ffmpeg | branch: master | James Almer <jamr...@gmail.com> | Sat Nov 11 23:47:50 2017 -0300| [27aa69896bd6a816026f0fd57b12ad1fc147ab65] | committer: James Almer
Merge commit '0e702124ee149593168cbbb7b30376249a64ae66' * commit '0e702124ee149593168cbbb7b30376249a64ae66': doc: Provide better examples for hls and segment muxing Merged-by: James Almer <jamr...@gmail.com> > http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=27aa69896bd6a816026f0fd57b12ad1fc147ab65 --- doc/muxers.texi | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/doc/muxers.texi b/doc/muxers.texi index 91bbe673c5..43f3776b13 100644 --- a/doc/muxers.texi +++ b/doc/muxers.texi @@ -468,9 +468,12 @@ By default, the muxer creates a file for each segment produced. These files have the same name as the playlist, followed by a sequential number and a .ts extension. +Make sure to require a closed GOP when encoding and to set the GOP +size to fit your segment time constraint. + For example, to convert an input file with @command{ffmpeg}: @example -ffmpeg -i in.nut out.m3u8 +ffmpeg -i in.mkv -c:v h264 -flags +cgop -g 30 -hls_time 1 out.m3u8 @end example This example will produce the playlist, @file{out.m3u8}, and segment files: @file{out0.ts}, @file{out1.ts}, @file{out2.ts}, etc. @@ -1649,6 +1652,9 @@ segment would usually span. Otherwise, the segment will be filled with the next packet written. Defaults to @code{0}. @end table +Make sure to require a closed GOP when encoding and to set the GOP +size to fit your segment time constraint. + @subsection Examples @itemize @@ -1657,7 +1663,7 @@ Remux the content of file @file{in.mkv} to a list of segments @file{out-000.nut}, @file{out-001.nut}, etc., and write the list of generated segments to @file{out.list}: @example -ffmpeg -i in.mkv -codec copy -map 0 -f segment -segment_list out.list out%03d.nut +ffmpeg -i in.mkv -codec hevc -flags +cgop -g 60 -map 0 -f segment -segment_list out.list out%03d.nut @end example @item ====================================================================== diff --cc doc/muxers.texi index 91bbe673c5,8c34322e79..43f3776b13 --- a/doc/muxers.texi +++ b/doc/muxers.texi @@@ -459,206 -156,37 +459,209 @@@ See also the @ref{framehash} muxer @section hls Apple HTTP Live Streaming muxer that segments MPEG-TS according to -the HTTP Live Streaming specification. +the HTTP Live Streaming (HLS) specification. -It creates a playlist file and numbered segment files. The output -filename specifies the playlist filename; the segment filenames -receive the same basename as the playlist, a sequential number and -a .ts extension. +It creates a playlist file, and one or more segment files. The output filename +specifies the playlist filename. + +By default, the muxer creates a file for each segment produced. These files +have the same name as the playlist, followed by a sequential number and a +.ts extension. + Make sure to require a closed GOP when encoding and to set the GOP + size to fit your segment time constraint. + +For example, to convert an input file with @command{ffmpeg}: @example - ffmpeg -i in.nut out.m3u8 -avconv -i in.mkv -c:v h264 -flags +cgop -g 30 -hls_time 1 out.m3u8 ++ffmpeg -i in.mkv -c:v h264 -flags +cgop -g 30 -hls_time 1 out.m3u8 @end example +This example will produce the playlist, @file{out.m3u8}, and segment files: +@file{out0.ts}, @file{out1.ts}, @file{out2.ts}, etc. + +See also the @ref{segment} muxer, which provides a more generic and +flexible implementation of a segmenter, and can be used to perform HLS +segmentation. + +@subsection Options + +This muxer supports the following options: @table @option -@item -hls_time @var{seconds} -Set the segment length in seconds. -@item -hls_list_size @var{size} -Set the maximum number of playlist entries. -@item -hls_wrap @var{wrap} -Set the number after which index wraps. -@item -start_number @var{number} -Start the sequence from @var{number}. -@item -hls_base_url @var{baseurl} +@item hls_init_time @var{seconds} +Set the initial target segment length in seconds. Default value is @var{0}. +Segment will be cut on the next key frame after this time has passed on the first m3u8 list. +After the initial playlist is filled @command{ffmpeg} will cut segments +at duration equal to @code{hls_time} + +@item hls_time @var{seconds} +Set the target segment length in seconds. Default value is 2. +Segment will be cut on the next key frame after this time has passed. + +@item hls_list_size @var{size} +Set the maximum number of playlist entries. If set to 0 the list file +will contain all the segments. Default value is 5. + +@item hls_ts_options @var{options_list} +Set output format options using a :-separated list of key=value +parameters. Values containing @code{:} special characters must be +escaped. + +@item hls_wrap @var{wrap} +This is a deprecated option, you can use @code{hls_list_size} +and @code{hls_flags delete_segments} instead it + +This option is useful to avoid to fill the disk with many segment +files, and limits the maximum number of segment files written to disk +to @var{wrap}. + + +@item hls_start_number_source +Start the playlist sequence number (@code{#EXT-X-MEDIA-SEQUENCE}) according to the specified source. +Unless @code{hls_flags single_file} is set, it also specifies source of starting sequence numbers of +segment and subtitle filenames. In any case, if @code{hls_flags append_list} +is set and read playlist sequence number is greater than the specified start sequence number, +then that value will be used as start value. + +It accepts the following values: + +@table @option + +@item generic (default) +Set the starting sequence numbers according to @var{start_number} option value. + +@item epoch +The start number will be the seconds since epoch (1970-01-01 00:00:00) + +@item datetime +The start number will be based on the current date/time as YYYYmmddHHMMSS. e.g. 20161231235759. + +@end table + +@item start_number @var{number} +Start the playlist sequence number (@code{#EXT-X-MEDIA-SEQUENCE}) from the specified @var{number} +when @var{hls_start_number_source} value is @var{generic}. (This is the default case.) +Unless @code{hls_flags single_file} is set, it also specifies starting sequence numbers of segment and subtitle filenames. +Default value is 0. + +@item hls_allow_cache @var{allowcache} +Explicitly set whether the client MAY (1) or MUST NOT (0) cache media segments. + +@item hls_base_url @var{baseurl} Append @var{baseurl} to every entry in the playlist. Useful to generate playlists with absolute paths. -@item -hls_allow_cache @var{allowcache} -Explicitly set whether the client MAY (1) or MUST NOT (0) cache media segments -@item -hls_version @var{version} -Set the protocol version. Enables or disables version-specific features -such as the integer (version 2) or decimal EXTINF values (version 3). + +Note that the playlist sequence number must be unique for each segment +and it is not to be confused with the segment filename sequence number +which can be cyclic, for example if the @option{wrap} option is +specified. + +@item hls_segment_filename @var{filename} +Set the segment filename. Unless @code{hls_flags single_file} is set, +@var{filename} is used as a string format with the segment number: +@example +ffmpeg -i in.nut -hls_segment_filename 'file%03d.ts' out.m3u8 +@end example +This example will produce the playlist, @file{out.m3u8}, and segment files: +@file{file000.ts}, @file{file001.ts}, @file{file002.ts}, etc. + +@var{filename} may contain full path or relative path specification, +but only the file name part without any path info will be contained in the m3u8 segment list. +Should a relative path be specified, the path of the created segment +files will be relative to the current working directory. +When use_localtime_mkdir is set, the whole expanded value of @var{filename} will be written into the m3u8 segment list. + + +@item use_localtime +Use strftime() on @var{filename} to expand the segment filename with localtime. +The segment number is also available in this mode, but to use it, you need to specify second_level_segment_index +hls_flag and %%d will be the specifier. +@example +ffmpeg -i in.nut -use_localtime 1 -hls_segment_filename 'file-%Y%m%d-%s.ts' out.m3u8 +@end example +This example will produce the playlist, @file{out.m3u8}, and segment files: +@file{file-20160215-1455569023.ts}, @file{file-20160215-1455569024.ts}, etc. +Note: On some systems/environments, the @code{%s} specifier is not available. See + @code{strftime()} documentation. +@example +ffmpeg -i in.nut -use_localtime 1 -hls_flags second_level_segment_index -hls_segment_filename 'file-%Y%m%d-%%04d.ts' out.m3u8 +@end example +This example will produce the playlist, @file{out.m3u8}, and segment files: +@file{file-20160215-0001.ts}, @file{file-20160215-0002.ts}, etc. + +@item use_localtime_mkdir +Used together with -use_localtime, it will create all subdirectories which +is expanded in @var{filename}. +@example +ffmpeg -i in.nut -use_localtime 1 -use_localtime_mkdir 1 -hls_segment_filename '%Y%m%d/file-%Y%m%d-%s.ts' out.m3u8 +@end example +This example will create a directory 201560215 (if it does not exist), and then +produce the playlist, @file{out.m3u8}, and segment files: +@file{20160215/file-20160215-1455569023.ts}, @file{20160215/file-20160215-1455569024.ts}, etc. + +@example +ffmpeg -i in.nut -use_localtime 1 -use_localtime_mkdir 1 -hls_segment_filename '%Y/%m/%d/file-%Y%m%d-%s.ts' out.m3u8 +@end example +This example will create a directory hierarchy 2016/02/15 (if any of them do not exist), and then +produce the playlist, @file{out.m3u8}, and segment files: +@file{2016/02/15/file-20160215-1455569023.ts}, @file{2016/02/15/file-20160215-1455569024.ts}, etc. + + +@item hls_key_info_file @var{key_info_file} +Use the information in @var{key_info_file} for segment encryption. The first +line of @var{key_info_file} specifies the key URI written to the playlist. The +key URL is used to access the encryption key during playback. The second line +specifies the path to the key file used to obtain the key during the encryption +process. The key file is read as a single packed array of 16 octets in binary +format. The optional third line specifies the initialization vector (IV) as a +hexadecimal string to be used instead of the segment sequence number (default) +for encryption. Changes to @var{key_info_file} will result in segment +encryption with the new key/IV and an entry in the playlist for the new key +URI/IV if @code{hls_flags periodic_rekey} is enabled. + +Key info file format: +@example +@var{key URI} +@var{key file path} +@var{IV} (optional) +@end example + +Example key URIs: +@example +http://server/file.key +/path/to/file.key +file.key +@end example + +Example key file paths: +@example +file.key +/path/to/file.key +@end example + +Example IV: +@example +0123456789ABCDEF0123456789ABCDEF +@end example + +Key info file example: +@example +http://server/file.key +/path/to/file.key +0123456789ABCDEF0123456789ABCDEF +@end example + +Example shell script: +@example +#!/bin/sh +BASE_URL=$@{1:-'.'@} +openssl rand 16 > file.key +echo $BASE_URL/file.key > file.keyinfo +echo file.key >> file.keyinfo +echo $(openssl rand -hex 16) >> file.keyinfo +ffmpeg -f lavfi -re -i testsrc -c:v h264 -hls_flags delete_segments \ + -hls_key_info_file file.keyinfo out.m3u8 +@end example + @item -hls_enc @var{enc} Enable (1) or disable (0) the AES128 encryption. When enabled every segment generated is encrypted and the encryption key @@@ -1468,589 -610,29 +1471,592 @@@ reference stream. The default value is @item segment_format @var{format} Override the inner container format, by default it is guessed by the filename extension. -@item segment_time @var{t} -Set segment duration to @var{t} seconds. + +@item segment_format_options @var{options_list} +Set output format options using a :-separated list of key=value +parameters. Values containing the @code{:} special character must be +escaped. + @item segment_list @var{name} -Generate also a listfile named @var{name}. -@item segment_list_type @var{type} -Select the listing format. -@table @option -@item @var{flat} use a simple flat list of entries. -@item @var{hls} use a m3u8-like structure. +Generate also a listfile named @var{name}. If not specified no +listfile is generated. + +@item segment_list_flags @var{flags} +Set flags affecting the segment list generation. + +It currently supports the following flags: +@table @samp +@item cache +Allow caching (only affects M3U8 list files). + +@item live +Allow live-friendly file generation. @end table + @item segment_list_size @var{size} -Overwrite the listfile once it reaches @var{size} entries. +Update the list file so that it contains at most @var{size} +segments. If 0 the list file will contain all the segments. Default +value