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.
279 Optional syntax is "id=x,descriptor=descriptor_string,streams=a,b,c id=y,streams=d,e" and so on, descriptor is useful to the scheme defined by ISO/IEC 23009-1:2014/Amd.2:2015.
280 For example, -adaptation_sets "id=0,descriptor=<SupplementalProperty schemeIdUri=\"urn:mpeg:dash:srd:2014\" value=\"0,0,0,1,1,2,2\"/>,streams=v".
281 Please note that descriptor string should be a self-closing xml tag.
282 @item timeout @var{timeout}
283 Set timeout for socket I/O operations. Applicable only for HTTP output.
284 @item index_correction @var{index_correction}
285 Enable (1) or Disable (0) segment index correction logic. Applicable only when
286 @var{use_template} is enabled and @var{use_timeline} is disabled.
288 When enabled, the logic monitors the flow of segment indexes. If a streams's
289 segment index value is not at the expected real time position, then the logic
290 corrects that index value.
292 Typically this logic is needed in live streaming use cases. The network bandwidth
293 fluctuations are common during long run streaming. Each fluctuation can cause
294 the segment indexes fall behind the expected real time position.
295 @item format_options @var{options_list}
296 Set container format (mp4/webm) options using a @code{:} separated list of
297 key=value parameters. Values containing @code{:} special characters must be
300 @item global_sidx @var{global_sidx}
301 Write global SIDX atom. Applicable only for single file, mp4 output, non-streaming mode.
303 @item dash_segment_type @var{dash_segment_type}
307 If this flag is set, the dash segment files format will be selected based on the stream codec. This is the default mode.
310 If this flag is set, the dash segment files will be in in ISOBMFF format.
313 If this flag is set, the dash segment files will be in in WebM format.
316 @item ignore_io_errors @var{ignore_io_errors}
317 Ignore IO errors during open and write. Useful for long-duration runs with network output.
319 @item lhls @var{lhls}
320 Enable Low-latency HLS(LHLS). Adds #EXT-X-PREFETCH tag with current segment's URI.
321 Apple doesn't have an official spec for LHLS. Meanwhile hls.js player folks are
322 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
323 This option will also try to comply with the above open spec, till Apple's spec officially supports it.
324 Applicable only when @var{streaming} and @var{hls_playlist} options are enabled.
325 This is an experimental feature.
327 @item master_m3u8_publish_rate @var{master_m3u8_publish_rate}
328 Publish master playlist repeatedly every after specified number of segment intervals.
335 Per-packet CRC (Cyclic Redundancy Check) testing format.
337 This muxer computes and prints the Adler-32 CRC for each audio
338 and video packet. By default audio frames are converted to signed
339 16-bit raw audio and video frames to raw video before computing the
342 The output of the muxer consists of a line for each audio and video
345 @var{stream_index}, @var{packet_dts}, @var{packet_pts}, @var{packet_duration}, @var{packet_size}, 0x@var{CRC}
348 @var{CRC} is a hexadecimal number 0-padded to 8 digits containing the
353 For example to compute the CRC of the audio and video frames in
354 @file{INPUT}, converted to raw audio and video packets, and store it
355 in the file @file{out.crc}:
357 ffmpeg -i INPUT -f framecrc out.crc
360 To print the information to stdout, use the command:
362 ffmpeg -i INPUT -f framecrc -
365 With @command{ffmpeg}, you can select the output format to which the
366 audio and video frames are encoded before computing the CRC for each
367 packet by specifying the audio and video codec. For example, to
368 compute the CRC of each decoded input audio frame converted to PCM
369 unsigned 8-bit and of each decoded input video frame converted to
370 MPEG-2 video, use the command:
372 ffmpeg -i INPUT -c:a pcm_u8 -c:v mpeg2video -f framecrc -
375 See also the @ref{crc} muxer.
380 Per-packet hash testing format.
382 This muxer computes and prints a cryptographic hash for each audio
383 and video packet. This can be used for packet-by-packet equality
384 checks without having to individually do a binary comparison on each.
386 By default audio frames are converted to signed 16-bit raw audio and
387 video frames to raw video before computing the hash, but the output
388 of explicit conversions to other codecs can also be used. It uses the
389 SHA-256 cryptographic hash function by default, but supports several
392 The output of the muxer consists of a line for each audio and video
395 @var{stream_index}, @var{packet_dts}, @var{packet_pts}, @var{packet_duration}, @var{packet_size}, @var{hash}
398 @var{hash} is a hexadecimal number representing the computed hash
402 @item hash @var{algorithm}
403 Use the cryptographic hash function specified by the string @var{algorithm}.
404 Supported values include @code{MD5}, @code{murmur3}, @code{RIPEMD128},
405 @code{RIPEMD160}, @code{RIPEMD256}, @code{RIPEMD320}, @code{SHA160},
406 @code{SHA224}, @code{SHA256} (default), @code{SHA512/224}, @code{SHA512/256},
407 @code{SHA384}, @code{SHA512}, @code{CRC32} and @code{adler32}.
413 To compute the SHA-256 hash of the audio and video frames in @file{INPUT},
414 converted to raw audio and video packets, and store it in the file
417 ffmpeg -i INPUT -f framehash out.sha256
420 To print the information to stdout, using the MD5 hash function, use
423 ffmpeg -i INPUT -f framehash -hash md5 -
426 See also the @ref{hash} muxer.
431 Per-packet MD5 testing format.
433 This is a variant of the @ref{framehash} muxer. Unlike that muxer,
434 it defaults to using the MD5 hash function.
438 To compute the MD5 hash of the audio and video frames in @file{INPUT},
439 converted to raw audio and video packets, and store it in the file
442 ffmpeg -i INPUT -f framemd5 out.md5
445 To print the information to stdout, use the command:
447 ffmpeg -i INPUT -f framemd5 -
450 See also the @ref{framehash} and @ref{md5} muxers.
457 It accepts the following options:
461 Set the number of times to loop the output. Use @code{-1} for no loop, @code{0}
462 for looping indefinitely (default).
465 Force the delay (expressed in centiseconds) after the last frame. Each frame
466 ends with a delay until the next frame. The default is @code{-1}, which is a
467 special value to tell the muxer to re-use the previous delay. In case of a
468 loop, you might want to customize this value to mark a pause for instance.
471 For example, to encode a gif looping 10 times, with a 5 seconds delay between
474 ffmpeg -i INPUT -loop 10 -final_delay 500 out.gif
477 Note 1: if you wish to extract the frames into separate GIF files, you need to
478 force the @ref{image2} muxer:
480 ffmpeg -i INPUT -c:v gif -f image2 "out%d.gif"
483 Note 2: the GIF format has a very large time base: the delay between two frames
484 can therefore not be smaller than one centi second.
491 This muxer computes and prints a cryptographic hash of all the input
492 audio and video frames. This can be used for equality checks without
493 having to do a complete binary comparison.
495 By default audio frames are converted to signed 16-bit raw audio and
496 video frames to raw video before computing the hash, but the output
497 of explicit conversions to other codecs can also be used. Timestamps
498 are ignored. It uses the SHA-256 cryptographic hash function by default,
499 but supports several other algorithms.
501 The output of the muxer consists of a single line of the form:
502 @var{algo}=@var{hash}, where @var{algo} is a short string representing
503 the hash function used, and @var{hash} is a hexadecimal number
504 representing the computed hash.
507 @item hash @var{algorithm}
508 Use the cryptographic hash function specified by the string @var{algorithm}.
509 Supported values include @code{MD5}, @code{murmur3}, @code{RIPEMD128},
510 @code{RIPEMD160}, @code{RIPEMD256}, @code{RIPEMD320}, @code{SHA160},
511 @code{SHA224}, @code{SHA256} (default), @code{SHA512/224}, @code{SHA512/256},
512 @code{SHA384}, @code{SHA512}, @code{CRC32} and @code{adler32}.
518 To compute the SHA-256 hash of the input converted to raw audio and
519 video, and store it in the file @file{out.sha256}:
521 ffmpeg -i INPUT -f hash out.sha256
524 To print an MD5 hash to stdout use the command:
526 ffmpeg -i INPUT -f hash -hash md5 -
529 See also the @ref{framehash} muxer.
534 Apple HTTP Live Streaming muxer that segments MPEG-TS according to
535 the HTTP Live Streaming (HLS) specification.
537 It creates a playlist file, and one or more segment files. The output filename
538 specifies the playlist filename.
540 By default, the muxer creates a file for each segment produced. These files
541 have the same name as the playlist, followed by a sequential number and a
544 Make sure to require a closed GOP when encoding and to set the GOP
545 size to fit your segment time constraint.
547 For example, to convert an input file with @command{ffmpeg}:
549 ffmpeg -i in.mkv -c:v h264 -flags +cgop -g 30 -hls_time 1 out.m3u8
551 This example will produce the playlist, @file{out.m3u8}, and segment files:
552 @file{out0.ts}, @file{out1.ts}, @file{out2.ts}, etc.
554 See also the @ref{segment} muxer, which provides a more generic and
555 flexible implementation of a segmenter, and can be used to perform HLS
560 This muxer supports the following options:
563 @item hls_init_time @var{seconds}
564 Set the initial target segment length in seconds. Default value is @var{0}.
565 Segment will be cut on the next key frame after this time has passed on the first m3u8 list.
566 After the initial playlist is filled @command{ffmpeg} will cut segments
567 at duration equal to @code{hls_time}
569 @item hls_time @var{seconds}
570 Set the target segment length in seconds. Default value is 2.
571 Segment will be cut on the next key frame after this time has passed.
573 @item hls_list_size @var{size}
574 Set the maximum number of playlist entries. If set to 0 the list file
575 will contain all the segments. Default value is 5.
