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.
28 It accepts the following options:
32 Enable ID3v2 tags writing when set to 1. Default is 0 (disabled).
35 Select ID3v2 version to write. Currently only version 3 and 4 (aka.
36 ID3v2.3 and ID3v2.4) are supported. The default is version 4.
43 Advanced Systems Format muxer.
45 Note that Windows Media Audio (wma) and Windows Media Video (wmv) use this
50 It accepts the following options:
54 Set the muxer packet size. By tuning this setting you may reduce data
55 fragmentation or muxer overhead depending on your source. Default value is
56 3200, minimum is 100, maximum is 64k.
63 Chromaprint fingerprinter
65 This muxer feeds audio data to the Chromaprint library, which generates
66 a fingerprint for the provided audio data. It takes a single signed
67 native-endian 16-bit raw audio stream.
72 @item silence_threshold
73 Threshold for detecting silence, ranges from 0 to 32767. -1 for default
74 (required for use with the AcoustID service).
77 Algorithm index to fingerprint with.
80 Format to output the fingerprint as. Accepts the following options:
83 Binary raw fingerprint
86 Binary compressed fingerprint
89 Base64 compressed fingerprint
98 CRC (Cyclic Redundancy Check) testing format.
100 This muxer computes and prints the Adler-32 CRC of all the input audio
101 and video frames. By default audio frames are converted to signed
102 16-bit raw audio and video frames to raw video before computing the
105 The output of the muxer consists of a single line of the form:
106 CRC=0x@var{CRC}, where @var{CRC} is a hexadecimal number 0-padded to
107 8 digits containing the CRC for all the decoded input frames.
109 See also the @ref{framecrc} muxer.
113 For example to compute the CRC of the input, and store it in the file
116 ffmpeg -i INPUT -f crc out.crc
119 You can print the CRC to stdout with the command:
121 ffmpeg -i INPUT -f crc -
124 You can select the output format of each frame with @command{ffmpeg} by
125 specifying the audio and video codec and format. For example to
126 compute the CRC of the input audio converted to PCM unsigned 8-bit
127 and the input video converted to MPEG-2 video, use the command:
129 ffmpeg -i INPUT -c:a pcm_u8 -c:v mpeg2video -f crc -
135 Per-packet CRC (Cyclic Redundancy Check) testing format.
137 This muxer computes and prints the Adler-32 CRC for each audio
138 and video packet. By default audio frames are converted to signed
139 16-bit raw audio and video frames to raw video before computing the
142 The output of the muxer consists of a line for each audio and video
145 @var{stream_index}, @var{packet_dts}, @var{packet_pts}, @var{packet_duration}, @var{packet_size}, 0x@var{CRC}
148 @var{CRC} is a hexadecimal number 0-padded to 8 digits containing the
153 For example to compute the CRC of the audio and video frames in
154 @file{INPUT}, converted to raw audio and video packets, and store it
155 in the file @file{out.crc}:
157 ffmpeg -i INPUT -f framecrc out.crc
160 To print the information to stdout, use the command:
162 ffmpeg -i INPUT -f framecrc -
165 With @command{ffmpeg}, you can select the output format to which the
166 audio and video frames are encoded before computing the CRC for each
167 packet by specifying the audio and video codec. For example, to
168 compute the CRC of each decoded input audio frame converted to PCM
169 unsigned 8-bit and of each decoded input video frame converted to
170 MPEG-2 video, use the command:
172 ffmpeg -i INPUT -c:a pcm_u8 -c:v mpeg2video -f framecrc -
175 See also the @ref{crc} muxer.
180 Per-packet hash testing format.
182 This muxer computes and prints a cryptographic hash for each audio
183 and video packet. This can be used for packet-by-packet equality
184 checks without having to individually do a binary comparison on each.
186 By default audio frames are converted to signed 16-bit raw audio and
187 video frames to raw video before computing the hash, but the output
188 of explicit conversions to other codecs can also be used. It uses the
189 SHA-256 cryptographic hash function by default, but supports several
192 The output of the muxer consists of a line for each audio and video
195 @var{stream_index}, @var{packet_dts}, @var{packet_pts}, @var{packet_duration}, @var{packet_size}, @var{hash}
198 @var{hash} is a hexadecimal number representing the computed hash
202 @item hash @var{algorithm}
203 Use the cryptographic hash function specified by the string @var{algorithm}.
204 Supported values include @code{MD5}, @code{murmur3}, @code{RIPEMD128},
205 @code{RIPEMD160}, @code{RIPEMD256}, @code{RIPEMD320}, @code{SHA160},
206 @code{SHA224}, @code{SHA256} (default), @code{SHA512/224}, @code{SHA512/256},
207 @code{SHA384}, @code{SHA512}, @code{CRC32} and @code{adler32}.
213 To compute the SHA-256 hash of the audio and video frames in @file{INPUT},
214 converted to raw audio and video packets, and store it in the file
217 ffmpeg -i INPUT -f framehash out.sha256
220 To print the information to stdout, using the MD5 hash function, use
223 ffmpeg -i INPUT -f framehash -hash md5 -
226 See also the @ref{hash} muxer.
231 Per-packet MD5 testing format.
233 This is a variant of the @ref{framehash} muxer. Unlike that muxer,
234 it defaults to using the MD5 hash function.
238 To compute the MD5 hash of the audio and video frames in @file{INPUT},
239 converted to raw audio and video packets, and store it in the file
242 ffmpeg -i INPUT -f framemd5 out.md5
245 To print the information to stdout, use the command:
247 ffmpeg -i INPUT -f framemd5 -
250 See also the @ref{framehash} and @ref{md5} muxers.
257 It accepts the following options:
261 Set the number of times to loop the output. Use @code{-1} for no loop, @code{0}
262 for looping indefinitely (default).
265 Force the delay (expressed in centiseconds) after the last frame. Each frame
266 ends with a delay until the next frame. The default is @code{-1}, which is a
267 special value to tell the muxer to re-use the previous delay. In case of a
268 loop, you might want to customize this value to mark a pause for instance.
271 For example, to encode a gif looping 10 times, with a 5 seconds delay between
274 ffmpeg -i INPUT -loop 10 -final_delay 500 out.gif
277 Note 1: if you wish to extract the frames in separate GIF files, you need to
278 force the @ref{image2} muxer:
280 ffmpeg -i INPUT -c:v gif -f image2 "out%d.gif"
283 Note 2: the GIF format has a very small time base: the delay between two frames
284 can not be smaller than one centi second.
