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{-muxers} of the ff* tools will display the list of
17 enabled muxers. Use @code{-formats} to view a combined list of
18 enabled demuxers and muxers.
20 A description of some of the currently available muxers follows.
25 Audio Interchange File Format muxer.
29 It accepts the following options:
33 Enable ID3v2 tags writing when set to 1. Default is 0 (disabled).
36 Select ID3v2 version to write. Currently only version 3 and 4 (aka.
37 ID3v2.3 and ID3v2.4) are supported. The default is version 4.
44 Advanced Systems Format muxer.
46 Note that Windows Media Audio (wma) and Windows Media Video (wmv) use this
51 It accepts the following options:
55 Set the muxer packet size. By tuning this setting you may reduce data
56 fragmentation or muxer overhead depending on your source. Default value is
57 3200, minimum is 100, maximum is 64k.
64 Audio Video Interleaved muxer.
68 It accepts the following options:
71 @item reserve_index_space
72 Reserve the specified amount of bytes for the OpenDML master index of each
73 stream within the file header. By default additional master indexes are
74 embedded within the data packets if there is no space left in the first master
75 index and are linked together as a chain of indexes. This index structure can
76 cause problems for some use cases, e.g. third-party software strictly relying
77 on the OpenDML index specification or when file seeking is slow. Reserving
78 enough index space in the file header avoids these problems.
80 The required index space depends on the output file size and should be about 16
81 bytes per gigabyte. When this option is omitted or set to zero the necessary
82 index space is guessed.
84 @item write_channel_mask
85 Write the channel layout mask into the audio stream header.
87 This option is enabled by default. Disabling the channel mask can be useful in
88 specific scenarios, e.g. when merging multiple audio streams into one for
89 compatibility with software that only supports a single audio stream in AVI
90 (see @ref{amerge,,the "amerge" section in the ffmpeg-filters manual,ffmpeg-filters}).
97 Chromaprint fingerprinter
99 This muxer feeds audio data to the Chromaprint library, which generates
100 a fingerprint for the provided audio data. It takes a single signed
101 native-endian 16-bit raw audio stream.
106 @item silence_threshold
107 Threshold for detecting silence, ranges from 0 to 32767. -1 for default
108 (required for use with the AcoustID service).
111 Algorithm index to fingerprint with.
114 Format to output the fingerprint as. Accepts the following options:
117 Binary raw fingerprint
120 Binary compressed fingerprint
123 Base64 compressed fingerprint
132 CRC (Cyclic Redundancy Check) testing format.
134 This muxer computes and prints the Adler-32 CRC of all the input audio
135 and video frames. By default audio frames are converted to signed
136 16-bit raw audio and video frames to raw video before computing the
139 The output of the muxer consists of a single line of the form:
140 CRC=0x@var{CRC}, where @var{CRC} is a hexadecimal number 0-padded to
141 8 digits containing the CRC for all the decoded input frames.
143 See also the @ref{framecrc} muxer.
147 For example to compute the CRC of the input, and store it in the file
150 ffmpeg -i INPUT -f crc out.crc
153 You can print the CRC to stdout with the command:
155 ffmpeg -i INPUT -f crc -
158 You can select the output format of each frame with @command{ffmpeg} by
159 specifying the audio and video codec and format. For example to
160 compute the CRC of the input audio converted to PCM unsigned 8-bit
161 and the input video converted to MPEG-2 video, use the command:
163 ffmpeg -i INPUT -c:a pcm_u8 -c:v mpeg2video -f crc -
168 Adobe Flash Video Format muxer.
170 This muxer accepts the following options:
174 @item flvflags @var{flags}
179 @item aac_seq_header_detect
180 Place AAC sequence header based on audio stream data.
182 @item no_sequence_end
183 Disable sequence end tag.
186 Disable metadata tag.
188 @item no_duration_filesize
189 Disable duration and filesize in metadata when they are equal to zero
190 at the end of stream. (Be used to non-seekable living stream).
192 @item add_keyframe_index
193 Used to facilitate seeking; particularly for HTTP pseudo streaming.
200 Dynamic Adaptive Streaming over HTTP (DASH) muxer that creates segments
201 and manifest files according to the MPEG-DASH standard ISO/IEC 23009-1:2014.
203 For more information see:
207 ISO DASH Specification: @url{http://standards.iso.org/ittf/PubliclyAvailableStandards/c065274_ISO_IEC_23009-1_2014.zip}
209 WebM DASH Specification: @url{https://sites.google.com/a/webmproject.org/wiki/adaptive-streaming/webm-dash-specification}
212 It creates a MPD manifest file and segment files for each stream.
214 The segment filename might contain pre-defined identifiers used with SegmentTemplate
215 as defined in section 5.3.9.4.4 of the standard. Available identifiers are "$RepresentationID$",
216 "$Number$", "$Bandwidth$" and "$Time$".
219 ffmpeg -re -i <input> -map 0 -map 0 -c:a libfdk_aac -c:v libx264
220 -b:v:0 800k -b:v:1 300k -s:v:1 320x170 -profile:v:1 baseline
221 -profile:v:0 main -bf 1 -keyint_min 120 -g 120 -sc_threshold 0
222 -b_strategy 0 -ar:a:1 22050 -use_timeline 1 -use_template 1
223 -window_size 5 -adaptation_sets "id=0,streams=v id=1,streams=a"
224 -f dash /path/to/out.mpd
228 @item -min_seg_duration @var{microseconds}
229 Set the segment length in microseconds.
230 @item -window_size @var{size}
231 Set the maximum number of segments kept in the manifest.
232 @item -extra_window_size @var{size}
233 Set the maximum number of segments kept outside of the manifest before removing from disk.
234 @item -remove_at_exit @var{remove}
235 Enable (1) or disable (0) removal of all segments when finished.
236 @item -use_template @var{template}
237 Enable (1) or disable (0) use of SegmentTemplate instead of SegmentList.
238 @item -use_timeline @var{timeline}
239 Enable (1) or disable (0) use of SegmentTimeline in SegmentTemplate.
240 @item -single_file @var{single_file}
241 Enable (1) or disable (0) storing all segments in one file, accessed using byte ranges.
242 @item -single_file_name @var{file_name}
243 DASH-templated name to be used for baseURL. Implies @var{single_file} set to "1".
244 @item -init_seg_name @var{init_name}
245 DASH-templated name to used for the initialization segment. Default is "init-stream$RepresentationID$.m4s"
246 @item -media_seg_name @var{segment_name}
247 DASH-templated name to used for the media segments. Default is "chunk-stream$RepresentationID$-$Number%05d$.m4s"
248 @item -utc_timing_url @var{utc_url}
249 URL of the page that will return the UTC timestamp in ISO format. Example: "https://time.akamai.com/?iso"
250 @item -http_user_agent @var{user_agent}
251 Override User-Agent field in HTTP header. Applicable only for HTTP output.
252 @item -adaptation_sets @var{adaptation_sets}
253 Assign streams to AdaptationSets. Syntax is "id=x,streams=a,b,c id=y,streams=d,e" with x and y being the IDs
254 of the adaptation sets and a,b,c,d and e are the indices of the mapped streams.
256 To map all video (or audio) streams to an AdaptationSet, "v" (or "a") can be used as stream identifier instead of IDs.
258 When no assignment is defined, this defaults to an AdaptationSet for each stream.
264 Per-packet CRC (Cyclic Redundancy Check) testing format.
266 This muxer computes and prints the Adler-32 CRC for each audio
267 and video packet. By default audio frames are converted to signed
268 16-bit raw audio and video frames to raw video before computing the
271 The output of the muxer consists of a line for each audio and video
274 @var{stream_index}, @var{packet_dts}, @var{packet_pts}, @var{packet_duration}, @var{packet_size}, 0x@var{CRC}
277 @var{CRC} is a hexadecimal number 0-padded to 8 digits containing the
282 For example to compute the CRC of the audio and video frames in
283 @file{INPUT}, converted to raw audio and video packets, and store it
284 in the file @file{out.crc}:
286 ffmpeg -i INPUT -f framecrc out.crc
289 To print the information to stdout, use the command:
291 ffmpeg -i INPUT -f framecrc -
294 With @command{ffmpeg}, you can select the output format to which the
295 audio and video frames are encoded before computing the CRC for each
296 packet by specifying the audio and video codec. For example, to
297 compute the CRC of each decoded input audio frame converted to PCM
298 unsigned 8-bit and of each decoded input video frame converted to
299 MPEG-2 video, use the command:
301 ffmpeg -i INPUT -c:a pcm_u8 -c:v mpeg2video -f framecrc -
304 See also the @ref{crc} muxer.
309 Per-packet hash testing format.
311 This muxer computes and prints a cryptographic hash for each audio
312 and video packet. This can be used for packet-by-packet equality
313 checks without having to individually do a binary comparison on each.