577 @item hls_delete_threshold @var{size}
578 Set the number of unreferenced segments to keep on disk before @code{hls_flags delete_segments}
579 deletes them. Increase this to allow continue clients to download segments which
580 were recently referenced in the playlist. Default value is 1, meaning segments older than
581 @code{hls_list_size+1} will be deleted.
583 @item hls_ts_options @var{options_list}
584 Set output format options using a :-separated list of key=value
585 parameters. Values containing @code{:} special characters must be
588 @item hls_wrap @var{wrap}
589 This is a deprecated option, you can use @code{hls_list_size}
590 and @code{hls_flags delete_segments} instead it
592 This option is useful to avoid to fill the disk with many segment
593 files, and limits the maximum number of segment files written to disk
597 @item hls_start_number_source
598 Start the playlist sequence number (@code{#EXT-X-MEDIA-SEQUENCE}) according to the specified source.
599 Unless @code{hls_flags single_file} is set, it also specifies source of starting sequence numbers of
600 segment and subtitle filenames. In any case, if @code{hls_flags append_list}
601 is set and read playlist sequence number is greater than the specified start sequence number,
602 then that value will be used as start value.
604 It accepts the following values:
608 @item generic (default)
609 Set the starting sequence numbers according to @var{start_number} option value.
612 The start number will be the seconds since epoch (1970-01-01 00:00:00)
615 The start number will be based on the current date/time as YYYYmmddHHMMSS. e.g. 20161231235759.
619 @item start_number @var{number}
620 Start the playlist sequence number (@code{#EXT-X-MEDIA-SEQUENCE}) from the specified @var{number}
621 when @var{hls_start_number_source} value is @var{generic}. (This is the default case.)
622 Unless @code{hls_flags single_file} is set, it also specifies starting sequence numbers of segment and subtitle filenames.
625 @item hls_allow_cache @var{allowcache}
626 Explicitly set whether the client MAY (1) or MUST NOT (0) cache media segments.
628 @item hls_base_url @var{baseurl}
629 Append @var{baseurl} to every entry in the playlist.
630 Useful to generate playlists with absolute paths.
632 Note that the playlist sequence number must be unique for each segment
633 and it is not to be confused with the segment filename sequence number
634 which can be cyclic, for example if the @option{wrap} option is
637 @item hls_segment_filename @var{filename}
638 Set the segment filename. Unless @code{hls_flags single_file} is set,
639 @var{filename} is used as a string format with the segment number:
641 ffmpeg -i in.nut -hls_segment_filename 'file%03d.ts' out.m3u8
643 This example will produce the playlist, @file{out.m3u8}, and segment files:
644 @file{file000.ts}, @file{file001.ts}, @file{file002.ts}, etc.
646 @var{filename} may contain full path or relative path specification,
647 but only the file name part without any path info will be contained in the m3u8 segment list.
648 Should a relative path be specified, the path of the created segment
649 files will be relative to the current working directory.
650 When strftime_mkdir is set, the whole expanded value of @var{filename} will be written into the m3u8 segment list.
652 When @code{var_stream_map} is set with two or more variant streams, the
653 @var{filename} pattern must contain the string "%v", this string specifies
654 the position of variant stream index in the generated segment file names.
656 ffmpeg -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k -b:a:1 32k \
657 -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" \
658 -hls_segment_filename 'file_%v_%03d.ts' out_%v.m3u8
660 This example will produce the playlists segment file sets:
661 @file{file_0_000.ts}, @file{file_0_001.ts}, @file{file_0_002.ts}, etc. and
662 @file{file_1_000.ts}, @file{file_1_001.ts}, @file{file_1_002.ts}, etc.
664 The string "%v" may be present in the filename or in the last directory name
665 containing the file, but only in one of them. (Additionally, %v may appear multiple times in the last
666 sub-directory or filename.) If the string %v is present in the directory name, then
667 sub-directories are created after expanding the directory name pattern. This
668 enables creation of segments corresponding to different variant streams in
671 ffmpeg -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k -b:a:1 32k \
672 -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" \
673 -hls_segment_filename 'vs%v/file_%03d.ts' vs%v/out.m3u8
675 This example will produce the playlists segment file sets:
676 @file{vs0/file_000.ts}, @file{vs0/file_001.ts}, @file{vs0/file_002.ts}, etc. and
677 @file{vs1/file_000.ts}, @file{vs1/file_001.ts}, @file{vs1/file_002.ts}, etc.
680 Same as strftime option, will be deprecated.
683 Use strftime() on @var{filename} to expand the segment filename with localtime.
684 The segment number is also available in this mode, but to use it, you need to specify second_level_segment_index
685 hls_flag and %%d will be the specifier.
687 ffmpeg -i in.nut -strftime 1 -hls_segment_filename 'file-%Y%m%d-%s.ts' out.m3u8
689 This example will produce the playlist, @file{out.m3u8}, and segment files:
690 @file{file-20160215-1455569023.ts}, @file{file-20160215-1455569024.ts}, etc.
691 Note: On some systems/environments, the @code{%s} specifier is not available. See
692 @code{strftime()} documentation.
694 ffmpeg -i in.nut -strftime 1 -hls_flags second_level_segment_index -hls_segment_filename 'file-%Y%m%d-%%04d.ts' out.m3u8
696 This example will produce the playlist, @file{out.m3u8}, and segment files:
697 @file{file-20160215-0001.ts}, @file{file-20160215-0002.ts}, etc.
699 @item use_localtime_mkdir
700 Same as strftime_mkdir option, will be deprecated .
703 Used together with -strftime_mkdir, it will create all subdirectories which
704 is expanded in @var{filename}.
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 201560215 (if it does not exist), and then
709 produce the playlist, @file{out.m3u8}, and segment files:
710 @file{20160215/file-20160215-1455569023.ts}, @file{20160215/file-20160215-1455569024.ts}, etc.
713 ffmpeg -i in.nut -strftime 1 -strftime_mkdir 1 -hls_segment_filename '%Y/%m/%d/file-%Y%m%d-%s.ts' out.m3u8
715 This example will create a directory hierarchy 2016/02/15 (if any of them do not exist), and then
716 produce the playlist, @file{out.m3u8}, and segment files:
717 @file{2016/02/15/file-20160215-1455569023.ts}, @file{2016/02/15/file-20160215-1455569024.ts}, etc.
720 @item hls_key_info_file @var{key_info_file}
721 Use the information in @var{key_info_file} for segment encryption. The first
722 line of @var{key_info_file} specifies the key URI written to the playlist. The
723 key URL is used to access the encryption key during playback. The second line
724 specifies the path to the key file used to obtain the key during the encryption
725 process. The key file is read as a single packed array of 16 octets in binary
726 format. The optional third line specifies the initialization vector (IV) as a
727 hexadecimal string to be used instead of the segment sequence number (default)
728 for encryption. Changes to @var{key_info_file} will result in segment
729 encryption with the new key/IV and an entry in the playlist for the new key
730 URI/IV if @code{hls_flags periodic_rekey} is enabled.
732 Key info file format:
741 http://server/file.key
746 Example key file paths:
754 0123456789ABCDEF0123456789ABCDEF
757 Key info file example:
759 http://server/file.key
761 0123456789ABCDEF0123456789ABCDEF
764 Example shell script:
768 openssl rand 16 > file.key
769 echo $BASE_URL/file.key > file.keyinfo
770 echo file.key >> file.keyinfo
771 echo $(openssl rand -hex 16) >> file.keyinfo
772 ffmpeg -f lavfi -re -i testsrc -c:v h264 -hls_flags delete_segments \
773 -hls_key_info_file file.keyinfo out.m3u8
776 @item -hls_enc @var{enc}
777 Enable (1) or disable (0) the AES128 encryption.
778 When enabled every segment generated is encrypted and the encryption key
779 is saved as @var{playlist name}.key.
781 @item -hls_enc_key @var{key}
782 Hex-coded 16byte key to encrypt the segments, by default it
783 is randomly generated.
785 @item -hls_enc_key_url @var{keyurl}
786 If set, @var{keyurl} is prepended instead of @var{baseurl} to the key filename
789 @item -hls_enc_iv @var{iv}
790 Hex-coded 16byte initialization vector for every segment instead
791 of the autogenerated ones.
793 @item hls_segment_type @var{flags}
798 Output segment files in MPEG-2 Transport Stream format. This is
799 compatible with all HLS versions.
802 Output segment files in fragmented MP4 format, similar to MPEG-DASH.
803 fmp4 files may be used in HLS version 7 and above.
807 @item hls_fmp4_init_filename @var{filename}
808 Set filename to the fragment files header file, default filename is @file{init.mp4}.
810 When @code{var_stream_map} is set with two or more variant streams, the
811 @var{filename} pattern must contain the string "%v", this string specifies
812 the position of variant stream index in the generated init file names.
813 The string "%v" may be present in the filename or in the last directory name
814 containing the file. If the string is present in the directory name, then
815 sub-directories are created after expanding the directory name pattern. This
816 enables creation of init files corresponding to different variant streams in
819 @item hls_flags @var{flags}
824 If this flag is set, the muxer will store all segments in a single MPEG-TS
825 file, and will use byte ranges in the playlist. HLS playlists generated with
826 this way will have the version number 4.
829 ffmpeg -i in.nut -hls_flags single_file out.m3u8
831 Will produce the playlist, @file{out.m3u8}, and a single segment file,
834 @item delete_segments
835 Segment files removed from the playlist are deleted after a period of time
836 equal to the duration of the segment plus the duration of the playlist.
