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 @code{hls_flags single_file} is set,
400 @var{filename} 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_flags round_durations
499 Round the duration info in the playlist file segment info to integer
500 values, instead of using floating point.
502 @item hls_flags discont_starts
503 Add the @code{#EXT-X-DISCONTINUITY} tag to the playlist, before the
504 first segment's information.
506 @item hls_flags omit_endlist
507 Do not append the @code{EXT-X-ENDLIST} tag at the end of the playlist.
509 @item hls_flags split_by_time
510 Allow segments to start on frames other than keyframes. This improves
511 behavior on some players when the time between keyframes is inconsistent,
512 but may make things worse on others, and can cause some oddities during
513 seeking. This flag should be used with the @code{hls_time} option.
515 @item hls_playlist_type event
516 Emit @code{#EXT-X-PLAYLIST-TYPE:EVENT} in the m3u8 header. Forces
517 @option{hls_list_size} to 0; the playlist can only be appended to.
519 @item hls_playlist_type vod
520 Emit @code{#EXT-X-PLAYLIST-TYPE:VOD} in the m3u8 header. Forces
521 @option{hls_list_size} to 0; the playlist must not change.
524 Use the given HTTP method to create the hls files.
526 ffmpeg -re -i in.ts -f hls -method PUT http://example.com/live/out.m3u8
528 This example will upload all the mpegts segment files to the HTTP
529 server using the HTTP PUT method, and update the m3u8 files every
530 @code{refresh} times using the same method.
531 Note that the HTTP server must support the given method for uploading
540 Microsoft's icon file format (ICO) has some strict limitations that should be noted:
544 Size cannot exceed 256 pixels in any dimension
547 Only BMP and PNG images can be stored
550 If a BMP image is used, it must be one of the following pixel formats:
552 BMP Bit Depth FFmpeg Pixel Format
562 If a BMP image is used, it must use the BITMAPINFOHEADER DIB header
565 If a PNG image is used, it must use the rgba pixel format
573 The image file muxer writes video frames to image files.
575 The output filenames are specified by a pattern, which can be used to
576 produce sequentially numbered series of files.
577 The pattern may contain the string "%d" or "%0@var{N}d", this string
578 specifies the position of the characters representing a numbering in
579 the filenames. If the form "%0@var{N}d" is used, the string
580 representing the number in each filename is 0-padded to @var{N}
581 digits. The literal character '%' can be specified in the pattern with
584 If the pattern contains "%d" or "%0@var{N}d", the first filename of
585 the file list specified will contain the number 1, all the following
586 numbers will be sequential.
588 The pattern may contain a suffix which is used to automatically
589 determine the format of the image files to write.
591 For example the pattern "img-%03d.bmp" will specify a sequence of
592 filenames of the form @file{img-001.bmp}, @file{img-002.bmp}, ...,
593 @file{img-010.bmp}, etc.
594 The pattern "img%%-%d.jpg" will specify a sequence of filenames of the
595 form @file{img%-1.jpg}, @file{img%-2.jpg}, ..., @file{img%-10.jpg},
600 The following example shows how to use @command{ffmpeg} for creating a
601 sequence of files @file{img-001.jpeg}, @file{img-002.jpeg}, ...,
602 taking one image every second from the input video:
604 ffmpeg -i in.avi -vsync 1 -r 1 -f image2 'img-%03d.jpeg'
607 Note that with @command{ffmpeg}, if the format is not specified with the
608 @code{-f} option and the output filename specifies an image file
609 format, the image2 muxer is automatically selected, so the previous
610 command can be written as:
612 ffmpeg -i in.avi -vsync 1 -r 1 'img-%03d.jpeg'
615 Note also that the pattern must not necessarily contain "%d" or
616 "%0@var{N}d", for example to create a single image file
617 @file{img.jpeg} from the input video you can employ the command:
619 ffmpeg -i in.avi -f image2 -frames:v 1 img.jpeg
622 The @option{strftime} option allows you to expand the filename with
623 date and time information. Check the documentation of
624 the @code{strftime()} function for the syntax.
626 For example to generate image files from the @code{strftime()}
627 "%Y-%m-%d_%H-%M-%S" pattern, the following @command{ffmpeg} command
630 ffmpeg -f v4l2 -r 1 -i /dev/video0 -f image2 -strftime 1 "%Y-%m-%d_%H-%M-%S.jpg"
637 Start the sequence from the specified number. Default value is 0.
640 If set to 1, the filename will always be interpreted as just a
641 filename, not a pattern, and the corresponding file will be continuously
642 overwritten with new images. Default value is 0.
645 If set to 1, expand the filename with date and time information from
646 @code{strftime()}. Default value is 0.
649 The image muxer supports the .Y.U.V image file format. This format is
650 special in that that each image frame consists of three files, for
651 each of the YUV420P components. To read or write this image file format,
652 specify the name of the '.Y' file. The muxer will automatically open the
653 '.U' and '.V' files as required.
