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 -bufsize 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 Detailed description
83 @c man begin DETAILED DESCRIPTION
85 The transcoding process in @command{ffmpeg} for each output can be described by
86 the following diagram:
89 _______ ______________ _________ ______________ ________
91 | input | demuxer | encoded data | decoder | decoded | encoder | encoded data | muxer | output |
92 | file | ---------> | packets | ---------> | frames | ---------> | packets | -------> | file |
93 |_______| |______________| |_________| |______________| |________|
97 @command{ffmpeg} calls the libavformat library (containing demuxers) to read
98 input files and get packets containing encoded data from them. When there are
99 multiple input files, @command{ffmpeg} tries to keep them synchronized by
100 tracking lowest timestamp on any active input stream.
102 Encoded packets are then passed to the decoder (unless streamcopy is selected
103 for the stream, see further for a description). The decoder produces
104 uncompressed frames (raw video/PCM audio/...) which can be processed further by
105 filtering (see next section). After filtering the frames are passed to the
106 encoder, which encodes them and outputs encoded packets again. Finally those are
107 passed to the muxer, which writes the encoded packets to the output file.
110 Before encoding, @command{ffmpeg} can process raw audio and video frames using
111 filters from the libavfilter library. Several chained filters form a filter
112 graph. @command{ffmpeg} distinguishes between two types of filtergraphs -
115 @subsection Simple filtergraphs
116 Simple filtergraphs are those that have exactly one input and output, both of
117 the same type. In the above diagram they can be represented by simply inserting
118 an additional step between decoding and encoding:
121 _________ __________ ______________
123 | decoded | simple filtergraph | filtered | encoder | encoded data |
124 | frames | -------------------> | frames | ---------> | packets |
125 |_________| |__________| |______________|
129 Simple filtergraphs are configured with the per-stream @option{-filter} option
130 (with @option{-vf} and @option{-af} aliases for video and audio respectively).
131 A simple filtergraph for video can look for example like this:
134 _______ _____________ _______ _____ ________
136 | input | ---> | deinterlace | ---> | scale | ---> | fps | ---> | output |
137 |_______| |_____________| |_______| |_____| |________|
141 Note that some filters change frame properties but not frame contents. E.g. the
142 @code{fps} filter in the example above changes number of frames, but does not
143 touch the frame contents. Another example is the @code{setpts} filter, which
144 only sets timestamps and otherwise passes the frames unchanged.
146 @subsection Complex filtergraphs
147 Complex filtergraphs are those which cannot be described as simply a linear
148 processing chain applied to one stream. This is the case e.g. when the graph has
149 more than one input and/or output, or when output stream type is different from
150 input. They can be represented with the following diagram:
155 | input 0 |\ __________
157 \ _________ /| output 0 |
159 _________ \| complex | /
161 | input 1 |---->| filter |\
162 |_________| | | \ __________
165 _________ / |_________| |__________|
172 Complex filtergraphs are configured with the @option{-filter_complex} option.
173 Note that this option is global, since a complex filtergraph by its nature
174 cannot be unambiguously associated with a single stream or file.
176 A trivial example of a complex filtergraph is the @code{overlay} filter, which
177 has two video inputs and one video output, containing one video overlaid on top
178 of the other. Its audio counterpart is the @code{amix} filter.
181 Stream copy is a mode selected by supplying the @code{copy} parameter to the
182 @option{-codec} option. It makes @command{ffmpeg} omit the decoding and encoding
183 step for the specified stream, so it does only demuxing and muxing. It is useful
184 for changing the container format or modifying container-level metadata. The
185 diagram above will in this case simplify to this:
188 _______ ______________ ________
190 | input | demuxer | encoded data | muxer | output |
191 | file | ---------> | packets | -------> | file |
192 |_______| |______________| |________|
196 Since there is no decoding or encoding, it is very fast and there is no quality
197 loss. However it might not work in some cases because of many factors. Applying
198 filters is obviously also impossible, since filters work on uncompressed data.
200 @c man end DETAILED DESCRIPTION
202 @chapter Stream selection
203 @c man begin STREAM SELECTION
205 By default ffmpeg includes only one stream of each type (video, audio, subtitle)
206 present in the input files and adds them to each output file. It picks the
207 "best" of each based upon the following criteria; for video it is the stream
208 with the highest resolution, for audio the stream with the most channels, for
209 subtitle it's the first subtitle stream. In the case where several streams of
210 the same type rate equally, the lowest numbered stream is chosen.
212 You can disable some of those defaults by using @code{-vn/-an/-sn} options. For
213 full manual control, use the @code{-map} option, which disables the defaults just
216 @c man end STREAM SELECTION
221 @include avtools-common-opts.texi
223 @section Main options
227 @item -f @var{fmt} (@emph{input/output})
228 Force input or output file format. The format is normally auto detected for input
229 files and guessed from file extension for output files, so this option is not
230 needed in most cases.
232 @item -i @var{filename} (@emph{input})
235 @item -y (@emph{global})
236 Overwrite output files without asking.
238 @item -n (@emph{global})
239 Do not overwrite output files but exit if file exists.
241 @item -c[:@var{stream_specifier}] @var{codec} (@emph{input/output,per-stream})
242 @itemx -codec[:@var{stream_specifier}] @var{codec} (@emph{input/output,per-stream})
243 Select an encoder (when used before an output file) or a decoder (when used
244 before an input file) for one or more streams. @var{codec} is the name of a
245 decoder/encoder or a special value @code{copy} (output only) to indicate that
246 the stream is not to be re-encoded.
250 ffmpeg -i INPUT -map 0 -c:v libx264 -c:a copy OUTPUT
252 encodes all video streams with libx264 and copies all audio streams.
