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 -debug_ts (@emph{global})
357 Print timestamp information. It is off by default. This option is
358 mostly useful for testing and debugging purposes, and the output
359 format may change from one version to another, so it should not be
360 employed by portable scripts.
362 See also the option @code{-fdebug ts}.
364 @item -attach @var{filename} (@emph{output})
365 Add an attachment to the output file. This is supported by a few formats
366 like Matroska for e.g. fonts used in rendering subtitles. Attachments
367 are implemented as a specific type of stream, so this option will add
368 a new stream to the file. It is then possible to use per-stream options
369 on this stream in the usual way. Attachment streams created with this
370 option will be created after all the other streams (i.e. those created
371 with @code{-map} or automatic mappings).
373 Note that for Matroska you also have to set the mimetype metadata tag:
375 ffmpeg -i INPUT -attach DejaVuSans.ttf -metadata:s:2 mimetype=application/x-truetype-font out.mkv
377 (assuming that the attachment stream will be third in the output file).
379 @item -dump_attachment[:@var{stream_specifier}] @var{filename} (@emph{input,per-stream})
380 Extract the matching attachment stream into a file named @var{filename}. If
381 @var{filename} is empty, then the value of the @code{filename} metadata tag
384 E.g. to extract the first attachment to a file named 'out.ttf':
386 ffmpeg -dump_attachment:t:0 out.ttf INPUT
388 To extract all attachments to files determined by the @code{filename} tag:
390 ffmpeg -dump_attachment:t "" INPUT
393 Technical note -- attachments are implemented as codec extradata, so this
394 option can actually be used to extract extradata from any stream, not just
399 @section Video Options
402 @item -vframes @var{number} (@emph{output})
403 Set the number of video frames to record. This is an alias for @code{-frames:v}.
404 @item -r[:@var{stream_specifier}] @var{fps} (@emph{input/output,per-stream})
405 Set frame rate (Hz value, fraction or abbreviation).
407 As an input option, ignore any timestamps stored in the file and instead
408 generate timestamps assuming constant frame rate @var{fps}.
410 As an output option, duplicate or drop input frames to achieve constant output
411 frame rate @var{fps} (note that this actually causes the @code{fps} filter to be
412 inserted to the end of the corresponding filtergraph).
414 @item -s[:@var{stream_specifier}] @var{size} (@emph{input/output,per-stream})
417 As an input option, this is a shortcut for the @option{video_size} private
418 option, recognized by some demuxers for which the frame size is either not
419 stored in the file or is configurable -- e.g. raw video or video grabbers.
421 As an output option, this inserts the @code{scale} video filter to the
422 @emph{end} of the corresponding filtergraph. Please use the @code{scale} filter
423 directly to insert it at the beginning or some other place.
425 The format is @samp{wxh} (default - same as source).
427 @item -aspect[:@var{stream_specifier}] @var{aspect} (@emph{output,per-stream})
428 Set the video display aspect ratio specified by @var{aspect}.
430 @var{aspect} can be a floating point number string, or a string of the
431 form @var{num}:@var{den}, where @var{num} and @var{den} are the
432 numerator and denominator of the aspect ratio. For example "4:3",
433 "16:9", "1.3333", and "1.7777" are valid argument values.
435 @item -croptop @var{size}
436 @item -cropbottom @var{size}
437 @item -cropleft @var{size}
438 @item -cropright @var{size}
439 All the crop options have been removed. Use -vf
440 crop=width:height:x:y instead.
442 @item -padtop @var{size}
443 @item -padbottom @var{size}
444 @item -padleft @var{size}
445 @item -padright @var{size}
446 @item -padcolor @var{hex_color}
447 All the pad options have been removed. Use -vf
448 pad=width:height:x:y:color instead.
450 @item -vn (@emph{output})
451 Disable video recording.
453 @item -vcodec @var{codec} (@emph{output})
454 Set the video codec. This is an alias for @code{-codec:v}.
456 Use same quantizer as source (implies VBR).
458 Note that this is NOT SAME QUALITY. Do not use this option unless you know you
462 Select the pass number (1 or 2). It is used to do two-pass
463 video encoding. The statistics of the video are recorded in the first
464 pass into a log file (see also the option -passlogfile),
465 and in the second pass that log file is used to generate the video
466 at the exact requested bitrate.