657 Matroska container muxer.
659 This muxer implements the matroska and webm container specs.
663 The recognized metadata settings in this muxer are:
667 Set title name provided to a single track.
670 Specify the language of the track in the Matroska languages form.
672 The language can be either the 3 letters bibliographic ISO-639-2 (ISO
673 639-2/B) form (like "fre" for French), or a language code mixed with a
674 country code for specialities in languages (like "fre-ca" for Canadian
678 Set stereo 3D video layout of two views in a single video track.
680 The following values are recognized:
685 Both views are arranged side by side, Left-eye view is on the left
687 Both views are arranged in top-bottom orientation, Left-eye view is at bottom
689 Both views are arranged in top-bottom orientation, Left-eye view is on top
690 @item checkerboard_rl
691 Each view is arranged in a checkerboard interleaved pattern, Left-eye view being first
692 @item checkerboard_lr
693 Each view is arranged in a checkerboard interleaved pattern, Right-eye view being first
694 @item row_interleaved_rl
695 Each view is constituted by a row based interleaving, Right-eye view is first row
696 @item row_interleaved_lr
697 Each view is constituted by a row based interleaving, Left-eye view is first row
698 @item col_interleaved_rl
699 Both views are arranged in a column based interleaving manner, Right-eye view is first column
700 @item col_interleaved_lr
701 Both views are arranged in a column based interleaving manner, Left-eye view is first column
702 @item anaglyph_cyan_red
703 All frames are in anaglyph format viewable through red-cyan filters
705 Both views are arranged side by side, Right-eye view is on the left
706 @item anaglyph_green_magenta
707 All frames are in anaglyph format viewable through green-magenta filters
709 Both eyes laced in one Block, Left-eye view is first
711 Both eyes laced in one Block, Right-eye view is first
715 For example a 3D WebM clip can be created using the following command line:
717 ffmpeg -i sample_left_right_clip.mpg -an -c:v libvpx -metadata stereo_mode=left_right -y stereo_clip.webm
722 This muxer supports the following options:
725 @item reserve_index_space
726 By default, this muxer writes the index for seeking (called cues in Matroska
727 terms) at the end of the file, because it cannot know in advance how much space
728 to leave for the index at the beginning of the file. However for some use cases
729 -- e.g. streaming where seeking is possible but slow -- it is useful to put the
730 index at the beginning of the file.
732 If this option is set to a non-zero value, the muxer will reserve a given amount
733 of space in the file header and then try to write the cues there when the muxing
734 finishes. If the available space does not suffice, muxing will fail. A safe size
735 for most use cases should be about 50kB per hour of video.
737 Note that cues are only written if the output is seekable and this option will
738 have no effect if it is not.
746 This is a variant of the @ref{hash} muxer. Unlike that muxer, it
747 defaults to using the MD5 hash function.
751 To compute the MD5 hash of the input converted to raw
752 audio and video, and store it in the file @file{out.md5}:
754 ffmpeg -i INPUT -f md5 out.md5
757 You can print the MD5 to stdout with the command:
759 ffmpeg -i INPUT -f md5 -
762 See also the @ref{hash} and @ref{framemd5} muxers.
764 @section mov, mp4, ismv
766 MOV/MP4/ISMV (Smooth Streaming) muxer.
768 The mov/mp4/ismv muxer supports fragmentation. Normally, a MOV/MP4
769 file has all the metadata about all packets stored in one location
770 (written at the end of the file, it can be moved to the start for
771 better playback by adding @var{faststart} to the @var{movflags}, or
772 using the @command{qt-faststart} tool). A fragmented
773 file consists of a number of fragments, where packets and metadata
774 about these packets are stored together. Writing a fragmented
775 file has the advantage that the file is decodable even if the
776 writing is interrupted (while a normal MOV/MP4 is undecodable if
777 it is not properly finished), and it requires less memory when writing
778 very long files (since writing normal MOV/MP4 files stores info about
779 every single packet in memory until the file is closed). The downside
780 is that it is less compatible with other applications.
784 Fragmentation is enabled by setting one of the AVOptions that define
785 how to cut the file into fragments:
788 @item -moov_size @var{bytes}
789 Reserves space for the moov atom at the beginning of the file instead of placing the
790 moov atom at the end. If the space reserved is insufficient, muxing will fail.
791 @item -movflags frag_keyframe
792 Start a new fragment at each video keyframe.
793 @item -frag_duration @var{duration}
794 Create fragments that are @var{duration} microseconds long.
795 @item -frag_size @var{size}
796 Create fragments that contain up to @var{size} bytes of payload data.
797 @item -movflags frag_custom
798 Allow the caller to manually choose when to cut fragments, by
799 calling @code{av_write_frame(ctx, NULL)} to write a fragment with
800 the packets written so far. (This is only useful with other
801 applications integrating libavformat, not from @command{ffmpeg}.)