839 Append new segments into the end of old segment list,
840 and remove the @code{#EXT-X-ENDLIST} from the old segment list.
842 @item round_durations
843 Round the duration info in the playlist file segment info to integer
844 values, instead of using floating point.
847 Add the @code{#EXT-X-DISCONTINUITY} tag to the playlist, before the
848 first segment's information.
851 Do not append the @code{EXT-X-ENDLIST} tag at the end of the playlist.
854 The file specified by @code{hls_key_info_file} will be checked periodically and
855 detect updates to the encryption info. Be sure to replace this file atomically,
856 including the file containing the AES encryption key.
858 @item independent_segments
859 Add the @code{#EXT-X-INDEPENDENT-SEGMENTS} to playlists that has video segments
860 and when all the segments of that playlist are guaranteed to start with a Key frame.
863 Add the @code{#EXT-X-I-FRAMES-ONLY} to playlists that has video segments
864 and can play only I-frames in the @code{#EXT-X-BYTERANGE} mode.
867 Allow segments to start on frames other than keyframes. This improves
868 behavior on some players when the time between keyframes is inconsistent,
869 but may make things worse on others, and can cause some oddities during
870 seeking. This flag should be used with the @code{hls_time} option.
872 @item program_date_time
873 Generate @code{EXT-X-PROGRAM-DATE-TIME} tags.
875 @item second_level_segment_index
876 Makes it possible to use segment indexes as %%d in hls_segment_filename expression
877 besides date/time values when strftime is on.
878 To get fixed width numbers with trailing zeroes, %%0xd format is available where x is the required width.
880 @item second_level_segment_size
881 Makes it possible to use segment sizes (counted in bytes) as %%s in hls_segment_filename
882 expression besides date/time values when strftime is on.
883 To get fixed width numbers with trailing zeroes, %%0xs format is available where x is the required width.
885 @item second_level_segment_duration
886 Makes it possible to use segment duration (calculated in microseconds) as %%t in hls_segment_filename
887 expression besides date/time values when strftime is on.
888 To get fixed width numbers with trailing zeroes, %%0xt format is available where x is the required width.
891 ffmpeg -i sample.mpeg \
892 -f hls -hls_time 3 -hls_list_size 5 \
893 -hls_flags second_level_segment_index+second_level_segment_size+second_level_segment_duration \
894 -strftime 1 -strftime_mkdir 1 -hls_segment_filename "segment_%Y%m%d%H%M%S_%%04d_%%08s_%%013t.ts" stream.m3u8
896 This will produce segments like this:
897 @file{segment_20170102194334_0003_00122200_0000003000000.ts}, @file{segment_20170102194334_0004_00120072_0000003000000.ts} etc.
900 Write segment data to filename.tmp and rename to filename only once the segment is complete. A webserver
901 serving up segments can be configured to reject requests to *.tmp to prevent access to in-progress segments
902 before they have been added to the m3u8 playlist. This flag also affects how m3u8 playlist files are created.
903 If this flag is set, all playlist files will written into temporary file and renamed after they are complete, similarly as segments are handled.
904 But playlists with @code{file} protocol and with type (@code{hls_playlist_type}) other than @code{vod}
905 are always written into temporary file regardles of this flag. Master playlist files (@code{master_pl_name}), if any, with @code{file} protocol,
906 are always written into temporary file regardles of this flag if @code{master_pl_publish_rate} value is other than zero.
910 @item hls_playlist_type event
911 Emit @code{#EXT-X-PLAYLIST-TYPE:EVENT} in the m3u8 header. Forces
912 @option{hls_list_size} to 0; the playlist can only be appended to.
914 @item hls_playlist_type vod
915 Emit @code{#EXT-X-PLAYLIST-TYPE:VOD} in the m3u8 header. Forces
916 @option{hls_list_size} to 0; the playlist must not change.
919 Use the given HTTP method to create the hls files.
921 ffmpeg -re -i in.ts -f hls -method PUT http://example.com/live/out.m3u8
923 This example will upload all the mpegts segment files to the HTTP
924 server using the HTTP PUT method, and update the m3u8 files every
925 @code{refresh} times using the same method.
926 Note that the HTTP server must support the given method for uploading
929 @item http_user_agent
930 Override User-Agent field in HTTP header. Applicable only for HTTP output.
933 Map string which specifies how to group the audio, video and subtitle streams
934 into different variant streams. The variant stream groups are separated
936 Expected string format is like this "a:0,v:0 a:1,v:1 ....". Here a:, v:, s: are
937 the keys to specify audio, video and subtitle streams respectively.
938 Allowed values are 0 to 9 (limited just based on practical usage).
940 When there are two or more variant streams, the output filename pattern must
941 contain the string "%v", this string specifies the position of variant stream
942 index in the output media playlist filenames. The string "%v" may be present in
943 the filename or in the last directory name containing the file. If the string is
944 present in the directory name, then sub-directories are created after expanding
945 the directory name pattern. This enables creation of variant streams in
949 ffmpeg -re -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k -b:a:1 32k \
950 -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" \
951 http://example.com/live/out_%v.m3u8
953 This example creates two hls variant streams. The first variant stream will
954 contain video stream of bitrate 1000k and audio stream of bitrate 64k and the
955 second variant stream will contain video stream of bitrate 256k and audio
956 stream of bitrate 32k. Here, two media playlist with file names out_0.m3u8 and
957 out_1.m3u8 will be created. If you want something meaningful text instead of indexes
958 in result names, you may specify names for each or some of the variants
959 as in the following example.
963 ffmpeg -re -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k -b:a:1 32k \
964 -map 0:v -map 0:a -map 0:v -map 0:a -f hls -var_stream_map "v:0,a:0,name:my_hd v:1,a:1,name:my_sd" \
965 http://example.com/live/out_%v.m3u8
968 This example creates two hls variant streams as in the previous one.
969 But here, the two media playlist with file names out_my_hd.m3u8 and
970 out_my_sd.m3u8 will be created.
973 ffmpeg -re -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k \
974 -map 0:v -map 0:a -map 0:v -f hls -var_stream_map "v:0 a:0 v:1" \
975 http://example.com/live/out_%v.m3u8
977 This example creates three hls variant streams. The first variant stream will
978 be a video only stream with video bitrate 1000k, the second variant stream will
979 be an audio only stream with bitrate 64k and the third variant stream will be a
980 video only stream with bitrate 256k. Here, three media playlist with file names
981 out_0.m3u8, out_1.m3u8 and out_2.m3u8 will be created.
983 ffmpeg -re -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k -b:a:1 32k \
984 -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" \
985 http://example.com/live/vs_%v/out.m3u8
987 This example creates the variant streams in subdirectories. Here, the first
988 media playlist is created at @file{http://example.com/live/vs_0/out.m3u8} and
989 the second one at @file{http://example.com/live/vs_1/out.m3u8}.
991 ffmpeg -re -i in.ts -b:a:0 32k -b:a:1 64k -b:v:0 1000k -b:v:1 3000k \
992 -map 0:a -map 0:a -map 0:v -map 0:v -f hls \
993 -var_stream_map "a:0,agroup:aud_low a:1,agroup:aud_high v:0,agroup:aud_low v:1,agroup:aud_high" \
994 -master_pl_name master.m3u8 \
995 http://example.com/live/out_%v.m3u8
997 This example creates two audio only and two video only variant streams. In
998 addition to the #EXT-X-STREAM-INF tag for each variant stream in the master
999 playlist, #EXT-X-MEDIA tag is also added for the two audio only variant streams
1000 and they are mapped to the two video only variant streams with audio group names
1001 'aud_low' and 'aud_high'.
1003 By default, a single hls variant containing all the encoded streams is created.
1006 ffmpeg -re -i in.ts -b:a:0 32k -b:a:1 64k -b:v:0 1000k \
1007 -map 0:a -map 0:a -map 0:v -f hls \
1008 -var_stream_map "a:0,agroup:aud_low,default:yes a:1,agroup:aud_low v:0,agroup:aud_low" \
1009 -master_pl_name master.m3u8 \
1010 http://example.com/live/out_%v.m3u8
1012 This example creates two audio only and one video only variant streams. In
1013 addition to the #EXT-X-STREAM-INF tag for each variant stream in the master
1014 playlist, #EXT-X-MEDIA tag is also added for the two audio only variant streams
1015 and they are mapped to the one video only variant streams with audio group name
1016 'aud_low', and the audio group have default stat is NO or YES.
1018 By default, a single hls variant containing all the encoded streams is created.
1021 ffmpeg -re -i in.ts -b:a:0 32k -b:a:1 64k -b:v:0 1000k \
1022 -map 0:a -map 0:a -map 0:v -f hls \
1023 -var_stream_map "a:0,agroup:aud_low,default:yes,language:ENG a:1,agroup:aud_low,language:CHN v:0,agroup:aud_low" \
1024 -master_pl_name master.m3u8 \
1025 http://example.com/live/out_%v.m3u8
1027 This example creates two audio only and one video only variant streams. In
1028 addition to the #EXT-X-STREAM-INF tag for each variant stream in the master
1029 playlist, #EXT-X-MEDIA tag is also added for the two audio only variant streams
1030 and they are mapped to the one video only variant streams with audio group name
1031 'aud_low', and the audio group have default stat is NO or YES, and one audio
1032 have and language is named ENG, the other audio language is named CHN.
1034 By default, a single hls variant containing all the encoded streams is created.
1037 Map string which specifies different closed captions groups and their
1038 attributes. The closed captions stream groups are separated by space.
1039 Expected string format is like this
1040 "ccgroup:<group name>,instreamid:<INSTREAM-ID>,language:<language code> ....".
