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 A64 muxer for Commodore 64 video. Accepts a single @code{a64_multi} or @code{a64_multi5} codec video stream.
30 Audio Interchange File Format muxer.
34 It accepts the following options:
38 Enable ID3v2 tags writing when set to 1. Default is 0 (disabled).
41 Select ID3v2 version to write. Currently only version 3 and 4 (aka.
42 ID3v2.3 and ID3v2.4) are supported. The default is version 4.
49 Advanced Systems Format muxer.
51 Note that Windows Media Audio (wma) and Windows Media Video (wmv) use this
56 It accepts the following options:
60 Set the muxer packet size. By tuning this setting you may reduce data
61 fragmentation or muxer overhead depending on your source. Default value is
62 3200, minimum is 100, maximum is 64k.
69 Audio Video Interleaved muxer.
73 It accepts the following options:
76 @item reserve_index_space
77 Reserve the specified amount of bytes for the OpenDML master index of each
78 stream within the file header. By default additional master indexes are
79 embedded within the data packets if there is no space left in the first master
80 index and are linked together as a chain of indexes. This index structure can
81 cause problems for some use cases, e.g. third-party software strictly relying
82 on the OpenDML index specification or when file seeking is slow. Reserving
83 enough index space in the file header avoids these problems.
85 The required index space depends on the output file size and should be about 16
86 bytes per gigabyte. When this option is omitted or set to zero the necessary
87 index space is guessed.
89 @item write_channel_mask
90 Write the channel layout mask into the audio stream header.
92 This option is enabled by default. Disabling the channel mask can be useful in
93 specific scenarios, e.g. when merging multiple audio streams into one for
94 compatibility with software that only supports a single audio stream in AVI
95 (see @ref{amerge,,the "amerge" section in the ffmpeg-filters manual,ffmpeg-filters}).
98 If set to true, store positive height for raw RGB bitmaps, which indicates
99 bitmap is stored bottom-up. Note that this option does not flip the bitmap
100 which has to be done manually beforehand, e.g. by using the vflip filter.
101 Default is @var{false} and indicates bitmap is stored top down.
108 Chromaprint fingerprinter.
110 This muxer feeds audio data to the Chromaprint library,
111 which generates a fingerprint for the provided audio data. See @url{https://acoustid.org/chromaprint}
113 It takes a single signed native-endian 16-bit raw audio stream of at most 2 channels.
118 @item silence_threshold
119 Threshold for detecting silence. Range is from -1 to 32767, where -1 disables
120 silence detection. Silence detection can only be used with version 3 of the
122 Silence detection must be disabled for use with the AcoustID service. Default is -1.
125 Version of algorithm to fingerprint with. Range is 0 to 4.
126 Version 3 enables silence detection. Default is 1.
129 Format to output the fingerprint as. Accepts the following options:
132 Binary raw fingerprint
135 Binary compressed fingerprint
138 Base64 compressed fingerprint @emph{(default)}
147 CRC (Cyclic Redundancy Check) testing format.
149 This muxer computes and prints the Adler-32 CRC of all the input audio
150 and video frames. By default audio frames are converted to signed
151 16-bit raw audio and video frames to raw video before computing the
154 The output of the muxer consists of a single line of the form:
155 CRC=0x@var{CRC}, where @var{CRC} is a hexadecimal number 0-padded to
156 8 digits containing the CRC for all the decoded input frames.
158 See also the @ref{framecrc} muxer.
162 For example to compute the CRC of the input, and store it in the file
165 ffmpeg -i INPUT -f crc out.crc
168 You can print the CRC to stdout with the command:
170 ffmpeg -i INPUT -f crc -
173 You can select the output format of each frame with @command{ffmpeg} by
174 specifying the audio and video codec and format. For example to
175 compute the CRC of the input audio converted to PCM unsigned 8-bit
176 and the input video converted to MPEG-2 video, use the command:
178 ffmpeg -i INPUT -c:a pcm_u8 -c:v mpeg2video -f crc -
183 Adobe Flash Video Format muxer.
185 This muxer accepts the following options:
189 @item flvflags @var{flags}
194 @item aac_seq_header_detect
195 Place AAC sequence header based on audio stream data.
197 @item no_sequence_end
198 Disable sequence end tag.
201 Disable metadata tag.
203 @item no_duration_filesize
204 Disable duration and filesize in metadata when they are equal to zero
205 at the end of stream. (Be used to non-seekable living stream).
207 @item add_keyframe_index
208 Used to facilitate seeking; particularly for HTTP pseudo streaming.
215 Dynamic Adaptive Streaming over HTTP (DASH) muxer that creates segments
216 and manifest files according to the MPEG-DASH standard ISO/IEC 23009-1:2014.
218 For more information see:
222 ISO DASH Specification: @url{http://standards.iso.org/ittf/PubliclyAvailableStandards/c065274_ISO_IEC_23009-1_2014.zip}
224 WebM DASH Specification: @url{https://sites.google.com/a/webmproject.org/wiki/adaptive-streaming/webm-dash-specification}
227 It creates a MPD manifest file and segment files for each stream.
229 The segment filename might contain pre-defined identifiers used with SegmentTemplate
230 as defined in section 5.3.9.4.4 of the standard. Available identifiers are "$RepresentationID$",
231 "$Number$", "$Bandwidth$" and "$Time$".
232 In addition to the standard identifiers, an ffmpeg-specific "$ext$" identifier is also supported.
233 When specified ffmpeg will replace $ext$ in the file name with muxing format's extensions such as mp4, webm etc.,
236 ffmpeg -re -i <input> -map 0 -map 0 -c:a libfdk_aac -c:v libx264 \
237 -b:v:0 800k -b:v:1 300k -s:v:1 320x170 -profile:v:1 baseline \
238 -profile:v:0 main -bf 1 -keyint_min 120 -g 120 -sc_threshold 0 \
239 -b_strategy 0 -ar:a:1 22050 -use_timeline 1 -use_template 1 \
240 -window_size 5 -adaptation_sets "id=0,streams=v id=1,streams=a" \
241 -f dash /path/to/out.mpd
245 @item min_seg_duration @var{microseconds}
246 This is a deprecated option to set the segment length in microseconds, use @var{seg_duration} instead.
247 @item seg_duration @var{duration}
248 Set the segment length in seconds (fractional value can be set). The value is
249 treated as average segment duration when @var{use_template} is enabled and
250 @var{use_timeline} is disabled and as minimum segment duration for all the other
252 @item frag_duration @var{duration}
253 Set the length in seconds of fragments within segments (fractional value can be set).
254 @item frag_type @var{type}
255 Set the type of interval for fragmentation.
256 @item window_size @var{size}
257 Set the maximum number of segments kept in the manifest.
258 @item extra_window_size @var{size}
259 Set the maximum number of segments kept outside of the manifest before removing from disk.
260 @item remove_at_exit @var{remove}
261 Enable (1) or disable (0) removal of all segments when finished.
262 @item use_template @var{template}
263 Enable (1) or disable (0) use of SegmentTemplate instead of SegmentList.
264 @item use_timeline @var{timeline}
265 Enable (1) or disable (0) use of SegmentTimeline in SegmentTemplate.
266 @item single_file @var{single_file}
267 Enable (1) or disable (0) storing all segments in one file, accessed using byte ranges.
268 @item single_file_name @var{file_name}
269 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.
270 @item init_seg_name @var{init_name}
271 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.
272 @item media_seg_name @var{segment_name}
273 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.
274 @item utc_timing_url @var{utc_url}
275 URL of the page that will return the UTC timestamp in ISO format. Example: "https://time.akamai.com/?iso"
276 @item method @var{method}
277 Use the given HTTP method to create output files. Generally set to PUT or POST.
278 @item http_user_agent @var{user_agent}
279 Override User-Agent field in HTTP header. Applicable only for HTTP output.
280 @item http_persistent @var{http_persistent}
281 Use persistent HTTP connections. Applicable only for HTTP output.
282 @item hls_playlist @var{hls_playlist}
283 Generate HLS playlist files as well. The master playlist is generated with the filename @var{hls_master_name}.
284 One media playlist file is generated for each stream with filenames media_0.m3u8, media_1.m3u8, etc.
285 @item hls_master_name @var{file_name}
286 HLS master playlist name. Default is "master.m3u8".
287 @item streaming @var{streaming}
288 Enable (1) or disable (0) chunk streaming mode of output. In chunk streaming
289 mode, each frame will be a moof fragment which forms a chunk.
290 @item adaptation_sets @var{adaptation_sets}
291 Assign streams to AdaptationSets. Syntax is "id=x,streams=a,b,c id=y,streams=d,e" with x and y being the IDs
292 of the adaptation sets and a,b,c,d and e are the indices of the mapped streams.
294 To map all video (or audio) streams to an AdaptationSet, "v" (or "a") can be used as stream identifier instead of IDs.
296 When no assignment is defined, this defaults to an AdaptationSet for each stream.
298 Optional syntax is "id=x,seg_duration=x,frag_duration=x,frag_type=type,descriptor=descriptor_string,streams=a,b,c id=y,seg_duration=y,frag_type=type,streams=d,e" and so on,
299 descriptor is useful to the scheme defined by ISO/IEC 23009-1:2014/Amd.2:2015.
300 For example, -adaptation_sets "id=0,descriptor=<SupplementalProperty schemeIdUri=\"urn:mpeg:dash:srd:2014\" value=\"0,0,0,1,1,2,2\"/>,streams=v".
301 Please note that descriptor string should be a self-closing xml tag.
302 seg_duration, frag_duration and frag_type override the global option values for each adaptation set.
303 For example, -adaptation_sets "id=0,seg_duration=2,frag_duration=1,frag_type=duration,streams=v id=1,seg_duration=2,frag_type=none,streams=a"
304 type_id marks an adaptation set as containing streams meant to be used for Trick Mode for the referenced adaptation set.
305 For example, -adaptation_sets "id=0,seg_duration=2,frag_type=none,streams=0 id=1,seg_duration=10,frag_type=none,trick_id=0,streams=1"
306 @item timeout @var{timeout}
307 Set timeout for socket I/O operations. Applicable only for HTTP output.
308 @item index_correction @var{index_correction}
309 Enable (1) or Disable (0) segment index correction logic. Applicable only when
310 @var{use_template} is enabled and @var{use_timeline} is disabled.
312 When enabled, the logic monitors the flow of segment indexes. If a streams's
313 segment index value is not at the expected real time position, then the logic
314 corrects that index value.
316 Typically this logic is needed in live streaming use cases. The network bandwidth
317 fluctuations are common during long run streaming. Each fluctuation can cause
318 the segment indexes fall behind the expected real time position.
319 @item format_options @var{options_list}
320 Set container format (mp4/webm) options using a @code{:} separated list of
321 key=value parameters. Values containing @code{:} special characters must be
324 @item global_sidx @var{global_sidx}
325 Write global SIDX atom. Applicable only for single file, mp4 output, non-streaming mode.
327 @item dash_segment_type @var{dash_segment_type}
331 If this flag is set, the dash segment files format will be selected based on the stream codec. This is the default mode.
334 If this flag is set, the dash segment files will be in in ISOBMFF format.
337 If this flag is set, the dash segment files will be in in WebM format.
340 @item ignore_io_errors @var{ignore_io_errors}
341 Ignore IO errors during open and write. Useful for long-duration runs with network output.
343 @item lhls @var{lhls}
344 Enable Low-latency HLS(LHLS). Adds #EXT-X-PREFETCH tag with current segment's URI.
345 Apple doesn't have an official spec for LHLS. Meanwhile hls.js player folks are
346 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
347 This option will also try to comply with the above open spec, till Apple's spec officially supports it.
348 Applicable only when @var{streaming} and @var{hls_playlist} options are enabled.
349 This is an experimental feature.
351 @item ldash @var{ldash}
352 Enable Low-latency Dash by constraining the presence and values of some elements.
354 @item master_m3u8_publish_rate @var{master_m3u8_publish_rate}
355 Publish master playlist repeatedly every after specified number of segment intervals.
357 @item write_prft @var{write_prft}
358 Write Producer Reference Time elements on supported streams. This also enables writing
359 prft boxes in the underlying muxer. Applicable only when the @var{utc_url} option is enabled.
