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 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
368 Useful, for example, if ffmpeg is in the background process group. Roughly
369 the same result can be achieved with @code{ffmpeg ... < /dev/null} but it
372 @item -debug_ts (@emph{global})
373 Print timestamp information. It is off by default. This option is
374 mostly useful for testing and debugging purposes, and the output
375 format may change from one version to another, so it should not be
376 employed by portable scripts.
378 See also the option @code{-fdebug ts}.
380 @item -attach @var{filename} (@emph{output})
381 Add an attachment to the output file. This is supported by a few formats
382 like Matroska for e.g. fonts used in rendering subtitles. Attachments
383 are implemented as a specific type of stream, so this option will add
384 a new stream to the file. It is then possible to use per-stream options
385 on this stream in the usual way. Attachment streams created with this
386 option will be created after all the other streams (i.e. those created
387 with @code{-map} or automatic mappings).
389 Note that for Matroska you also have to set the mimetype metadata tag:
391 ffmpeg -i INPUT -attach DejaVuSans.ttf -metadata:s:2 mimetype=application/x-truetype-font out.mkv
393 (assuming that the attachment stream will be third in the output file).
395 @item -dump_attachment[:@var{stream_specifier}] @var{filename} (@emph{input,per-stream})
396 Extract the matching attachment stream into a file named @var{filename}. If
397 @var{filename} is empty, then the value of the @code{filename} metadata tag
400 E.g. to extract the first attachment to a file named 'out.ttf':
402 ffmpeg -dump_attachment:t:0 out.ttf INPUT
404 To extract all attachments to files determined by the @code{filename} tag:
406 ffmpeg -dump_attachment:t "" INPUT
409 Technical note -- attachments are implemented as codec extradata, so this
410 option can actually be used to extract extradata from any stream, not just
415 @section Video Options
418 @item -vframes @var{number} (@emph{output})
419 Set the number of video frames to record. This is an alias for @code{-frames:v}.
420 @item -r[:@var{stream_specifier}] @var{fps} (@emph{input/output,per-stream})
421 Set frame rate (Hz value, fraction or abbreviation).
423 As an input option, ignore any timestamps stored in the file and instead
424 generate timestamps assuming constant frame rate @var{fps}.
426 As an output option, duplicate or drop input frames to achieve constant output
427 frame rate @var{fps} (note that this actually causes the @code{fps} filter to be
428 inserted to the end of the corresponding filtergraph).
430 @item -s[:@var{stream_specifier}] @var{size} (@emph{input/output,per-stream})
433 As an input option, this is a shortcut for the @option{video_size} private
434 option, recognized by some demuxers for which the frame size is either not
435 stored in the file or is configurable -- e.g. raw video or video grabbers.
437 As an output option, this inserts the @code{scale} video filter to the
438 @emph{end} of the corresponding filtergraph. Please use the @code{scale} filter
439 directly to insert it at the beginning or some other place.
441 The format is @samp{wxh} (default - same as source).
443 @item -aspect[:@var{stream_specifier}] @var{aspect} (@emph{output,per-stream})
444 Set the video display aspect ratio specified by @var{aspect}.
446 @var{aspect} can be a floating point number string, or a string of the
447 form @var{num}:@var{den}, where @var{num} and @var{den} are the
448 numerator and denominator of the aspect ratio. For example "4:3",
449 "16:9", "1.3333", and "1.7777" are valid argument values.
451 @item -croptop @var{size}
452 @item -cropbottom @var{size}
453 @item -cropleft @var{size}
454 @item -cropright @var{size}
455 All the crop options have been removed. Use -vf
456 crop=width:height:x:y instead.
458 @item -padtop @var{size}
459 @item -padbottom @var{size}
460 @item -padleft @var{size}
461 @item -padright @var{size}
462 @item -padcolor @var{hex_color}
463 All the pad options have been removed. Use -vf
464 pad=width:height:x:y:color instead.
466 @item -vn (@emph{output})
467 Disable video recording.
469 @item -vcodec @var{codec} (@emph{output})
470 Set the video codec. This is an alias for @code{-codec:v}.
472 Use same quantizer as source (implies VBR).
474 Note that this is NOT SAME QUALITY. Do not use this option unless you know you
478 Select the pass number (1 or 2). It is used to do two-pass
479 video encoding. The statistics of the video are recorded in the first
480 pass into a log file (see also the option -passlogfile),
481 and in the second pass that log file is used to generate the video
482 at the exact requested bitrate.
