the frame size.
894 If your computer is not fast enough, you can speed up the
895 compression at the expense of the compression ratio. You can use
896 '-me zero' to speed up motion estimation, and '-intra' to disable
897 motion estimation completely (you have only I-frames, which means it
898 is about as good as JPEG compression).
901 To have very low audio bitrates, reduce the sampling frequency
902 (down to 22050 Hz for MPEG audio, 22050 or 11025 for AC-3).
905 To have a constant quality (but a variable bitrate), use the option
906 '-qscale n' when 'n' is between 1 (excellent quality) and 31 (worst
913 @c man begin EXAMPLES
915 @section Preset files
917 A preset file contains a sequence of @var{option=value} pairs, one for
918 each line, specifying a sequence of options which can be specified also on
919 the command line. Lines starting with the hash ('#') character are ignored and
920 are used to provide comments. Empty lines are also ignored. Check the
921 @file{presets} directory in the FFmpeg source tree for examples.
923 Preset files are specified with the @code{pre} option, this option takes a
924 preset name as input. FFmpeg searches for a file named @var{preset_name}.avpreset in
925 the directories @file{$AVCONV_DATADIR} (if set), and @file{$HOME/.ffmpeg}, and in
926 the data directory defined at configuration time (usually @file{$PREFIX/share/ffmpeg})
927 in that order. For example, if the argument is @code{libx264-max}, it will
928 search for the file @file{libx264-max.avpreset}.
930 @section Video and Audio grabbing
932 If you specify the input format and device then ffmpeg can grab video
936 ffmpeg -f oss -i /dev/dsp -f video4linux2 -i /dev/video0 /tmp/out.mpg
939 Or with an ALSA audio source (mono input, card id 1) instead of OSS:
941 ffmpeg -f alsa -ac 1 -i hw:1 -f video4linux2 -i /dev/video0 /tmp/out.mpg
944 Note that you must activate the right video source and channel before
945 launching ffmpeg with any TV viewer such as
946 @uref{http://linux.bytesex.org/xawtv/, xawtv} by Gerd Knorr. You also
947 have to set the audio recording levels correctly with a
950 @section X11 grabbing
952 Grab the X11 display with ffmpeg via
955 ffmpeg -f x11grab -s cif -r 25 -i :0.0 /tmp/out.mpg
958 0.0 is display.screen number of your X11 server, same as
959 the DISPLAY environment variable.
962 ffmpeg -f x11grab -s cif -r 25 -i :0.0+10,20 /tmp/out.mpg
965 0.0 is display.screen number of your X11 server, same as the DISPLAY environment
966 variable. 10 is the x-offset and 20 the y-offset for the grabbing.
968 @section Video and Audio file format conversion
970 Any supported file format and protocol can serve as input to ffmpeg:
975 You can use YUV files as input:
978 ffmpeg -i /tmp/test%d.Y /tmp/out.mpg
981 It will use the files:
983 /tmp/test0.Y, /tmp/test0.U, /tmp/test0.V,
984 /tmp/test1.Y, /tmp/test1.U, /tmp/test1.V, etc...
987 The Y files use twice the resolution of the U and V files. They are
988 raw files, without header. They can be generated by all decent video
989 decoders. You must specify the size of the image with the @option{-s} option
990 if ffmpeg cannot guess it.
993 You can input from a raw YUV420P file:
996 ffmpeg -i /tmp/test.yuv /tmp/out.avi
999 test.yuv is a file containing raw YUV planar data. Each frame is composed
1000 of the Y plane followed by the U and V planes at half vertical and
1001 horizontal resolution.
1004 You can output to a raw YUV420P file:
1007 ffmpeg -i mydivx.avi hugefile.yuv
1011 You can set several input files and output files:
1014 ffmpeg -i /tmp/a.wav -s 640x480 -i /tmp/a.yuv /tmp/a.mpg
1017 Converts the audio file a.wav and the raw YUV video file a.yuv
1021 You can also do audio and video conversions at the same time:
1024 ffmpeg -i /tmp/a.wav -ar 22050 /tmp/a.mp2
1027 Converts a.wav to MPEG audio at 22050 Hz sample rate.
1030 You can encode to several formats at the same time and define a
1031 mapping from input stream to output streams:
1034 ffmpeg -i /tmp/a.wav -map 0:a -b:a 64k /tmp/a.mp2 -map 0:a -b:a 128k /tmp/b.mp2
1037 Converts a.wav to a.mp2 at 64 kbits and to b.mp2 at 128 kbits. '-map
1038 file:index' specifies which input stream is used for each output
1039 stream, in the order of the definition of output streams.