291 This muxer computes and prints a cryptographic hash of all the input
292 audio and video frames. This can be used for equality checks without
293 having to do a complete binary comparison.
295 By default audio frames are converted to signed 16-bit raw audio and
296 video frames to raw video before computing the hash, but the output
297 of explicit conversions to other codecs can also be used. Timestamps
298 are ignored. It uses the SHA-256 cryptographic hash function by default,
299 but supports several other algorithms.
301 The output of the muxer consists of a single line of the form:
302 @var{algo}=@var{hash}, where @var{algo} is a short string representing
303 the hash function used, and @var{hash} is a hexadecimal number
304 representing the computed hash.
307 @item hash @var{algorithm}
308 Use the cryptographic hash function specified by the string @var{algorithm}.
309 Supported values include @code{MD5}, @code{murmur3}, @code{RIPEMD128},
310 @code{RIPEMD160}, @code{RIPEMD256}, @code{RIPEMD320}, @code{SHA160},
311 @code{SHA224}, @code{SHA256} (default), @code{SHA512/224}, @code{SHA512/256},
312 @code{SHA384}, @code{SHA512}, @code{CRC32} and @code{adler32}.
318 To compute the SHA-256 hash of the input converted to raw audio and
319 video, and store it in the file @file{out.sha256}:
321 ffmpeg -i INPUT -f hash out.sha256
324 To print an MD5 hash to stdout use the command:
326 ffmpeg -i INPUT -f hash -hash md5 -
329 See also the @ref{framehash} muxer.
334 Apple HTTP Live Streaming muxer that segments MPEG-TS according to
335 the HTTP Live Streaming (HLS) specification.
337 It creates a playlist file, and one or more segment files. The output filename
338 specifies the playlist filename.
340 By default, the muxer creates a file for each segment produced. These files
341 have the same name as the playlist, followed by a sequential number and a
344 For example, to convert an input file with @command{ffmpeg}:
346 ffmpeg -i in.nut out.m3u8
348 This example will produce the playlist, @file{out.m3u8}, and segment files:
349 @file{out0.ts}, @file{out1.ts}, @file{out2.ts}, etc.
351 See also the @ref{segment} muxer, which provides a more generic and
352 flexible implementation of a segmenter, and can be used to perform HLS
357 This muxer supports the following options:
360 @item hls_time @var{seconds}
361 Set the target segment length in seconds. Default value is 2.
362 Segment will be cut on the next key frame after this time has passed.
364 @item hls_list_size @var{size}
365 Set the maximum number of playlist entries. If set to 0 the list file
366 will contain all the segments. Default value is 5.
368 @item hls_ts_options @var{options_list}
369 Set output format options using a :-separated list of key=value
370 parameters. Values containing @code{:} special characters must be
373 @item hls_wrap @var{wrap}
374 Set the number after which the segment filename number (the number
375 specified in each segment file) wraps. If set to 0 the number will be
376 never wrapped. Default value is 0.
378 This option is useful to avoid to fill the disk with many segment
379 files, and limits the maximum number of segment files written to disk
382 @item start_number @var{number}
383 Start the playlist sequence number from @var{number}. Default value is
386 @item hls_allow_cache @var{allowcache}
387 Explicitly set whether the client MAY (1) or MUST NOT (0) cache media segments.
389 @item hls_base_url @var{baseurl}
390 Append @var{baseurl} to every entry in the playlist.
391 Useful to generate playlists with absolute paths.
393 Note that the playlist sequence number must be unique for each segment
394 and it is not to be confused with the segment filename sequence number
395 which can be cyclic, for example if the @option{wrap} option is
398 @item hls_segment_filename @var{filename}
399 Set the segment filename. Unless hls_flags single_file is set @var{filename}
400 is used as a string format with the segment number:
402 ffmpeg in.nut -hls_segment_filename 'file%03d.ts' out.m3u8
404 This example will produce the playlist, @file{out.m3u8}, and segment files:
405 @file{file000.ts}, @file{file001.ts}, @file{file002.ts}, etc.
408 Use strftime on @var{filename} to expand the segment filename with localtime.
409 The segment number (%d) is not available in this mode.
411 ffmpeg in.nut -use_localtime 1 -hls_segment_filename 'file-%Y%m%d-%s.ts' out.m3u8
413 This example will produce the playlist, @file{out.m3u8}, and segment files:
414 @file{file-20160215-1455569023.ts}, @file{file-20160215-1455569024.ts}, etc.
416 @item use_localtime_mkdir
417 Used together with -use_localtime, it will create up to one subdirectory which
418 is expanded in @var{filename}.
420 ffmpeg in.nut -use_localtime 1 -use_localtime_mkdir 1 -hls_segment_filename '%Y%m%d/file-%Y%m%d-%s.ts' out.m3u8
422 This example will create a directory 201560215 (if it does not exist), and then
423 produce the playlist, @file{out.m3u8}, and segment files:
424 @file{201560215/file-20160215-1455569023.ts}, @file{201560215/file-20160215-1455569024.ts}, etc.
427 @item hls_key_info_file @var{key_info_file}
428 Use the information in @var{key_info_file} for segment encryption. The first
429 line of @var{key_info_file} specifies the key URI written to the playlist. The
430 key URL is used to access the encryption key during playback. The second line
431 specifies the path to the key file used to obtain the key during the encryption
432 process. The key file is read as a single packed array of 16 octets in binary
433 format. The optional third line specifies the initialization vector (IV) as a
434 hexadecimal string to be used instead of the segment sequence number (default)
435 for encryption. Changes to @var{key_info_file} will result in segment
436 encryption with the new key/IV and an entry in the playlist for the new key
439 Key info file format:
448 http://server/file.key
453 Example key file paths:
461 0123456789ABCDEF0123456789ABCDEF
464 Key info file example:
466 http://server/file.key
468 0123456789ABCDEF0123456789ABCDEF
471 Example shell script:
475 openssl rand 16 > file.key
476 echo $BASE_URL/file.key > file.keyinfo
477 echo file.key >> file.keyinfo
478 echo $(openssl rand -hex 16) >> file.keyinfo
479 ffmpeg -f lavfi -re -i testsrc -c:v h264 -hls_flags delete_segments \
480 -hls_key_info_file file.keyinfo out.m3u8
483 @item hls_flags single_file
484 If this flag is set, the muxer will store all segments in a single MPEG-TS
485 file, and will use byte ranges in the playlist. HLS playlists generated with
486 this way will have the version number 4.