483 On pass 1, you may just deactivate audio and set output to null,
484 examples for Windows and Unix:
486 ffmpeg -i foo.mov -c:v libxvid -pass 1 -an -f rawvideo -y NUL
487 ffmpeg -i foo.mov -c:v libxvid -pass 1 -an -f rawvideo -y /dev/null
490 @item -passlogfile @var{prefix} (@emph{global})
491 Set two-pass log file name prefix to @var{prefix}, the default file name
492 prefix is ``ffmpeg2pass''. The complete file name will be
493 @file{PREFIX-N.log}, where N is a number specific to the output
496 @item -vlang @var{code}
497 Set the ISO 639 language code (3 letters) of the current video stream.
499 @item -vf @var{filter_graph} (@emph{output})
500 @var{filter_graph} is a description of the filter graph to apply to
502 Use the option "-filters" to show all the available filters (including
503 also sources and sinks). This is an alias for @code{-filter:v}.
507 @section Advanced Video Options
510 @item -pix_fmt[:@var{stream_specifier}] @var{format} (@emph{input/output,per-stream})
511 Set pixel format. Use @code{-pix_fmts} to show all the supported
513 If the selected pixel format can not be selected, ffmpeg will print a
514 warning and select the best pixel format supported by the encoder.
515 If @var{pix_fmt} is prefixed by a @code{+}, ffmpeg will exit with an error
516 if the requested pixel format can not be selected, and automatic conversions
517 inside filter graphs are disabled.
518 If @var{pix_fmt} is a single @code{+}, ffmpeg selects the same pixel format
519 as the input (or graph output) and automatic conversions are disabled.
521 @item -sws_flags @var{flags} (@emph{input/output})
526 @item -rc_override[:@var{stream_specifier}] @var{override} (@emph{output,per-stream})
527 Rate control override for specific intervals, formatted as "int,int,int"
528 list separated with slashes. Two first values are the beginning and
529 end frame numbers, last one is quantizer to use if positive, or quality
533 Deinterlace pictures.
534 This option is deprecated since the deinterlacing is very low quality.
535 Use the yadif filter with @code{-filter:v yadif}.
537 Force interlacing support in encoder (MPEG-2 and MPEG-4 only).
538 Use this option if your input file is interlaced and you want
539 to keep the interlaced format for minimum losses.
540 The alternative is to deinterlace the input stream with
541 @option{-deinterlace}, but deinterlacing introduces losses.
543 Calculate PSNR of compressed frames.
545 Dump video coding statistics to @file{vstats_HHMMSS.log}.
546 @item -vstats_file @var{file}
547 Dump video coding statistics to @var{file}.
548 @item -top[:@var{stream_specifier}] @var{n} (@emph{output,per-stream})
549 top=1/bottom=0/auto=-1 field first
550 @item -dc @var{precision}
552 @item -vtag @var{fourcc/tag} (@emph{output})
553 Force video tag/fourcc. This is an alias for @code{-tag:v}.
554 @item -qphist (@emph{global})
556 @item -vbsf @var{bitstream_filter}
558 @item -force_key_frames[:@var{stream_specifier}] @var{time}[,@var{time}...] (@emph{output,per-stream})
559 Force key frames at the specified timestamps, more precisely at the first
560 frames after each specified time.
561 This option can be useful to ensure that a seek point is present at a
562 chapter mark or any other designated place in the output file.
563 The timestamps must be specified in ascending order.
565 @item -copyinkf[:@var{stream_specifier}] (@emph{output,per-stream})
566 When doing stream copy, copy also non-key frames found at the
570 @section Audio Options
573 @item -aframes @var{number} (@emph{output})
574 Set the number of audio frames to record. This is an alias for @code{-frames:a}.
575 @item -ar[:@var{stream_specifier}] @var{freq} (@emph{input/output,per-stream})
576 Set the audio sampling frequency. For output streams it is set by
577 default to the frequency of the corresponding input stream. For input
578 streams this option only makes sense for audio grabbing devices and raw
579 demuxers and is mapped to the corresponding demuxer options.
580 @item -aq @var{q} (@emph{output})
581 Set the audio quality (codec-specific, VBR). This is an alias for -q:a.
582 @item -ac[:@var{stream_specifier}] @var{channels} (@emph{input/output,per-stream})
583 Set the number of audio channels. For output streams it is set by
584 default to the number of input audio channels. For input streams
585 this option only makes sense for audio grabbing devices and raw demuxers
586 and is mapped to the corresponding demuxer options.