254 For each stream, the last matching @code{c} option is applied, so
256 ffmpeg -i INPUT -map 0 -c copy -c:v:1 libx264 -c:a:137 libvorbis OUTPUT
258 will copy all the streams except the second video, which will be encoded with
259 libx264, and the 138th audio, which will be encoded with libvorbis.
261 @item -t @var{duration} (@emph{output})
262 Stop writing the output after its duration reaches @var{duration}.
263 @var{duration} may be a number in seconds, or in @code{hh:mm:ss[.xxx]} form.
265 @item -fs @var{limit_size} (@emph{output})
266 Set the file size limit, expressed in bytes.
268 @item -ss @var{position} (@emph{input/output})
269 When used as an input option (before @code{-i}), seeks in this input file to
270 @var{position}. When used as an output option (before an output filename),
271 decodes but discards input until the timestamps reach @var{position}. This is
272 slower, but more accurate.
274 @var{position} may be either in seconds or in @code{hh:mm:ss[.xxx]} form.
276 @item -itsoffset @var{offset} (@emph{input})
277 Set the input time offset in seconds.
278 @code{[-]hh:mm:ss[.xxx]} syntax is also supported.
279 The offset is added to the timestamps of the input files.
280 Specifying a positive offset means that the corresponding
281 streams are delayed by @var{offset} seconds.
283 @item -timestamp @var{time} (@emph{output})
284 Set the recording timestamp in the container.
285 The syntax for @var{time} is:
287 now|([(YYYY-MM-DD|YYYYMMDD)[T|t| ]]((HH:MM:SS[.m...])|(HHMMSS[.m...]))[Z|z])
289 If the value is "now" it takes the current time.
290 Time is local time unless 'Z' or 'z' is appended, in which case it is
292 If the year-month-day part is not specified it takes the current
295 @item -metadata[:metadata_specifier] @var{key}=@var{value} (@emph{output,per-metadata})
296 Set a metadata key/value pair.
298 An optional @var{metadata_specifier} may be given to set metadata
299 on streams or chapters. See @code{-map_metadata} documentation for
302 This option overrides metadata set with @code{-map_metadata}. It is
303 also possible to delete metadata by using an empty value.
305 For example, for setting the title in the output file:
307 ffmpeg -i in.avi -metadata title="my title" out.flv
310 To set the language of the first audio stream:
312 ffmpeg -i INPUT -metadata:s:a:1 language=eng OUTPUT
315 @item -target @var{type} (@emph{output})
316 Specify target file type (@code{vcd}, @code{svcd}, @code{dvd}, @code{dv},
317 @code{dv50}). @var{type} may be prefixed with @code{pal-}, @code{ntsc-} or
318 @code{film-} to use the corresponding standard. All the format options
319 (bitrate, codecs, buffer sizes) are then set automatically. You can just type:
322 ffmpeg -i myfile.avi -target vcd /tmp/vcd.mpg
325 Nevertheless you can specify additional options as long as you know
326 they do not conflict with the standard, as in:
329 ffmpeg -i myfile.avi -target vcd -bf 2 /tmp/vcd.mpg
332 @item -dframes @var{number} (@emph{output})
333 Set the number of data frames to record. This is an alias for @code{-frames:d}.
335 @item -frames[:@var{stream_specifier}] @var{framecount} (@emph{output,per-stream})
336 Stop writing to the stream after @var{framecount} frames.
338 @item -q[:@var{stream_specifier}] @var{q} (@emph{output,per-stream})
339 @itemx -qscale[:@var{stream_specifier}] @var{q} (@emph{output,per-stream})
340 Use fixed quality scale (VBR). The meaning of @var{q} is
343 @item -filter[:@var{stream_specifier}] @var{filter_graph} (@emph{output,per-stream})
344 @var{filter_graph} is a description of the filter graph to apply to
345 the stream. Use @code{-filters} to show all the available filters
346 (including also sources and sinks).
348 See also the @option{-filter_complex} option if you want to create filter graphs
349 with multiple inputs and/or outputs.
350 @item -pre[:@var{stream_specifier}] @var{preset_name} (@emph{output,per-stream})
351 Specify the preset for matching stream(s).
353 @item -stats (@emph{global})
354 Print encoding progress/statistics. On by default.
356 @item -progress @var{url} (@emph{global})
357 Send program-friendly progress information to @var{url}.
359 Progress information is written approximately every second and at the end of
360 the encoding process. It is made of "@var{key}=@var{value}" lines. @var{key}
361 consists of only alphanumeric characters. The last key of a sequence of
362 progress information is always "progress".
365 Enable interaction on standard input. On by default unless standard input is
366 used as an input. To explicitly disable interaction you need to specify
369 Disabling interaction on standard input is useful, for example, if
370 ffmpeg is in the background process group. Roughly the same result can
371 be achieved with @code{ffmpeg ... < /dev/null} but it requires a
374 @item -debug_ts (@emph{global})
375 Print timestamp information. It is off by default. This option is
376 mostly useful for testing and debugging purposes, and the output
377 format may change from one version to another, so it should not be
378 employed by portable scripts.
380 See also the option @code{-fdebug ts}.
382 @item -attach @var{filename} (@emph{output})
383 Add an attachment to the output file. This is supported by a few formats
384 like Matroska for e.g. fonts used in rendering subtitles. Attachments
385 are implemented as a specific type of stream, so this option will add
386 a new stream to the file. It is then possible to use per-stream options
387 on this stream in the usual way. Attachment streams created with this
388 option will be created after all the other streams (i.e. those created
389 with @code{-map} or automatic mappings).
391 Note that for Matroska you also have to set the mimetype metadata tag:
393 ffmpeg -i INPUT -attach DejaVuSans.ttf -metadata:s:2 mimetype=application/x-truetype-font out.mkv
395 (assuming that the attachment stream will be third in the output file).
