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,
100 which generates a fingerprint for the provided audio data. See @url{https://acoustid.org/chromaprint}
102 It takes a single signed native-endian 16-bit raw audio stream of at most 2 channels.
107 @item silence_threshold
108 Threshold for detecting silence, ranges from -1 to 32767. -1 disables silence detection and
109 is required for use with the AcoustID service. Default is -1.
112 Version of algorithm to fingerprint with. Range is 0 to 4. Version 2 requires that silence
113 detection be enabled. Default is 1.
116 Format to output the fingerprint as. Accepts the following options:
119 Binary raw fingerprint
122 Binary compressed fingerprint
125 Base64 compressed fingerprint @emph{(default)}
134 CRC (Cyclic Redundancy Check) testing format.
136 This muxer computes and prints the Adler-32 CRC of all the input audio
137 and video frames. By default audio frames are converted to signed
138 16-bit raw audio and video frames to raw video before computing the
141 The output of the muxer consists of a single line of the form:
142 CRC=0x@var{CRC}, where @var{CRC} is a hexadecimal number 0-padded to
143 8 digits containing the CRC for all the decoded input frames.
145 See also the @ref{framecrc} muxer.
149 For example to compute the CRC of the input, and store it in the file
152 ffmpeg -i INPUT -f crc out.crc
155 You can print the CRC to stdout with the command:
157 ffmpeg -i INPUT -f crc -
160 You can select the output format of each frame with @command{ffmpeg} by
161 specifying the audio and video codec and format. For example to
162 compute the CRC of the input audio converted to PCM unsigned 8-bit
163 and the input video converted to MPEG-2 video, use the command:
165 ffmpeg -i INPUT -c:a pcm_u8 -c:v mpeg2video -f crc -
170 Adobe Flash Video Format muxer.
172 This muxer accepts the following options:
176 @item flvflags @var{flags}
181 @item aac_seq_header_detect
182 Place AAC sequence header based on audio stream data.
184 @item no_sequence_end
185 Disable sequence end tag.
188 Disable metadata tag.
190 @item no_duration_filesize
191 Disable duration and filesize in metadata when they are equal to zero
192 at the end of stream. (Be used to non-seekable living stream).
194 @item add_keyframe_index
195 Used to facilitate seeking; particularly for HTTP pseudo streaming.
202 Dynamic Adaptive Streaming over HTTP (DASH) muxer that creates segments
203 and manifest files according to the MPEG-DASH standard ISO/IEC 23009-1:2014.
205 For more information see:
209 ISO DASH Specification: @url{http://standards.iso.org/ittf/PubliclyAvailableStandards/c065274_ISO_IEC_23009-1_2014.zip}
211 WebM DASH Specification: @url{https://sites.google.com/a/webmproject.org/wiki/adaptive-streaming/webm-dash-specification}
214 It creates a MPD manifest file and segment files for each stream.
216 The segment filename might contain pre-defined identifiers used with SegmentTemplate
217 as defined in section 5.3.9.4.4 of the standard. Available identifiers are "$RepresentationID$",
218 "$Number$", "$Bandwidth$" and "$Time$".
219 In addition to the standard identifiers, an ffmpeg-specific "$ext$" identifier is also supported.
220 When specified ffmpeg will replace $ext$ in the file name with muxing format's extensions such as mp4, webm etc.,
223 ffmpeg -re -i <input> -map 0 -map 0 -c:a libfdk_aac -c:v libx264
224 -b:v:0 800k -b:v:1 300k -s:v:1 320x170 -profile:v:1 baseline
225 -profile:v:0 main -bf 1 -keyint_min 120 -g 120 -sc_threshold 0
226 -b_strategy 0 -ar:a:1 22050 -use_timeline 1 -use_template 1
227 -window_size 5 -adaptation_sets "id=0,streams=v id=1,streams=a"
228 -f dash /path/to/out.mpd
232 @item -min_seg_duration @var{microseconds}
233 This is a deprecated option to set the segment length in microseconds, use @var{seg_duration} instead.
234 @item -seg_duration @var{duration}
235 Set the segment length in seconds (fractional value can be set). The value is
236 treated as average segment duration when @var{use_template} is enabled and
237 @var{use_timeline} is disabled and as minimum segment duration for all the other
239 @item -window_size @var{size}
240 Set the maximum number of segments kept in the manifest.
241 @item -extra_window_size @var{size}
242 Set the maximum number of segments kept outside of the manifest before removing from disk.
243 @item -remove_at_exit @var{remove}
244 Enable (1) or disable (0) removal of all segments when finished.
245 @item -use_template @var{template}
246 Enable (1) or disable (0) use of SegmentTemplate instead of SegmentList.
247 @item -use_timeline @var{timeline}
248 Enable (1) or disable (0) use of SegmentTimeline in SegmentTemplate.
249 @item -single_file @var{single_file}
250 Enable (1) or disable (0) storing all segments in one file, accessed using byte ranges.
251 @item -single_file_name @var{file_name}
252 DASH-templated name to be used for baseURL. Implies @var{single_file} set to "1". In the template, "$ext$" is replaced with the file name extension specific for the segment format.
253 @item -init_seg_name @var{init_name}
254 DASH-templated name to used for the initialization segment. Default is "init-stream$RepresentationID$.$ext$". "$ext$" is replaced with the file name extension specific for the segment format.
255 @item -media_seg_name @var{segment_name}
256 DASH-templated name to used for the media segments. Default is "chunk-stream$RepresentationID$-$Number%05d$.$ext$". "$ext$" is replaced with the file name extension specific for the segment format.
257 @item -utc_timing_url @var{utc_url}
258 URL of the page that will return the UTC timestamp in ISO format. Example: "https://time.akamai.com/?iso"
259 @item method @var{method}
260 Use the given HTTP method to create output files. Generally set to PUT or POST.
261 @item -http_user_agent @var{user_agent}
262 Override User-Agent field in HTTP header. Applicable only for HTTP output.
263 @item -http_persistent @var{http_persistent}
264 Use persistent HTTP connections. Applicable only for HTTP output.
265 @item -hls_playlist @var{hls_playlist}
266 Generate HLS playlist files as well. The master playlist is generated with the filename master.m3u8.
267 One media playlist file is generated for each stream with filenames media_0.m3u8, media_1.m3u8, etc.
268 @item -streaming @var{streaming}
269 Enable (1) or disable (0) chunk streaming mode of output. In chunk streaming
270 mode, each frame will be a moof fragment which forms a chunk.
271 @item -adaptation_sets @var{adaptation_sets}
272 Assign streams to AdaptationSets. Syntax is "id=x,streams=a,b,c id=y,streams=d,e" with x and y being the IDs
273 of the adaptation sets and a,b,c,d and e are the indices of the mapped streams.
275 To map all video (or audio) streams to an AdaptationSet, "v" (or "a") can be used as stream identifier instead of IDs.
277 When no assignment is defined, this defaults to an AdaptationSet for each stream.
278 @item -timeout @var{timeout}
279 Set timeout for socket I/O operations. Applicable only for HTTP output.
280 @item -index_correction @var{index_correction}
281 Enable (1) or Disable (0) segment index correction logic. Applicable only when
282 @var{use_template} is enabled and @var{use_timeline} is disabled.
284 When enabled, the logic monitors the flow of segment indexes. If a streams's
285 segment index value is not at the expected real time position, then the logic
286 corrects that index value.
288 Typically this logic is needed in live streaming use cases. The network bandwidth
289 fluctuations are common during long run streaming. Each fluctuation can cause
290 the segment indexes fall behind the expected real time position.
291 @item -format_options @var{options_list}
292 Set container format (mp4/webm) options using a @code{:} separated list of
293 key=value parameters. Values containing @code{:} special characters must be
296 @item -global_sidx @var{global_sidx}
297 Write global SIDX atom. Applicable only for single file, mp4 output, non-streaming mode.
299 @item -dash_segment_type @var{dash_segment_type}
302 If this flag is set, the dash segment files format will be selected based on the stream codec. This is the default mode.
305 If this flag is set, the dash segment files will be in in ISOBMFF format.
308 If this flag is set, the dash segment files will be in in WebM format.
310 @item -ignore_io_errors @var{ignore_io_errors}
311 Ignore IO errors during open and write. Useful for long-duration runs with network output.
313 @item -lhls @var{lhls}
314 Enable Low-latency HLS(LHLS). Adds #EXT-X-PREFETCH tag with current segment's URI.
315 Apple doesn't have an official spec for LHLS. Meanwhile hls.js player folks are
316 trying to standardize a open LHLS spec. The draft spec is available in https://github.com/video-dev/hlsjs-rfcs/blob/lhls-spec/proposals/0001-lhls.md
317 This option will also try to comply with the above open spec, till Apple's spec officially supports it.
318 Applicable only when @var{streaming} and @var{hls_playlist} options are enabled.
319 This is an experimental feature.
321 @item -master_m3u8_publish_rate @var{master_m3u8_publish_rate}
322 Publish master playlist repeatedly every after specified number of segment intervals.
329 Per-packet CRC (Cyclic Redundancy Check) testing format.
331 This muxer computes and prints the Adler-32 CRC for each audio
332 and video packet. By default audio frames are converted to signed
333 16-bit raw audio and video frames to raw video before computing the
336 The output of the muxer consists of a line for each audio and video
339 @var{stream_index}, @var{packet_dts}, @var{packet_pts}, @var{packet_duration}, @var{packet_size}, 0x@var{CRC}
342 @var{CRC} is a hexadecimal number 0-padded to 8 digits containing the
347 For example to compute the CRC of the audio and video frames in
348 @file{INPUT}, converted to raw audio and video packets, and store it
349 in the file @file{out.crc}:
351 ffmpeg -i INPUT -f framecrc out.crc
354 To print the information to stdout, use the command:
356 ffmpeg -i INPUT -f framecrc -
359 With @command{ffmpeg}, you can select the output format to which the
360 audio and video frames are encoded before computing the CRC for each
361 packet by specifying the audio and video codec. For example, to
362 compute the CRC of each decoded input audio frame converted to PCM
363 unsigned 8-bit and of each decoded input video frame converted to
364 MPEG-2 video, use the command:
366 ffmpeg -i INPUT -c:a pcm_u8 -c:v mpeg2video -f framecrc -
369 See also the @ref{crc} muxer.
374 Per-packet hash testing format.
376 This muxer computes and prints a cryptographic hash for each audio
377 and video packet. This can be used for packet-by-packet equality
378 checks without having to individually do a binary comparison on each.
