4 Muxers are configured elements in FFmpeg which allow writing
5 multimedia streams to a particular type of file.
7 When you configure your FFmpeg build, all the supported muxers
8 are enabled by default. You can list all available muxers using the
9 configure option @code{--list-muxers}.
11 You can disable all the muxers with the configure option
12 @code{--disable-muxers} and selectively enable / disable single muxers
13 with the options @code{--enable-muxer=@var{MUXER}} /
14 @code{--disable-muxer=@var{MUXER}}.
16 The option @code{-formats} of the ff* tools will display the list of
19 A description of some of the currently available muxers follows.
24 Audio Interchange File Format muxer.
26 It accepts the following options:
30 Enable ID3v2 tags writing when set to 1. Default is 0 (disabled).
33 Select ID3v2 version to write. Currently only version 3 and 4 (aka.
34 ID3v2.3 and ID3v2.4) are supported. The default is version 4.
41 CRC (Cyclic Redundancy Check) testing format.
43 This muxer computes and prints the Adler-32 CRC of all the input audio
44 and video frames. By default audio frames are converted to signed
45 16-bit raw audio and video frames to raw video before computing the
48 The output of the muxer consists of a single line of the form:
49 CRC=0x@var{CRC}, where @var{CRC} is a hexadecimal number 0-padded to
50 8 digits containing the CRC for all the decoded input frames.
52 For example to compute the CRC of the input, and store it in the file
55 ffmpeg -i INPUT -f crc out.crc
58 You can print the CRC to stdout with the command:
60 ffmpeg -i INPUT -f crc -
63 You can select the output format of each frame with @command{ffmpeg} by
64 specifying the audio and video codec and format. For example to
65 compute the CRC of the input audio converted to PCM unsigned 8-bit
66 and the input video converted to MPEG-2 video, use the command:
68 ffmpeg -i INPUT -c:a pcm_u8 -c:v mpeg2video -f crc -
71 See also the @ref{framecrc} muxer.
76 Per-packet CRC (Cyclic Redundancy Check) testing format.
78 This muxer computes and prints the Adler-32 CRC for each audio
79 and video packet. By default audio frames are converted to signed
80 16-bit raw audio and video frames to raw video before computing the
83 The output of the muxer consists of a line for each audio and video
86 @var{stream_index}, @var{packet_dts}, @var{packet_pts}, @var{packet_duration}, @var{packet_size}, 0x@var{CRC}
89 @var{CRC} is a hexadecimal number 0-padded to 8 digits containing the
92 For example to compute the CRC of the audio and video frames in
93 @file{INPUT}, converted to raw audio and video packets, and store it
94 in the file @file{out.crc}:
96 ffmpeg -i INPUT -f framecrc out.crc
99 To print the information to stdout, use the command:
101 ffmpeg -i INPUT -f framecrc -
104 With @command{ffmpeg}, you can select the output format to which the
105 audio and video frames are encoded before computing the CRC for each
106 packet by specifying the audio and video codec. For example, to
107 compute the CRC of each decoded input audio frame converted to PCM
108 unsigned 8-bit and of each decoded input video frame converted to
109 MPEG-2 video, use the command:
111 ffmpeg -i INPUT -c:a pcm_u8 -c:v mpeg2video -f framecrc -
114 See also the @ref{crc} muxer.
119 Per-packet MD5 testing format.
121 This muxer computes and prints the MD5 hash for each audio
122 and video packet. By default audio frames are converted to signed
123 16-bit raw audio and video frames to raw video before computing the
126 The output of the muxer consists of a line for each audio and video
129 @var{stream_index}, @var{packet_dts}, @var{packet_pts}, @var{packet_duration}, @var{packet_size}, @var{MD5}
132 @var{MD5} is a hexadecimal number representing the computed MD5 hash
135 For example to compute the MD5 of the audio and video frames in
136 @file{INPUT}, converted to raw audio and video packets, and store it
137 in the file @file{out.md5}:
139 ffmpeg -i INPUT -f framemd5 out.md5
142 To print the information to stdout, use the command:
144 ffmpeg -i INPUT -f framemd5 -
147 See also the @ref{md5} muxer.
152 Apple HTTP Live Streaming muxer that segments MPEG-TS according to
153 the HTTP Live Streaming specification.