802 @item -min_frag_duration @var{duration}
803 Don't create fragments that are shorter than @var{duration} microseconds long.
806 If more than one condition is specified, fragments are cut when
807 one of the specified conditions is fulfilled. The exception to this is
808 @code{-min_frag_duration}, which has to be fulfilled for any of the other
811 Additionally, the way the output file is written can be adjusted
812 through a few other options:
815 @item -movflags empty_moov
816 Write an initial moov atom directly at the start of the file, without
817 describing any samples in it. Generally, an mdat/moov pair is written
818 at the start of the file, as a normal MOV/MP4 file, containing only
819 a short portion of the file. With this option set, there is no initial
820 mdat atom, and the moov atom only describes the tracks but has
823 This option is implicitly set when writing ismv (Smooth Streaming) files.
824 @item -movflags separate_moof
825 Write a separate moof (movie fragment) atom for each track. Normally,
826 packets for all tracks are written in a moof atom (which is slightly
827 more efficient), but with this option set, the muxer writes one moof/mdat
828 pair for each track, making it easier to separate tracks.
830 This option is implicitly set when writing ismv (Smooth Streaming) files.
831 @item -movflags faststart
832 Run a second pass moving the index (moov atom) to the beginning of the file.
833 This operation can take a while, and will not work in various situations such
834 as fragmented output, thus it is not enabled by default.
835 @item -movflags rtphint
836 Add RTP hinting tracks to the output file.
837 @item -movflags disable_chpl
838 Disable Nero chapter markers (chpl atom). Normally, both Nero chapters
839 and a QuickTime chapter track are written to the file. With this option
840 set, only the QuickTime chapter track will be written. Nero chapters can
841 cause failures when the file is reprocessed with certain tagging programs, like
842 mp3Tag 2.61a and iTunes 11.3, most likely other versions are affected as well.
843 @item -movflags omit_tfhd_offset
844 Do not write any absolute base_data_offset in tfhd atoms. This avoids
845 tying fragments to absolute byte positions in the file/streams.
846 @item -movflags default_base_moof
847 Similarly to the omit_tfhd_offset, this flag avoids writing the
848 absolute base_data_offset field in tfhd atoms, but does so by using
849 the new default-base-is-moof flag instead. This flag is new from
850 14496-12:2012. This may make the fragments easier to parse in certain
851 circumstances (avoiding basing track fragment location calculations
852 on the implicit end of the previous track fragment).
857 Smooth Streaming content can be pushed in real time to a publishing
858 point on IIS with this muxer. Example:
860 ffmpeg -re @var{<normal input/transcoding options>} -movflags isml+frag_keyframe -f ismv http://server/publishingpoint.isml/Streams(Encoder1)
863 @subsection Audible AAX
865 Audible AAX files are encrypted M4B files, and they can be decrypted by specifying a 4 byte activation secret.
867 ffmpeg -activation_bytes 1CEB00DA -i test.aax -vn -c:a copy output.mp4
872 The MP3 muxer writes a raw MP3 stream with the following optional features:
875 An ID3v2 metadata header at the beginning (enabled by default). Versions 2.3 and
876 2.4 are supported, the @code{id3v2_version} private option controls which one is
877 used (3 or 4). Setting @code{id3v2_version} to 0 disables the ID3v2 header
880 The muxer supports writing attached pictures (APIC frames) to the ID3v2 header.
881 The pictures are supplied to the muxer in form of a video stream with a single
882 packet. There can be any number of those streams, each will correspond to a
883 single APIC frame. The stream metadata tags @var{title} and @var{comment} map
884 to APIC @var{description} and @var{picture type} respectively. See
885 @url{http://id3.org/id3v2.4.0-frames} for allowed picture types.
887 Note that the APIC frames must be written at the beginning, so the muxer will
888 buffer the audio frames until it gets all the pictures. It is therefore advised
889 to provide the pictures as soon as possible to avoid excessive buffering.
892 A Xing/LAME frame right after the ID3v2 header (if present). It is enabled by
893 default, but will be written only if the output is seekable. The
894 @code{write_xing} private option can be used to disable it. The frame contains
895 various information that may be useful to the decoder, like the audio duration
899 A legacy ID3v1 tag at the end of the file (disabled by default). It may be
900 enabled with the @code{write_id3v1} private option, but as its capabilities are
901 very limited, its usage is not recommended.
906 Write an mp3 with an ID3v2.3 header and an ID3v1 footer:
908 ffmpeg -i INPUT -id3v2_version 3 -write_id3v1 1 out.mp3
911 To attach a picture to an mp3 file select both the audio and the picture stream
914 ffmpeg -i input.mp3 -i cover.png -c copy -map 0 -map 1
915 -metadata:s:v title="Album cover" -metadata:s:v comment="Cover (Front)" out.mp3
918 Write a "clean" MP3 without any extra features:
920 ffmpeg -i input.wav -write_xing 0 -id3v2_version 0 out.mp3
925 MPEG transport stream muxer.
927 This muxer implements ISO 13818-1 and part of ETSI EN 300 468.
929 The recognized metadata settings in mpegts muxer are @code{service_provider}
930 and @code{service_name}. If they are not set the default for
931 @code{service_provider} is "FFmpeg" and the default for
932 @code{service_name} is "Service01".