360 It's set to auto by default, in which case the muxer will attempt to enable it only in modes
363 @item mpd_profile @var{mpd_profile}
364 Set one or more manifest profiles.
366 @item http_opts @var{http_opts}
367 A :-separated list of key=value options to pass to the underlying HTTP
368 protocol. Applicable only for HTTP output.
370 @item target_latency @var{target_latency}
371 Set an intended target latency in seconds (fractional value can be set) for serving. Applicable only when @var{streaming} and @var{write_prft} options are enabled.
372 This is an informative fields clients can use to measure the latency of the service.
374 @item min_playback_rate @var{min_playback_rate}
375 Set the minimum playback rate indicated as appropriate for the purposes of automatically
376 adjusting playback latency and buffer occupancy during normal playback by clients.
378 @item max_playback_rate @var{max_playback_rate}
379 Set the maximum playback rate indicated as appropriate for the purposes of automatically
380 adjusting playback latency and buffer occupancy during normal playback by clients.
382 @item update_period @var{update_period}
383 Set the mpd update period ,for dynamic content.
391 Per-packet CRC (Cyclic Redundancy Check) testing format.
393 This muxer computes and prints the Adler-32 CRC for each audio
394 and video packet. By default audio frames are converted to signed
395 16-bit raw audio and video frames to raw video before computing the
398 The output of the muxer consists of a line for each audio and video
401 @var{stream_index}, @var{packet_dts}, @var{packet_pts}, @var{packet_duration}, @var{packet_size}, 0x@var{CRC}
404 @var{CRC} is a hexadecimal number 0-padded to 8 digits containing the
409 For example to compute the CRC of the audio and video frames in
410 @file{INPUT}, converted to raw audio and video packets, and store it
411 in the file @file{out.crc}:
413 ffmpeg -i INPUT -f framecrc out.crc
416 To print the information to stdout, use the command:
418 ffmpeg -i INPUT -f framecrc -
421 With @command{ffmpeg}, you can select the output format to which the
422 audio and video frames are encoded before computing the CRC for each
423 packet by specifying the audio and video codec. For example, to
424 compute the CRC of each decoded input audio frame converted to PCM
425 unsigned 8-bit and of each decoded input video frame converted to
426 MPEG-2 video, use the command:
428 ffmpeg -i INPUT -c:a pcm_u8 -c:v mpeg2video -f framecrc -
431 See also the @ref{crc} muxer.
436 Per-packet hash testing format.
438 This muxer computes and prints a cryptographic hash for each audio
439 and video packet. This can be used for packet-by-packet equality
440 checks without having to individually do a binary comparison on each.
442 By default audio frames are converted to signed 16-bit raw audio and
443 video frames to raw video before computing the hash, but the output
444 of explicit conversions to other codecs can also be used. It uses the
445 SHA-256 cryptographic hash function by default, but supports several
448 The output of the muxer consists of a line for each audio and video
451 @var{stream_index}, @var{packet_dts}, @var{packet_pts}, @var{packet_duration}, @var{packet_size}, @var{hash}
454 @var{hash} is a hexadecimal number representing the computed hash
458 @item hash @var{algorithm}
459 Use the cryptographic hash function specified by the string @var{algorithm}.
460 Supported values include @code{MD5}, @code{murmur3}, @code{RIPEMD128},
461 @code{RIPEMD160}, @code{RIPEMD256}, @code{RIPEMD320}, @code{SHA160},
462 @code{SHA224}, @code{SHA256} (default), @code{SHA512/224}, @code{SHA512/256},
463 @code{SHA384}, @code{SHA512}, @code{CRC32} and @code{adler32}.
469 To compute the SHA-256 hash of the audio and video frames in @file{INPUT},
470 converted to raw audio and video packets, and store it in the file
473 ffmpeg -i INPUT -f framehash out.sha256
476 To print the information to stdout, using the MD5 hash function, use
479 ffmpeg -i INPUT -f framehash -hash md5 -
482 See also the @ref{hash} muxer.
487 Per-packet MD5 testing format.
489 This is a variant of the @ref{framehash} muxer. Unlike that muxer,
490 it defaults to using the MD5 hash function.
494 To compute the MD5 hash of the audio and video frames in @file{INPUT},
495 converted to raw audio and video packets, and store it in the file
498 ffmpeg -i INPUT -f framemd5 out.md5
501 To print the information to stdout, use the command:
503 ffmpeg -i INPUT -f framemd5 -
506 See also the @ref{framehash} and @ref{md5} muxers.
513 It accepts the following options:
517 Set the number of times to loop the output. Use @code{-1} for no loop, @code{0}
518 for looping indefinitely (default).
521 Force the delay (expressed in centiseconds) after the last frame. Each frame
522 ends with a delay until the next frame. The default is @code{-1}, which is a
523 special value to tell the muxer to re-use the previous delay. In case of a
524 loop, you might want to customize this value to mark a pause for instance.
527 For example, to encode a gif looping 10 times, with a 5 seconds delay between
530 ffmpeg -i INPUT -loop 10 -final_delay 500 out.gif
533 Note 1: if you wish to extract the frames into separate GIF files, you need to
534 force the @ref{image2} muxer:
536 ffmpeg -i INPUT -c:v gif -f image2 "out%d.gif"
539 Note 2: the GIF format has a very large time base: the delay between two frames
540 can therefore not be smaller than one centi second.
547 This muxer computes and prints a cryptographic hash of all the input
548 audio and video frames. This can be used for equality checks without
549 having to do a complete binary comparison.
551 By default audio frames are converted to signed 16-bit raw audio and
552 video frames to raw video before computing the hash, but the output
553 of explicit conversions to other codecs can also be used. Timestamps
554 are ignored. It uses the SHA-256 cryptographic hash function by default,
555 but supports several other algorithms.
557 The output of the muxer consists of a single line of the form:
558 @var{algo}=@var{hash}, where @var{algo} is a short string representing
559 the hash function used, and @var{hash} is a hexadecimal number
560 representing the computed hash.
563 @item hash @var{algorithm}
564 Use the cryptographic hash function specified by the string @var{algorithm}.
565 Supported values include @code{MD5}, @code{murmur3}, @code{RIPEMD128},
566 @code{RIPEMD160}, @code{RIPEMD256}, @code{RIPEMD320}, @code{SHA160},
567 @code{SHA224}, @code{SHA256} (default), @code{SHA512/224}, @code{SHA512/256},
568 @code{SHA384}, @code{SHA512}, @code{CRC32} and @code{adler32}.
574 To compute the SHA-256 hash of the input converted to raw audio and
575 video, and store it in the file @file{out.sha256}:
577 ffmpeg -i INPUT -f hash out.sha256
580 To print an MD5 hash to stdout use the command:
582 ffmpeg -i INPUT -f hash -hash md5 -
585 See also the @ref{framehash} muxer.
590 Apple HTTP Live Streaming muxer that segments MPEG-TS according to
591 the HTTP Live Streaming (HLS) specification.
593 It creates a playlist file, and one or more segment files. The output filename
594 specifies the playlist filename.
596 By default, the muxer creates a file for each segment produced. These files
597 have the same name as the playlist, followed by a sequential number and a
600 Make sure to require a closed GOP when encoding and to set the GOP
601 size to fit your segment time constraint.
603 For example, to convert an input file with @command{ffmpeg}:
605 ffmpeg -i in.mkv -c:v h264 -flags +cgop -g 30 -hls_time 1 out.m3u8
607 This example will produce the playlist, @file{out.m3u8}, and segment files:
608 @file{out0.ts}, @file{out1.ts}, @file{out2.ts}, etc.
610 See also the @ref{segment} muxer, which provides a more generic and
611 flexible implementation of a segmenter, and can be used to perform HLS
616 This muxer supports the following options:
619 @item hls_init_time @var{duration}
620 Set the initial target segment length. Default value is @var{0}.
622 @var{duration} must be a time duration specification,
623 see @ref{time duration syntax,,the Time duration section in the ffmpeg-utils(1) manual,ffmpeg-utils}.
625 Segment will be cut on the next key frame after this time has passed on the first m3u8 list.
626 After the initial playlist is filled @command{ffmpeg} will cut segments
627 at duration equal to @code{hls_time}
629 @item hls_time @var{duration}
630 Set the target segment length. Default value is 2.
632 @var{duration} must be a time duration specification,
633 see @ref{time duration syntax,,the Time duration section in the ffmpeg-utils(1) manual,ffmpeg-utils}.
634 Segment will be cut on the next key frame after this time has passed.
636 @item hls_list_size @var{size}
637 Set the maximum number of playlist entries. If set to 0 the list file
638 will contain all the segments. Default value is 5.
640 @item hls_delete_threshold @var{size}
641 Set the number of unreferenced segments to keep on disk before @code{hls_flags delete_segments}
642 deletes them. Increase this to allow continue clients to download segments which
643 were recently referenced in the playlist. Default value is 1, meaning segments older than
644 @code{hls_list_size+1} will be deleted.
646 @item hls_ts_options @var{options_list}
647 Set output format options using a :-separated list of key=value
648 parameters. Values containing @code{:} special characters must be
651 @item hls_wrap @var{wrap}
652 This is a deprecated option, you can use @code{hls_list_size}
653 and @code{hls_flags delete_segments} instead it
655 This option is useful to avoid to fill the disk with many segment
656 files, and limits the maximum number of segment files written to disk
660 @item hls_start_number_source
661 Start the playlist sequence number (@code{#EXT-X-MEDIA-SEQUENCE}) according to the specified source.
662 Unless @code{hls_flags single_file} is set, it also specifies source of starting sequence numbers of
663 segment and subtitle filenames. In any case, if @code{hls_flags append_list}
664 is set and read playlist sequence number is greater than the specified start sequence number,
665 then that value will be used as start value.
667 It accepts the following values:
671 @item generic (default)
672 Set the starting sequence numbers according to @var{start_number} option value.
675 The start number will be the seconds since epoch (1970-01-01 00:00:00)
678 The start number will be the microseconds since epoch (1970-01-01 00:00:00)
681 The start number will be based on the current date/time as YYYYmmddHHMMSS. e.g. 20161231235759.
685 @item start_number @var{number}
686 Start the playlist sequence number (@code{#EXT-X-MEDIA-SEQUENCE}) from the specified @var{number}
687 when @var{hls_start_number_source} value is @var{generic}. (This is the default case.)
688 Unless @code{hls_flags single_file} is set, it also specifies starting sequence numbers of segment and subtitle filenames.
691 @item hls_allow_cache @var{allowcache}
692 Explicitly set whether the client MAY (1) or MUST NOT (0) cache media segments.
694 @item hls_base_url @var{baseurl}
695 Append @var{baseurl} to every entry in the playlist.
696 Useful to generate playlists with absolute paths.
698 Note that the playlist sequence number must be unique for each segment
699 and it is not to be confused with the segment filename sequence number
700 which can be cyclic, for example if the @option{wrap} option is
703 @item hls_segment_filename @var{filename}
704 Set the segment filename. Unless @code{hls_flags single_file} is set,
705 @var{filename} is used as a string format with the segment number:
707 ffmpeg -i in.nut -hls_segment_filename 'file%03d.ts' out.m3u8
709 This example will produce the playlist, @file{out.m3u8}, and segment files:
710 @file{file000.ts}, @file{file001.ts}, @file{file002.ts}, etc.