155 It creates a playlist file and numbered segment files. The output
156 filename specifies the playlist filename; the segment filenames
157 receive the same basename as the playlist, a sequential number and
161 ffmpeg -i in.nut out.m3u8
165 @item -hls_time @var{seconds}
166 Set the segment length in seconds.
167 @item -hls_list_size @var{size}
168 Set the maximum number of playlist entries.
169 @item -hls_wrap @var{wrap}
170 Set the number after which index wraps.
171 @item -start_number @var{number}
172 Start the sequence from @var{number}.
180 Microsoft's icon file format (ICO) has some strict limitations that should be noted:
184 Size cannot exceed 256 pixels in any dimension
187 Only BMP and PNG images can be stored
190 If a BMP image is used, it must be one of the following pixel formats:
192 BMP Bit Depth FFmpeg Pixel Format
202 If a BMP image is used, it must use the BITMAPINFOHEADER DIB header
205 If a PNG image is used, it must use the rgba pixel format
213 The image file muxer writes video frames to image files.
215 The output filenames are specified by a pattern, which can be used to
216 produce sequentially numbered series of files.
217 The pattern may contain the string "%d" or "%0@var{N}d", this string
218 specifies the position of the characters representing a numbering in
219 the filenames. If the form "%0@var{N}d" is used, the string
220 representing the number in each filename is 0-padded to @var{N}
221 digits. The literal character '%' can be specified in the pattern with
224 If the pattern contains "%d" or "%0@var{N}d", the first filename of
225 the file list specified will contain the number 1, all the following
226 numbers will be sequential.
228 The pattern may contain a suffix which is used to automatically
229 determine the format of the image files to write.
231 For example the pattern "img-%03d.bmp" will specify a sequence of
232 filenames of the form @file{img-001.bmp}, @file{img-002.bmp}, ...,
233 @file{img-010.bmp}, etc.
234 The pattern "img%%-%d.jpg" will specify a sequence of filenames of the
235 form @file{img%-1.jpg}, @file{img%-2.jpg}, ..., @file{img%-10.jpg},
238 The following example shows how to use @command{ffmpeg} for creating a
239 sequence of files @file{img-001.jpeg}, @file{img-002.jpeg}, ...,
240 taking one image every second from the input video:
242 ffmpeg -i in.avi -vsync 1 -r 1 -f image2 'img-%03d.jpeg'
245 Note that with @command{ffmpeg}, if the format is not specified with the
246 @code{-f} option and the output filename specifies an image file
247 format, the image2 muxer is automatically selected, so the previous
248 command can be written as:
250 ffmpeg -i in.avi -vsync 1 -r 1 'img-%03d.jpeg'
253 Note also that the pattern must not necessarily contain "%d" or
254 "%0@var{N}d", for example to create a single image file
255 @file{img.jpeg} from the input video you can employ the command:
257 ffmpeg -i in.avi -f image2 -frames:v 1 img.jpeg
261 @item start_number @var{number}
262 Start the sequence from @var{number}. Default value is 1. Must be a
265 @item -update @var{number}
266 If @var{number} is nonzero, the filename will always be interpreted as just a
267 filename, not a pattern, and this file will be continuously overwritten with new
272 The image muxer supports the .Y.U.V image file format. This format is
273 special in that that each image frame consists of three files, for
274 each of the YUV420P components. To read or write this image file format,
275 specify the name of the '.Y' file. The muxer will automatically open the
276 '.U' and '.V' files as required.