380 By default audio frames are converted to signed 16-bit raw audio and
381 video frames to raw video before computing the hash, but the output
382 of explicit conversions to other codecs can also be used. It uses the
383 SHA-256 cryptographic hash function by default, but supports several
386 The output of the muxer consists of a line for each audio and video
389 @var{stream_index}, @var{packet_dts}, @var{packet_pts}, @var{packet_duration}, @var{packet_size}, @var{hash}
392 @var{hash} is a hexadecimal number representing the computed hash
396 @item hash @var{algorithm}
397 Use the cryptographic hash function specified by the string @var{algorithm}.
398 Supported values include @code{MD5}, @code{murmur3}, @code{RIPEMD128},
399 @code{RIPEMD160}, @code{RIPEMD256}, @code{RIPEMD320}, @code{SHA160},
400 @code{SHA224}, @code{SHA256} (default), @code{SHA512/224}, @code{SHA512/256},
401 @code{SHA384}, @code{SHA512}, @code{CRC32} and @code{adler32}.
407 To compute the SHA-256 hash of the audio and video frames in @file{INPUT},
408 converted to raw audio and video packets, and store it in the file
411 ffmpeg -i INPUT -f framehash out.sha256
414 To print the information to stdout, using the MD5 hash function, use
417 ffmpeg -i INPUT -f framehash -hash md5 -
420 See also the @ref{hash} muxer.
425 Per-packet MD5 testing format.
427 This is a variant of the @ref{framehash} muxer. Unlike that muxer,
428 it defaults to using the MD5 hash function.
432 To compute the MD5 hash of the audio and video frames in @file{INPUT},
433 converted to raw audio and video packets, and store it in the file
436 ffmpeg -i INPUT -f framemd5 out.md5
439 To print the information to stdout, use the command:
441 ffmpeg -i INPUT -f framemd5 -
444 See also the @ref{framehash} and @ref{md5} muxers.
451 It accepts the following options:
455 Set the number of times to loop the output. Use @code{-1} for no loop, @code{0}
456 for looping indefinitely (default).
459 Force the delay (expressed in centiseconds) after the last frame. Each frame
460 ends with a delay until the next frame. The default is @code{-1}, which is a
461 special value to tell the muxer to re-use the previous delay. In case of a
462 loop, you might want to customize this value to mark a pause for instance.
465 For example, to encode a gif looping 10 times, with a 5 seconds delay between
468 ffmpeg -i INPUT -loop 10 -final_delay 500 out.gif
471 Note 1: if you wish to extract the frames into separate GIF files, you need to
472 force the @ref{image2} muxer:
474 ffmpeg -i INPUT -c:v gif -f image2 "out%d.gif"
477 Note 2: the GIF format has a very large time base: the delay between two frames
478 can therefore not be smaller than one centi second.
485 This muxer computes and prints a cryptographic hash of all the input
486 audio and video frames. This can be used for equality checks without
487 having to do a complete binary comparison.
489 By default audio frames are converted to signed 16-bit raw audio and
490 video frames to raw video before computing the hash, but the output
491 of explicit conversions to other codecs can also be used. Timestamps
492 are ignored. It uses the SHA-256 cryptographic hash function by default,
493 but supports several other algorithms.
495 The output of the muxer consists of a single line of the form:
496 @var{algo}=@var{hash}, where @var{algo} is a short string representing
497 the hash function used, and @var{hash} is a hexadecimal number
498 representing the computed hash.
501 @item hash @var{algorithm}
502 Use the cryptographic hash function specified by the string @var{algorithm}.
503 Supported values include @code{MD5}, @code{murmur3}, @code{RIPEMD128},
504 @code{RIPEMD160}, @code{RIPEMD256}, @code{RIPEMD320}, @code{SHA160},
505 @code{SHA224}, @code{SHA256} (default), @code{SHA512/224}, @code{SHA512/256},
506 @code{SHA384}, @code{SHA512}, @code{CRC32} and @code{adler32}.
512 To compute the SHA-256 hash of the input converted to raw audio and
513 video, and store it in the file @file{out.sha256}:
515 ffmpeg -i INPUT -f hash out.sha256
518 To print an MD5 hash to stdout use the command:
520 ffmpeg -i INPUT -f hash -hash md5 -
523 See also the @ref{framehash} muxer.
528 Apple HTTP Live Streaming muxer that segments MPEG-TS according to
529 the HTTP Live Streaming (HLS) specification.
531 It creates a playlist file, and one or more segment files. The output filename
532 specifies the playlist filename.
534 By default, the muxer creates a file for each segment produced. These files
535 have the same name as the playlist, followed by a sequential number and a
538 Make sure to require a closed GOP when encoding and to set the GOP
539 size to fit your segment time constraint.
541 For example, to convert an input file with @command{ffmpeg}:
543 ffmpeg -i in.mkv -c:v h264 -flags +cgop -g 30 -hls_time 1 out.m3u8
545 This example will produce the playlist, @file{out.m3u8}, and segment files:
546 @file{out0.ts}, @file{out1.ts}, @file{out2.ts}, etc.
548 See also the @ref{segment} muxer, which provides a more generic and
549 flexible implementation of a segmenter, and can be used to perform HLS
554 This muxer supports the following options:
557 @item hls_init_time @var{seconds}
558 Set the initial target segment length in seconds. Default value is @var{0}.
559 Segment will be cut on the next key frame after this time has passed on the first m3u8 list.
560 After the initial playlist is filled @command{ffmpeg} will cut segments
561 at duration equal to @code{hls_time}
563 @item hls_time @var{seconds}
564 Set the target segment length in seconds. Default value is 2.
565 Segment will be cut on the next key frame after this time has passed.
567 @item hls_list_size @var{size}
568 Set the maximum number of playlist entries. If set to 0 the list file
569 will contain all the segments. Default value is 5.
571 @item hls_delete_threshold @var{size}
572 Set the number of unreferenced segments to keep on disk before @code{hls_flags delete_segments}
573 deletes them. Increase this to allow continue clients to download segments which
574 were recently referenced in the playlist. Default value is 1, meaning segments older than
575 @code{hls_list_size+1} will be deleted.
577 @item hls_ts_options @var{options_list}
578 Set output format options using a :-separated list of key=value
579 parameters. Values containing @code{:} special characters must be
582 @item hls_wrap @var{wrap}
583 This is a deprecated option, you can use @code{hls_list_size}
584 and @code{hls_flags delete_segments} instead it
586 This option is useful to avoid to fill the disk with many segment
587 files, and limits the maximum number of segment files written to disk
591 @item hls_start_number_source
592 Start the playlist sequence number (@code{#EXT-X-MEDIA-SEQUENCE}) according to the specified source.
593 Unless @code{hls_flags single_file} is set, it also specifies source of starting sequence numbers of
594 segment and subtitle filenames. In any case, if @code{hls_flags append_list}
595 is set and read playlist sequence number is greater than the specified start sequence number,
596 then that value will be used as start value.
598 It accepts the following values:
602 @item generic (default)
603 Set the starting sequence numbers according to @var{start_number} option value.
606 The start number will be the seconds since epoch (1970-01-01 00:00:00)
609 The start number will be based on the current date/time as YYYYmmddHHMMSS. e.g. 20161231235759.
613 @item start_number @var{number}
614 Start the playlist sequence number (@code{#EXT-X-MEDIA-SEQUENCE}) from the specified @var{number}
615 when @var{hls_start_number_source} value is @var{generic}. (This is the default case.)
616 Unless @code{hls_flags single_file} is set, it also specifies starting sequence numbers of segment and subtitle filenames.
619 @item hls_allow_cache @var{allowcache}
620 Explicitly set whether the client MAY (1) or MUST NOT (0) cache media segments.
622 @item hls_base_url @var{baseurl}
623 Append @var{baseurl} to every entry in the playlist.
624 Useful to generate playlists with absolute paths.
626 Note that the playlist sequence number must be unique for each segment
627 and it is not to be confused with the segment filename sequence number
628 which can be cyclic, for example if the @option{wrap} option is
631 @item hls_segment_filename @var{filename}
632 Set the segment filename. Unless @code{hls_flags single_file} is set,
633 @var{filename} is used as a string format with the segment number:
635 ffmpeg -i in.nut -hls_segment_filename 'file%03d.ts' out.m3u8
637 This example will produce the playlist, @file{out.m3u8}, and segment files:
638 @file{file000.ts}, @file{file001.ts}, @file{file002.ts}, etc.
640 @var{filename} may contain full path or relative path specification,
641 but only the file name part without any path info will be contained in the m3u8 segment list.
642 Should a relative path be specified, the path of the created segment
643 files will be relative to the current working directory.
644 When strftime_mkdir is set, the whole expanded value of @var{filename} will be written into the m3u8 segment list.
646 When @code{var_stream_map} is set with two or more variant streams, the
647 @var{filename} pattern must contain the string "%v", this string specifies
648 the position of variant stream index in the generated segment file names.
650 ffmpeg -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k -b:a:1 32k \
651 -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" \
652 -hls_segment_filename 'file_%v_%03d.ts' out_%v.m3u8
654 This example will produce the playlists segment file sets:
655 @file{file_0_000.ts}, @file{file_0_001.ts}, @file{file_0_002.ts}, etc. and
656 @file{file_1_000.ts}, @file{file_1_001.ts}, @file{file_1_002.ts}, etc.
658 The string "%v" may be present in the filename or in the last directory name
659 containing the file. If the string is present in the directory name, then
660 sub-directories are created after expanding the directory name pattern. This
661 enables creation of segments corresponding to different variant streams in
664 ffmpeg -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k -b:a:1 32k \
665 -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" \
666 -hls_segment_filename 'vs%v/file_%03d.ts' vs%v/out.m3u8
668 This example will produce the playlists segment file sets:
669 @file{vs0/file_000.ts}, @file{vs0/file_001.ts}, @file{vs0/file_002.ts}, etc. and
670 @file{vs1/file_000.ts}, @file{vs1/file_001.ts}, @file{vs1/file_002.ts}, etc.
673 Same as strftime option, will be deprecated.
676 Use strftime() on @var{filename} to expand the segment filename with localtime.
677 The segment number is also available in this mode, but to use it, you need to specify second_level_segment_index
678 hls_flag and %%d will be the specifier.
