1 \input texinfo @c -*- texinfo -*-
3 @settitle ffmpeg Documentation
5 @center @titlefont{ffmpeg Documentation}
14 ffmpeg [@var{global_options}] @{[@var{input_file_options}] -i @file{input_file}@} ... @{[@var{output_file_options}] @file{output_file}@} ...
17 @c man begin DESCRIPTION
19 ffmpeg is a very fast video and audio converter that can also grab from
20 a live audio/video source. It can also convert between arbitrary sample
21 rates and resize video on the fly with a high quality polyphase filter.
23 ffmpeg reads from an arbitrary number of input "files" (which can be regular
24 files, pipes, network streams, grabbing devices, etc.), specified by the
25 @code{-i} option, and writes to an arbitrary number of output "files", which are
26 specified by a plain output filename. Anything found on the command line which
27 cannot be interpreted as an option is considered to be an output filename.
29 Each input or output file can in principle contain any number of streams of
30 different types (video/audio/subtitle/attachment/data). Allowed number and/or
31 types of streams can be limited by the container format. Selecting, which
32 streams from which inputs go into output, is done either automatically or with
33 the @code{-map} option (see the Stream selection chapter).
35 To refer to input files in options, you must use their indices (0-based). E.g.
36 the first input file is @code{0}, the second is @code{1} etc. Similarly, streams
37 within a file are referred to by their indices. E.g. @code{2:3} refers to the
38 fourth stream in the third input file. See also the Stream specifiers chapter.
40 As a general rule, options are applied to the next specified
41 file. Therefore, order is important, and you can have the same
42 option on the command line multiple times. Each occurrence is
43 then applied to the next input or output file.
44 Exceptions from this rule are the global options (e.g. verbosity level),
45 which should be specified first.
47 Do not mix input and output files -- first specify all input files, then all
48 output files. Also do not mix options which belong to different files. All
49 options apply ONLY to the next input or output file and are reset between files.
53 To set the video bitrate of the output file to 64kbit/s:
55 ffmpeg -i input.avi -b:v 64k -bufsize 64k output.avi
59 To force the frame rate of the output file to 24 fps:
61 ffmpeg -i input.avi -r 24 output.avi
65 To force the frame rate of the input file (valid for raw formats only)
66 to 1 fps and the frame rate of the output file to 24 fps:
68 ffmpeg -r 1 -i input.m2v -r 24 output.avi
72 The format option may be needed for raw input files.
74 @c man end DESCRIPTION
76 @chapter Detailed description
77 @c man begin DETAILED DESCRIPTION
79 The transcoding process in @command{ffmpeg} for each output can be described by
80 the following diagram:
83 _______ ______________ _________ ______________ ________
85 | input | demuxer | encoded data | decoder | decoded | encoder | encoded data | muxer | output |
86 | file | ---------> | packets | ---------> | frames | ---------> | packets | -------> | file |
87 |_______| |______________| |_________| |______________| |________|
91 @command{ffmpeg} calls the libavformat library (containing demuxers) to read
92 input files and get packets containing encoded data from them. When there are
93 multiple input files, @command{ffmpeg} tries to keep them synchronized by
94 tracking lowest timestamp on any active input stream.
96 Encoded packets are then passed to the decoder (unless streamcopy is selected
97 for the stream, see further for a description). The decoder produces
98 uncompressed frames (raw video/PCM audio/...) which can be processed further by
99 filtering (see next section). After filtering the frames are passed to the
100 encoder, which encodes them and outputs encoded packets again. Finally those are
101 passed to the muxer, which writes the encoded packets to the output file.
104 Before encoding, @command{ffmpeg} can process raw audio and video frames using
105 filters from the libavfilter library. Several chained filters form a filter
106 graph. @command{ffmpeg} distinguishes between two types of filtergraphs -
109 @subsection Simple filtergraphs
110 Simple filtergraphs are those that have exactly one input and output, both of
111 the same type. In the above diagram they can be represented by simply inserting
112 an additional step between decoding and encoding:
115 _________ __________ ______________
117 | decoded | simple filtergraph | filtered | encoder | encoded data |
118 | frames | -------------------> | frames | ---------> | packets |
119 |_________| |__________| |______________|
123 Simple filtergraphs are configured with the per-stream @option{-filter} option
124 (with @option{-vf} and @option{-af} aliases for video and audio respectively).
125 A simple filtergraph for video can look for example like this:
128 _______ _____________ _______ _____ ________
130 | input | ---> | deinterlace | ---> | scale | ---> | fps | ---> | output |
131 |_______| |_____________| |_______| |_____| |________|
135 Note that some filters change frame properties but not frame contents. E.g. the
136 @code{fps} filter in the example above changes number of frames, but does not
137 touch the frame contents. Another example is the @code{setpts} filter, which
138 only sets timestamps and otherwise passes the frames unchanged.
140 @subsection Complex filtergraphs
141 Complex filtergraphs are those which cannot be described as simply a linear
142 processing chain applied to one stream. This is the case e.g. when the graph has
143 more than one input and/or output, or when output stream type is different from
144 input. They can be represented with the following diagram:
149 | input 0 |\ __________
151 \ _________ /| output 0 |
153 _________ \| complex | /
155 | input 1 |---->| filter |\
156 |_________| | | \ __________
159 _________ / |_________| |__________|
166 Complex filtergraphs are configured with the @option{-filter_complex} option.
167 Note that this option is global, since a complex filtergraph by its nature
168 cannot be unambiguously associated with a single stream or file.
170 A trivial example of a complex filtergraph is the @code{overlay} filter, which
171 has two video inputs and one video output, containing one video overlaid on top
172 of the other. Its audio counterpart is the @code{amix} filter.
175 Stream copy is a mode selected by supplying the @code{copy} parameter to the
176 @option{-codec} option. It makes @command{ffmpeg} omit the decoding and encoding
177 step for the specified stream, so it does only demuxing and muxing. It is useful
178 for changing the container format or modifying container-level metadata. The
179 diagram above will in this case simplify to this:
182 _______ ______________ ________
184 | input | demuxer | encoded data | muxer | output |
185 | file | ---------> | packets | -------> | file |
186 |_______| |______________| |________|
190 Since there is no decoding or encoding, it is very fast and there is no quality
191 loss. However it might not work in some cases because of many factors. Applying
192 filters is obviously also impossible, since filters work on uncompressed data.