280 Matroska container muxer.
282 This muxer implements the matroska and webm container specs.
284 The recognized metadata settings in this muxer are:
288 @item title=@var{title name}
289 Name provided to a single track
294 @item language=@var{language name}
295 Specifies the language of the track in the Matroska languages form
300 @item stereo_mode=@var{mode}
301 Stereo 3D video layout of two views in a single video track
306 Both views are arranged side by side, Left-eye view is on the left
308 Both views are arranged in top-bottom orientation, Left-eye view is at bottom
310 Both views are arranged in top-bottom orientation, Left-eye view is on top
311 @item checkerboard_rl
312 Each view is arranged in a checkerboard interleaved pattern, Left-eye view being first
313 @item checkerboard_lr
314 Each view is arranged in a checkerboard interleaved pattern, Right-eye view being first
315 @item row_interleaved_rl
316 Each view is constituted by a row based interleaving, Right-eye view is first row
317 @item row_interleaved_lr
318 Each view is constituted by a row based interleaving, Left-eye view is first row
319 @item col_interleaved_rl
320 Both views are arranged in a column based interleaving manner, Right-eye view is first column
321 @item col_interleaved_lr
322 Both views are arranged in a column based interleaving manner, Left-eye view is first column
323 @item anaglyph_cyan_red
324 All frames are in anaglyph format viewable through red-cyan filters
326 Both views are arranged side by side, Right-eye view is on the left
327 @item anaglyph_green_magenta
328 All frames are in anaglyph format viewable through green-magenta filters
330 Both eyes laced in one Block, Left-eye view is first
332 Both eyes laced in one Block, Right-eye view is first
336 For example a 3D WebM clip can be created using the following command line:
338 ffmpeg -i sample_left_right_clip.mpg -an -c:v libvpx -metadata stereo_mode=left_right -y stereo_clip.webm
341 This muxer supports the following options:
345 @item reserve_index_space
346 By default, this muxer writes the index for seeking (called cues in Matroska
347 terms) at the end of the file, because it cannot know in advance how much space
348 to leave for the index at the beginning of the file. However for some use cases
349 -- e.g. streaming where seeking is possible but slow -- it is useful to put the
350 index at the beginning of the file.
352 If this option is set to a non-zero value, the muxer will reserve a given amount
353 of space in the file header and then try to write the cues there when the muxing
354 finishes. If the available space does not suffice, muxing will fail. A safe size
355 for most use cases should be about 50kB per hour of video.
357 Note that cues are only written if the output is seekable and this option will
358 have no effect if it is not.
367 This muxer computes and prints the MD5 hash of all the input audio
368 and video frames. By default audio frames are converted to signed
369 16-bit raw audio and video frames to raw video before computing the
372 The output of the muxer consists of a single line of the form:
373 MD5=@var{MD5}, where @var{MD5} is a hexadecimal number representing
374 the computed MD5 hash.
376 For example to compute the MD5 hash of the input converted to raw
377 audio and video, and store it in the file @file{out.md5}:
379 ffmpeg -i INPUT -f md5 out.md5
382 You can print the MD5 to stdout with the command:
384 ffmpeg -i INPUT -f md5 -
387 See also the @ref{framemd5} muxer.
389 @section MOV/MP4/ISMV
391 The mov/mp4/ismv muxer supports fragmentation. Normally, a MOV/MP4
392 file has all the metadata about all packets stored in one location
393 (written at the end of the file, it can be moved to the start for
394 better playback by adding @var{faststart} to the @var{movflags}, or
395 using the @command{qt-faststart} tool). A fragmented
396 file consists of a number of fragments, where packets and metadata
397 about these packets are stored together. Writing a fragmented
398 file has the advantage that the file is decodable even if the
399 writing is interrupted (while a normal MOV/MP4 is undecodable if
400 it is not properly finished), and it requires less memory when writing
401 very long files (since writing normal MOV/MP4 files stores info about
402 every single packet in memory until the file is closed). The downside
403 is that it is less compatible with other applications.
405 Fragmentation is enabled by setting one of the AVOptions that define
406 how to cut the file into fragments:
409 @item -moov_size @var{bytes}
410 Reserves space for the moov atom at the beginning of the file instead of placing the
411 moov atom at the end. If the space reserved is insufficient, muxing will fail.
412 @item -movflags frag_keyframe
413 Start a new fragment at each video keyframe.
414 @item -frag_duration @var{duration}
415 Create fragments that are @var{duration} microseconds long.
416 @item -frag_size @var{size}
417 Create fragments that contain up to @var{size} bytes of payload data.
418 @item -movflags frag_custom
419 Allow the caller to manually choose when to cut fragments, by
420 calling @code{av_write_frame(ctx, NULL)} to write a fragment with
421 the packets written so far. (This is only useful with other
422 applications integrating libavformat, not from @command{ffmpeg}.)