397 @item -dump_attachment[:@var{stream_specifier}] @var{filename} (@emph{input,per-stream})
398 Extract the matching attachment stream into a file named @var{filename}. If
399 @var{filename} is empty, then the value of the @code{filename} metadata tag
402 E.g. to extract the first attachment to a file named 'out.ttf':
404 ffmpeg -dump_attachment:t:0 out.ttf INPUT
406 To extract all attachments to files determined by the @code{filename} tag:
408 ffmpeg -dump_attachment:t "" INPUT
411 Technical note -- attachments are implemented as codec extradata, so this
412 option can actually be used to extract extradata from any stream, not just
417 @section Video Options
420 @item -vframes @var{number} (@emph{output})
421 Set the number of video frames to record. This is an alias for @code{-frames:v}.
422 @item -r[:@var{stream_specifier}] @var{fps} (@emph{input/output,per-stream})
423 Set frame rate (Hz value, fraction or abbreviation).
425 As an input option, ignore any timestamps stored in the file and instead
426 generate timestamps assuming constant frame rate @var{fps}.
428 As an output option, duplicate or drop input frames to achieve constant output
429 frame rate @var{fps}.
431 @item -s[:@var{stream_specifier}] @var{size} (@emph{input/output,per-stream})
434 As an input option, this is a shortcut for the @option{video_size} private
435 option, recognized by some demuxers for which the frame size is either not
436 stored in the file or is configurable -- e.g. raw video or video grabbers.
438 As an output option, this inserts the @code{scale} video filter to the
439 @emph{end} of the corresponding filtergraph. Please use the @code{scale} filter
440 directly to insert it at the beginning or some other place.
442 The format is @samp{wxh} (default - same as source).
444 @item -aspect[:@var{stream_specifier}] @var{aspect} (@emph{output,per-stream})
445 Set the video display aspect ratio specified by @var{aspect}.
447 @var{aspect} can be a floating point number string, or a string of the
448 form @var{num}:@var{den}, where @var{num} and @var{den} are the
449 numerator and denominator of the aspect ratio. For example "4:3",
450 "16:9", "1.3333", and "1.7777" are valid argument values.
452 @item -croptop @var{size}
453 @item -cropbottom @var{size}
454 @item -cropleft @var{size}
455 @item -cropright @var{size}
456 All the crop options have been removed. Use -vf
457 crop=width:height:x:y instead.
459 @item -padtop @var{size}
460 @item -padbottom @var{size}
461 @item -padleft @var{size}
462 @item -padright @var{size}
463 @item -padcolor @var{hex_color}
464 All the pad options have been removed. Use -vf
465 pad=width:height:x:y:color instead.
467 @item -vn (@emph{output})
468 Disable video recording.
470 @item -vcodec @var{codec} (@emph{output})
471 Set the video codec. This is an alias for @code{-codec:v}.
473 @item -pass[:@var{stream_specifier}] @var{n} (@emph{output,per-stream})
474 Select the pass number (1 or 2). It is used to do two-pass
475 video encoding. The statistics of the video are recorded in the first
476 pass into a log file (see also the option -passlogfile),
477 and in the second pass that log file is used to generate the video
478 at the exact requested bitrate.
479 On pass 1, you may just deactivate audio and set output to null,
480 examples for Windows and Unix:
482 ffmpeg -i foo.mov -c:v libxvid -pass 1 -an -f rawvideo -y NUL
483 ffmpeg -i foo.mov -c:v libxvid -pass 1 -an -f rawvideo -y /dev/null
486 @item -passlogfile[:@var{stream_specifier}] @var{prefix} (@emph{output,per-stream})
487 Set two-pass log file name prefix to @var{prefix}, the default file name
488 prefix is ``ffmpeg2pass''. The complete file name will be
489 @file{PREFIX-N.log}, where N is a number specific to the output
492 @item -vlang @var{code}
493 Set the ISO 639 language code (3 letters) of the current video stream.
495 @item -vf @var{filter_graph} (@emph{output})
496 @var{filter_graph} is a description of the filter graph to apply to
498 Use the option "-filters" to show all the available filters (including
499 also sources and sinks). This is an alias for @code{-filter:v}.
503 @section Advanced Video Options
506 @item -pix_fmt[:@var{stream_specifier}] @var{format} (@emph{input/output,per-stream})
507 Set pixel format. Use @code{-pix_fmts} to show all the supported
509 If the selected pixel format can not be selected, ffmpeg will print a
510 warning and select the best pixel format supported by the encoder.
511 If @var{pix_fmt} is prefixed by a @code{+}, ffmpeg will exit with an error
512 if the requested pixel format can not be selected, and automatic conversions
513 inside filter graphs are disabled.
514 If @var{pix_fmt} is a single @code{+}, ffmpeg selects the same pixel format
515 as the input (or graph output) and automatic conversions are disabled.
517 @item -sws_flags @var{flags} (@emph{input/output})
522 @item -rc_override[:@var{stream_specifier}] @var{override} (@emph{output,per-stream})
523 Rate control override for specific intervals, formatted as "int,int,int"
524 list separated with slashes. Two first values are the beginning and
525 end frame numbers, last one is quantizer to use if positive, or quality
529 Deinterlace pictures.
530 This option is deprecated since the deinterlacing is very low quality.
531 Use the yadif filter with @code{-filter:v yadif}.
533 Force interlacing support in encoder (MPEG-2 and MPEG-4 only).
534 Use this option if your input file is interlaced and you want
535 to keep the interlaced format for minimum losses.
536 The alternative is to deinterlace the input stream with
537 @option{-deinterlace}, but deinterlacing introduces losses.