489 ffmpeg -i in.nut -hls_flags single_file out.m3u8
491 Will produce the playlist, @file{out.m3u8}, and a single segment file,
494 @item hls_flags delete_segments
495 Segment files removed from the playlist are deleted after a period of time
496 equal to the duration of the segment plus the duration of the playlist.
498 @item hls_playlist_type event
499 Emit @code{#EXT-X-PLAYLIST-TYPE:EVENT} in the m3u8 header. Forces
500 @option{hls_list_size} to 0; the playlist can only be appended to.
502 @item hls_playlist_type vod
503 Emit @code{#EXT-X-PLAYLIST-TYPE:VOD} in the m3u8 header. Forces
504 @option{hls_list_size} to 0; the playlist must not change.
512 Microsoft's icon file format (ICO) has some strict limitations that should be noted:
516 Size cannot exceed 256 pixels in any dimension
519 Only BMP and PNG images can be stored
522 If a BMP image is used, it must be one of the following pixel formats:
524 BMP Bit Depth FFmpeg Pixel Format
534 If a BMP image is used, it must use the BITMAPINFOHEADER DIB header
537 If a PNG image is used, it must use the rgba pixel format
545 The image file muxer writes video frames to image files.
547 The output filenames are specified by a pattern, which can be used to
548 produce sequentially numbered series of files.
549 The pattern may contain the string "%d" or "%0@var{N}d", this string
550 specifies the position of the characters representing a numbering in
551 the filenames. If the form "%0@var{N}d" is used, the string
552 representing the number in each filename is 0-padded to @var{N}
553 digits. The literal character '%' can be specified in the pattern with
556 If the pattern contains "%d" or "%0@var{N}d", the first filename of
557 the file list specified will contain the number 1, all the following
558 numbers will be sequential.
560 The pattern may contain a suffix which is used to automatically
561 determine the format of the image files to write.
563 For example the pattern "img-%03d.bmp" will specify a sequence of
564 filenames of the form @file{img-001.bmp}, @file{img-002.bmp}, ...,
565 @file{img-010.bmp}, etc.
566 The pattern "img%%-%d.jpg" will specify a sequence of filenames of the
567 form @file{img%-1.jpg}, @file{img%-2.jpg}, ..., @file{img%-10.jpg},
572 The following example shows how to use @command{ffmpeg} for creating a
573 sequence of files @file{img-001.jpeg}, @file{img-002.jpeg}, ...,
574 taking one image every second from the input video:
576 ffmpeg -i in.avi -vsync 1 -r 1 -f image2 'img-%03d.jpeg'
579 Note that with @command{ffmpeg}, if the format is not specified with the
580 @code{-f} option and the output filename specifies an image file
581 format, the image2 muxer is automatically selected, so the previous
582 command can be written as:
584 ffmpeg -i in.avi -vsync 1 -r 1 'img-%03d.jpeg'
587 Note also that the pattern must not necessarily contain "%d" or
588 "%0@var{N}d", for example to create a single image file
589 @file{img.jpeg} from the input video you can employ the command:
591 ffmpeg -i in.avi -f image2 -frames:v 1 img.jpeg
594 The @option{strftime} option allows you to expand the filename with
595 date and time information. Check the documentation of
596 the @code{strftime()} function for the syntax.
598 For example to generate image files from the @code{strftime()}
599 "%Y-%m-%d_%H-%M-%S" pattern, the following @command{ffmpeg} command
602 ffmpeg -f v4l2 -r 1 -i /dev/video0 -f image2 -strftime 1 "%Y-%m-%d_%H-%M-%S.jpg"
609 Start the sequence from the specified number. Default value is 0.
612 If set to 1, the filename will always be interpreted as just a
613 filename, not a pattern, and the corresponding file will be continuously
614 overwritten with new images. Default value is 0.
617 If set to 1, expand the filename with date and time information from
618 @code{strftime()}. Default value is 0.
621 The image muxer supports the .Y.U.V image file format. This format is
622 special in that that each image frame consists of three files, for
623 each of the YUV420P components. To read or write this image file format,
624 specify the name of the '.Y' file. The muxer will automatically open the
625 '.U' and '.V' files as required.
629 Matroska container muxer.
631 This muxer implements the matroska and webm container specs.
635 The recognized metadata settings in this muxer are:
639 Set title name provided to a single track.
642 Specify the language of the track in the Matroska languages form.
644 The language can be either the 3 letters bibliographic ISO-639-2 (ISO
645 639-2/B) form (like "fre" for French), or a language code mixed with a
646 country code for specialities in languages (like "fre-ca" for Canadian
650 Set stereo 3D video layout of two views in a single video track.
652 The following values are recognized:
657 Both views are arranged side by side, Left-eye view is on the left
659 Both views are arranged in top-bottom orientation, Left-eye view is at bottom
661 Both views are arranged in top-bottom orientation, Left-eye view is on top
662 @item checkerboard_rl
663 Each view is arranged in a checkerboard interleaved pattern, Left-eye view being first
664 @item checkerboard_lr
665 Each view is arranged in a checkerboard interleaved pattern, Right-eye view being first
666 @item row_interleaved_rl
667 Each view is constituted by a row based interleaving, Right-eye view is first row
668 @item row_interleaved_lr
669 Each view is constituted by a row based interleaving, Left-eye view is first row
670 @item col_interleaved_rl
671 Both views are arranged in a column based interleaving manner, Right-eye view is first column
672 @item col_interleaved_lr
673 Both views are arranged in a column based interleaving manner, Left-eye view is first column
674 @item anaglyph_cyan_red
675 All frames are in anaglyph format viewable through red-cyan filters
677 Both views are arranged side by side, Right-eye view is on the left
678 @item anaglyph_green_magenta
679 All frames are in anaglyph format viewable through green-magenta filters
681 Both eyes laced in one Block, Left-eye view is first
683 Both eyes laced in one Block, Right-eye view is first
687 For example a 3D WebM clip can be created using the following command line:
689 ffmpeg -i sample_left_right_clip.mpg -an -c:v libvpx -metadata stereo_mode=left_right -y stereo_clip.webm
694 This muxer supports the following options:
697 @item reserve_index_space
698 By default, this muxer writes the index for seeking (called cues in Matroska
699 terms) at the end of the file, because it cannot know in advance how much space
700 to leave for the index at the beginning of the file. However for some use cases
701 -- e.g. streaming where seeking is possible but slow -- it is useful to put the
702 index at the beginning of the file.