423 @item -min_frag_duration @var{duration}
424 Don't create fragments that are shorter than @var{duration} microseconds long.
427 If more than one condition is specified, fragments are cut when
428 one of the specified conditions is fulfilled. The exception to this is
429 @code{-min_frag_duration}, which has to be fulfilled for any of the other
432 Additionally, the way the output file is written can be adjusted
433 through a few other options:
436 @item -movflags empty_moov
437 Write an initial moov atom directly at the start of the file, without
438 describing any samples in it. Generally, an mdat/moov pair is written
439 at the start of the file, as a normal MOV/MP4 file, containing only
440 a short portion of the file. With this option set, there is no initial
441 mdat atom, and the moov atom only describes the tracks but has
444 Files written with this option set do not work in QuickTime.
445 This option is implicitly set when writing ismv (Smooth Streaming) files.
446 @item -movflags separate_moof
447 Write a separate moof (movie fragment) atom for each track. Normally,
448 packets for all tracks are written in a moof atom (which is slightly
449 more efficient), but with this option set, the muxer writes one moof/mdat
450 pair for each track, making it easier to separate tracks.
452 This option is implicitly set when writing ismv (Smooth Streaming) files.
453 @item -movflags faststart
454 Run a second pass moving the index (moov atom) to the beginning of the file.
455 This operation can take a while, and will not work in various situations such
456 as fragmented output, thus it is not enabled by default.
457 @item -movflags rtphint
458 Add RTP hinting tracks to the output file.
461 Smooth Streaming content can be pushed in real time to a publishing
462 point on IIS with this muxer. Example:
464 ffmpeg -re @var{<normal input/transcoding options>} -movflags isml+frag_keyframe -f ismv http://server/publishingpoint.isml/Streams(Encoder1)
469 The MP3 muxer writes a raw MP3 stream with an ID3v2 header at the beginning and
470 optionally an ID3v1 tag at the end. ID3v2.3 and ID3v2.4 are supported, the
471 @code{id3v2_version} option controls which one is used. The legacy ID3v1 tag is
472 not written by default, but may be enabled with the @code{write_id3v1} option.
474 For seekable output the muxer also writes a Xing frame at the beginning, which
475 contains the number of frames in the file. It is useful for computing duration
478 The muxer supports writing ID3v2 attached pictures (APIC frames). The pictures
479 are supplied to the muxer in form of a video stream with a single packet. There
480 can be any number of those streams, each will correspond to a single APIC frame.
481 The stream metadata tags @var{title} and @var{comment} map to APIC
482 @var{description} and @var{picture type} respectively. See
483 @url{http://id3.org/id3v2.4.0-frames} for allowed picture types.
485 Note that the APIC frames must be written at the beginning, so the muxer will
486 buffer the audio frames until it gets all the pictures. It is therefore advised
487 to provide the pictures as soon as possible to avoid excessive buffering.
491 Write an mp3 with an ID3v2.3 header and an ID3v1 footer:
493 ffmpeg -i INPUT -id3v2_version 3 -write_id3v1 1 out.mp3
496 To attach a picture to an mp3 file select both the audio and the picture stream
499 ffmpeg -i input.mp3 -i cover.png -c copy -map 0 -map 1
500 -metadata:s:v title="Album cover" -metadata:s:v comment="Cover (Front)" out.mp3
505 MPEG transport stream muxer.
507 This muxer implements ISO 13818-1 and part of ETSI EN 300 468.
509 The muxer options are:
512 @item -mpegts_original_network_id @var{number}
513 Set the original_network_id (default 0x0001). This is unique identifier
514 of a network in DVB. Its main use is in the unique identification of a
515 service through the path Original_Network_ID, Transport_Stream_ID.
516 @item -mpegts_transport_stream_id @var{number}
517 Set the transport_stream_id (default 0x0001). This identifies a
519 @item -mpegts_service_id @var{number}
520 Set the service_id (default 0x0001) also known as program in DVB.
521 @item -mpegts_pmt_start_pid @var{number}
522 Set the first PID for PMT (default 0x1000, max 0x1f00).
523 @item -mpegts_start_pid @var{number}
524 Set the first PID for data packets (default 0x0100, max 0x0f00).
525 @item -mpegts_m2ts_mode @var{number}
526 Enable m2ts mode if set to 1. Default value is -1 which disables m2ts mode.
527 @item -muxrate @var{number}
529 @item -pes_payload_size @var{number}
530 Set minimum PES packet payload in bytes.
531 @item -mpegts_flags @var{flags}
532 Set flags (see below).
533 @item -mpegts_copyts @var{number}
534 Preserve original timestamps, if value is set to 1. Default value is -1, which
535 results in shifting timestamps so that they start from 0.