194 @c man end DETAILED DESCRIPTION
196 @chapter Stream selection
197 @c man begin STREAM SELECTION
199 By default ffmpeg includes only one stream of each type (video, audio, subtitle)
200 present in the input files and adds them to each output file. It picks the
201 "best" of each based upon the following criteria; for video it is the stream
202 with the highest resolution, for audio the stream with the most channels, for
203 subtitle it's the first subtitle stream. In the case where several streams of
204 the same type rate equally, the lowest numbered stream is chosen.
206 You can disable some of those defaults by using @code{-vn/-an/-sn} options. For
207 full manual control, use the @code{-map} option, which disables the defaults just
210 @c man end STREAM SELECTION
215 @include avtools-common-opts.texi
217 @section Main options
221 @item -f @var{fmt} (@emph{input/output})
222 Force input or output file format. The format is normally auto detected for input
223 files and guessed from file extension for output files, so this option is not
224 needed in most cases.
226 @item -i @var{filename} (@emph{input})
229 @item -y (@emph{global})
230 Overwrite output files without asking.
232 @item -n (@emph{global})
233 Do not overwrite output files but exit if file exists.
235 @item -c[:@var{stream_specifier}] @var{codec} (@emph{input/output,per-stream})
236 @itemx -codec[:@var{stream_specifier}] @var{codec} (@emph{input/output,per-stream})
237 Select an encoder (when used before an output file) or a decoder (when used
238 before an input file) for one or more streams. @var{codec} is the name of a
239 decoder/encoder or a special value @code{copy} (output only) to indicate that
240 the stream is not to be re-encoded.
244 ffmpeg -i INPUT -map 0 -c:v libx264 -c:a copy OUTPUT
246 encodes all video streams with libx264 and copies all audio streams.
248 For each stream, the last matching @code{c} option is applied, so
250 ffmpeg -i INPUT -map 0 -c copy -c:v:1 libx264 -c:a:137 libvorbis OUTPUT
252 will copy all the streams except the second video, which will be encoded with
253 libx264, and the 138th audio, which will be encoded with libvorbis.
255 @item -t @var{duration} (@emph{output})
256 Stop writing the output after its duration reaches @var{duration}.
257 @var{duration} may be a number in seconds, or in @code{hh:mm:ss[.xxx]} form.
259 @item -fs @var{limit_size} (@emph{output})
260 Set the file size limit, expressed in bytes.
262 @item -ss @var{position} (@emph{input/output})
263 When used as an input option (before @code{-i}), seeks in this input file to
264 @var{position}. When used as an output option (before an output filename),
265 decodes but discards input until the timestamps reach @var{position}. This is
266 slower, but more accurate.
268 @var{position} may be either in seconds or in @code{hh:mm:ss[.xxx]} form.
270 @item -itsoffset @var{offset} (@emph{input})
271 Set the input time offset in seconds.
272 @code{[-]hh:mm:ss[.xxx]} syntax is also supported.
273 The offset is added to the timestamps of the input files.
274 Specifying a positive offset means that the corresponding
275 streams are delayed by @var{offset} seconds.
277 @item -timestamp @var{time} (@emph{output})
278 Set the recording timestamp in the container.
279 The syntax for @var{time} is:
281 now|([(YYYY-MM-DD|YYYYMMDD)[T|t| ]]((HH:MM:SS[.m...])|(HHMMSS[.m...]))[Z|z])
283 If the value is "now" it takes the current time.
284 Time is local time unless 'Z' or 'z' is appended, in which case it is
286 If the year-month-day part is not specified it takes the current
289 @item -metadata[:metadata_specifier] @var{key}=@var{value} (@emph{output,per-metadata})
290 Set a metadata key/value pair.
292 An optional @var{metadata_specifier} may be given to set metadata
293 on streams or chapters. See @code{-map_metadata} documentation for
296 This option overrides metadata set with @code{-map_metadata}. It is
297 also possible to delete metadata by using an empty value.
299 For example, for setting the title in the output file:
301 ffmpeg -i in.avi -metadata title="my title" out.flv
304 To set the language of the first audio stream:
306 ffmpeg -i INPUT -metadata:s:a:1 language=eng OUTPUT
309 @item -target @var{type} (@emph{output})
310 Specify target file type (@code{vcd}, @code{svcd}, @code{dvd}, @code{dv},
311 @code{dv50}). @var{type} may be prefixed with @code{pal-}, @code{ntsc-} or
312 @code{film-} to use the corresponding standard. All the format options
313 (bitrate, codecs, buffer sizes) are then set automatically. You can just type:
316 ffmpeg -i myfile.avi -target vcd /tmp/vcd.mpg
319 Nevertheless you can specify additional options as long as you know
320 they do not conflict with the standard, as in:
323 ffmpeg -i myfile.avi -target vcd -bf 2 /tmp/vcd.mpg
326 @item -dframes @var{number} (@emph{output})
327 Set the number of data frames to record. This is an alias for @code{-frames:d}.
329 @item -frames[:@var{stream_specifier}] @var{framecount} (@emph{output,per-stream})
330 Stop writing to the stream after @var{framecount} frames.
332 @item -q[:@var{stream_specifier}] @var{q} (@emph{output,per-stream})
333 @itemx -qscale[:@var{stream_specifier}] @var{q} (@emph{output,per-stream})
334 Use fixed quality scale (VBR). The meaning of @var{q} is
337 @item -filter[:@var{stream_specifier}] @var{filter_graph} (@emph{output,per-stream})
338 @var{filter_graph} is a description of the filter graph to apply to
339 the stream. Use @code{-filters} to show all the available filters
340 (including also sources and sinks).
342 See also the @option{-filter_complex} option if you want to create filter graphs
343 with multiple inputs and/or outputs.