315 By default audio frames are converted to signed 16-bit raw audio and
316 video frames to raw video before computing the hash, but the output
317 of explicit conversions to other codecs can also be used. It uses the
318 SHA-256 cryptographic hash function by default, but supports several
321 The output of the muxer consists of a line for each audio and video
324 @var{stream_index}, @var{packet_dts}, @var{packet_pts}, @var{packet_duration}, @var{packet_size}, @var{hash}
327 @var{hash} is a hexadecimal number representing the computed hash
331 @item hash @var{algorithm}
332 Use the cryptographic hash function specified by the string @var{algorithm}.
333 Supported values include @code{MD5}, @code{murmur3}, @code{RIPEMD128},
334 @code{RIPEMD160}, @code{RIPEMD256}, @code{RIPEMD320}, @code{SHA160},
335 @code{SHA224}, @code{SHA256} (default), @code{SHA512/224}, @code{SHA512/256},
336 @code{SHA384}, @code{SHA512}, @code{CRC32} and @code{adler32}.
342 To compute the SHA-256 hash of the audio and video frames in @file{INPUT},
343 converted to raw audio and video packets, and store it in the file
346 ffmpeg -i INPUT -f framehash out.sha256
349 To print the information to stdout, using the MD5 hash function, use
352 ffmpeg -i INPUT -f framehash -hash md5 -
355 See also the @ref{hash} muxer.
360 Per-packet MD5 testing format.
362 This is a variant of the @ref{framehash} muxer. Unlike that muxer,
363 it defaults to using the MD5 hash function.
367 To compute the MD5 hash of the audio and video frames in @file{INPUT},
368 converted to raw audio and video packets, and store it in the file
371 ffmpeg -i INPUT -f framemd5 out.md5
374 To print the information to stdout, use the command:
376 ffmpeg -i INPUT -f framemd5 -
379 See also the @ref{framehash} and @ref{md5} muxers.
386 It accepts the following options:
390 Set the number of times to loop the output. Use @code{-1} for no loop, @code{0}
391 for looping indefinitely (default).
394 Force the delay (expressed in centiseconds) after the last frame. Each frame
395 ends with a delay until the next frame. The default is @code{-1}, which is a
396 special value to tell the muxer to re-use the previous delay. In case of a
397 loop, you might want to customize this value to mark a pause for instance.
400 For example, to encode a gif looping 10 times, with a 5 seconds delay between
403 ffmpeg -i INPUT -loop 10 -final_delay 500 out.gif
406 Note 1: if you wish to extract the frames into separate GIF files, you need to
407 force the @ref{image2} muxer:
409 ffmpeg -i INPUT -c:v gif -f image2 "out%d.gif"
412 Note 2: the GIF format has a very large time base: the delay between two frames
413 can therefore not be smaller than one centi second.
420 This muxer computes and prints a cryptographic hash of all the input
421 audio and video frames. This can be used for equality checks without
422 having to do a complete binary comparison.
424 By default audio frames are converted to signed 16-bit raw audio and
425 video frames to raw video before computing the hash, but the output
426 of explicit conversions to other codecs can also be used. Timestamps
427 are ignored. It uses the SHA-256 cryptographic hash function by default,
428 but supports several other algorithms.
430 The output of the muxer consists of a single line of the form:
431 @var{algo}=@var{hash}, where @var{algo} is a short string representing
432 the hash function used, and @var{hash} is a hexadecimal number
433 representing the computed hash.
436 @item hash @var{algorithm}
437 Use the cryptographic hash function specified by the string @var{algorithm}.
438 Supported values include @code{MD5}, @code{murmur3}, @code{RIPEMD128},
439 @code{RIPEMD160}, @code{RIPEMD256}, @code{RIPEMD320}, @code{SHA160},
440 @code{SHA224}, @code{SHA256} (default), @code{SHA512/224}, @code{SHA512/256},
441 @code{SHA384}, @code{SHA512}, @code{CRC32} and @code{adler32}.
447 To compute the SHA-256 hash of the input converted to raw audio and
448 video, and store it in the file @file{out.sha256}:
450 ffmpeg -i INPUT -f hash out.sha256
453 To print an MD5 hash to stdout use the command:
455 ffmpeg -i INPUT -f hash -hash md5 -
458 See also the @ref{framehash} muxer.
463 Apple HTTP Live Streaming muxer that segments MPEG-TS according to
464 the HTTP Live Streaming (HLS) specification.
466 It creates a playlist file, and one or more segment files. The output filename
467 specifies the playlist filename.
469 By default, the muxer creates a file for each segment produced. These files
470 have the same name as the playlist, followed by a sequential number and a
473 Make sure to require a closed GOP when encoding and to set the GOP
474 size to fit your segment time constraint.
476 For example, to convert an input file with @command{ffmpeg}:
478 ffmpeg -i in.mkv -c:v h264 -flags +cgop -g 30 -hls_time 1 out.m3u8
480 This example will produce the playlist, @file{out.m3u8}, and segment files:
481 @file{out0.ts}, @file{out1.ts}, @file{out2.ts}, etc.
483 See also the @ref{segment} muxer, which provides a more generic and
484 flexible implementation of a segmenter, and can be used to perform HLS
489 This muxer supports the following options:
492 @item hls_init_time @var{seconds}
493 Set the initial target segment length in seconds. Default value is @var{0}.
494 Segment will be cut on the next key frame after this time has passed on the first m3u8 list.
495 After the initial playlist is filled @command{ffmpeg} will cut segments
496 at duration equal to @code{hls_time}
498 @item hls_time @var{seconds}
499 Set the target segment length in seconds. Default value is 2.
500 Segment will be cut on the next key frame after this time has passed.
502 @item hls_list_size @var{size}
503 Set the maximum number of playlist entries. If set to 0 the list file
504 will contain all the segments. Default value is 5.
506 @item hls_ts_options @var{options_list}
507 Set output format options using a :-separated list of key=value
508 parameters. Values containing @code{:} special characters must be
511 @item hls_wrap @var{wrap}
512 This is a deprecated option, you can use @code{hls_list_size}
513 and @code{hls_flags delete_segments} instead it
515 This option is useful to avoid to fill the disk with many segment
516 files, and limits the maximum number of segment files written to disk
520 @item hls_start_number_source
521 Start the playlist sequence number (@code{#EXT-X-MEDIA-SEQUENCE}) according to the specified source.
522 Unless @code{hls_flags single_file} is set, it also specifies source of starting sequence numbers of
523 segment and subtitle filenames. In any case, if @code{hls_flags append_list}
524 is set and read playlist sequence number is greater than the specified start sequence number,
525 then that value will be used as start value.
527 It accepts the following values:
531 @item generic (default)
532 Set the starting sequence numbers according to @var{start_number} option value.
535 The start number will be the seconds since epoch (1970-01-01 00:00:00)
538 The start number will be based on the current date/time as YYYYmmddHHMMSS. e.g. 20161231235759.
542 @item start_number @var{number}
543 Start the playlist sequence number (@code{#EXT-X-MEDIA-SEQUENCE}) from the specified @var{number}
544 when @var{hls_start_number_source} value is @var{generic}. (This is the default case.)
545 Unless @code{hls_flags single_file} is set, it also specifies starting sequence numbers of segment and subtitle filenames.
548 @item hls_allow_cache @var{allowcache}
549 Explicitly set whether the client MAY (1) or MUST NOT (0) cache media segments.
551 @item hls_base_url @var{baseurl}
552 Append @var{baseurl} to every entry in the playlist.
553 Useful to generate playlists with absolute paths.
555 Note that the playlist sequence number must be unique for each segment
556 and it is not to be confused with the segment filename sequence number
557 which can be cyclic, for example if the @option{wrap} option is
560 @item hls_segment_filename @var{filename}
561 Set the segment filename. Unless @code{hls_flags single_file} is set,
562 @var{filename} is used as a string format with the segment number:
564 ffmpeg -i in.nut -hls_segment_filename 'file%03d.ts' out.m3u8
566 This example will produce the playlist, @file{out.m3u8}, and segment files:
567 @file{file000.ts}, @file{file001.ts}, @file{file002.ts}, etc.
569 @var{filename} may contain full path or relative path specification,
570 but only the file name part without any path info will be contained in the m3u8 segment list.
571 Should a relative path be specified, the path of the created segment
572 files will be relative to the current working directory.
573 When use_localtime_mkdir is set, the whole expanded value of @var{filename} will be written into the m3u8 segment list.
577 Use strftime() on @var{filename} to expand the segment filename with localtime.
578 The segment number is also available in this mode, but to use it, you need to specify second_level_segment_index
579 hls_flag and %%d will be the specifier.
581 ffmpeg -i in.nut -use_localtime 1 -hls_segment_filename 'file-%Y%m%d-%s.ts' out.m3u8
583 This example will produce the playlist, @file{out.m3u8}, and segment files:
584 @file{file-20160215-1455569023.ts}, @file{file-20160215-1455569024.ts}, etc.
585 Note: On some systems/environments, the @code{%s} specifier is not available. See
586 @code{strftime()} documentation.