536 @item -tables_version @var{number}
537 Set PAT, PMT and SDT version (default 0, valid values are from 0 to 31, inclusively).
538 This option allows updating stream structure so that standard consumer may
539 detect the change. To do so, reopen output AVFormatContext (in case of API
540 usage) or restart ffmpeg instance, cyclically changing tables_version value:
542 ffmpeg -i source1.ts -codec copy -f mpegts -tables_version 0 udp://1.1.1.1:1111
543 ffmpeg -i source2.ts -codec copy -f mpegts -tables_version 1 udp://1.1.1.1:1111
545 ffmpeg -i source3.ts -codec copy -f mpegts -tables_version 31 udp://1.1.1.1:1111
546 ffmpeg -i source1.ts -codec copy -f mpegts -tables_version 0 udp://1.1.1.1:1111
547 ffmpeg -i source2.ts -codec copy -f mpegts -tables_version 1 udp://1.1.1.1:1111
552 Option mpegts_flags may take a set of such flags:
556 Reemit PAT/PMT before writing the next packet.
558 Use LATM packetization for AAC.
561 The recognized metadata settings in mpegts muxer are @code{service_provider}
562 and @code{service_name}. If they are not set the default for
563 @code{service_provider} is "FFmpeg" and the default for
564 @code{service_name} is "Service01".
567 ffmpeg -i file.mpg -c copy \
568 -mpegts_original_network_id 0x1122 \
569 -mpegts_transport_stream_id 0x3344 \
570 -mpegts_service_id 0x5566 \
571 -mpegts_pmt_start_pid 0x1500 \
572 -mpegts_start_pid 0x150 \
573 -metadata service_provider="Some provider" \
574 -metadata service_name="Some Channel" \
582 This muxer does not generate any output file, it is mainly useful for
583 testing or benchmarking purposes.
585 For example to benchmark decoding with @command{ffmpeg} you can use the
588 ffmpeg -benchmark -i INPUT -f null out.null
591 Note that the above command does not read or write the @file{out.null}
592 file, but specifying the output file is required by the @command{ffmpeg}
595 Alternatively you can write the command as:
597 ffmpeg -benchmark -i INPUT -f null -
605 @item -page_duration @var{duration}
606 Preferred page duration, in microseconds. The muxer will attempt to create
607 pages that are approximately @var{duration} microseconds long. This allows the
608 user to compromise between seek granularity and container overhead. The default
609 is 1 second. A value of 0 will fill all segments, making pages as large as
610 possible. A value of 1 will effectively use 1 packet-per-page in most
611 situations, giving a small seek granularity at the cost of additional container
615 @section segment, stream_segment, ssegment
617 Basic stream segmenter.
619 The segmenter muxer outputs streams to a number of separate files of nearly
620 fixed duration. Output filename pattern can be set in a fashion similar to
623 @code{stream_segment} is a variant of the muxer used to write to
624 streaming output formats, i.e. which do not require global headers,
625 and is recommended for outputting e.g. to MPEG transport stream segments.
626 @code{ssegment} is a shorter alias for @code{stream_segment}.
628 Every segment starts with a keyframe of the selected reference stream,
629 which is set through the @option{reference_stream} option.
631 Note that if you want accurate splitting for a video file, you need to
632 make the input key frames correspond to the exact splitting times
633 expected by the segmenter, or the segment muxer will start the new
634 segment with the key frame found next after the specified start
637 The segment muxer works best with a single constant frame rate video.
639 Optionally it can generate a list of the created segments, by setting
640 the option @var{segment_list}. The list type is specified by the
641 @var{segment_list_type} option.
643 The segment muxer supports the following options:
646 @item reference_stream @var{specifier}
647 Set the reference stream, as specified by the string @var{specifier}.
648 If @var{specifier} is set to @code{auto}, the reference is choosen
649 automatically. Otherwise it must be a stream specifier (see the ``Stream
650 specifiers'' chapter in the ffmpeg manual) which specifies the
651 reference stream. The default value is @code{auto}.
653 @item segment_format @var{format}
654 Override the inner container format, by default it is guessed by the filename
657 @item segment_list @var{name}
658 Generate also a listfile named @var{name}. If not specified no
659 listfile is generated.