467 On pass 1, you may just deactivate audio and set output to null,
468 examples for Windows and Unix:
470 ffmpeg -i foo.mov -c:v libxvid -pass 1 -an -f rawvideo -y NUL
471 ffmpeg -i foo.mov -c:v libxvid -pass 1 -an -f rawvideo -y /dev/null
474 @item -passlogfile @var{prefix} (@emph{global})
475 Set two-pass log file name prefix to @var{prefix}, the default file name
476 prefix is ``ffmpeg2pass''. The complete file name will be
477 @file{PREFIX-N.log}, where N is a number specific to the output
480 @item -vlang @var{code}
481 Set the ISO 639 language code (3 letters) of the current video stream.
483 @item -vf @var{filter_graph} (@emph{output})
484 @var{filter_graph} is a description of the filter graph to apply to
486 Use the option "-filters" to show all the available filters (including
487 also sources and sinks). This is an alias for @code{-filter:v}.
491 @section Advanced Video Options
494 @item -pix_fmt[:@var{stream_specifier}] @var{format} (@emph{input/output,per-stream})
495 Set pixel format. Use @code{-pix_fmts} to show all the supported
497 If the selected pixel format can not be selected, ffmpeg will print a
498 warning and select the best pixel format supported by the encoder.
499 If @var{pix_fmt} is prefixed by a @code{+}, ffmpeg will exit with an error
500 if the requested pixel format can not be selected, and automatic conversions
501 inside filter graphs are disabled.
502 If @var{pix_fmt} is a single @code{+}, ffmpeg selects the same pixel format
503 as the input (or graph output) and automatic conversions are disabled.
505 @item -sws_flags @var{flags} (@emph{input/output})
510 @item -rc_override[:@var{stream_specifier}] @var{override} (@emph{output,per-stream})
511 Rate control override for specific intervals, formatted as "int,int,int"
512 list separated with slashes. Two first values are the beginning and
513 end frame numbers, last one is quantizer to use if positive, or quality
517 Deinterlace pictures.
518 This option is deprecated since the deinterlacing is very low quality.
519 Use the yadif filter with @code{-filter:v yadif}.
521 Force interlacing support in encoder (MPEG-2 and MPEG-4 only).
522 Use this option if your input file is interlaced and you want
523 to keep the interlaced format for minimum losses.
524 The alternative is to deinterlace the input stream with
525 @option{-deinterlace}, but deinterlacing introduces losses.
527 Calculate PSNR of compressed frames.
529 Dump video coding statistics to @file{vstats_HHMMSS.log}.
530 @item -vstats_file @var{file}
531 Dump video coding statistics to @var{file}.
532 @item -top[:@var{stream_specifier}] @var{n} (@emph{output,per-stream})
533 top=1/bottom=0/auto=-1 field first
534 @item -dc @var{precision}
536 @item -vtag @var{fourcc/tag} (@emph{output})
537 Force video tag/fourcc. This is an alias for @code{-tag:v}.
538 @item -qphist (@emph{global})
540 @item -vbsf @var{bitstream_filter}
542 @item -force_key_frames[:@var{stream_specifier}] @var{time}[,@var{time}...] (@emph{output,per-stream})
543 Force key frames at the specified timestamps, more precisely at the first
544 frames after each specified time.
545 This option can be useful to ensure that a seek point is present at a
546 chapter mark or any other designated place in the output file.
547 The timestamps must be specified in ascending order.
549 @item -copyinkf[:@var{stream_specifier}] (@emph{output,per-stream})
550 When doing stream copy, copy also non-key frames found at the
554 @section Audio Options
557 @item -aframes @var{number} (@emph{output})
558 Set the number of audio frames to record. This is an alias for @code{-frames:a}.
559 @item -ar[:@var{stream_specifier}] @var{freq} (@emph{input/output,per-stream})
560 Set the audio sampling frequency. For output streams it is set by
561 default to the frequency of the corresponding input stream. For input
562 streams this option only makes sense for audio grabbing devices and raw
563 demuxers and is mapped to the corresponding demuxer options.