587 @item -an (@emph{output})
588 Disable audio recording.
589 @item -acodec @var{codec} (@emph{input/output})
590 Set the audio codec. This is an alias for @code{-codec:a}.
591 @item -sample_fmt[:@var{stream_specifier}] @var{sample_fmt} (@emph{output,per-stream})
592 Set the audio sample format. Use @code{-sample_fmts} to get a list
593 of supported sample formats.
594 @item -af @var{filter_graph} (@emph{output})
595 @var{filter_graph} is a description of the filter graph to apply to
597 Use the option "-filters" to show all the available filters (including
598 also sources and sinks). This is an alias for @code{-filter:a}.
601 @section Advanced Audio options:
604 @item -atag @var{fourcc/tag} (@emph{output})
605 Force audio tag/fourcc. This is an alias for @code{-tag:a}.
606 @item -absf @var{bitstream_filter}
610 @section Subtitle options:
613 @item -slang @var{code}
614 Set the ISO 639 language code (3 letters) of the current subtitle stream.
615 @item -scodec @var{codec} (@emph{input/output})
616 Set the subtitle codec. This is an alias for @code{-codec:s}.
617 @item -sn (@emph{output})
618 Disable subtitle recording.
619 @item -sbsf @var{bitstream_filter}
623 @section Advanced Subtitle options:
627 @item -fix_sub_duration
628 Fix subtitles durations. For each subtitle, wait for the next packet in the
629 same stream and adjust the duration of the first to avoid overlap. This is
630 necessary with some subtitles codecs, especially DVB subtitles, because the
631 duration in the original packet is only a rough estimate and the end is
632 actually marked by an empty subtitle frame. Failing to use this option when
633 necessary can result in exaggerated durations or muxing failures due to
634 non-monotonic timestamps.
636 Note that this option will delay the output of all data until the next
637 subtitle packet is decoded: it may increase memory consumption and latency a
642 @section Audio/Video grab options
645 @item -isync (@emph{global})
646 Synchronize read on input.
649 @section Advanced options
652 @item -map [-]@var{input_file_id}[:@var{stream_specifier}][,@var{sync_file_id}[:@var{stream_specifier}]] | @var{[linklabel]} (@emph{output})
654 Designate one or more input streams as a source for the output file. Each input
655 stream is identified by the input file index @var{input_file_id} and
656 the input stream index @var{input_stream_id} within the input
657 file. Both indices start at 0. If specified,
658 @var{sync_file_id}:@var{stream_specifier} sets which input stream
659 is used as a presentation sync reference.
661 The first @code{-map} option on the command line specifies the
662 source for output stream 0, the second @code{-map} option specifies
663 the source for output stream 1, etc.
665 A @code{-} character before the stream identifier creates a "negative" mapping.
666 It disables matching streams from already created mappings.
668 An alternative @var{[linklabel]} form will map outputs from complex filter
669 graphs (see the @option{-filter_complex} option) to the output file.
670 @var{linklabel} must correspond to a defined output link label in the graph.
672 For example, to map ALL streams from the first input file to output
674 ffmpeg -i INPUT -map 0 output
677 For example, if you have two audio streams in the first input file,
678 these streams are identified by "0:0" and "0:1". You can use
679 @code{-map} to select which streams to place in an output file. For
682 ffmpeg -i INPUT -map 0:1 out.wav
684 will map the input stream in @file{INPUT} identified by "0:1" to
685 the (single) output stream in @file{out.wav}.
687 For example, to select the stream with index 2 from input file
688 @file{a.mov} (specified by the identifier "0:2"), and stream with
689 index 6 from input @file{b.mov} (specified by the identifier "1:6"),
690 and copy them to the output file @file{out.mov}:
692 ffmpeg -i a.mov -i b.mov -c copy -map 0:2 -map 1:6 out.mov
695 To select all video and the third audio stream from an input file:
697 ffmpeg -i INPUT -map 0:v -map 0:a:2 OUTPUT
700 To map all the streams except the second audio, use negative mappings
702 ffmpeg -i INPUT -map 0 -map -0:a:1 OUTPUT
705 Note that using this option disables the default mappings for this output file.
707 @item -map_channel [@var{input_file_id}.@var{stream_specifier}.@var{channel_id}|-1][:@var{output_file_id}.@var{stream_specifier}]
708 Map an audio channel from a given input to an output. If
709 @var{output_file_id}.@var{stream_specifier} is not set, the audio channel will
710 be mapped on all the audio streams.