588 ffmpeg -i in.nut -use_localtime 1 -hls_flags second_level_segment_index -hls_segment_filename 'file-%Y%m%d-%%04d.ts' out.m3u8
590 This example will produce the playlist, @file{out.m3u8}, and segment files:
591 @file{file-20160215-0001.ts}, @file{file-20160215-0002.ts}, etc.
593 @item use_localtime_mkdir
594 Used together with -use_localtime, it will create all subdirectories which
595 is expanded in @var{filename}.
597 ffmpeg -i in.nut -use_localtime 1 -use_localtime_mkdir 1 -hls_segment_filename '%Y%m%d/file-%Y%m%d-%s.ts' out.m3u8
599 This example will create a directory 201560215 (if it does not exist), and then
600 produce the playlist, @file{out.m3u8}, and segment files:
601 @file{20160215/file-20160215-1455569023.ts}, @file{20160215/file-20160215-1455569024.ts}, etc.
604 ffmpeg -i in.nut -use_localtime 1 -use_localtime_mkdir 1 -hls_segment_filename '%Y/%m/%d/file-%Y%m%d-%s.ts' out.m3u8
606 This example will create a directory hierarchy 2016/02/15 (if any of them do not exist), and then
607 produce the playlist, @file{out.m3u8}, and segment files:
608 @file{2016/02/15/file-20160215-1455569023.ts}, @file{2016/02/15/file-20160215-1455569024.ts}, etc.
611 @item hls_key_info_file @var{key_info_file}
612 Use the information in @var{key_info_file} for segment encryption. The first
613 line of @var{key_info_file} specifies the key URI written to the playlist. The
614 key URL is used to access the encryption key during playback. The second line
615 specifies the path to the key file used to obtain the key during the encryption
616 process. The key file is read as a single packed array of 16 octets in binary
617 format. The optional third line specifies the initialization vector (IV) as a
618 hexadecimal string to be used instead of the segment sequence number (default)
619 for encryption. Changes to @var{key_info_file} will result in segment
620 encryption with the new key/IV and an entry in the playlist for the new key
621 URI/IV if @code{hls_flags periodic_rekey} is enabled.
623 Key info file format:
632 http://server/file.key
637 Example key file paths:
645 0123456789ABCDEF0123456789ABCDEF
648 Key info file example:
650 http://server/file.key
652 0123456789ABCDEF0123456789ABCDEF
655 Example shell script:
659 openssl rand 16 > file.key
660 echo $BASE_URL/file.key > file.keyinfo
661 echo file.key >> file.keyinfo
662 echo $(openssl rand -hex 16) >> file.keyinfo
663 ffmpeg -f lavfi -re -i testsrc -c:v h264 -hls_flags delete_segments \
664 -hls_key_info_file file.keyinfo out.m3u8
667 @item -hls_enc @var{enc}
668 Enable (1) or disable (0) the AES128 encryption.
669 When enabled every segment generated is encrypted and the encryption key
670 is saved as @var{playlist name}.key.
672 @item -hls_enc_key @var{key}
673 Hex-coded 16byte key to encrypt the segments, by default it
674 is randomly generated.
676 @item -hls_enc_key_url @var{keyurl}
677 If set, @var{keyurl} is prepended instead of @var{baseurl} to the key filename
680 @item -hls_enc_iv @var{iv}
681 Hex-coded 16byte initialization vector for every segment instead
682 of the autogenerated ones.
684 @item hls_segment_type @var{flags}
689 If this flag is set, the hls segment files will format to mpegts.
690 the mpegts files is used in all hls versions.
693 If this flag is set, the hls segment files will format to fragment mp4 looks like dash.
694 the fmp4 files is used in hls after version 7.
698 @item hls_fmp4_init_filename @var{filename}
699 set filename to the fragment files header file, default filename is @file{init.mp4}.
701 @item hls_flags @var{flags}
706 If this flag is set, the muxer will store all segments in a single MPEG-TS
707 file, and will use byte ranges in the playlist. HLS playlists generated with
708 this way will have the version number 4.
711 ffmpeg -i in.nut -hls_flags single_file out.m3u8
713 Will produce the playlist, @file{out.m3u8}, and a single segment file,
716 @item delete_segments
717 Segment files removed from the playlist are deleted after a period of time
718 equal to the duration of the segment plus the duration of the playlist.
721 Append new segments into the end of old segment list,
722 and remove the @code{#EXT-X-ENDLIST} from the old segment list.
724 @item round_durations
725 Round the duration info in the playlist file segment info to integer
726 values, instead of using floating point.
729 Add the @code{#EXT-X-DISCONTINUITY} tag to the playlist, before the
730 first segment's information.
733 Do not append the @code{EXT-X-ENDLIST} tag at the end of the playlist.
736 The file specified by @code{hls_key_info_file} will be checked periodically and
737 detect updates to the encryption info. Be sure to replace this file atomically,
738 including the file containing the AES encryption key.
740 @item independent_segments
741 Add the @code{#EXT-X-INDEPENDENT-SEGMENTS} to playlists that has video segments
742 and when all the segments of that playlist are guaranteed to start with a Key frame.
745 Allow segments to start on frames other than keyframes. This improves
746 behavior on some players when the time between keyframes is inconsistent,
747 but may make things worse on others, and can cause some oddities during
748 seeking. This flag should be used with the @code{hls_time} option.
750 @item program_date_time
751 Generate @code{EXT-X-PROGRAM-DATE-TIME} tags.
753 @item second_level_segment_index
754 Makes it possible to use segment indexes as %%d in hls_segment_filename expression
755 besides date/time values when use_localtime is on.
756 To get fixed width numbers with trailing zeroes, %%0xd format is available where x is the required width.
758 @item second_level_segment_size
759 Makes it possible to use segment sizes (counted in bytes) as %%s in hls_segment_filename
760 expression besides date/time values when use_localtime is on.
761 To get fixed width numbers with trailing zeroes, %%0xs format is available where x is the required width.
763 @item second_level_segment_duration
764 Makes it possible to use segment duration (calculated in microseconds) as %%t in hls_segment_filename
765 expression besides date/time values when use_localtime is on.
766 To get fixed width numbers with trailing zeroes, %%0xt format is available where x is the required width.
769 ffmpeg -i sample.mpeg \
770 -f hls -hls_time 3 -hls_list_size 5 \
771 -hls_flags second_level_segment_index+second_level_segment_size+second_level_segment_duration \
772 -use_localtime 1 -use_localtime_mkdir 1 -hls_segment_filename "segment_%Y%m%d%H%M%S_%%04d_%%08s_%%013t.ts" stream.m3u8
774 This will produce segments like this:
775 @file{segment_20170102194334_0003_00122200_0000003000000.ts}, @file{segment_20170102194334_0004_00120072_0000003000000.ts} etc.
778 Write segment data to filename.tmp and rename to filename only once the segment is complete. A webserver
779 serving up segments can be configured to reject requests to *.tmp to prevent access to in-progress segments
780 before they have been added to the m3u8 playlist.
784 @item hls_playlist_type event
785 Emit @code{#EXT-X-PLAYLIST-TYPE:EVENT} in the m3u8 header. Forces
786 @option{hls_list_size} to 0; the playlist can only be appended to.
788 @item hls_playlist_type vod
789 Emit @code{#EXT-X-PLAYLIST-TYPE:VOD} in the m3u8 header. Forces
790 @option{hls_list_size} to 0; the playlist must not change.
793 Use the given HTTP method to create the hls files.
795 ffmpeg -re -i in.ts -f hls -method PUT http://example.com/live/out.m3u8
797 This example will upload all the mpegts segment files to the HTTP
798 server using the HTTP PUT method, and update the m3u8 files every
799 @code{refresh} times using the same method.
800 Note that the HTTP server must support the given method for uploading
803 @item http_user_agent
804 Override User-Agent field in HTTP header. Applicable only for HTTP output.
807 Map string which specifies how to group the audio, video and subtitle streams
808 into different variant streams. The variant stream groups are separated
810 Expected string format is like this "a:0,v:0 a:1,v:1 ....". Here a:, v:, s: are
811 the keys to specify audio, video and subtitle streams respectively.
812 Allowed values are 0 to 9 (limited just based on practical usage).
815 ffmpeg -re -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k -b:a:1 32k \
816 -map 0:v -map 0:a -map 0:v -map 0:a -f hls -var_stream_map "v:0,a:0 v:1,a:1" \
817 http://example.com/live/out.m3u8
819 This example creates two hls variant streams. The first variant stream will
820 contain video stream of bitrate 1000k and audio stream of bitrate 64k and the
821 second variant stream will contain video stream of bitrate 256k and audio
822 stream of bitrate 32k. Here, two media playlist with file names out_1.m3u8 and
823 out_2.m3u8 will be created.
