URL Parameters

Parameters implemented in livesim1 and livesim2

The following table should include all URL parameters in either livesim1 or livesim2

Parameter	Values	Description	livesim2	livesim1
tsbd	int	TimeShiftBufferDepth in seconds	Yes	Yes
segtimeline	1 (=true)	Generate live MPD using SegmentTimeline with $Time$	Yes	Yes
ato	float or "inf"	availabilityTimeOffset in seconds (inf = infinity, all segments available)	Yes	Yes
chunkdur	float	Chunk duration for on-the-fly chunking	Yes	Yes
ltgt	int	Low-latency target in milliseconds	Yes	No
timesubsstpp	string	List of comma-separated languages with auto-generated stpp subtitles	Yes	No
timesubswvtt	string	List of comma-separated languages with auto-generated wvtt subtitles	Yes	No
timesubsdur	int > 0	Cue duration of generated time subtitles in ms (default 900)	Yes	No
timesubsreg	0 or 1	Region 0 (bottom) or 1 (top) for time subtitles	Yes	No
start or ast	int >= 0	Sets the availabilityStartTime relative to Epoch	Yes	Yes
stop	int > 0	Sets the stop time (for time-limited events)	Yes	Yes
startrel	int	Sets relative startTime via Location with start parameter	Yes	Yes
stoprel	int	Sets relative stopTime via Location with stop parameter	Yes	Yes
dur	int	Sets a presentation duration for multiple periods	No	Yes
timeoffset	int	Sets time offset in second vs NTP	No	Yes
init	int > 0	Offset time for early init segment availability	No	Yes
mup	int	MinimumUpdatePeriod in seconds	Yes	Yes
modulo	int > 0	Make this number of time-limited sessions every hour	No	Yes
tfdt	1 (=true)	Use 32-bit tfdt (needs more recent availabilityStartTime)	No	Yes
cont	1 (=true)	Continuous update of MPD AST and segNr	No	Yes
periods	int > 0	Make this number of periods per hour	Yes	Yes
xlink	int > 0	Make this number of xlink periods per hour	No	Yes
etp	int > 0	Make this number of early terminated periods per hour	No	Yes
etpDuration	int > 0	Add early terminated period duration for multiple periods	No	Yes
insertad	1 (=true)	Insert an ad via xlink	No	Yes
continuous	1 (=true)	Insert period continuity signaling (only valid when periods is set)	Yes	Yes
segtimelinenr	1 (=true)	Generate live MPD using SegmentTimeline with $Number$	Yes	Yes
baseurl	url string	Add this top-level BaseURL in all configurations	No	Yes
statuscode	string	Periodic status code responses to segment requests	Yes	No
traffic	string	Periodic traffic problems using one or more BaseURLs	Yes	No
peroff	int > 0	Period offset in seconds	No	Yes
scte35	int > 0	Add these many SCTE-35 splice insert periods every minute	Yes	Yes
utc	string	hyphen-separated list of UTCTiming methods and make into list	Yes	Yes
snr	int	Set startNumber in MPD. -1 translates to no value in MPD (fallback to default = 1)	Yes	Yes
spd	int > 0	suggestedPresentationDelay in seconds	Yes	Yes
sidx	1 (=true)	Insert sidx box in every segment	No	Yes
patch	int > 0	Insert PatchLocation element in the URL	Yes	No

scte35 parameter

By using the scte35_x URL parameter, emsg boxes with SCTE-35 messages will be inserted 1, 2, or 3 times a minute.

x	dur	starts
1	20s	hh:mm:10
2	10s	hh:mm:10, hh:mm:40
3	10s	hh:mm:10, h:mm:36:h:mm:46

The SCTE-35 emsg boxes are included in the segment that includes the media time which is 7s before the start of the SCTE-35 break.

The emsg box uses the schemeIdUri "urn:scte:scte35:2013:bin" and should follow SCTE-214-1 2022. This means that emsg version 1 is used, and the timescale of the emsgbox is the same as the media timescale. The emsg payload is a binary SCTE-35 splice_insert message with PTS time based on splice time module MPEG-2 TS wrap-around.

Query-string time specification

There are a few query-string parameters that can be used to specify the wall-clock time that livesim2 uses to generate a response. In this way, it is possible to get the response corresponding to a request at a specific time in the past or in the future.

The parameters are

parameter	value	meaning
nowMs	int	Time since epoch start 1970-01-01 in milliseconds
nowDate	ISO 8601 timestamp	A UTC time specified (will be converted to nowMS as milliseconds + 1)
publishTime	ISO 8601 timestamp	similar to nowDate, but used to fetch an MPD with a certain publishTime

With these timestamps, one can for example ask for a segment at a specific time and see it it is available:

livesim2/asset/video/2323322.cmfv?nowMS=1713528527000.

It also applies to MPD Patch where one can ask for a patch relative a publishTime with a nowDate 18s later.

/patch/.../Manifest.mpp?publishTime=2024-04-16T07:34:38Z&nowDate=2024-04-16T07:34:56Z"

This request will generate the same MPD patch document totally independent of the current wall-clock time.

Note.In general, it should be possible to use an RFC-3339 timestamp instead of an ISO 8601 timestamp.