564 @item -aq @var{q} (@emph{output})
565 Set the audio quality (codec-specific, VBR). This is an alias for -q:a.
566 @item -ac[:@var{stream_specifier}] @var{channels} (@emph{input/output,per-stream})
567 Set the number of audio channels. For output streams it is set by
568 default to the number of input audio channels. For input streams
569 this option only makes sense for audio grabbing devices and raw demuxers
570 and is mapped to the corresponding demuxer options.
571 @item -an (@emph{output})
572 Disable audio recording.
573 @item -acodec @var{codec} (@emph{input/output})
574 Set the audio codec. This is an alias for @code{-codec:a}.
575 @item -sample_fmt[:@var{stream_specifier}] @var{sample_fmt} (@emph{output,per-stream})
576 Set the audio sample format. Use @code{-sample_fmts} to get a list
577 of supported sample formats.
578 @item -af @var{filter_graph} (@emph{output})
579 @var{filter_graph} is a description of the filter graph to apply to
581 Use the option "-filters" to show all the available filters (including
582 also sources and sinks). This is an alias for @code{-filter:a}.
585 @section Advanced Audio options:
588 @item -atag @var{fourcc/tag} (@emph{output})
589 Force audio tag/fourcc. This is an alias for @code{-tag:a}.
590 @item -absf @var{bitstream_filter}
594 @section Subtitle options:
597 @item -slang @var{code}
598 Set the ISO 639 language code (3 letters) of the current subtitle stream.
599 @item -scodec @var{codec} (@emph{input/output})
600 Set the subtitle codec. This is an alias for @code{-codec:s}.
601 @item -sn (@emph{output})
602 Disable subtitle recording.
603 @item -sbsf @var{bitstream_filter}
607 @section Audio/Video grab options
610 @item -isync (@emph{global})
611 Synchronize read on input.
614 @section Advanced options
617 @item -map [-]@var{input_file_id}[:@var{stream_specifier}][,@var{sync_file_id}[:@var{stream_specifier}]] | @var{[linklabel]} (@emph{output})
619 Designate one or more input streams as a source for the output file. Each input
620 stream is identified by the input file index @var{input_file_id} and
621 the input stream index @var{input_stream_id} within the input
622 file. Both indices start at 0. If specified,
623 @var{sync_file_id}:@var{stream_specifier} sets which input stream
624 is used as a presentation sync reference.
626 The first @code{-map} option on the command line specifies the
627 source for output stream 0, the second @code{-map} option specifies
628 the source for output stream 1, etc.
630 A @code{-} character before the stream identifier creates a "negative" mapping.
631 It disables matching streams from already created mappings.
633 An alternative @var{[linklabel]} form will map outputs from complex filter
634 graphs (see the @option{-filter_complex} option) to the output file.
635 @var{linklabel} must correspond to a defined output link label in the graph.
637 For example, to map ALL streams from the first input file to output
639 ffmpeg -i INPUT -map 0 output
642 For example, if you have two audio streams in the first input file,
643 these streams are identified by "0:0" and "0:1". You can use
644 @code{-map} to select which streams to place in an output file. For
647 ffmpeg -i INPUT -map 0:1 out.wav
649 will map the input stream in @file{INPUT} identified by "0:1" to
650 the (single) output stream in @file{out.wav}.
652 For example, to select the stream with index 2 from input file
653 @file{a.mov} (specified by the identifier "0:2"), and stream with
654 index 6 from input @file{b.mov} (specified by the identifier "1:6"),
655 and copy them to the output file @file{out.mov}:
657 ffmpeg -i a.mov -i b.mov -c copy -map 0:2 -map 1:6 out.mov
660 To select all video and the third audio stream from an input file:
662 ffmpeg -i INPUT -map 0:v -map 0:a:2 OUTPUT
665 To map all the streams except the second audio, use negative mappings
667 ffmpeg -i INPUT -map 0 -map -0:a:1 OUTPUT
670 Note that using this option disables the default mappings for this output file.
672 @item -map_channel [@var{input_file_id}.@var{stream_specifier}.@var{channel_id}|-1][:@var{output_file_id}.@var{stream_specifier}]
673 Map an audio channel from a given input to an output. If
674 @var{output_file_id}.@var{stream_specifier} is not set, the audio channel will
675 be mapped on all the audio streams.