936 The muxer options are:
939 @item mpegts_original_network_id @var{number}
940 Set the original_network_id (default 0x0001). This is unique identifier
941 of a network in DVB. Its main use is in the unique identification of a
942 service through the path Original_Network_ID, Transport_Stream_ID.
943 @item mpegts_transport_stream_id @var{number}
944 Set the transport_stream_id (default 0x0001). This identifies a
946 @item mpegts_service_id @var{number}
947 Set the service_id (default 0x0001) also known as program in DVB.
948 @item mpegts_service_type @var{number}
949 Set the program service_type (default @var{digital_tv}), see below
950 a list of pre defined values.
951 @item mpegts_pmt_start_pid @var{number}
952 Set the first PID for PMT (default 0x1000, max 0x1f00).
953 @item mpegts_start_pid @var{number}
954 Set the first PID for data packets (default 0x0100, max 0x0f00).
955 @item mpegts_m2ts_mode @var{number}
956 Enable m2ts mode if set to 1. Default value is -1 which disables m2ts mode.
957 @item muxrate @var{number}
958 Set a constant muxrate (default VBR).
959 @item pcr_period @var{numer}
960 Override the default PCR retransmission time (default 20ms), ignored
961 if variable muxrate is selected.
962 @item pat_period @var{number}
963 Maximal time in seconds between PAT/PMT tables.
964 @item sdt_period @var{number}
965 Maximal time in seconds between SDT tables.
966 @item pes_payload_size @var{number}
967 Set minimum PES packet payload in bytes.
968 @item mpegts_flags @var{flags}
969 Set flags (see below).
970 @item mpegts_copyts @var{number}
971 Preserve original timestamps, if value is set to 1. Default value is -1, which
972 results in shifting timestamps so that they start from 0.
973 @item tables_version @var{number}
974 Set PAT, PMT and SDT version (default 0, valid values are from 0 to 31, inclusively).
975 This option allows updating stream structure so that standard consumer may
976 detect the change. To do so, reopen output AVFormatContext (in case of API
977 usage) or restart ffmpeg instance, cyclically changing tables_version value:
979 ffmpeg -i source1.ts -codec copy -f mpegts -tables_version 0 udp://1.1.1.1:1111
980 ffmpeg -i source2.ts -codec copy -f mpegts -tables_version 1 udp://1.1.1.1:1111
982 ffmpeg -i source3.ts -codec copy -f mpegts -tables_version 31 udp://1.1.1.1:1111
983 ffmpeg -i source1.ts -codec copy -f mpegts -tables_version 0 udp://1.1.1.1:1111
984 ffmpeg -i source2.ts -codec copy -f mpegts -tables_version 1 udp://1.1.1.1:1111
989 Option @option{mpegts_service_type} accepts the following values:
993 Any hexdecimal value between 0x01 to 0xff as defined in ETSI 300 468.
997 Digital Radio service.
1000 @item advanced_codec_digital_radio
1001 Advanced Codec Digital Radio service.
1002 @item mpeg2_digital_hdtv
1003 MPEG2 Digital HDTV service.
1004 @item advanced_codec_digital_sdtv
1005 Advanced Codec Digital SDTV service.
1006 @item advanced_codec_digital_hdtv
1007 Advanced Codec Digital HDTV service.
1010 Option @option{mpegts_flags} may take a set of such flags:
1013 @item resend_headers
1014 Reemit PAT/PMT before writing the next packet.
1016 Use LATM packetization for AAC.
1017 @item pat_pmt_at_frames
1018 Reemit PAT and PMT at each video frame.
1020 Conform to System B (DVB) instead of System A (ATSC).
1026 ffmpeg -i file.mpg -c copy \
1027 -mpegts_original_network_id 0x1122 \
1028 -mpegts_transport_stream_id 0x3344 \
1029 -mpegts_service_id 0x5566 \
1030 -mpegts_pmt_start_pid 0x1500 \
1031 -mpegts_start_pid 0x150 \
1032 -metadata service_provider="Some provider" \
1033 -metadata service_name="Some Channel" \
1037 @section mxf, mxf_d10
1043 The muxer options are:
1046 @item store_user_comments @var{bool}
1047 Set if user comments should be stored if available or never.
1048 IRT D-10 does not allow user comments. The default is thus to write them for
1049 mxf but not for mxf_d10
1056 This muxer does not generate any output file, it is mainly useful for
1057 testing or benchmarking purposes.
1059 For example to benchmark decoding with @command{ffmpeg} you can use the
1062 ffmpeg -benchmark -i INPUT -f null out.null
1065 Note that the above command does not read or write the @file{out.null}
1066 file, but specifying the output file is required by the @command{ffmpeg}
1069 Alternatively you can write the command as:
1071 ffmpeg -benchmark -i INPUT -f null -
1077 @item -syncpoints @var{flags}
1078 Change the syncpoint usage in nut:
1080 @item @var{default} use the normal low-overhead seeking aids.