712 @var{filename} may contain full path or relative path specification,
713 but only the file name part without any path info will be contained in the m3u8 segment list.
714 Should a relative path be specified, the path of the created segment
715 files will be relative to the current working directory.
716 When strftime_mkdir is set, the whole expanded value of @var{filename} will be written into the m3u8 segment list.
718 When @code{var_stream_map} is set with two or more variant streams, the
719 @var{filename} pattern must contain the string "%v", this string specifies
720 the position of variant stream index in the generated segment file names.
722 ffmpeg -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k -b:a:1 32k \
723 -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" \
724 -hls_segment_filename 'file_%v_%03d.ts' out_%v.m3u8
726 This example will produce the playlists segment file sets:
727 @file{file_0_000.ts}, @file{file_0_001.ts}, @file{file_0_002.ts}, etc. and
728 @file{file_1_000.ts}, @file{file_1_001.ts}, @file{file_1_002.ts}, etc.
730 The string "%v" may be present in the filename or in the last directory name
731 containing the file, but only in one of them. (Additionally, %v may appear multiple times in the last
732 sub-directory or filename.) If the string %v is present in the directory name, then
733 sub-directories are created after expanding the directory name pattern. This
734 enables creation of segments corresponding to different variant streams in
737 ffmpeg -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k -b:a:1 32k \
738 -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" \
739 -hls_segment_filename 'vs%v/file_%03d.ts' vs%v/out.m3u8
741 This example will produce the playlists segment file sets:
742 @file{vs0/file_000.ts}, @file{vs0/file_001.ts}, @file{vs0/file_002.ts}, etc. and
743 @file{vs1/file_000.ts}, @file{vs1/file_001.ts}, @file{vs1/file_002.ts}, etc.
746 Same as strftime option, will be deprecated.
749 Use strftime() on @var{filename} to expand the segment filename with localtime.
750 The segment number is also available in this mode, but to use it, you need to specify second_level_segment_index
751 hls_flag and %%d will be the specifier.
753 ffmpeg -i in.nut -strftime 1 -hls_segment_filename 'file-%Y%m%d-%s.ts' out.m3u8
755 This example will produce the playlist, @file{out.m3u8}, and segment files:
756 @file{file-20160215-1455569023.ts}, @file{file-20160215-1455569024.ts}, etc.
757 Note: On some systems/environments, the @code{%s} specifier is not available. See
758 @code{strftime()} documentation.
760 ffmpeg -i in.nut -strftime 1 -hls_flags second_level_segment_index -hls_segment_filename 'file-%Y%m%d-%%04d.ts' out.m3u8
762 This example will produce the playlist, @file{out.m3u8}, and segment files:
763 @file{file-20160215-0001.ts}, @file{file-20160215-0002.ts}, etc.
765 @item use_localtime_mkdir
766 Same as strftime_mkdir option, will be deprecated .
769 Used together with -strftime_mkdir, it will create all subdirectories which
770 is expanded in @var{filename}.
772 ffmpeg -i in.nut -strftime 1 -strftime_mkdir 1 -hls_segment_filename '%Y%m%d/file-%Y%m%d-%s.ts' out.m3u8
774 This example will create a directory 201560215 (if it does not exist), and then
775 produce the playlist, @file{out.m3u8}, and segment files:
776 @file{20160215/file-20160215-1455569023.ts}, @file{20160215/file-20160215-1455569024.ts}, etc.
779 ffmpeg -i in.nut -strftime 1 -strftime_mkdir 1 -hls_segment_filename '%Y/%m/%d/file-%Y%m%d-%s.ts' out.m3u8
781 This example will create a directory hierarchy 2016/02/15 (if any of them do not exist), and then
782 produce the playlist, @file{out.m3u8}, and segment files:
783 @file{2016/02/15/file-20160215-1455569023.ts}, @file{2016/02/15/file-20160215-1455569024.ts}, etc.
786 @item hls_key_info_file @var{key_info_file}
787 Use the information in @var{key_info_file} for segment encryption. The first
788 line of @var{key_info_file} specifies the key URI written to the playlist. The
789 key URL is used to access the encryption key during playback. The second line
790 specifies the path to the key file used to obtain the key during the encryption
791 process. The key file is read as a single packed array of 16 octets in binary
792 format. The optional third line specifies the initialization vector (IV) as a
793 hexadecimal string to be used instead of the segment sequence number (default)
794 for encryption. Changes to @var{key_info_file} will result in segment
795 encryption with the new key/IV and an entry in the playlist for the new key
796 URI/IV if @code{hls_flags periodic_rekey} is enabled.
798 Key info file format:
807 http://server/file.key
812 Example key file paths:
820 0123456789ABCDEF0123456789ABCDEF
823 Key info file example:
825 http://server/file.key
827 0123456789ABCDEF0123456789ABCDEF
830 Example shell script:
834 openssl rand 16 > file.key
835 echo $BASE_URL/file.key > file.keyinfo
836 echo file.key >> file.keyinfo
837 echo $(openssl rand -hex 16) >> file.keyinfo
838 ffmpeg -f lavfi -re -i testsrc -c:v h264 -hls_flags delete_segments \
839 -hls_key_info_file file.keyinfo out.m3u8
842 @item -hls_enc @var{enc}
843 Enable (1) or disable (0) the AES128 encryption.
844 When enabled every segment generated is encrypted and the encryption key
845 is saved as @var{playlist name}.key.
847 @item -hls_enc_key @var{key}
848 16-octet key to encrypt the segments, by default it
849 is randomly generated.
851 @item -hls_enc_key_url @var{keyurl}
852 If set, @var{keyurl} is prepended instead of @var{baseurl} to the key filename
855 @item -hls_enc_iv @var{iv}
856 16-octet initialization vector for every segment instead
857 of the autogenerated ones.
859 @item hls_segment_type @var{flags}
864 Output segment files in MPEG-2 Transport Stream format. This is
865 compatible with all HLS versions.
868 Output segment files in fragmented MP4 format, similar to MPEG-DASH.
869 fmp4 files may be used in HLS version 7 and above.
873 @item hls_fmp4_init_filename @var{filename}
874 Set filename to the fragment files header file, default filename is @file{init.mp4}.
876 Use @code{-strftime 1} on @var{filename} to expand the segment filename with localtime.
878 ffmpeg -i in.nut -hls_segment_type fmp4 -strftime 1 -hls_fmp4_init_filename "%s_init.mp4" out.m3u8
880 This will produce init like this
881 @file{1602678741_init.mp4}
883 @item hls_fmp4_init_resend
884 Resend init file after m3u8 file refresh every time, default is @var{0}.
886 When @code{var_stream_map} is set with two or more variant streams, the
887 @var{filename} pattern must contain the string "%v", this string specifies
888 the position of variant stream index in the generated init file names.
889 The string "%v" may be present in the filename or in the last directory name
890 containing the file. If the string is present in the directory name, then
891 sub-directories are created after expanding the directory name pattern. This
892 enables creation of init files corresponding to different variant streams in
895 @item hls_flags @var{flags}
900 If this flag is set, the muxer will store all segments in a single MPEG-TS
901 file, and will use byte ranges in the playlist. HLS playlists generated with
902 this way will have the version number 4.
905 ffmpeg -i in.nut -hls_flags single_file out.m3u8
907 Will produce the playlist, @file{out.m3u8}, and a single segment file,
910 @item delete_segments
911 Segment files removed from the playlist are deleted after a period of time
912 equal to the duration of the segment plus the duration of the playlist.
915 Append new segments into the end of old segment list,
916 and remove the @code{#EXT-X-ENDLIST} from the old segment list.
918 @item round_durations
919 Round the duration info in the playlist file segment info to integer
920 values, instead of using floating point.
923 Add the @code{#EXT-X-DISCONTINUITY} tag to the playlist, before the
924 first segment's information.
927 Do not append the @code{EXT-X-ENDLIST} tag at the end of the playlist.
930 The file specified by @code{hls_key_info_file} will be checked periodically and
931 detect updates to the encryption info. Be sure to replace this file atomically,
932 including the file containing the AES encryption key.
934 @item independent_segments
935 Add the @code{#EXT-X-INDEPENDENT-SEGMENTS} to playlists that has video segments
936 and when all the segments of that playlist are guaranteed to start with a Key frame.
939 Add the @code{#EXT-X-I-FRAMES-ONLY} to playlists that has video segments
940 and can play only I-frames in the @code{#EXT-X-BYTERANGE} mode.
943 Allow segments to start on frames other than keyframes. This improves
944 behavior on some players when the time between keyframes is inconsistent,
945 but may make things worse on others, and can cause some oddities during
946 seeking. This flag should be used with the @code{hls_time} option.
948 @item program_date_time
949 Generate @code{EXT-X-PROGRAM-DATE-TIME} tags.
951 @item second_level_segment_index
952 Makes it possible to use segment indexes as %%d in hls_segment_filename expression
953 besides date/time values when strftime is on.
954 To get fixed width numbers with trailing zeroes, %%0xd format is available where x is the required width.
956 @item second_level_segment_size
957 Makes it possible to use segment sizes (counted in bytes) as %%s in hls_segment_filename
958 expression besides date/time values when strftime is on.
959 To get fixed width numbers with trailing zeroes, %%0xs format is available where x is the required width.
961 @item second_level_segment_duration
962 Makes it possible to use segment duration (calculated in microseconds) as %%t in hls_segment_filename
963 expression besides date/time values when strftime is on.
964 To get fixed width numbers with trailing zeroes, %%0xt format is available where x is the required width.
967 ffmpeg -i sample.mpeg \
968 -f hls -hls_time 3 -hls_list_size 5 \
969 -hls_flags second_level_segment_index+second_level_segment_size+second_level_segment_duration \
970 -strftime 1 -strftime_mkdir 1 -hls_segment_filename "segment_%Y%m%d%H%M%S_%%04d_%%08s_%%013t.ts" stream.m3u8
972 This will produce segments like this:
973 @file{segment_20170102194334_0003_00122200_0000003000000.ts}, @file{segment_20170102194334_0004_00120072_0000003000000.ts} etc.
976 Write segment data to filename.tmp and rename to filename only once the segment is complete. A webserver
977 serving up segments can be configured to reject requests to *.tmp to prevent access to in-progress segments
978 before they have been added to the m3u8 playlist. This flag also affects how m3u8 playlist files are created.
979 If this flag is set, all playlist files will written into temporary file and renamed after they are complete, similarly as segments are handled.
980 But playlists with @code{file} protocol and with type (@code{hls_playlist_type}) other than @code{vod}
981 are always written into temporary file regardless of this flag. Master playlist files (@code{master_pl_name}), if any, with @code{file} protocol,
982 are always written into temporary file regardless of this flag if @code{master_pl_publish_rate} value is other than zero.
986 @item hls_playlist_type event
987 Emit @code{#EXT-X-PLAYLIST-TYPE:EVENT} in the m3u8 header. Forces
988 @option{hls_list_size} to 0; the playlist can only be appended to.
990 @item hls_playlist_type vod
991 Emit @code{#EXT-X-PLAYLIST-TYPE:VOD} in the m3u8 header. Forces
992 @option{hls_list_size} to 0; the playlist must not change.
995 Use the given HTTP method to create the hls files.
997 ffmpeg -re -i in.ts -f hls -method PUT http://example.com/live/out.m3u8
999 This example will upload all the mpegts segment files to the HTTP
1000 server using the HTTP PUT method, and update the m3u8 files every
1001 @code{refresh} times using the same method.