677 Using "-1" instead of
678 @var{input_file_id}.@var{stream_specifier}.@var{channel_id} will map a muted
681 For example, assuming @var{INPUT} is a stereo audio file, you can switch the
682 two audio channels with the following command:
684 ffmpeg -i INPUT -map_channel 0.0.1 -map_channel 0.0.0 OUTPUT
687 If you want to mute the first channel and keep the second:
689 ffmpeg -i INPUT -map_channel -1 -map_channel 0.0.1 OUTPUT
692 The order of the "-map_channel" option specifies the order of the channels in
693 the output stream. The output channel layout is guessed from the number of
694 channels mapped (mono if one "-map_channel", stereo if two, etc.). Using "-ac"
695 in combination of "-map_channel" makes the channel gain levels to be updated if
696 input and output channel layouts don't match (for instance two "-map_channel"
697 options and "-ac 6").
699 You can also extract each channel of an input to specific outputs; the following
700 command extracts two channels of the @var{INPUT} audio stream (file 0, stream 0)
701 to the respective @var{OUTPUT_CH0} and @var{OUTPUT_CH1} outputs:
703 ffmpeg -i INPUT -map_channel 0.0.0 OUTPUT_CH0 -map_channel 0.0.1 OUTPUT_CH1
706 The following example splits the channels of a stereo input into two separate
707 streams, which are put into the same output file:
709 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
712 Note that currently each output stream can only contain channels from a single
713 input stream; you can't for example use "-map_channel" to pick multiple input
714 audio channels contained in different streams (from the same or different files)
715 and merge them into a single output stream. It is therefore not currently
716 possible, for example, to turn two separate mono streams into a single stereo
717 stream. However splitting a stereo stream into two single channel mono streams
720 If you need this feature, a possible workaround is to use the @emph{amerge}
721 filter. For example, if you need to merge a media (here @file{input.mkv}) with 2
722 mono audio streams into one single stereo channel audio stream (and keep the
723 video stream), you can use the following command:
725 ffmpeg -i input.mkv -filter_complex "[0:1] [0:2] amerge" -c:a pcm_s16le -c:v copy output.mkv
728 @item -map_metadata[:@var{metadata_spec_out}] @var{infile}[:@var{metadata_spec_in}] (@emph{output,per-metadata})
729 Set metadata information of the next output file from @var{infile}. Note that
730 those are file indices (zero-based), not filenames.
731 Optional @var{metadata_spec_in/out} parameters specify, which metadata to copy.
732 A metadata specifier can have the following forms:
735 global metadata, i.e. metadata that applies to the whole file
737 @item @var{s}[:@var{stream_spec}]
738 per-stream metadata. @var{stream_spec} is a stream specifier as described
739 in the @ref{Stream specifiers} chapter. In an input metadata specifier, the first
740 matching stream is copied from. In an output metadata specifier, all matching
741 streams are copied to.
743 @item @var{c}:@var{chapter_index}
744 per-chapter metadata. @var{chapter_index} is the zero-based chapter index.
746 @item @var{p}:@var{program_index}
747 per-program metadata. @var{program_index} is the zero-based program index.
749 If metadata specifier is omitted, it defaults to global.
751 By default, global metadata is copied from the first input file,
752 per-stream and per-chapter metadata is copied along with streams/chapters. These
753 default mappings are disabled by creating any mapping of the relevant type. A negative
754 file index can be used to create a dummy mapping that just disables automatic copying.
756 For example to copy metadata from the first stream of the input file to global metadata
759 ffmpeg -i in.ogg -map_metadata 0:s:0 out.mp3
762 To do the reverse, i.e. copy global metadata to all audio streams:
764 ffmpeg -i in.mkv -map_metadata:s:a 0:g out.mkv
766 Note that simple @code{0} would work as well in this example, since global
767 metadata is assumed by default.
769 @item -map_chapters @var{input_file_index} (@emph{output})
770 Copy chapters from input file with index @var{input_file_index} to the next
771 output file. If no chapter mapping is specified, then chapters are copied from
772 the first input file with at least one chapter. Use a negative file index to
773 disable any chapter copying.