704 If this option is set to a non-zero value, the muxer will reserve a given amount
705 of space in the file header and then try to write the cues there when the muxing
706 finishes. If the available space does not suffice, muxing will fail. A safe size
707 for most use cases should be about 50kB per hour of video.
709 Note that cues are only written if the output is seekable and this option will
710 have no effect if it is not.
718 This is a variant of the @ref{hash} muxer. Unlike that muxer, it
719 defaults to using the MD5 hash function.
723 To compute the MD5 hash of the input converted to raw
724 audio and video, and store it in the file @file{out.md5}:
726 ffmpeg -i INPUT -f md5 out.md5
729 You can print the MD5 to stdout with the command:
731 ffmpeg -i INPUT -f md5 -
734 See also the @ref{hash} and @ref{framemd5} muxers.
736 @section mov, mp4, ismv
738 MOV/MP4/ISMV (Smooth Streaming) muxer.
740 The mov/mp4/ismv muxer supports fragmentation. Normally, a MOV/MP4
741 file has all the metadata about all packets stored in one location
742 (written at the end of the file, it can be moved to the start for
743 better playback by adding @var{faststart} to the @var{movflags}, or
744 using the @command{qt-faststart} tool). A fragmented
745 file consists of a number of fragments, where packets and metadata
746 about these packets are stored together. Writing a fragmented
747 file has the advantage that the file is decodable even if the
748 writing is interrupted (while a normal MOV/MP4 is undecodable if
749 it is not properly finished), and it requires less memory when writing
750 very long files (since writing normal MOV/MP4 files stores info about
751 every single packet in memory until the file is closed). The downside
752 is that it is less compatible with other applications.
756 Fragmentation is enabled by setting one of the AVOptions that define
757 how to cut the file into fragments:
760 @item -moov_size @var{bytes}
761 Reserves space for the moov atom at the beginning of the file instead of placing the
762 moov atom at the end. If the space reserved is insufficient, muxing will fail.
763 @item -movflags frag_keyframe
764 Start a new fragment at each video keyframe.
765 @item -frag_duration @var{duration}
766 Create fragments that are @var{duration} microseconds long.
767 @item -frag_size @var{size}
768 Create fragments that contain up to @var{size} bytes of payload data.
769 @item -movflags frag_custom
770 Allow the caller to manually choose when to cut fragments, by
771 calling @code{av_write_frame(ctx, NULL)} to write a fragment with
772 the packets written so far. (This is only useful with other
773 applications integrating libavformat, not from @command{ffmpeg}.)
774 @item -min_frag_duration @var{duration}
775 Don't create fragments that are shorter than @var{duration} microseconds long.
778 If more than one condition is specified, fragments are cut when
779 one of the specified conditions is fulfilled. The exception to this is
780 @code{-min_frag_duration}, which has to be fulfilled for any of the other
783 Additionally, the way the output file is written can be adjusted
784 through a few other options:
787 @item -movflags empty_moov
788 Write an initial moov atom directly at the start of the file, without
789 describing any samples in it. Generally, an mdat/moov pair is written
790 at the start of the file, as a normal MOV/MP4 file, containing only
791 a short portion of the file. With this option set, there is no initial
792 mdat atom, and the moov atom only describes the tracks but has
795 This option is implicitly set when writing ismv (Smooth Streaming) files.
796 @item -movflags separate_moof
797 Write a separate moof (movie fragment) atom for each track. Normally,
798 packets for all tracks are written in a moof atom (which is slightly
799 more efficient), but with this option set, the muxer writes one moof/mdat
800 pair for each track, making it easier to separate tracks.
802 This option is implicitly set when writing ismv (Smooth Streaming) files.
803 @item -movflags faststart
804 Run a second pass moving the index (moov atom) to the beginning of the file.
805 This operation can take a while, and will not work in various situations such
806 as fragmented output, thus it is not enabled by default.
807 @item -movflags rtphint
808 Add RTP hinting tracks to the output file.
809 @item -movflags disable_chpl
810 Disable Nero chapter markers (chpl atom). Normally, both Nero chapters
811 and a QuickTime chapter track are written to the file. With this option
812 set, only the QuickTime chapter track will be written. Nero chapters can
813 cause failures when the file is reprocessed with certain tagging programs, like
814 mp3Tag 2.61a and iTunes 11.3, most likely other versions are affected as well.
815 @item -movflags omit_tfhd_offset
816 Do not write any absolute base_data_offset in tfhd atoms. This avoids
817 tying fragments to absolute byte positions in the file/streams.
818 @item -movflags default_base_moof
819 Similarly to the omit_tfhd_offset, this flag avoids writing the
820 absolute base_data_offset field in tfhd atoms, but does so by using
821 the new default-base-is-moof flag instead. This flag is new from
822 14496-12:2012. This may make the fragments easier to parse in certain
823 circumstances (avoiding basing track fragment location calculations
824 on the implicit end of the previous track fragment).
829 Smooth Streaming content can be pushed in real time to a publishing
830 point on IIS with this muxer. Example:
832 ffmpeg -re @var{<normal input/transcoding options>} -movflags isml+frag_keyframe -f ismv http://server/publishingpoint.isml/Streams(Encoder1)
835 @subsection Audible AAX
837 Audible AAX files are encrypted M4B files, and they can be decrypted by specifying a 4 byte activation secret.
839 ffmpeg -activation_bytes 1CEB00DA -i test.aax -vn -c:a copy output.mp4
844 The MP3 muxer writes a raw MP3 stream with the following optional features:
847 An ID3v2 metadata header at the beginning (enabled by default). Versions 2.3 and
848 2.4 are supported, the @code{id3v2_version} private option controls which one is
849 used (3 or 4). Setting @code{id3v2_version} to 0 disables the ID3v2 header
852 The muxer supports writing attached pictures (APIC frames) to the ID3v2 header.
853 The pictures are supplied to the muxer in form of a video stream with a single
854 packet. There can be any number of those streams, each will correspond to a
855 single APIC frame. The stream metadata tags @var{title} and @var{comment} map
856 to APIC @var{description} and @var{picture type} respectively. See
857 @url{http://id3.org/id3v2.4.0-frames} for allowed picture types.
859 Note that the APIC frames must be written at the beginning, so the muxer will
860 buffer the audio frames until it gets all the pictures. It is therefore advised
861 to provide the pictures as soon as possible to avoid excessive buffering.