is 0. + @item segment_list_entry_prefix @var{prefix} Prepend @var{prefix} to each entry. Useful to generate absolute paths. +By default no prefix is applied. + +@item segment_list_type @var{type} +Select the listing format. + +The following values are recognized: +@table @samp +@item flat +Generate a flat list for the created segments, one segment per line. + +@item csv, ext +Generate a list for the created segments, one segment per line, +each line matching the format (comma-separated values): +@example +@var{segment_filename},@var{segment_start_time},@var{segment_end_time} +@end example + +@var{segment_filename} is the name of the output file generated by the +muxer according to the provided pattern. CSV escaping (according to +RFC4180) is applied if required. + +@var{segment_start_time} and @var{segment_end_time} specify +the segment start and end time expressed in seconds. + +A list file with the suffix @code{".csv"} or @code{".ext"} will +auto-select this format. + +@samp{ext} is deprecated in favor or @samp{csv}. + +@item ffconcat +Generate an ffconcat file for the created segments. The resulting file +can be read using the FFmpeg @ref{concat} demuxer. + +A list file with the suffix @code{".ffcat"} or @code{".ffconcat"} will +auto-select this format. + +@item m3u8 +Generate an extended M3U8 file, version 3, compliant with +@url{http://tools.ietf.org/id/draft-pantos-http-live-streaming}. + +A list file with the suffix @code{".m3u8"} will auto-select this format. +@end table + +If not specified the type is guessed from the list file name suffix. + +@item segment_time @var{time} +Set segment duration to @var{time}, the value must be a duration +specification. Default value is "2". See also the +@option{segment_times} option. + +Note that splitting may not be accurate, unless you force the +reference stream key-frames at the given time. See the introductory +notice and the examples below. + +@item segment_atclocktime @var{1|0} +If set to "1" split at regular clock time intervals starting from 00:00 +o'clock. The @var{time} value specified in @option{segment_time} is +used for setting the length of the splitting interval. + +For example with @option{segment_time} set to "900" this makes it possible +to create files at 12:00 o'clock, 12:15, 12:30, etc. + +Default value is "0". + +@item segment_clocktime_offset @var{duration} +Delay the segment splitting times with the specified duration when using +@option{segment_atclocktime}. + +For example with @option{segment_time} set to "900" and +@option{segment_clocktime_offset} set to "300" this makes it possible to +create files at 12:05, 12:20, 12:35, etc. + +Default value is "0". + +@item segment_clocktime_wrap_duration @var{duration} +Force the segmenter to only start a new segment if a packet reaches the muxer +within the specified duration after the segmenting clock time. This way you +can make the segmenter more resilient to backward local time jumps, such as +leap seconds or transition to standard time from daylight savings time. + +Default is the maximum possible duration which means starting a new segment +regardless of the elapsed time since the last clock time. + +@item segment_time_delta @var{delta} +Specify the accuracy time when selecting the start time for a +segment, expressed as a duration specification. Default value is "0". + +When delta is specified a key-frame will start a new segment if its +PTS satisfies the relation: +@example +PTS >= start_time - time_delta +@end example + +This option is useful when splitting video content, which is always +split at GOP boundaries, in case a key frame is found just before the +specified split time. + +In particular may be used in combination with the @file{ffmpeg} option +@var{force_key_frames}. The key frame times specified by +@var{force_key_frames} may not be set accurately because of rounding +issues, with the consequence that a key frame time may result set just +before the specified time. For constant frame rate videos a value of +1/(2*@var{frame_rate}) should address the worst case mismatch between +the specified time and the time set by @var{force_key_frames}. + +@item segment_times @var{times} +Specify a list of split points. @var{times} contains a list of comma +separated duration