1002 Note that the HTTP server must support the given method for uploading
1005 @item http_user_agent
1006 Override User-Agent field in HTTP header. Applicable only for HTTP output.
1008 @item var_stream_map
1009 Map string which specifies how to group the audio, video and subtitle streams
1010 into different variant streams. The variant stream groups are separated
1012 Expected string format is like this "a:0,v:0 a:1,v:1 ....". Here a:, v:, s: are
1013 the keys to specify audio, video and subtitle streams respectively.
1014 Allowed values are 0 to 9 (limited just based on practical usage).
1016 When there are two or more variant streams, the output filename pattern must
1017 contain the string "%v", this string specifies the position of variant stream
1018 index in the output media playlist filenames. The string "%v" may be present in
1019 the filename or in the last directory name containing the file. If the string is
1020 present in the directory name, then sub-directories are created after expanding
1021 the directory name pattern. This enables creation of variant streams in
1025 ffmpeg -re -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k -b:a:1 32k \
1026 -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" \
1027 http://example.com/live/out_%v.m3u8
1029 This example creates two hls variant streams. The first variant stream will
1030 contain video stream of bitrate 1000k and audio stream of bitrate 64k and the
1031 second variant stream will contain video stream of bitrate 256k and audio
1032 stream of bitrate 32k. Here, two media playlist with file names out_0.m3u8 and
1033 out_1.m3u8 will be created. If you want something meaningful text instead of indexes
1034 in result names, you may specify names for each or some of the variants
1035 as in the following example.
1039 ffmpeg -re -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k -b:a:1 32k \
1040 -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" \
1041 http://example.com/live/out_%v.m3u8
1044 This example creates two hls variant streams as in the previous one.
1045 But here, the two media playlist with file names out_my_hd.m3u8 and
1046 out_my_sd.m3u8 will be created.
1049 ffmpeg -re -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k \
1050 -map 0:v -map 0:a -map 0:v -f hls -var_stream_map "v:0 a:0 v:1" \
1051 http://example.com/live/out_%v.m3u8
1053 This example creates three hls variant streams. The first variant stream will
1054 be a video only stream with video bitrate 1000k, the second variant stream will
1055 be an audio only stream with bitrate 64k and the third variant stream will be a
1056 video only stream with bitrate 256k. Here, three media playlist with file names
1057 out_0.m3u8, out_1.m3u8 and out_2.m3u8 will be created.
1059 ffmpeg -re -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k -b:a:1 32k \
1060 -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" \
1061 http://example.com/live/vs_%v/out.m3u8
1063 This example creates the variant streams in subdirectories. Here, the first
1064 media playlist is created at @file{http://example.com/live/vs_0/out.m3u8} and
1065 the second one at @file{http://example.com/live/vs_1/out.m3u8}.
1067 ffmpeg -re -i in.ts -b:a:0 32k -b:a:1 64k -b:v:0 1000k -b:v:1 3000k \
1068 -map 0:a -map 0:a -map 0:v -map 0:v -f hls \
1069 -var_stream_map "a:0,agroup:aud_low a:1,agroup:aud_high v:0,agroup:aud_low v:1,agroup:aud_high" \
1070 -master_pl_name master.m3u8 \
1071 http://example.com/live/out_%v.m3u8
1073 This example creates two audio only and two video only variant streams. In
1074 addition to the #EXT-X-STREAM-INF tag for each variant stream in the master
1075 playlist, #EXT-X-MEDIA tag is also added for the two audio only variant streams
1076 and they are mapped to the two video only variant streams with audio group names
1077 'aud_low' and 'aud_high'.
1079 By default, a single hls variant containing all the encoded streams is created.
1082 ffmpeg -re -i in.ts -b:a:0 32k -b:a:1 64k -b:v:0 1000k \
1083 -map 0:a -map 0:a -map 0:v -f hls \
1084 -var_stream_map "a:0,agroup:aud_low,default:yes a:1,agroup:aud_low v:0,agroup:aud_low" \
1085 -master_pl_name master.m3u8 \
1086 http://example.com/live/out_%v.m3u8
1088 This example creates two audio only and one video only variant streams. In
1089 addition to the #EXT-X-STREAM-INF tag for each variant stream in the master
1090 playlist, #EXT-X-MEDIA tag is also added for the two audio only variant streams
1091 and they are mapped to the one video only variant streams with audio group name
1092 'aud_low', and the audio group have default stat is NO or YES.
1094 By default, a single hls variant containing all the encoded streams is created.
1097 ffmpeg -re -i in.ts -b:a:0 32k -b:a:1 64k -b:v:0 1000k \
1098 -map 0:a -map 0:a -map 0:v -f hls \
1099 -var_stream_map "a:0,agroup:aud_low,default:yes,language:ENG a:1,agroup:aud_low,language:CHN v:0,agroup:aud_low" \
1100 -master_pl_name master.m3u8 \
1101 http://example.com/live/out_%v.m3u8
1103 This example creates two audio only and one video only variant streams. In
1104 addition to the #EXT-X-STREAM-INF tag for each variant stream in the master
1105 playlist, #EXT-X-MEDIA tag is also added for the two audio only variant streams
1106 and they are mapped to the one video only variant streams with audio group name
1107 'aud_low', and the audio group have default stat is NO or YES, and one audio
1108 have and language is named ENG, the other audio language is named CHN.
1110 By default, a single hls variant containing all the encoded streams is created.
1113 ffmpeg -y -i input_with_subtitle.mkv \
1114 -b:v:0 5250k -c:v h264 -pix_fmt yuv420p -profile:v main -level 4.1 \
1116 -c:s webvtt -c:a mp2 -ar 48000 -ac 2 -map 0:v -map 0:a:0 -map 0:s:0 \
1117 -f hls -var_stream_map "v:0,a:0,s:0,sgroup:subtitle" \
1118 -master_pl_name master.m3u8 -t 300 -hls_time 10 -hls_init_time 4 -hls_list_size \
1119 10 -master_pl_publish_rate 10 -hls_flags \
1120 delete_segments+discont_start+split_by_time ./tmp/video.m3u8
1123 This example adds @code{#EXT-X-MEDIA} tag with @code{TYPE=SUBTITLES} in
1124 the master playlist with webvtt subtitle group name 'subtitle'. Please make sure
1125 the input file has one text subtitle stream at least.
1128 Map string which specifies different closed captions groups and their
1129 attributes. The closed captions stream groups are separated by space.
1130 Expected string format is like this
1131 "ccgroup:<group name>,instreamid:<INSTREAM-ID>,language:<language code> ....".
1132 'ccgroup' and 'instreamid' are mandatory attributes. 'language' is an optional
1134 The closed captions groups configured using this option are mapped to different
1135 variant streams by providing the same 'ccgroup' name in the
1136 @code{var_stream_map} string. If @code{var_stream_map} is not set, then the
1137 first available ccgroup in @code{cc_stream_map} is mapped to the output variant
1138 stream. The examples for these two use cases are given below.
1141 ffmpeg -re -i in.ts -b:v 1000k -b:a 64k -a53cc 1 -f hls \
1142 -cc_stream_map "ccgroup:cc,instreamid:CC1,language:en" \
1143 -master_pl_name master.m3u8 \
1144 http://example.com/live/out.m3u8
1146 This example adds @code{#EXT-X-MEDIA} tag with @code{TYPE=CLOSED-CAPTIONS} in
1147 the master playlist with group name 'cc', language 'en' (english) and
1148 INSTREAM-ID 'CC1'. Also, it adds @code{CLOSED-CAPTIONS} attribute with group
1149 name 'cc' for the output variant stream.
1151 ffmpeg -re -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k -b:a:1 32k \
1152 -a53cc:0 1 -a53cc:1 1\
1153 -map 0:v -map 0:a -map 0:v -map 0:a -f hls \
1154 -cc_stream_map "ccgroup:cc,instreamid:CC1,language:en ccgroup:cc,instreamid:CC2,language:sp" \
1155 -var_stream_map "v:0,a:0,ccgroup:cc v:1,a:1,ccgroup:cc" \
1156 -master_pl_name master.m3u8 \
1157 http://example.com/live/out_%v.m3u8
1159 This example adds two @code{#EXT-X-MEDIA} tags with @code{TYPE=CLOSED-CAPTIONS} in
1160 the master playlist for the INSTREAM-IDs 'CC1' and 'CC2'. Also, it adds
1161 @code{CLOSED-CAPTIONS} attribute with group name 'cc' for the two output variant
1164 @item master_pl_name
1165 Create HLS master playlist with the given name.
1168 ffmpeg -re -i in.ts -f hls -master_pl_name master.m3u8 http://example.com/live/out.m3u8
1170 This example creates HLS master playlist with name master.m3u8 and it is
1171 published at http://example.com/live/
1173 @item master_pl_publish_rate
1174 Publish master play list repeatedly every after specified number of segment intervals.
1177 ffmpeg -re -i in.ts -f hls -master_pl_name master.m3u8 \
1178 -hls_time 2 -master_pl_publish_rate 30 http://example.com/live/out.m3u8
1181 This example creates HLS master playlist with name master.m3u8 and keep
1182 publishing it repeatedly every after 30 segments i.e. every after 60s.
1184 @item http_persistent
1185 Use persistent HTTP connections. Applicable only for HTTP output.
1188 Set timeout for socket I/O operations. Applicable only for HTTP output.
1190 @item -ignore_io_errors
1191 Ignore IO errors during open, write and delete. Useful for long-duration runs with network output.
1194 Set custom HTTP headers, can override built in default headers. Applicable only for HTTP output.
1203 Microsoft's icon file format (ICO) has some strict limitations that should be noted:
1207 Size cannot exceed 256 pixels in any dimension
1210 Only BMP and PNG images can be stored
1213 If a BMP image is used, it must be one of the following pixel formats:
1215 BMP Bit Depth FFmpeg Pixel Format
1225 If a BMP image is used, it must use the BITMAPINFOHEADER DIB header
1228 If a PNG image is used, it must use the rgba pixel format
1236 The image file muxer writes video frames to image files.
1238 The output filenames are specified by a pattern, which can be used to
1239 produce sequentially numbered series of files.
1240 The pattern may contain the string "%d" or "%0@var{N}d", this string
1241 specifies the position of the characters representing a numbering in
1242 the filenames. If the form "%0@var{N}d" is used, the string
1243 representing the number in each filename is 0-padded to @var{N}
1244 digits. The literal character '%' can be specified in the pattern with
1247 If the pattern contains "%d" or "%0@var{N}d", the first filename of
1248 the file list specified will contain the number 1, all the following
1249 numbers will be sequential.
1251 The pattern may contain a suffix which is used to automatically
1252 determine the format of the image files to write.
1254 For example the pattern "img-%03d.bmp" will specify a sequence of
1255 filenames of the form @file{img-001.bmp}, @file{img-002.bmp}, ...,
1256 @file{img-010.bmp}, etc.
1257 The pattern "img%%-%d.jpg" will specify a sequence of filenames of the
1258 form @file{img%-1.jpg}, @file{img%-2.jpg}, ..., @file{img%-10.jpg},
1261 The image muxer supports the .Y.U.V image file format. This format is
1262 special in that that each image frame consists of three files, for
1263 each of the YUV420P components. To read or write this image file format,
1264 specify the name of the '.Y' file. The muxer will automatically open the
1265 '.U' and '.V' files as required.
1271 If set to 1, expand the filename with pts from pkt->pts.
1275 Start the sequence from the specified number. Default value is 1.
1278 If set to 1, the filename will always be interpreted as just a
1279 filename, not a pattern, and the corresponding file will be continuously
1280 overwritten with new images. Default value is 0.
1283 If set to 1, expand the filename with date and time information from
1284 @code{strftime()}. Default value is 0.