712 Using "-1" instead of
713 @var{input_file_id}.@var{stream_specifier}.@var{channel_id} will map a muted
716 For example, assuming @var{INPUT} is a stereo audio file, you can switch the
717 two audio channels with the following command:
719 ffmpeg -i INPUT -map_channel 0.0.1 -map_channel 0.0.0 OUTPUT
722 If you want to mute the first channel and keep the second:
724 ffmpeg -i INPUT -map_channel -1 -map_channel 0.0.1 OUTPUT
727 The order of the "-map_channel" option specifies the order of the channels in
728 the output stream. The output channel layout is guessed from the number of
729 channels mapped (mono if one "-map_channel", stereo if two, etc.). Using "-ac"
730 in combination of "-map_channel" makes the channel gain levels to be updated if
731 input and output channel layouts don't match (for instance two "-map_channel"
732 options and "-ac 6").
734 You can also extract each channel of an input to specific outputs; the following
735 command extracts two channels of the @var{INPUT} audio stream (file 0, stream 0)
736 to the respective @var{OUTPUT_CH0} and @var{OUTPUT_CH1} outputs:
738 ffmpeg -i INPUT -map_channel 0.0.0 OUTPUT_CH0 -map_channel 0.0.1 OUTPUT_CH1
741 The following example splits the channels of a stereo input into two separate
742 streams, which are put into the same output file:
744 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
747 Note that currently each output stream can only contain channels from a single
748 input stream; you can't for example use "-map_channel" to pick multiple input
749 audio channels contained in different streams (from the same or different files)
750 and merge them into a single output stream. It is therefore not currently
751 possible, for example, to turn two separate mono streams into a single stereo
752 stream. However splitting a stereo stream into two single channel mono streams
755 If you need this feature, a possible workaround is to use the @emph{amerge}
756 filter. For example, if you need to merge a media (here @file{input.mkv}) with 2
757 mono audio streams into one single stereo channel audio stream (and keep the
758 video stream), you can use the following command:
760 ffmpeg -i input.mkv -filter_complex "[0:1] [0:2] amerge" -c:a pcm_s16le -c:v copy output.mkv
763 @item -map_metadata[:@var{metadata_spec_out}] @var{infile}[:@var{metadata_spec_in}] (@emph{output,per-metadata})
764 Set metadata information of the next output file from @var{infile}. Note that
765 those are file indices (zero-based), not filenames.
766 Optional @var{metadata_spec_in/out} parameters specify, which metadata to copy.
767 A metadata specifier can have the following forms:
770 global metadata, i.e. metadata that applies to the whole file
772 @item @var{s}[:@var{stream_spec}]
773 per-stream metadata. @var{stream_spec} is a stream specifier as described
774 in the @ref{Stream specifiers} chapter. In an input metadata specifier, the first
775 matching stream is copied from. In an output metadata specifier, all matching
776 streams are copied to.
778 @item @var{c}:@var{chapter_index}
779 per-chapter metadata. @var{chapter_index} is the zero-based chapter index.
781 @item @var{p}:@var{program_index}
782 per-program metadata. @var{program_index} is the zero-based program index.
784 If metadata specifier is omitted, it defaults to global.
786 By default, global metadata is copied from the first input file,
787 per-stream and per-chapter metadata is copied along with streams/chapters. These
788 default mappings are disabled by creating any mapping of the relevant type. A negative
789 file index can be used to create a dummy mapping that just disables automatic copying.
791 For example to copy metadata from the first stream of the input file to global metadata
794 ffmpeg -i in.ogg -map_metadata 0:s:0 out.mp3
797 To do the reverse, i.e. copy global metadata to all audio streams:
799 ffmpeg -i in.mkv -map_metadata:s:a 0:g out.mkv
801 Note that simple @code{0} would work as well in this example, since global
802 metadata is assumed by default.
804 @item -map_chapters @var{input_file_index} (@emph{output})
805 Copy chapters from input file with index @var{input_file_index} to the next
806 output file. If no chapter mapping is specified, then chapters are copied from
807 the first input file with at least one chapter. Use a negative file index to
808 disable any chapter copying.
809 @item -debug @var{category}
810 Print specific debug info.
811 @var{category} is a number or a string containing one of the following values:
815 picture buffer allocations
823 memory management control operations (H.264)
830 per-block quantization parameter (QP)
838 visualize block types
840 visualize quantization parameter (QP), lower QP are tinted greener
842 @item -benchmark (@emph{global})
843 Show benchmarking information at the end of an encode.
844 Shows CPU time used and maximum memory consumption.
845 Maximum memory consumption is not supported on all systems,
846 it will usually display as 0 if not supported.