specifications, in increasing order. See also +the @option{segment_time} option. + +@item segment_frames @var{frames} +Specify a list of split video frame numbers. @var{frames} contains a +list of comma separated integer numbers, in increasing order. + +This option specifies to start a new segment whenever a reference +stream key frame is found and the sequential number (starting from 0) +of the frame is greater or equal to the next value in the list. + @item segment_wrap @var{limit} Wrap around segment index once it reaches @var{limit}. + +@item segment_start_number @var{number} +Set the sequence number of the first segment. Defaults to @code{0}. + +@item strftime @var{1|0} +Use the @code{strftime} function to define the name of the new +segments to write. If this is selected, the output segment name must +contain a @code{strftime} function template. Default value is +@code{0}. + +@item break_non_keyframes @var{1|0} +If enabled, allow segments to start on frames other than keyframes. This +improves behavior on some players when the time between keyframes is +inconsistent, but may make things worse on others, and can cause some oddities +during seeking. Defaults to @code{0}. + +@item reset_timestamps @var{1|0} +Reset timestamps at the beginning of each segment, so that each segment +will start with near-zero timestamps. It is meant to ease the playback +of the generated segments. May not work with some combinations of +muxers/codecs. It is set to @code{0} by default. + +@item initial_offset @var{offset} +Specify timestamp offset to apply to the output packet timestamps. The +argument must be a time duration specification, and defaults to 0. + +@item write_empty_segments @var{1|0} +If enabled, write an empty segment if there are no packets during the period a +segment would usually span. Otherwise, the segment will be filled with the next +packet written. Defaults to @code{0}. @end table + Make sure to require a closed GOP when encoding and to set the GOP + size to fit your segment time constraint. + +@subsection Examples + +@itemize +@item +Remux the content of file @file{in.mkv} to a list of segments +@file{out-000.nut}, @file{out-001.nut}, etc., and write the list of +generated segments to @file{out.list}: +@example - ffmpeg -i in.mkv -codec copy -map 0 -f segment -segment_list out.list out%03d.nut ++ffmpeg -i in.mkv -codec hevc -flags +cgop -g 60 -map 0 -f segment -segment_list out.list out%03d.nut +@end example + +@item +Segment input and set output format options for the output segments: +@example +ffmpeg -i in.mkv -f segment -segment_time 10 -segment_format_options movflags=+faststart out%03d.mp4 +@end example + +@item +Segment the input file according to the split points specified by the +@var{segment_times} option: +@example +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 +@end example + +@item +Use the @command{ffmpeg} @option{force_key_frames} +option to force key frames in the input at the specified location, together +with the segment option @option{segment_time_delta} to account for +possible roundings operated when setting key frame times. +@example +ffmpeg -i in.mkv -force_key_frames 1,2,3,5,8,13,21 -codec:v mpeg4 -codec:a pcm_s16le -map 0 \ +-f segment -segment_list out.csv -segment_times 1,2,3,5,8,13,21 -segment_time_delta 0.05 out%03d.nut +@end example +In order to force key frames on the input file, transcoding is +required. + +@item +Segment the input file by splitting the input file according to the +frame numbers sequence specified with the @option{segment_frames} option: +@example +ffmpeg -i in.mkv -codec copy -map 0 -f segment -segment_list out.csv -segment_frames 100,200,300,500,800 out%03d.nut +@end example + +@item +Convert the @file{in.mkv} to TS segments using the @code{libx264} +and @code{aac} encoders: +@example +ffmpeg -i in.mkv -map 0 -codec:v libx264 -codec:a aac -f ssegment -segment_list out.list out%03d.ts +@end example + +@item +Segment the input file, and create an M3U8 live playlist (can be used +as live HLS source): +@example +ffmpeg -re -i in.mkv -codec copy -map 0 -f segment -segment_list playlist.m3u8 \ +-segment_list_flags +live -segment_time 10 out%03d.mkv +@end example +@end itemize + +@section smoothstreaming + +Smooth Streaming muxer