825 ffmpeg -re -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k \
826 -map 0:v -map 0:a -map 0:v -f hls -var_stream_map "v:0 a:0 v:1" \
827 http://example.com/live/out.m3u8
829 This example creates three hls variant streams. The first variant stream will
830 be a video only stream with video bitrate 1000k, the second variant stream will
831 be an audio only stream with bitrate 64k and the third variant stream will be a
832 video only stream with bitrate 256k. Here, three media playlist with file names
833 out_1.m3u8, out_2.m3u8 and out_3.m3u8 will be created.
835 By default, a single hls variant containing all the encoded streams is created.
838 Create HLS master playlist with the given name.
841 ffmpeg -re -i in.ts -f hls -master_pl_name master.m3u8 http://example.com/live/out.m3u8
843 This example creates HLS master playlist with name master.m3u8 and it is
844 published at http://example.com/live/
846 @item master_pl_publish_rate
847 Publish master play list repeatedly every after specified number of segment intervals.
850 ffmpeg -re -i in.ts -f hls -master_pl_name master.m3u8 \
851 -hls_time 2 -master_pl_publish_rate 30 http://example.com/live/out.m3u8
854 This example creates HLS master playlist with name master.m3u8 and keep
855 publishing it repeatedly every after 30 segments i.e. every after 60s.
864 Microsoft's icon file format (ICO) has some strict limitations that should be noted:
868 Size cannot exceed 256 pixels in any dimension
871 Only BMP and PNG images can be stored
874 If a BMP image is used, it must be one of the following pixel formats:
876 BMP Bit Depth FFmpeg Pixel Format
886 If a BMP image is used, it must use the BITMAPINFOHEADER DIB header
889 If a PNG image is used, it must use the rgba pixel format
897 The image file muxer writes video frames to image files.
899 The output filenames are specified by a pattern, which can be used to
900 produce sequentially numbered series of files.
901 The pattern may contain the string "%d" or "%0@var{N}d", this string
902 specifies the position of the characters representing a numbering in
903 the filenames. If the form "%0@var{N}d" is used, the string
904 representing the number in each filename is 0-padded to @var{N}
905 digits. The literal character '%' can be specified in the pattern with
908 If the pattern contains "%d" or "%0@var{N}d", the first filename of
909 the file list specified will contain the number 1, all the following
910 numbers will be sequential.
912 The pattern may contain a suffix which is used to automatically
913 determine the format of the image files to write.
915 For example the pattern "img-%03d.bmp" will specify a sequence of
916 filenames of the form @file{img-001.bmp}, @file{img-002.bmp}, ...,
917 @file{img-010.bmp}, etc.
918 The pattern "img%%-%d.jpg" will specify a sequence of filenames of the
919 form @file{img%-1.jpg}, @file{img%-2.jpg}, ..., @file{img%-10.jpg},
924 The following example shows how to use @command{ffmpeg} for creating a
925 sequence of files @file{img-001.jpeg}, @file{img-002.jpeg}, ...,
926 taking one image every second from the input video:
928 ffmpeg -i in.avi -vsync cfr -r 1 -f image2 'img-%03d.jpeg'
931 Note that with @command{ffmpeg}, if the format is not specified with the
932 @code{-f} option and the output filename specifies an image file
933 format, the image2 muxer is automatically selected, so the previous
934 command can be written as:
936 ffmpeg -i in.avi -vsync cfr -r 1 'img-%03d.jpeg'
939 Note also that the pattern must not necessarily contain "%d" or
940 "%0@var{N}d", for example to create a single image file
941 @file{img.jpeg} from the start of the input video you can employ the command:
943 ffmpeg -i in.avi -f image2 -frames:v 1 img.jpeg
946 The @option{strftime} option allows you to expand the filename with
947 date and time information. Check the documentation of
948 the @code{strftime()} function for the syntax.
950 For example to generate image files from the @code{strftime()}
951 "%Y-%m-%d_%H-%M-%S" pattern, the following @command{ffmpeg} command
954 ffmpeg -f v4l2 -r 1 -i /dev/video0 -f image2 -strftime 1 "%Y-%m-%d_%H-%M-%S.jpg"
957 You can set the file name with current frame's PTS:
959 ffmpeg -f v4l2 -r 1 -i /dev/video0 -copyts -f image2 -frame_pts true %d.jpg"
966 If set to 1, expand the filename with pts from pkt->pts.
970 Start the sequence from the specified number. Default value is 1.
973 If set to 1, the filename will always be interpreted as just a
974 filename, not a pattern, and the corresponding file will be continuously
975 overwritten with new images. Default value is 0.
978 If set to 1, expand the filename with date and time information from
979 @code{strftime()}. Default value is 0.
982 The image muxer supports the .Y.U.V image file format. This format is
983 special in that that each image frame consists of three files, for
984 each of the YUV420P components. To read or write this image file format,
985 specify the name of the '.Y' file. The muxer will automatically open the
986 '.U' and '.V' files as required.
990 Matroska container muxer.
992 This muxer implements the matroska and webm container specs.
996 The recognized metadata settings in this muxer are:
1000 Set title name provided to a single track.
1003 Specify the language of the track in the Matroska languages form.
1005 The language can be either the 3 letters bibliographic ISO-639-2 (ISO
1006 639-2/B) form (like "fre" for French), or a language code mixed with a
1007 country code for specialities in languages (like "fre-ca" for Canadian
1011 Set stereo 3D video layout of two views in a single video track.
1013 The following values are recognized:
1018 Both views are arranged side by side, Left-eye view is on the left
1020 Both views are arranged in top-bottom orientation, Left-eye view is at bottom
1022 Both views are arranged in top-bottom orientation, Left-eye view is on top
1023 @item checkerboard_rl
1024 Each view is arranged in a checkerboard interleaved pattern, Left-eye view being first
1025 @item checkerboard_lr
1026 Each view is arranged in a checkerboard interleaved pattern, Right-eye view being first
1027 @item row_interleaved_rl
1028 Each view is constituted by a row based interleaving, Right-eye view is first row
1029 @item row_interleaved_lr
1030 Each view is constituted by a row based interleaving, Left-eye view is first row
1031 @item col_interleaved_rl
1032 Both views are arranged in a column based interleaving manner, Right-eye view is first column
1033 @item col_interleaved_lr
1034 Both views are arranged in a column based interleaving manner, Left-eye view is first column
1035 @item anaglyph_cyan_red
1036 All frames are in anaglyph format viewable through red-cyan filters
1038 Both views are arranged side by side, Right-eye view is on the left
1039 @item anaglyph_green_magenta
1040 All frames are in anaglyph format viewable through green-magenta filters
1042 Both eyes laced in one Block, Left-eye view is first
1044 Both eyes laced in one Block, Right-eye view is first
1048 For example a 3D WebM clip can be created using the following command line:
1050 ffmpeg -i sample_left_right_clip.mpg -an -c:v libvpx -metadata stereo_mode=left_right -y stereo_clip.webm
1055 This muxer supports the following options:
1058 @item reserve_index_space
1059 By default, this muxer writes the index for seeking (called cues in Matroska
1060 terms) at the end of the file, because it cannot know in advance how much space
1061 to leave for the index at the beginning of the file. However for some use cases
1062 -- e.g. streaming where seeking is possible but slow -- it is useful to put the
1063 index at the beginning of the file.
1065 If this option is set to a non-zero value, the muxer will reserve a given amount
1066 of space in the file header and then try to write the cues there when the muxing
1067 finishes. If the available space does not suffice, muxing will fail. A safe size
1068 for most use cases should be about 50kB per hour of video.
1070 Note that cues are only written if the output is seekable and this option will
1071 have no effect if it is not.
1079 This is a variant of the @ref{hash} muxer. Unlike that muxer, it
1080 defaults to using the MD5 hash function.
1082 @subsection Examples
1084 To compute the MD5 hash of the input converted to raw
1085 audio and video, and store it in the file @file{out.md5}:
1087 ffmpeg -i INPUT -f md5 out.md5
1090 You can print the MD5 to stdout with the command:
1092 ffmpeg -i INPUT -f md5 -
1095 See also the @ref{hash} and @ref{framemd5} muxers.
1097 @section mov, mp4, ismv
1099 MOV/MP4/ISMV (Smooth Streaming) muxer.
1101 The mov/mp4/ismv muxer supports fragmentation. Normally, a MOV/MP4
1102 file has all the metadata about all packets stored in one location
1103 (written at the end of the file, it can be moved to the start for
1104 better playback by adding @var{faststart} to the @var{movflags}, or
1105 using the @command{qt-faststart} tool). A fragmented
1106 file consists of a number of fragments, where packets and metadata
1107 about these packets are stored together. Writing a fragmented
1108 file has the advantage that the file is decodable even if the
1109 writing is interrupted (while a normal MOV/MP4 is undecodable if
1110 it is not properly finished), and it requires less memory when writing
1111 very long files (since writing normal MOV/MP4 files stores info about
1112 every single packet in memory until the file is closed). The downside
1113 is that it is less compatible with other applications.
1117 Fragmentation is enabled by setting one of the AVOptions that define
1118 how to cut the file into fragments:
1121 @item -moov_size @var{bytes}
1122 Reserves space for the moov atom at the beginning of the file instead of placing the
1123 moov atom at the end. If the space reserved is insufficient, muxing will fail.