864 A Xing/LAME frame right after the ID3v2 header (if present). It is enabled by
865 default, but will be written only if the output is seekable. The
866 @code{write_xing} private option can be used to disable it. The frame contains
867 various information that may be useful to the decoder, like the audio duration
871 A legacy ID3v1 tag at the end of the file (disabled by default). It may be
872 enabled with the @code{write_id3v1} private option, but as its capabilities are
873 very limited, its usage is not recommended.
878 Write an mp3 with an ID3v2.3 header and an ID3v1 footer:
880 ffmpeg -i INPUT -id3v2_version 3 -write_id3v1 1 out.mp3
883 To attach a picture to an mp3 file select both the audio and the picture stream
886 ffmpeg -i input.mp3 -i cover.png -c copy -map 0 -map 1
887 -metadata:s:v title="Album cover" -metadata:s:v comment="Cover (Front)" out.mp3
890 Write a "clean" MP3 without any extra features:
892 ffmpeg -i input.wav -write_xing 0 -id3v2_version 0 out.mp3
897 MPEG transport stream muxer.
899 This muxer implements ISO 13818-1 and part of ETSI EN 300 468.
901 The recognized metadata settings in mpegts muxer are @code{service_provider}
902 and @code{service_name}. If they are not set the default for
903 @code{service_provider} is "FFmpeg" and the default for
904 @code{service_name} is "Service01".
908 The muxer options are:
911 @item mpegts_original_network_id @var{number}
912 Set the original_network_id (default 0x0001). This is unique identifier
913 of a network in DVB. Its main use is in the unique identification of a
914 service through the path Original_Network_ID, Transport_Stream_ID.
915 @item mpegts_transport_stream_id @var{number}
916 Set the transport_stream_id (default 0x0001). This identifies a
918 @item mpegts_service_id @var{number}
919 Set the service_id (default 0x0001) also known as program in DVB.
920 @item mpegts_service_type @var{number}
921 Set the program service_type (default @var{digital_tv}), see below
922 a list of pre defined values.
923 @item mpegts_pmt_start_pid @var{number}
924 Set the first PID for PMT (default 0x1000, max 0x1f00).
925 @item mpegts_start_pid @var{number}
926 Set the first PID for data packets (default 0x0100, max 0x0f00).
927 @item mpegts_m2ts_mode @var{number}
928 Enable m2ts mode if set to 1. Default value is -1 which disables m2ts mode.
929 @item muxrate @var{number}
930 Set a constant muxrate (default VBR).
931 @item pcr_period @var{numer}
932 Override the default PCR retransmission time (default 20ms), ignored
933 if variable muxrate is selected.
934 @item pat_period @var{number}
935 Maximal time in seconds between PAT/PMT tables.
936 @item sdt_period @var{number}
937 Maximal time in seconds between SDT tables.
938 @item pes_payload_size @var{number}
939 Set minimum PES packet payload in bytes.
940 @item mpegts_flags @var{flags}
941 Set flags (see below).
942 @item mpegts_copyts @var{number}
943 Preserve original timestamps, if value is set to 1. Default value is -1, which
944 results in shifting timestamps so that they start from 0.
945 @item tables_version @var{number}
946 Set PAT, PMT and SDT version (default 0, valid values are from 0 to 31, inclusively).
947 This option allows updating stream structure so that standard consumer may
948 detect the change. To do so, reopen output AVFormatContext (in case of API
949 usage) or restart ffmpeg instance, cyclically changing tables_version value:
951 ffmpeg -i source1.ts -codec copy -f mpegts -tables_version 0 udp://1.1.1.1:1111
952 ffmpeg -i source2.ts -codec copy -f mpegts -tables_version 1 udp://1.1.1.1:1111
954 ffmpeg -i source3.ts -codec copy -f mpegts -tables_version 31 udp://1.1.1.1:1111
955 ffmpeg -i source1.ts -codec copy -f mpegts -tables_version 0 udp://1.1.1.1:1111
956 ffmpeg -i source2.ts -codec copy -f mpegts -tables_version 1 udp://1.1.1.1:1111
961 Option @option{mpegts_service_type} accepts the following values:
965 Any hexdecimal value between 0x01 to 0xff as defined in ETSI 300 468.
969 Digital Radio service.
972 @item advanced_codec_digital_radio
973 Advanced Codec Digital Radio service.
974 @item mpeg2_digital_hdtv
975 MPEG2 Digital HDTV service.
976 @item advanced_codec_digital_sdtv
977 Advanced Codec Digital SDTV service.
978 @item advanced_codec_digital_hdtv
979 Advanced Codec Digital HDTV service.
982 Option @option{mpegts_flags} may take a set of such flags:
986 Reemit PAT/PMT before writing the next packet.
988 Use LATM packetization for AAC.
989 @item pat_pmt_at_frames
990 Reemit PAT and PMT at each video frame.
992 Conform to System B (DVB) instead of System A (ATSC).
998 ffmpeg -i file.mpg -c copy \
999 -mpegts_original_network_id 0x1122 \
1000 -mpegts_transport_stream_id 0x3344 \
1001 -mpegts_service_id 0x5566 \
1002 -mpegts_pmt_start_pid 0x1500 \
1003 -mpegts_start_pid 0x150 \
1004 -metadata service_provider="Some provider" \
1005 -metadata service_name="Some Channel" \
1009 @section mxf, mxf_d10
1015 The muxer options are:
1018 @item store_user_comments @var{bool}
1019 Set if user comments should be stored if available or never.
1020 IRT D-10 does not allow user comments. The default is thus to write them for
1021 mxf but not for mxf_d10
1028 This muxer does not generate any output file, it is mainly useful for
1029 testing or benchmarking purposes.
1031 For example to benchmark decoding with @command{ffmpeg} you can use the
1034 ffmpeg -benchmark -i INPUT -f null out.null
1037 Note that the above command does not read or write the @file{out.null}
1038 file, but specifying the output file is required by the @command{ffmpeg}
1041 Alternatively you can write the command as:
1043 ffmpeg -benchmark -i INPUT -f null -
1049 @item -syncpoints @var{flags}
1050 Change the syncpoint usage in nut:
1052 @item @var{default} use the normal low-overhead seeking aids.
1053 @item @var{none} do not use the syncpoints at all, reducing the overhead but making the stream non-seekable;
1054 Use of this option is not recommended, as the resulting files are very damage
1055 sensitive and seeking is not possible. Also in general the overhead from
1056 syncpoints is negligible. Note, -@code{write_index} 0 can be used to disable
1057 all growing data tables, allowing to mux endless streams with limited memory
1058 and without these disadvantages.
1059 @item @var{timestamped} extend the syncpoint with a wallclock field.