539 Calculate PSNR of compressed frames.
541 Dump video coding statistics to @file{vstats_HHMMSS.log}.
542 @item -vstats_file @var{file}
543 Dump video coding statistics to @var{file}.
544 @item -top[:@var{stream_specifier}] @var{n} (@emph{output,per-stream})
545 top=1/bottom=0/auto=-1 field first
546 @item -dc @var{precision}
548 @item -vtag @var{fourcc/tag} (@emph{output})
549 Force video tag/fourcc. This is an alias for @code{-tag:v}.
550 @item -qphist (@emph{global})
552 @item -vbsf @var{bitstream_filter}
554 @item -force_key_frames[:@var{stream_specifier}] @var{time}[,@var{time}...] (@emph{output,per-stream})
555 Force key frames at the specified timestamps, more precisely at the first
556 frames after each specified time.
557 This option can be useful to ensure that a seek point is present at a
558 chapter mark or any other designated place in the output file.
559 The timestamps must be specified in ascending order.
561 @item -copyinkf[:@var{stream_specifier}] (@emph{output,per-stream})
562 When doing stream copy, copy also non-key frames found at the
566 @section Audio Options
569 @item -aframes @var{number} (@emph{output})
570 Set the number of audio frames to record. This is an alias for @code{-frames:a}.
571 @item -ar[:@var{stream_specifier}] @var{freq} (@emph{input/output,per-stream})
572 Set the audio sampling frequency. For output streams it is set by
573 default to the frequency of the corresponding input stream. For input
574 streams this option only makes sense for audio grabbing devices and raw
575 demuxers and is mapped to the corresponding demuxer options.
576 @item -aq @var{q} (@emph{output})
577 Set the audio quality (codec-specific, VBR). This is an alias for -q:a.
578 @item -ac[:@var{stream_specifier}] @var{channels} (@emph{input/output,per-stream})
579 Set the number of audio channels. For output streams it is set by
580 default to the number of input audio channels. For input streams
581 this option only makes sense for audio grabbing devices and raw demuxers
582 and is mapped to the corresponding demuxer options.
583 @item -an (@emph{output})
584 Disable audio recording.
585 @item -acodec @var{codec} (@emph{input/output})
586 Set the audio codec. This is an alias for @code{-codec:a}.
587 @item -sample_fmt[:@var{stream_specifier}] @var{sample_fmt} (@emph{output,per-stream})
588 Set the audio sample format. Use @code{-sample_fmts} to get a list
589 of supported sample formats.
590 @item -af @var{filter_graph} (@emph{output})
591 @var{filter_graph} is a description of the filter graph to apply to
593 Use the option "-filters" to show all the available filters (including
594 also sources and sinks). This is an alias for @code{-filter:a}.
597 @section Advanced Audio options:
600 @item -atag @var{fourcc/tag} (@emph{output})
601 Force audio tag/fourcc. This is an alias for @code{-tag:a}.
602 @item -absf @var{bitstream_filter}
606 @section Subtitle options:
609 @item -slang @var{code}
610 Set the ISO 639 language code (3 letters) of the current subtitle stream.
611 @item -scodec @var{codec} (@emph{input/output})
612 Set the subtitle codec. This is an alias for @code{-codec:s}.
613 @item -sn (@emph{output})
614 Disable subtitle recording.
615 @item -sbsf @var{bitstream_filter}
619 @section Advanced Subtitle options:
623 @item -fix_sub_duration
624 Fix subtitles durations. For each subtitle, wait for the next packet in the
625 same stream and adjust the duration of the first to avoid overlap. This is
626 necessary with some subtitles codecs, especially DVB subtitles, because the
627 duration in the original packet is only a rough estimate and the end is
628 actually marked by an empty subtitle frame. Failing to use this option when
629 necessary can result in exaggerated durations or muxing failures due to
630 non-monotonic timestamps.
632 Note that this option will delay the output of all data until the next
633 subtitle packet is decoded: it may increase memory consumption and latency a
638 @section Advanced options
641 @item -map [-]@var{input_file_id}[:@var{stream_specifier}][,@var{sync_file_id}[:@var{stream_specifier}]] | @var{[linklabel]} (@emph{output})
643 Designate one or more input streams as a source for the output file. Each input
644 stream is identified by the input file index @var{input_file_id} and
645 the input stream index @var{input_stream_id} within the input
646 file. Both indices start at 0. If specified,
647 @var{sync_file_id}:@var{stream_specifier} sets which input stream
648 is used as a presentation sync reference.
650 The first @code{-map} option on the command line specifies the
651 source for output stream 0, the second @code{-map} option specifies
652 the source for output stream 1, etc.
654 A @code{-} character before the stream identifier creates a "negative" mapping.
655 It disables matching streams from already created mappings.
657 An alternative @var{[linklabel]} form will map outputs from complex filter
658 graphs (see the @option{-filter_complex} option) to the output file.
659 @var{linklabel} must correspond to a defined output link label in the graph.
661 For example, to map ALL streams from the first input file to output
663 ffmpeg -i INPUT -map 0 output
666 For example, if you have two audio streams in the first input file,
667 these streams are identified by "0:0" and "0:1". You can use
668 @code{-map} to select which streams to place in an output file. For
671 ffmpeg -i INPUT -map 0:1 out.wav
673 will map the input stream in @file{INPUT} identified by "0:1" to
674 the (single) output stream in @file{out.wav}.