344 @item -pre[:@var{stream_specifier}] @var{preset_name} (@emph{output,per-stream})
345 Specify the preset for matching stream(s).
347 @item -stats (@emph{global})
348 Print encoding progress/statistics. On by default.
350 @item -progress @var{url} (@emph{global})
351 Send program-friendly progress information to @var{url}.
353 Progress information is written approximately every second and at the end of
354 the encoding process. It is made of "@var{key}=@var{value}" lines. @var{key}
355 consists of only alphanumeric characters. The last key of a sequence of
356 progress information is always "progress".
359 Enable interaction on standard input. On by default unless standard input is
360 used as an input. To explicitly disable interaction you need to specify
363 Disabling interaction on standard input is useful, for example, if
364 ffmpeg is in the background process group. Roughly the same result can
365 be achieved with @code{ffmpeg ... < /dev/null} but it requires a
368 @item -debug_ts (@emph{global})
369 Print timestamp information. It is off by default. This option is
370 mostly useful for testing and debugging purposes, and the output
371 format may change from one version to another, so it should not be
372 employed by portable scripts.
374 See also the option @code{-fdebug ts}.
376 @item -attach @var{filename} (@emph{output})
377 Add an attachment to the output file. This is supported by a few formats
378 like Matroska for e.g. fonts used in rendering subtitles. Attachments
379 are implemented as a specific type of stream, so this option will add
380 a new stream to the file. It is then possible to use per-stream options
381 on this stream in the usual way. Attachment streams created with this
382 option will be created after all the other streams (i.e. those created
383 with @code{-map} or automatic mappings).
385 Note that for Matroska you also have to set the mimetype metadata tag:
387 ffmpeg -i INPUT -attach DejaVuSans.ttf -metadata:s:2 mimetype=application/x-truetype-font out.mkv
389 (assuming that the attachment stream will be third in the output file).
391 @item -dump_attachment[:@var{stream_specifier}] @var{filename} (@emph{input,per-stream})
392 Extract the matching attachment stream into a file named @var{filename}. If
393 @var{filename} is empty, then the value of the @code{filename} metadata tag
396 E.g. to extract the first attachment to a file named 'out.ttf':
398 ffmpeg -dump_attachment:t:0 out.ttf INPUT
400 To extract all attachments to files determined by the @code{filename} tag:
402 ffmpeg -dump_attachment:t "" INPUT
405 Technical note -- attachments are implemented as codec extradata, so this
406 option can actually be used to extract extradata from any stream, not just
411 @section Video Options
414 @item -vframes @var{number} (@emph{output})
415 Set the number of video frames to record. This is an alias for @code{-frames:v}.
416 @item -r[:@var{stream_specifier}] @var{fps} (@emph{input/output,per-stream})
417 Set frame rate (Hz value, fraction or abbreviation).
419 As an input option, ignore any timestamps stored in the file and instead
420 generate timestamps assuming constant frame rate @var{fps}.
422 As an output option, duplicate or drop input frames to achieve constant output
423 frame rate @var{fps}.
425 @item -s[:@var{stream_specifier}] @var{size} (@emph{input/output,per-stream})
428 As an input option, this is a shortcut for the @option{video_size} private
429 option, recognized by some demuxers for which the frame size is either not
430 stored in the file or is configurable -- e.g. raw video or video grabbers.
432 As an output option, this inserts the @code{scale} video filter to the
433 @emph{end} of the corresponding filtergraph. Please use the @code{scale} filter
434 directly to insert it at the beginning or some other place.
436 The format is @samp{wxh} (default - same as source).
438 @item -aspect[:@var{stream_specifier}] @var{aspect} (@emph{output,per-stream})
439 Set the video display aspect ratio specified by @var{aspect}.
441 @var{aspect} can be a floating point number string, or a string of the
442 form @var{num}:@var{den}, where @var{num} and @var{den} are the
443 numerator and denominator of the aspect ratio. For example "4:3",
444 "16:9", "1.3333", and "1.7777" are valid argument values.
446 @item -croptop @var{size}
447 @item -cropbottom @var{size}
448 @item -cropleft @var{size}
449 @item -cropright @var{size}
450 All the crop options have been removed. Use -vf
451 crop=width:height:x:y instead.
453 @item -padtop @var{size}
454 @item -padbottom @var{size}
455 @item -padleft @var{size}
456 @item -padright @var{size}
457 @item -padcolor @var{hex_color}
458 All the pad options have been removed. Use -vf
459 pad=width:height:x:y:color instead.
461 @item -vn (@emph{output})
462 Disable video recording.
464 @item -vcodec @var{codec} (@emph{output})
465 Set the video codec. This is an alias for @code{-codec:v}.
467 @item -pass[:@var{stream_specifier}] @var{n} (@emph{output,per-stream})
468 Select the pass number (1 or 2). It is used to do two-pass
469 video encoding. The statistics of the video are recorded in the first
470 pass into a log file (see also the option -passlogfile),
471 and in the second pass that log file is used to generate the video
472 at the exact requested bitrate.
473 On pass 1, you may just deactivate audio and set output to null,
474 examples for Windows and Unix:
476 ffmpeg -i foo.mov -c:v libxvid -pass 1 -an -f rawvideo -y NUL
477 ffmpeg -i foo.mov -c:v libxvid -pass 1 -an -f rawvideo -y /dev/null
480 @item -passlogfile[:@var{stream_specifier}] @var{prefix} (@emph{output,per-stream})
481 Set two-pass log file name prefix to @var{prefix}, the default file name
482 prefix is ``ffmpeg2pass''. The complete file name will be
483 @file{PREFIX-N.log}, where N is a number specific to the output
486 @item -vlang @var{code}
487 Set the ISO 639 language code (3 letters) of the current video stream.
489 @item -vf @var{filter_graph} (@emph{output})
490 @var{filter_graph} is a description of the filter graph to apply to
492 Use the option "-filters" to show all the available filters (including
493 also sources and sinks). This is an alias for @code{-filter:v}.
497 @section Advanced Video Options
500 @item -pix_fmt[:@var{stream_specifier}] @var{format} (@emph{input/output,per-stream})
501 Set pixel format. Use @code{-pix_fmts} to show all the supported
503 If the selected pixel format can not be selected, ffmpeg will print a
504 warning and select the best pixel format supported by the encoder.