1081 @item @var{none} do not use the syncpoints at all, reducing the overhead but making the stream non-seekable;
1082 Use of this option is not recommended, as the resulting files are very damage
1083 sensitive and seeking is not possible. Also in general the overhead from
1084 syncpoints is negligible. Note, -@code{write_index} 0 can be used to disable
1085 all growing data tables, allowing to mux endless streams with limited memory
1086 and without these disadvantages.
1087 @item @var{timestamped} extend the syncpoint with a wallclock field.
1089 The @var{none} and @var{timestamped} flags are experimental.
1090 @item -write_index @var{bool}
1091 Write index at the end, the default is to write an index.
1095 ffmpeg -i INPUT -f_strict experimental -syncpoints none - | processor
1100 Ogg container muxer.
1103 @item -page_duration @var{duration}
1104 Preferred page duration, in microseconds. The muxer will attempt to create
1105 pages that are approximately @var{duration} microseconds long. This allows the
1106 user to compromise between seek granularity and container overhead. The default
1107 is 1 second. A value of 0 will fill all segments, making pages as large as
1108 possible. A value of 1 will effectively use 1 packet-per-page in most
1109 situations, giving a small seek granularity at the cost of additional container
1111 @item -serial_offset @var{value}
1112 Serial value from which to set the streams serial number.
1113 Setting it to different and sufficiently large values ensures that the produced
1114 ogg files can be safely chained.
1119 @section segment, stream_segment, ssegment
1121 Basic stream segmenter.
1123 This muxer outputs streams to a number of separate files of nearly
1124 fixed duration. Output filename pattern can be set in a fashion
1125 similar to @ref{image2}, or by using a @code{strftime} template if
1126 the @option{strftime} option is enabled.
1128 @code{stream_segment} is a variant of the muxer used to write to
1129 streaming output formats, i.e. which do not require global headers,
1130 and is recommended for outputting e.g. to MPEG transport stream segments.
1131 @code{ssegment} is a shorter alias for @code{stream_segment}.
1133 Every segment starts with a keyframe of the selected reference stream,
1134 which is set through the @option{reference_stream} option.
1136 Note that if you want accurate splitting for a video file, you need to
1137 make the input key frames correspond to the exact splitting times
1138 expected by the segmenter, or the segment muxer will start the new
1139 segment with the key frame found next after the specified start
1142 The segment muxer works best with a single constant frame rate video.
1144 Optionally it can generate a list of the created segments, by setting
1145 the option @var{segment_list}. The list type is specified by the
1146 @var{segment_list_type} option. The entry filenames in the segment
1147 list are set by default to the basename of the corresponding segment
1150 See also the @ref{hls} muxer, which provides a more specific
1151 implementation for HLS segmentation.
1155 The segment muxer supports the following options:
1158 @item increment_tc @var{1|0}
1159 if set to @code{1}, increment timecode between each segment
1160 If this is selected, the input need to have
1161 a timecode in the first video stream. Default value is
1164 @item reference_stream @var{specifier}
1165 Set the reference stream, as specified by the string @var{specifier}.
1166 If @var{specifier} is set to @code{auto}, the reference is chosen
1167 automatically. Otherwise it must be a stream specifier (see the ``Stream
1168 specifiers'' chapter in the ffmpeg manual) which specifies the
1169 reference stream. The default value is @code{auto}.
1171 @item segment_format @var{format}
1172 Override the inner container format, by default it is guessed by the filename
1175 @item segment_format_options @var{options_list}
1176 Set output format options using a :-separated list of key=value
1177 parameters. Values containing the @code{:} special character must be
1180 @item segment_list @var{name}
1181 Generate also a listfile named @var{name}. If not specified no
1182 listfile is generated.
1184 @item segment_list_flags @var{flags}
1185 Set flags affecting the segment list generation.
1187 It currently supports the following flags:
1190 Allow caching (only affects M3U8 list files).
1193 Allow live-friendly file generation.
1196 @item segment_list_size @var{size}
1197 Update the list file so that it contains at most @var{size}
1198 segments. If 0 the list file will contain all the segments. Default
1201 @item segment_list_entry_prefix @var{prefix}
1202 Prepend @var{prefix} to each entry. Useful to generate absolute paths.
1203 By default no prefix is applied.
1205 @item segment_list_type @var{type}
1206 Select the listing format.
1208 The following values are recognized:
1211 Generate a flat list for the created segments, one segment per line.
1214 Generate a list for the created segments, one segment per line,
1215 each line matching the format (comma-separated values):
1217 @var{segment_filename},@var{segment_start_time},@var{segment_end_time}
1220 @var{segment_filename} is the name of the output file generated by the
1221 muxer according to the provided pattern. CSV escaping (according to
1222 RFC4180) is applied if required.
1224 @var{segment_start_time} and @var{segment_end_time} specify
1225 the segment start and end time expressed in seconds.
1227 A list file with the suffix @code{".csv"} or @code{".ext"} will
1228 auto-select this format.
1230 @samp{ext} is deprecated in favor or @samp{csv}.