1286 @item protocol_opts @var{options_list}
1287 Set protocol options as a :-separated list of key=value parameters. Values
1288 containing the @code{:} special character must be escaped.
1292 @subsection Examples
1294 The following example shows how to use @command{ffmpeg} for creating a
1295 sequence of files @file{img-001.jpeg}, @file{img-002.jpeg}, ...,
1296 taking one image every second from the input video:
1298 ffmpeg -i in.avi -vsync cfr -r 1 -f image2 'img-%03d.jpeg'
1301 Note that with @command{ffmpeg}, if the format is not specified with the
1302 @code{-f} option and the output filename specifies an image file
1303 format, the image2 muxer is automatically selected, so the previous
1304 command can be written as:
1306 ffmpeg -i in.avi -vsync cfr -r 1 'img-%03d.jpeg'
1309 Note also that the pattern must not necessarily contain "%d" or
1310 "%0@var{N}d", for example to create a single image file
1311 @file{img.jpeg} from the start of the input video you can employ the command:
1313 ffmpeg -i in.avi -f image2 -frames:v 1 img.jpeg
1316 The @option{strftime} option allows you to expand the filename with
1317 date and time information. Check the documentation of
1318 the @code{strftime()} function for the syntax.
1320 For example to generate image files from the @code{strftime()}
1321 "%Y-%m-%d_%H-%M-%S" pattern, the following @command{ffmpeg} command
1324 ffmpeg -f v4l2 -r 1 -i /dev/video0 -f image2 -strftime 1 "%Y-%m-%d_%H-%M-%S.jpg"
1327 You can set the file name with current frame's PTS:
1329 ffmpeg -f v4l2 -r 1 -i /dev/video0 -copyts -f image2 -frame_pts true %d.jpg"
1332 A more complex example is to publish contents of your desktop directly to a
1333 WebDAV server every second:
1335 ffmpeg -f x11grab -framerate 1 -i :0.0 -q:v 6 -update 1 -protocol_opts method=PUT http://example.com/desktop.jpg
1340 Matroska container muxer.
1342 This muxer implements the matroska and webm container specs.
1344 @subsection Metadata
1346 The recognized metadata settings in this muxer are:
1350 Set title name provided to a single track. This gets mapped to
1351 the FileDescription element for a stream written as attachment.
1354 Specify the language of the track in the Matroska languages form.
1356 The language can be either the 3 letters bibliographic ISO-639-2 (ISO
1357 639-2/B) form (like "fre" for French), or a language code mixed with a
1358 country code for specialities in languages (like "fre-ca" for Canadian
1362 Set stereo 3D video layout of two views in a single video track.
1364 The following values are recognized:
1369 Both views are arranged side by side, Left-eye view is on the left
1371 Both views are arranged in top-bottom orientation, Left-eye view is at bottom
1373 Both views are arranged in top-bottom orientation, Left-eye view is on top
1374 @item checkerboard_rl
1375 Each view is arranged in a checkerboard interleaved pattern, Left-eye view being first
1376 @item checkerboard_lr
1377 Each view is arranged in a checkerboard interleaved pattern, Right-eye view being first
1378 @item row_interleaved_rl
1379 Each view is constituted by a row based interleaving, Right-eye view is first row
1380 @item row_interleaved_lr
1381 Each view is constituted by a row based interleaving, Left-eye view is first row
1382 @item col_interleaved_rl
1383 Both views are arranged in a column based interleaving manner, Right-eye view is first column
1384 @item col_interleaved_lr
1385 Both views are arranged in a column based interleaving manner, Left-eye view is first column
1386 @item anaglyph_cyan_red
1387 All frames are in anaglyph format viewable through red-cyan filters
1389 Both views are arranged side by side, Right-eye view is on the left
1390 @item anaglyph_green_magenta
1391 All frames are in anaglyph format viewable through green-magenta filters
1393 Both eyes laced in one Block, Left-eye view is first
1395 Both eyes laced in one Block, Right-eye view is first
1399 For example a 3D WebM clip can be created using the following command line:
1401 ffmpeg -i sample_left_right_clip.mpg -an -c:v libvpx -metadata stereo_mode=left_right -y stereo_clip.webm
1406 This muxer supports the following options:
1409 @item reserve_index_space
1410 By default, this muxer writes the index for seeking (called cues in Matroska
1411 terms) at the end of the file, because it cannot know in advance how much space
1412 to leave for the index at the beginning of the file. However for some use cases
1413 -- e.g. streaming where seeking is possible but slow -- it is useful to put the
1414 index at the beginning of the file.
1416 If this option is set to a non-zero value, the muxer will reserve a given amount
1417 of space in the file header and then try to write the cues there when the muxing
1418 finishes. If the reserved space does not suffice, no Cues will be written, the
1419 file will be finalized and writing the trailer will return an error.
1420 A safe size for most use cases should be about 50kB per hour of video.
1422 Note that cues are only written if the output is seekable and this option will
1423 have no effect if it is not.
1425 This option controls how the FlagDefault of the output tracks will be set.
1426 It influences which tracks players should play by default. The default mode
1430 In this mode, for each type of track (audio, video or subtitle), if there is
1431 a track with disposition default of this type, then the first such track
1432 (i.e. the one with the lowest index) will be marked as default; if no such
1433 track exists, the first track of this type will be marked as default instead
1434 (if existing). This ensures that the default flag is set in a sensible way even
1435 if the input originated from containers that lack the concept of default tracks.
1437 This mode is the same as infer except that if no subtitle track with
1438 disposition default exists, no subtitle track will be marked as default.
1440 In this mode the FlagDefault is set if and only if the AV_DISPOSITION_DEFAULT
1441 flag is set in the disposition of the corresponding stream.
1444 @item flipped_raw_rgb
1445 If set to true, store positive height for raw RGB bitmaps, which indicates
1446 bitmap is stored bottom-up. Note that this option does not flip the bitmap
1447 which has to be done manually beforehand, e.g. by using the vflip filter.
1448 Default is @var{false} and indicates bitmap is stored top down.
1457 This is a variant of the @ref{hash} muxer. Unlike that muxer, it
1458 defaults to using the MD5 hash function.
1460 @subsection Examples
1462 To compute the MD5 hash of the input converted to raw
1463 audio and video, and store it in the file @file{out.md5}:
1465 ffmpeg -i INPUT -f md5 out.md5
1468 You can print the MD5 to stdout with the command:
1470 ffmpeg -i INPUT -f md5 -
1473 See also the @ref{hash} and @ref{framemd5} muxers.
1475 @section mov, mp4, ismv
1477 MOV/MP4/ISMV (Smooth Streaming) muxer.
1479 The mov/mp4/ismv muxer supports fragmentation. Normally, a MOV/MP4
1480 file has all the metadata about all packets stored in one location
1481 (written at the end of the file, it can be moved to the start for
1482 better playback by adding @var{faststart} to the @var{movflags}, or
1483 using the @command{qt-faststart} tool). A fragmented
1484 file consists of a number of fragments, where packets and metadata
1485 about these packets are stored together. Writing a fragmented
1486 file has the advantage that the file is decodable even if the
1487 writing is interrupted (while a normal MOV/MP4 is undecodable if
1488 it is not properly finished), and it requires less memory when writing
1489 very long files (since writing normal MOV/MP4 files stores info about
1490 every single packet in memory until the file is closed). The downside
1491 is that it is less compatible with other applications.
1495 Fragmentation is enabled by setting one of the AVOptions that define
1496 how to cut the file into fragments:
1499 @item -moov_size @var{bytes}
1500 Reserves space for the moov atom at the beginning of the file instead of placing the
1501 moov atom at the end. If the space reserved is insufficient, muxing will fail.
1502 @item -movflags frag_keyframe
1503 Start a new fragment at each video keyframe.
1504 @item -frag_duration @var{duration}
1505 Create fragments that are @var{duration} microseconds long.
1506 @item -frag_size @var{size}
1507 Create fragments that contain up to @var{size} bytes of payload data.
1508 @item -movflags frag_custom
1509 Allow the caller to manually choose when to cut fragments, by
1510 calling @code{av_write_frame(ctx, NULL)} to write a fragment with
1511 the packets written so far. (This is only useful with other
1512 applications integrating libavformat, not from @command{ffmpeg}.)
1513 @item -min_frag_duration @var{duration}
1514 Don't create fragments that are shorter than @var{duration} microseconds long.
1517 If more than one condition is specified, fragments are cut when
1518 one of the specified conditions is fulfilled. The exception to this is
1519 @code{-min_frag_duration}, which has to be fulfilled for any of the other
1520 conditions to apply.
1522 Additionally, the way the output file is written can be adjusted
1523 through a few other options:
1526 @item -movflags empty_moov
1527 Write an initial moov atom directly at the start of the file, without
1528 describing any samples in it. Generally, an mdat/moov pair is written
1529 at the start of the file, as a normal MOV/MP4 file, containing only
1530 a short portion of the file. With this option set, there is no initial
1531 mdat atom, and the moov atom only describes the tracks but has
1534 This option is implicitly set when writing ismv (Smooth Streaming) files.
1535 @item -movflags separate_moof
1536 Write a separate moof (movie fragment) atom for each track. Normally,
1537 packets for all tracks are written in a moof atom (which is slightly
1538 more efficient), but with this option set, the muxer writes one moof/mdat
1539 pair for each track, making it easier to separate tracks.
1541 This option is implicitly set when writing ismv (Smooth Streaming) files.
1542 @item -movflags skip_sidx
1543 Skip writing of sidx atom. When bitrate overhead due to sidx atom is high,
1544 this option could be used for cases where sidx atom is not mandatory.
1545 When global_sidx flag is enabled, this option will be ignored.
1546 @item -movflags faststart
1547 Run a second pass moving the index (moov atom) to the beginning of the file.
1548 This operation can take a while, and will not work in various situations such
1549 as fragmented output, thus it is not enabled by default.
1550 @item -movflags rtphint
1551 Add RTP hinting tracks to the output file.
1552 @item -movflags disable_chpl
1553 Disable Nero chapter markers (chpl atom). Normally, both Nero chapters
1554 and a QuickTime chapter track are written to the file. With this option
1555 set, only the QuickTime chapter track will be written. Nero chapters can
1556 cause failures when the file is reprocessed with certain tagging programs, like
1557 mp3Tag 2.61a and iTunes 11.3, most likely other versions are affected as well.
1558 @item -movflags omit_tfhd_offset
1559 Do not write any absolute base_data_offset in tfhd atoms. This avoids
1560 tying fragments to absolute byte positions in the file/streams.
1561 @item -movflags default_base_moof
1562 Similarly to the omit_tfhd_offset, this flag avoids writing the
1563 absolute base_data_offset field in tfhd atoms, but does so by using
1564 the new default-base-is-moof flag instead. This flag is new from
1565 14496-12:2012. This may make the fragments easier to parse in certain
1566 circumstances (avoiding basing track fragment location calculations
1567 on the implicit end of the previous track fragment).
1569 Specify @code{on} to force writing a timecode track, @code{off} to disable it
1570 and @code{auto} to write a timecode track only for mov and mp4 output (default).
1571 @item -movflags negative_cts_offsets
1572 Enables utilization of version 1 of the CTTS box, in which the CTS offsets can
1573 be negative. This enables the initial sample to have DTS/CTS of zero, and
1574 reduces the need for edit lists for some cases such as video tracks with
1575 B-frames. Additionally, eases conformance with the DASH-IF interoperability
1578 This option is implicitly set when writing ismv (Smooth Streaming) files.
1580 Write producer time reference box (PRFT) with a specified time source for the
1581 NTP field in the PRFT box. Set value as @samp{wallclock} to specify timesource
1582 as wallclock time and @samp{pts} to specify timesource as input packets' PTS
1585 Setting value to @samp{pts} is applicable only for a live encoding use case,
1586 where PTS values are set as as wallclock time at the source. For example, an
1587 encoding use case with decklink capture source where @option{video_pts} and
1588 @option{audio_pts} are set to @samp{abs_wallclock}.