847 @item -benchmark_all (@emph{global})
848 Show benchmarking information during the encode.
849 Shows CPU time used in various steps (audio/video encode/decode).
850 @item -timelimit @var{duration} (@emph{global})
851 Exit after ffmpeg has been running for @var{duration} seconds.
852 @item -dump (@emph{global})
853 Dump each input packet to stderr.
854 @item -hex (@emph{global})
855 When dumping packets, also dump the payload.
856 @item -re (@emph{input})
857 Read input at native frame rate. Mainly used to simulate a grab device.
858 By default @command{ffmpeg} attempts to read the input(s) as fast as possible.
859 This option will slow down the reading of the input(s) to the native frame rate
860 of the input(s). It is useful for real-time output (e.g. live streaming). If
861 your input(s) is coming from some other live streaming source (through HTTP or
862 UDP for example) the server might already be in real-time, thus the option will
863 likely not be required. On the other hand, this is meaningful if your input(s)
864 is a file you are trying to push in real-time.
866 Loop over the input stream. Currently it works only for image
867 streams. This option is used for automatic FFserver testing.
868 This option is deprecated, use -loop 1.
869 @item -loop_output @var{number_of_times}
870 Repeatedly loop output for formats that support looping such as animated GIF
871 (0 will loop the output infinitely).
872 This option is deprecated, use -loop.
873 @item -vsync @var{parameter}
875 For compatibility reasons old values can be specified as numbers.
876 Newly added values will have to be specified as strings always.
880 Each frame is passed with its timestamp from the demuxer to the muxer.
882 Frames will be duplicated and dropped to achieve exactly the requested
885 Frames are passed through with their timestamp or dropped so as to
886 prevent 2 frames from having the same timestamp.
888 As passthrough but destroys all timestamps, making the muxer generate
889 fresh timestamps based on frame-rate.
891 Chooses between 1 and 2 depending on muxer capabilities. This is the
895 With -map you can select from which stream the timestamps should be
896 taken. You can leave either video or audio unchanged and sync the
897 remaining stream(s) to the unchanged one.
899 @item -async @var{samples_per_second}
900 Audio sync method. "Stretches/squeezes" the audio stream to match the timestamps,
901 the parameter is the maximum samples per second by which the audio is changed.
902 -async 1 is a special case where only the start of the audio stream is corrected
903 without any later correction.
904 This option has been deprecated. Use the @code{asyncts} audio filter instead.
906 Copy timestamps from input to output.
907 @item -copytb @var{mode}
908 Specify how to set the encoder timebase when stream copying. @var{mode} is an
909 integer numeric value, and can assume one of the following values:
913 Use the demuxer timebase.
915 The time base is copied to the output encoder from the corresponding input
916 demuxer. This is sometimes required to avoid non monotonically increasing
917 timestamps when copying video streams with variable frame rate.
920 Use the decoder timebase.
922 The time base is copied to the output encoder from the corresponding input
926 Try to make the choice automatically, in order to generate a sane output.
932 Finish encoding when the shortest input stream ends.
933 @item -dts_delta_threshold
934 Timestamp discontinuity delta threshold.
935 @item -muxdelay @var{seconds} (@emph{input})
936 Set the maximum demux-decode delay.
937 @item -muxpreload @var{seconds} (@emph{input})
938 Set the initial demux-decode delay.
939 @item -streamid @var{output-stream-index}:@var{new-value} (@emph{output})
940 Assign a new stream-id value to an output stream. This option should be
941 specified prior to the output filename to which it applies.
942 For the situation where multiple output files exist, a streamid
943 may be reassigned to a different value.
945 For example, to set the stream 0 PID to 33 and the stream 1 PID to 36 for
946 an output mpegts file:
948 ffmpeg -i infile -streamid 0:33 -streamid 1:36 out.ts
951 @item -bsf[:@var{stream_specifier}] @var{bitstream_filters} (@emph{output,per-stream})
952 Set bitstream filters for matching streams. @var{bistream_filters} is
953 a comma-separated list of bitstream filters. Use the @code{-bsfs} option
954 to get the list of bitstream filters.