676 For example, to select the stream with index 2 from input file
677 @file{a.mov} (specified by the identifier "0:2"), and stream with
678 index 6 from input @file{b.mov} (specified by the identifier "1:6"),
679 and copy them to the output file @file{out.mov}:
681 ffmpeg -i a.mov -i b.mov -c copy -map 0:2 -map 1:6 out.mov
684 To select all video and the third audio stream from an input file:
686 ffmpeg -i INPUT -map 0:v -map 0:a:2 OUTPUT
689 To map all the streams except the second audio, use negative mappings
691 ffmpeg -i INPUT -map 0 -map -0:a:1 OUTPUT
694 Note that using this option disables the default mappings for this output file.
696 @item -map_channel [@var{input_file_id}.@var{stream_specifier}.@var{channel_id}|-1][:@var{output_file_id}.@var{stream_specifier}]
697 Map an audio channel from a given input to an output. If
698 @var{output_file_id}.@var{stream_specifier} is not set, the audio channel will
699 be mapped on all the audio streams.
701 Using "-1" instead of
702 @var{input_file_id}.@var{stream_specifier}.@var{channel_id} will map a muted
705 For example, assuming @var{INPUT} is a stereo audio file, you can switch the
706 two audio channels with the following command:
708 ffmpeg -i INPUT -map_channel 0.0.1 -map_channel 0.0.0 OUTPUT
711 If you want to mute the first channel and keep the second:
713 ffmpeg -i INPUT -map_channel -1 -map_channel 0.0.1 OUTPUT
716 The order of the "-map_channel" option specifies the order of the channels in
717 the output stream. The output channel layout is guessed from the number of
718 channels mapped (mono if one "-map_channel", stereo if two, etc.). Using "-ac"
719 in combination of "-map_channel" makes the channel gain levels to be updated if
720 input and output channel layouts don't match (for instance two "-map_channel"
721 options and "-ac 6").
723 You can also extract each channel of an input to specific outputs; the following
724 command extracts two channels of the @var{INPUT} audio stream (file 0, stream 0)
725 to the respective @var{OUTPUT_CH0} and @var{OUTPUT_CH1} outputs:
727 ffmpeg -i INPUT -map_channel 0.0.0 OUTPUT_CH0 -map_channel 0.0.1 OUTPUT_CH1
730 The following example splits the channels of a stereo input into two separate
731 streams, which are put into the same output file:
733 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
736 Note that currently each output stream can only contain channels from a single
737 input stream; you can't for example use "-map_channel" to pick multiple input
738 audio channels contained in different streams (from the same or different files)
739 and merge them into a single output stream. It is therefore not currently
740 possible, for example, to turn two separate mono streams into a single stereo
741 stream. However splitting a stereo stream into two single channel mono streams
744 If you need this feature, a possible workaround is to use the @emph{amerge}
745 filter. For example, if you need to merge a media (here @file{input.mkv}) with 2
746 mono audio streams into one single stereo channel audio stream (and keep the
747 video stream), you can use the following command:
749 ffmpeg -i input.mkv -filter_complex "[0:1] [0:2] amerge" -c:a pcm_s16le -c:v copy output.mkv
752 @item -map_metadata[:@var{metadata_spec_out}] @var{infile}[:@var{metadata_spec_in}] (@emph{output,per-metadata})
753 Set metadata information of the next output file from @var{infile}. Note that
754 those are file indices (zero-based), not filenames.
755 Optional @var{metadata_spec_in/out} parameters specify, which metadata to copy.
756 A metadata specifier can have the following forms:
759 global metadata, i.e. metadata that applies to the whole file
761 @item @var{s}[:@var{stream_spec}]
762 per-stream metadata. @var{stream_spec} is a stream specifier as described
763 in the @ref{Stream specifiers} chapter. In an input metadata specifier, the first
764 matching stream is copied from. In an output metadata specifier, all matching
765 streams are copied to.
767 @item @var{c}:@var{chapter_index}
768 per-chapter metadata. @var{chapter_index} is the zero-based chapter index.
770 @item @var{p}:@var{program_index}
771 per-program metadata. @var{program_index} is the zero-based program index.
773 If metadata specifier is omitted, it defaults to global.
775 By default, global metadata is copied from the first input file,
776 per-stream and per-chapter metadata is copied along with streams/chapters. These
777 default mappings are disabled by creating any mapping of the relevant type. A negative
778 file index can be used to create a dummy mapping that just disables automatic copying.
780 For example to copy metadata from the first stream of the input file to global metadata
783 ffmpeg -i in.ogg -map_metadata 0:s:0 out.mp3
786 To do the reverse, i.e. copy global metadata to all audio streams:
788 ffmpeg -i in.mkv -map_metadata:s:a 0:g out.mkv
790 Note that simple @code{0} would work as well in this example, since global
791 metadata is assumed by default.
793 @item -map_chapters @var{input_file_index} (@emph{output})
794 Copy chapters from input file with index @var{input_file_index} to the next
795 output file. If no chapter mapping is specified, then chapters are copied from
796 the first input file with at least one chapter. Use a negative file index to
797 disable any chapter copying.
799 @item -benchmark (@emph{global})
800 Show benchmarking information at the end of an encode.
801 Shows CPU time used and maximum memory consumption.
802 Maximum memory consumption is not supported on all systems,
803 it will usually display as 0 if not supported.
804 @item -benchmark_all (@emph{global})
805 Show benchmarking information during the encode.
806 Shows CPU time used in various steps (audio/video encode/decode).
807 @item -timelimit @var{duration} (@emph{global})
808 Exit after ffmpeg has been running for @var{duration} seconds.
809 @item -dump (@emph{global})
810 Dump each input packet to stderr.
811 @item -hex (@emph{global})
812 When dumping packets, also dump the payload.
813 @item -re (@emph{input})
814 Read input at native frame rate. Mainly used to simulate a grab device.
815 By default @command{ffmpeg} attempts to read the input(s) as fast as possible.
816 This option will slow down the reading of the input(s) to the native frame rate
817 of the input(s). It is useful for real-time output (e.g. live streaming). If
818 your input(s) is coming from some other live streaming source (through HTTP or
819 UDP for example) the server might already be in real-time, thus the option will
820 likely not be required. On the other hand, this is meaningful if your input(s)
821 is a file you are trying to push in real-time.