1041 'ccgroup' and 'instreamid' are mandatory attributes. 'language' is an optional
1043 The closed captions groups configured using this option are mapped to different
1044 variant streams by providing the same 'ccgroup' name in the
1045 @code{var_stream_map} string. If @code{var_stream_map} is not set, then the
1046 first available ccgroup in @code{cc_stream_map} is mapped to the output variant
1047 stream. The examples for these two use cases are given below.
1050 ffmpeg -re -i in.ts -b:v 1000k -b:a 64k -a53cc 1 -f hls \
1051 -cc_stream_map "ccgroup:cc,instreamid:CC1,language:en" \
1052 -master_pl_name master.m3u8 \
1053 http://example.com/live/out.m3u8
1055 This example adds @code{#EXT-X-MEDIA} tag with @code{TYPE=CLOSED-CAPTIONS} in
1056 the master playlist with group name 'cc', language 'en' (english) and
1057 INSTREAM-ID 'CC1'. Also, it adds @code{CLOSED-CAPTIONS} attribute with group
1058 name 'cc' for the output variant stream.
1060 ffmpeg -re -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k -b:a:1 32k \
1061 -a53cc:0 1 -a53cc:1 1\
1062 -map 0:v -map 0:a -map 0:v -map 0:a -f hls \
1063 -cc_stream_map "ccgroup:cc,instreamid:CC1,language:en ccgroup:cc,instreamid:CC2,language:sp" \
1064 -var_stream_map "v:0,a:0,ccgroup:cc v:1,a:1,ccgroup:cc" \
1065 -master_pl_name master.m3u8 \
1066 http://example.com/live/out_%v.m3u8
1068 This example adds two @code{#EXT-X-MEDIA} tags with @code{TYPE=CLOSED-CAPTIONS} in
1069 the master playlist for the INSTREAM-IDs 'CC1' and 'CC2'. Also, it adds
1070 @code{CLOSED-CAPTIONS} attribute with group name 'cc' for the two output variant
1073 @item master_pl_name
1074 Create HLS master playlist with the given name.
1077 ffmpeg -re -i in.ts -f hls -master_pl_name master.m3u8 http://example.com/live/out.m3u8
1079 This example creates HLS master playlist with name master.m3u8 and it is
1080 published at http://example.com/live/
1082 @item master_pl_publish_rate
1083 Publish master play list repeatedly every after specified number of segment intervals.
1086 ffmpeg -re -i in.ts -f hls -master_pl_name master.m3u8 \
1087 -hls_time 2 -master_pl_publish_rate 30 http://example.com/live/out.m3u8
1090 This example creates HLS master playlist with name master.m3u8 and keep
1091 publishing it repeatedly every after 30 segments i.e. every after 60s.
1093 @item http_persistent
1094 Use persistent HTTP connections. Applicable only for HTTP output.
1097 Set timeout for socket I/O operations. Applicable only for HTTP output.
1099 @item -ignore_io_errors
1100 Ignore IO errors during open, write and delete. Useful for long-duration runs with network output.
1103 Set custom HTTP headers, can override built in default headers. Applicable only for HTTP output.
1112 Microsoft's icon file format (ICO) has some strict limitations that should be noted:
1116 Size cannot exceed 256 pixels in any dimension
1119 Only BMP and PNG images can be stored
1122 If a BMP image is used, it must be one of the following pixel formats:
1124 BMP Bit Depth FFmpeg Pixel Format
1134 If a BMP image is used, it must use the BITMAPINFOHEADER DIB header
1137 If a PNG image is used, it must use the rgba pixel format
1145 The image file muxer writes video frames to image files.
1147 The output filenames are specified by a pattern, which can be used to
1148 produce sequentially numbered series of files.
1149 The pattern may contain the string "%d" or "%0@var{N}d", this string
1150 specifies the position of the characters representing a numbering in
1151 the filenames. If the form "%0@var{N}d" is used, the string
1152 representing the number in each filename is 0-padded to @var{N}
1153 digits. The literal character '%' can be specified in the pattern with
1156 If the pattern contains "%d" or "%0@var{N}d", the first filename of
1157 the file list specified will contain the number 1, all the following
1158 numbers will be sequential.
1160 The pattern may contain a suffix which is used to automatically
1161 determine the format of the image files to write.
1163 For example the pattern "img-%03d.bmp" will specify a sequence of
1164 filenames of the form @file{img-001.bmp}, @file{img-002.bmp}, ...,
1165 @file{img-010.bmp}, etc.
1166 The pattern "img%%-%d.jpg" will specify a sequence of filenames of the
1167 form @file{img%-1.jpg}, @file{img%-2.jpg}, ..., @file{img%-10.jpg},
1170 @subsection Examples
1172 The following example shows how to use @command{ffmpeg} for creating a
1173 sequence of files @file{img-001.jpeg}, @file{img-002.jpeg}, ...,
1174 taking one image every second from the input video:
1176 ffmpeg -i in.avi -vsync cfr -r 1 -f image2 'img-%03d.jpeg'
1179 Note that with @command{ffmpeg}, if the format is not specified with the
1180 @code{-f} option and the output filename specifies an image file
1181 format, the image2 muxer is automatically selected, so the previous
1182 command can be written as:
1184 ffmpeg -i in.avi -vsync cfr -r 1 'img-%03d.jpeg'
1187 Note also that the pattern must not necessarily contain "%d" or
1188 "%0@var{N}d", for example to create a single image file
1189 @file{img.jpeg} from the start of the input video you can employ the command:
1191 ffmpeg -i in.avi -f image2 -frames:v 1 img.jpeg
1194 The @option{strftime} option allows you to expand the filename with
1195 date and time information. Check the documentation of
1196 the @code{strftime()} function for the syntax.
1198 For example to generate image files from the @code{strftime()}
1199 "%Y-%m-%d_%H-%M-%S" pattern, the following @command{ffmpeg} command
1202 ffmpeg -f v4l2 -r 1 -i /dev/video0 -f image2 -strftime 1 "%Y-%m-%d_%H-%M-%S.jpg"
1205 You can set the file name with current frame's PTS:
1207 ffmpeg -f v4l2 -r 1 -i /dev/video0 -copyts -f image2 -frame_pts true %d.jpg"
1214 If set to 1, expand the filename with pts from pkt->pts.
1218 Start the sequence from the specified number. Default value is 1.
1221 If set to 1, the filename will always be interpreted as just a
1222 filename, not a pattern, and the corresponding file will be continuously
1223 overwritten with new images. Default value is 0.
1226 If set to 1, expand the filename with date and time information from
1227 @code{strftime()}. Default value is 0.
1230 The image muxer supports the .Y.U.V image file format. This format is
1231 special in that that each image frame consists of three files, for
1232 each of the YUV420P components. To read or write this image file format,
1233 specify the name of the '.Y' file. The muxer will automatically open the
1234 '.U' and '.V' files as required.
1238 Matroska container muxer.
1240 This muxer implements the matroska and webm container specs.
1242 @subsection Metadata
1244 The recognized metadata settings in this muxer are:
1248 Set title name provided to a single track.
1251 Specify the language of the track in the Matroska languages form.
1253 The language can be either the 3 letters bibliographic ISO-639-2 (ISO
1254 639-2/B) form (like "fre" for French), or a language code mixed with a
1255 country code for specialities in languages (like "fre-ca" for Canadian
1259 Set stereo 3D video layout of two views in a single video track.
1261 The following values are recognized:
1266 Both views are arranged side by side, Left-eye view is on the left
1268 Both views are arranged in top-bottom orientation, Left-eye view is at bottom
1270 Both views are arranged in top-bottom orientation, Left-eye view is on top
1271 @item checkerboard_rl
1272 Each view is arranged in a checkerboard interleaved pattern, Left-eye view being first
1273 @item checkerboard_lr
1274 Each view is arranged in a checkerboard interleaved pattern, Right-eye view being first
1275 @item row_interleaved_rl
1276 Each view is constituted by a row based interleaving, Right-eye view is first row
1277 @item row_interleaved_lr
1278 Each view is constituted by a row based interleaving, Left-eye view is first row
1279 @item col_interleaved_rl
1280 Both views are arranged in a column based interleaving manner, Right-eye view is first column
1281 @item col_interleaved_lr
1282 Both views are arranged in a column based interleaving manner, Left-eye view is first column
1283 @item anaglyph_cyan_red
1284 All frames are in anaglyph format viewable through red-cyan filters
1286 Both views are arranged side by side, Right-eye view is on the left
1287 @item anaglyph_green_magenta
1288 All frames are in anaglyph format viewable through green-magenta filters
1290 Both eyes laced in one Block, Left-eye view is first
1292 Both eyes laced in one Block, Right-eye view is first
1296 For example a 3D WebM clip can be created using the following command line:
1298 ffmpeg -i sample_left_right_clip.mpg -an -c:v libvpx -metadata stereo_mode=left_right -y stereo_clip.webm
1303 This muxer supports the following options:
1306 @item reserve_index_space
1307 By default, this muxer writes the index for seeking (called cues in Matroska
1308 terms) at the end of the file, because it cannot know in advance how much space
1309 to leave for the index at the beginning of the file. However for some use cases
1310 -- e.g. streaming where seeking is possible but slow -- it is useful to put the
1311 index at the beginning of the file.
1313 If this option is set to a non-zero value, the muxer will reserve a given amount
1314 of space in the file header and then try to write the cues there when the muxing
1315 finishes. If the available space does not suffice, muxing will fail. A safe size
1316 for most use cases should be about 50kB per hour of video.
1318 Note that cues are only written if the output is seekable and this option will
1319 have no effect if it is not.
1327 This is a variant of the @ref{hash} muxer. Unlike that muxer, it
1328 defaults to using the MD5 hash function.