1061 The @var{none} and @var{timestamped} flags are experimental.
1062 @item -write_index @var{bool}
1063 Write index at the end, the default is to write an index.
1067 ffmpeg -i INPUT -f_strict experimental -syncpoints none - | processor
1072 Ogg container muxer.
1075 @item -page_duration @var{duration}
1076 Preferred page duration, in microseconds. The muxer will attempt to create
1077 pages that are approximately @var{duration} microseconds long. This allows the
1078 user to compromise between seek granularity and container overhead. The default
1079 is 1 second. A value of 0 will fill all segments, making pages as large as
1080 possible. A value of 1 will effectively use 1 packet-per-page in most
1081 situations, giving a small seek granularity at the cost of additional container
1083 @item -serial_offset @var{value}
1084 Serial value from which to set the streams serial number.
1085 Setting it to different and sufficiently large values ensures that the produced
1086 ogg files can be safely chained.
1091 @section segment, stream_segment, ssegment
1093 Basic stream segmenter.
1095 This muxer outputs streams to a number of separate files of nearly
1096 fixed duration. Output filename pattern can be set in a fashion
1097 similar to @ref{image2}, or by using a @code{strftime} template if
1098 the @option{strftime} option is enabled.
1100 @code{stream_segment} is a variant of the muxer used to write to
1101 streaming output formats, i.e. which do not require global headers,
1102 and is recommended for outputting e.g. to MPEG transport stream segments.
1103 @code{ssegment} is a shorter alias for @code{stream_segment}.
1105 Every segment starts with a keyframe of the selected reference stream,
1106 which is set through the @option{reference_stream} option.
1108 Note that if you want accurate splitting for a video file, you need to
1109 make the input key frames correspond to the exact splitting times
1110 expected by the segmenter, or the segment muxer will start the new
1111 segment with the key frame found next after the specified start
1114 The segment muxer works best with a single constant frame rate video.
1116 Optionally it can generate a list of the created segments, by setting
1117 the option @var{segment_list}. The list type is specified by the
1118 @var{segment_list_type} option. The entry filenames in the segment
1119 list are set by default to the basename of the corresponding segment
1122 See also the @ref{hls} muxer, which provides a more specific
1123 implementation for HLS segmentation.
1127 The segment muxer supports the following options:
1130 @item increment_tc @var{1|0}
1131 if set to @code{1}, increment timecode between each segment
1132 If this is selected, the input need to have
1133 a timecode in the first video stream. Default value is
1136 @item reference_stream @var{specifier}
1137 Set the reference stream, as specified by the string @var{specifier}.
1138 If @var{specifier} is set to @code{auto}, the reference is chosen
1139 automatically. Otherwise it must be a stream specifier (see the ``Stream
1140 specifiers'' chapter in the ffmpeg manual) which specifies the
1141 reference stream. The default value is @code{auto}.
1143 @item segment_format @var{format}
1144 Override the inner container format, by default it is guessed by the filename
1147 @item segment_format_options @var{options_list}
1148 Set output format options using a :-separated list of key=value
1149 parameters. Values containing the @code{:} special character must be
1152 @item segment_list @var{name}
1153 Generate also a listfile named @var{name}. If not specified no
1154 listfile is generated.
1156 @item segment_list_flags @var{flags}
1157 Set flags affecting the segment list generation.
1159 It currently supports the following flags:
1162 Allow caching (only affects M3U8 list files).
1165 Allow live-friendly file generation.
1168 @item segment_list_size @var{size}
1169 Update the list file so that it contains at most @var{size}
1170 segments. If 0 the list file will contain all the segments. Default
1173 @item segment_list_entry_prefix @var{prefix}
1174 Prepend @var{prefix} to each entry. Useful to generate absolute paths.
1175 By default no prefix is applied.
1177 @item segment_list_type @var{type}
1178 Select the listing format.
1180 The following values are recognized:
1183 Generate a flat list for the created segments, one segment per line.
1186 Generate a list for the created segments, one segment per line,
1187 each line matching the format (comma-separated values):
1189 @var{segment_filename},@var{segment_start_time},@var{segment_end_time}
1192 @var{segment_filename} is the name of the output file generated by the
1193 muxer according to the provided pattern. CSV escaping (according to
1194 RFC4180) is applied if required.
1196 @var{segment_start_time} and @var{segment_end_time} specify
1197 the segment start and end time expressed in seconds.
1199 A list file with the suffix @code{".csv"} or @code{".ext"} will
1200 auto-select this format.
1202 @samp{ext} is deprecated in favor or @samp{csv}.
1205 Generate an ffconcat file for the created segments. The resulting file
1206 can be read using the FFmpeg @ref{concat} demuxer.
1208 A list file with the suffix @code{".ffcat"} or @code{".ffconcat"} will
1209 auto-select this format.
1212 Generate an extended M3U8 file, version 3, compliant with
1213 @url{http://tools.ietf.org/id/draft-pantos-http-live-streaming}.
1215 A list file with the suffix @code{".m3u8"} will auto-select this format.
1218 If not specified the type is guessed from the list file name suffix.
1220 @item segment_time @var{time}
1221 Set segment duration to @var{time}, the value must be a duration
1222 specification. Default value is "2". See also the
1223 @option{segment_times} option.
1225 Note that splitting may not be accurate, unless you force the
1226 reference stream key-frames at the given time. See the introductory
1227 notice and the examples below.
1229 @item segment_atclocktime @var{1|0}
1230 If set to "1" split at regular clock time intervals starting from 00:00
1231 o'clock. The @var{time} value specified in @option{segment_time} is
1232 used for setting the length of the splitting interval.
1234 For example with @option{segment_time} set to "900" this makes it possible
1235 to create files at 12:00 o'clock, 12:15, 12:30, etc.
1237 Default value is "0".
1239 @item segment_clocktime_offset @var{duration}
1240 Delay the segment splitting times with the specified duration when using
1241 @option{segment_atclocktime}.
1243 For example with @option{segment_time} set to "900" and
1244 @option{segment_clocktime_offset} set to "300" this makes it possible to
1245 create files at 12:05, 12:20, 12:35, etc.
1247 Default value is "0".
1249 @item segment_clocktime_wrap_duration @var{duration}
1250 Force the segmenter to only start a new segment if a packet reaches the muxer
1251 within the specified duration after the segmenting clock time. This way you
1252 can make the segmenter more resilient to backward local time jumps, such as
1253 leap seconds or transition to standard time from daylight savings time.