823 Loop over the input stream. Currently it works only for image
824 streams. This option is used for automatic FFserver testing.
825 This option is deprecated, use -loop 1.
826 @item -loop_output @var{number_of_times}
827 Repeatedly loop output for formats that support looping such as animated GIF
828 (0 will loop the output infinitely).
829 This option is deprecated, use -loop.
830 @item -vsync @var{parameter}
832 For compatibility reasons old values can be specified as numbers.
833 Newly added values will have to be specified as strings always.
837 Each frame is passed with its timestamp from the demuxer to the muxer.
839 Frames will be duplicated and dropped to achieve exactly the requested
842 Frames are passed through with their timestamp or dropped so as to
843 prevent 2 frames from having the same timestamp.
845 As passthrough but destroys all timestamps, making the muxer generate
846 fresh timestamps based on frame-rate.
848 Chooses between 1 and 2 depending on muxer capabilities. This is the
852 With -map you can select from which stream the timestamps should be
853 taken. You can leave either video or audio unchanged and sync the
854 remaining stream(s) to the unchanged one.
856 @item -async @var{samples_per_second}
857 Audio sync method. "Stretches/squeezes" the audio stream to match the timestamps,
858 the parameter is the maximum samples per second by which the audio is changed.
859 -async 1 is a special case where only the start of the audio stream is corrected
860 without any later correction.
861 This option has been deprecated. Use the @code{aresample} audio filter instead.
864 Do not process input timestamps, but keep their values without trying
865 to sanitize them. In particular, do not remove the initial start time
868 Note that, depending on the @option{vsync} option or on specific muxer
869 processing, the output timestamps may mismatch with the input
870 timestamps even when this option is selected.
872 @item -copytb @var{mode}
873 Specify how to set the encoder timebase when stream copying. @var{mode} is an
874 integer numeric value, and can assume one of the following values:
878 Use the demuxer timebase.
880 The time base is copied to the output encoder from the corresponding input
881 demuxer. This is sometimes required to avoid non monotonically increasing
882 timestamps when copying video streams with variable frame rate.
885 Use the decoder timebase.
887 The time base is copied to the output encoder from the corresponding input
891 Try to make the choice automatically, in order to generate a sane output.
896 @item -shortest (@emph{output})
897 Finish encoding when the shortest input stream ends.
898 @item -dts_delta_threshold
899 Timestamp discontinuity delta threshold.
900 @item -muxdelay @var{seconds} (@emph{input})
901 Set the maximum demux-decode delay.
902 @item -muxpreload @var{seconds} (@emph{input})
903 Set the initial demux-decode delay.
904 @item -streamid @var{output-stream-index}:@var{new-value} (@emph{output})
905 Assign a new stream-id value to an output stream. This option should be
906 specified prior to the output filename to which it applies.
907 For the situation where multiple output files exist, a streamid
908 may be reassigned to a different value.
910 For example, to set the stream 0 PID to 33 and the stream 1 PID to 36 for
911 an output mpegts file:
913 ffmpeg -i infile -streamid 0:33 -streamid 1:36 out.ts
916 @item -bsf[:@var{stream_specifier}] @var{bitstream_filters} (@emph{output,per-stream})
917 Set bitstream filters for matching streams. @var{bistream_filters} is
918 a comma-separated list of bitstream filters. Use the @code{-bsfs} option
919 to get the list of bitstream filters.
921 ffmpeg -i h264.mp4 -c:v copy -bsf:v h264_mp4toannexb -an out.h264
924 ffmpeg -i file.mov -an -vn -bsf:s mov2textsub -c:s copy -f rawvideo sub.txt
927 @item -tag[:@var{stream_specifier}] @var{codec_tag} (@emph{per-stream})
928 Force a tag/fourcc for matching streams.
930 @item -timecode @var{hh}:@var{mm}:@var{ss}SEP@var{ff}
931 Specify Timecode for writing. @var{SEP} is ':' for non drop timecode and ';'
934 ffmpeg -i input.mpg -timecode 01:02:03.04 -r 30000/1001 -s ntsc output.mpg
937 @item -filter_complex @var{filtergraph} (@emph{global})
938 Define a complex filter graph, i.e. one with arbitrary number of inputs and/or
939 outputs. For simple graphs -- those with one input and one output of the same
940 type -- see the @option{-filter} options. @var{filtergraph} is a description of
941 the filter graph, as described in @ref{Filtergraph syntax}.
943 Input link labels must refer to input streams using the
944 @code{[file_index:stream_specifier]} syntax (i.e. the same as @option{-map}
945 uses). If @var{stream_specifier} matches multiple streams, the first one will be
946 used. An unlabeled input will be connected to the first unused input stream of
949 Output link labels are referred to with @option{-map}. Unlabeled outputs are
950 added to the first output file.
952 Note that with this option it is possible to use only lavfi sources without
955 For example, to overlay an image over video
957 ffmpeg -i video.mkv -i image.png -filter_complex '[0:v][1:v]overlay[out]' -map
960 Here @code{[0:v]} refers to the first video stream in the first input file,
961 which is linked to the first (main) input of the overlay filter. Similarly the
962 first video stream in the second input is linked to the second (overlay) input
965 Assuming there is only one video stream in each input file, we can omit input
966 labels, so the above is equivalent to
968 ffmpeg -i video.mkv -i image.png -filter_complex 'overlay[out]' -map
972 Furthermore we can omit the output label and the single output from the filter
973 graph will be added to the output file automatically, so we can simply write
975 ffmpeg -i video.mkv -i image.png -filter_complex 'overlay' out.mkv
978 To generate 5 seconds of pure red video using lavfi @code{color} source:
980 ffmpeg -filter_complex 'color=red' -t 5 out.mkv
984 As a special exception, you can use a bitmap subtitle stream as input: it
985 will be converted into a video with the same size as the largest video in
986 the file, or 720×576 if no video is present. Note that this is an
987 experimental and temporary solution. It will be removed once libavfilter has
988 proper support for subtitles.