1330 @subsection Examples
1332 To compute the MD5 hash of the input converted to raw
1333 audio and video, and store it in the file @file{out.md5}:
1335 ffmpeg -i INPUT -f md5 out.md5
1338 You can print the MD5 to stdout with the command:
1340 ffmpeg -i INPUT -f md5 -
1343 See also the @ref{hash} and @ref{framemd5} muxers.
1345 @section mov, mp4, ismv
1347 MOV/MP4/ISMV (Smooth Streaming) muxer.
1349 The mov/mp4/ismv muxer supports fragmentation. Normally, a MOV/MP4
1350 file has all the metadata about all packets stored in one location
1351 (written at the end of the file, it can be moved to the start for
1352 better playback by adding @var{faststart} to the @var{movflags}, or
1353 using the @command{qt-faststart} tool). A fragmented
1354 file consists of a number of fragments, where packets and metadata
1355 about these packets are stored together. Writing a fragmented
1356 file has the advantage that the file is decodable even if the
1357 writing is interrupted (while a normal MOV/MP4 is undecodable if
1358 it is not properly finished), and it requires less memory when writing
1359 very long files (since writing normal MOV/MP4 files stores info about
1360 every single packet in memory until the file is closed). The downside
1361 is that it is less compatible with other applications.
1365 Fragmentation is enabled by setting one of the AVOptions that define
1366 how to cut the file into fragments:
1369 @item -moov_size @var{bytes}
1370 Reserves space for the moov atom at the beginning of the file instead of placing the
1371 moov atom at the end. If the space reserved is insufficient, muxing will fail.
1372 @item -movflags frag_keyframe
1373 Start a new fragment at each video keyframe.
1374 @item -frag_duration @var{duration}
1375 Create fragments that are @var{duration} microseconds long.
1376 @item -frag_size @var{size}
1377 Create fragments that contain up to @var{size} bytes of payload data.
1378 @item -movflags frag_custom
1379 Allow the caller to manually choose when to cut fragments, by
1380 calling @code{av_write_frame(ctx, NULL)} to write a fragment with
1381 the packets written so far. (This is only useful with other
1382 applications integrating libavformat, not from @command{ffmpeg}.)
1383 @item -min_frag_duration @var{duration}
1384 Don't create fragments that are shorter than @var{duration} microseconds long.
1387 If more than one condition is specified, fragments are cut when
1388 one of the specified conditions is fulfilled. The exception to this is
1389 @code{-min_frag_duration}, which has to be fulfilled for any of the other
1390 conditions to apply.
1392 Additionally, the way the output file is written can be adjusted
1393 through a few other options:
1396 @item -movflags empty_moov
1397 Write an initial moov atom directly at the start of the file, without
1398 describing any samples in it. Generally, an mdat/moov pair is written
1399 at the start of the file, as a normal MOV/MP4 file, containing only
1400 a short portion of the file. With this option set, there is no initial
1401 mdat atom, and the moov atom only describes the tracks but has
1404 This option is implicitly set when writing ismv (Smooth Streaming) files.
1405 @item -movflags separate_moof
1406 Write a separate moof (movie fragment) atom for each track. Normally,
1407 packets for all tracks are written in a moof atom (which is slightly
1408 more efficient), but with this option set, the muxer writes one moof/mdat
1409 pair for each track, making it easier to separate tracks.
1411 This option is implicitly set when writing ismv (Smooth Streaming) files.
1412 @item -movflags skip_sidx
1413 Skip writing of sidx atom. When bitrate overhead due to sidx atom is high,
1414 this option could be used for cases where sidx atom is not mandatory.
1415 When global_sidx flag is enabled, this option will be ignored.
1416 @item -movflags faststart
1417 Run a second pass moving the index (moov atom) to the beginning of the file.
1418 This operation can take a while, and will not work in various situations such
1419 as fragmented output, thus it is not enabled by default.
1420 @item -movflags rtphint
1421 Add RTP hinting tracks to the output file.
1422 @item -movflags disable_chpl
1423 Disable Nero chapter markers (chpl atom). Normally, both Nero chapters
1424 and a QuickTime chapter track are written to the file. With this option
1425 set, only the QuickTime chapter track will be written. Nero chapters can
1426 cause failures when the file is reprocessed with certain tagging programs, like
1427 mp3Tag 2.61a and iTunes 11.3, most likely other versions are affected as well.
1428 @item -movflags omit_tfhd_offset
1429 Do not write any absolute base_data_offset in tfhd atoms. This avoids
1430 tying fragments to absolute byte positions in the file/streams.
1431 @item -movflags default_base_moof
1432 Similarly to the omit_tfhd_offset, this flag avoids writing the
1433 absolute base_data_offset field in tfhd atoms, but does so by using
1434 the new default-base-is-moof flag instead. This flag is new from
1435 14496-12:2012. This may make the fragments easier to parse in certain
1436 circumstances (avoiding basing track fragment location calculations
1437 on the implicit end of the previous track fragment).
1439 Specify @code{on} to force writing a timecode track, @code{off} to disable it
1440 and @code{auto} to write a timecode track only for mov and mp4 output (default).
1441 @item -movflags negative_cts_offsets
1442 Enables utilization of version 1 of the CTTS box, in which the CTS offsets can
1443 be negative. This enables the initial sample to have DTS/CTS of zero, and
1444 reduces the need for edit lists for some cases such as video tracks with
1445 B-frames. Additionally, eases conformance with the DASH-IF interoperability
1448 This option is implicitly set when writing ismv (Smooth Streaming) files.
1450 Write producer time reference box (PRFT) with a specified time source for the
1451 NTP field in the PRFT box. Set value as @samp{wallclock} to specify timesource
1452 as wallclock time and @samp{pts} to specify timesource as input packets' PTS
1455 Setting value to @samp{pts} is applicable only for a live encoding use case,
1456 where PTS values are set as as wallclock time at the source. For example, an
1457 encoding use case with decklink capture source where @option{video_pts} and
1458 @option{audio_pts} are set to @samp{abs_wallclock}.
1463 Smooth Streaming content can be pushed in real time to a publishing
1464 point on IIS with this muxer. Example:
1466 ffmpeg -re @var{<normal input/transcoding options>} -movflags isml+frag_keyframe -f ismv http://server/publishingpoint.isml/Streams(Encoder1)
1469 @subsection Audible AAX
1471 Audible AAX files are encrypted M4B files, and they can be decrypted by specifying a 4 byte activation secret.
1473 ffmpeg -activation_bytes 1CEB00DA -i test.aax -vn -c:a copy output.mp4
1478 The MP3 muxer writes a raw MP3 stream with the following optional features:
1481 An ID3v2 metadata header at the beginning (enabled by default). Versions 2.3 and
1482 2.4 are supported, the @code{id3v2_version} private option controls which one is
1483 used (3 or 4). Setting @code{id3v2_version} to 0 disables the ID3v2 header
1486 The muxer supports writing attached pictures (APIC frames) to the ID3v2 header.
1487 The pictures are supplied to the muxer in form of a video stream with a single
1488 packet. There can be any number of those streams, each will correspond to a
1489 single APIC frame. The stream metadata tags @var{title} and @var{comment} map
1490 to APIC @var{description} and @var{picture type} respectively. See
1491 @url{http://id3.org/id3v2.4.0-frames} for allowed picture types.
1493 Note that the APIC frames must be written at the beginning, so the muxer will
1494 buffer the audio frames until it gets all the pictures. It is therefore advised
1495 to provide the pictures as soon as possible to avoid excessive buffering.
1498 A Xing/LAME frame right after the ID3v2 header (if present). It is enabled by
1499 default, but will be written only if the output is seekable. The
1500 @code{write_xing} private option can be used to disable it. The frame contains
1501 various information that may be useful to the decoder, like the audio duration
1505 A legacy ID3v1 tag at the end of the file (disabled by default). It may be
1506 enabled with the @code{write_id3v1} private option, but as its capabilities are
1507 very limited, its usage is not recommended.
1512 Write an mp3 with an ID3v2.3 header and an ID3v1 footer:
1514 ffmpeg -i INPUT -id3v2_version 3 -write_id3v1 1 out.mp3
1517 To attach a picture to an mp3 file select both the audio and the picture stream
1520 ffmpeg -i input.mp3 -i cover.png -c copy -map 0 -map 1
1521 -metadata:s:v title="Album cover" -metadata:s:v comment="Cover (Front)" out.mp3
1524 Write a "clean" MP3 without any extra features:
1526 ffmpeg -i input.wav -write_xing 0 -id3v2_version 0 out.mp3
1531 MPEG transport stream muxer.
1533 This muxer implements ISO 13818-1 and part of ETSI EN 300 468.
1535 The recognized metadata settings in mpegts muxer are @code{service_provider}
1536 and @code{service_name}. If they are not set the default for
1537 @code{service_provider} is @samp{FFmpeg} and the default for
1538 @code{service_name} is @samp{Service01}.