1593 Smooth Streaming content can be pushed in real time to a publishing
1594 point on IIS with this muxer. Example:
1596 ffmpeg -re @var{<normal input/transcoding options>} -movflags isml+frag_keyframe -f ismv http://server/publishingpoint.isml/Streams(Encoder1)
1601 The MP3 muxer writes a raw MP3 stream with the following optional features:
1604 An ID3v2 metadata header at the beginning (enabled by default). Versions 2.3 and
1605 2.4 are supported, the @code{id3v2_version} private option controls which one is
1606 used (3 or 4). Setting @code{id3v2_version} to 0 disables the ID3v2 header
1609 The muxer supports writing attached pictures (APIC frames) to the ID3v2 header.
1610 The pictures are supplied to the muxer in form of a video stream with a single
1611 packet. There can be any number of those streams, each will correspond to a
1612 single APIC frame. The stream metadata tags @var{title} and @var{comment} map
1613 to APIC @var{description} and @var{picture type} respectively. See
1614 @url{http://id3.org/id3v2.4.0-frames} for allowed picture types.
1616 Note that the APIC frames must be written at the beginning, so the muxer will
1617 buffer the audio frames until it gets all the pictures. It is therefore advised
1618 to provide the pictures as soon as possible to avoid excessive buffering.
1621 A Xing/LAME frame right after the ID3v2 header (if present). It is enabled by
1622 default, but will be written only if the output is seekable. The
1623 @code{write_xing} private option can be used to disable it. The frame contains
1624 various information that may be useful to the decoder, like the audio duration
1628 A legacy ID3v1 tag at the end of the file (disabled by default). It may be
1629 enabled with the @code{write_id3v1} private option, but as its capabilities are
1630 very limited, its usage is not recommended.
1635 Write an mp3 with an ID3v2.3 header and an ID3v1 footer:
1637 ffmpeg -i INPUT -id3v2_version 3 -write_id3v1 1 out.mp3
1640 To attach a picture to an mp3 file select both the audio and the picture stream
1643 ffmpeg -i input.mp3 -i cover.png -c copy -map 0 -map 1
1644 -metadata:s:v title="Album cover" -metadata:s:v comment="Cover (Front)" out.mp3
1647 Write a "clean" MP3 without any extra features:
1649 ffmpeg -i input.wav -write_xing 0 -id3v2_version 0 out.mp3
1654 MPEG transport stream muxer.
1656 This muxer implements ISO 13818-1 and part of ETSI EN 300 468.
1658 The recognized metadata settings in mpegts muxer are @code{service_provider}
1659 and @code{service_name}. If they are not set the default for
1660 @code{service_provider} is @samp{FFmpeg} and the default for
1661 @code{service_name} is @samp{Service01}.
1665 The muxer options are:
1668 @item mpegts_transport_stream_id @var{integer}
1669 Set the @samp{transport_stream_id}. This identifies a transponder in DVB.
1670 Default is @code{0x0001}.
1672 @item mpegts_original_network_id @var{integer}
1673 Set the @samp{original_network_id}. This is unique identifier of a
1674 network in DVB. Its main use is in the unique identification of a service
1675 through the path @samp{Original_Network_ID, Transport_Stream_ID}. Default
1678 @item mpegts_service_id @var{integer}
1679 Set the @samp{service_id}, also known as program in DVB. Default is
1682 @item mpegts_service_type @var{integer}
1683 Set the program @samp{service_type}. Default is @code{digital_tv}.
1684 Accepts the following options:
1687 Any hexadecimal value between @code{0x01} and @code{0xff} as defined in
1692 Digital Radio service.
1695 @item advanced_codec_digital_radio
1696 Advanced Codec Digital Radio service.
1697 @item mpeg2_digital_hdtv
1698 MPEG2 Digital HDTV service.
1699 @item advanced_codec_digital_sdtv
1700 Advanced Codec Digital SDTV service.
1701 @item advanced_codec_digital_hdtv
1702 Advanced Codec Digital HDTV service.
1705 @item mpegts_pmt_start_pid @var{integer}
1706 Set the first PID for PMTs. Default is @code{0x1000}, minimum is @code{0x0020},
1707 maximum is @code{0x1ffa}. This option has no effect in m2ts mode where the PMT
1708 PID is fixed @code{0x0100}.
1710 @item mpegts_start_pid @var{integer}
1711 Set the first PID for elementary streams. Default is @code{0x0100}, minimum is
1712 @code{0x0020}, maximum is @code{0x1ffa}. This option has no effect in m2ts mode
1713 where the elementary stream PIDs are fixed.
1715 @item mpegts_m2ts_mode @var{boolean}
1716 Enable m2ts mode if set to @code{1}. Default value is @code{-1} which
1719 @item muxrate @var{integer}
1720 Set a constant muxrate. Default is VBR.
1722 @item pes_payload_size @var{integer}
1723 Set minimum PES packet payload in bytes. Default is @code{2930}.
1725 @item mpegts_flags @var{flags}
1726 Set mpegts flags. Accepts the following options:
1728 @item resend_headers
1729 Reemit PAT/PMT before writing the next packet.
1731 Use LATM packetization for AAC.
1732 @item pat_pmt_at_frames
1733 Reemit PAT and PMT at each video frame.
1735 Conform to System B (DVB) instead of System A (ATSC).
1736 @item initial_discontinuity
1737 Mark the initial packet of each stream as discontinuity.
1740 @item mpegts_copyts @var{boolean}
1741 Preserve original timestamps, if value is set to @code{1}. Default value
1742 is @code{-1}, which results in shifting timestamps so that they start from 0.
1744 @item omit_video_pes_length @var{boolean}
1745 Omit the PES packet length for video packets. Default is @code{1} (true).
1747 @item pcr_period @var{integer}
1748 Override the default PCR retransmission time in milliseconds. Default is
1749 @code{-1} which means that the PCR interval will be determined automatically:
1750 20 ms is used for CBR streams, the highest multiple of the frame duration which
1751 is less than 100 ms is used for VBR streams.
1753 @item pat_period @var{duration}
1754 Maximum time in seconds between PAT/PMT tables. Default is @code{0.1}.
1756 @item sdt_period @var{duration}
1757 Maximum time in seconds between SDT tables. Default is @code{0.5}.
1759 @item tables_version @var{integer}
1760 Set PAT, PMT and SDT version (default @code{0}, valid values are from 0 to 31, inclusively).
1761 This option allows updating stream structure so that standard consumer may
1762 detect the change. To do so, reopen output @code{AVFormatContext} (in case of API
1763 usage) or restart @command{ffmpeg} instance, cyclically changing
1764 @option{tables_version} value:
1767 ffmpeg -i source1.ts -codec copy -f mpegts -tables_version 0 udp://1.1.1.1:1111
1768 ffmpeg -i source2.ts -codec copy -f mpegts -tables_version 1 udp://1.1.1.1:1111
1770 ffmpeg -i source3.ts -codec copy -f mpegts -tables_version 31 udp://1.1.1.1:1111
1771 ffmpeg -i source1.ts -codec copy -f mpegts -tables_version 0 udp://1.1.1.1:1111
1772 ffmpeg -i source2.ts -codec copy -f mpegts -tables_version 1 udp://1.1.1.1:1111
1780 ffmpeg -i file.mpg -c copy \
1781 -mpegts_original_network_id 0x1122 \
1782 -mpegts_transport_stream_id 0x3344 \
1783 -mpegts_service_id 0x5566 \
1784 -mpegts_pmt_start_pid 0x1500 \
1785 -mpegts_start_pid 0x150 \
1786 -metadata service_provider="Some provider" \
1787 -metadata service_name="Some Channel" \
1791 @section mxf, mxf_d10, mxf_opatom
1797 The muxer options are:
1800 @item store_user_comments @var{bool}
1801 Set if user comments should be stored if available or never.
1802 IRT D-10 does not allow user comments. The default is thus to write them for
1803 mxf and mxf_opatom but not for mxf_d10
1810 This muxer does not generate any output file, it is mainly useful for
1811 testing or benchmarking purposes.
1813 For example to benchmark decoding with @command{ffmpeg} you can use the
1816 ffmpeg -benchmark -i INPUT -f null out.null
1819 Note that the above command does not read or write the @file{out.null}
1820 file, but specifying the output file is required by the @command{ffmpeg}
1823 Alternatively you can write the command as:
1825 ffmpeg -benchmark -i INPUT -f null -
1831 @item -syncpoints @var{flags}
1832 Change the syncpoint usage in nut:
1834 @item @var{default} use the normal low-overhead seeking aids.
1835 @item @var{none} do not use the syncpoints at all, reducing the overhead but making the stream non-seekable;
1836 Use of this option is not recommended, as the resulting files are very damage
1837 sensitive and seeking is not possible. Also in general the overhead from
1838 syncpoints is negligible. Note, -@code{write_index} 0 can be used to disable
1839 all growing data tables, allowing to mux endless streams with limited memory
1840 and without these disadvantages.
1841 @item @var{timestamped} extend the syncpoint with a wallclock field.
1843 The @var{none} and @var{timestamped} flags are experimental.
1844 @item -write_index @var{bool}
1845 Write index at the end, the default is to write an index.
1849 ffmpeg -i INPUT -f_strict experimental -syncpoints none - | processor
1854 Ogg container muxer.
1857 @item -page_duration @var{duration}
1858 Preferred page duration, in microseconds. The muxer will attempt to create
1859 pages that are approximately @var{duration} microseconds long. This allows the
1860 user to compromise between seek granularity and container overhead. The default
1861 is 1 second. A value of 0 will fill all segments, making pages as large as
1862 possible. A value of 1 will effectively use 1 packet-per-page in most
1863 situations, giving a small seek granularity at the cost of additional container
1865 @item -serial_offset @var{value}
1866 Serial value from which to set the streams serial number.
1867 Setting it to different and sufficiently large values ensures that the produced
1868 ogg files can be safely chained.
1873 @section segment, stream_segment, ssegment
1875 Basic stream segmenter.
1877 This muxer outputs streams to a number of separate files of nearly
1878 fixed duration. Output filename pattern can be set in a fashion
1879 similar to @ref{image2}, or by using a @code{strftime} template if
1880 the @option{strftime} option is enabled.
1882 @code{stream_segment} is a variant of the muxer used to write to
1883 streaming output formats, i.e. which do not require global headers,
1884 and is recommended for outputting e.g. to MPEG transport stream segments.
1885 @code{ssegment} is a shorter alias for @code{stream_segment}.
1887 Every segment starts with a keyframe of the selected reference stream,
1888 which is set through the @option{reference_stream} option.
1890 Note that if you want accurate splitting for a video file, you need to
1891 make the input key frames correspond to the exact splitting times
1892 expected by the segmenter, or the segment muxer will start the new
1893 segment with the key frame found next after the specified start
1896 The segment muxer works best with a single constant frame rate video.
1898 Optionally it can generate a list of the created segments, by setting
1899 the option @var{segment_list}. The list type is specified by the
1900 @var{segment_list_type} option. The entry filenames in the segment
1901 list are set by default to the basename of the corresponding segment
1904 See also the @ref{hls} muxer, which provides a more specific
1905 implementation for HLS segmentation.