1255 Assuming that the delay between the packets of your source is less than 0.5
1256 second you can detect a leap second by specifying 0.5 as the duration.
1258 Default is the maximum possible duration which means starting a new segment
1259 regardless of the elapsed time since the last clock time.
1261 @item segment_time_delta @var{delta}
1262 Specify the accuracy time when selecting the start time for a
1263 segment, expressed as a duration specification. Default value is "0".
1265 When delta is specified a key-frame will start a new segment if its
1266 PTS satisfies the relation:
1268 PTS >= start_time - time_delta
1271 This option is useful when splitting video content, which is always
1272 split at GOP boundaries, in case a key frame is found just before the
1273 specified split time.
1275 In particular may be used in combination with the @file{ffmpeg} option
1276 @var{force_key_frames}. The key frame times specified by
1277 @var{force_key_frames} may not be set accurately because of rounding
1278 issues, with the consequence that a key frame time may result set just
1279 before the specified time. For constant frame rate videos a value of
1280 1/(2*@var{frame_rate}) should address the worst case mismatch between
1281 the specified time and the time set by @var{force_key_frames}.
1283 @item segment_times @var{times}
1284 Specify a list of split points. @var{times} contains a list of comma
1285 separated duration specifications, in increasing order. See also
1286 the @option{segment_time} option.
1288 @item segment_frames @var{frames}
1289 Specify a list of split video frame numbers. @var{frames} contains a
1290 list of comma separated integer numbers, in increasing order.
1292 This option specifies to start a new segment whenever a reference
1293 stream key frame is found and the sequential number (starting from 0)
1294 of the frame is greater or equal to the next value in the list.
1296 @item segment_wrap @var{limit}
1297 Wrap around segment index once it reaches @var{limit}.
1299 @item segment_start_number @var{number}
1300 Set the sequence number of the first segment. Defaults to @code{0}.
1302 @item strftime @var{1|0}
1303 Use the @code{strftime} function to define the name of the new
1304 segments to write. If this is selected, the output segment name must
1305 contain a @code{strftime} function template. Default value is
1308 @item break_non_keyframes @var{1|0}
1309 If enabled, allow segments to start on frames other than keyframes. This
1310 improves behavior on some players when the time between keyframes is
1311 inconsistent, but may make things worse on others, and can cause some oddities
1312 during seeking. Defaults to @code{0}.
1314 @item reset_timestamps @var{1|0}
1315 Reset timestamps at the begin of each segment, so that each segment
1316 will start with near-zero timestamps. It is meant to ease the playback
1317 of the generated segments. May not work with some combinations of
1318 muxers/codecs. It is set to @code{0} by default.
1320 @item initial_offset @var{offset}
1321 Specify timestamp offset to apply to the output packet timestamps. The
1322 argument must be a time duration specification, and defaults to 0.
1324 @item write_empty_segments @var{1|0}
1325 If enabled, write an empty segment if there are no packets during the period a
1326 segment would usually span. Otherwise, the segment will be filled with the next
1327 packet written. Defaults to @code{0}.
1330 @subsection Examples
1334 Remux the content of file @file{in.mkv} to a list of segments
1335 @file{out-000.nut}, @file{out-001.nut}, etc., and write the list of
1336 generated segments to @file{out.list}:
1338 ffmpeg -i in.mkv -codec copy -map 0 -f segment -segment_list out.list out%03d.nut
1342 Segment input and set output format options for the output segments:
1344 ffmpeg -i in.mkv -f segment -segment_time 10 -segment_format_options movflags=+faststart out%03d.mp4
1348 Segment the input file according to the split points specified by the
1349 @var{segment_times} option:
1351 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
1355 Use the @command{ffmpeg} @option{force_key_frames}
1356 option to force key frames in the input at the specified location, together
1357 with the segment option @option{segment_time_delta} to account for
1358 possible roundings operated when setting key frame times.
1360 ffmpeg -i in.mkv -force_key_frames 1,2,3,5,8,13,21 -codec:v mpeg4 -codec:a pcm_s16le -map 0 \
1361 -f segment -segment_list out.csv -segment_times 1,2,3,5,8,13,21 -segment_time_delta 0.05 out%03d.nut
1363 In order to force key frames on the input file, transcoding is
1367 Segment the input file by splitting the input file according to the
1368 frame numbers sequence specified with the @option{segment_frames} option:
1370 ffmpeg -i in.mkv -codec copy -map 0 -f segment -segment_list out.csv -segment_frames 100,200,300,500,800 out%03d.nut
1374 Convert the @file{in.mkv} to TS segments using the @code{libx264}
1375 and @code{libfaac} encoders:
1377 ffmpeg -i in.mkv -map 0 -codec:v libx264 -codec:a libfaac -f ssegment -segment_list out.list out%03d.ts
1381 Segment the input file, and create an M3U8 live playlist (can be used
1382 as live HLS source):
1384 ffmpeg -re -i in.mkv -codec copy -map 0 -f segment -segment_list playlist.m3u8 \
1385 -segment_list_flags +live -segment_time 10 out%03d.mkv
1389 @section smoothstreaming
1391 Smooth Streaming muxer generates a set of files (Manifest, chunks) suitable for serving with conventional web server.
1395 Specify the number of fragments kept in the manifest. Default 0 (keep all).
1397 @item extra_window_size
1398 Specify the number of fragments kept outside of the manifest before removing from disk. Default 5.
1400 @item lookahead_count
1401 Specify the number of lookahead fragments. Default 2.
1403 @item min_frag_duration
1404 Specify the minimum fragment duration (in microseconds). Default 5000000.
1406 @item remove_at_exit
1407 Specify whether to remove all fragments when finished. Default 0 (do not remove).
1413 The tee muxer can be used to write the same data to several files or any
1414 other kind of muxer. It can be used, for example, to both stream a video to
1415 the network and save it to disk at the same time.
1417 It is different from specifying several outputs to the @command{ffmpeg}
1418 command-line tool because the audio and video data will be encoded only once
1419 with the tee muxer; encoding can be a very expensive process. It is not
1420 useful when using the libavformat API directly because it is then possible
1421 to feed the same packets to several muxers directly.
1423 The slave outputs are specified in the file name given to the muxer,
1424 separated by '|'. If any of the slave name contains the '|' separator,
1425 leading or trailing spaces or any special character, it must be
1426 escaped (see @ref{quoting_and_escaping,,the "Quoting and escaping"
1427 section in the ffmpeg-utils(1) manual,ffmpeg-utils}).