generates a set of files (Manifest, chunks) suitable for serving with conventional web server. + +@table @option +@item window_size +Specify the number of fragments kept in the manifest. Default 0 (keep all). + +@item extra_window_size +Specify the number of fragments kept outside of the manifest before removing from disk. Default 5. + +@item lookahead_count +Specify the number of lookahead fragments. Default 2. + +@item min_frag_duration +Specify the minimum fragment duration (in microseconds). Default 5000000. + +@item remove_at_exit +Specify whether to remove all fragments when finished. Default 0 (do not remove). + +@end table + +@anchor{fifo} +@section fifo + +The fifo pseudo-muxer allows the separation of encoding and muxing by using +first-in-first-out queue and running the actual muxer in a separate thread. This +is especially useful in combination with the @ref{tee} muxer and can be used to +send data to several destinations with different reliability/writing speed/latency. + +API users should be aware that callback functions (interrupt_callback, +io_open and io_close) used within its AVFormatContext must be thread-safe. + +The behavior of the fifo muxer if the queue fills up or if the output fails is +selectable, + +@itemize @bullet + +@item +output can be transparently restarted with configurable delay between retries +based on real time or time of the processed stream. + +@item +encoding can be blocked during temporary failure, or continue transparently +dropping packets in case fifo queue fills up. + +@end itemize + +@table @option + +@item fifo_format +Specify the format name. Useful if it cannot be guessed from the +output name suffix. + +@item queue_size +Specify size of the queue (number of packets). Default value is 60. + +@item format_opts +Specify format options for the underlying muxer. Muxer options can be specified +as a list of @var{key}=@var{value} pairs separated by ':'. + +@item drop_pkts_on_overflow @var{bool} +If set to 1 (true), in case the fifo queue fills up, packets will be dropped +rather than blocking the encoder. This makes it possible to continue streaming without +delaying the input, at the cost of omitting part of the stream. By default +this option is set to 0 (false), so in such cases the encoder will be blocked +until the muxer processes some of the packets and none of them is lost. + +@item attempt_recovery @var{bool} +If failure occurs, attempt to recover the output. This is especially useful +when used with network output, since it makes it possible to restart streaming transparently. +By default this option is set to 0 (false). + +@item max_recovery_attempts +Sets maximum number of successive unsuccessful recovery attempts after which +the output fails permanently. By default this option is set to 0 (unlimited). + +@item recovery_wait_time @var{duration} +Waiting time before the next recovery attempt after previous unsuccessful +recovery attempt. Default value is 5 seconds. + +@item recovery_wait_streamtime @var{bool} +If set to 0 (false), the real time is used when waiting for the recovery +attempt (i.e. the recovery will be attempted after at least +recovery_wait_time seconds). +If set to 1 (true), the time of the processed stream is taken into account +instead (i.e. the recovery will be attempted after at least @var{recovery_wait_time} +seconds of the stream is omitted). +By default, this option is set to 0 (false). + +@item recover_any_error @var{bool} +If set to 1 (true), recovery will be attempted regardless of type of the error +causing the failure. By default this option is set to 0 (false) and in case of +certain (usually permanent) errors the recovery is not attempted even when +@var{attempt_recovery} is set to 1. + +@item restart_with_keyframe @var{bool} +Specify whether to wait for the keyframe after recovering from +queue overflow or failure. This option is set to 0 (false) by default. + +@end table + +@subsection Examples + +@itemize + +@item +Stream something to rtmp server, continue processing the stream at real-time +rate even in case of temporary failure (network outage) and attempt to recover +streaming every second indefinitely. +@example +ffmpeg -re -i ... -c:v libx264 -c:a aac -f fifo -fifo_format flv -map 0:v -map 0:a + -drop_pkts_on_overflow 1 -attempt_recovery 1 -recovery_wait_time 1 rtmp://example.com/live/stream_name +@end example + +@end itemize + +@anchor{tee} +@section tee + +The tee muxer can be used to write the same data to several files or any +other kind of muxer. It can be used, for example, to both stream a video to +the network and save it to disk at the same time. + +It is different from specifying several outputs to the @command{ffmpeg} +command-line tool because the audio and video data will be encoded only once +with the tee muxer; encoding can be a very expensive process. It is not +useful when using the libavformat API directly because it is then possible +to feed the same packets to several muxers directly. + +@table @option + +@item use_fifo @var{bool} +If set to 1, slave outputs will be processed in separate thread using @ref{fifo} +muxer. This allows to compensate for different speed/latency/reliability of +outputs and setup transparent recovery. By default this feature is turned off. + +@item fifo_options +Options to pass to fifo pseudo-muxer instances. See @ref{fifo}. + +@end table + +The slave outputs are specified in the file name given to the muxer, +separated by '|'. If any of the slave name contains the '|' separator, +leading or trailing spaces or any special character, it must be +escaped (see @ref{quoting_and_escaping,,the "Quoting and escaping" +section in the ffmpeg-utils(1) manual,ffmpeg-utils}). + +Muxer options can be specified for each slave by prepending them as a list of +@var{key}=@var{value} pairs separated by ':', between square brackets. If +the options values contain a special character or the ':' separator, they +must be escaped; note that this is a second level escaping. + +The following special options are also recognized: +@table @option +@item f +Specify the format name. Useful if it cannot be guessed from the +output name suffix. + +@item bsfs[/@var{spec}] +Specify a list of bitstream filters to apply to the specified +output. + +@item use_fifo @var{bool} +This allows to override tee muxer use_fifo option for individual slave muxer. + +@item fifo_options +This allows to override tee muxer fifo_options for individual slave muxer. +See @ref{fifo}. + +It is possible to specify to which streams a given bitstream filter +applies, by appending a stream specifier to the option separated by +@code{/}. @var{spec} must be a stream specifier (see @ref{Format +stream specifiers}). If the stream specifier is not specified, the +bitstream filters will be applied to all streams in the output. + +Several bitstream filters can be specified, separated by ",". + +@item select +Select the streams that should be mapped to the slave output, +specified by a stream specifier. If not specified, this defaults to +all the input streams. You may use multiple stream specifiers +separated by commas (@code{,}) e.g.: @code{a:0,v} + +@item onfail +Specify behaviour on output failure. This can be set to either @code{abort} (which is +default) or @code{ignore}. @code{abort} will cause whole process to fail in case of failure +on this slave output. @code{ignore} will ignore failure on this output, so other outputs +will continue without being affected. +@end table + +@subsection Examples + +@itemize +@item +Encode something and both archive it in a WebM file and stream it +as MPEG-TS over UDP (the streams need to be explicitly mapped): +@example +ffmpeg -i ... -c:v libx264 -c:a mp2 -f tee -map 0:v -map 0:a + "archive-20121107.mkv|[f=mpegts]udp://10.0.1.255:1234/" +@end example + +@item +As above, but continue streaming even if output to local file fails +(for example local drive fills up): +@example +ffmpeg -i ... -c:v libx264 -c:a mp2 -f tee -map 0:v -map 0:a + "[onfail=ignore]archive-20121107.mkv|[f=mpegts]udp://10.0.1.255:1234/" +@end example + +@item +Use @command{ffmpeg} to encode the input, and send the output +to three different destinations. The @code{dump_extra} bitstream +filter is used to add extradata information to all the output video +keyframes packets, as requested by the MPEG-TS format. The select +option is applied to @file{out.aac} in order to make it contain only +audio packets. +@example +ffmpeg -i ... -map 0 -flags +global_header -c:v libx264 -c:a aac + -f tee "[bsfs/v=dump_extra]out.ts|[movflags=+faststart]out.mp4|[select=a]out.aac" +@end example + +@item +As below, but select only stream @code{a:1} for the audio output. Note +that a second level escaping must be performed, as ":" is a special +character used to separate options. +@example +ffmpeg -i ... -map 0 -flags +global_header -c:v libx264 -c:a aac + -f tee "[bsfs/v=dump_extra]out.ts|[movflags=+faststart]out.mp4|[select=\'a:1\']out.aac" +@end example +@end itemize + +Note: some codecs may need different options depending on the output format; +the auto-detection of this can not work with the tee muxer. The main example +is the @option{global_header} flag. + +@section webm_dash_manifest + +WebM DASH Manifest muxer. + +This muxer implements the WebM DASH Manifest specification to generate the DASH +manifest XML. It also supports manifest generation for DASH live streams. + +For more information see: + +@itemize @bullet +@item +WebM DASH Specification: @url{https://sites.google.com/a/webmproject.org/wiki/adaptive-streaming/webm-dash-specification} +@item +ISO DASH Specification: @url{http://standards.iso.org/ittf/PubliclyAvailableStandards/c065274_ISO_IEC_23009-1_2014.zip} +@end itemize + +@subsection Options + +This muxer supports the following options: + +@table @option +@item adaptation_sets +This option has the following syntax: "id=x,streams=a,b,c id=y,streams=d,e" where x and y are the +unique identifiers of the adaptation sets and a,b,c,d and e are the indices of the corresponding +audio and video streams. Any number of adaptation sets can be added using this option. + +@item live +Set this to 1 to create a live stream DASH Manifest. Default: 0. + +@item chunk_start_index +Start index of the first chunk. This will go in the @samp{startNumber} attribute +of the @samp{SegmentTemplate} element in the manifest. Default: 0. + +@item chunk_duration_ms +Duration of each chunk in milliseconds. This will go in the @samp{duration} +attribute of the @samp{SegmentTemplate} element in the manifest. Default: 1000. + +@item utc_timing_url +URL of the page that will return the UTC timestamp in ISO format. This will go +in the @samp{value} attribute of the @samp{UTCTiming} element in the manifest. +Default: None. + +@item time_shift_buffer_depth +Smallest time (in seconds) shifting buffer for which any Representation is +guaranteed to be available. This will go in the @samp{timeShiftBufferDepth} +attribute of the @samp{MPD} element. Default: 60. + +@item minimum_update_period +Minimum update period (in seconds) of the manifest. This will go in the +@samp{minimumUpdatePeriod} attribute of the @samp{MPD} element. Default: 0. + +@end table + +@subsection Example +@example +ffmpeg -f webm_dash_manifest -i video1.webm \ + -f webm_dash_manifest -i video2.webm \ + -f webm_dash_manifest -i audio1.webm \ + -f webm_dash_manifest -i audio2.webm \ + -map 0 -map 1 -map 2 -map 3 \ + -c copy \ + -f webm_dash_manifest \ + -adaptation_sets "id=0,streams=0,1 id=1,streams=2,3" \ + manifest.xml +@end example + +@section webm_chunk + +WebM Live Chunk Muxer. + +This muxer writes out WebM headers and chunks as separate files which can be +consumed by clients that support WebM Live streams via DASH. + +@subsection Options + +This muxer supports the following options: + +@table @option +@item chunk_start_index +Index of the first chunk (defaults to 0). + +@item header +Filename of the header where the initialization data will be written. + +@item audio_chunk_duration +Duration of each audio chunk in milliseconds (defaults to 5000). +@end table + +@subsection Example @example -avconv -i in.mkv -c hevc -flags +cgop -g 60 -map 0 -f segment -list out.list out%03d.nut +ffmpeg -f v4l2 -i /dev/video0 \ + -f alsa -i hw:0 \ + -map 0:0 \ + -c:v libvpx-vp9 \ + -s 640x360 -keyint_min 30 -g 30 \ + -f webm_chunk \ + -header webm_live_video_360.hdr \ + -chunk_start_index 1 \ + webm_live_video_360_%d.chk \ + -map 1:0 \ + -c:a libvorbis \ + -b:a 128k \ + -f webm_chunk \ + -header webm_live_audio_128.hdr \ + -chunk_start_index 1 \ + -audio_chunk_duration 1000 \ + webm_live_audio_128_%d.chk @end example @c man end MUXERS _______________________________________________ ffmpeg-cvslog mailing list ffmpeg-cvslog@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-cvslog
