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 -timelimit @var{duration} (@emph{global})
720 Exit after ffmpeg has been running for @var{duration} seconds.
721 @item -dump (@emph{global})
722 Dump each input packet to stderr.
723 @item -hex (@emph{global})
724 When dumping packets, also dump the payload.
725 @item -re (@emph{input})
726 Read input at native frame rate. Mainly used to simulate a grab device.
728 Loop over the input stream. Currently it works only for image
729 streams. This option is used for automatic FFserver testing.
730 This option is deprecated, use -loop 1.
731 @item -loop_output @var{number_of_times}
732 Repeatedly loop output for formats that support looping such as animated GIF
733 (0 will loop the output infinitely).
734 This option is deprecated, use -loop.
735 @item -vsync @var{parameter}
737 For compatibility reasons old values can be specified as numbers.
738 Newly added values will have to be specified as strings always.
742 Each frame is passed with its timestamp from the demuxer to the muxer.
744 Frames will be duplicated and dropped to achieve exactly the requested
747 Frames are passed through with their timestamp or dropped so as to
748 prevent 2 frames from having the same timestamp.
750 As passthrough but destroys all timestamps, making the muxer generate
751 fresh timestamps based on frame-rate.
753 Chooses between 1 and 2 depending on muxer capabilities. This is the
757 With -map you can select from which stream the timestamps should be
758 taken. You can leave either video or audio unchanged and sync the
759 remaining stream(s) to the unchanged one.
761 @item -async @var{samples_per_second}
762 Audio sync method. "Stretches/squeezes" the audio stream to match the timestamps,
763 the parameter is the maximum samples per second by which the audio is changed.
764 -async 1 is a special case where only the start of the audio stream is corrected
765 without any later correction.
767 Copy timestamps from input to output.
768 @item -copytb @var{mode}
769 Specify how to set the encoder timebase when stream copying. @var{mode} is an
770 integer numeric value, and can assume one of the following values:
774 Use the demuxer timebase.
776 The time base is copied to the output encoder from the corresponding input
777 demuxer. This is sometimes required to avoid non monotonically increasing
778 timestamps when copying video streams with variable frame rate.
781 Use the decoder timebase.
783 The time base is copied to the output encoder from the corresponding input
787 Try to make the choice automatically, in order to generate a sane output.
793 Finish encoding when the shortest input stream ends.
794 @item -dts_delta_threshold
795 Timestamp discontinuity delta threshold.
796 @item -muxdelay @var{seconds} (@emph{input})
797 Set the maximum demux-decode delay.
798 @item -muxpreload @var{seconds} (@emph{input})
799 Set the initial demux-decode delay.
800 @item -streamid @var{output-stream-index}:@var{new-value} (@emph{output})
801 Assign a new stream-id value to an output stream. This option should be
802 specified prior to the output filename to which it applies.
803 For the situation where multiple output files exist, a streamid
804 may be reassigned to a different value.
806 For example, to set the stream 0 PID to 33 and the stream 1 PID to 36 for
807 an output mpegts file:
809 ffmpeg -i infile -streamid 0:33 -streamid 1:36 out.ts
812 @item -bsf[:@var{stream_specifier}] @var{bitstream_filters} (@emph{output,per-stream})
813 Set bitstream filters for matching streams. @var{bistream_filters} is
814 a comma-separated list of bitstream filters. Use the @code{-bsfs} option
815 to get the list of bitstream filters.
817 ffmpeg -i h264.mp4 -c:v copy -bsf:v h264_mp4toannexb -an out.h264
820 ffmpeg -i file.mov -an -vn -bsf:s mov2textsub -c:s copy -f rawvideo sub.txt
823 @item -tag[:@var{stream_specifier}] @var{codec_tag} (@emph{per-stream})
824 Force a tag/fourcc for matching streams.
826 @item -timecode @var{hh}:@var{mm}:@var{ss}SEP@var{ff}
827 Specify Timecode for writing. @var{SEP} is ':' for non drop timecode and ';'
830 ffmpeg -i input.mpg -timecode 01:02:03.04 -r 30000/1001 -s ntsc output.mpg
834 @section Preset files
835 A preset file contains a sequence of @var{option}=@var{value} pairs,
836 one for each line, specifying a sequence of options which would be
837 awkward to specify on the command line. Lines starting with the hash
838 ('#') character are ignored and are used to provide comments. Check
839 the @file{presets} directory in the FFmpeg source tree for examples.
841 Preset files are specified with the @code{vpre}, @code{apre},
842 @code{spre}, and @code{fpre} options. The @code{fpre} option takes the
843 filename of the preset instead of a preset name as input and can be
844 used for any kind of codec. For the @code{vpre}, @code{apre}, and
845 @code{spre} options, the options specified in a preset file are
846 applied to the currently selected codec of the same type as the preset
849 The argument passed to the @code{vpre}, @code{apre}, and @code{spre}
850 preset options identifies the preset file to use according to the
853 First ffmpeg searches for a file named @var{arg}.ffpreset in the
854 directories @file{$FFMPEG_DATADIR} (if set), and @file{$HOME/.ffmpeg}, and in
855 the datadir defined at configuration time (usually @file{PREFIX/share/ffmpeg})
856 or in a @file{ffpresets} folder along the executable on win32,
857 in that order. For example, if the argument is @code{libx264-max}, it will
858 search for the file @file{libx264-max.ffpreset}.