1233 Generate an ffconcat file for the created segments. The resulting file
1234 can be read using the FFmpeg @ref{concat} demuxer.
1236 A list file with the suffix @code{".ffcat"} or @code{".ffconcat"} will
1237 auto-select this format.
1240 Generate an extended M3U8 file, version 3, compliant with
1241 @url{http://tools.ietf.org/id/draft-pantos-http-live-streaming}.
1243 A list file with the suffix @code{".m3u8"} will auto-select this format.
1246 If not specified the type is guessed from the list file name suffix.
1248 @item segment_time @var{time}
1249 Set segment duration to @var{time}, the value must be a duration
1250 specification. Default value is "2". See also the
1251 @option{segment_times} option.
1253 Note that splitting may not be accurate, unless you force the
1254 reference stream key-frames at the given time. See the introductory
1255 notice and the examples below.
1257 @item segment_atclocktime @var{1|0}
1258 If set to "1" split at regular clock time intervals starting from 00:00
1259 o'clock. The @var{time} value specified in @option{segment_time} is
1260 used for setting the length of the splitting interval.
1262 For example with @option{segment_time} set to "900" this makes it possible
1263 to create files at 12:00 o'clock, 12:15, 12:30, etc.
1265 Default value is "0".
1267 @item segment_clocktime_offset @var{duration}
1268 Delay the segment splitting times with the specified duration when using
1269 @option{segment_atclocktime}.
1271 For example with @option{segment_time} set to "900" and
1272 @option{segment_clocktime_offset} set to "300" this makes it possible to
1273 create files at 12:05, 12:20, 12:35, etc.
1275 Default value is "0".
1277 @item segment_clocktime_wrap_duration @var{duration}
1278 Force the segmenter to only start a new segment if a packet reaches the muxer
1279 within the specified duration after the segmenting clock time. This way you
1280 can make the segmenter more resilient to backward local time jumps, such as
1281 leap seconds or transition to standard time from daylight savings time.
1283 Assuming that the delay between the packets of your source is less than 0.5
1284 second you can detect a leap second by specifying 0.5 as the duration.
1286 Default is the maximum possible duration which means starting a new segment
1287 regardless of the elapsed time since the last clock time.
1289 @item segment_time_delta @var{delta}
1290 Specify the accuracy time when selecting the start time for a
1291 segment, expressed as a duration specification. Default value is "0".
1293 When delta is specified a key-frame will start a new segment if its
1294 PTS satisfies the relation:
1296 PTS >= start_time - time_delta
1299 This option is useful when splitting video content, which is always
1300 split at GOP boundaries, in case a key frame is found just before the
1301 specified split time.
1303 In particular may be used in combination with the @file{ffmpeg} option
1304 @var{force_key_frames}. The key frame times specified by
1305 @var{force_key_frames} may not be set accurately because of rounding
1306 issues, with the consequence that a key frame time may result set just
1307 before the specified time. For constant frame rate videos a value of
1308 1/(2*@var{frame_rate}) should address the worst case mismatch between
1309 the specified time and the time set by @var{force_key_frames}.
1311 @item segment_times @var{times}
1312 Specify a list of split points. @var{times} contains a list of comma
1313 separated duration specifications, in increasing order. See also
1314 the @option{segment_time} option.
1316 @item segment_frames @var{frames}
1317 Specify a list of split video frame numbers. @var{frames} contains a
1318 list of comma separated integer numbers, in increasing order.
1320 This option specifies to start a new segment whenever a reference
1321 stream key frame is found and the sequential number (starting from 0)
1322 of the frame is greater or equal to the next value in the list.
1324 @item segment_wrap @var{limit}
1325 Wrap around segment index once it reaches @var{limit}.
1327 @item segment_start_number @var{number}
1328 Set the sequence number of the first segment. Defaults to @code{0}.
1330 @item strftime @var{1|0}
1331 Use the @code{strftime} function to define the name of the new
1332 segments to write. If this is selected, the output segment name must
1333 contain a @code{strftime} function template. Default value is
1336 @item break_non_keyframes @var{1|0}
1337 If enabled, allow segments to start on frames other than keyframes. This
1338 improves behavior on some players when the time between keyframes is
1339 inconsistent, but may make things worse on others, and can cause some oddities
1340 during seeking. Defaults to @code{0}.
1342 @item reset_timestamps @var{1|0}
1343 Reset timestamps at the begin of each segment, so that each segment
1344 will start with near-zero timestamps. It is meant to ease the playback
1345 of the generated segments. May not work with some combinations of
1346 muxers/codecs. It is set to @code{0} by default.
1348 @item initial_offset @var{offset}
1349 Specify timestamp offset to apply to the output packet timestamps. The
1350 argument must be a time duration specification, and defaults to 0.
1352 @item write_empty_segments @var{1|0}
1353 If enabled, write an empty segment if there are no packets during the period a
1354 segment would usually span. Otherwise, the segment will be filled with the next
1355 packet written. Defaults to @code{0}.