956 ffmpeg -i h264.mp4 -c:v copy -bsf:v h264_mp4toannexb -an out.h264
959 ffmpeg -i file.mov -an -vn -bsf:s mov2textsub -c:s copy -f rawvideo sub.txt
962 @item -tag[:@var{stream_specifier}] @var{codec_tag} (@emph{per-stream})
963 Force a tag/fourcc for matching streams.
965 @item -timecode @var{hh}:@var{mm}:@var{ss}SEP@var{ff}
966 Specify Timecode for writing. @var{SEP} is ':' for non drop timecode and ';'
969 ffmpeg -i input.mpg -timecode 01:02:03.04 -r 30000/1001 -s ntsc output.mpg
972 @item -filter_complex @var{filtergraph} (@emph{global})
973 Define a complex filter graph, i.e. one with arbitrary number of inputs and/or
974 outputs. For simple graphs -- those with one input and one output of the same
975 type -- see the @option{-filter} options. @var{filtergraph} is a description of
976 the filter graph, as described in @ref{Filtergraph syntax}.
978 Input link labels must refer to input streams using the
979 @code{[file_index:stream_specifier]} syntax (i.e. the same as @option{-map}
980 uses). If @var{stream_specifier} matches multiple streams, the first one will be
981 used. An unlabeled input will be connected to the first unused input stream of
984 Output link labels are referred to with @option{-map}. Unlabeled outputs are
985 added to the first output file.
987 Note that with this option it is possible to use only lavfi sources without
990 For example, to overlay an image over video
992 ffmpeg -i video.mkv -i image.png -filter_complex '[0:v][1:v]overlay[out]' -map
995 Here @code{[0:v]} refers to the first video stream in the first input file,
996 which is linked to the first (main) input of the overlay filter. Similarly the
997 first video stream in the second input is linked to the second (overlay) input
1000 Assuming there is only one video stream in each input file, we can omit input
1001 labels, so the above is equivalent to
1003 ffmpeg -i video.mkv -i image.png -filter_complex 'overlay[out]' -map
1007 Furthermore we can omit the output label and the single output from the filter
1008 graph will be added to the output file automatically, so we can simply write
1010 ffmpeg -i video.mkv -i image.png -filter_complex 'overlay' out.mkv
1013 To generate 5 seconds of pure red video using lavfi @code{color} source:
1015 ffmpeg -filter_complex 'color=red' -t 5 out.mkv
1019 As a special exception, you can use a bitmap subtitle stream as input: it
1020 will be converted into a video with the same size as the largest video in
1021 the file, or 720×576 if no video is present. Note that this is an
1022 experimental and temporary solution. It will be removed once libavfilter has
1023 proper support for subtitles.
1025 For example, to hardcode subtitles on top of a DVB-T recording stored in
1026 MPEG-TS format, delaying the subtitles by 1 second:
1028 ffmpeg -i input.ts -filter_complex \
1029 '[#0x2ef] setpts=PTS+1/TB [sub] ; [#0x2d0] [sub] overlay' \
1030 -sn -map '#0x2dc' output.mkv
1032 (0x2d0, 0x2dc and 0x2ef are the MPEG-TS PIDs of respectively the video,
1033 audio and subtitles streams; 0:0, 0:3 and 0:7 would have worked too)
1035 @section Preset files
1036 A preset file contains a sequence of @var{option}=@var{value} pairs,
1037 one for each line, specifying a sequence of options which would be
1038 awkward to specify on the command line. Lines starting with the hash
1039 ('#') character are ignored and are used to provide comments. Check
1040 the @file{presets} directory in the FFmpeg source tree for examples.
1042 Preset files are specified with the @code{vpre}, @code{apre},
1043 @code{spre}, and @code{fpre} options. The @code{fpre} option takes the
1044 filename of the preset instead of a preset name as input and can be
1045 used for any kind of codec. For the @code{vpre}, @code{apre}, and
1046 @code{spre} options, the options specified in a preset file are
1047 applied to the currently selected codec of the same type as the preset
1050 The argument passed to the @code{vpre}, @code{apre}, and @code{spre}
1051 preset options identifies the preset file to use according to the
1054 First ffmpeg searches for a file named @var{arg}.ffpreset in the
1055 directories @file{$FFMPEG_DATADIR} (if set), and @file{$HOME/.ffmpeg}, and in
1056 the datadir defined at configuration time (usually @file{PREFIX/share/ffmpeg})
1057 or in a @file{ffpresets} folder along the executable on win32,
1058 in that order. For example, if the argument is @code{libvpx-1080p}, it will
1059 search for the file @file{libvpx-1080p.ffpreset}.