1429 Muxer options can be specified for each slave by prepending them as a list of
1430 @var{key}=@var{value} pairs separated by ':', between square brackets. If
1431 the options values contain a special character or the ':' separator, they
1432 must be escaped; note that this is a second level escaping.
1434 The following special options are also recognized:
1437 Specify the format name. Useful if it cannot be guessed from the
1440 @item bsfs[/@var{spec}]
1441 Specify a list of bitstream filters to apply to the specified
1444 It is possible to specify to which streams a given bitstream filter
1445 applies, by appending a stream specifier to the option separated by
1446 @code{/}. @var{spec} must be a stream specifier (see @ref{Format
1447 stream specifiers}). If the stream specifier is not specified, the
1448 bitstream filters will be applied to all streams in the output.
1450 Several bitstream filters can be specified, separated by ",".
1453 Select the streams that should be mapped to the slave output,
1454 specified by a stream specifier. If not specified, this defaults to
1455 all the input streams. You may use multiple stream specifiers
1456 separated by commas (@code{,}) e.g.: @code{a:0,v}
1459 Specify behaviour on output failure. This can be set to either @code{abort} (which is
1460 default) or @code{ignore}. @code{abort} will cause whole process to fail in case of failure
1461 on this slave output. @code{ignore} will ignore failure on this output, so other outputs
1462 will continue without being affected.
1465 @subsection Examples
1469 Encode something and both archive it in a WebM file and stream it
1470 as MPEG-TS over UDP (the streams need to be explicitly mapped):
1472 ffmpeg -i ... -c:v libx264 -c:a mp2 -f tee -map 0:v -map 0:a
1473 "archive-20121107.mkv|[f=mpegts]udp://10.0.1.255:1234/"
1477 As above, but continue streaming even if output to local file fails
1478 (for example local drive fills up):
1480 ffmpeg -i ... -c:v libx264 -c:a mp2 -f tee -map 0:v -map 0:a
1481 "[onfail=ignore]archive-20121107.mkv|[f=mpegts]udp://10.0.1.255:1234/"
1485 Use @command{ffmpeg} to encode the input, and send the output
1486 to three different destinations. The @code{dump_extra} bitstream
1487 filter is used to add extradata information to all the output video
1488 keyframes packets, as requested by the MPEG-TS format. The select
1489 option is applied to @file{out.aac} in order to make it contain only
1492 ffmpeg -i ... -map 0 -flags +global_header -c:v libx264 -c:a aac -strict experimental
1493 -f tee "[bsfs/v=dump_extra]out.ts|[movflags=+faststart]out.mp4|[select=a]out.aac"
1497 As below, but select only stream @code{a:1} for the audio output. Note
1498 that a second level escaping must be performed, as ":" is a special
1499 character used to separate options.
1501 ffmpeg -i ... -map 0 -flags +global_header -c:v libx264 -c:a aac -strict experimental
1502 -f tee "[bsfs/v=dump_extra]out.ts|[movflags=+faststart]out.mp4|[select=\'a:1\']out.aac"
1506 Note: some codecs may need different options depending on the output format;
1507 the auto-detection of this can not work with the tee muxer. The main example
1508 is the @option{global_header} flag.
1510 @section webm_dash_manifest
1512 WebM DASH Manifest muxer.
1514 This muxer implements the WebM DASH Manifest specification to generate the DASH
1515 manifest XML. It also supports manifest generation for DASH live streams.
1517 For more information see:
1521 WebM DASH Specification: @url{https://sites.google.com/a/webmproject.org/wiki/adaptive-streaming/webm-dash-specification}
1523 ISO DASH Specification: @url{http://standards.iso.org/ittf/PubliclyAvailableStandards/c065274_ISO_IEC_23009-1_2014.zip}
1528 This muxer supports the following options:
1531 @item adaptation_sets
1532 This option has the following syntax: "id=x,streams=a,b,c id=y,streams=d,e" where x and y are the
1533 unique identifiers of the adaptation sets and a,b,c,d and e are the indices of the corresponding
1534 audio and video streams. Any number of adaptation sets can be added using this option.
1537 Set this to 1 to create a live stream DASH Manifest. Default: 0.
1539 @item chunk_start_index
1540 Start index of the first chunk. This will go in the @samp{startNumber} attribute
1541 of the @samp{SegmentTemplate} element in the manifest. Default: 0.
1543 @item chunk_duration_ms
1544 Duration of each chunk in milliseconds. This will go in the @samp{duration}
1545 attribute of the @samp{SegmentTemplate} element in the manifest. Default: 1000.
1547 @item utc_timing_url
1548 URL of the page that will return the UTC timestamp in ISO format. This will go
1549 in the @samp{value} attribute of the @samp{UTCTiming} element in the manifest.
1552 @item time_shift_buffer_depth
1553 Smallest time (in seconds) shifting buffer for which any Representation is
1554 guaranteed to be available. This will go in the @samp{timeShiftBufferDepth}
1555 attribute of the @samp{MPD} element. Default: 60.
1557 @item minimum_update_period
1558 Minimum update period (in seconds) of the manifest. This will go in the
1559 @samp{minimumUpdatePeriod} attribute of the @samp{MPD} element. Default: 0.
1565 ffmpeg -f webm_dash_manifest -i video1.webm \
1566 -f webm_dash_manifest -i video2.webm \
1567 -f webm_dash_manifest -i audio1.webm \
1568 -f webm_dash_manifest -i audio2.webm \
1569 -map 0 -map 1 -map 2 -map 3 \
1571 -f webm_dash_manifest \
1572 -adaptation_sets "id=0,streams=0,1 id=1,streams=2,3" \
1578 WebM Live Chunk Muxer.
1580 This muxer writes out WebM headers and chunks as separate files which can be
1581 consumed by clients that support WebM Live streams via DASH.
1585 This muxer supports the following options:
1588 @item chunk_start_index
1589 Index of the first chunk (defaults to 0).
1592 Filename of the header where the initialization data will be written.
1594 @item audio_chunk_duration
1595 Duration of each audio chunk in milliseconds (defaults to 5000).
1600 ffmpeg -f v4l2 -i /dev/video0 \
1604 -s 640x360 -keyint_min 30 -g 30 \
1606 -header webm_live_video_360.hdr \
1607 -chunk_start_index 1 \
1608 webm_live_video_360_%d.chk \
1613 -header webm_live_audio_128.hdr \
1614 -chunk_start_index 1 \
1615 -audio_chunk_duration 1000 \
1616 webm_live_audio_128_%d.chk