1358 @subsection Examples
1362 Remux the content of file @file{in.mkv} to a list of segments
1363 @file{out-000.nut}, @file{out-001.nut}, etc., and write the list of
1364 generated segments to @file{out.list}:
1366 ffmpeg -i in.mkv -codec copy -map 0 -f segment -segment_list out.list out%03d.nut
1370 Segment input and set output format options for the output segments:
1372 ffmpeg -i in.mkv -f segment -segment_time 10 -segment_format_options movflags=+faststart out%03d.mp4
1376 Segment the input file according to the split points specified by the
1377 @var{segment_times} option:
1379 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
1383 Use the @command{ffmpeg} @option{force_key_frames}
1384 option to force key frames in the input at the specified location, together
1385 with the segment option @option{segment_time_delta} to account for
1386 possible roundings operated when setting key frame times.
1388 ffmpeg -i in.mkv -force_key_frames 1,2,3,5,8,13,21 -codec:v mpeg4 -codec:a pcm_s16le -map 0 \
1389 -f segment -segment_list out.csv -segment_times 1,2,3,5,8,13,21 -segment_time_delta 0.05 out%03d.nut
1391 In order to force key frames on the input file, transcoding is
1395 Segment the input file by splitting the input file according to the
1396 frame numbers sequence specified with the @option{segment_frames} option:
1398 ffmpeg -i in.mkv -codec copy -map 0 -f segment -segment_list out.csv -segment_frames 100,200,300,500,800 out%03d.nut
1402 Convert the @file{in.mkv} to TS segments using the @code{libx264}
1403 and @code{libfaac} encoders:
1405 ffmpeg -i in.mkv -map 0 -codec:v libx264 -codec:a libfaac -f ssegment -segment_list out.list out%03d.ts
1409 Segment the input file, and create an M3U8 live playlist (can be used
1410 as live HLS source):
1412 ffmpeg -re -i in.mkv -codec copy -map 0 -f segment -segment_list playlist.m3u8 \
1413 -segment_list_flags +live -segment_time 10 out%03d.mkv
1417 @section smoothstreaming
1419 Smooth Streaming muxer generates a set of files (Manifest, chunks) suitable for serving with conventional web server.
1423 Specify the number of fragments kept in the manifest. Default 0 (keep all).
1425 @item extra_window_size
1426 Specify the number of fragments kept outside of the manifest before removing from disk. Default 5.
1428 @item lookahead_count
1429 Specify the number of lookahead fragments. Default 2.
1431 @item min_frag_duration
1432 Specify the minimum fragment duration (in microseconds). Default 5000000.
1434 @item remove_at_exit
1435 Specify whether to remove all fragments when finished. Default 0 (do not remove).
1441 The tee muxer can be used to write the same data to several files or any
1442 other kind of muxer. It can be used, for example, to both stream a video to
1443 the network and save it to disk at the same time.
1445 It is different from specifying several outputs to the @command{ffmpeg}
1446 command-line tool because the audio and video data will be encoded only once
1447 with the tee muxer; encoding can be a very expensive process. It is not
1448 useful when using the libavformat API directly because it is then possible
1449 to feed the same packets to several muxers directly.
1451 The slave outputs are specified in the file name given to the muxer,
1452 separated by '|'. If any of the slave name contains the '|' separator,
1453 leading or trailing spaces or any special character, it must be
1454 escaped (see @ref{quoting_and_escaping,,the "Quoting and escaping"
1455 section in the ffmpeg-utils(1) manual,ffmpeg-utils}).
1457 Muxer options can be specified for each slave by prepending them as a list of
1458 @var{key}=@var{value} pairs separated by ':', between square brackets. If
1459 the options values contain a special character or the ':' separator, they
1460 must be escaped; note that this is a second level escaping.
1462 The following special options are also recognized:
1465 Specify the format name. Useful if it cannot be guessed from the
1468 @item bsfs[/@var{spec}]
1469 Specify a list of bitstream filters to apply to the specified
1472 It is possible to specify to which streams a given bitstream filter
1473 applies, by appending a stream specifier to the option separated by
1474 @code{/}. @var{spec} must be a stream specifier (see @ref{Format
1475 stream specifiers}). If the stream specifier is not specified, the
1476 bitstream filters will be applied to all streams in the output.
1478 Several bitstream filters can be specified, separated by ",".
1481 Select the streams that should be mapped to the slave output,
1482 specified by a stream specifier. If not specified, this defaults to
1483 all the input streams. You may use multiple stream specifiers
1484 separated by commas (@code{,}) e.g.: @code{a:0,v}
1487 Specify behaviour on output failure. This can be set to either @code{abort} (which is
1488 default) or @code{ignore}. @code{abort} will cause whole process to fail in case of failure
1489 on this slave output. @code{ignore} will ignore failure on this output, so other outputs
1490 will continue without being affected.