1542 The muxer options are:
1545 @item mpegts_transport_stream_id @var{integer}
1546 Set the @samp{transport_stream_id}. This identifies a transponder in DVB.
1547 Default is @code{0x0001}.
1549 @item mpegts_original_network_id @var{integer}
1550 Set the @samp{original_network_id}. This is unique identifier of a
1551 network in DVB. Its main use is in the unique identification of a service
1552 through the path @samp{Original_Network_ID, Transport_Stream_ID}. Default
1555 @item mpegts_service_id @var{integer}
1556 Set the @samp{service_id}, also known as program in DVB. Default is
1559 @item mpegts_service_type @var{integer}
1560 Set the program @samp{service_type}. Default is @code{digital_tv}.
1561 Accepts the following options:
1564 Any hexadecimal value between @code{0x01} and @code{0xff} as defined in
1569 Digital Radio service.
1572 @item advanced_codec_digital_radio
1573 Advanced Codec Digital Radio service.
1574 @item mpeg2_digital_hdtv
1575 MPEG2 Digital HDTV service.
1576 @item advanced_codec_digital_sdtv
1577 Advanced Codec Digital SDTV service.
1578 @item advanced_codec_digital_hdtv
1579 Advanced Codec Digital HDTV service.
1582 @item mpegts_pmt_start_pid @var{integer}
1583 Set the first PID for PMT. Default is @code{0x1000}. Max is @code{0x1f00}.
1585 @item mpegts_start_pid @var{integer}
1586 Set the first PID for data packets. Default is @code{0x0100}. Max is
1589 @item mpegts_m2ts_mode @var{boolean}
1590 Enable m2ts mode if set to @code{1}. Default value is @code{-1} which
1593 @item muxrate @var{integer}
1594 Set a constant muxrate. Default is VBR.
1596 @item pes_payload_size @var{integer}
1597 Set minimum PES packet payload in bytes. Default is @code{2930}.
1599 @item mpegts_flags @var{flags}
1600 Set mpegts flags. Accepts the following options:
1602 @item resend_headers
1603 Reemit PAT/PMT before writing the next packet.
1605 Use LATM packetization for AAC.
1606 @item pat_pmt_at_frames
1607 Reemit PAT and PMT at each video frame.
1609 Conform to System B (DVB) instead of System A (ATSC).
1610 @item initial_discontinuity
1611 Mark the initial packet of each stream as discontinuity.
1614 @item mpegts_copyts @var{boolean}
1615 Preserve original timestamps, if value is set to @code{1}. Default value
1616 is @code{-1}, which results in shifting timestamps so that they start from 0.
1618 @item omit_video_pes_length @var{boolean}
1619 Omit the PES packet length for video packets. Default is @code{1} (true).
1621 @item pcr_period @var{integer}
1622 Override the default PCR retransmission time in milliseconds. Ignored if
1623 variable muxrate is selected. Default is @code{20}.
1625 @item pat_period @var{double}
1626 Maximum time in seconds between PAT/PMT tables.
1628 @item sdt_period @var{double}
1629 Maximum time in seconds between SDT tables.
1631 @item tables_version @var{integer}
1632 Set PAT, PMT and SDT version (default @code{0}, valid values are from 0 to 31, inclusively).
1633 This option allows updating stream structure so that standard consumer may
1634 detect the change. To do so, reopen output @code{AVFormatContext} (in case of API
1635 usage) or restart @command{ffmpeg} instance, cyclically changing
1636 @option{tables_version} value:
1639 ffmpeg -i source1.ts -codec copy -f mpegts -tables_version 0 udp://1.1.1.1:1111
1640 ffmpeg -i source2.ts -codec copy -f mpegts -tables_version 1 udp://1.1.1.1:1111
1642 ffmpeg -i source3.ts -codec copy -f mpegts -tables_version 31 udp://1.1.1.1:1111
1643 ffmpeg -i source1.ts -codec copy -f mpegts -tables_version 0 udp://1.1.1.1:1111
1644 ffmpeg -i source2.ts -codec copy -f mpegts -tables_version 1 udp://1.1.1.1:1111
1652 ffmpeg -i file.mpg -c copy \
1653 -mpegts_original_network_id 0x1122 \
1654 -mpegts_transport_stream_id 0x3344 \
1655 -mpegts_service_id 0x5566 \
1656 -mpegts_pmt_start_pid 0x1500 \
1657 -mpegts_start_pid 0x150 \
1658 -metadata service_provider="Some provider" \
1659 -metadata service_name="Some Channel" \
1663 @section mxf, mxf_d10, mxf_opatom
1669 The muxer options are:
1672 @item store_user_comments @var{bool}
1673 Set if user comments should be stored if available or never.
1674 IRT D-10 does not allow user comments. The default is thus to write them for
1675 mxf and mxf_opatom but not for mxf_d10
1682 This muxer does not generate any output file, it is mainly useful for
1683 testing or benchmarking purposes.
1685 For example to benchmark decoding with @command{ffmpeg} you can use the
1688 ffmpeg -benchmark -i INPUT -f null out.null
1691 Note that the above command does not read or write the @file{out.null}
1692 file, but specifying the output file is required by the @command{ffmpeg}
1695 Alternatively you can write the command as:
1697 ffmpeg -benchmark -i INPUT -f null -
1703 @item -syncpoints @var{flags}
1704 Change the syncpoint usage in nut:
1706 @item @var{default} use the normal low-overhead seeking aids.
1707 @item @var{none} do not use the syncpoints at all, reducing the overhead but making the stream non-seekable;
1708 Use of this option is not recommended, as the resulting files are very damage
1709 sensitive and seeking is not possible. Also in general the overhead from
1710 syncpoints is negligible. Note, -@code{write_index} 0 can be used to disable
1711 all growing data tables, allowing to mux endless streams with limited memory
1712 and without these disadvantages.
1713 @item @var{timestamped} extend the syncpoint with a wallclock field.
1715 The @var{none} and @var{timestamped} flags are experimental.
1716 @item -write_index @var{bool}
1717 Write index at the end, the default is to write an index.
1721 ffmpeg -i INPUT -f_strict experimental -syncpoints none - | processor
1726 Ogg container muxer.
1729 @item -page_duration @var{duration}
1730 Preferred page duration, in microseconds. The muxer will attempt to create
1731 pages that are approximately @var{duration} microseconds long. This allows the
1732 user to compromise between seek granularity and container overhead. The default
1733 is 1 second. A value of 0 will fill all segments, making pages as large as
1734 possible. A value of 1 will effectively use 1 packet-per-page in most
1735 situations, giving a small seek granularity at the cost of additional container
1737 @item -serial_offset @var{value}
1738 Serial value from which to set the streams serial number.
1739 Setting it to different and sufficiently large values ensures that the produced
1740 ogg files can be safely chained.
1745 @section segment, stream_segment, ssegment
1747 Basic stream segmenter.
1749 This muxer outputs streams to a number of separate files of nearly
1750 fixed duration. Output filename pattern can be set in a fashion
1751 similar to @ref{image2}, or by using a @code{strftime} template if
1752 the @option{strftime} option is enabled.
1754 @code{stream_segment} is a variant of the muxer used to write to
1755 streaming output formats, i.e. which do not require global headers,
1756 and is recommended for outputting e.g. to MPEG transport stream segments.
1757 @code{ssegment} is a shorter alias for @code{stream_segment}.
1759 Every segment starts with a keyframe of the selected reference stream,
1760 which is set through the @option{reference_stream} option.
1762 Note that if you want accurate splitting for a video file, you need to
1763 make the input key frames correspond to the exact splitting times
1764 expected by the segmenter, or the segment muxer will start the new
1765 segment with the key frame found next after the specified start
1768 The segment muxer works best with a single constant frame rate video.
1770 Optionally it can generate a list of the created segments, by setting
1771 the option @var{segment_list}. The list type is specified by the
1772 @var{segment_list_type} option. The entry filenames in the segment
1773 list are set by default to the basename of the corresponding segment
1776 See also the @ref{hls} muxer, which provides a more specific
1777 implementation for HLS segmentation.
1781 The segment muxer supports the following options:
1784 @item increment_tc @var{1|0}
1785 if set to @code{1}, increment timecode between each segment
1786 If this is selected, the input need to have
1787 a timecode in the first video stream. Default value is
1790 @item reference_stream @var{specifier}
1791 Set the reference stream, as specified by the string @var{specifier}.
1792 If @var{specifier} is set to @code{auto}, the reference is chosen
1793 automatically. Otherwise it must be a stream specifier (see the ``Stream
1794 specifiers'' chapter in the ffmpeg manual) which specifies the
1795 reference stream. The default value is @code{auto}.
1797 @item segment_format @var{format}
1798 Override the inner container format, by default it is guessed by the filename
1801 @item segment_format_options @var{options_list}
1802 Set output format options using a :-separated list of key=value
1803 parameters. Values containing the @code{:} special character must be
1806 @item segment_list @var{name}
1807 Generate also a listfile named @var{name}. If not specified no
1808 listfile is generated.
1810 @item segment_list_flags @var{flags}
1811 Set flags affecting the segment list generation.
1813 It currently supports the following flags:
1816 Allow caching (only affects M3U8 list files).
1819 Allow live-friendly file generation.
1822 @item segment_list_size @var{size}
1823 Update the list file so that it contains at most @var{size}
1824 segments. If 0 the list file will contain all the segments. Default
1827 @item segment_list_entry_prefix @var{prefix}
1828 Prepend @var{prefix} to each entry. Useful to generate absolute paths.
1829 By default no prefix is applied.
1831 @item segment_list_type @var{type}
1832 Select the listing format.
1834 The following values are recognized:
1837 Generate a flat list for the created segments, one segment per line.
1840 Generate a list for the created segments, one segment per line,
1841 each line matching the format (comma-separated values):
1843 @var{segment_filename},@var{segment_start_time},@var{segment_end_time}
1846 @var{segment_filename} is the name of the output file generated by the
1847 muxer according to the provided pattern. CSV escaping (according to
1848 RFC4180) is applied if required.
1850 @var{segment_start_time} and @var{segment_end_time} specify
1851 the segment start and end time expressed in seconds.
1853 A list file with the suffix @code{".csv"} or @code{".ext"} will
1854 auto-select this format.
1856 @samp{ext} is deprecated in favor or @samp{csv}.