661 @item segment_list_flags @var{flags}
662 Set flags affecting the segment list generation.
664 It currently supports the following flags:
667 Allow caching (only affects M3U8 list files).
670 Allow live-friendly file generation.
673 Default value is @code{samp}.
675 @item segment_list_size @var{size}
676 Update the list file so that it contains at most the last @var{size}
677 segments. If 0 the list file will contain all the segments. Default
680 @item segment_list_type @var{type}
681 Specify the format for the segment list file.
683 The following values are recognized:
686 Generate a flat list for the created segments, one segment per line.
689 Generate a list for the created segments, one segment per line,
690 each line matching the format (comma-separated values):
692 @var{segment_filename},@var{segment_start_time},@var{segment_end_time}
695 @var{segment_filename} is the name of the output file generated by the
696 muxer according to the provided pattern. CSV escaping (according to
697 RFC4180) is applied if required.
699 @var{segment_start_time} and @var{segment_end_time} specify
700 the segment start and end time expressed in seconds.
702 A list file with the suffix @code{".csv"} or @code{".ext"} will
703 auto-select this format.
705 @samp{ext} is deprecated in favor or @samp{csv}.
708 Generate an ffconcat file for the created segments. The resulting file
709 can be read using the FFmpeg @ref{concat} demuxer.
711 A list file with the suffix @code{".ffcat"} or @code{".ffconcat"} will
712 auto-select this format.
715 Generate an extended M3U8 file, version 3, compliant with
716 @url{http://tools.ietf.org/id/draft-pantos-http-live-streaming}.
718 A list file with the suffix @code{".m3u8"} will auto-select this format.
721 If not specified the type is guessed from the list file name suffix.
723 @item segment_time @var{time}
724 Set segment duration to @var{time}, the value must be a duration
725 specification. Default value is "2". See also the
726 @option{segment_times} option.
728 Note that splitting may not be accurate, unless you force the
729 reference stream key-frames at the given time. See the introductory
730 notice and the examples below.
732 @item segment_time_delta @var{delta}
733 Specify the accuracy time when selecting the start time for a
734 segment, expressed as a duration specification. Default value is "0".
736 When delta is specified a key-frame will start a new segment if its
737 PTS satisfies the relation:
739 PTS >= start_time - time_delta
742 This option is useful when splitting video content, which is always
743 split at GOP boundaries, in case a key frame is found just before the
744 specified split time.
746 In particular may be used in combination with the @file{ffmpeg} option
747 @var{force_key_frames}. The key frame times specified by
748 @var{force_key_frames} may not be set accurately because of rounding
749 issues, with the consequence that a key frame time may result set just
750 before the specified time. For constant frame rate videos a value of
751 1/2*@var{frame_rate} should address the worst case mismatch between
752 the specified time and the time set by @var{force_key_frames}.
754 @item segment_times @var{times}
755 Specify a list of split points. @var{times} contains a list of comma
756 separated duration specifications, in increasing order. See also
757 the @option{segment_time} option.
759 @item segment_frames @var{frames}
760 Specify a list of split video frame numbers. @var{frames} contains a
761 list of comma separated integer numbers, in increasing order.
763 This option specifies to start a new segment whenever a reference
764 stream key frame is found and the sequential number (starting from 0)
765 of the frame is greater or equal to the next value in the list.
767 @item segment_wrap @var{limit}
768 Wrap around segment index once it reaches @var{limit}.
770 @item segment_start_number @var{number}
771 Set the sequence number of the first segment. Defaults to @code{0}.
773 @item reset_timestamps @var{1|0}
774 Reset timestamps at the begin of each segment, so that each segment
775 will start with near-zero timestamps. It is meant to ease the playback
776 of the generated segments. May not work with some combinations of
777 muxers/codecs. It is set to @code{0} by default.
779 @item initial_offset @var{offset}
780 Specify timestamp offset to apply to the output packet timestamps. The
781 argument must be a time duration specification, and defaults to 0.