860 If no such file is found, then ffmpeg will search for a file named
861 @var{codec_name}-@var{arg}.ffpreset in the above-mentioned
862 directories, where @var{codec_name} is the name of the codec to which
863 the preset file options will be applied. For example, if you select
864 the video codec with @code{-vcodec libx264} and use @code{-vpre max},
865 then it will search for the file @file{libx264-max.ffpreset}.
873 For streaming at very low bitrate application, use a low frame rate
874 and a small GOP size. This is especially true for RealVideo where
875 the Linux player does not seem to be very fast, so it can miss
876 frames. An example is:
879 ffmpeg -g 3 -r 3 -t 10 -b:v 50k -s qcif -f rv10 /tmp/b.rm
883 The parameter 'q' which is displayed while encoding is the current
884 quantizer. The value 1 indicates that a very good quality could
885 be achieved. The value 31 indicates the worst quality. If q=31 appears
886 too often, it means that the encoder cannot compress enough to meet
887 your bitrate. You must either increase the bitrate, decrease the
888 frame rate or decrease the frame size.
891 If your computer is not fast enough, you can speed up the
892 compression at the expense of the compression ratio. You can use
893 '-me zero' to speed up motion estimation, and '-intra' to disable
894 motion estimation completely (you have only I-frames, which means it
895 is about as good as JPEG compression).
898 To have very low audio bitrates, reduce the sampling frequency
899 (down to 22050 Hz for MPEG audio, 22050 or 11025 for AC-3).
902 To have a constant quality (but a variable bitrate), use the option
903 '-qscale n' when 'n' is between 1 (excellent quality) and 31 (worst
910 @c man begin EXAMPLES
912 @section Preset files
914 A preset file contains a sequence of @var{option=value} pairs, one for
915 each line, specifying a sequence of options which can be specified also on
916 the command line. Lines starting with the hash ('#') character are ignored and
917 are used to provide comments. Empty lines are also ignored. Check the
918 @file{presets} directory in the FFmpeg source tree for examples.
920 Preset files are specified with the @code{pre} option, this option takes a
921 preset name as input. FFmpeg searches for a file named @var{preset_name}.avpreset in
922 the directories @file{$AVCONV_DATADIR} (if set), and @file{$HOME/.ffmpeg}, and in
923 the data directory defined at configuration time (usually @file{$PREFIX/share/ffmpeg})
924 in that order. For example, if the argument is @code{libx264-max}, it will
925 search for the file @file{libx264-max.avpreset}.
927 @section Video and Audio grabbing
929 If you specify the input format and device then ffmpeg can grab video
933 ffmpeg -f oss -i /dev/dsp -f video4linux2 -i /dev/video0 /tmp/out.mpg
936 Or with an ALSA audio source (mono input, card id 1) instead of OSS:
938 ffmpeg -f alsa -ac 1 -i hw:1 -f video4linux2 -i /dev/video0 /tmp/out.mpg
941 Note that you must activate the right video source and channel before
942 launching ffmpeg with any TV viewer such as
943 @uref{http://linux.bytesex.org/xawtv/, xawtv} by Gerd Knorr. You also
944 have to set the audio recording levels correctly with a
947 @section X11 grabbing
949 Grab the X11 display with ffmpeg via
952 ffmpeg -f x11grab -s cif -r 25 -i :0.0 /tmp/out.mpg
955 0.0 is display.screen number of your X11 server, same as
956 the DISPLAY environment variable.
959 ffmpeg -f x11grab -s cif -r 25 -i :0.0+10,20 /tmp/out.mpg
962 0.0 is display.screen number of your X11 server, same as the DISPLAY environment
963 variable. 10 is the x-offset and 20 the y-offset for the grabbing.
965 @section Video and Audio file format conversion
967 Any supported file format and protocol can serve as input to ffmpeg:
972 You can use YUV files as input:
975 ffmpeg -i /tmp/test%d.Y /tmp/out.mpg
978 It will use the files:
980 /tmp/test0.Y, /tmp/test0.U, /tmp/test0.V,
981 /tmp/test1.Y, /tmp/test1.U, /tmp/test1.V, etc...
984 The Y files use twice the resolution of the U and V files. They are
985 raw files, without header. They can be generated by all decent video
986 decoders. You must specify the size of the image with the @option{-s} option
987 if ffmpeg cannot guess it.