1493 @subsection Examples
1497 Encode something and both archive it in a WebM file and stream it
1498 as MPEG-TS over UDP (the streams need to be explicitly mapped):
1500 ffmpeg -i ... -c:v libx264 -c:a mp2 -f tee -map 0:v -map 0:a
1501 "archive-20121107.mkv|[f=mpegts]udp://10.0.1.255:1234/"
1505 As above, but continue streaming even if output to local file fails
1506 (for example local drive fills up):
1508 ffmpeg -i ... -c:v libx264 -c:a mp2 -f tee -map 0:v -map 0:a
1509 "[onfail=ignore]archive-20121107.mkv|[f=mpegts]udp://10.0.1.255:1234/"
1513 Use @command{ffmpeg} to encode the input, and send the output
1514 to three different destinations. The @code{dump_extra} bitstream
1515 filter is used to add extradata information to all the output video
1516 keyframes packets, as requested by the MPEG-TS format. The select
1517 option is applied to @file{out.aac} in order to make it contain only
1520 ffmpeg -i ... -map 0 -flags +global_header -c:v libx264 -c:a aac -strict experimental
1521 -f tee "[bsfs/v=dump_extra]out.ts|[movflags=+faststart]out.mp4|[select=a]out.aac"
1525 As below, but select only stream @code{a:1} for the audio output. Note
1526 that a second level escaping must be performed, as ":" is a special
1527 character used to separate options.
1529 ffmpeg -i ... -map 0 -flags +global_header -c:v libx264 -c:a aac -strict experimental
1530 -f tee "[bsfs/v=dump_extra]out.ts|[movflags=+faststart]out.mp4|[select=\'a:1\']out.aac"
1534 Note: some codecs may need different options depending on the output format;
1535 the auto-detection of this can not work with the tee muxer. The main example
1536 is the @option{global_header} flag.
1538 @section webm_dash_manifest
1540 WebM DASH Manifest muxer.
1542 This muxer implements the WebM DASH Manifest specification to generate the DASH
1543 manifest XML. It also supports manifest generation for DASH live streams.
1545 For more information see:
1549 WebM DASH Specification: @url{https://sites.google.com/a/webmproject.org/wiki/adaptive-streaming/webm-dash-specification}
1551 ISO DASH Specification: @url{http://standards.iso.org/ittf/PubliclyAvailableStandards/c065274_ISO_IEC_23009-1_2014.zip}
1556 This muxer supports the following options:
1559 @item adaptation_sets
1560 This option has the following syntax: "id=x,streams=a,b,c id=y,streams=d,e" where x and y are the
1561 unique identifiers of the adaptation sets and a,b,c,d and e are the indices of the corresponding
1562 audio and video streams. Any number of adaptation sets can be added using this option.
1565 Set this to 1 to create a live stream DASH Manifest. Default: 0.
1567 @item chunk_start_index
1568 Start index of the first chunk. This will go in the @samp{startNumber} attribute
1569 of the @samp{SegmentTemplate} element in the manifest. Default: 0.
1571 @item chunk_duration_ms
1572 Duration of each chunk in milliseconds. This will go in the @samp{duration}
1573 attribute of the @samp{SegmentTemplate} element in the manifest. Default: 1000.
1575 @item utc_timing_url
1576 URL of the page that will return the UTC timestamp in ISO format. This will go
1577 in the @samp{value} attribute of the @samp{UTCTiming} element in the manifest.
1580 @item time_shift_buffer_depth
1581 Smallest time (in seconds) shifting buffer for which any Representation is
1582 guaranteed to be available. This will go in the @samp{timeShiftBufferDepth}
1583 attribute of the @samp{MPD} element. Default: 60.
1585 @item minimum_update_period
1586 Minimum update period (in seconds) of the manifest. This will go in the
1587 @samp{minimumUpdatePeriod} attribute of the @samp{MPD} element. Default: 0.
1593 ffmpeg -f webm_dash_manifest -i video1.webm \
1594 -f webm_dash_manifest -i video2.webm \
1595 -f webm_dash_manifest -i audio1.webm \
1596 -f webm_dash_manifest -i audio2.webm \
1597 -map 0 -map 1 -map 2 -map 3 \
1599 -f webm_dash_manifest \
1600 -adaptation_sets "id=0,streams=0,1 id=1,streams=2,3" \
1606 WebM Live Chunk Muxer.
1608 This muxer writes out WebM headers and chunks as separate files which can be
1609 consumed by clients that support WebM Live streams via DASH.
1613 This muxer supports the following options:
1616 @item chunk_start_index
1617 Index of the first chunk (defaults to 0).
1620 Filename of the header where the initialization data will be written.
1622 @item audio_chunk_duration
1623 Duration of each audio chunk in milliseconds (defaults to 5000).
1628 ffmpeg -f v4l2 -i /dev/video0 \
1632 -s 640x360 -keyint_min 30 -g 30 \
1634 -header webm_live_video_360.hdr \
1635 -chunk_start_index 1 \
1636 webm_live_video_360_%d.chk \
1641 -header webm_live_audio_128.hdr \
1642 -chunk_start_index 1 \
1643 -audio_chunk_duration 1000 \
1644 webm_live_audio_128_%d.chk