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 Audio/Video grab options
626 @item -isync (@emph{global})
627 Synchronize read on input.
630 @section Advanced options
633 @item -map [-]@var{input_file_id}[:@var{stream_specifier}][,@var{sync_file_id}[:@var{stream_specifier}]] | @var{[linklabel]} (@emph{output})
635 Designate one or more input streams as a source for the output file. Each input
636 stream is identified by the input file index @var{input_file_id} and
637 the input stream index @var{input_stream_id} within the input
638 file. Both indices start at 0. If specified,
639 @var{sync_file_id}:@var{stream_specifier} sets which input stream
640 is used as a presentation sync reference.
642 The first @code{-map} option on the command line specifies the
643 source for output stream 0, the second @code{-map} option specifies
644 the source for output stream 1, etc.
646 A @code{-} character before the stream identifier creates a "negative" mapping.
647 It disables matching streams from already created mappings.
649 An alternative @var{[linklabel]} form will map outputs from complex filter
650 graphs (see the @option{-filter_complex} option) to the output file.
651 @var{linklabel} must correspond to a defined output link label in the graph.
653 For example, to map ALL streams from the first input file to output
655 ffmpeg -i INPUT -map 0 output
658 For example, if you have two audio streams in the first input file,
659 these streams are identified by "0:0" and "0:1". You can use
660 @code{-map} to select which streams to place in an output file. For
663 ffmpeg -i INPUT -map 0:1 out.wav
665 will map the input stream in @file{INPUT} identified by "0:1" to
666 the (single) output stream in @file{out.wav}.
668 For example, to select the stream with index 2 from input file
669 @file{a.mov} (specified by the identifier "0:2"), and stream with
670 index 6 from input @file{b.mov} (specified by the identifier "1:6"),
671 and copy them to the output file @file{out.mov}:
673 ffmpeg -i a.mov -i b.mov -c copy -map 0:2 -map 1:6 out.mov
676 To select all video and the third audio stream from an input file:
678 ffmpeg -i INPUT -map 0:v -map 0:a:2 OUTPUT
681 To map all the streams except the second audio, use negative mappings
683 ffmpeg -i INPUT -map 0 -map -0:a:1 OUTPUT
686 Note that using this option disables the default mappings for this output file.
688 @item -map_channel [@var{input_file_id}.@var{stream_specifier}.@var{channel_id}|-1][:@var{output_file_id}.@var{stream_specifier}]
689 Map an audio channel from a given input to an output. If
690 @var{output_file_id}.@var{stream_specifier} is not set, the audio channel will
691 be mapped on all the audio streams.
693 Using "-1" instead of
694 @var{input_file_id}.@var{stream_specifier}.@var{channel_id} will map a muted
697 For example, assuming @var{INPUT} is a stereo audio file, you can switch the
698 two audio channels with the following command:
700 ffmpeg -i INPUT -map_channel 0.0.1 -map_channel 0.0.0 OUTPUT
703 If you want to mute the first channel and keep the second:
705 ffmpeg -i INPUT -map_channel -1 -map_channel 0.0.1 OUTPUT
708 The order of the "-map_channel" option specifies the order of the channels in
709 the output stream. The output channel layout is guessed from the number of
710 channels mapped (mono if one "-map_channel", stereo if two, etc.). Using "-ac"
711 in combination of "-map_channel" makes the channel gain levels to be updated if
712 input and output channel layouts don't match (for instance two "-map_channel"
713 options and "-ac 6").