1124 @item -movflags frag_keyframe
1125 Start a new fragment at each video keyframe.
1126 @item -frag_duration @var{duration}
1127 Create fragments that are @var{duration} microseconds long.
1128 @item -frag_size @var{size}
1129 Create fragments that contain up to @var{size} bytes of payload data.
1130 @item -movflags frag_custom
1131 Allow the caller to manually choose when to cut fragments, by
1132 calling @code{av_write_frame(ctx, NULL)} to write a fragment with
1133 the packets written so far. (This is only useful with other
1134 applications integrating libavformat, not from @command{ffmpeg}.)
1135 @item -min_frag_duration @var{duration}
1136 Don't create fragments that are shorter than @var{duration} microseconds long.
1139 If more than one condition is specified, fragments are cut when
1140 one of the specified conditions is fulfilled. The exception to this is
1141 @code{-min_frag_duration}, which has to be fulfilled for any of the other
1142 conditions to apply.
1144 Additionally, the way the output file is written can be adjusted
1145 through a few other options:
1148 @item -movflags empty_moov
1149 Write an initial moov atom directly at the start of the file, without
1150 describing any samples in it. Generally, an mdat/moov pair is written
1151 at the start of the file, as a normal MOV/MP4 file, containing only
1152 a short portion of the file. With this option set, there is no initial
1153 mdat atom, and the moov atom only describes the tracks but has
1156 This option is implicitly set when writing ismv (Smooth Streaming) files.
1157 @item -movflags separate_moof
1158 Write a separate moof (movie fragment) atom for each track. Normally,
1159 packets for all tracks are written in a moof atom (which is slightly
1160 more efficient), but with this option set, the muxer writes one moof/mdat
1161 pair for each track, making it easier to separate tracks.
1163 This option is implicitly set when writing ismv (Smooth Streaming) files.
1164 @item -movflags faststart
1165 Run a second pass moving the index (moov atom) to the beginning of the file.
1166 This operation can take a while, and will not work in various situations such
1167 as fragmented output, thus it is not enabled by default.
1168 @item -movflags rtphint
1169 Add RTP hinting tracks to the output file.
1170 @item -movflags disable_chpl
1171 Disable Nero chapter markers (chpl atom). Normally, both Nero chapters
1172 and a QuickTime chapter track are written to the file. With this option
1173 set, only the QuickTime chapter track will be written. Nero chapters can
1174 cause failures when the file is reprocessed with certain tagging programs, like
1175 mp3Tag 2.61a and iTunes 11.3, most likely other versions are affected as well.
1176 @item -movflags omit_tfhd_offset
1177 Do not write any absolute base_data_offset in tfhd atoms. This avoids
1178 tying fragments to absolute byte positions in the file/streams.
1179 @item -movflags default_base_moof
1180 Similarly to the omit_tfhd_offset, this flag avoids writing the
1181 absolute base_data_offset field in tfhd atoms, but does so by using
1182 the new default-base-is-moof flag instead. This flag is new from
1183 14496-12:2012. This may make the fragments easier to parse in certain
1184 circumstances (avoiding basing track fragment location calculations
1185 on the implicit end of the previous track fragment).
1187 Specify @code{on} to force writing a timecode track, @code{off} to disable it
1188 and @code{auto} to write a timecode track only for mov and mp4 output (default).
1189 @item -movflags negative_cts_offsets
1190 Enables utilization of version 1 of the CTTS box, in which the CTS offsets can
1191 be negative. This enables the initial sample to have DTS/CTS of zero, and
1192 reduces the need for edit lists for some cases such as video tracks with
1193 B-frames. Additionally, eases conformance with the DASH-IF interoperability
1199 Smooth Streaming content can be pushed in real time to a publishing
1200 point on IIS with this muxer. Example:
1202 ffmpeg -re @var{<normal input/transcoding options>} -movflags isml+frag_keyframe -f ismv http://server/publishingpoint.isml/Streams(Encoder1)
1205 @subsection Audible AAX
1207 Audible AAX files are encrypted M4B files, and they can be decrypted by specifying a 4 byte activation secret.
1209 ffmpeg -activation_bytes 1CEB00DA -i test.aax -vn -c:a copy output.mp4
1214 The MP3 muxer writes a raw MP3 stream with the following optional features:
1217 An ID3v2 metadata header at the beginning (enabled by default). Versions 2.3 and
1218 2.4 are supported, the @code{id3v2_version} private option controls which one is
1219 used (3 or 4). Setting @code{id3v2_version} to 0 disables the ID3v2 header
1222 The muxer supports writing attached pictures (APIC frames) to the ID3v2 header.
1223 The pictures are supplied to the muxer in form of a video stream with a single
1224 packet. There can be any number of those streams, each will correspond to a
1225 single APIC frame. The stream metadata tags @var{title} and @var{comment} map
1226 to APIC @var{description} and @var{picture type} respectively. See
1227 @url{http://id3.org/id3v2.4.0-frames} for allowed picture types.
1229 Note that the APIC frames must be written at the beginning, so the muxer will
1230 buffer the audio frames until it gets all the pictures. It is therefore advised
1231 to provide the pictures as soon as possible to avoid excessive buffering.
1234 A Xing/LAME frame right after the ID3v2 header (if present). It is enabled by
1235 default, but will be written only if the output is seekable. The
1236 @code{write_xing} private option can be used to disable it. The frame contains
1237 various information that may be useful to the decoder, like the audio duration
1241 A legacy ID3v1 tag at the end of the file (disabled by default). It may be
1242 enabled with the @code{write_id3v1} private option, but as its capabilities are
1243 very limited, its usage is not recommended.
1248 Write an mp3 with an ID3v2.3 header and an ID3v1 footer:
1250 ffmpeg -i INPUT -id3v2_version 3 -write_id3v1 1 out.mp3
1253 To attach a picture to an mp3 file select both the audio and the picture stream
1256 ffmpeg -i input.mp3 -i cover.png -c copy -map 0 -map 1
1257 -metadata:s:v title="Album cover" -metadata:s:v comment="Cover (Front)" out.mp3
1260 Write a "clean" MP3 without any extra features:
1262 ffmpeg -i input.wav -write_xing 0 -id3v2_version 0 out.mp3
1267 MPEG transport stream muxer.
1269 This muxer implements ISO 13818-1 and part of ETSI EN 300 468.
1271 The recognized metadata settings in mpegts muxer are @code{service_provider}
1272 and @code{service_name}. If they are not set the default for
1273 @code{service_provider} is @samp{FFmpeg} and the default for
1274 @code{service_name} is @samp{Service01}.
1278 The muxer options are:
1281 @item mpegts_transport_stream_id @var{integer}
1282 Set the @samp{transport_stream_id}. This identifies a transponder in DVB.
1283 Default is @code{0x0001}.
1285 @item mpegts_original_network_id @var{integer}
1286 Set the @samp{original_network_id}. This is unique identifier of a
1287 network in DVB. Its main use is in the unique identification of a service
1288 through the path @samp{Original_Network_ID, Transport_Stream_ID}. Default
1291 @item mpegts_service_id @var{integer}
1292 Set the @samp{service_id}, also known as program in DVB. Default is
1295 @item mpegts_service_type @var{integer}
1296 Set the program @samp{service_type}. Default is @code{digital_tv}.
1297 Accepts the following options:
1300 Any hexdecimal value between @code{0x01} to @code{0xff} as defined in
1305 Digital Radio service.
1308 @item advanced_codec_digital_radio
1309 Advanced Codec Digital Radio service.
1310 @item mpeg2_digital_hdtv
1311 MPEG2 Digital HDTV service.
1312 @item advanced_codec_digital_sdtv
1313 Advanced Codec Digital SDTV service.
1314 @item advanced_codec_digital_hdtv
1315 Advanced Codec Digital HDTV service.
1318 @item mpegts_pmt_start_pid @var{integer}
1319 Set the first PID for PMT. Default is @code{0x1000}. Max is @code{0x1f00}.
1321 @item mpegts_start_pid @var{integer}
1322 Set the first PID for data packets. Default is @code{0x0100}. Max is
1325 @item mpegts_m2ts_mode @var{boolean}
1326 Enable m2ts mode if set to @code{1}. Default value is @code{-1} which
1329 @item muxrate @var{integer}
1330 Set a constant muxrate. Default is VBR.
1332 @item pes_payload_size @var{integer}
1333 Set minimum PES packet payload in bytes. Default is @code{2930}.
1335 @item mpegts_flags @var{flags}
1336 Set mpegts flags. Accepts the following options:
1338 @item resend_headers
1339 Reemit PAT/PMT before writing the next packet.
1341 Use LATM packetization for AAC.
1342 @item pat_pmt_at_frames
1343 Reemit PAT and PMT at each video frame.
1345 Conform to System B (DVB) instead of System A (ATSC).
1346 @item initial_discontinuity
1347 Mark the initial packet of each stream as discontinuity.
1350 @item resend_headers @var{integer}
1351 Reemit PAT/PMT before writing the next packet. This option is deprecated:
1352 use @option{mpegts_flags} instead.