680 ffmpeg -i in.nut -strftime 1 -hls_segment_filename 'file-%Y%m%d-%s.ts' out.m3u8
682 This example will produce the playlist, @file{out.m3u8}, and segment files:
683 @file{file-20160215-1455569023.ts}, @file{file-20160215-1455569024.ts}, etc.
684 Note: On some systems/environments, the @code{%s} specifier is not available. See
685 @code{strftime()} documentation.
687 ffmpeg -i in.nut -strftime 1 -hls_flags second_level_segment_index -hls_segment_filename 'file-%Y%m%d-%%04d.ts' out.m3u8
689 This example will produce the playlist, @file{out.m3u8}, and segment files:
690 @file{file-20160215-0001.ts}, @file{file-20160215-0002.ts}, etc.
692 @item use_localtime_mkdir
693 Same as strftime_mkdir option, will be deprecated .
696 Used together with -strftime_mkdir, it will create all subdirectories which
697 is expanded in @var{filename}.
699 ffmpeg -i in.nut -strftime 1 -strftime_mkdir 1 -hls_segment_filename '%Y%m%d/file-%Y%m%d-%s.ts' out.m3u8
701 This example will create a directory 201560215 (if it does not exist), and then
702 produce the playlist, @file{out.m3u8}, and segment files:
703 @file{20160215/file-20160215-1455569023.ts}, @file{20160215/file-20160215-1455569024.ts}, etc.
706 ffmpeg -i in.nut -strftime 1 -strftime_mkdir 1 -hls_segment_filename '%Y/%m/%d/file-%Y%m%d-%s.ts' out.m3u8
708 This example will create a directory hierarchy 2016/02/15 (if any of them do not exist), and then
709 produce the playlist, @file{out.m3u8}, and segment files:
710 @file{2016/02/15/file-20160215-1455569023.ts}, @file{2016/02/15/file-20160215-1455569024.ts}, etc.
713 @item hls_key_info_file @var{key_info_file}
714 Use the information in @var{key_info_file} for segment encryption. The first
715 line of @var{key_info_file} specifies the key URI written to the playlist. The
716 key URL is used to access the encryption key during playback. The second line
717 specifies the path to the key file used to obtain the key during the encryption
718 process. The key file is read as a single packed array of 16 octets in binary
719 format. The optional third line specifies the initialization vector (IV) as a
720 hexadecimal string to be used instead of the segment sequence number (default)
721 for encryption. Changes to @var{key_info_file} will result in segment
722 encryption with the new key/IV and an entry in the playlist for the new key
723 URI/IV if @code{hls_flags periodic_rekey} is enabled.
725 Key info file format:
734 http://server/file.key
739 Example key file paths:
747 0123456789ABCDEF0123456789ABCDEF
750 Key info file example:
752 http://server/file.key
754 0123456789ABCDEF0123456789ABCDEF
757 Example shell script:
761 openssl rand 16 > file.key
762 echo $BASE_URL/file.key > file.keyinfo
763 echo file.key >> file.keyinfo
764 echo $(openssl rand -hex 16) >> file.keyinfo
765 ffmpeg -f lavfi -re -i testsrc -c:v h264 -hls_flags delete_segments \
766 -hls_key_info_file file.keyinfo out.m3u8
769 @item -hls_enc @var{enc}
770 Enable (1) or disable (0) the AES128 encryption.
771 When enabled every segment generated is encrypted and the encryption key
772 is saved as @var{playlist name}.key.
774 @item -hls_enc_key @var{key}
775 Hex-coded 16byte key to encrypt the segments, by default it
776 is randomly generated.
778 @item -hls_enc_key_url @var{keyurl}
779 If set, @var{keyurl} is prepended instead of @var{baseurl} to the key filename
782 @item -hls_enc_iv @var{iv}
783 Hex-coded 16byte initialization vector for every segment instead
784 of the autogenerated ones.
786 @item hls_segment_type @var{flags}
791 Output segment files in MPEG-2 Transport Stream format. This is
792 compatible with all HLS versions.
795 Output segment files in fragmented MP4 format, similar to MPEG-DASH.
796 fmp4 files may be used in HLS version 7 and above.
800 @item hls_fmp4_init_filename @var{filename}
801 Set filename to the fragment files header file, default filename is @file{init.mp4}.
803 When @code{var_stream_map} is set with two or more variant streams, the
804 @var{filename} pattern must contain the string "%v", this string specifies
805 the position of variant stream index in the generated init file names.
806 The string "%v" may be present in the filename or in the last directory name
807 containing the file. If the string is present in the directory name, then
808 sub-directories are created after expanding the directory name pattern. This
809 enables creation of init files corresponding to different variant streams in
812 @item hls_flags @var{flags}
817 If this flag is set, the muxer will store all segments in a single MPEG-TS
818 file, and will use byte ranges in the playlist. HLS playlists generated with
819 this way will have the version number 4.
822 ffmpeg -i in.nut -hls_flags single_file out.m3u8
824 Will produce the playlist, @file{out.m3u8}, and a single segment file,
827 @item delete_segments
828 Segment files removed from the playlist are deleted after a period of time
829 equal to the duration of the segment plus the duration of the playlist.
832 Append new segments into the end of old segment list,
833 and remove the @code{#EXT-X-ENDLIST} from the old segment list.
835 @item round_durations
836 Round the duration info in the playlist file segment info to integer
837 values, instead of using floating point.
840 Add the @code{#EXT-X-DISCONTINUITY} tag to the playlist, before the
841 first segment's information.
844 Do not append the @code{EXT-X-ENDLIST} tag at the end of the playlist.
847 The file specified by @code{hls_key_info_file} will be checked periodically and
848 detect updates to the encryption info. Be sure to replace this file atomically,
849 including the file containing the AES encryption key.
851 @item independent_segments
852 Add the @code{#EXT-X-INDEPENDENT-SEGMENTS} to playlists that has video segments
853 and when all the segments of that playlist are guaranteed to start with a Key frame.
856 Add the @code{#EXT-X-I-FRAMES-ONLY} to playlists that has video segments
857 and can play only I-frames in the @code{#EXT-X-BYTERANGE} mode.
860 Allow segments to start on frames other than keyframes. This improves
861 behavior on some players when the time between keyframes is inconsistent,
862 but may make things worse on others, and can cause some oddities during
863 seeking. This flag should be used with the @code{hls_time} option.
865 @item program_date_time
866 Generate @code{EXT-X-PROGRAM-DATE-TIME} tags.
868 @item second_level_segment_index
869 Makes it possible to use segment indexes as %%d in hls_segment_filename expression
870 besides date/time values when strftime is on.
871 To get fixed width numbers with trailing zeroes, %%0xd format is available where x is the required width.
873 @item second_level_segment_size
874 Makes it possible to use segment sizes (counted in bytes) as %%s in hls_segment_filename
875 expression besides date/time values when strftime is on.
876 To get fixed width numbers with trailing zeroes, %%0xs format is available where x is the required width.
878 @item second_level_segment_duration
879 Makes it possible to use segment duration (calculated in microseconds) as %%t in hls_segment_filename
880 expression besides date/time values when strftime is on.
881 To get fixed width numbers with trailing zeroes, %%0xt format is available where x is the required width.
884 ffmpeg -i sample.mpeg \
885 -f hls -hls_time 3 -hls_list_size 5 \
886 -hls_flags second_level_segment_index+second_level_segment_size+second_level_segment_duration \
887 -strftime 1 -strftime_mkdir 1 -hls_segment_filename "segment_%Y%m%d%H%M%S_%%04d_%%08s_%%013t.ts" stream.m3u8
889 This will produce segments like this:
890 @file{segment_20170102194334_0003_00122200_0000003000000.ts}, @file{segment_20170102194334_0004_00120072_0000003000000.ts} etc.
893 Write segment data to filename.tmp and rename to filename only once the segment is complete. A webserver
894 serving up segments can be configured to reject requests to *.tmp to prevent access to in-progress segments
895 before they have been added to the m3u8 playlist.
899 @item hls_playlist_type event
900 Emit @code{#EXT-X-PLAYLIST-TYPE:EVENT} in the m3u8 header. Forces
901 @option{hls_list_size} to 0; the playlist can only be appended to.
903 @item hls_playlist_type vod
904 Emit @code{#EXT-X-PLAYLIST-TYPE:VOD} in the m3u8 header. Forces
905 @option{hls_list_size} to 0; the playlist must not change.
908 Use the given HTTP method to create the hls files.
910 ffmpeg -re -i in.ts -f hls -method PUT http://example.com/live/out.m3u8
912 This example will upload all the mpegts segment files to the HTTP
913 server using the HTTP PUT method, and update the m3u8 files every
914 @code{refresh} times using the same method.
915 Note that the HTTP server must support the given method for uploading
918 @item http_user_agent
919 Override User-Agent field in HTTP header. Applicable only for HTTP output.
922 Map string which specifies how to group the audio, video and subtitle streams
923 into different variant streams. The variant stream groups are separated
925 Expected string format is like this "a:0,v:0 a:1,v:1 ....". Here a:, v:, s: are
926 the keys to specify audio, video and subtitle streams respectively.
927 Allowed values are 0 to 9 (limited just based on practical usage).
929 When there are two or more variant streams, the output filename pattern must
930 contain the string "%v", this string specifies the position of variant stream
931 index in the output media playlist filenames. The string "%v" may be present in
932 the filename or in the last directory name containing the file. If the string is
933 present in the directory name, then sub-directories are created after expanding
934 the directory name pattern. This enables creation of variant streams in
938 ffmpeg -re -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k -b:a:1 32k \
939 -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" \
940 http://example.com/live/out_%v.m3u8
942 This example creates two hls variant streams. The first variant stream will
943 contain video stream of bitrate 1000k and audio stream of bitrate 64k and the
944 second variant stream will contain video stream of bitrate 256k and audio
945 stream of bitrate 32k. Here, two media playlist with file names out_0.m3u8 and
946 out_1.m3u8 will be created.