1909 The segment muxer supports the following options:
1912 @item increment_tc @var{1|0}
1913 if set to @code{1}, increment timecode between each segment
1914 If this is selected, the input need to have
1915 a timecode in the first video stream. Default value is
1918 @item reference_stream @var{specifier}
1919 Set the reference stream, as specified by the string @var{specifier}.
1920 If @var{specifier} is set to @code{auto}, the reference is chosen
1921 automatically. Otherwise it must be a stream specifier (see the ``Stream
1922 specifiers'' chapter in the ffmpeg manual) which specifies the
1923 reference stream. The default value is @code{auto}.
1925 @item segment_format @var{format}
1926 Override the inner container format, by default it is guessed by the filename
1929 @item segment_format_options @var{options_list}
1930 Set output format options using a :-separated list of key=value
1931 parameters. Values containing the @code{:} special character must be
1934 @item segment_list @var{name}
1935 Generate also a listfile named @var{name}. If not specified no
1936 listfile is generated.
1938 @item segment_list_flags @var{flags}
1939 Set flags affecting the segment list generation.
1941 It currently supports the following flags:
1944 Allow caching (only affects M3U8 list files).
1947 Allow live-friendly file generation.
1950 @item segment_list_size @var{size}
1951 Update the list file so that it contains at most @var{size}
1952 segments. If 0 the list file will contain all the segments. Default
1955 @item segment_list_entry_prefix @var{prefix}
1956 Prepend @var{prefix} to each entry. Useful to generate absolute paths.
1957 By default no prefix is applied.
1959 @item segment_list_type @var{type}
1960 Select the listing format.
1962 The following values are recognized:
1965 Generate a flat list for the created segments, one segment per line.
1968 Generate a list for the created segments, one segment per line,
1969 each line matching the format (comma-separated values):
1971 @var{segment_filename},@var{segment_start_time},@var{segment_end_time}
1974 @var{segment_filename} is the name of the output file generated by the
1975 muxer according to the provided pattern. CSV escaping (according to
1976 RFC4180) is applied if required.
1978 @var{segment_start_time} and @var{segment_end_time} specify
1979 the segment start and end time expressed in seconds.
1981 A list file with the suffix @code{".csv"} or @code{".ext"} will
1982 auto-select this format.
1984 @samp{ext} is deprecated in favor or @samp{csv}.
1987 Generate an ffconcat file for the created segments. The resulting file
1988 can be read using the FFmpeg @ref{concat} demuxer.
1990 A list file with the suffix @code{".ffcat"} or @code{".ffconcat"} will
1991 auto-select this format.
1994 Generate an extended M3U8 file, version 3, compliant with
1995 @url{http://tools.ietf.org/id/draft-pantos-http-live-streaming}.
1997 A list file with the suffix @code{".m3u8"} will auto-select this format.
2000 If not specified the type is guessed from the list file name suffix.
2002 @item segment_time @var{time}
2003 Set segment duration to @var{time}, the value must be a duration
2004 specification. Default value is "2". See also the
2005 @option{segment_times} option.
2007 Note that splitting may not be accurate, unless you force the
2008 reference stream key-frames at the given time. See the introductory
2009 notice and the examples below.
2011 @item segment_atclocktime @var{1|0}
2012 If set to "1" split at regular clock time intervals starting from 00:00
2013 o'clock. The @var{time} value specified in @option{segment_time} is
2014 used for setting the length of the splitting interval.
2016 For example with @option{segment_time} set to "900" this makes it possible
2017 to create files at 12:00 o'clock, 12:15, 12:30, etc.
2019 Default value is "0".
2021 @item segment_clocktime_offset @var{duration}
2022 Delay the segment splitting times with the specified duration when using
2023 @option{segment_atclocktime}.
2025 For example with @option{segment_time} set to "900" and
2026 @option{segment_clocktime_offset} set to "300" this makes it possible to
2027 create files at 12:05, 12:20, 12:35, etc.
2029 Default value is "0".
2031 @item segment_clocktime_wrap_duration @var{duration}
2032 Force the segmenter to only start a new segment if a packet reaches the muxer
2033 within the specified duration after the segmenting clock time. This way you
2034 can make the segmenter more resilient to backward local time jumps, such as
2035 leap seconds or transition to standard time from daylight savings time.
2037 Default is the maximum possible duration which means starting a new segment
2038 regardless of the elapsed time since the last clock time.
2040 @item segment_time_delta @var{delta}
2041 Specify the accuracy time when selecting the start time for a
2042 segment, expressed as a duration specification. Default value is "0".
2044 When delta is specified a key-frame will start a new segment if its
2045 PTS satisfies the relation:
2047 PTS >= start_time - time_delta
2050 This option is useful when splitting video content, which is always
2051 split at GOP boundaries, in case a key frame is found just before the
2052 specified split time.
2054 In particular may be used in combination with the @file{ffmpeg} option
2055 @var{force_key_frames}. The key frame times specified by
2056 @var{force_key_frames} may not be set accurately because of rounding
2057 issues, with the consequence that a key frame time may result set just
2058 before the specified time. For constant frame rate videos a value of
2059 1/(2*@var{frame_rate}) should address the worst case mismatch between
2060 the specified time and the time set by @var{force_key_frames}.
2062 @item segment_times @var{times}
2063 Specify a list of split points. @var{times} contains a list of comma
2064 separated duration specifications, in increasing order. See also
2065 the @option{segment_time} option.
2067 @item segment_frames @var{frames}
2068 Specify a list of split video frame numbers. @var{frames} contains a
2069 list of comma separated integer numbers, in increasing order.
2071 This option specifies to start a new segment whenever a reference
2072 stream key frame is found and the sequential number (starting from 0)
2073 of the frame is greater or equal to the next value in the list.
2075 @item segment_wrap @var{limit}
2076 Wrap around segment index once it reaches @var{limit}.
2078 @item segment_start_number @var{number}
2079 Set the sequence number of the first segment. Defaults to @code{0}.
2081 @item strftime @var{1|0}
2082 Use the @code{strftime} function to define the name of the new
2083 segments to write. If this is selected, the output segment name must
2084 contain a @code{strftime} function template. Default value is
2087 @item break_non_keyframes @var{1|0}
2088 If enabled, allow segments to start on frames other than keyframes. This
2089 improves behavior on some players when the time between keyframes is
2090 inconsistent, but may make things worse on others, and can cause some oddities
2091 during seeking. Defaults to @code{0}.
2093 @item reset_timestamps @var{1|0}
2094 Reset timestamps at the beginning of each segment, so that each segment
2095 will start with near-zero timestamps. It is meant to ease the playback
2096 of the generated segments. May not work with some combinations of
2097 muxers/codecs. It is set to @code{0} by default.
2099 @item initial_offset @var{offset}
2100 Specify timestamp offset to apply to the output packet timestamps. The
2101 argument must be a time duration specification, and defaults to 0.
2103 @item write_empty_segments @var{1|0}
2104 If enabled, write an empty segment if there are no packets during the period a
2105 segment would usually span. Otherwise, the segment will be filled with the next
2106 packet written. Defaults to @code{0}.
2109 Make sure to require a closed GOP when encoding and to set the GOP
2110 size to fit your segment time constraint.
2112 @subsection Examples
2116 Remux the content of file @file{in.mkv} to a list of segments
2117 @file{out-000.nut}, @file{out-001.nut}, etc., and write the list of
2118 generated segments to @file{out.list}:
2120 ffmpeg -i in.mkv -codec hevc -flags +cgop -g 60 -map 0 -f segment -segment_list out.list out%03d.nut
2124 Segment input and set output format options for the output segments:
2126 ffmpeg -i in.mkv -f segment -segment_time 10 -segment_format_options movflags=+faststart out%03d.mp4
2130 Segment the input file according to the split points specified by the
2131 @var{segment_times} option:
2133 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
2137 Use the @command{ffmpeg} @option{force_key_frames}
2138 option to force key frames in the input at the specified location, together
2139 with the segment option @option{segment_time_delta} to account for
2140 possible roundings operated when setting key frame times.
2142 ffmpeg -i in.mkv -force_key_frames 1,2,3,5,8,13,21 -codec:v mpeg4 -codec:a pcm_s16le -map 0 \
2143 -f segment -segment_list out.csv -segment_times 1,2,3,5,8,13,21 -segment_time_delta 0.05 out%03d.nut
2145 In order to force key frames on the input file, transcoding is
2149 Segment the input file by splitting the input file according to the
2150 frame numbers sequence specified with the @option{segment_frames} option:
2152 ffmpeg -i in.mkv -codec copy -map 0 -f segment -segment_list out.csv -segment_frames 100,200,300,500,800 out%03d.nut
2156 Convert the @file{in.mkv} to TS segments using the @code{libx264}
2157 and @code{aac} encoders:
2159 ffmpeg -i in.mkv -map 0 -codec:v libx264 -codec:a aac -f ssegment -segment_list out.list out%03d.ts
2163 Segment the input file, and create an M3U8 live playlist (can be used
2164 as live HLS source):
2166 ffmpeg -re -i in.mkv -codec copy -map 0 -f segment -segment_list playlist.m3u8 \
2167 -segment_list_flags +live -segment_time 10 out%03d.mkv
2171 @section smoothstreaming
2173 Smooth Streaming muxer generates a set of files (Manifest, chunks) suitable for serving with conventional web server.
2177 Specify the number of fragments kept in the manifest. Default 0 (keep all).
2179 @item extra_window_size
2180 Specify the number of fragments kept outside of the manifest before removing from disk. Default 5.
2182 @item lookahead_count
2183 Specify the number of lookahead fragments. Default 2.
2185 @item min_frag_duration
2186 Specify the minimum fragment duration (in microseconds). Default 5000000.
2188 @item remove_at_exit
2189 Specify whether to remove all fragments when finished. Default 0 (do not remove).
2196 Per stream hash testing format.
2198 This muxer computes and prints a cryptographic hash of all the input frames,
2199 on a per-stream basis. This can be used for equality checks without having
2200 to do a complete binary comparison.
2202 By default audio frames are converted to signed 16-bit raw audio and
2203 video frames to raw video before computing the hash, but the output
2204 of explicit conversions to other codecs can also be used. Timestamps
2205 are ignored. It uses the SHA-256 cryptographic hash function by default,
2206 but supports several other algorithms.
2208 The output of the muxer consists of one line per stream of the form:
2209 @var{streamindex},@var{streamtype},@var{algo}=@var{hash}, where
2210 @var{streamindex} is the index of the mapped stream, @var{streamtype} is a
2211 single character indicating the type of stream, @var{algo} is a short string
2212 representing the hash function used, and @var{hash} is a hexadecimal number
2213 representing the computed hash.
2216 @item hash @var{algorithm}
2217 Use the cryptographic hash function specified by the string @var{algorithm}.
2218 Supported values include @code{MD5}, @code{murmur3}, @code{RIPEMD128},
2219 @code{RIPEMD160}, @code{RIPEMD256}, @code{RIPEMD320}, @code{SHA160},
2220 @code{SHA224}, @code{SHA256} (default), @code{SHA512/224}, @code{SHA512/256},
2221 @code{SHA384}, @code{SHA512}, @code{CRC32} and @code{adler32}.
2225 @subsection Examples
2227 To compute the SHA-256 hash of the input converted to raw audio and
2228 video, and store it in the file @file{out.sha256}:
2230 ffmpeg -i INPUT -f streamhash out.sha256
2233 To print an MD5 hash to stdout use the command:
2235 ffmpeg -i INPUT -f streamhash -hash md5 -
2238 See also the @ref{hash} and @ref{framehash} muxers.
2243 The fifo pseudo-muxer allows the separation of encoding and muxing by using
2244 first-in-first-out queue and running the actual muxer in a separate thread. This
2245 is especially useful in combination with the @ref{tee} muxer and can be used to
2246 send data to several destinations with different reliability/writing speed/latency.