990 You can input from a raw YUV420P file:
993 ffmpeg -i /tmp/test.yuv /tmp/out.avi
996 test.yuv is a file containing raw YUV planar data. Each frame is composed
997 of the Y plane followed by the U and V planes at half vertical and
998 horizontal resolution.
1001 You can output to a raw YUV420P file:
1004 ffmpeg -i mydivx.avi hugefile.yuv
1008 You can set several input files and output files:
1011 ffmpeg -i /tmp/a.wav -s 640x480 -i /tmp/a.yuv /tmp/a.mpg
1014 Converts the audio file a.wav and the raw YUV video file a.yuv
1018 You can also do audio and video conversions at the same time:
1021 ffmpeg -i /tmp/a.wav -ar 22050 /tmp/a.mp2
1024 Converts a.wav to MPEG audio at 22050 Hz sample rate.
1027 You can encode to several formats at the same time and define a
1028 mapping from input stream to output streams:
1031 ffmpeg -i /tmp/a.wav -map 0:a -b:a 64k /tmp/a.mp2 -map 0:a -b:a 128k /tmp/b.mp2
1034 Converts a.wav to a.mp2 at 64 kbits and to b.mp2 at 128 kbits. '-map
1035 file:index' specifies which input stream is used for each output
1036 stream, in the order of the definition of output streams.
1039 You can transcode decrypted VOBs:
1042 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
1045 This is a typical DVD ripping example; the input is a VOB file, the
1046 output an AVI file with MPEG-4 video and MP3 audio. Note that in this
1047 command we use B-frames so the MPEG-4 stream is DivX5 compatible, and
1048 GOP size is 300 which means one intra frame every 10 seconds for 29.97fps
1049 input video. Furthermore, the audio stream is MP3-encoded so you need
1050 to enable LAME support by passing @code{--enable-libmp3lame} to configure.
1051 The mapping is particularly useful for DVD transcoding
1052 to get the desired audio language.
1054 NOTE: To see the supported input formats, use @code{ffmpeg -formats}.
1057 You can extract images from a video, or create a video from many images:
1059 For extracting images from a video:
1061 ffmpeg -i foo.avi -r 1 -s WxH -f image2 foo-%03d.jpeg
1064 This will extract one video frame per second from the video and will
1065 output them in files named @file{foo-001.jpeg}, @file{foo-002.jpeg},
1066 etc. Images will be rescaled to fit the new WxH values.
1068 If you want to extract just a limited number of frames, you can use the
1069 above command in combination with the -vframes or -t option, or in
1070 combination with -ss to start extracting from a certain point in time.
1072 For creating a video from many images:
1074 ffmpeg -f image2 -i foo-%03d.jpeg -r 12 -s WxH foo.avi
1077 The syntax @code{foo-%03d.jpeg} specifies to use a decimal number
1078 composed of three digits padded with zeroes to express the sequence
1079 number. It is the same syntax supported by the C printf function, but
1080 only formats accepting a normal integer are suitable.
1082 When importing an image sequence, -i also supports expanding shell-like
1083 wildcard patterns (globbing) internally. To lower the chance of interfering
1084 with your actual file names and the shell's glob expansion, you are required
1085 to activate glob meta characters by prefixing them with a single @code{%}
1086 character, like in @code{foo-%*.jpeg}, @code{foo-%?%?%?.jpeg} or
1087 @code{foo-00%[234%]%*.jpeg}.
1088 If your filename actually contains a character sequence of a @code{%} character
1089 followed by a glob character, you must double the @code{%} character to escape
1090 it. Imagine your files begin with @code{%?-foo-}, then you could use a glob
1091 pattern like @code{%%?-foo-%*.jpeg}. For input patterns that could be both a
1092 printf or a glob pattern, ffmpeg will assume it is a glob pattern.
1095 You can put many streams of the same type in the output:
1098 ffmpeg -i test1.avi -i test2.avi -map 0.3 -map 0.2 -map 0.1 -map 0.0 -c copy test12.nut
1101 The resulting output file @file{test12.avi} will contain first four streams from
1102 the input file in reverse order.
1105 To force CBR video output:
1107 ffmpeg -i myfile.avi -b 4000k -minrate 4000k -maxrate 4000k -bufsize 1835k out.m2v
1111 The four options lmin, lmax, mblmin and mblmax use 'lambda' units,
1112 but you may use the QP2LAMBDA constant to easily convert from 'q' units:
1114 ffmpeg -i src.ext -lmax 21*QP2LAMBDA dst.ext
1121 @include decoders.texi
1122 @include encoders.texi
1123 @include demuxers.texi
1124 @include muxers.texi
1125 @include indevs.texi
1126 @include outdevs.texi
1127 @include protocols.texi
1128 @include bitstream_filters.texi
1129 @include filters.texi
1130 @include metadata.texi
1135 @settitle ffmpeg video converter
1137 @c man begin SEEALSO
1138 ffplay(1), ffprobe(1), ffserver(1) and the FFmpeg HTML documentation
1141 @c man begin AUTHORS