505 If @var{pix_fmt} is prefixed by a @code{+}, ffmpeg will exit with an error
506 if the requested pixel format can not be selected, and automatic conversions
507 inside filter graphs are disabled.
508 If @var{pix_fmt} is a single @code{+}, ffmpeg selects the same pixel format
509 as the input (or graph output) and automatic conversions are disabled.
511 @item -sws_flags @var{flags} (@emph{input/output})
516 @item -rc_override[:@var{stream_specifier}] @var{override} (@emph{output,per-stream})
517 Rate control override for specific intervals, formatted as "int,int,int"
518 list separated with slashes. Two first values are the beginning and
519 end frame numbers, last one is quantizer to use if positive, or quality
523 Deinterlace pictures.
524 This option is deprecated since the deinterlacing is very low quality.
525 Use the yadif filter with @code{-filter:v yadif}.
527 Force interlacing support in encoder (MPEG-2 and MPEG-4 only).
528 Use this option if your input file is interlaced and you want
529 to keep the interlaced format for minimum losses.
530 The alternative is to deinterlace the input stream with
531 @option{-deinterlace}, but deinterlacing introduces losses.
533 Calculate PSNR of compressed frames.
535 Dump video coding statistics to @file{vstats_HHMMSS.log}.
536 @item -vstats_file @var{file}
537 Dump video coding statistics to @var{file}.
538 @item -top[:@var{stream_specifier}] @var{n} (@emph{output,per-stream})
539 top=1/bottom=0/auto=-1 field first
540 @item -dc @var{precision}
542 @item -vtag @var{fourcc/tag} (@emph{output})
543 Force video tag/fourcc. This is an alias for @code{-tag:v}.
544 @item -qphist (@emph{global})
546 @item -vbsf @var{bitstream_filter}
548 @item -force_key_frames[:@var{stream_specifier}] @var{time}[,@var{time}...] (@emph{output,per-stream})
549 Force key frames at the specified timestamps, more precisely at the first
550 frames after each specified time.
551 This option can be useful to ensure that a seek point is present at a
552 chapter mark or any other designated place in the output file.
553 The timestamps must be specified in ascending order.
555 @item -copyinkf[:@var{stream_specifier}] (@emph{output,per-stream})
556 When doing stream copy, copy also non-key frames found at the
560 @section Audio Options
563 @item -aframes @var{number} (@emph{output})
564 Set the number of audio frames to record. This is an alias for @code{-frames:a}.
565 @item -ar[:@var{stream_specifier}] @var{freq} (@emph{input/output,per-stream})
566 Set the audio sampling frequency. For output streams it is set by
567 default to the frequency of the corresponding input stream. For input
568 streams this option only makes sense for audio grabbing devices and raw
569 demuxers and is mapped to the corresponding demuxer options.
570 @item -aq @var{q} (@emph{output})
571 Set the audio quality (codec-specific, VBR). This is an alias for -q:a.
572 @item -ac[:@var{stream_specifier}] @var{channels} (@emph{input/output,per-stream})
573 Set the number of audio channels. For output streams it is set by
574 default to the number of input audio channels. For input streams
575 this option only makes sense for audio grabbing devices and raw demuxers
576 and is mapped to the corresponding demuxer options.
577 @item -an (@emph{output})
578 Disable audio recording.
579 @item -acodec @var{codec} (@emph{input/output})
580 Set the audio codec. This is an alias for @code{-codec:a}.
581 @item -sample_fmt[:@var{stream_specifier}] @var{sample_fmt} (@emph{output,per-stream})
582 Set the audio sample format. Use @code{-sample_fmts} to get a list
583 of supported sample formats.
584 @item -af @var{filter_graph} (@emph{output})
585 @var{filter_graph} is a description of the filter graph to apply to
587 Use the option "-filters" to show all the available filters (including
588 also sources and sinks). This is an alias for @code{-filter:a}.
591 @section Advanced Audio options:
594 @item -atag @var{fourcc/tag} (@emph{output})
595 Force audio tag/fourcc. This is an alias for @code{-tag:a}.
596 @item -absf @var{bitstream_filter}
600 @section Subtitle options:
603 @item -slang @var{code}
604 Set the ISO 639 language code (3 letters) of the current subtitle stream.
605 @item -scodec @var{codec} (@emph{input/output})
606 Set the subtitle codec. This is an alias for @code{-codec:s}.
607 @item -sn (@emph{output})
608 Disable subtitle recording.
609 @item -sbsf @var{bitstream_filter}
613 @section Advanced Subtitle options:
617 @item -fix_sub_duration
618 Fix subtitles durations. For each subtitle, wait for the next packet in the
619 same stream and adjust the duration of the first to avoid overlap. This is
620 necessary with some subtitles codecs, especially DVB subtitles, because the
621 duration in the original packet is only a rough estimate and the end is
622 actually marked by an empty subtitle frame. Failing to use this option when
623 necessary can result in exaggerated durations or muxing failures due to
624 non-monotonic timestamps.
626 Note that this option will delay the output of all data until the next
627 subtitle packet is decoded: it may increase memory consumption and latency a
632 @section Advanced options
635 @item -map [-]@var{input_file_id}[:@var{stream_specifier}][,@var{sync_file_id}[:@var{stream_specifier}]] | @var{[linklabel]} (@emph{output})
637 Designate one or more input streams as a source for the output file. Each input
638 stream is identified by the input file index @var{input_file_id} and
639 the input stream index @var{input_stream_id} within the input
640 file. Both indices start at 0. If specified,
641 @var{sync_file_id}:@var{stream_specifier} sets which input stream
642 is used as a presentation sync reference.
644 The first @code{-map} option on the command line specifies the
645 source for output stream 0, the second @code{-map} option specifies
646 the source for output stream 1, etc.
648 A @code{-} character before the stream identifier creates a "negative" mapping.
649 It disables matching streams from already created mappings.
651 An alternative @var{[linklabel]} form will map outputs from complex filter
652 graphs (see the @option{-filter_complex} option) to the output file.
653 @var{linklabel} must correspond to a defined output link label in the graph.