788 To remux the content of file @file{in.mkv} to a list of segments
789 @file{out-000.nut}, @file{out-001.nut}, etc., and write the list of
790 generated segments to @file{out.list}:
792 ffmpeg -i in.mkv -codec copy -map 0 -f segment -segment_list out.list out%03d.nut
796 As the example above, but segment the input file according to the split
797 points specified by the @var{segment_times} option:
799 ffmpeg -i in.mkv -codec copy -map 0 -f segment -segment_list out.csv -segment_times 1,2,3,5,8,13,21 out%03d.nut
803 As the example above, but use the @command{ffmpeg} @option{force_key_frames}
804 option to force key frames in the input at the specified location, together
805 with the segment option @option{segment_time_delta} to account for
806 possible roundings operated when setting key frame times.
808 ffmpeg -i in.mkv -force_key_frames 1,2,3,5,8,13,21 -codec:v mpeg4 -codec:a pcm_s16le -map 0 \
809 -f segment -segment_list out.csv -segment_times 1,2,3,5,8,13,21 -segment_time_delta 0.05 out%03d.nut
811 In order to force key frames on the input file, transcoding is
815 Segment the input file by splitting the input file according to the
816 frame numbers sequence specified with the @option{segment_frames} option:
818 ffmpeg -i in.mkv -codec copy -map 0 -f segment -segment_list out.csv -segment_frames 100,200,300,500,800 out%03d.nut
822 To convert the @file{in.mkv} to TS segments using the @code{libx264}
823 and @code{libfaac} encoders:
825 ffmpeg -i in.mkv -map 0 -codec:v libx264 -codec:a libfaac -f ssegment -segment_list out.list out%03d.ts
829 Segment the input file, and create an M3U8 live playlist (can be used
832 ffmpeg -re -i in.mkv -codec copy -map 0 -f segment -segment_list playlist.m3u8 \
833 -segment_list_flags +live -segment_time 10 out%03d.mkv
839 The tee muxer can be used to write the same data to several files or any
840 other kind of muxer. It can be used, for example, to both stream a video to
841 the network and save it to disk at the same time.
843 It is different from specifying several outputs to the @command{ffmpeg}
844 command-line tool because the audio and video data will be encoded only once
845 with the tee muxer; encoding can be a very expensive process. It is not
846 useful when using the libavformat API directly because it is then possible
847 to feed the same packets to several muxers directly.
849 The slave outputs are specified in the file name given to the muxer,
850 separated by '|'. If any of the slave name contains the '|' separator,
851 leading or trailing spaces or any special character, it must be
852 escaped (see the ``Quoting and escaping'' section in the ffmpeg-utils
855 Muxer options can be specified for each slave by prepending them as a list of
856 @var{key}=@var{value} pairs separated by ':', between square brackets. If
857 the options values contain a special character or the ':' separator, they
858 must be escaped; note that this is a second level escaping.
860 The following special options are also recognized:
863 Specify the format name. Useful if it cannot be guessed from the
866 @item bsfs[/@var{spec}]
867 Specify a list of bitstream filters to apply to the specified
868 output. It is possible to specify to which streams a given bitstream
869 filter applies, by appending a stream specifier to the option
870 separated by @code{/}. If the stream specifier is not specified, the
871 bistream filters will be applied to all streams in the output.
873 Several bitstream filters can be specified, separated by ",".
876 Select the streams that should be mapped to the slave output,
877 specified by a stream specifier. If not specified, this defaults to
878 all the input streams.
881 Some examples follow.
884 Encode something and both archive it in a WebM file and stream it
885 as MPEG-TS over UDP (the streams need to be explicitly mapped):
887 ffmpeg -i ... -c:v libx264 -c:a mp2 -f tee -map 0:v -map 0:a
888 "archive-20121107.mkv|[f=mpegts]udp://10.0.1.255:1234/"
892 Use @command{ffmpeg} to encode the input, and send the output
893 to three different destinations. The @code{dump_extra} bitstream
894 filter is used to add extradata information to all the output video
895 keyframes packets, as requested by the MPEG-TS format. The select
896 option is applied to @file{out.aac} in order to make it contain only
899 ffmpeg -i ... -map 0 -flags +global_header -c:v libx264 -c:a aac -strict experimental
900 -f tee "[bsfs/v=dump_extra]out.ts|[movflags=+faststart]out.mp4|[select=a]out.aac"
904 Note: some codecs may need different options depending on the output format;
905 the auto-detection of this can not work with the tee muxer. The main example
906 is the @option{global_header} flag.