948 ffmpeg -re -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k \
949 -map 0:v -map 0:a -map 0:v -f hls -var_stream_map "v:0 a:0 v:1" \
950 http://example.com/live/out_%v.m3u8
952 This example creates three hls variant streams. The first variant stream will
953 be a video only stream with video bitrate 1000k, the second variant stream will
954 be an audio only stream with bitrate 64k and the third variant stream will be a
955 video only stream with bitrate 256k. Here, three media playlist with file names
956 out_0.m3u8, out_1.m3u8 and out_2.m3u8 will be created.
958 ffmpeg -re -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k -b:a:1 32k \
959 -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" \
960 http://example.com/live/vs_%v/out.m3u8
962 This example creates the variant streams in subdirectories. Here, the first
963 media playlist is created at @file{http://example.com/live/vs_0/out.m3u8} and
964 the second one at @file{http://example.com/live/vs_1/out.m3u8}.
966 ffmpeg -re -i in.ts -b:a:0 32k -b:a:1 64k -b:v:0 1000k -b:v:1 3000k \
967 -map 0:a -map 0:a -map 0:v -map 0:v -f hls \
968 -var_stream_map "a:0,agroup:aud_low a:1,agroup:aud_high v:0,agroup:aud_low v:1,agroup:aud_high" \
969 -master_pl_name master.m3u8 \
970 http://example.com/live/out_%v.m3u8
972 This example creates two audio only and two video only variant streams. In
973 addition to the #EXT-X-STREAM-INF tag for each variant stream in the master
974 playlist, #EXT-X-MEDIA tag is also added for the two audio only variant streams
975 and they are mapped to the two video only variant streams with audio group names
976 'aud_low' and 'aud_high'.
978 By default, a single hls variant containing all the encoded streams is created.
981 ffmpeg -re -i in.ts -b:a:0 32k -b:a:1 64k -b:v:0 1000k \
982 -map 0:a -map 0:a -map 0:v -f hls \
983 -var_stream_map "a:0,agroup:aud_low,default:yes a:1,agroup:aud_low v:0,agroup:aud_low" \
984 -master_pl_name master.m3u8 \
985 http://example.com/live/out_%v.m3u8
987 This example creates two audio only and one video only variant streams. In
988 addition to the #EXT-X-STREAM-INF tag for each variant stream in the master
989 playlist, #EXT-X-MEDIA tag is also added for the two audio only variant streams
990 and they are mapped to the one video only variant streams with audio group name
991 'aud_low', and the audio group have default stat is NO or YES.
993 By default, a single hls variant containing all the encoded streams is created.
996 ffmpeg -re -i in.ts -b:a:0 32k -b:a:1 64k -b:v:0 1000k \
997 -map 0:a -map 0:a -map 0:v -f hls \
998 -var_stream_map "a:0,agroup:aud_low,default:yes,language:ENG a:1,agroup:aud_low,language:CHN v:0,agroup:aud_low" \
999 -master_pl_name master.m3u8 \
1000 http://example.com/live/out_%v.m3u8
1002 This example creates two audio only and one video only variant streams. In
1003 addition to the #EXT-X-STREAM-INF tag for each variant stream in the master
1004 playlist, #EXT-X-MEDIA tag is also added for the two audio only variant streams
1005 and they are mapped to the one video only variant streams with audio group name
1006 'aud_low', and the audio group have default stat is NO or YES, and one audio
1007 have and language is named ENG, the other audio language is named CHN.
1009 By default, a single hls variant containing all the encoded streams is created.
1012 Map string which specifies different closed captions groups and their
1013 attributes. The closed captions stream groups are separated by space.
1014 Expected string format is like this
1015 "ccgroup:<group name>,instreamid:<INSTREAM-ID>,language:<language code> ....".
1016 'ccgroup' and 'instreamid' are mandatory attributes. 'language' is an optional
1018 The closed captions groups configured using this option are mapped to different
1019 variant streams by providing the same 'ccgroup' name in the
1020 @code{var_stream_map} string. If @code{var_stream_map} is not set, then the
1021 first available ccgroup in @code{cc_stream_map} is mapped to the output variant
1022 stream. The examples for these two use cases are given below.
1025 ffmpeg -re -i in.ts -b:v 1000k -b:a 64k -a53cc 1 -f hls \
1026 -cc_stream_map "ccgroup:cc,instreamid:CC1,language:en" \
1027 -master_pl_name master.m3u8 \
1028 http://example.com/live/out.m3u8
1030 This example adds @code{#EXT-X-MEDIA} tag with @code{TYPE=CLOSED-CAPTIONS} in
1031 the master playlist with group name 'cc', language 'en' (english) and
1032 INSTREAM-ID 'CC1'. Also, it adds @code{CLOSED-CAPTIONS} attribute with group
1033 name 'cc' for the output variant stream.
1035 ffmpeg -re -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k -b:a:1 32k \
1036 -a53cc:0 1 -a53cc:1 1\
1037 -map 0:v -map 0:a -map 0:v -map 0:a -f hls \
1038 -cc_stream_map "ccgroup:cc,instreamid:CC1,language:en ccgroup:cc,instreamid:CC2,language:sp" \
1039 -var_stream_map "v:0,a:0,ccgroup:cc v:1,a:1,ccgroup:cc" \
1040 -master_pl_name master.m3u8 \
1041 http://example.com/live/out_%v.m3u8
1043 This example adds two @code{#EXT-X-MEDIA} tags with @code{TYPE=CLOSED-CAPTIONS} in
1044 the master playlist for the INSTREAM-IDs 'CC1' and 'CC2'. Also, it adds
1045 @code{CLOSED-CAPTIONS} attribute with group name 'cc' for the two output variant
1048 @item master_pl_name
1049 Create HLS master playlist with the given name.
1052 ffmpeg -re -i in.ts -f hls -master_pl_name master.m3u8 http://example.com/live/out.m3u8
1054 This example creates HLS master playlist with name master.m3u8 and it is
1055 published at http://example.com/live/
1057 @item master_pl_publish_rate
1058 Publish master play list repeatedly every after specified number of segment intervals.
1061 ffmpeg -re -i in.ts -f hls -master_pl_name master.m3u8 \
1062 -hls_time 2 -master_pl_publish_rate 30 http://example.com/live/out.m3u8
1065 This example creates HLS master playlist with name master.m3u8 and keep
1066 publishing it repeatedly every after 30 segments i.e. every after 60s.
1068 @item http_persistent
1069 Use persistent HTTP connections. Applicable only for HTTP output.
1072 Set timeout for socket I/O operations. Applicable only for HTTP output.
1074 @item -ignore_io_errors
1075 Ignore IO errors during open, write and delete. Useful for long-duration runs with network output.
1084 Microsoft's icon file format (ICO) has some strict limitations that should be noted:
1088 Size cannot exceed 256 pixels in any dimension
1091 Only BMP and PNG images can be stored
1094 If a BMP image is used, it must be one of the following pixel formats:
1096 BMP Bit Depth FFmpeg Pixel Format
1106 If a BMP image is used, it must use the BITMAPINFOHEADER DIB header
1109 If a PNG image is used, it must use the rgba pixel format
1117 The image file muxer writes video frames to image files.
1119 The output filenames are specified by a pattern, which can be used to
1120 produce sequentially numbered series of files.
1121 The pattern may contain the string "%d" or "%0@var{N}d", this string
1122 specifies the position of the characters representing a numbering in
1123 the filenames. If the form "%0@var{N}d" is used, the string
1124 representing the number in each filename is 0-padded to @var{N}
1125 digits. The literal character '%' can be specified in the pattern with
1128 If the pattern contains "%d" or "%0@var{N}d", the first filename of
1129 the file list specified will contain the number 1, all the following
1130 numbers will be sequential.
1132 The pattern may contain a suffix which is used to automatically
1133 determine the format of the image files to write.
1135 For example the pattern "img-%03d.bmp" will specify a sequence of
1136 filenames of the form @file{img-001.bmp}, @file{img-002.bmp}, ...,
1137 @file{img-010.bmp}, etc.
1138 The pattern "img%%-%d.jpg" will specify a sequence of filenames of the
1139 form @file{img%-1.jpg}, @file{img%-2.jpg}, ..., @file{img%-10.jpg},
1142 @subsection Examples
1144 The following example shows how to use @command{ffmpeg} for creating a
1145 sequence of files @file{img-001.jpeg}, @file{img-002.jpeg}, ...,
1146 taking one image every second from the input video:
1148 ffmpeg -i in.avi -vsync cfr -r 1 -f image2 'img-%03d.jpeg'
1151 Note that with @command{ffmpeg}, if the format is not specified with the
1152 @code{-f} option and the output filename specifies an image file
1153 format, the image2 muxer is automatically selected, so the previous
1154 command can be written as:
1156 ffmpeg -i in.avi -vsync cfr -r 1 'img-%03d.jpeg'
1159 Note also that the pattern must not necessarily contain "%d" or
1160 "%0@var{N}d", for example to create a single image file
1161 @file{img.jpeg} from the start of the input video you can employ the command:
1163 ffmpeg -i in.avi -f image2 -frames:v 1 img.jpeg
1166 The @option{strftime} option allows you to expand the filename with
1167 date and time information. Check the documentation of
1168 the @code{strftime()} function for the syntax.
1170 For example to generate image files from the @code{strftime()}
1171 "%Y-%m-%d_%H-%M-%S" pattern, the following @command{ffmpeg} command
1174 ffmpeg -f v4l2 -r 1 -i /dev/video0 -f image2 -strftime 1 "%Y-%m-%d_%H-%M-%S.jpg"
1177 You can set the file name with current frame's PTS:
1179 ffmpeg -f v4l2 -r 1 -i /dev/video0 -copyts -f image2 -frame_pts true %d.jpg"
1186 If set to 1, expand the filename with pts from pkt->pts.
1190 Start the sequence from the specified number. Default value is 1.
1193 If set to 1, the filename will always be interpreted as just a
1194 filename, not a pattern, and the corresponding file will be continuously
1195 overwritten with new images. Default value is 0.
1198 If set to 1, expand the filename with date and time information from
1199 @code{strftime()}. Default value is 0.
1202 The image muxer supports the .Y.U.V image file format. This format is
1203 special in that that each image frame consists of three files, for
1204 each of the YUV420P components. To read or write this image file format,
1205 specify the name of the '.Y' file. The muxer will automatically open the
1206 '.U' and '.V' files as required.