715 You can also extract each channel of an input to specific outputs; the following
716 command extracts two channels of the @var{INPUT} audio stream (file 0, stream 0)
717 to the respective @var{OUTPUT_CH0} and @var{OUTPUT_CH1} outputs:
719 ffmpeg -i INPUT -map_channel 0.0.0 OUTPUT_CH0 -map_channel 0.0.1 OUTPUT_CH1
722 The following example splits the channels of a stereo input into two separate
723 streams, which are put into the same output file:
725 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
728 Note that currently each output stream can only contain channels from a single
729 input stream; you can't for example use "-map_channel" to pick multiple input
730 audio channels contained in different streams (from the same or different files)
731 and merge them into a single output stream. It is therefore not currently
732 possible, for example, to turn two separate mono streams into a single stereo
733 stream. However splitting a stereo stream into two single channel mono streams
736 If you need this feature, a possible workaround is to use the @emph{amerge}
737 filter. For example, if you need to merge a media (here @file{input.mkv}) with 2
738 mono audio streams into one single stereo channel audio stream (and keep the
739 video stream), you can use the following command:
741 ffmpeg -i input.mkv -filter_complex "[0:1] [0:2] amerge" -c:a pcm_s16le -c:v copy output.mkv
744 @item -map_metadata[:@var{metadata_spec_out}] @var{infile}[:@var{metadata_spec_in}] (@emph{output,per-metadata})
745 Set metadata information of the next output file from @var{infile}. Note that
746 those are file indices (zero-based), not filenames.
747 Optional @var{metadata_spec_in/out} parameters specify, which metadata to copy.
748 A metadata specifier can have the following forms:
751 global metadata, i.e. metadata that applies to the whole file
753 @item @var{s}[:@var{stream_spec}]
754 per-stream metadata. @var{stream_spec} is a stream specifier as described
755 in the @ref{Stream specifiers} chapter. In an input metadata specifier, the first
756 matching stream is copied from. In an output metadata specifier, all matching
757 streams are copied to.
759 @item @var{c}:@var{chapter_index}
760 per-chapter metadata. @var{chapter_index} is the zero-based chapter index.
762 @item @var{p}:@var{program_index}
763 per-program metadata. @var{program_index} is the zero-based program index.
765 If metadata specifier is omitted, it defaults to global.
767 By default, global metadata is copied from the first input file,
768 per-stream and per-chapter metadata is copied along with streams/chapters. These
769 default mappings are disabled by creating any mapping of the relevant type. A negative
770 file index can be used to create a dummy mapping that just disables automatic copying.
772 For example to copy metadata from the first stream of the input file to global metadata
775 ffmpeg -i in.ogg -map_metadata 0:s:0 out.mp3
778 To do the reverse, i.e. copy global metadata to all audio streams:
780 ffmpeg -i in.mkv -map_metadata:s:a 0:g out.mkv
782 Note that simple @code{0} would work as well in this example, since global
783 metadata is assumed by default.
785 @item -map_chapters @var{input_file_index} (@emph{output})
786 Copy chapters from input file with index @var{input_file_index} to the next
787 output file. If no chapter mapping is specified, then chapters are copied from
788 the first input file with at least one chapter. Use a negative file index to
789 disable any chapter copying.
790 @item -debug @var{category}
791 Print specific debug info.
792 @var{category} is a number or a string containing one of the following values:
796 picture buffer allocations
804 memory management control operations (H.264)
811 per-block quantization parameter (QP)
819 visualize block types
821 visualize quantization parameter (QP), lower QP are tinted greener
823 @item -benchmark (@emph{global})
824 Show benchmarking information at the end of an encode.
825 Shows CPU time used and maximum memory consumption.
826 Maximum memory consumption is not supported on all systems,
827 it will usually display as 0 if not supported.
828 @item -benchmark_all (@emph{global})
829 Show benchmarking information during the encode.
830 Shows CPU time used in various steps (audio/video encode/decode).
831 @item -timelimit @var{duration} (@emph{global})
832 Exit after ffmpeg has been running for @var{duration} seconds.
833 @item -dump (@emph{global})
834 Dump each input packet to stderr.
835 @item -hex (@emph{global})
836 When dumping packets, also dump the payload.
837 @item -re (@emph{input})
838 Read input at native frame rate. Mainly used to simulate a grab device.
839 By default @command{ffmpeg} attempts to read the input(s) as fast as possible.
840 This option will slow down the reading of the input(s) to the native frame rate
841 of the input(s). It is useful for real-time output (e.g. live streaming). If
842 your input(s) is coming from some other live streaming source (through HTTP or
843 UDP for example) the server might already be in real-time, thus the option will
844 likely not be required. On the other hand, this is meaningful if your input(s)
845 is a file you are trying to push in real-time.