1859 Generate an ffconcat file for the created segments. The resulting file
1860 can be read using the FFmpeg @ref{concat} demuxer.
1862 A list file with the suffix @code{".ffcat"} or @code{".ffconcat"} will
1863 auto-select this format.
1866 Generate an extended M3U8 file, version 3, compliant with
1867 @url{http://tools.ietf.org/id/draft-pantos-http-live-streaming}.
1869 A list file with the suffix @code{".m3u8"} will auto-select this format.
1872 If not specified the type is guessed from the list file name suffix.
1874 @item segment_time @var{time}
1875 Set segment duration to @var{time}, the value must be a duration
1876 specification. Default value is "2". See also the
1877 @option{segment_times} option.
1879 Note that splitting may not be accurate, unless you force the
1880 reference stream key-frames at the given time. See the introductory
1881 notice and the examples below.
1883 @item segment_atclocktime @var{1|0}
1884 If set to "1" split at regular clock time intervals starting from 00:00
1885 o'clock. The @var{time} value specified in @option{segment_time} is
1886 used for setting the length of the splitting interval.
1888 For example with @option{segment_time} set to "900" this makes it possible
1889 to create files at 12:00 o'clock, 12:15, 12:30, etc.
1891 Default value is "0".
1893 @item segment_clocktime_offset @var{duration}
1894 Delay the segment splitting times with the specified duration when using
1895 @option{segment_atclocktime}.
1897 For example with @option{segment_time} set to "900" and
1898 @option{segment_clocktime_offset} set to "300" this makes it possible to
1899 create files at 12:05, 12:20, 12:35, etc.
1901 Default value is "0".
1903 @item segment_clocktime_wrap_duration @var{duration}
1904 Force the segmenter to only start a new segment if a packet reaches the muxer
1905 within the specified duration after the segmenting clock time. This way you
1906 can make the segmenter more resilient to backward local time jumps, such as
1907 leap seconds or transition to standard time from daylight savings time.
1909 Default is the maximum possible duration which means starting a new segment
1910 regardless of the elapsed time since the last clock time.
1912 @item segment_time_delta @var{delta}
1913 Specify the accuracy time when selecting the start time for a
1914 segment, expressed as a duration specification. Default value is "0".
1916 When delta is specified a key-frame will start a new segment if its
1917 PTS satisfies the relation:
1919 PTS >= start_time - time_delta
1922 This option is useful when splitting video content, which is always
1923 split at GOP boundaries, in case a key frame is found just before the
1924 specified split time.
1926 In particular may be used in combination with the @file{ffmpeg} option
1927 @var{force_key_frames}. The key frame times specified by
1928 @var{force_key_frames} may not be set accurately because of rounding
1929 issues, with the consequence that a key frame time may result set just
1930 before the specified time. For constant frame rate videos a value of
1931 1/(2*@var{frame_rate}) should address the worst case mismatch between
1932 the specified time and the time set by @var{force_key_frames}.
1934 @item segment_times @var{times}
1935 Specify a list of split points. @var{times} contains a list of comma
1936 separated duration specifications, in increasing order. See also
1937 the @option{segment_time} option.
1939 @item segment_frames @var{frames}
1940 Specify a list of split video frame numbers. @var{frames} contains a
1941 list of comma separated integer numbers, in increasing order.
1943 This option specifies to start a new segment whenever a reference
1944 stream key frame is found and the sequential number (starting from 0)
1945 of the frame is greater or equal to the next value in the list.
1947 @item segment_wrap @var{limit}
1948 Wrap around segment index once it reaches @var{limit}.
1950 @item segment_start_number @var{number}
1951 Set the sequence number of the first segment. Defaults to @code{0}.
1953 @item strftime @var{1|0}
1954 Use the @code{strftime} function to define the name of the new
1955 segments to write. If this is selected, the output segment name must
1956 contain a @code{strftime} function template. Default value is
1959 @item break_non_keyframes @var{1|0}
1960 If enabled, allow segments to start on frames other than keyframes. This
1961 improves behavior on some players when the time between keyframes is
1962 inconsistent, but may make things worse on others, and can cause some oddities
1963 during seeking. Defaults to @code{0}.
1965 @item reset_timestamps @var{1|0}
1966 Reset timestamps at the beginning of each segment, so that each segment
1967 will start with near-zero timestamps. It is meant to ease the playback
1968 of the generated segments. May not work with some combinations of
1969 muxers/codecs. It is set to @code{0} by default.
1971 @item initial_offset @var{offset}
1972 Specify timestamp offset to apply to the output packet timestamps. The
1973 argument must be a time duration specification, and defaults to 0.
1975 @item write_empty_segments @var{1|0}
1976 If enabled, write an empty segment if there are no packets during the period a
1977 segment would usually span. Otherwise, the segment will be filled with the next
1978 packet written. Defaults to @code{0}.
1981 Make sure to require a closed GOP when encoding and to set the GOP
1982 size to fit your segment time constraint.
1984 @subsection Examples
1988 Remux the content of file @file{in.mkv} to a list of segments
1989 @file{out-000.nut}, @file{out-001.nut}, etc., and write the list of
1990 generated segments to @file{out.list}:
1992 ffmpeg -i in.mkv -codec hevc -flags +cgop -g 60 -map 0 -f segment -segment_list out.list out%03d.nut
1996 Segment input and set output format options for the output segments:
1998 ffmpeg -i in.mkv -f segment -segment_time 10 -segment_format_options movflags=+faststart out%03d.mp4
2002 Segment the input file according to the split points specified by the
2003 @var{segment_times} option:
2005 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
2009 Use the @command{ffmpeg} @option{force_key_frames}
2010 option to force key frames in the input at the specified location, together
2011 with the segment option @option{segment_time_delta} to account for
2012 possible roundings operated when setting key frame times.
2014 ffmpeg -i in.mkv -force_key_frames 1,2,3,5,8,13,21 -codec:v mpeg4 -codec:a pcm_s16le -map 0 \
2015 -f segment -segment_list out.csv -segment_times 1,2,3,5,8,13,21 -segment_time_delta 0.05 out%03d.nut
2017 In order to force key frames on the input file, transcoding is
2021 Segment the input file by splitting the input file according to the
2022 frame numbers sequence specified with the @option{segment_frames} option:
2024 ffmpeg -i in.mkv -codec copy -map 0 -f segment -segment_list out.csv -segment_frames 100,200,300,500,800 out%03d.nut
2028 Convert the @file{in.mkv} to TS segments using the @code{libx264}
2029 and @code{aac} encoders:
2031 ffmpeg -i in.mkv -map 0 -codec:v libx264 -codec:a aac -f ssegment -segment_list out.list out%03d.ts
2035 Segment the input file, and create an M3U8 live playlist (can be used
2036 as live HLS source):
2038 ffmpeg -re -i in.mkv -codec copy -map 0 -f segment -segment_list playlist.m3u8 \
2039 -segment_list_flags +live -segment_time 10 out%03d.mkv
2043 @section smoothstreaming
2045 Smooth Streaming muxer generates a set of files (Manifest, chunks) suitable for serving with conventional web server.
2049 Specify the number of fragments kept in the manifest. Default 0 (keep all).
2051 @item extra_window_size
2052 Specify the number of fragments kept outside of the manifest before removing from disk. Default 5.
2054 @item lookahead_count
2055 Specify the number of lookahead fragments. Default 2.
2057 @item min_frag_duration
2058 Specify the minimum fragment duration (in microseconds). Default 5000000.
2060 @item remove_at_exit
2061 Specify whether to remove all fragments when finished. Default 0 (do not remove).
2068 The fifo pseudo-muxer allows the separation of encoding and muxing by using
2069 first-in-first-out queue and running the actual muxer in a separate thread. This
2070 is especially useful in combination with the @ref{tee} muxer and can be used to
2071 send data to several destinations with different reliability/writing speed/latency.
2073 API users should be aware that callback functions (interrupt_callback,
2074 io_open and io_close) used within its AVFormatContext must be thread-safe.
2076 The behavior of the fifo muxer if the queue fills up or if the output fails is
2082 output can be transparently restarted with configurable delay between retries
2083 based on real time or time of the processed stream.
2086 encoding can be blocked during temporary failure, or continue transparently
2087 dropping packets in case fifo queue fills up.
2094 Specify the format name. Useful if it cannot be guessed from the
2098 Specify size of the queue (number of packets). Default value is 60.
2101 Specify format options for the underlying muxer. Muxer options can be specified
2102 as a list of @var{key}=@var{value} pairs separated by ':'.
2104 @item drop_pkts_on_overflow @var{bool}
2105 If set to 1 (true), in case the fifo queue fills up, packets will be dropped
2106 rather than blocking the encoder. This makes it possible to continue streaming without
2107 delaying the input, at the cost of omitting part of the stream. By default
2108 this option is set to 0 (false), so in such cases the encoder will be blocked
2109 until the muxer processes some of the packets and none of them is lost.
2111 @item attempt_recovery @var{bool}
2112 If failure occurs, attempt to recover the output. This is especially useful
2113 when used with network output, since it makes it possible to restart streaming transparently.
2114 By default this option is set to 0 (false).
2116 @item max_recovery_attempts
2117 Sets maximum number of successive unsuccessful recovery attempts after which
2118 the output fails permanently. By default this option is set to 0 (unlimited).
2120 @item recovery_wait_time @var{duration}
2121 Waiting time before the next recovery attempt after previous unsuccessful
2122 recovery attempt. Default value is 5 seconds.
2124 @item recovery_wait_streamtime @var{bool}
2125 If set to 0 (false), the real time is used when waiting for the recovery
2126 attempt (i.e. the recovery will be attempted after at least
2127 recovery_wait_time seconds).