1210 Matroska container muxer.
1212 This muxer implements the matroska and webm container specs.
1214 @subsection Metadata
1216 The recognized metadata settings in this muxer are:
1220 Set title name provided to a single track.
1223 Specify the language of the track in the Matroska languages form.
1225 The language can be either the 3 letters bibliographic ISO-639-2 (ISO
1226 639-2/B) form (like "fre" for French), or a language code mixed with a
1227 country code for specialities in languages (like "fre-ca" for Canadian
1231 Set stereo 3D video layout of two views in a single video track.
1233 The following values are recognized:
1238 Both views are arranged side by side, Left-eye view is on the left
1240 Both views are arranged in top-bottom orientation, Left-eye view is at bottom
1242 Both views are arranged in top-bottom orientation, Left-eye view is on top
1243 @item checkerboard_rl
1244 Each view is arranged in a checkerboard interleaved pattern, Left-eye view being first
1245 @item checkerboard_lr
1246 Each view is arranged in a checkerboard interleaved pattern, Right-eye view being first
1247 @item row_interleaved_rl
1248 Each view is constituted by a row based interleaving, Right-eye view is first row
1249 @item row_interleaved_lr
1250 Each view is constituted by a row based interleaving, Left-eye view is first row
1251 @item col_interleaved_rl
1252 Both views are arranged in a column based interleaving manner, Right-eye view is first column
1253 @item col_interleaved_lr
1254 Both views are arranged in a column based interleaving manner, Left-eye view is first column
1255 @item anaglyph_cyan_red
1256 All frames are in anaglyph format viewable through red-cyan filters
1258 Both views are arranged side by side, Right-eye view is on the left
1259 @item anaglyph_green_magenta
1260 All frames are in anaglyph format viewable through green-magenta filters
1262 Both eyes laced in one Block, Left-eye view is first
1264 Both eyes laced in one Block, Right-eye view is first
1268 For example a 3D WebM clip can be created using the following command line:
1270 ffmpeg -i sample_left_right_clip.mpg -an -c:v libvpx -metadata stereo_mode=left_right -y stereo_clip.webm
1275 This muxer supports the following options:
1278 @item reserve_index_space
1279 By default, this muxer writes the index for seeking (called cues in Matroska
1280 terms) at the end of the file, because it cannot know in advance how much space
1281 to leave for the index at the beginning of the file. However for some use cases
1282 -- e.g. streaming where seeking is possible but slow -- it is useful to put the
1283 index at the beginning of the file.
1285 If this option is set to a non-zero value, the muxer will reserve a given amount
1286 of space in the file header and then try to write the cues there when the muxing
1287 finishes. If the available space does not suffice, muxing will fail. A safe size
1288 for most use cases should be about 50kB per hour of video.
1290 Note that cues are only written if the output is seekable and this option will
1291 have no effect if it is not.
1299 This is a variant of the @ref{hash} muxer. Unlike that muxer, it
1300 defaults to using the MD5 hash function.
1302 @subsection Examples
1304 To compute the MD5 hash of the input converted to raw
1305 audio and video, and store it in the file @file{out.md5}:
1307 ffmpeg -i INPUT -f md5 out.md5
1310 You can print the MD5 to stdout with the command:
1312 ffmpeg -i INPUT -f md5 -
1315 See also the @ref{hash} and @ref{framemd5} muxers.
1317 @section mov, mp4, ismv
1319 MOV/MP4/ISMV (Smooth Streaming) muxer.
1321 The mov/mp4/ismv muxer supports fragmentation. Normally, a MOV/MP4
1322 file has all the metadata about all packets stored in one location
1323 (written at the end of the file, it can be moved to the start for
1324 better playback by adding @var{faststart} to the @var{movflags}, or
1325 using the @command{qt-faststart} tool). A fragmented
1326 file consists of a number of fragments, where packets and metadata
1327 about these packets are stored together. Writing a fragmented
1328 file has the advantage that the file is decodable even if the
1329 writing is interrupted (while a normal MOV/MP4 is undecodable if
1330 it is not properly finished), and it requires less memory when writing
1331 very long files (since writing normal MOV/MP4 files stores info about
1332 every single packet in memory until the file is closed). The downside
1333 is that it is less compatible with other applications.
1337 Fragmentation is enabled by setting one of the AVOptions that define
1338 how to cut the file into fragments:
1341 @item -moov_size @var{bytes}
1342 Reserves space for the moov atom at the beginning of the file instead of placing the
1343 moov atom at the end. If the space reserved is insufficient, muxing will fail.
1344 @item -movflags frag_keyframe
1345 Start a new fragment at each video keyframe.
1346 @item -frag_duration @var{duration}
1347 Create fragments that are @var{duration} microseconds long.
1348 @item -frag_size @var{size}
1349 Create fragments that contain up to @var{size} bytes of payload data.
1350 @item -movflags frag_custom
1351 Allow the caller to manually choose when to cut fragments, by
1352 calling @code{av_write_frame(ctx, NULL)} to write a fragment with
1353 the packets written so far. (This is only useful with other
1354 applications integrating libavformat, not from @command{ffmpeg}.)
1355 @item -min_frag_duration @var{duration}
1356 Don't create fragments that are shorter than @var{duration} microseconds long.
1359 If more than one condition is specified, fragments are cut when
1360 one of the specified conditions is fulfilled. The exception to this is
1361 @code{-min_frag_duration}, which has to be fulfilled for any of the other
1362 conditions to apply.
1364 Additionally, the way the output file is written can be adjusted
1365 through a few other options:
1368 @item -movflags empty_moov
1369 Write an initial moov atom directly at the start of the file, without
1370 describing any samples in it. Generally, an mdat/moov pair is written
1371 at the start of the file, as a normal MOV/MP4 file, containing only
1372 a short portion of the file. With this option set, there is no initial
1373 mdat atom, and the moov atom only describes the tracks but has
1376 This option is implicitly set when writing ismv (Smooth Streaming) files.
1377 @item -movflags separate_moof
1378 Write a separate moof (movie fragment) atom for each track. Normally,
1379 packets for all tracks are written in a moof atom (which is slightly
1380 more efficient), but with this option set, the muxer writes one moof/mdat
1381 pair for each track, making it easier to separate tracks.
1383 This option is implicitly set when writing ismv (Smooth Streaming) files.
1384 @item -movflags skip_sidx
1385 Skip writing of sidx atom. When bitrate overhead due to sidx atom is high,
1386 this option could be used for cases where sidx atom is not mandatory.
1387 When global_sidx flag is enabled, this option will be ignored.
1388 @item -movflags faststart
1389 Run a second pass moving the index (moov atom) to the beginning of the file.
1390 This operation can take a while, and will not work in various situations such
1391 as fragmented output, thus it is not enabled by default.
1392 @item -movflags rtphint
1393 Add RTP hinting tracks to the output file.
1394 @item -movflags disable_chpl
1395 Disable Nero chapter markers (chpl atom). Normally, both Nero chapters
1396 and a QuickTime chapter track are written to the file. With this option
1397 set, only the QuickTime chapter track will be written. Nero chapters can
1398 cause failures when the file is reprocessed with certain tagging programs, like
1399 mp3Tag 2.61a and iTunes 11.3, most likely other versions are affected as well.
1400 @item -movflags omit_tfhd_offset
1401 Do not write any absolute base_data_offset in tfhd atoms. This avoids
1402 tying fragments to absolute byte positions in the file/streams.
1403 @item -movflags default_base_moof
1404 Similarly to the omit_tfhd_offset, this flag avoids writing the
1405 absolute base_data_offset field in tfhd atoms, but does so by using
1406 the new default-base-is-moof flag instead. This flag is new from
1407 14496-12:2012. This may make the fragments easier to parse in certain
1408 circumstances (avoiding basing track fragment location calculations
1409 on the implicit end of the previous track fragment).
1411 Specify @code{on} to force writing a timecode track, @code{off} to disable it
1412 and @code{auto} to write a timecode track only for mov and mp4 output (default).
1413 @item -movflags negative_cts_offsets
1414 Enables utilization of version 1 of the CTTS box, in which the CTS offsets can
1415 be negative. This enables the initial sample to have DTS/CTS of zero, and
1416 reduces the need for edit lists for some cases such as video tracks with
1417 B-frames. Additionally, eases conformance with the DASH-IF interoperability
1420 This option is implicitly set when writing ismv (Smooth Streaming) files.
1422 Write producer time reference box (PRFT) with a specified time source for the
1423 NTP field in the PRFT box. Set value as @samp{wallclock} to specify timesource
1424 as wallclock time and @samp{pts} to specify timesource as input packets' PTS
1427 Setting value to @samp{pts} is applicable only for a live encoding use case,
1428 where PTS values are set as as wallclock time at the source. For example, an
1429 encoding use case with decklink capture source where @option{video_pts} and
1430 @option{audio_pts} are set to @samp{abs_wallclock}.
1435 Smooth Streaming content can be pushed in real time to a publishing
1436 point on IIS with this muxer. Example:
1438 ffmpeg -re @var{<normal input/transcoding options>} -movflags isml+frag_keyframe -f ismv http://server/publishingpoint.isml/Streams(Encoder1)
1441 @subsection Audible AAX
1443 Audible AAX files are encrypted M4B files, and they can be decrypted by specifying a 4 byte activation secret.
1445 ffmpeg -activation_bytes 1CEB00DA -i test.aax -vn -c:a copy output.mp4
1450 The MP3 muxer writes a raw MP3 stream with the following optional features:
1453 An ID3v2 metadata header at the beginning (enabled by default). Versions 2.3 and
1454 2.4 are supported, the @code{id3v2_version} private option controls which one is
1455 used (3 or 4). Setting @code{id3v2_version} to 0 disables the ID3v2 header
1458 The muxer supports writing attached pictures (APIC frames) to the ID3v2 header.
1459 The pictures are supplied to the muxer in form of a video stream with a single
1460 packet. There can be any number of those streams, each will correspond to a
1461 single APIC frame. The stream metadata tags @var{title} and @var{comment} map
1462 to APIC @var{description} and @var{picture type} respectively. See
1463 @url{http://id3.org/id3v2.4.0-frames} for allowed picture types.
1465 Note that the APIC frames must be written at the beginning, so the muxer will
1466 buffer the audio frames until it gets all the pictures. It is therefore advised
1467 to provide the pictures as soon as possible to avoid excessive buffering.