847 Loop over the input stream. Currently it works only for image
848 streams. This option is used for automatic FFserver testing.
849 This option is deprecated, use -loop 1.
850 @item -loop_output @var{number_of_times}
851 Repeatedly loop output for formats that support looping such as animated GIF
852 (0 will loop the output infinitely).
853 This option is deprecated, use -loop.
854 @item -vsync @var{parameter}
856 For compatibility reasons old values can be specified as numbers.
857 Newly added values will have to be specified as strings always.
861 Each frame is passed with its timestamp from the demuxer to the muxer.
863 Frames will be duplicated and dropped to achieve exactly the requested
866 Frames are passed through with their timestamp or dropped so as to
867 prevent 2 frames from having the same timestamp.
869 As passthrough but destroys all timestamps, making the muxer generate
870 fresh timestamps based on frame-rate.
872 Chooses between 1 and 2 depending on muxer capabilities. This is the
876 With -map you can select from which stream the timestamps should be
877 taken. You can leave either video or audio unchanged and sync the
878 remaining stream(s) to the unchanged one.
880 @item -async @var{samples_per_second}
881 Audio sync method. "Stretches/squeezes" the audio stream to match the timestamps,
882 the parameter is the maximum samples per second by which the audio is changed.
883 -async 1 is a special case where only the start of the audio stream is corrected
884 without any later correction.
885 This option has been deprecated. Use the @code{asyncts} audio filter instead.
887 Copy timestamps from input to output.
888 @item -copytb @var{mode}
889 Specify how to set the encoder timebase when stream copying. @var{mode} is an
890 integer numeric value, and can assume one of the following values:
894 Use the demuxer timebase.
896 The time base is copied to the output encoder from the corresponding input
897 demuxer. This is sometimes required to avoid non monotonically increasing
898 timestamps when copying video streams with variable frame rate.
901 Use the decoder timebase.
903 The time base is copied to the output encoder from the corresponding input
907 Try to make the choice automatically, in order to generate a sane output.
913 Finish encoding when the shortest input stream ends.
914 @item -dts_delta_threshold
915 Timestamp discontinuity delta threshold.
916 @item -muxdelay @var{seconds} (@emph{input})
917 Set the maximum demux-decode delay.
918 @item -muxpreload @var{seconds} (@emph{input})
919 Set the initial demux-decode delay.
920 @item -streamid @var{output-stream-index}:@var{new-value} (@emph{output})
921 Assign a new stream-id value to an output stream. This option should be
922 specified prior to the output filename to which it applies.
923 For the situation where multiple output files exist, a streamid
924 may be reassigned to a different value.
926 For example, to set the stream 0 PID to 33 and the stream 1 PID to 36 for
927 an output mpegts file:
929 ffmpeg -i infile -streamid 0:33 -streamid 1:36 out.ts
932 @item -bsf[:@var{stream_specifier}] @var{bitstream_filters} (@emph{output,per-stream})
933 Set bitstream filters for matching streams. @var{bistream_filters} is
934 a comma-separated list of bitstream filters. Use the @code{-bsfs} option
935 to get the list of bitstream filters.
937 ffmpeg -i h264.mp4 -c:v copy -bsf:v h264_mp4toannexb -an out.h264
940 ffmpeg -i file.mov -an -vn -bsf:s mov2textsub -c:s copy -f rawvideo sub.txt
943 @item -tag[:@var{stream_specifier}] @var{codec_tag} (@emph{per-stream})
944 Force a tag/fourcc for matching streams.
946 @item -timecode @var{hh}:@var{mm}:@var{ss}SEP@var{ff}
947 Specify Timecode for writing. @var{SEP} is ':' for non drop timecode and ';'
950 ffmpeg -i input.mpg -timecode 01:02:03.04 -r 30000/1001 -s ntsc output.mpg
953 @item -filter_complex @var{filtergraph} (@emph{global})
954 Define a complex filter graph, i.e. one with arbitrary number of inputs and/or
955 outputs. For simple graphs -- those with one input and one output of the same
956 type -- see the @option{-filter} options. @var{filtergraph} is a description of
957 the filter graph, as described in @ref{Filtergraph syntax}.