2128 If set to 1 (true), the time of the processed stream is taken into account
2129 instead (i.e. the recovery will be attempted after at least @var{recovery_wait_time}
2130 seconds of the stream is omitted).
2131 By default, this option is set to 0 (false).
2133 @item recover_any_error @var{bool}
2134 If set to 1 (true), recovery will be attempted regardless of type of the error
2135 causing the failure. By default this option is set to 0 (false) and in case of
2136 certain (usually permanent) errors the recovery is not attempted even when
2137 @var{attempt_recovery} is set to 1.
2139 @item restart_with_keyframe @var{bool}
2140 Specify whether to wait for the keyframe after recovering from
2141 queue overflow or failure. This option is set to 0 (false) by default.
2145 @subsection Examples
2150 Stream something to rtmp server, continue processing the stream at real-time
2151 rate even in case of temporary failure (network outage) and attempt to recover
2152 streaming every second indefinitely.
2154 ffmpeg -re -i ... -c:v libx264 -c:a aac -f fifo -fifo_format flv -map 0:v -map 0:a
2155 -drop_pkts_on_overflow 1 -attempt_recovery 1 -recovery_wait_time 1 rtmp://example.com/live/stream_name
2163 The tee muxer can be used to write the same data to several outputs, such as files or streams.
2164 It can be used, for example, to stream a video over a network and save it to disk at the same time.
2166 It is different from specifying several outputs to the @command{ffmpeg}
2167 command-line tool. With the tee muxer, the audio and video data will be encoded only once.
2168 With conventional multiple outputs, multiple encoding operations in parallel are initiated,
2169 which can be a very expensive process. The tee muxer is not useful when using the libavformat API
2170 directly because it is then possible to feed the same packets to several muxers directly.
2172 Since the tee muxer does not represent any particular output format, ffmpeg cannot auto-select
2173 output streams. So all streams intended for output must be specified using @code{-map}. See
2176 Some encoders may need different options depending on the output format;
2177 the auto-detection of this can not work with the tee muxer, so they need to be explicitly specified.
2178 The main example is the @option{global_header} flag.
2180 The slave outputs are specified in the file name given to the muxer,
2181 separated by '|'. If any of the slave name contains the '|' separator,
2182 leading or trailing spaces or any special character, those must be
2183 escaped (see @ref{quoting_and_escaping,,the "Quoting and escaping"
2184 section in the ffmpeg-utils(1) manual,ffmpeg-utils}).
2190 @item use_fifo @var{bool}
2191 If set to 1, slave outputs will be processed in separate threads using the @ref{fifo}
2192 muxer. This allows to compensate for different speed/latency/reliability of
2193 outputs and setup transparent recovery. By default this feature is turned off.
2196 Options to pass to fifo pseudo-muxer instances. See @ref{fifo}.
2200 Muxer options can be specified for each slave by prepending them as a list of
2201 @var{key}=@var{value} pairs separated by ':', between square brackets. If
2202 the options values contain a special character or the ':' separator, they
2203 must be escaped; note that this is a second level escaping.
2205 The following special options are also recognized:
2208 Specify the format name. Required if it cannot be guessed from the
2211 @item bsfs[/@var{spec}]
2212 Specify a list of bitstream filters to apply to the specified
2215 It is possible to specify to which streams a given bitstream filter
2216 applies, by appending a stream specifier to the option separated by
2217 @code{/}. @var{spec} must be a stream specifier (see @ref{Format
2218 stream specifiers}).
2220 If the stream specifier is not specified, the bitstream filters will be
2221 applied to all streams in the output. This will cause that output operation
2222 to fail if the output contains streams to which the bitstream filter cannot
2223 be applied e.g. @code{h264_mp4toannexb} being applied to an output containing an audio stream.
2225 Options for a bitstream filter must be specified in the form of @code{opt=value}.
2227 Several bitstream filters can be specified, separated by ",".
2229 @item use_fifo @var{bool}
2230 This allows to override tee muxer use_fifo option for individual slave muxer.
2233 This allows to override tee muxer fifo_options for individual slave muxer.
2237 Select the streams that should be mapped to the slave output,
2238 specified by a stream specifier. If not specified, this defaults to
2239 all the mapped streams. This will cause that output operation to fail
2240 if the output format does not accept all mapped streams.
2242 You may use multiple stream specifiers separated by commas (@code{,}) e.g.: @code{a:0,v}
2245 Specify behaviour on output failure. This can be set to either @code{abort} (which is
2246 default) or @code{ignore}. @code{abort} will cause whole process to fail in case of failure
2247 on this slave output. @code{ignore} will ignore failure on this output, so other outputs
2248 will continue without being affected.
2251 @subsection Examples
2255 Encode something and both archive it in a WebM file and stream it
2256 as MPEG-TS over UDP:
2258 ffmpeg -i ... -c:v libx264 -c:a mp2 -f tee -map 0:v -map 0:a
2259 "archive-20121107.mkv|[f=mpegts]udp://10.0.1.255:1234/"
2263 As above, but continue streaming even if output to local file fails
2264 (for example local drive fills up):
2266 ffmpeg -i ... -c:v libx264 -c:a mp2 -f tee -map 0:v -map 0:a
2267 "[onfail=ignore]archive-20121107.mkv|[f=mpegts]udp://10.0.1.255:1234/"
2271 Use @command{ffmpeg} to encode the input, and send the output
2272 to three different destinations. The @code{dump_extra} bitstream
2273 filter is used to add extradata information to all the output video
2274 keyframes packets, as requested by the MPEG-TS format. The select
2275 option is applied to @file{out.aac} in order to make it contain only
2278 ffmpeg -i ... -map 0 -flags +global_header -c:v libx264 -c:a aac
2279 -f tee "[bsfs/v=dump_extra=freq=keyframe]out.ts|[movflags=+faststart]out.mp4|[select=a]out.aac"
2283 As above, but select only stream @code{a:1} for the audio output. Note
2284 that a second level escaping must be performed, as ":" is a special
2285 character used to separate options.
2287 ffmpeg -i ... -map 0 -flags +global_header -c:v libx264 -c:a aac
2288 -f tee "[bsfs/v=dump_extra=freq=keyframe]out.ts|[movflags=+faststart]out.mp4|[select=\'a:1\']out.aac"
2292 @section webm_dash_manifest
2294 WebM DASH Manifest muxer.
2296 This muxer implements the WebM DASH Manifest specification to generate the DASH
2297 manifest XML. It also supports manifest generation for DASH live streams.
2299 For more information see:
2303 WebM DASH Specification: @url{https://sites.google.com/a/webmproject.org/wiki/adaptive-streaming/webm-dash-specification}
2305 ISO DASH Specification: @url{http://standards.iso.org/ittf/PubliclyAvailableStandards/c065274_ISO_IEC_23009-1_2014.zip}
2310 This muxer supports the following options:
2313 @item adaptation_sets
2314 This option has the following syntax: "id=x,streams=a,b,c id=y,streams=d,e" where x and y are the
2315 unique identifiers of the adaptation sets and a,b,c,d and e are the indices of the corresponding
2316 audio and video streams. Any number of adaptation sets can be added using this option.
2319 Set this to 1 to create a live stream DASH Manifest. Default: 0.
2321 @item chunk_start_index
2322 Start index of the first chunk. This will go in the @samp{startNumber} attribute
2323 of the @samp{SegmentTemplate} element in the manifest. Default: 0.
2325 @item chunk_duration_ms
2326 Duration of each chunk in milliseconds. This will go in the @samp{duration}
2327 attribute of the @samp{SegmentTemplate} element in the manifest. Default: 1000.
2329 @item utc_timing_url
2330 URL of the page that will return the UTC timestamp in ISO format. This will go
2331 in the @samp{value} attribute of the @samp{UTCTiming} element in the manifest.
2334 @item time_shift_buffer_depth
2335 Smallest time (in seconds) shifting buffer for which any Representation is
2336 guaranteed to be available. This will go in the @samp{timeShiftBufferDepth}
2337 attribute of the @samp{MPD} element. Default: 60.
2339 @item minimum_update_period
2340 Minimum update period (in seconds) of the manifest. This will go in the
2341 @samp{minimumUpdatePeriod} attribute of the @samp{MPD} element. Default: 0.
2347 ffmpeg -f webm_dash_manifest -i video1.webm \
2348 -f webm_dash_manifest -i video2.webm \
2349 -f webm_dash_manifest -i audio1.webm \
2350 -f webm_dash_manifest -i audio2.webm \
2351 -map 0 -map 1 -map 2 -map 3 \
2353 -f webm_dash_manifest \
2354 -adaptation_sets "id=0,streams=0,1 id=1,streams=2,3" \
2360 WebM Live Chunk Muxer.
2362 This muxer writes out WebM headers and chunks as separate files which can be
2363 consumed by clients that support WebM Live streams via DASH.
2367 This muxer supports the following options:
2370 @item chunk_start_index
2371 Index of the first chunk (defaults to 0).
2374 Filename of the header where the initialization data will be written.
2376 @item audio_chunk_duration
2377 Duration of each audio chunk in milliseconds (defaults to 5000).
2382 ffmpeg -f v4l2 -i /dev/video0 \
2386 -s 640x360 -keyint_min 30 -g 30 \
2388 -header webm_live_video_360.hdr \
2389 -chunk_start_index 1 \
2390 webm_live_video_360_%d.chk \
2395 -header webm_live_audio_128.hdr \
2396 -chunk_start_index 1 \
2397 -audio_chunk_duration 1000 \
2398 webm_live_audio_128_%d.chk