1354 @item mpegts_copyts @var{boolean}
1355 Preserve original timestamps, if value is set to @code{1}. Default value
1356 is @code{-1}, which results in shifting timestamps so that they start from 0.
1358 @item omit_video_pes_length @var{boolean}
1359 Omit the PES packet length for video packets. Default is @code{1} (true).
1361 @item pcr_period @var{integer}
1362 Override the default PCR retransmission time in milliseconds. Ignored if
1363 variable muxrate is selected. Default is @code{20}.
1365 @item pat_period @var{double}
1366 Maximum time in seconds between PAT/PMT tables.
1368 @item sdt_period @var{double}
1369 Maximum time in seconds between SDT tables.
1371 @item tables_version @var{integer}
1372 Set PAT, PMT and SDT version (default @code{0}, valid values are from 0 to 31, inclusively).
1373 This option allows updating stream structure so that standard consumer may
1374 detect the change. To do so, reopen output @code{AVFormatContext} (in case of API
1375 usage) or restart @command{ffmpeg} instance, cyclically changing
1376 @option{tables_version} value:
1379 ffmpeg -i source1.ts -codec copy -f mpegts -tables_version 0 udp://1.1.1.1:1111
1380 ffmpeg -i source2.ts -codec copy -f mpegts -tables_version 1 udp://1.1.1.1:1111
1382 ffmpeg -i source3.ts -codec copy -f mpegts -tables_version 31 udp://1.1.1.1:1111
1383 ffmpeg -i source1.ts -codec copy -f mpegts -tables_version 0 udp://1.1.1.1:1111
1384 ffmpeg -i source2.ts -codec copy -f mpegts -tables_version 1 udp://1.1.1.1:1111
1392 ffmpeg -i file.mpg -c copy \
1393 -mpegts_original_network_id 0x1122 \
1394 -mpegts_transport_stream_id 0x3344 \
1395 -mpegts_service_id 0x5566 \
1396 -mpegts_pmt_start_pid 0x1500 \
1397 -mpegts_start_pid 0x150 \
1398 -metadata service_provider="Some provider" \
1399 -metadata service_name="Some Channel" \
1403 @section mxf, mxf_d10
1409 The muxer options are:
1412 @item store_user_comments @var{bool}
1413 Set if user comments should be stored if available or never.
1414 IRT D-10 does not allow user comments. The default is thus to write them for
1415 mxf but not for mxf_d10
1422 This muxer does not generate any output file, it is mainly useful for
1423 testing or benchmarking purposes.
1425 For example to benchmark decoding with @command{ffmpeg} you can use the
1428 ffmpeg -benchmark -i INPUT -f null out.null
1431 Note that the above command does not read or write the @file{out.null}
1432 file, but specifying the output file is required by the @command{ffmpeg}
1435 Alternatively you can write the command as:
1437 ffmpeg -benchmark -i INPUT -f null -
1443 @item -syncpoints @var{flags}
1444 Change the syncpoint usage in nut:
1446 @item @var{default} use the normal low-overhead seeking aids.
1447 @item @var{none} do not use the syncpoints at all, reducing the overhead but making the stream non-seekable;
1448 Use of this option is not recommended, as the resulting files are very damage
1449 sensitive and seeking is not possible. Also in general the overhead from
1450 syncpoints is negligible. Note, -@code{write_index} 0 can be used to disable
1451 all growing data tables, allowing to mux endless streams with limited memory
1452 and without these disadvantages.
1453 @item @var{timestamped} extend the syncpoint with a wallclock field.
1455 The @var{none} and @var{timestamped} flags are experimental.
1456 @item -write_index @var{bool}
1457 Write index at the end, the default is to write an index.
1461 ffmpeg -i INPUT -f_strict experimental -syncpoints none - | processor
1466 Ogg container muxer.
1469 @item -page_duration @var{duration}
1470 Preferred page duration, in microseconds. The muxer will attempt to create
1471 pages that are approximately @var{duration} microseconds long. This allows the
1472 user to compromise between seek granularity and container overhead. The default
1473 is 1 second. A value of 0 will fill all segments, making pages as large as
1474 possible. A value of 1 will effectively use 1 packet-per-page in most
1475 situations, giving a small seek granularity at the cost of additional container
1477 @item -serial_offset @var{value}
1478 Serial value from which to set the streams serial number.
1479 Setting it to different and sufficiently large values ensures that the produced
1480 ogg files can be safely chained.
1485 @section segment, stream_segment, ssegment
1487 Basic stream segmenter.
1489 This muxer outputs streams to a number of separate files of nearly
1490 fixed duration. Output filename pattern can be set in a fashion
1491 similar to @ref{image2}, or by using a @code{strftime} template if
1492 the @option{strftime} option is enabled.
1494 @code{stream_segment} is a variant of the muxer used to write to
1495 streaming output formats, i.e. which do not require global headers,
1496 and is recommended for outputting e.g. to MPEG transport stream segments.
1497 @code{ssegment} is a shorter alias for @code{stream_segment}.
1499 Every segment starts with a keyframe of the selected reference stream,
1500 which is set through the @option{reference_stream} option.
1502 Note that if you want accurate splitting for a video file, you need to
1503 make the input key frames correspond to the exact splitting times
1504 expected by the segmenter, or the segment muxer will start the new
1505 segment with the key frame found next after the specified start
1508 The segment muxer works best with a single constant frame rate video.
1510 Optionally it can generate a list of the created segments, by setting
1511 the option @var{segment_list}. The list type is specified by the
1512 @var{segment_list_type} option. The entry filenames in the segment
1513 list are set by default to the basename of the corresponding segment
1516 See also the @ref{hls} muxer, which provides a more specific
1517 implementation for HLS segmentation.
1521 The segment muxer supports the following options:
1524 @item increment_tc @var{1|0}
1525 if set to @code{1}, increment timecode between each segment
1526 If this is selected, the input need to have
1527 a timecode in the first video stream. Default value is
1530 @item reference_stream @var{specifier}
1531 Set the reference stream, as specified by the string @var{specifier}.
1532 If @var{specifier} is set to @code{auto}, the reference is chosen
1533 automatically. Otherwise it must be a stream specifier (see the ``Stream
1534 specifiers'' chapter in the ffmpeg manual) which specifies the
1535 reference stream. The default value is @code{auto}.
1537 @item segment_format @var{format}
1538 Override the inner container format, by default it is guessed by the filename
1541 @item segment_format_options @var{options_list}
1542 Set output format options using a :-separated list of key=value
1543 parameters. Values containing the @code{:} special character must be
1546 @item segment_list @var{name}
1547 Generate also a listfile named @var{name}. If not specified no
1548 listfile is generated.
1550 @item segment_list_flags @var{flags}
1551 Set flags affecting the segment list generation.
1553 It currently supports the following flags:
1556 Allow caching (only affects M3U8 list files).
1559 Allow live-friendly file generation.
1562 @item segment_list_size @var{size}
1563 Update the list file so that it contains at most @var{size}
1564 segments. If 0 the list file will contain all the segments. Default
1567 @item segment_list_entry_prefix @var{prefix}
1568 Prepend @var{prefix} to each entry. Useful to generate absolute paths.
1569 By default no prefix is applied.
1571 @item segment_list_type @var{type}
1572 Select the listing format.
1574 The following values are recognized:
1577 Generate a flat list for the created segments, one segment per line.
1580 Generate a list for the created segments, one segment per line,
1581 each line matching the format (comma-separated values):
1583 @var{segment_filename},@var{segment_start_time},@var{segment_end_time}
1586 @var{segment_filename} is the name of the output file generated by the
1587 muxer according to the provided pattern. CSV escaping (according to
1588 RFC4180) is applied if required.
1590 @var{segment_start_time} and @var{segment_end_time} specify
1591 the segment start and end time expressed in seconds.
1593 A list file with the suffix @code{".csv"} or @code{".ext"} will
1594 auto-select this format.
1596 @samp{ext} is deprecated in favor or @samp{csv}.
1599 Generate an ffconcat file for the created segments. The resulting file
1600 can be read using the FFmpeg @ref{concat} demuxer.
1602 A list file with the suffix @code{".ffcat"} or @code{".ffconcat"} will
1603 auto-select this format.
1606 Generate an extended M3U8 file, version 3, compliant with
1607 @url{http://tools.ietf.org/id/draft-pantos-http-live-streaming}.
1609 A list file with the suffix @code{".m3u8"} will auto-select this format.
1612 If not specified the type is guessed from the list file name suffix.
1614 @item segment_time @var{time}
1615 Set segment duration to @var{time}, the value must be a duration
1616 specification. Default value is "2". See also the
1617 @option{segment_times} option.