1061 If no such file is found, then ffmpeg will search for a file named
1062 @var{codec_name}-@var{arg}.ffpreset in the above-mentioned
1063 directories, where @var{codec_name} is the name of the codec to which
1064 the preset file options will be applied. For example, if you select
1065 the video codec with @code{-vcodec libvpx} and use @code{-vpre 1080p},
1066 then it will search for the file @file{libvpx-1080p.ffpreset}.
1074 For streaming at very low bitrate application, use a low frame rate
1075 and a small GOP size. This is especially true for RealVideo where
1076 the Linux player does not seem to be very fast, so it can miss
1077 frames. An example is:
1080 ffmpeg -g 3 -r 3 -t 10 -b:v 50k -s qcif -f rv10 /tmp/b.rm
1084 The parameter 'q' which is displayed while encoding is the current
1085 quantizer. The value 1 indicates that a very good quality could
1086 be achieved. The value 31 indicates the worst quality. If q=31 appears
1087 too often, it means that the encoder cannot compress enough to meet
1088 your bitrate. You must either increase the bitrate, decrease the
1089 frame rate or decrease the frame size.
1092 If your computer is not fast enough, you can speed up the
1093 compression at the expense of the compression ratio. You can use
1094 '-me zero' to speed up motion estimation, and '-g 0' to disable
1095 motion estimation completely (you have only I-frames, which means it
1096 is about as good as JPEG compression).
1099 To have very low audio bitrates, reduce the sampling frequency
1100 (down to 22050 Hz for MPEG audio, 22050 or 11025 for AC-3).
1103 To have a constant quality (but a variable bitrate), use the option
1104 '-qscale n' when 'n' is between 1 (excellent quality) and 31 (worst
1111 @c man begin EXAMPLES
1113 @section Preset files
1115 A preset file contains a sequence of @var{option=value} pairs, one for
1116 each line, specifying a sequence of options which can be specified also on
1117 the command line. Lines starting with the hash ('#') character are ignored and
1118 are used to provide comments. Empty lines are also ignored. Check the
1119 @file{presets} directory in the FFmpeg source tree for examples.
1121 Preset files are specified with the @code{pre} option, this option takes a
1122 preset name as input. FFmpeg searches for a file named @var{preset_name}.avpreset in
1123 the directories @file{$AVCONV_DATADIR} (if set), and @file{$HOME/.ffmpeg}, and in
1124 the data directory defined at configuration time (usually @file{$PREFIX/share/ffmpeg})
1125 in that order. For example, if the argument is @code{libx264-max}, it will
1126 search for the file @file{libx264-max.avpreset}.
1128 @section Video and Audio grabbing
1130 If you specify the input format and device then ffmpeg can grab video
1134 ffmpeg -f oss -i /dev/dsp -f video4linux2 -i /dev/video0 /tmp/out.mpg
1137 Or with an ALSA audio source (mono input, card id 1) instead of OSS:
1139 ffmpeg -f alsa -ac 1 -i hw:1 -f video4linux2 -i /dev/video0 /tmp/out.mpg
1142 Note that you must activate the right video source and channel before
1143 launching ffmpeg with any TV viewer such as
1144 @uref{http://linux.bytesex.org/xawtv/, xawtv} by Gerd Knorr. You also
1145 have to set the audio recording levels correctly with a
1148 @section X11 grabbing
1150 Grab the X11 display with ffmpeg via
1153 ffmpeg -f x11grab -s cif -r 25 -i :0.0 /tmp/out.mpg
1156 0.0 is display.screen number of your X11 server, same as
1157 the DISPLAY environment variable.
1160 ffmpeg -f x11grab -s cif -r 25 -i :0.0+10,20 /tmp/out.mpg
1163 0.0 is display.screen number of your X11 server, same as the DISPLAY environment
1164 variable. 10 is the x-offset and 20 the y-offset for the grabbing.
1166 @section Video and Audio file format conversion
1168 Any supported file format and protocol can serve as input to ffmpeg:
1173 You can use YUV files as input:
1176 ffmpeg -i /tmp/test%d.Y /tmp/out.mpg
1179 It will use the files:
1181 /tmp/test0.Y, /tmp/test0.U, /tmp/test0.V,
1182 /tmp/test1.Y, /tmp/test1.U, /tmp/test1.V, etc...
1185 The Y files use twice the resolution of the U and V files. They are
1186 raw files, without header. They can be generated by all decent video
1187 decoders. You must specify the size of the image with the @option{-s} option
1188 if ffmpeg cannot guess it.