774 @item -debug @var{category}
775 Print specific debug info.
776 @var{category} is a number or a string containing one of the following values:
780 picture buffer allocations
788 memory management control operations (H.264)
795 per-block quantization parameter (QP)
803 visualize block types
805 visualize quantization parameter (QP), lower QP are tinted greener
807 @item -benchmark (@emph{global})
808 Show benchmarking information at the end of an encode.
809 Shows CPU time used and maximum memory consumption.
810 Maximum memory consumption is not supported on all systems,
811 it will usually display as 0 if not supported.
812 @item -benchmark_all (@emph{global})
813 Show benchmarking information during the encode.
814 Shows CPU time used in various steps (audio/video encode/decode).
815 @item -timelimit @var{duration} (@emph{global})
816 Exit after ffmpeg has been running for @var{duration} seconds.
817 @item -dump (@emph{global})
818 Dump each input packet to stderr.
819 @item -hex (@emph{global})
820 When dumping packets, also dump the payload.
821 @item -re (@emph{input})
822 Read input at native frame rate. Mainly used to simulate a grab device.
824 Loop over the input stream. Currently it works only for image
825 streams. This option is used for automatic FFserver testing.
826 This option is deprecated, use -loop 1.
827 @item -loop_output @var{number_of_times}
828 Repeatedly loop output for formats that support looping such as animated GIF
829 (0 will loop the output infinitely).
830 This option is deprecated, use -loop.
831 @item -vsync @var{parameter}
833 For compatibility reasons old values can be specified as numbers.
834 Newly added values will have to be specified as strings always.
838 Each frame is passed with its timestamp from the demuxer to the muxer.
840 Frames will be duplicated and dropped to achieve exactly the requested
843 Frames are passed through with their timestamp or dropped so as to
844 prevent 2 frames from having the same timestamp.
846 As passthrough but destroys all timestamps, making the muxer generate
847 fresh timestamps based on frame-rate.
849 Chooses between 1 and 2 depending on muxer capabilities. This is the
853 With -map you can select from which stream the timestamps should be
854 taken. You can leave either video or audio unchanged and sync the
855 remaining stream(s) to the unchanged one.
857 @item -async @var{samples_per_second}
858 Audio sync method. "Stretches/squeezes" the audio stream to match the timestamps,
859 the parameter is the maximum samples per second by which the audio is changed.
860 -async 1 is a special case where only the start of the audio stream is corrected
861 without any later correction.
862 This option has been deprecated. Use the @code{asyncts} audio filter instead.
864 Copy timestamps from input to output.
865 @item -copytb @var{mode}
866 Specify how to set the encoder timebase when stream copying. @var{mode} is an
867 integer numeric value, and can assume one of the following values:
871 Use the demuxer timebase.
873 The time base is copied to the output encoder from the corresponding input
874 demuxer. This is sometimes required to avoid non monotonically increasing
875 timestamps when copying video streams with variable frame rate.
878 Use the decoder timebase.
880 The time base is copied to the output encoder from the corresponding input
884 Try to make the choice automatically, in order to generate a sane output.
890 Finish encoding when the shortest input stream ends.
891 @item -dts_delta_threshold
892 Timestamp discontinuity delta threshold.
893 @item -muxdelay @var{seconds} (@emph{input})
894 Set the maximum demux-decode delay.
895 @item -muxpreload @var{seconds} (@emph{input})
896 Set the initial demux-decode delay.
897 @item -streamid @var{output-stream-index}:@var{new-value} (@emph{output})
898 Assign a new stream-id value to an output stream. This option should be
899 specified prior to the output filename to which it applies.
900 For the situation where multiple output files exist, a streamid
901 may be reassigned to a different value.
903 For example, to set the stream 0 PID to 33 and the stream 1 PID to 36 for
904 an output mpegts file:
906 ffmpeg -i infile -streamid 0:33 -streamid 1:36 out.ts
909 @item -bsf[:@var{stream_specifier}] @var{bitstream_filters} (@emph{output,per-stream})
910 Set bitstream filters for matching streams. @var{bistream_filters} is
911 a comma-separated list of bitstream filters. Use the @code{-bsfs} option
912 to get the list of bitstream filters.