655 For example, to map ALL streams from the first input file to output
657 ffmpeg -i INPUT -map 0 output
660 For example, if you have two audio streams in the first input file,
661 these streams are identified by "0:0" and "0:1". You can use
662 @code{-map} to select which streams to place in an output file. For
665 ffmpeg -i INPUT -map 0:1 out.wav
667 will map the input stream in @file{INPUT} identified by "0:1" to
668 the (single) output stream in @file{out.wav}.
670 For example, to select the stream with index 2 from input file
671 @file{a.mov} (specified by the identifier "0:2"), and stream with
672 index 6 from input @file{b.mov} (specified by the identifier "1:6"),
673 and copy them to the output file @file{out.mov}:
675 ffmpeg -i a.mov -i b.mov -c copy -map 0:2 -map 1:6 out.mov
678 To select all video and the third audio stream from an input file:
680 ffmpeg -i INPUT -map 0:v -map 0:a:2 OUTPUT
683 To map all the streams except the second audio, use negative mappings
685 ffmpeg -i INPUT -map 0 -map -0:a:1 OUTPUT
688 Note that using this option disables the default mappings for this output file.
690 @item -map_channel [@var{input_file_id}.@var{stream_specifier}.@var{channel_id}|-1][:@var{output_file_id}.@var{stream_specifier}]
691 Map an audio channel from a given input to an output. If
692 @var{output_file_id}.@var{stream_specifier} is not set, the audio channel will
693 be mapped on all the audio streams.
695 Using "-1" instead of
696 @var{input_file_id}.@var{stream_specifier}.@var{channel_id} will map a muted
699 For example, assuming @var{INPUT} is a stereo audio file, you can switch the
700 two audio channels with the following command:
702 ffmpeg -i INPUT -map_channel 0.0.1 -map_channel 0.0.0 OUTPUT
705 If you want to mute the first channel and keep the second:
707 ffmpeg -i INPUT -map_channel -1 -map_channel 0.0.1 OUTPUT
710 The order of the "-map_channel" option specifies the order of the channels in
711 the output stream. The output channel layout is guessed from the number of
712 channels mapped (mono if one "-map_channel", stereo if two, etc.). Using "-ac"
713 in combination of "-map_channel" makes the channel gain levels to be updated if
714 input and output channel layouts don't match (for instance two "-map_channel"
715 options and "-ac 6").
717 You can also extract each channel of an input to specific outputs; the following
718 command extracts two channels of the @var{INPUT} audio stream (file 0, stream 0)
719 to the respective @var{OUTPUT_CH0} and @var{OUTPUT_CH1} outputs:
721 ffmpeg -i INPUT -map_channel 0.0.0 OUTPUT_CH0 -map_channel 0.0.1 OUTPUT_CH1
724 The following example splits the channels of a stereo input into two separate
725 streams, which are put into the same output file:
727 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
730 Note that currently each output stream can only contain channels from a single
731 input stream; you can't for example use "-map_channel" to pick multiple input
732 audio channels contained in different streams (from the same or different files)
733 and merge them into a single output stream. It is therefore not currently
734 possible, for example, to turn two separate mono streams into a single stereo
735 stream. However splitting a stereo stream into two single channel mono streams
738 If you need this feature, a possible workaround is to use the @emph{amerge}
739 filter. For example, if you need to merge a media (here @file{input.mkv}) with 2
740 mono audio streams into one single stereo channel audio stream (and keep the
741 video stream), you can use the following command:
743 ffmpeg -i input.mkv -filter_complex "[0:1] [0:2] amerge" -c:a pcm_s16le -c:v copy output.mkv
746 @item -map_metadata[:@var{metadata_spec_out}] @var{infile}[:@var{metadata_spec_in}] (@emph{output,per-metadata})
747 Set metadata information of the next output file from @var{infile}. Note that
748 those are file indices (zero-based), not filenames.
749 Optional @var{metadata_spec_in/out} parameters specify, which metadata to copy.
750 A metadata specifier can have the following forms:
753 global metadata, i.e. metadata that applies to the whole file
755 @item @var{s}[:@var{stream_spec}]
756 per-stream metadata. @var{stream_spec} is a stream specifier as described
757 in the @ref{Stream specifiers} chapter. In an input metadata specifier, the first
758 matching stream is copied from. In an output metadata specifier, all matching
759 streams are copied to.
761 @item @var{c}:@var{chapter_index}
762 per-chapter metadata. @var{chapter_index} is the zero-based chapter index.
764 @item @var{p}:@var{program_index}
765 per-program metadata. @var{program_index} is the zero-based program index.
767 If metadata specifier is omitted, it defaults to global.
769 By default, global metadata is copied from the first input file,
770 per-stream and per-chapter metadata is copied along with streams/chapters. These
771 default mappings are disabled by creating any mapping of the relevant type. A negative
772 file index can be used to create a dummy mapping that just disables automatic copying.
774 For example to copy metadata from the first stream of the input file to global metadata
777 ffmpeg -i in.ogg -map_metadata 0:s:0 out.mp3
780 To do the reverse, i.e. copy global metadata to all audio streams:
782 ffmpeg -i in.mkv -map_metadata:s:a 0:g out.mkv
784 Note that simple @code{0} would work as well in this example, since global
785 metadata is assumed by default.
787 @item -map_chapters @var{input_file_index} (@emph{output})
788 Copy chapters from input file with index @var{input_file_index} to the next
789 output file. If no chapter mapping is specified, then chapters are copied from
790 the first input file with at least one chapter. Use a negative file index to
791 disable any chapter copying.
793 @item -benchmark (@emph{global})
794 Show benchmarking information at the end of an encode.
795 Shows CPU time used and maximum memory consumption.
796 Maximum memory consumption is not supported on all systems,
797 it will usually display as 0 if not supported.