1191 You can input from a raw YUV420P file:
1194 ffmpeg -i /tmp/test.yuv /tmp/out.avi
1197 test.yuv is a file containing raw YUV planar data. Each frame is composed
1198 of the Y plane followed by the U and V planes at half vertical and
1199 horizontal resolution.
1202 You can output to a raw YUV420P file:
1205 ffmpeg -i mydivx.avi hugefile.yuv
1209 You can set several input files and output files:
1212 ffmpeg -i /tmp/a.wav -s 640x480 -i /tmp/a.yuv /tmp/a.mpg
1215 Converts the audio file a.wav and the raw YUV video file a.yuv
1219 You can also do audio and video conversions at the same time:
1222 ffmpeg -i /tmp/a.wav -ar 22050 /tmp/a.mp2
1225 Converts a.wav to MPEG audio at 22050 Hz sample rate.
1228 You can encode to several formats at the same time and define a
1229 mapping from input stream to output streams:
1232 ffmpeg -i /tmp/a.wav -map 0:a -b:a 64k /tmp/a.mp2 -map 0:a -b:a 128k /tmp/b.mp2
1235 Converts a.wav to a.mp2 at 64 kbits and to b.mp2 at 128 kbits. '-map
1236 file:index' specifies which input stream is used for each output
1237 stream, in the order of the definition of output streams.
1240 You can transcode decrypted VOBs:
1243 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
1246 This is a typical DVD ripping example; the input is a VOB file, the
1247 output an AVI file with MPEG-4 video and MP3 audio. Note that in this
1248 command we use B-frames so the MPEG-4 stream is DivX5 compatible, and
1249 GOP size is 300 which means one intra frame every 10 seconds for 29.97fps
1250 input video. Furthermore, the audio stream is MP3-encoded so you need
1251 to enable LAME support by passing @code{--enable-libmp3lame} to configure.
1252 The mapping is particularly useful for DVD transcoding
1253 to get the desired audio language.
1255 NOTE: To see the supported input formats, use @code{ffmpeg -formats}.
1258 You can extract images from a video, or create a video from many images:
1260 For extracting images from a video:
1262 ffmpeg -i foo.avi -r 1 -s WxH -f image2 foo-%03d.jpeg
1265 This will extract one video frame per second from the video and will
1266 output them in files named @file{foo-001.jpeg}, @file{foo-002.jpeg},
1267 etc. Images will be rescaled to fit the new WxH values.
1269 If you want to extract just a limited number of frames, you can use the
1270 above command in combination with the -vframes or -t option, or in
1271 combination with -ss to start extracting from a certain point in time.
1273 For creating a video from many images:
1275 ffmpeg -f image2 -i foo-%03d.jpeg -r 12 -s WxH foo.avi
1278 The syntax @code{foo-%03d.jpeg} specifies to use a decimal number
1279 composed of three digits padded with zeroes to express the sequence
1280 number. It is the same syntax supported by the C printf function, but
1281 only formats accepting a normal integer are suitable.
1283 When importing an image sequence, -i also supports expanding
1284 shell-like wildcard patterns (globbing) internally, by selecting the
1285 image2-specific @code{-pattern_type glob} option.
1287 For example, for creating a video from filenames matching the glob pattern
1290 ffmpeg -f image2 -pattern_type glob -i 'foo-*.jpeg' -r 12 -s WxH foo.avi
1294 You can put many streams of the same type in the output:
1297 ffmpeg -i test1.avi -i test2.avi -map 0.3 -map 0.2 -map 0.1 -map 0.0 -c copy test12.nut
1300 The resulting output file @file{test12.avi} will contain first four streams from
1301 the input file in reverse order.
1304 To force CBR video output:
1306 ffmpeg -i myfile.avi -b 4000k -minrate 4000k -maxrate 4000k -bufsize 1835k out.m2v
1310 The four options lmin, lmax, mblmin and mblmax use 'lambda' units,
1311 but you may use the QP2LAMBDA constant to easily convert from 'q' units:
1313 ffmpeg -i src.ext -lmax 21*QP2LAMBDA dst.ext
1319 @include syntax.texi
1321 @include decoders.texi
1322 @include encoders.texi
1323 @include demuxers.texi
1324 @include muxers.texi
1325 @include indevs.texi
1326 @include outdevs.texi
1327 @include protocols.texi
1328 @include bitstream_filters.texi
1329 @include filters.texi
1330 @include metadata.texi
1335 @settitle ffmpeg video converter
1337 @c man begin SEEALSO
1338 ffplay(1), ffprobe(1), ffserver(1) and the FFmpeg HTML documentation
1341 @c man begin AUTHORS