1470 A Xing/LAME frame right after the ID3v2 header (if present). It is enabled by
1471 default, but will be written only if the output is seekable. The
1472 @code{write_xing} private option can be used to disable it. The frame contains
1473 various information that may be useful to the decoder, like the audio duration
1477 A legacy ID3v1 tag at the end of the file (disabled by default). It may be
1478 enabled with the @code{write_id3v1} private option, but as its capabilities are
1479 very limited, its usage is not recommended.
1484 Write an mp3 with an ID3v2.3 header and an ID3v1 footer:
1486 ffmpeg -i INPUT -id3v2_version 3 -write_id3v1 1 out.mp3
1489 To attach a picture to an mp3 file select both the audio and the picture stream
1492 ffmpeg -i input.mp3 -i cover.png -c copy -map 0 -map 1
1493 -metadata:s:v title="Album cover" -metadata:s:v comment="Cover (Front)" out.mp3
1496 Write a "clean" MP3 without any extra features:
1498 ffmpeg -i input.wav -write_xing 0 -id3v2_version 0 out.mp3
1503 MPEG transport stream muxer.
1505 This muxer implements ISO 13818-1 and part of ETSI EN 300 468.
1507 The recognized metadata settings in mpegts muxer are @code{service_provider}
1508 and @code{service_name}. If they are not set the default for
1509 @code{service_provider} is @samp{FFmpeg} and the default for
1510 @code{service_name} is @samp{Service01}.
1514 The muxer options are:
1517 @item mpegts_transport_stream_id @var{integer}
1518 Set the @samp{transport_stream_id}. This identifies a transponder in DVB.
1519 Default is @code{0x0001}.
1521 @item mpegts_original_network_id @var{integer}
1522 Set the @samp{original_network_id}. This is unique identifier of a
1523 network in DVB. Its main use is in the unique identification of a service
1524 through the path @samp{Original_Network_ID, Transport_Stream_ID}. Default
1527 @item mpegts_service_id @var{integer}
1528 Set the @samp{service_id}, also known as program in DVB. Default is
1531 @item mpegts_service_type @var{integer}
1532 Set the program @samp{service_type}. Default is @code{digital_tv}.
1533 Accepts the following options:
1536 Any hexadecimal value between @code{0x01} and @code{0xff} as defined in
1541 Digital Radio service.
1544 @item advanced_codec_digital_radio
1545 Advanced Codec Digital Radio service.
1546 @item mpeg2_digital_hdtv
1547 MPEG2 Digital HDTV service.
1548 @item advanced_codec_digital_sdtv
1549 Advanced Codec Digital SDTV service.
1550 @item advanced_codec_digital_hdtv
1551 Advanced Codec Digital HDTV service.
1554 @item mpegts_pmt_start_pid @var{integer}
1555 Set the first PID for PMT. Default is @code{0x1000}. Max is @code{0x1f00}.
1557 @item mpegts_start_pid @var{integer}
1558 Set the first PID for data packets. Default is @code{0x0100}. Max is
1561 @item mpegts_m2ts_mode @var{boolean}
1562 Enable m2ts mode if set to @code{1}. Default value is @code{-1} which
1565 @item muxrate @var{integer}
1566 Set a constant muxrate. Default is VBR.
1568 @item pes_payload_size @var{integer}
1569 Set minimum PES packet payload in bytes. Default is @code{2930}.
1571 @item mpegts_flags @var{flags}
1572 Set mpegts flags. Accepts the following options:
1574 @item resend_headers
1575 Reemit PAT/PMT before writing the next packet.
1577 Use LATM packetization for AAC.
1578 @item pat_pmt_at_frames
1579 Reemit PAT and PMT at each video frame.
1581 Conform to System B (DVB) instead of System A (ATSC).
1582 @item initial_discontinuity
1583 Mark the initial packet of each stream as discontinuity.
1586 @item resend_headers @var{integer}
1587 Reemit PAT/PMT before writing the next packet. This option is deprecated:
1588 use @option{mpegts_flags} instead.
1590 @item mpegts_copyts @var{boolean}
1591 Preserve original timestamps, if value is set to @code{1}. Default value
1592 is @code{-1}, which results in shifting timestamps so that they start from 0.
1594 @item omit_video_pes_length @var{boolean}
1595 Omit the PES packet length for video packets. Default is @code{1} (true).
1597 @item pcr_period @var{integer}
1598 Override the default PCR retransmission time in milliseconds. Ignored if
1599 variable muxrate is selected. Default is @code{20}.
1601 @item pat_period @var{double}
1602 Maximum time in seconds between PAT/PMT tables.
1604 @item sdt_period @var{double}
1605 Maximum time in seconds between SDT tables.
1607 @item tables_version @var{integer}
1608 Set PAT, PMT and SDT version (default @code{0}, valid values are from 0 to 31, inclusively).
1609 This option allows updating stream structure so that standard consumer may
1610 detect the change. To do so, reopen output @code{AVFormatContext} (in case of API
1611 usage) or restart @command{ffmpeg} instance, cyclically changing
1612 @option{tables_version} value:
1615 ffmpeg -i source1.ts -codec copy -f mpegts -tables_version 0 udp://1.1.1.1:1111
1616 ffmpeg -i source2.ts -codec copy -f mpegts -tables_version 1 udp://1.1.1.1:1111
1618 ffmpeg -i source3.ts -codec copy -f mpegts -tables_version 31 udp://1.1.1.1:1111
1619 ffmpeg -i source1.ts -codec copy -f mpegts -tables_version 0 udp://1.1.1.1:1111
1620 ffmpeg -i source2.ts -codec copy -f mpegts -tables_version 1 udp://1.1.1.1:1111
1628 ffmpeg -i file.mpg -c copy \
1629 -mpegts_original_network_id 0x1122 \
1630 -mpegts_transport_stream_id 0x3344 \
1631 -mpegts_service_id 0x5566 \
1632 -mpegts_pmt_start_pid 0x1500 \
1633 -mpegts_start_pid 0x150 \
1634 -metadata service_provider="Some provider" \
1635 -metadata service_name="Some Channel" \
1639 @section mxf, mxf_d10, mxf_opatom
1645 The muxer options are:
1648 @item store_user_comments @var{bool}
1649 Set if user comments should be stored if available or never.
1650 IRT D-10 does not allow user comments. The default is thus to write them for
1651 mxf and mxf_opatom but not for mxf_d10
1658 This muxer does not generate any output file, it is mainly useful for
1659 testing or benchmarking purposes.
1661 For example to benchmark decoding with @command{ffmpeg} you can use the
1664 ffmpeg -benchmark -i INPUT -f null out.null
1667 Note that the above command does not read or write the @file{out.null}
1668 file, but specifying the output file is required by the @command{ffmpeg}
1671 Alternatively you can write the command as:
1673 ffmpeg -benchmark -i INPUT -f null -
1679 @item -syncpoints @var{flags}
1680 Change the syncpoint usage in nut:
1682 @item @var{default} use the normal low-overhead seeking aids.
1683 @item @var{none} do not use the syncpoints at all, reducing the overhead but making the stream non-seekable;
1684 Use of this option is not recommended, as the resulting files are very damage
1685 sensitive and seeking is not possible. Also in general the overhead from
1686 syncpoints is negligible. Note, -@code{write_index} 0 can be used to disable
1687 all growing data tables, allowing to mux endless streams with limited memory
1688 and without these disadvantages.
1689 @item @var{timestamped} extend the syncpoint with a wallclock field.
1691 The @var{none} and @var{timestamped} flags are experimental.
1692 @item -write_index @var{bool}
1693 Write index at the end, the default is to write an index.
1697 ffmpeg -i INPUT -f_strict experimental -syncpoints none - | processor
1702 Ogg container muxer.
1705 @item -page_duration @var{duration}
1706 Preferred page duration, in microseconds. The muxer will attempt to create
1707 pages that are approximately @var{duration} microseconds long. This allows the
1708 user to compromise between seek granularity and container overhead. The default
1709 is 1 second. A value of 0 will fill all segments, making pages as large as
1710 possible. A value of 1 will effectively use 1 packet-per-page in most
1711 situations, giving a small seek granularity at the cost of additional container
1713 @item -serial_offset @var{value}
1714 Serial value from which to set the streams serial number.
1715 Setting it to different and sufficiently large values ensures that the produced
1716 ogg files can be safely chained.
1721 @section segment, stream_segment, ssegment
1723 Basic stream segmenter.
1725 This muxer outputs streams to a number of separate files of nearly
1726 fixed duration. Output filename pattern can be set in a fashion
1727 similar to @ref{image2}, or by using a @code{strftime} template if
1728 the @option{strftime} option is enabled.
1730 @code{stream_segment} is a variant of the muxer used to write to
1731 streaming output formats, i.e. which do not require global headers,
1732 and is recommended for outputting e.g. to MPEG transport stream segments.
1733 @code{ssegment} is a shorter alias for @code{stream_segment}.
1735 Every segment starts with a keyframe of the selected reference stream,
1736 which is set through the @option{reference_stream} option.
1738 Note that if you want accurate splitting for a video file, you need to
1739 make the input key frames correspond to the exact splitting times
1740 expected by the segmenter, or the segment muxer will start the new
1741 segment with the key frame found next after the specified start
1744 The segment muxer works best with a single constant frame rate video.
1746 Optionally it can generate a list of the created segments, by setting
1747 the option @var{segment_list}. The list type is specified by the
1748 @var{segment_list_type} option. The entry filenames in the segment
1749 list are set by default to the basename of the corresponding segment
1752 See also the @ref{hls} muxer, which provides a more specific
1753 implementation for HLS segmentation.
1757 The segment muxer supports the following options:
1760 @item increment_tc @var{1|0}
1761 if set to @code{1}, increment timecode between each segment
1762 If this is selected, the input need to have
1763 a timecode in the first video stream. Default value is
1766 @item reference_stream @var{specifier}
1767 Set the reference stream, as specified by the string @var{specifier}.
1768 If @var{specifier} is set to @code{auto}, the reference is chosen
1769 automatically. Otherwise it must be a stream specifier (see the ``Stream
1770 specifiers'' chapter in the ffmpeg manual) which specifies the
1771 reference stream. The default value is @code{auto}.
1773 @item segment_format @var{format}
1774 Override the inner container format, by default it is guessed by the filename
1777 @item segment_format_options @var{options_list}
1778 Set output format options using a :-separated list of key=value
1779 parameters. Values containing the @code{:} special character must be
1782 @item segment_list @var{name}
1783 Generate also a listfile named @var{name}. If not specified no
1784 listfile is generated.