1042 You can transcode decrypted VOBs:
1045 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
1048 This is a typical DVD ripping example; the input is a VOB file, the
1049 output an AVI file with MPEG-4 video and MP3 audio. Note that in this
1050 command we use B-frames so the MPEG-4 stream is DivX5 compatible, and
1051 GOP size is 300 which means one intra frame every 10 seconds for 29.97fps
1052 input video. Furthermore, the audio stream is MP3-encoded so you need
1053 to enable LAME support by passing @code{--enable-libmp3lame} to configure.
1054 The mapping is particularly useful for DVD transcoding
1055 to get the desired audio language.
1057 NOTE: To see the supported input formats, use @code{ffmpeg -formats}.
1060 You can extract images from a video, or create a video from many images:
1062 For extracting images from a video:
1064 ffmpeg -i foo.avi -r 1 -s WxH -f image2 foo-%03d.jpeg
1067 This will extract one video frame per second from the video and will
1068 output them in files named @file{foo-001.jpeg}, @file{foo-002.jpeg},
1069 etc. Images will be rescaled to fit the new WxH values.
1071 If you want to extract just a limited number of frames, you can use the
1072 above command in combination with the -vframes or -t option, or in
1073 combination with -ss to start extracting from a certain point in time.
1075 For creating a video from many images:
1077 ffmpeg -f image2 -i foo-%03d.jpeg -r 12 -s WxH foo.avi
1080 The syntax @code{foo-%03d.jpeg} specifies to use a decimal number
1081 composed of three digits padded with zeroes to express the sequence
1082 number. It is the same syntax supported by the C printf function, but
1083 only formats accepting a normal integer are suitable.
1085 When importing an image sequence, -i also supports expanding shell-like
1086 wildcard patterns (globbing) internally. To lower the chance of interfering
1087 with your actual file names and the shell's glob expansion, you are required
1088 to activate glob meta characters by prefixing them with a single @code{%}
1089 character, like in @code{foo-%*.jpeg}, @code{foo-%?%?%?.jpeg} or
1090 @code{foo-00%[234%]%*.jpeg}.
1091 If your filename actually contains a character sequence of a @code{%} character
1092 followed by a glob character, you must double the @code{%} character to escape
1093 it. Imagine your files begin with @code{%?-foo-}, then you could use a glob
1094 pattern like @code{%%?-foo-%*.jpeg}. For input patterns that could be both a
1095 printf or a glob pattern, ffmpeg will assume it is a glob pattern.
1098 You can put many streams of the same type in the output:
1101 ffmpeg -i test1.avi -i test2.avi -map 0.3 -map 0.2 -map 0.1 -map 0.0 -c copy test12.nut
1104 The resulting output file @file{test12.avi} will contain first four streams from
1105 the input file in reverse order.
1108 To force CBR video output:
1110 ffmpeg -i myfile.avi -b 4000k -minrate 4000k -maxrate 4000k -bufsize 1835k out.m2v
1114 The four options lmin, lmax, mblmin and mblmax use 'lambda' units,
1115 but you may use the QP2LAMBDA constant to easily convert from 'q' units:
1117 ffmpeg -i src.ext -lmax 21*QP2LAMBDA dst.ext
1124 @include decoders.texi
1125 @include encoders.texi
1126 @include demuxers.texi
1127 @include muxers.texi
1128 @include indevs.texi
1129 @include outdevs.texi
1130 @include protocols.texi
1131 @include bitstream_filters.texi
1132 @include filters.texi
1133 @include metadata.texi
1138 @settitle ffmpeg video converter
1140 @c man begin SEEALSO
1141 ffplay(1), ffprobe(1), ffserver(1) and the FFmpeg HTML documentation
1144 @c man begin AUTHORS