990 For example, to hardcode subtitles on top of a DVB-T recording stored in
991 MPEG-TS format, delaying the subtitles by 1 second:
993 ffmpeg -i input.ts -filter_complex \
994 '[#0x2ef] setpts=PTS+1/TB [sub] ; [#0x2d0] [sub] overlay' \
995 -sn -map '#0x2dc' output.mkv
997 (0x2d0, 0x2dc and 0x2ef are the MPEG-TS PIDs of respectively the video,
998 audio and subtitles streams; 0:0, 0:3 and 0:7 would have worked too)
1000 @section Preset files
1001 A preset file contains a sequence of @var{option}=@var{value} pairs,
1002 one for each line, specifying a sequence of options which would be
1003 awkward to specify on the command line. Lines starting with the hash
1004 ('#') character are ignored and are used to provide comments. Check
1005 the @file{presets} directory in the FFmpeg source tree for examples.
1007 Preset files are specified with the @code{vpre}, @code{apre},
1008 @code{spre}, and @code{fpre} options. The @code{fpre} option takes the
1009 filename of the preset instead of a preset name as input and can be
1010 used for any kind of codec. For the @code{vpre}, @code{apre}, and
1011 @code{spre} options, the options specified in a preset file are
1012 applied to the currently selected codec of the same type as the preset
1015 The argument passed to the @code{vpre}, @code{apre}, and @code{spre}
1016 preset options identifies the preset file to use according to the
1019 First ffmpeg searches for a file named @var{arg}.ffpreset in the
1020 directories @file{$FFMPEG_DATADIR} (if set), and @file{$HOME/.ffmpeg}, and in
1021 the datadir defined at configuration time (usually @file{PREFIX/share/ffmpeg})
1022 or in a @file{ffpresets} folder along the executable on win32,
1023 in that order. For example, if the argument is @code{libvpx-1080p}, it will
1024 search for the file @file{libvpx-1080p.ffpreset}.
1026 If no such file is found, then ffmpeg will search for a file named
1027 @var{codec_name}-@var{arg}.ffpreset in the above-mentioned
1028 directories, where @var{codec_name} is the name of the codec to which
1029 the preset file options will be applied. For example, if you select
1030 the video codec with @code{-vcodec libvpx} and use @code{-vpre 1080p},
1031 then it will search for the file @file{libvpx-1080p.ffpreset}.
1039 For streaming at very low bitrate application, use a low frame rate
1040 and a small GOP size. This is especially true for RealVideo where
1041 the Linux player does not seem to be very fast, so it can miss
1042 frames. An example is:
1045 ffmpeg -g 3 -r 3 -t 10 -b:v 50k -s qcif -f rv10 /tmp/b.rm
1049 The parameter 'q' which is displayed while encoding is the current
1050 quantizer. The value 1 indicates that a very good quality could
1051 be achieved. The value 31 indicates the worst quality. If q=31 appears
1052 too often, it means that the encoder cannot compress enough to meet
1053 your bitrate. You must either increase the bitrate, decrease the
1054 frame rate or decrease the frame size.
1057 If your computer is not fast enough, you can speed up the
1058 compression at the expense of the compression ratio. You can use
1059 '-me zero' to speed up motion estimation, and '-g 0' to disable
1060 motion estimation completely (you have only I-frames, which means it
1061 is about as good as JPEG compression).
1064 To have very low audio bitrates, reduce the sampling frequency
1065 (down to 22050 Hz for MPEG audio, 22050 or 11025 for AC-3).
1068 To have a constant quality (but a variable bitrate), use the option
1069 '-qscale n' when 'n' is between 1 (excellent quality) and 31 (worst
1076 @c man begin EXAMPLES
1078 @section Preset files
1080 A preset file contains a sequence of @var{option=value} pairs, one for
1081 each line, specifying a sequence of options which can be specified also on
1082 the command line. Lines starting with the hash ('#') character are ignored and
1083 are used to provide comments. Empty lines are also ignored. Check the
1084 @file{presets} directory in the FFmpeg source tree for examples.
1086 Preset files are specified with the @code{pre} option, this option takes a
1087 preset name as input. FFmpeg searches for a file named @var{preset_name}.avpreset in
1088 the directories @file{$AVCONV_DATADIR} (if set), and @file{$HOME/.ffmpeg}, and in
1089 the data directory defined at configuration time (usually @file{$PREFIX/share/ffmpeg})
1090 in that order. For example, if the argument is @code{libx264-max}, it will
1091 search for the file @file{libx264-max.avpreset}.
1093 @section Video and Audio grabbing
1095 If you specify the input format and device then ffmpeg can grab video
1099 ffmpeg -f oss -i /dev/dsp -f video4linux2 -i /dev/video0 /tmp/out.mpg
1102 Or with an ALSA audio source (mono input, card id 1) instead of OSS:
1104 ffmpeg -f alsa -ac 1 -i hw:1 -f video4linux2 -i /dev/video0 /tmp/out.mpg
1107 Note that you must activate the right video source and channel before
1108 launching ffmpeg with any TV viewer such as
1109 @uref{http://linux.bytesex.org/xawtv/, xawtv} by Gerd Knorr. You also
1110 have to set the audio recording levels correctly with a
1113 @section X11 grabbing
1115 Grab the X11 display with ffmpeg via
1118 ffmpeg -f x11grab -s cif -r 25 -i :0.0 /tmp/out.mpg
1121 0.0 is display.screen number of your X11 server, same as
1122 the DISPLAY environment variable.