1786 @item segment_list_flags @var{flags}
1787 Set flags affecting the segment list generation.
1789 It currently supports the following flags:
1792 Allow caching (only affects M3U8 list files).
1795 Allow live-friendly file generation.
1798 @item segment_list_size @var{size}
1799 Update the list file so that it contains at most @var{size}
1800 segments. If 0 the list file will contain all the segments. Default
1803 @item segment_list_entry_prefix @var{prefix}
1804 Prepend @var{prefix} to each entry. Useful to generate absolute paths.
1805 By default no prefix is applied.
1807 @item segment_list_type @var{type}
1808 Select the listing format.
1810 The following values are recognized:
1813 Generate a flat list for the created segments, one segment per line.
1816 Generate a list for the created segments, one segment per line,
1817 each line matching the format (comma-separated values):
1819 @var{segment_filename},@var{segment_start_time},@var{segment_end_time}
1822 @var{segment_filename} is the name of the output file generated by the
1823 muxer according to the provided pattern. CSV escaping (according to
1824 RFC4180) is applied if required.
1826 @var{segment_start_time} and @var{segment_end_time} specify
1827 the segment start and end time expressed in seconds.
1829 A list file with the suffix @code{".csv"} or @code{".ext"} will
1830 auto-select this format.
1832 @samp{ext} is deprecated in favor or @samp{csv}.
1835 Generate an ffconcat file for the created segments. The resulting file
1836 can be read using the FFmpeg @ref{concat} demuxer.
1838 A list file with the suffix @code{".ffcat"} or @code{".ffconcat"} will
1839 auto-select this format.
1842 Generate an extended M3U8 file, version 3, compliant with
1843 @url{http://tools.ietf.org/id/draft-pantos-http-live-streaming}.
1845 A list file with the suffix @code{".m3u8"} will auto-select this format.
1848 If not specified the type is guessed from the list file name suffix.
1850 @item segment_time @var{time}
1851 Set segment duration to @var{time}, the value must be a duration
1852 specification. Default value is "2". See also the
1853 @option{segment_times} option.
1855 Note that splitting may not be accurate, unless you force the
1856 reference stream key-frames at the given time. See the introductory
1857 notice and the examples below.
1859 @item segment_atclocktime @var{1|0}
1860 If set to "1" split at regular clock time intervals starting from 00:00
1861 o'clock. The @var{time} value specified in @option{segment_time} is
1862 used for setting the length of the splitting interval.
1864 For example with @option{segment_time} set to "900" this makes it possible
1865 to create files at 12:00 o'clock, 12:15, 12:30, etc.
1867 Default value is "0".
1869 @item segment_clocktime_offset @var{duration}
1870 Delay the segment splitting times with the specified duration when using
1871 @option{segment_atclocktime}.
1873 For example with @option{segment_time} set to "900" and
1874 @option{segment_clocktime_offset} set to "300" this makes it possible to
1875 create files at 12:05, 12:20, 12:35, etc.
1877 Default value is "0".
1879 @item segment_clocktime_wrap_duration @var{duration}
1880 Force the segmenter to only start a new segment if a packet reaches the muxer
1881 within the specified duration after the segmenting clock time. This way you
1882 can make the segmenter more resilient to backward local time jumps, such as
1883 leap seconds or transition to standard time from daylight savings time.
1885 Default is the maximum possible duration which means starting a new segment
1886 regardless of the elapsed time since the last clock time.
1888 @item segment_time_delta @var{delta}
1889 Specify the accuracy time when selecting the start time for a
1890 segment, expressed as a duration specification. Default value is "0".
1892 When delta is specified a key-frame will start a new segment if its
1893 PTS satisfies the relation:
1895 PTS >= start_time - time_delta
1898 This option is useful when splitting video content, which is always
1899 split at GOP boundaries, in case a key frame is found just before the
1900 specified split time.
1902 In particular may be used in combination with the @file{ffmpeg} option
1903 @var{force_key_frames}. The key frame times specified by
1904 @var{force_key_frames} may not be set accurately because of rounding
1905 issues, with the consequence that a key frame time may result set just
1906 before the specified time. For constant frame rate videos a value of
1907 1/(2*@var{frame_rate}) should address the worst case mismatch between
1908 the specified time and the time set by @var{force_key_frames}.
1910 @item segment_times @var{times}
1911 Specify a list of split points. @var{times} contains a list of comma
1912 separated duration specifications, in increasing order. See also
1913 the @option{segment_time} option.
1915 @item segment_frames @var{frames}
1916 Specify a list of split video frame numbers. @var{frames} contains a
1917 list of comma separated integer numbers, in increasing order.
1919 This option specifies to start a new segment whenever a reference
1920 stream key frame is found and the sequential number (starting from 0)
1921 of the frame is greater or equal to the next value in the list.
1923 @item segment_wrap @var{limit}
1924 Wrap around segment index once it reaches @var{limit}.
1926 @item segment_start_number @var{number}
1927 Set the sequence number of the first segment. Defaults to @code{0}.
1929 @item strftime @var{1|0}
1930 Use the @code{strftime} function to define the name of the new
1931 segments to write. If this is selected, the output segment name must
1932 contain a @code{strftime} function template. Default value is
1935 @item break_non_keyframes @var{1|0}
1936 If enabled, allow segments to start on frames other than keyframes. This
1937 improves behavior on some players when the time between keyframes is
1938 inconsistent, but may make things worse on others, and can cause some oddities
1939 during seeking. Defaults to @code{0}.
1941 @item reset_timestamps @var{1|0}
1942 Reset timestamps at the beginning of each segment, so that each segment
1943 will start with near-zero timestamps. It is meant to ease the playback
1944 of the generated segments. May not work with some combinations of
1945 muxers/codecs. It is set to @code{0} by default.
1947 @item initial_offset @var{offset}
1948 Specify timestamp offset to apply to the output packet timestamps. The
1949 argument must be a time duration specification, and defaults to 0.
1951 @item write_empty_segments @var{1|0}
1952 If enabled, write an empty segment if there are no packets during the period a
1953 segment would usually span. Otherwise, the segment will be filled with the next
1954 packet written. Defaults to @code{0}.
1957 Make sure to require a closed GOP when encoding and to set the GOP
1958 size to fit your segment time constraint.
1960 @subsection Examples
1964 Remux the content of file @file{in.mkv} to a list of segments
1965 @file{out-000.nut}, @file{out-001.nut}, etc., and write the list of
1966 generated segments to @file{out.list}:
1968 ffmpeg -i in.mkv -codec hevc -flags +cgop -g 60 -map 0 -f segment -segment_list out.list out%03d.nut
1972 Segment input and set output format options for the output segments:
1974 ffmpeg -i in.mkv -f segment -segment_time 10 -segment_format_options movflags=+faststart out%03d.mp4
1978 Segment the input file according to the split points specified by the
1979 @var{segment_times} option:
1981 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
1985 Use the @command{ffmpeg} @option{force_key_frames}
1986 option to force key frames in the input at the specified location, together
1987 with the segment option @option{segment_time_delta} to account for
1988 possible roundings operated when setting key frame times.
1990 ffmpeg -i in.mkv -force_key_frames 1,2,3,5,8,13,21 -codec:v mpeg4 -codec:a pcm_s16le -map 0 \
1991 -f segment -segment_list out.csv -segment_times 1,2,3,5,8,13,21 -segment_time_delta 0.05 out%03d.nut
1993 In order to force key frames on the input file, transcoding is
1997 Segment the input file by splitting the input file according to the
1998 frame numbers sequence specified with the @option{segment_frames} option:
2000 ffmpeg -i in.mkv -codec copy -map 0 -f segment -segment_list out.csv -segment_frames 100,200,300,500,800 out%03d.nut
2004 Convert the @file{in.mkv} to TS segments using the @code{libx264}
2005 and @code{aac} encoders:
2007 ffmpeg -i in.mkv -map 0 -codec:v libx264 -codec:a aac -f ssegment -segment_list out.list out%03d.ts
2011 Segment the input file, and create an M3U8 live playlist (can be used
2012 as live HLS source):
2014 ffmpeg -re -i in.mkv -codec copy -map 0 -f segment -segment_list playlist.m3u8 \
2015 -segment_list_flags +live -segment_time 10 out%03d.mkv
2019 @section smoothstreaming
2021 Smooth Streaming muxer generates a set of files (Manifest, chunks) suitable for serving with conventional web server.
2025 Specify the number of fragments kept in the manifest. Default 0 (keep all).
2027 @item extra_window_size
2028 Specify the number of fragments kept outside of the manifest before removing from disk. Default 5.
2030 @item lookahead_count
2031 Specify the number of lookahead fragments. Default 2.
2033 @item min_frag_duration
2034 Specify the minimum fragment duration (in microseconds). Default 5000000.
2036 @item remove_at_exit
2037 Specify whether to remove all fragments when finished. Default 0 (do not remove).
2044 The fifo pseudo-muxer allows the separation of encoding and muxing by using
2045 first-in-first-out queue and running the actual muxer in a separate thread. This
2046 is especially useful in combination with the @ref{tee} muxer and can be used to
2047 send data to several destinations with different reliability/writing speed/latency.
2049 API users should be aware that callback functions (interrupt_callback,
2050 io_open and io_close) used within its AVFormatContext must be thread-safe.
2052 The behavior of the fifo muxer if the queue fills up or if the output fails is
2058 output can be transparently restarted with configurable delay between retries
2059 based on real time or time of the processed stream.
2062 encoding can be blocked during temporary failure, or continue transparently
2063 dropping packets in case fifo queue fills up.
2070 Specify the format name. Useful if it cannot be guessed from the
2074 Specify size of the queue (number of packets). Default value is 60.
2077 Specify format options for the underlying muxer. Muxer options can be specified
2078 as a list of @var{key}=@var{value} pairs separated by ':'.
2080 @item drop_pkts_on_overflow @var{bool}
2081 If set to 1 (true), in case the fifo queue fills up, packets will be dropped
2082 rather than blocking the encoder. This makes it possible to continue streaming without
2083 delaying the input, at the cost of omitting part of the stream. By default
2084 this option is set to 0 (false), so in such cases the encoder will be blocked
2085 until the muxer processes some of the packets and none of them is lost.