914 ffmpeg -i h264.mp4 -c:v copy -bsf:v h264_mp4toannexb -an out.h264
917 ffmpeg -i file.mov -an -vn -bsf:s mov2textsub -c:s copy -f rawvideo sub.txt
920 @item -tag[:@var{stream_specifier}] @var{codec_tag} (@emph{per-stream})
921 Force a tag/fourcc for matching streams.
923 @item -timecode @var{hh}:@var{mm}:@var{ss}SEP@var{ff}
924 Specify Timecode for writing. @var{SEP} is ':' for non drop timecode and ';'
927 ffmpeg -i input.mpg -timecode 01:02:03.04 -r 30000/1001 -s ntsc output.mpg
930 @item -filter_complex @var{filtergraph} (@emph{global})
931 Define a complex filter graph, i.e. one with arbitrary number of inputs and/or
932 outputs. For simple graphs -- those with one input and one output of the same
933 type -- see the @option{-filter} options. @var{filtergraph} is a description of
934 the filter graph, as described in @ref{Filtergraph syntax}.
936 Input link labels must refer to input streams using the
937 @code{[file_index:stream_specifier]} syntax (i.e. the same as @option{-map}
938 uses). If @var{stream_specifier} matches multiple streams, the first one will be
939 used. An unlabeled input will be connected to the first unused input stream of
942 Output link labels are referred to with @option{-map}. Unlabeled outputs are
943 added to the first output file.
945 For example, to overlay an image over video
947 ffmpeg -i video.mkv -i image.png -filter_complex '[0:v][1:v]overlay[out]' -map
950 Here @code{[0:v]} refers to the first video stream in the first input file,
951 which is linked to the first (main) input of the overlay filter. Similarly the
952 first video stream in the second input is linked to the second (overlay) input
955 Assuming there is only one video stream in each input file, we can omit input
956 labels, so the above is equivalent to
958 ffmpeg -i video.mkv -i image.png -filter_complex 'overlay[out]' -map
962 Furthermore we can omit the output label and the single output from the filter
963 graph will be added to the output file automatically, so we can simply write
965 ffmpeg -i video.mkv -i image.png -filter_complex 'overlay' out.mkv
969 @section Preset files
970 A preset file contains a sequence of @var{option}=@var{value} pairs,
971 one for each line, specifying a sequence of options which would be
972 awkward to specify on the command line. Lines starting with the hash
973 ('#') character are ignored and are used to provide comments. Check
974 the @file{presets} directory in the FFmpeg source tree for examples.
976 Preset files are specified with the @code{vpre}, @code{apre},
977 @code{spre}, and @code{fpre} options. The @code{fpre} option takes the
978 filename of the preset instead of a preset name as input and can be
979 used for any kind of codec. For the @code{vpre}, @code{apre}, and
980 @code{spre} options, the options specified in a preset file are
981 applied to the currently selected codec of the same type as the preset
984 The argument passed to the @code{vpre}, @code{apre}, and @code{spre}
985 preset options identifies the preset file to use according to the
988 First ffmpeg searches for a file named @var{arg}.ffpreset in the
989 directories @file{$FFMPEG_DATADIR} (if set), and @file{$HOME/.ffmpeg}, and in
990 the datadir defined at configuration time (usually @file{PREFIX/share/ffmpeg})
991 or in a @file{ffpresets} folder along the executable on win32,
992 in that order. For example, if the argument is @code{libvpx-1080p}, it will
993 search for the file @file{libvpx-1080p.ffpreset}.
995 If no such file is found, then ffmpeg will search for a file named
996 @var{codec_name}-@var{arg}.ffpreset in the above-mentioned
997 directories, where @var{codec_name} is the name of the codec to which
998 the preset file options will be applied. For example, if you select
999 the video codec with @code{-vcodec libvpx} and use @code{-vpre 1080p},
1000 then it will search for the file @file{libvpx-1080p.ffpreset}.
1008 For streaming at very low bitrate application, use a low frame rate
1009 and a small GOP size. This is especially true for RealVideo where
1010 the Linux player does not seem to be very fast, so it can miss
1011 frames. An example is:
1014 ffmpeg -g 3 -r 3 -t 10 -b:v 50k -s qcif -f rv10 /tmp/b.rm
1018 The parameter 'q' which is displayed while encoding is the current
1019 quantizer. The value 1 indicates that a very good quality could
1020 be achieved. The value 31 indicates the worst quality. If q=31 appears
1021 too often, it means that the encoder cannot compress enough to meet
1022 your bitrate. You must either increase the bitrate, decrease the
1023 frame rate or decrease the frame size.