798 @item -benchmark_all (@emph{global})
799 Show benchmarking information during the encode.
800 Shows CPU time used in various steps (audio/video encode/decode).
801 @item -timelimit @var{duration} (@emph{global})
802 Exit after ffmpeg has been running for @var{duration} seconds.
803 @item -dump (@emph{global})
804 Dump each input packet to stderr.
805 @item -hex (@emph{global})
806 When dumping packets, also dump the payload.
807 @item -re (@emph{input})
808 Read input at native frame rate. Mainly used to simulate a grab device.
809 By default @command{ffmpeg} attempts to read the input(s) as fast as possible.
810 This option will slow down the reading of the input(s) to the native frame rate
811 of the input(s). It is useful for real-time output (e.g. live streaming). If
812 your input(s) is coming from some other live streaming source (through HTTP or
813 UDP for example) the server might already be in real-time, thus the option will
814 likely not be required. On the other hand, this is meaningful if your input(s)
815 is a file you are trying to push in real-time.
817 Loop over the input stream. Currently it works only for image
818 streams. This option is used for automatic FFserver testing.
819 This option is deprecated, use -loop 1.
820 @item -loop_output @var{number_of_times}
821 Repeatedly loop output for formats that support looping such as animated GIF
822 (0 will loop the output infinitely).
823 This option is deprecated, use -loop.
824 @item -vsync @var{parameter}
826 For compatibility reasons old values can be specified as numbers.
827 Newly added values will have to be specified as strings always.
831 Each frame is passed with its timestamp from the demuxer to the muxer.
833 Frames will be duplicated and dropped to achieve exactly the requested
836 Frames are passed through with their timestamp or dropped so as to
837 prevent 2 frames from having the same timestamp.
839 As passthrough but destroys all timestamps, making the muxer generate
840 fresh timestamps based on frame-rate.
842 Chooses between 1 and 2 depending on muxer capabilities. This is the
846 With -map you can select from which stream the timestamps should be
847 taken. You can leave either video or audio unchanged and sync the
848 remaining stream(s) to the unchanged one.
850 @item -async @var{samples_per_second}
851 Audio sync method. "Stretches/squeezes" the audio stream to match the timestamps,
852 the parameter is the maximum samples per second by which the audio is changed.
853 -async 1 is a special case where only the start of the audio stream is corrected
854 without any later correction.
855 This option has been deprecated. Use the @code{aresample} audio filter instead.
858 Do not process input timestamps, but keep their values without trying
859 to sanitize them. In particular, do not remove the initial start time
862 Note that, depending on the @option{vsync} option or on specific muxer
863 processing, the output timestamps may mismatch with the input
864 timestamps even when this option is selected.
866 @item -copytb @var{mode}
867 Specify how to set the encoder timebase when stream copying. @var{mode} is an
868 integer numeric value, and can assume one of the following values:
872 Use the demuxer timebase.
874 The time base is copied to the output encoder from the corresponding input
875 demuxer. This is sometimes required to avoid non monotonically increasing
876 timestamps when copying video streams with variable frame rate.
879 Use the decoder timebase.
881 The time base is copied to the output encoder from the corresponding input
885 Try to make the choice automatically, in order to generate a sane output.
890 @item -shortest (@emph{output})
891 Finish encoding when the shortest input stream ends.
892 @item -dts_delta_threshold
893 Timestamp discontinuity delta threshold.
894 @item -muxdelay @var{seconds} (@emph{input})
895 Set the maximum demux-decode delay.
896 @item -muxpreload @var{seconds} (@emph{input})
897 Set the initial demux-decode delay.
898 @item -streamid @var{output-stream-index}:@var{new-value} (@emph{output})
899 Assign a new stream-id value to an output stream. This option should be
900 specified prior to the output filename to which it applies.
901 For the situation where multiple output files exist, a streamid
902 may be reassigned to a different value.
904 For example, to set the stream 0 PID to 33 and the stream 1 PID to 36 for
905 an output mpegts file:
907 ffmpeg -i infile -streamid 0:33 -streamid 1:36 out.ts
910 @item -bsf[:@var{stream_specifier}] @var{bitstream_filters} (@emph{output,per-stream})
911 Set bitstream filters for matching streams. @var{bitstream_filters} is
912 a comma-separated list of bitstream filters. Use the @code{-bsfs} option
913 to get the list of bitstream filters.
915 ffmpeg -i h264.mp4 -c:v copy -bsf:v h264_mp4toannexb -an out.h264
918 ffmpeg -i file.mov -an -vn -bsf:s mov2textsub -c:s copy -f rawvideo sub.txt
921 @item -tag[:@var{stream_specifier}] @var{codec_tag} (@emph{per-stream})
922 Force a tag/fourcc for matching streams.
924 @item -timecode @var{hh}:@var{mm}:@var{ss}SEP@var{ff}
925 Specify Timecode for writing. @var{SEP} is ':' for non drop timecode and ';'
928 ffmpeg -i input.mpg -timecode 01:02:03.04 -r 30000/1001 -s ntsc output.mpg
931 @item -filter_complex @var{filtergraph} (@emph{global})
932 Define a complex filter graph, i.e. one with arbitrary number of inputs and/or
933 outputs. For simple graphs -- those with one input and one output of the same
934 type -- see the @option{-filter} options. @var{filtergraph} is a description of
935 the filter graph, as described in the ``Filtergraph syntax'' section of the
936 ffmpeg-filters manual.
938 Input link labels must refer to input streams using the
939 @code{[file_index:stream_specifier]} syntax (i.e. the same as @option{-map}
940 uses). If @var{stream_specifier} matches multiple streams, the first one will be
941 used. An unlabeled input will be connected to the first unused input stream of
944 Output link labels are referred to with @option{-map}. Unlabeled outputs are
945 added to the first output file.
947 Note that with this option it is possible to use only lavfi sources without
950 For example, to overlay an image over video
952 ffmpeg -i video.mkv -i image.png -filter_complex '[0:v][1:v]overlay[out]' -map
955 Here @code{[0:v]} refers to the first video stream in the first input file,
956 which is linked to the first (main) input of the overlay filter. Similarly the
957 first video stream in the second input is linked to the second (overlay) input
960 Assuming there is only one video stream in each input file, we can omit input
961 labels, so the above is equivalent to
963 ffmpeg -i video.mkv -i image.png -filter_complex 'overlay[out]' -map
967 Furthermore we can omit the output label and the single output from the filter
968 graph will be added to the output file automatically, so we can simply write
970 ffmpeg -i video.mkv -i image.png -filter_complex 'overlay' out.mkv
973 To generate 5 seconds of pure red video using lavfi @code{color} source:
975 ffmpeg -filter_complex 'color=red' -t 5 out.mkv
979 As a special exception, you can use a bitmap subtitle stream as input: it
980 will be converted into a video with the same size as the largest video in
981 the file, or 720×576 if no video is present. Note that this is an
982 experimental and temporary solution. It will be removed once libavfilter has
983 proper support for subtitles.