959 Input link labels must refer to input streams using the
960 @code{[file_index:stream_specifier]} syntax (i.e. the same as @option{-map}
961 uses). If @var{stream_specifier} matches multiple streams, the first one will be
962 used. An unlabeled input will be connected to the first unused input stream of
965 Output link labels are referred to with @option{-map}. Unlabeled outputs are
966 added to the first output file.
968 For example, to overlay an image over video
970 ffmpeg -i video.mkv -i image.png -filter_complex '[0:v][1:v]overlay[out]' -map
973 Here @code{[0:v]} refers to the first video stream in the first input file,
974 which is linked to the first (main) input of the overlay filter. Similarly the
975 first video stream in the second input is linked to the second (overlay) input
978 Assuming there is only one video stream in each input file, we can omit input
979 labels, so the above is equivalent to
981 ffmpeg -i video.mkv -i image.png -filter_complex 'overlay[out]' -map
985 Furthermore we can omit the output label and the single output from the filter
986 graph will be added to the output file automatically, so we can simply write
988 ffmpeg -i video.mkv -i image.png -filter_complex 'overlay' out.mkv
992 @section Preset files
993 A preset file contains a sequence of @var{option}=@var{value} pairs,
994 one for each line, specifying a sequence of options which would be
995 awkward to specify on the command line. Lines starting with the hash
996 ('#') character are ignored and are used to provide comments. Check
997 the @file{presets} directory in the FFmpeg source tree for examples.
999 Preset files are specified with the @code{vpre}, @code{apre},
1000 @code{spre}, and @code{fpre} options. The @code{fpre} option takes the
1001 filename of the preset instead of a preset name as input and can be
1002 used for any kind of codec. For the @code{vpre}, @code{apre}, and
1003 @code{spre} options, the options specified in a preset file are
1004 applied to the currently selected codec of the same type as the preset
1007 The argument passed to the @code{vpre}, @code{apre}, and @code{spre}
1008 preset options identifies the preset file to use according to the
1011 First ffmpeg searches for a file named @var{arg}.ffpreset in the
1012 directories @file{$FFMPEG_DATADIR} (if set), and @file{$HOME/.ffmpeg}, and in
1013 the datadir defined at configuration time (usually @file{PREFIX/share/ffmpeg})
1014 or in a @file{ffpresets} folder along the executable on win32,
1015 in that order. For example, if the argument is @code{libvpx-1080p}, it will
1016 search for the file @file{libvpx-1080p.ffpreset}.
1018 If no such file is found, then ffmpeg will search for a file named
1019 @var{codec_name}-@var{arg}.ffpreset in the above-mentioned
1020 directories, where @var{codec_name} is the name of the codec to which
1021 the preset file options will be applied. For example, if you select
1022 the video codec with @code{-vcodec libvpx} and use @code{-vpre 1080p},
1023 then it will search for the file @file{libvpx-1080p.ffpreset}.
1031 For streaming at very low bitrate application, use a low frame rate
1032 and a small GOP size. This is especially true for RealVideo where
1033 the Linux player does not seem to be very fast, so it can miss
1034 frames. An example is:
1037 ffmpeg -g 3 -r 3 -t 10 -b:v 50k -s qcif -f rv10 /tmp/b.rm
1041 The parameter 'q' which is displayed while encoding is the current
1042 quantizer. The value 1 indicates that a very good quality could
1043 be achieved. The value 31 indicates the worst quality. If q=31 appears
1044 too often, it means that the encoder cannot compress enough to meet
1045 your bitrate. You must either increase the bitrate, decrease the
1046 frame rate or decrease the frame size.
1049 If your computer is not fast enough, you can speed up the
1050 compression at the expense of the compression ratio. You can use
1051 '-me zero' to speed up motion estimation, and '-g 0' to disable
1052 motion estimation completely (you have only I-frames, which means it
1053 is about as good as JPEG compression).