1125 ffmpeg -f x11grab -s cif -r 25 -i :0.0+10,20 /tmp/out.mpg
1128 0.0 is display.screen number of your X11 server, same as the DISPLAY environment
1129 variable. 10 is the x-offset and 20 the y-offset for the grabbing.
1131 @section Video and Audio file format conversion
1133 Any supported file format and protocol can serve as input to ffmpeg:
1138 You can use YUV files as input:
1141 ffmpeg -i /tmp/test%d.Y /tmp/out.mpg
1144 It will use the files:
1146 /tmp/test0.Y, /tmp/test0.U, /tmp/test0.V,
1147 /tmp/test1.Y, /tmp/test1.U, /tmp/test1.V, etc...
1150 The Y files use twice the resolution of the U and V files. They are
1151 raw files, without header. They can be generated by all decent video
1152 decoders. You must specify the size of the image with the @option{-s} option
1153 if ffmpeg cannot guess it.
1156 You can input from a raw YUV420P file:
1159 ffmpeg -i /tmp/test.yuv /tmp/out.avi
1162 test.yuv is a file containing raw YUV planar data. Each frame is composed
1163 of the Y plane followed by the U and V planes at half vertical and
1164 horizontal resolution.
1167 You can output to a raw YUV420P file:
1170 ffmpeg -i mydivx.avi hugefile.yuv
1174 You can set several input files and output files:
1177 ffmpeg -i /tmp/a.wav -s 640x480 -i /tmp/a.yuv /tmp/a.mpg
1180 Converts the audio file a.wav and the raw YUV video file a.yuv
1184 You can also do audio and video conversions at the same time:
1187 ffmpeg -i /tmp/a.wav -ar 22050 /tmp/a.mp2
1190 Converts a.wav to MPEG audio at 22050 Hz sample rate.
1193 You can encode to several formats at the same time and define a
1194 mapping from input stream to output streams:
1197 ffmpeg -i /tmp/a.wav -map 0:a -b:a 64k /tmp/a.mp2 -map 0:a -b:a 128k /tmp/b.mp2
1200 Converts a.wav to a.mp2 at 64 kbits and to b.mp2 at 128 kbits. '-map
1201 file:index' specifies which input stream is used for each output
1202 stream, in the order of the definition of output streams.
1205 You can transcode decrypted VOBs:
1208 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
1211 This is a typical DVD ripping example; the input is a VOB file, the
1212 output an AVI file with MPEG-4 video and MP3 audio. Note that in this
1213 command we use B-frames so the MPEG-4 stream is DivX5 compatible, and
1214 GOP size is 300 which means one intra frame every 10 seconds for 29.97fps
1215 input video. Furthermore, the audio stream is MP3-encoded so you need
1216 to enable LAME support by passing @code{--enable-libmp3lame} to configure.
1217 The mapping is particularly useful for DVD transcoding
1218 to get the desired audio language.
1220 NOTE: To see the supported input formats, use @code{ffmpeg -formats}.
1223 You can extract images from a video, or create a video from many images:
1225 For extracting images from a video:
1227 ffmpeg -i foo.avi -r 1 -s WxH -f image2 foo-%03d.jpeg
1230 This will extract one video frame per second from the video and will
1231 output them in files named @file{foo-001.jpeg}, @file{foo-002.jpeg},
1232 etc. Images will be rescaled to fit the new WxH values.
1234 If you want to extract just a limited number of frames, you can use the
1235 above command in combination with the -vframes or -t option, or in
1236 combination with -ss to start extracting from a certain point in time.
1238 For creating a video from many images:
1240 ffmpeg -f image2 -i foo-%03d.jpeg -r 12 -s WxH foo.avi
1243 The syntax @code{foo-%03d.jpeg} specifies to use a decimal number
1244 composed of three digits padded with zeroes to express the sequence
1245 number. It is the same syntax supported by the C printf function, but
1246 only formats accepting a normal integer are suitable.
1248 When importing an image sequence, -i also supports expanding
1249 shell-like wildcard patterns (globbing) internally, by selecting the
1250 image2-specific @code{-pattern_type glob} option.
1252 For example, for creating a video from filenames matching the glob pattern
1255 ffmpeg -f image2 -pattern_type glob -i 'foo-*.jpeg' -r 12 -s WxH foo.avi
1259 You can put many streams of the same type in the output:
1262 ffmpeg -i test1.avi -i test2.avi -map 0:3 -map 0:2 -map 0:1 -map 0:0 -c copy test12.nut
1265 The resulting output file @file{test12.avi} will contain first four streams from
1266 the input file in reverse order.
1269 To force CBR video output:
1271 ffmpeg -i myfile.avi -b 4000k -minrate 4000k -maxrate 4000k -bufsize 1835k out.m2v
1275 The four options lmin, lmax, mblmin and mblmax use 'lambda' units,
1276 but you may use the QP2LAMBDA constant to easily convert from 'q' units:
1278 ffmpeg -i src.ext -lmax 21*QP2LAMBDA dst.ext
1284 @include syntax.texi
1286 @include decoders.texi
1287 @include encoders.texi
1288 @include demuxers.texi
1289 @include muxers.texi
1290 @include indevs.texi
1291 @include outdevs.texi
1292 @include protocols.texi
1293 @include bitstream_filters.texi
1294 @include filters.texi
1295 @include metadata.texi
1300 @settitle ffmpeg video converter
1302 @c man begin SEEALSO
1303 ffplay(1), ffprobe(1), ffserver(1) and the FFmpeg HTML documentation
1306 @c man begin AUTHORS