1619 Note that splitting may not be accurate, unless you force the
1620 reference stream key-frames at the given time. See the introductory
1621 notice and the examples below.
1623 @item segment_atclocktime @var{1|0}
1624 If set to "1" split at regular clock time intervals starting from 00:00
1625 o'clock. The @var{time} value specified in @option{segment_time} is
1626 used for setting the length of the splitting interval.
1628 For example with @option{segment_time} set to "900" this makes it possible
1629 to create files at 12:00 o'clock, 12:15, 12:30, etc.
1631 Default value is "0".
1633 @item segment_clocktime_offset @var{duration}
1634 Delay the segment splitting times with the specified duration when using
1635 @option{segment_atclocktime}.
1637 For example with @option{segment_time} set to "900" and
1638 @option{segment_clocktime_offset} set to "300" this makes it possible to
1639 create files at 12:05, 12:20, 12:35, etc.
1641 Default value is "0".
1643 @item segment_clocktime_wrap_duration @var{duration}
1644 Force the segmenter to only start a new segment if a packet reaches the muxer
1645 within the specified duration after the segmenting clock time. This way you
1646 can make the segmenter more resilient to backward local time jumps, such as
1647 leap seconds or transition to standard time from daylight savings time.
1649 Default is the maximum possible duration which means starting a new segment
1650 regardless of the elapsed time since the last clock time.
1652 @item segment_time_delta @var{delta}
1653 Specify the accuracy time when selecting the start time for a
1654 segment, expressed as a duration specification. Default value is "0".
1656 When delta is specified a key-frame will start a new segment if its
1657 PTS satisfies the relation:
1659 PTS >= start_time - time_delta
1662 This option is useful when splitting video content, which is always
1663 split at GOP boundaries, in case a key frame is found just before the
1664 specified split time.
1666 In particular may be used in combination with the @file{ffmpeg} option
1667 @var{force_key_frames}. The key frame times specified by
1668 @var{force_key_frames} may not be set accurately because of rounding
1669 issues, with the consequence that a key frame time may result set just
1670 before the specified time. For constant frame rate videos a value of
1671 1/(2*@var{frame_rate}) should address the worst case mismatch between
1672 the specified time and the time set by @var{force_key_frames}.
1674 @item segment_times @var{times}
1675 Specify a list of split points. @var{times} contains a list of comma
1676 separated duration specifications, in increasing order. See also
1677 the @option{segment_time} option.
1679 @item segment_frames @var{frames}
1680 Specify a list of split video frame numbers. @var{frames} contains a
1681 list of comma separated integer numbers, in increasing order.
1683 This option specifies to start a new segment whenever a reference
1684 stream key frame is found and the sequential number (starting from 0)
1685 of the frame is greater or equal to the next value in the list.
1687 @item segment_wrap @var{limit}
1688 Wrap around segment index once it reaches @var{limit}.
1690 @item segment_start_number @var{number}
1691 Set the sequence number of the first segment. Defaults to @code{0}.
1693 @item strftime @var{1|0}
1694 Use the @code{strftime} function to define the name of the new
1695 segments to write. If this is selected, the output segment name must
1696 contain a @code{strftime} function template. Default value is
1699 @item break_non_keyframes @var{1|0}
1700 If enabled, allow segments to start on frames other than keyframes. This
1701 improves behavior on some players when the time between keyframes is
1702 inconsistent, but may make things worse on others, and can cause some oddities
1703 during seeking. Defaults to @code{0}.
1705 @item reset_timestamps @var{1|0}
1706 Reset timestamps at the beginning of each segment, so that each segment
1707 will start with near-zero timestamps. It is meant to ease the playback
1708 of the generated segments. May not work with some combinations of
1709 muxers/codecs. It is set to @code{0} by default.
1711 @item initial_offset @var{offset}
1712 Specify timestamp offset to apply to the output packet timestamps. The
1713 argument must be a time duration specification, and defaults to 0.
1715 @item write_empty_segments @var{1|0}
1716 If enabled, write an empty segment if there are no packets during the period a
1717 segment would usually span. Otherwise, the segment will be filled with the next
1718 packet written. Defaults to @code{0}.
1721 Make sure to require a closed GOP when encoding and to set the GOP
1722 size to fit your segment time constraint.
1724 @subsection Examples
1728 Remux the content of file @file{in.mkv} to a list of segments
1729 @file{out-000.nut}, @file{out-001.nut}, etc., and write the list of
1730 generated segments to @file{out.list}:
1732 ffmpeg -i in.mkv -codec hevc -flags +cgop -g 60 -map 0 -f segment -segment_list out.list out%03d.nut
1736 Segment input and set output format options for the output segments:
1738 ffmpeg -i in.mkv -f segment -segment_time 10 -segment_format_options movflags=+faststart out%03d.mp4
1742 Segment the input file according to the split points specified by the
1743 @var{segment_times} option:
1745 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
1749 Use the @command{ffmpeg} @option{force_key_frames}
1750 option to force key frames in the input at the specified location, together
1751 with the segment option @option{segment_time_delta} to account for
1752 possible roundings operated when setting key frame times.
1754 ffmpeg -i in.mkv -force_key_frames 1,2,3,5,8,13,21 -codec:v mpeg4 -codec:a pcm_s16le -map 0 \
1755 -f segment -segment_list out.csv -segment_times 1,2,3,5,8,13,21 -segment_time_delta 0.05 out%03d.nut
1757 In order to force key frames on the input file, transcoding is
1761 Segment the input file by splitting the input file according to the
1762 frame numbers sequence specified with the @option{segment_frames} option:
1764 ffmpeg -i in.mkv -codec copy -map 0 -f segment -segment_list out.csv -segment_frames 100,200,300,500,800 out%03d.nut
1768 Convert the @file{in.mkv} to TS segments using the @code{libx264}
1769 and @code{aac} encoders:
1771 ffmpeg -i in.mkv -map 0 -codec:v libx264 -codec:a aac -f ssegment -segment_list out.list out%03d.ts
1775 Segment the input file, and create an M3U8 live playlist (can be used
1776 as live HLS source):
1778 ffmpeg -re -i in.mkv -codec copy -map 0 -f segment -segment_list playlist.m3u8 \
1779 -segment_list_flags +live -segment_time 10 out%03d.mkv
1783 @section smoothstreaming
1785 Smooth Streaming muxer generates a set of files (Manifest, chunks) suitable for serving with conventional web server.
1789 Specify the number of fragments kept in the manifest. Default 0 (keep all).
1791 @item extra_window_size
1792 Specify the number of fragments kept outside of the manifest before removing from disk. Default 5.
1794 @item lookahead_count
1795 Specify the number of lookahead fragments. Default 2.
1797 @item min_frag_duration
1798 Specify the minimum fragment duration (in microseconds). Default 5000000.
1800 @item remove_at_exit
1801 Specify whether to remove all fragments when finished. Default 0 (do not remove).
1808 The fifo pseudo-muxer allows the separation of encoding and muxing by using
1809 first-in-first-out queue and running the actual muxer in a separate thread. This
1810 is especially useful in combination with the @ref{tee} muxer and can be used to
1811 send data to several destinations with different reliability/writing speed/latency.
1813 API users should be aware that callback functions (interrupt_callback,
1814 io_open and io_close) used within its AVFormatContext must be thread-safe.
1816 The behavior of the fifo muxer if the queue fills up or if the output fails is
1822 output can be transparently restarted with configurable delay between retries
1823 based on real time or time of the processed stream.
1826 encoding can be blocked during temporary failure, or continue transparently
1827 dropping packets in case fifo queue fills up.
1834 Specify the format name. Useful if it cannot be guessed from the
1838 Specify size of the queue (number of packets). Default value is 60.
1841 Specify format options for the underlying muxer. Muxer options can be specified
1842 as a list of @var{key}=@var{value} pairs separated by ':'.
1844 @item drop_pkts_on_overflow @var{bool}
1845 If set to 1 (true), in case the fifo queue fills up, packets will be dropped
1846 rather than blocking the encoder. This makes it possible to continue streaming without
1847 delaying the input, at the cost of omitting part of the stream. By default
1848 this option is set to 0 (false), so in such cases the encoder will be blocked
1849 until the muxer processes some of the packets and none of them is lost.
1851 @item attempt_recovery @var{bool}
1852 If failure occurs, attempt to recover the output. This is especially useful
1853 when used with network output, since it makes it possible to restart streaming transparently.
1854 By default this option is set to 0 (false).
1856 @item max_recovery_attempts
1857 Sets maximum number of successive unsuccessful recovery attempts after which
1858 the output fails permanently. By default this option is set to 0 (unlimited).
1860 @item recovery_wait_time @var{duration}
1861 Waiting time before the next recovery attempt after previous unsuccessful
1862 recovery attempt. Default value is 5 seconds.
1864 @item recovery_wait_streamtime @var{bool}
1865 If set to 0 (false), the real time is used when waiting for the recovery
1866 attempt (i.e. the recovery will be attempted after at least
1867 recovery_wait_time seconds).
