The event timeline track provides a mechanism to associate ad-hoc event metadata with the broadcast. Use-case examples include live sports score data, GPS coordinates of race cars, SAP-types for media segments or active speaker notifications in web conferences.
To allow the client to bind this event metadata with the broadcast content described by the media timeline track, each event record MUST contain a reference to one of Media PTS, wallclock time or MOQT Location.
Event timeline tracks are optional. Multiple event timeline tracks can exist inside a catalog. The type & structure of the data contained within each event timeline track is declared in the catalog, to facilitate client selection and parsing.