1026 If your computer is not fast enough, you can speed up the
1027 compression at the expense of the compression ratio. You can use
1028 '-me zero' to speed up motion estimation, and '-g 0' to disable
1029 motion estimation completely (you have only I-frames, which means it
1030 is about as good as JPEG compression).
1033 To have very low audio bitrates, reduce the sampling frequency
1034 (down to 22050 Hz for MPEG audio, 22050 or 11025 for AC-3).
1037 To have a constant quality (but a variable bitrate), use the option
1038 '-qscale n' when 'n' is between 1 (excellent quality) and 31 (worst
1045 @c man begin EXAMPLES
1047 @section Preset files
1049 A preset file contains a sequence of @var{option=value} pairs, one for
1050 each line, specifying a sequence of options which can be specified also on
1051 the command line. Lines starting with the hash ('#') character are ignored and
1052 are used to provide comments. Empty lines are also ignored. Check the
1053 @file{presets} directory in the FFmpeg source tree for examples.
1055 Preset files are specified with the @code{pre} option, this option takes a
1056 preset name as input. FFmpeg searches for a file named @var{preset_name}.avpreset in
1057 the directories @file{$AVCONV_DATADIR} (if set), and @file{$HOME/.ffmpeg}, and in
1058 the data directory defined at configuration time (usually @file{$PREFIX/share/ffmpeg})
1059 in that order. For example, if the argument is @code{libx264-max}, it will
1060 search for the file @file{libx264-max.avpreset}.
1062 @section Video and Audio grabbing
1064 If you specify the input format and device then ffmpeg can grab video
1068 ffmpeg -f oss -i /dev/dsp -f video4linux2 -i /dev/video0 /tmp/out.mpg
1071 Or with an ALSA audio source (mono input, card id 1) instead of OSS:
1073 ffmpeg -f alsa -ac 1 -i hw:1 -f video4linux2 -i /dev/video0 /tmp/out.mpg
1076 Note that you must activate the right video source and channel before
1077 launching ffmpeg with any TV viewer such as
1078 @uref{http://linux.bytesex.org/xawtv/, xawtv} by Gerd Knorr. You also
1079 have to set the audio recording levels correctly with a
1082 @section X11 grabbing
1084 Grab the X11 display with ffmpeg via
1087 ffmpeg -f x11grab -s cif -r 25 -i :0.0 /tmp/out.mpg
1090 0.0 is display.screen number of your X11 server, same as
1091 the DISPLAY environment variable.
1094 ffmpeg -f x11grab -s cif -r 25 -i :0.0+10,20 /tmp/out.mpg
1097 0.0 is display.screen number of your X11 server, same as the DISPLAY environment
1098 variable. 10 is the x-offset and 20 the y-offset for the grabbing.
1100 @section Video and Audio file format conversion
1102 Any supported file format and protocol can serve as input to ffmpeg:
1107 You can use YUV files as input:
1110 ffmpeg -i /tmp/test%d.Y /tmp/out.mpg
1113 It will use the files:
1115 /tmp/test0.Y, /tmp/test0.U, /tmp/test0.V,
1116 /tmp/test1.Y, /tmp/test1.U, /tmp/test1.V, etc...
1119 The Y files use twice the resolution of the U and V files. They are
1120 raw files, without header. They can be generated by all decent video
1121 decoders. You must specify the size of the image with the @option{-s} option
1122 if ffmpeg cannot guess it.
1125 You can input from a raw YUV420P file:
1128 ffmpeg -i /tmp/test.yuv /tmp/out.avi
1131 test.yuv is a file containing raw YUV planar data. Each frame is composed
1132 of the Y plane followed by the U and V planes at half vertical and
1133 horizontal resolution.
1136 You can output to a raw YUV420P file:
1139 ffmpeg -i mydivx.avi hugefile.yuv
1143 You can set several input files and output files:
1146 ffmpeg -i /tmp/a.wav -s 640x480 -i /tmp/a.yuv /tmp/a.mpg
1149 Converts the audio file a.wav and the raw YUV video file a.yuv
1153 You can also do audio and video conversions at the same time:
1156 ffmpeg -i /tmp/a.wav -ar 22050 /tmp/a.mp2
1159 Converts a.wav to MPEG audio at 22050 Hz sample rate.
1162 You can encode to several formats at the same time and define a
1163 mapping from input stream to output streams:
1166 ffmpeg -i /tmp/a.wav -map 0:a -b:a 64k /tmp/a.mp2 -map 0:a -b:a 128k /tmp/b.mp2
1169 Converts a.wav to a.mp2 at 64 kbits and to b.mp2 at 128 kbits. '-map
1170 file:index' specifies which input stream is used for each output
1171 stream, in the order of the definition of output streams.