2248 API users should be aware that callback functions (interrupt_callback,
2249 io_open and io_close) used within its AVFormatContext must be thread-safe.
2251 The behavior of the fifo muxer if the queue fills up or if the output fails is
2257 output can be transparently restarted with configurable delay between retries
2258 based on real time or time of the processed stream.
2261 encoding can be blocked during temporary failure, or continue transparently
2262 dropping packets in case fifo queue fills up.
2269 Specify the format name. Useful if it cannot be guessed from the
2273 Specify size of the queue (number of packets). Default value is 60.
2276 Specify format options for the underlying muxer. Muxer options can be specified
2277 as a list of @var{key}=@var{value} pairs separated by ':'.
2279 @item drop_pkts_on_overflow @var{bool}
2280 If set to 1 (true), in case the fifo queue fills up, packets will be dropped
2281 rather than blocking the encoder. This makes it possible to continue streaming without
2282 delaying the input, at the cost of omitting part of the stream. By default
2283 this option is set to 0 (false), so in such cases the encoder will be blocked
2284 until the muxer processes some of the packets and none of them is lost.
2286 @item attempt_recovery @var{bool}
2287 If failure occurs, attempt to recover the output. This is especially useful
2288 when used with network output, since it makes it possible to restart streaming transparently.
2289 By default this option is set to 0 (false).
2291 @item max_recovery_attempts
2292 Sets maximum number of successive unsuccessful recovery attempts after which
2293 the output fails permanently. By default this option is set to 0 (unlimited).
2295 @item recovery_wait_time @var{duration}
2296 Waiting time before the next recovery attempt after previous unsuccessful
2297 recovery attempt. Default value is 5 seconds.
2299 @item recovery_wait_streamtime @var{bool}
2300 If set to 0 (false), the real time is used when waiting for the recovery
2301 attempt (i.e. the recovery will be attempted after at least
2302 recovery_wait_time seconds).
2303 If set to 1 (true), the time of the processed stream is taken into account
2304 instead (i.e. the recovery will be attempted after at least @var{recovery_wait_time}
2305 seconds of the stream is omitted).
2306 By default, this option is set to 0 (false).
2308 @item recover_any_error @var{bool}
2309 If set to 1 (true), recovery will be attempted regardless of type of the error
2310 causing the failure. By default this option is set to 0 (false) and in case of
2311 certain (usually permanent) errors the recovery is not attempted even when
2312 @var{attempt_recovery} is set to 1.
2314 @item restart_with_keyframe @var{bool}
2315 Specify whether to wait for the keyframe after recovering from
2316 queue overflow or failure. This option is set to 0 (false) by default.
2318 @item timeshift @var{duration}
2319 Buffer the specified amount of packets and delay writing the output. Note that
2320 @var{queue_size} must be big enough to store the packets for timeshift. At the
2321 end of the input the fifo buffer is flushed at realtime speed.
2325 @subsection Examples
2330 Stream something to rtmp server, continue processing the stream at real-time
2331 rate even in case of temporary failure (network outage) and attempt to recover
2332 streaming every second indefinitely.
2334 ffmpeg -re -i ... -c:v libx264 -c:a aac -f fifo -fifo_format flv -map 0:v -map 0:a
2335 -drop_pkts_on_overflow 1 -attempt_recovery 1 -recovery_wait_time 1 rtmp://example.com/live/stream_name
2343 The tee muxer can be used to write the same data to several outputs, such as files or streams.
2344 It can be used, for example, to stream a video over a network and save it to disk at the same time.
2346 It is different from specifying several outputs to the @command{ffmpeg}
2347 command-line tool. With the tee muxer, the audio and video data will be encoded only once.
2348 With conventional multiple outputs, multiple encoding operations in parallel are initiated,
2349 which can be a very expensive process. The tee muxer is not useful when using the libavformat API
2350 directly because it is then possible to feed the same packets to several muxers directly.
2352 Since the tee muxer does not represent any particular output format, ffmpeg cannot auto-select
2353 output streams. So all streams intended for output must be specified using @code{-map}. See
2356 Some encoders may need different options depending on the output format;
2357 the auto-detection of this can not work with the tee muxer, so they need to be explicitly specified.
2358 The main example is the @option{global_header} flag.
2360 The slave outputs are specified in the file name given to the muxer,
2361 separated by '|'. If any of the slave name contains the '|' separator,
2362 leading or trailing spaces or any special character, those must be
2363 escaped (see @ref{quoting_and_escaping,,the "Quoting and escaping"
2364 section in the ffmpeg-utils(1) manual,ffmpeg-utils}).
2370 @item use_fifo @var{bool}
2371 If set to 1, slave outputs will be processed in separate threads using the @ref{fifo}
2372 muxer. This allows to compensate for different speed/latency/reliability of
2373 outputs and setup transparent recovery. By default this feature is turned off.
2376 Options to pass to fifo pseudo-muxer instances. See @ref{fifo}.
2380 Muxer options can be specified for each slave by prepending them as a list of
2381 @var{key}=@var{value} pairs separated by ':', between square brackets. If
2382 the options values contain a special character or the ':' separator, they
2383 must be escaped; note that this is a second level escaping.
2385 The following special options are also recognized:
2388 Specify the format name. Required if it cannot be guessed from the
2391 @item bsfs[/@var{spec}]
2392 Specify a list of bitstream filters to apply to the specified
2395 It is possible to specify to which streams a given bitstream filter
2396 applies, by appending a stream specifier to the option separated by
2397 @code{/}. @var{spec} must be a stream specifier (see @ref{Format
2398 stream specifiers}).
2400 If the stream specifier is not specified, the bitstream filters will be
2401 applied to all streams in the output. This will cause that output operation
2402 to fail if the output contains streams to which the bitstream filter cannot
2403 be applied e.g. @code{h264_mp4toannexb} being applied to an output containing an audio stream.
2405 Options for a bitstream filter must be specified in the form of @code{opt=value}.
2407 Several bitstream filters can be specified, separated by ",".
2409 @item use_fifo @var{bool}
2410 This allows to override tee muxer use_fifo option for individual slave muxer.
2413 This allows to override tee muxer fifo_options for individual slave muxer.
2417 Select the streams that should be mapped to the slave output,
2418 specified by a stream specifier. If not specified, this defaults to
2419 all the mapped streams. This will cause that output operation to fail
2420 if the output format does not accept all mapped streams.
2422 You may use multiple stream specifiers separated by commas (@code{,}) e.g.: @code{a:0,v}
2425 Specify behaviour on output failure. This can be set to either @code{abort} (which is
2426 default) or @code{ignore}. @code{abort} will cause whole process to fail in case of failure
2427 on this slave output. @code{ignore} will ignore failure on this output, so other outputs
2428 will continue without being affected.
2431 @subsection Examples
2435 Encode something and both archive it in a WebM file and stream it
2436 as MPEG-TS over UDP:
2438 ffmpeg -i ... -c:v libx264 -c:a mp2 -f tee -map 0:v -map 0:a
2439 "archive-20121107.mkv|[f=mpegts]udp://10.0.1.255:1234/"
2443 As above, but continue streaming even if output to local file fails
2444 (for example local drive fills up):
2446 ffmpeg -i ... -c:v libx264 -c:a mp2 -f tee -map 0:v -map 0:a
2447 "[onfail=ignore]archive-20121107.mkv|[f=mpegts]udp://10.0.1.255:1234/"
2451 Use @command{ffmpeg} to encode the input, and send the output
2452 to three different destinations. The @code{dump_extra} bitstream
2453 filter is used to add extradata information to all the output video
2454 keyframes packets, as requested by the MPEG-TS format. The select
2455 option is applied to @file{out.aac} in order to make it contain only
2458 ffmpeg -i ... -map 0 -flags +global_header -c:v libx264 -c:a aac
2459 -f tee "[bsfs/v=dump_extra=freq=keyframe]out.ts|[movflags=+faststart]out.mp4|[select=a]out.aac"
2463 As above, but select only stream @code{a:1} for the audio output. Note
2464 that a second level escaping must be performed, as ":" is a special
2465 character used to separate options.
2467 ffmpeg -i ... -map 0 -flags +global_header -c:v libx264 -c:a aac
2468 -f tee "[bsfs/v=dump_extra=freq=keyframe]out.ts|[movflags=+faststart]out.mp4|[select=\'a:1\']out.aac"
2472 @section webm_dash_manifest
2474 WebM DASH Manifest muxer.
2476 This muxer implements the WebM DASH Manifest specification to generate the DASH
2477 manifest XML. It also supports manifest generation for DASH live streams.
2479 For more information see:
2483 WebM DASH Specification: @url{https://sites.google.com/a/webmproject.org/wiki/adaptive-streaming/webm-dash-specification}
2485 ISO DASH Specification: @url{http://standards.iso.org/ittf/PubliclyAvailableStandards/c065274_ISO_IEC_23009-1_2014.zip}
2490 This muxer supports the following options:
2493 @item adaptation_sets
2494 This option has the following syntax: "id=x,streams=a,b,c id=y,streams=d,e" where x and y are the
2495 unique identifiers of the adaptation sets and a,b,c,d and e are the indices of the corresponding
2496 audio and video streams. Any number of adaptation sets can be added using this option.
2499 Set this to 1 to create a live stream DASH Manifest. Default: 0.
2501 @item chunk_start_index
2502 Start index of the first chunk. This will go in the @samp{startNumber} attribute
2503 of the @samp{SegmentTemplate} element in the manifest. Default: 0.
2505 @item chunk_duration_ms
2506 Duration of each chunk in milliseconds. This will go in the @samp{duration}
2507 attribute of the @samp{SegmentTemplate} element in the manifest. Default: 1000.
2509 @item utc_timing_url
2510 URL of the page that will return the UTC timestamp in ISO format. This will go
2511 in the @samp{value} attribute of the @samp{UTCTiming} element in the manifest.
2514 @item time_shift_buffer_depth
2515 Smallest time (in seconds) shifting buffer for which any Representation is
2516 guaranteed to be available. This will go in the @samp{timeShiftBufferDepth}
2517 attribute of the @samp{MPD} element. Default: 60.
2519 @item minimum_update_period
2520 Minimum update period (in seconds) of the manifest. This will go in the
2521 @samp{minimumUpdatePeriod} attribute of the @samp{MPD} element. Default: 0.
2527 ffmpeg -f webm_dash_manifest -i video1.webm \
2528 -f webm_dash_manifest -i video2.webm \
2529 -f webm_dash_manifest -i audio1.webm \
2530 -f webm_dash_manifest -i audio2.webm \
2531 -map 0 -map 1 -map 2 -map 3 \
2533 -f webm_dash_manifest \
2534 -adaptation_sets "id=0,streams=0,1 id=1,streams=2,3" \
2540 WebM Live Chunk Muxer.
2542 This muxer writes out WebM headers and chunks as separate files which can be
2543 consumed by clients that support WebM Live streams via DASH.
2547 This muxer supports the following options:
2550 @item chunk_start_index
2551 Index of the first chunk (defaults to 0).
2554 Filename of the header where the initialization data will be written.
2556 @item audio_chunk_duration
2557 Duration of each audio chunk in milliseconds (defaults to 5000).
2562 ffmpeg -f v4l2 -i /dev/video0 \
2566 -s 640x360 -keyint_min 30 -g 30 \
2568 -header webm_live_video_360.hdr \
2569 -chunk_start_index 1 \
2570 webm_live_video_360_%d.chk \
2575 -header webm_live_audio_128.hdr \
2576 -chunk_start_index 1 \
2577 -audio_chunk_duration 1000 \
2578 webm_live_audio_128_%d.chk