1868 If set to 1 (true), the time of the processed stream is taken into account
1869 instead (i.e. the recovery will be attempted after at least @var{recovery_wait_time}
1870 seconds of the stream is omitted).
1871 By default, this option is set to 0 (false).
1873 @item recover_any_error @var{bool}
1874 If set to 1 (true), recovery will be attempted regardless of type of the error
1875 causing the failure. By default this option is set to 0 (false) and in case of
1876 certain (usually permanent) errors the recovery is not attempted even when
1877 @var{attempt_recovery} is set to 1.
1879 @item restart_with_keyframe @var{bool}
1880 Specify whether to wait for the keyframe after recovering from
1881 queue overflow or failure. This option is set to 0 (false) by default.
1885 @subsection Examples
1890 Stream something to rtmp server, continue processing the stream at real-time
1891 rate even in case of temporary failure (network outage) and attempt to recover
1892 streaming every second indefinitely.
1894 ffmpeg -re -i ... -c:v libx264 -c:a aac -f fifo -fifo_format flv -map 0:v -map 0:a
1895 -drop_pkts_on_overflow 1 -attempt_recovery 1 -recovery_wait_time 1 rtmp://example.com/live/stream_name
1903 The tee muxer can be used to write the same data to several files or any
1904 other kind of muxer. It can be used, for example, to both stream a video to
1905 the network and save it to disk at the same time.
1907 It is different from specifying several outputs to the @command{ffmpeg}
1908 command-line tool because the audio and video data will be encoded only once
1909 with the tee muxer; encoding can be a very expensive process. It is not
1910 useful when using the libavformat API directly because it is then possible
1911 to feed the same packets to several muxers directly.
1915 @item use_fifo @var{bool}
1916 If set to 1, slave outputs will be processed in separate thread using @ref{fifo}
1917 muxer. This allows to compensate for different speed/latency/reliability of
1918 outputs and setup transparent recovery. By default this feature is turned off.
1921 Options to pass to fifo pseudo-muxer instances. See @ref{fifo}.
1925 The slave outputs are specified in the file name given to the muxer,
1926 separated by '|'. If any of the slave name contains the '|' separator,
1927 leading or trailing spaces or any special character, it must be
1928 escaped (see @ref{quoting_and_escaping,,the "Quoting and escaping"
1929 section in the ffmpeg-utils(1) manual,ffmpeg-utils}).
1931 Muxer options can be specified for each slave by prepending them as a list of
1932 @var{key}=@var{value} pairs separated by ':', between square brackets. If
1933 the options values contain a special character or the ':' separator, they
1934 must be escaped; note that this is a second level escaping.
1936 The following special options are also recognized:
1939 Specify the format name. Useful if it cannot be guessed from the
1942 @item bsfs[/@var{spec}]
1943 Specify a list of bitstream filters to apply to the specified
1946 @item use_fifo @var{bool}
1947 This allows to override tee muxer use_fifo option for individual slave muxer.
1950 This allows to override tee muxer fifo_options for individual slave muxer.
1953 It is possible to specify to which streams a given bitstream filter
1954 applies, by appending a stream specifier to the option separated by
1955 @code{/}. @var{spec} must be a stream specifier (see @ref{Format
1956 stream specifiers}). If the stream specifier is not specified, the
1957 bitstream filters will be applied to all streams in the output.
1959 Several bitstream filters can be specified, separated by ",".
1962 Select the streams that should be mapped to the slave output,
1963 specified by a stream specifier. If not specified, this defaults to
1964 all the input streams. You may use multiple stream specifiers
1965 separated by commas (@code{,}) e.g.: @code{a:0,v}
1968 Specify behaviour on output failure. This can be set to either @code{abort} (which is
1969 default) or @code{ignore}. @code{abort} will cause whole process to fail in case of failure
1970 on this slave output. @code{ignore} will ignore failure on this output, so other outputs
1971 will continue without being affected.
1974 @subsection Examples
1978 Encode something and both archive it in a WebM file and stream it
1979 as MPEG-TS over UDP (the streams need to be explicitly mapped):
1981 ffmpeg -i ... -c:v libx264 -c:a mp2 -f tee -map 0:v -map 0:a
1982 "archive-20121107.mkv|[f=mpegts]udp://10.0.1.255:1234/"
1986 As above, but continue streaming even if output to local file fails
1987 (for example local drive fills up):
1989 ffmpeg -i ... -c:v libx264 -c:a mp2 -f tee -map 0:v -map 0:a
1990 "[onfail=ignore]archive-20121107.mkv|[f=mpegts]udp://10.0.1.255:1234/"
1994 Use @command{ffmpeg} to encode the input, and send the output
1995 to three different destinations. The @code{dump_extra} bitstream
1996 filter is used to add extradata information to all the output video
1997 keyframes packets, as requested by the MPEG-TS format. The select
1998 option is applied to @file{out.aac} in order to make it contain only
2001 ffmpeg -i ... -map 0 -flags +global_header -c:v libx264 -c:a aac
2002 -f tee "[bsfs/v=dump_extra]out.ts|[movflags=+faststart]out.mp4|[select=a]out.aac"
2006 As below, but select only stream @code{a:1} for the audio output. Note
2007 that a second level escaping must be performed, as ":" is a special
2008 character used to separate options.
2010 ffmpeg -i ... -map 0 -flags +global_header -c:v libx264 -c:a aac
2011 -f tee "[bsfs/v=dump_extra]out.ts|[movflags=+faststart]out.mp4|[select=\'a:1\']out.aac"
2015 Note: some codecs may need different options depending on the output format;
2016 the auto-detection of this can not work with the tee muxer. The main example
2017 is the @option{global_header} flag.
2019 @section webm_dash_manifest
2021 WebM DASH Manifest muxer.
2023 This muxer implements the WebM DASH Manifest specification to generate the DASH
2024 manifest XML. It also supports manifest generation for DASH live streams.
2026 For more information see:
2030 WebM DASH Specification: @url{https://sites.google.com/a/webmproject.org/wiki/adaptive-streaming/webm-dash-specification}
2032 ISO DASH Specification: @url{http://standards.iso.org/ittf/PubliclyAvailableStandards/c065274_ISO_IEC_23009-1_2014.zip}
2037 This muxer supports the following options:
2040 @item adaptation_sets
2041 This option has the following syntax: "id=x,streams=a,b,c id=y,streams=d,e" where x and y are the
2042 unique identifiers of the adaptation sets and a,b,c,d and e are the indices of the corresponding
2043 audio and video streams. Any number of adaptation sets can be added using this option.
2046 Set this to 1 to create a live stream DASH Manifest. Default: 0.
2048 @item chunk_start_index
2049 Start index of the first chunk. This will go in the @samp{startNumber} attribute
2050 of the @samp{SegmentTemplate} element in the manifest. Default: 0.
2052 @item chunk_duration_ms
2053 Duration of each chunk in milliseconds. This will go in the @samp{duration}
2054 attribute of the @samp{SegmentTemplate} element in the manifest. Default: 1000.
2056 @item utc_timing_url
2057 URL of the page that will return the UTC timestamp in ISO format. This will go
2058 in the @samp{value} attribute of the @samp{UTCTiming} element in the manifest.
2061 @item time_shift_buffer_depth
2062 Smallest time (in seconds) shifting buffer for which any Representation is
2063 guaranteed to be available. This will go in the @samp{timeShiftBufferDepth}
2064 attribute of the @samp{MPD} element. Default: 60.
2066 @item minimum_update_period
2067 Minimum update period (in seconds) of the manifest. This will go in the
2068 @samp{minimumUpdatePeriod} attribute of the @samp{MPD} element. Default: 0.
2074 ffmpeg -f webm_dash_manifest -i video1.webm \
2075 -f webm_dash_manifest -i video2.webm \
2076 -f webm_dash_manifest -i audio1.webm \
2077 -f webm_dash_manifest -i audio2.webm \
2078 -map 0 -map 1 -map 2 -map 3 \
2080 -f webm_dash_manifest \
2081 -adaptation_sets "id=0,streams=0,1 id=1,streams=2,3" \
2087 WebM Live Chunk Muxer.
2089 This muxer writes out WebM headers and chunks as separate files which can be
2090 consumed by clients that support WebM Live streams via DASH.
2094 This muxer supports the following options:
2097 @item chunk_start_index
2098 Index of the first chunk (defaults to 0).
2101 Filename of the header where the initialization data will be written.
2103 @item audio_chunk_duration
2104 Duration of each audio chunk in milliseconds (defaults to 5000).
2109 ffmpeg -f v4l2 -i /dev/video0 \
2113 -s 640x360 -keyint_min 30 -g 30 \
2115 -header webm_live_video_360.hdr \
2116 -chunk_start_index 1 \
2117 webm_live_video_360_%d.chk \
2122 -header webm_live_audio_128.hdr \
2123 -chunk_start_index 1 \
2124 -audio_chunk_duration 1000 \
2125 webm_live_audio_128_%d.chk