1174 You can transcode decrypted VOBs:
1177 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
1180 This is a typical DVD ripping example; the input is a VOB file, the
1181 output an AVI file with MPEG-4 video and MP3 audio. Note that in this
1182 command we use B-frames so the MPEG-4 stream is DivX5 compatible, and
1183 GOP size is 300 which means one intra frame every 10 seconds for 29.97fps
1184 input video. Furthermore, the audio stream is MP3-encoded so you need
1185 to enable LAME support by passing @code{--enable-libmp3lame} to configure.
1186 The mapping is particularly useful for DVD transcoding
1187 to get the desired audio language.
1189 NOTE: To see the supported input formats, use @code{ffmpeg -formats}.
1192 You can extract images from a video, or create a video from many images:
1194 For extracting images from a video:
1196 ffmpeg -i foo.avi -r 1 -s WxH -f image2 foo-%03d.jpeg
1199 This will extract one video frame per second from the video and will
1200 output them in files named @file{foo-001.jpeg}, @file{foo-002.jpeg},
1201 etc. Images will be rescaled to fit the new WxH values.
1203 If you want to extract just a limited number of frames, you can use the
1204 above command in combination with the -vframes or -t option, or in
1205 combination with -ss to start extracting from a certain point in time.
1207 For creating a video from many images:
1209 ffmpeg -f image2 -i foo-%03d.jpeg -r 12 -s WxH foo.avi
1212 The syntax @code{foo-%03d.jpeg} specifies to use a decimal number
1213 composed of three digits padded with zeroes to express the sequence
1214 number. It is the same syntax supported by the C printf function, but
1215 only formats accepting a normal integer are suitable.
1217 When importing an image sequence, -i also supports expanding shell-like
1218 wildcard patterns (globbing) internally. To lower the chance of interfering
1219 with your actual file names and the shell's glob expansion, you are required
1220 to activate glob meta characters by prefixing them with a single @code{%}
1221 character, like in @code{foo-%*.jpeg}, @code{foo-%?%?%?.jpeg} or
1222 @code{foo-00%[234%]%*.jpeg}.
1223 If your filename actually contains a character sequence of a @code{%} character
1224 followed by a glob character, you must double the @code{%} character to escape
1225 it. Imagine your files begin with @code{%?-foo-}, then you could use a glob
1226 pattern like @code{%%?-foo-%*.jpeg}. For input patterns that could be both a
1227 printf or a glob pattern, ffmpeg will assume it is a glob pattern.
1230 You can put many streams of the same type in the output:
1233 ffmpeg -i test1.avi -i test2.avi -map 0.3 -map 0.2 -map 0.1 -map 0.0 -c copy test12.nut
1236 The resulting output file @file{test12.avi} will contain first four streams from
1237 the input file in reverse order.
1240 To force CBR video output:
1242 ffmpeg -i myfile.avi -b 4000k -minrate 4000k -maxrate 4000k -bufsize 1835k out.m2v
1246 The four options lmin, lmax, mblmin and mblmax use 'lambda' units,
1247 but you may use the QP2LAMBDA constant to easily convert from 'q' units:
1249 ffmpeg -i src.ext -lmax 21*QP2LAMBDA dst.ext
1255 @include syntax.texi
1257 @include decoders.texi
1258 @include encoders.texi
1259 @include demuxers.texi
1260 @include muxers.texi
1261 @include indevs.texi
1262 @include outdevs.texi
1263 @include protocols.texi
1264 @include bitstream_filters.texi
1265 @include filters.texi
1266 @include metadata.texi
1271 @settitle ffmpeg video converter
1273 @c man begin SEEALSO
1274 ffplay(1), ffprobe(1), ffserver(1) and the FFmpeg HTML documentation
1277 @c man begin AUTHORS