1056 To have very low audio bitrates, reduce the sampling frequency
1057 (down to 22050 Hz for MPEG audio, 22050 or 11025 for AC-3).
1060 To have a constant quality (but a variable bitrate), use the option
1061 '-qscale n' when 'n' is between 1 (excellent quality) and 31 (worst
1068 @c man begin EXAMPLES
1070 @section Preset files
1072 A preset file contains a sequence of @var{option=value} pairs, one for
1073 each line, specifying a sequence of options which can be specified also on
1074 the command line. Lines starting with the hash ('#') character are ignored and
1075 are used to provide comments. Empty lines are also ignored. Check the
1076 @file{presets} directory in the FFmpeg source tree for examples.
1078 Preset files are specified with the @code{pre} option, this option takes a
1079 preset name as input. FFmpeg searches for a file named @var{preset_name}.avpreset in
1080 the directories @file{$AVCONV_DATADIR} (if set), and @file{$HOME/.ffmpeg}, and in
1081 the data directory defined at configuration time (usually @file{$PREFIX/share/ffmpeg})
1082 in that order. For example, if the argument is @code{libx264-max}, it will
1083 search for the file @file{libx264-max.avpreset}.
1085 @section Video and Audio grabbing
1087 If you specify the input format and device then ffmpeg can grab video
1091 ffmpeg -f oss -i /dev/dsp -f video4linux2 -i /dev/video0 /tmp/out.mpg
1094 Or with an ALSA audio source (mono input, card id 1) instead of OSS:
1096 ffmpeg -f alsa -ac 1 -i hw:1 -f video4linux2 -i /dev/video0 /tmp/out.mpg
1099 Note that you must activate the right video source and channel before
1100 launching ffmpeg with any TV viewer such as
1101 @uref{http://linux.bytesex.org/xawtv/, xawtv} by Gerd Knorr. You also
1102 have to set the audio recording levels correctly with a
1105 @section X11 grabbing
1107 Grab the X11 display with ffmpeg via
1110 ffmpeg -f x11grab -s cif -r 25 -i :0.0 /tmp/out.mpg
1113 0.0 is display.screen number of your X11 server, same as
1114 the DISPLAY environment variable.
1117 ffmpeg -f x11grab -s cif -r 25 -i :0.0+10,20 /tmp/out.mpg
1120 0.0 is display.screen number of your X11 server, same as the DISPLAY environment
1121 variable. 10 is the x-offset and 20 the y-offset for the grabbing.
1123 @section Video and Audio file format conversion
1125 Any supported file format and protocol can serve as input to ffmpeg:
1130 You can use YUV files as input:
1133 ffmpeg -i /tmp/test%d.Y /tmp/out.mpg
1136 It will use the files:
1138 /tmp/test0.Y, /tmp/test0.U, /tmp/test0.V,
1139 /tmp/test1.Y, /tmp/test1.U, /tmp/test1.V, etc...
1142 The Y files use twice the resolution of the U and V files. They are
1143 raw files, without header. They can be generated by all decent video
1144 decoders. You must specify the size of the image with the @option{-s} option
1145 if ffmpeg cannot guess it.
1148 You can input from a raw YUV420P file:
1151 ffmpeg -i /tmp/test.yuv /tmp/out.avi
1154 test.yuv is a file containing raw YUV planar data. Each frame is composed
1155 of the Y plane followed by the U and V planes at half vertical and
1156 horizontal resolution.
1159 You can output to a raw YUV420P file:
1162 ffmpeg -i mydivx.avi hugefile.yuv
1166 You can set several input files and output files:
1169 ffmpeg -i /tmp/a.wav -s 640x480 -i /tmp/a.yuv /tmp/a.mpg
1172 Converts the audio file a.wav and the raw YUV video file a.yuv
1176 You can also do audio and video conversions at the same time:
1179 ffmpeg -i /tmp/a.wav -ar 22050 /tmp/a.mp2
1182 Converts a.wav to MPEG audio at 22050 Hz sample rate.
1185 You can encode to several formats at the same time and define a
1186 mapping from input stream to output streams:
1189 ffmpeg -i /tmp/a.wav -map 0:a -b:a 64k /tmp/a.mp2 -map 0:a -b:a 128k /tmp/b.mp2
1192 Converts a.wav to a.mp2 at 64 kbits and to b.mp2 at 128 kbits. '-map
1193 file:index' specifies which input stream is used for each output
1194 stream, in the order of the definition of output streams.