2087 @item attempt_recovery @var{bool}
2088 If failure occurs, attempt to recover the output. This is especially useful
2089 when used with network output, since it makes it possible to restart streaming transparently.
2090 By default this option is set to 0 (false).
2092 @item max_recovery_attempts
2093 Sets maximum number of successive unsuccessful recovery attempts after which
2094 the output fails permanently. By default this option is set to 0 (unlimited).
2096 @item recovery_wait_time @var{duration}
2097 Waiting time before the next recovery attempt after previous unsuccessful
2098 recovery attempt. Default value is 5 seconds.
2100 @item recovery_wait_streamtime @var{bool}
2101 If set to 0 (false), the real time is used when waiting for the recovery
2102 attempt (i.e. the recovery will be attempted after at least
2103 recovery_wait_time seconds).
2104 If set to 1 (true), the time of the processed stream is taken into account
2105 instead (i.e. the recovery will be attempted after at least @var{recovery_wait_time}
2106 seconds of the stream is omitted).
2107 By default, this option is set to 0 (false).
2109 @item recover_any_error @var{bool}
2110 If set to 1 (true), recovery will be attempted regardless of type of the error
2111 causing the failure. By default this option is set to 0 (false) and in case of
2112 certain (usually permanent) errors the recovery is not attempted even when
2113 @var{attempt_recovery} is set to 1.
2115 @item restart_with_keyframe @var{bool}
2116 Specify whether to wait for the keyframe after recovering from
2117 queue overflow or failure. This option is set to 0 (false) by default.
2121 @subsection Examples
2126 Stream something to rtmp server, continue processing the stream at real-time
2127 rate even in case of temporary failure (network outage) and attempt to recover
2128 streaming every second indefinitely.
2130 ffmpeg -re -i ... -c:v libx264 -c:a aac -f fifo -fifo_format flv -map 0:v -map 0:a
2131 -drop_pkts_on_overflow 1 -attempt_recovery 1 -recovery_wait_time 1 rtmp://example.com/live/stream_name
2139 The tee muxer can be used to write the same data to several outputs, such as files or streams.
2140 It can be used, for example, to stream a video over a network and save it to disk at the same time.
2142 It is different from specifying several outputs to the @command{ffmpeg}
2143 command-line tool. With the tee muxer, the audio and video data will be encoded only once.
2144 With conventional multiple outputs, multiple encoding operations in parallel are initiated,
2145 which can be a very expensive process. The tee muxer is not useful when using the libavformat API
2146 directly because it is then possible to feed the same packets to several muxers directly.
2148 Since the tee muxer does not represent any particular output format, ffmpeg cannot auto-select
2149 output streams. So all streams intended for output must be specified using @code{-map}. See
2152 Some encoders may need different options depending on the output format;
2153 the auto-detection of this can not work with the tee muxer, so they need to be explicitly specified.
2154 The main example is the @option{global_header} flag.
2156 The slave outputs are specified in the file name given to the muxer,
2157 separated by '|'. If any of the slave name contains the '|' separator,
2158 leading or trailing spaces or any special character, those must be
2159 escaped (see @ref{quoting_and_escaping,,the "Quoting and escaping"
2160 section in the ffmpeg-utils(1) manual,ffmpeg-utils}).
2166 @item use_fifo @var{bool}
2167 If set to 1, slave outputs will be processed in separate threads using the @ref{fifo}
2168 muxer. This allows to compensate for different speed/latency/reliability of
2169 outputs and setup transparent recovery. By default this feature is turned off.
2172 Options to pass to fifo pseudo-muxer instances. See @ref{fifo}.
2176 Muxer options can be specified for each slave by prepending them as a list of
2177 @var{key}=@var{value} pairs separated by ':', between square brackets. If
2178 the options values contain a special character or the ':' separator, they
2179 must be escaped; note that this is a second level escaping.
2181 The following special options are also recognized:
2184 Specify the format name. Required if it cannot be guessed from the
2187 @item bsfs[/@var{spec}]
2188 Specify a list of bitstream filters to apply to the specified
2191 It is possible to specify to which streams a given bitstream filter
2192 applies, by appending a stream specifier to the option separated by
2193 @code{/}. @var{spec} must be a stream specifier (see @ref{Format
2194 stream specifiers}).
2196 If the stream specifier is not specified, the bitstream filters will be
2197 applied to all streams in the output. This will cause that output operation
2198 to fail if the output contains streams to which the bitstream filter cannot
2199 be applied e.g. @code{h264_mp4toannexb} being applied to an output containing an audio stream.
2201 Options for a bitstream filter must be specified in the form of @code{opt=value}.
2203 Several bitstream filters can be specified, separated by ",".
2205 @item use_fifo @var{bool}
2206 This allows to override tee muxer use_fifo option for individual slave muxer.
2209 This allows to override tee muxer fifo_options for individual slave muxer.
2213 Select the streams that should be mapped to the slave output,
2214 specified by a stream specifier. If not specified, this defaults to
2215 all the mapped streams. This will cause that output operation to fail
2216 if the output format does not accept all mapped streams.
2218 You may use multiple stream specifiers separated by commas (@code{,}) e.g.: @code{a:0,v}
2221 Specify behaviour on output failure. This can be set to either @code{abort} (which is
2222 default) or @code{ignore}. @code{abort} will cause whole process to fail in case of failure
2223 on this slave output. @code{ignore} will ignore failure on this output, so other outputs
2224 will continue without being affected.
2227 @subsection Examples
2231 Encode something and both archive it in a WebM file and stream it
2232 as MPEG-TS over UDP:
2234 ffmpeg -i ... -c:v libx264 -c:a mp2 -f tee -map 0:v -map 0:a
2235 "archive-20121107.mkv|[f=mpegts]udp://10.0.1.255:1234/"
2239 As above, but continue streaming even if output to local file fails
2240 (for example local drive fills up):
2242 ffmpeg -i ... -c:v libx264 -c:a mp2 -f tee -map 0:v -map 0:a
2243 "[onfail=ignore]archive-20121107.mkv|[f=mpegts]udp://10.0.1.255:1234/"
2247 Use @command{ffmpeg} to encode the input, and send the output
2248 to three different destinations. The @code{dump_extra} bitstream
2249 filter is used to add extradata information to all the output video
2250 keyframes packets, as requested by the MPEG-TS format. The select
2251 option is applied to @file{out.aac} in order to make it contain only
2254 ffmpeg -i ... -map 0 -flags +global_header -c:v libx264 -c:a aac
2255 -f tee "[bsfs/v=dump_extra=freq=keyframe]out.ts|[movflags=+faststart]out.mp4|[select=a]out.aac"
2259 As above, but select only stream @code{a:1} for the audio output. Note
2260 that a second level escaping must be performed, as ":" is a special
2261 character used to separate options.
2263 ffmpeg -i ... -map 0 -flags +global_header -c:v libx264 -c:a aac
2264 -f tee "[bsfs/v=dump_extra=freq=keyframe]out.ts|[movflags=+faststart]out.mp4|[select=\'a:1\']out.aac"
2268 @section webm_dash_manifest
2270 WebM DASH Manifest muxer.
2272 This muxer implements the WebM DASH Manifest specification to generate the DASH
2273 manifest XML. It also supports manifest generation for DASH live streams.
2275 For more information see:
2279 WebM DASH Specification: @url{https://sites.google.com/a/webmproject.org/wiki/adaptive-streaming/webm-dash-specification}
2281 ISO DASH Specification: @url{http://standards.iso.org/ittf/PubliclyAvailableStandards/c065274_ISO_IEC_23009-1_2014.zip}
2286 This muxer supports the following options:
2289 @item adaptation_sets
2290 This option has the following syntax: "id=x,streams=a,b,c id=y,streams=d,e" where x and y are the
2291 unique identifiers of the adaptation sets and a,b,c,d and e are the indices of the corresponding
2292 audio and video streams. Any number of adaptation sets can be added using this option.
2295 Set this to 1 to create a live stream DASH Manifest. Default: 0.
2297 @item chunk_start_index
2298 Start index of the first chunk. This will go in the @samp{startNumber} attribute
2299 of the @samp{SegmentTemplate} element in the manifest. Default: 0.
2301 @item chunk_duration_ms
2302 Duration of each chunk in milliseconds. This will go in the @samp{duration}
2303 attribute of the @samp{SegmentTemplate} element in the manifest. Default: 1000.
2305 @item utc_timing_url
2306 URL of the page that will return the UTC timestamp in ISO format. This will go
2307 in the @samp{value} attribute of the @samp{UTCTiming} element in the manifest.
2310 @item time_shift_buffer_depth
2311 Smallest time (in seconds) shifting buffer for which any Representation is
2312 guaranteed to be available. This will go in the @samp{timeShiftBufferDepth}
2313 attribute of the @samp{MPD} element. Default: 60.
2315 @item minimum_update_period
2316 Minimum update period (in seconds) of the manifest. This will go in the
2317 @samp{minimumUpdatePeriod} attribute of the @samp{MPD} element. Default: 0.
2323 ffmpeg -f webm_dash_manifest -i video1.webm \
2324 -f webm_dash_manifest -i video2.webm \
2325 -f webm_dash_manifest -i audio1.webm \
2326 -f webm_dash_manifest -i audio2.webm \
2327 -map 0 -map 1 -map 2 -map 3 \
2329 -f webm_dash_manifest \
2330 -adaptation_sets "id=0,streams=0,1 id=1,streams=2,3" \
2336 WebM Live Chunk Muxer.
2338 This muxer writes out WebM headers and chunks as separate files which can be
2339 consumed by clients that support WebM Live streams via DASH.
2343 This muxer supports the following options:
2346 @item chunk_start_index
2347 Index of the first chunk (defaults to 0).
2350 Filename of the header where the initialization data will be written.
2352 @item audio_chunk_duration
2353 Duration of each audio chunk in milliseconds (defaults to 5000).
2358 ffmpeg -f v4l2 -i /dev/video0 \
2362 -s 640x360 -keyint_min 30 -g 30 \
2364 -header webm_live_video_360.hdr \
2365 -chunk_start_index 1 \
2366 webm_live_video_360_%d.chk \
2371 -header webm_live_audio_128.hdr \
2372 -chunk_start_index 1 \
2373 -audio_chunk_duration 1000 \
2374 webm_live_audio_128_%d.chk