985 For example, to hardcode subtitles on top of a DVB-T recording stored in
986 MPEG-TS format, delaying the subtitles by 1 second:
988 ffmpeg -i input.ts -filter_complex \
989 '[#0x2ef] setpts=PTS+1/TB [sub] ; [#0x2d0] [sub] overlay' \
990 -sn -map '#0x2dc' output.mkv
992 (0x2d0, 0x2dc and 0x2ef are the MPEG-TS PIDs of respectively the video,
993 audio and subtitles streams; 0:0, 0:3 and 0:7 would have worked too)
995 @section Preset files
996 A preset file contains a sequence of @var{option}=@var{value} pairs,
997 one for each line, specifying a sequence of options which would be
998 awkward to specify on the command line. Lines starting with the hash
999 ('#') character are ignored and are used to provide comments. Check
1000 the @file{presets} directory in the FFmpeg source tree for examples.
1002 Preset files are specified with the @code{vpre}, @code{apre},
1003 @code{spre}, and @code{fpre} options. The @code{fpre} option takes the
1004 filename of the preset instead of a preset name as input and can be
1005 used for any kind of codec. For the @code{vpre}, @code{apre}, and
1006 @code{spre} options, the options specified in a preset file are
1007 applied to the currently selected codec of the same type as the preset
1010 The argument passed to the @code{vpre}, @code{apre}, and @code{spre}
1011 preset options identifies the preset file to use according to the
1014 First ffmpeg searches for a file named @var{arg}.ffpreset in the
1015 directories @file{$FFMPEG_DATADIR} (if set), and @file{$HOME/.ffmpeg}, and in
1016 the datadir defined at configuration time (usually @file{PREFIX/share/ffmpeg})
1017 or in a @file{ffpresets} folder along the executable on win32,
1018 in that order. For example, if the argument is @code{libvpx-1080p}, it will
1019 search for the file @file{libvpx-1080p.ffpreset}.
1021 If no such file is found, then ffmpeg will search for a file named
1022 @var{codec_name}-@var{arg}.ffpreset in the above-mentioned
1023 directories, where @var{codec_name} is the name of the codec to which
1024 the preset file options will be applied. For example, if you select
1025 the video codec with @code{-vcodec libvpx} and use @code{-vpre 1080p},
1026 then it will search for the file @file{libvpx-1080p.ffpreset}.
1034 For streaming at very low bitrate application, use a low frame rate
1035 and a small GOP size. This is especially true for RealVideo where
1036 the Linux player does not seem to be very fast, so it can miss
1037 frames. An example is:
1040 ffmpeg -g 3 -r 3 -t 10 -b:v 50k -s qcif -f rv10 /tmp/b.rm
1044 The parameter 'q' which is displayed while encoding is the current
1045 quantizer. The value 1 indicates that a very good quality could
1046 be achieved. The value 31 indicates the worst quality. If q=31 appears
1047 too often, it means that the encoder cannot compress enough to meet
1048 your bitrate. You must either increase the bitrate, decrease the
1049 frame rate or decrease the frame size.
1052 If your computer is not fast enough, you can speed up the
1053 compression at the expense of the compression ratio. You can use
1054 '-me zero' to speed up motion estimation, and '-g 0' to disable
1055 motion estimation completely (you have only I-frames, which means it
1056 is about as good as JPEG compression).
1059 To have very low audio bitrates, reduce the sampling frequency
1060 (down to 22050 Hz for MPEG audio, 22050 or 11025 for AC-3).
1063 To have a constant quality (but a variable bitrate), use the option
1064 '-qscale n' when 'n' is between 1 (excellent quality) and 31 (worst
1071 @c man begin EXAMPLES
1073 @section Preset files
1075 A preset file contains a sequence of @var{option=value} pairs, one for
1076 each line, specifying a sequence of options which can be specified also on
1077 the command line. Lines starting with the hash ('#') character are ignored and
1078 are used to provide comments. Empty lines are also ignored. Check the
1079 @file{presets} directory in the FFmpeg source tree for examples.
1081 Preset files are specified with the @code{pre} option, this option takes a
1082 preset name as input. FFmpeg searches for a file named @var{preset_name}.avpreset in
1083 the directories @file{$AVCONV_DATADIR} (if set), and @file{$HOME/.ffmpeg}, and in
1084 the data directory defined at configuration time (usually @file{$PREFIX/share/ffmpeg})
1085 in that order. For example, if the argument is @code{libx264-max}, it will
1086 search for the file @file{libx264-max.avpreset}.
1088 @section Video and Audio grabbing
1090 If you specify the input format and device then ffmpeg can grab video
1094 ffmpeg -f oss -i /dev/dsp -f video4linux2 -i /dev/video0 /tmp/out.mpg
1097 Or with an ALSA audio source (mono input, card id 1) instead of OSS:
1099 ffmpeg -f alsa -ac 1 -i hw:1 -f video4linux2 -i /dev/video0 /tmp/out.mpg
1102 Note that you must activate the right video source and channel before
1103 launching ffmpeg with any TV viewer such as
1104 @uref{http://linux.bytesex.org/xawtv/, xawtv} by Gerd Knorr. You also
1105 have to set the audio recording levels correctly with a
1108 @section X11 grabbing
1110 Grab the X11 display with ffmpeg via
1113 ffmpeg -f x11grab -s cif -r 25 -i :0.0 /tmp/out.mpg
1116 0.0 is display.screen number of your X11 server, same as
1117 the DISPLAY environment variable.