1197 You can transcode decrypted VOBs:
1200 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
1203 This is a typical DVD ripping example; the input is a VOB file, the
1204 output an AVI file with MPEG-4 video and MP3 audio. Note that in this
1205 command we use B-frames so the MPEG-4 stream is DivX5 compatible, and
1206 GOP size is 300 which means one intra frame every 10 seconds for 29.97fps
1207 input video. Furthermore, the audio stream is MP3-encoded so you need
1208 to enable LAME support by passing @code{--enable-libmp3lame} to configure.
1209 The mapping is particularly useful for DVD transcoding
1210 to get the desired audio language.
1212 NOTE: To see the supported input formats, use @code{ffmpeg -formats}.
1215 You can extract images from a video, or create a video from many images:
1217 For extracting images from a video:
1219 ffmpeg -i foo.avi -r 1 -s WxH -f image2 foo-%03d.jpeg
1222 This will extract one video frame per second from the video and will
1223 output them in files named @file{foo-001.jpeg}, @file{foo-002.jpeg},
1224 etc. Images will be rescaled to fit the new WxH values.
1226 If you want to extract just a limited number of frames, you can use the
1227 above command in combination with the -vframes or -t option, or in
1228 combination with -ss to start extracting from a certain point in time.
1230 For creating a video from many images:
1232 ffmpeg -f image2 -i foo-%03d.jpeg -r 12 -s WxH foo.avi
1235 The syntax @code{foo-%03d.jpeg} specifies to use a decimal number
1236 composed of three digits padded with zeroes to express the sequence
1237 number. It is the same syntax supported by the C printf function, but
1238 only formats accepting a normal integer are suitable.
1240 When importing an image sequence, -i also supports expanding shell-like
1241 wildcard patterns (globbing) internally. To lower the chance of interfering
1242 with your actual file names and the shell's glob expansion, you are required
1243 to activate glob meta characters by prefixing them with a single @code{%}
1244 character, like in @code{foo-%*.jpeg}, @code{foo-%?%?%?.jpeg} or
1245 @code{foo-00%[234%]%*.jpeg}.
1246 If your filename actually contains a character sequence of a @code{%} character
1247 followed by a glob character, you must double the @code{%} character to escape
1248 it. Imagine your files begin with @code{%?-foo-}, then you could use a glob
1249 pattern like @code{%%?-foo-%*.jpeg}. For input patterns that could be both a
1250 printf or a glob pattern, ffmpeg will assume it is a glob pattern.
1253 You can put many streams of the same type in the output:
1256 ffmpeg -i test1.avi -i test2.avi -map 0.3 -map 0.2 -map 0.1 -map 0.0 -c copy test12.nut
1259 The resulting output file @file{test12.avi} will contain first four streams from
1260 the input file in reverse order.
1263 To force CBR video output:
1265 ffmpeg -i myfile.avi -b 4000k -minrate 4000k -maxrate 4000k -bufsize 1835k out.m2v
1269 The four options lmin, lmax, mblmin and mblmax use 'lambda' units,
1270 but you may use the QP2LAMBDA constant to easily convert from 'q' units:
1272 ffmpeg -i src.ext -lmax 21*QP2LAMBDA dst.ext
1278 @include syntax.texi
1280 @include decoders.texi
1281 @include encoders.texi
1282 @include demuxers.texi
1283 @include muxers.texi
1284 @include indevs.texi
1285 @include outdevs.texi
1286 @include protocols.texi
1287 @include bitstream_filters.texi
1288 @include filters.texi
1289 @include metadata.texi
1294 @settitle ffmpeg video converter
1296 @c man begin SEEALSO
1297 ffplay(1), ffprobe(1), ffserver(1) and the FFmpeg HTML documentation
1300 @c man begin AUTHORS