1120 ffmpeg -f x11grab -s cif -r 25 -i :0.0+10,20 /tmp/out.mpg
1123 0.0 is display.screen number of your X11 server, same as the DISPLAY environment
1124 variable. 10 is the x-offset and 20 the y-offset for the grabbing.
1126 @section Video and Audio file format conversion
1128 Any supported file format and protocol can serve as input to ffmpeg:
1133 You can use YUV files as input:
1136 ffmpeg -i /tmp/test%d.Y /tmp/out.mpg
1139 It will use the files:
1141 /tmp/test0.Y, /tmp/test0.U, /tmp/test0.V,
1142 /tmp/test1.Y, /tmp/test1.U, /tmp/test1.V, etc...
1145 The Y files use twice the resolution of the U and V files. They are
1146 raw files, without header. They can be generated by all decent video
1147 decoders. You must specify the size of the image with the @option{-s} option
1148 if ffmpeg cannot guess it.
1151 You can input from a raw YUV420P file:
1154 ffmpeg -i /tmp/test.yuv /tmp/out.avi
1157 test.yuv is a file containing raw YUV planar data. Each frame is composed
1158 of the Y plane followed by the U and V planes at half vertical and
1159 horizontal resolution.
1162 You can output to a raw YUV420P file:
1165 ffmpeg -i mydivx.avi hugefile.yuv
1169 You can set several input files and output files:
1172 ffmpeg -i /tmp/a.wav -s 640x480 -i /tmp/a.yuv /tmp/a.mpg
1175 Converts the audio file a.wav and the raw YUV video file a.yuv
1179 You can also do audio and video conversions at the same time:
1182 ffmpeg -i /tmp/a.wav -ar 22050 /tmp/a.mp2
1185 Converts a.wav to MPEG audio at 22050 Hz sample rate.
1188 You can encode to several formats at the same time and define a
1189 mapping from input stream to output streams:
1192 ffmpeg -i /tmp/a.wav -map 0:a -b:a 64k /tmp/a.mp2 -map 0:a -b:a 128k /tmp/b.mp2
1195 Converts a.wav to a.mp2 at 64 kbits and to b.mp2 at 128 kbits. '-map
1196 file:index' specifies which input stream is used for each output
1197 stream, in the order of the definition of output streams.
1200 You can transcode decrypted VOBs:
1203 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
1206 This is a typical DVD ripping example; the input is a VOB file, the
1207 output an AVI file with MPEG-4 video and MP3 audio. Note that in this
1208 command we use B-frames so the MPEG-4 stream is DivX5 compatible, and
1209 GOP size is 300 which means one intra frame every 10 seconds for 29.97fps
1210 input video. Furthermore, the audio stream is MP3-encoded so you need
1211 to enable LAME support by passing @code{--enable-libmp3lame} to configure.
1212 The mapping is particularly useful for DVD transcoding
1213 to get the desired audio language.
1215 NOTE: To see the supported input formats, use @code{ffmpeg -formats}.
1218 You can extract images from a video, or create a video from many images:
1220 For extracting images from a video:
1222 ffmpeg -i foo.avi -r 1 -s WxH -f image2 foo-%03d.jpeg
1225 This will extract one video frame per second from the video and will
1226 output them in files named @file{foo-001.jpeg}, @file{foo-002.jpeg},
1227 etc. Images will be rescaled to fit the new WxH values.
1229 If you want to extract just a limited number of frames, you can use the
1230 above command in combination with the -vframes or -t option, or in
1231 combination with -ss to start extracting from a certain point in time.
1233 For creating a video from many images:
1235 ffmpeg -f image2 -i foo-%03d.jpeg -r 12 -s WxH foo.avi
1238 The syntax @code{foo-%03d.jpeg} specifies to use a decimal number
1239 composed of three digits padded with zeroes to express the sequence
1240 number. It is the same syntax supported by the C printf function, but
1241 only formats accepting a normal integer are suitable.
1243 When importing an image sequence, -i also supports expanding
1244 shell-like wildcard patterns (globbing) internally, by selecting the
1245 image2-specific @code{-pattern_type glob} option.
1247 For example, for creating a video from filenames matching the glob pattern
1250 ffmpeg -f image2 -pattern_type glob -i 'foo-*.jpeg' -r 12 -s WxH foo.avi
1254 You can put many streams of the same type in the output:
1257 ffmpeg -i test1.avi -i test2.avi -map 0:3 -map 0:2 -map 0:1 -map 0:0 -c copy test12.nut
1260 The resulting output file @file{test12.avi} will contain first four streams from
1261 the input file in reverse order.
1264 To force CBR video output:
1266 ffmpeg -i myfile.avi -b 4000k -minrate 4000k -maxrate 4000k -bufsize 1835k out.m2v
1270 The four options lmin, lmax, mblmin and mblmax use 'lambda' units,
1271 but you may use the QP2LAMBDA constant to easily convert from 'q' units:
1273 ffmpeg -i src.ext -lmax 21*QP2LAMBDA dst.ext
1282 @url{ffplay.html,ffplay}, @url{ffprobe.html,ffprobe}, @url{ffserver.html,ffserver},
1283 @url{ffmpeg-utils.html,ffmpeg-utils},
1284 @url{ffmpeg-scaler.html,ffmpeg-scaler},
1285 @url{ffmpeg-resampler.html,ffmpeg-resampler},
1286 @url{ffmpeg-codecs.html,ffmpeg-codecs},
1287 @url{ffmpeg-bitstream-filters,ffmpeg-bitstream-filters},
1288 @url{ffmpeg-formats.html,ffmpeg-formats},
1289 @url{ffmpeg-devices.html,ffmpeg-devices},
1290 @url{ffmpeg-protocols.html,ffmpeg-protocols},
1291 @url{ffmpeg-filters.html,ffmpeg-filters}
1295 ffplay(1), ffprobe(1), ffserver(1),
1296 ffmpeg-utils(1), ffmpeg-scaler(1), ffmpeg-resampler(1),
1297 ffmpeg-codecs(1), ffmpeg-bitstream-filters(1), ffmpeg-formats(1),
1298 ffmpeg-devices(1), ffmpeg-protocols(1), ffmpeg-filters(1)
1301 @include authors.texi
1306 @settitle ffmpeg video converter