mediaTrackProperties

function mediaTrackProperties(kind, options?): PublishProperty[];

Defined in: relay-sdks/ts/src/media-track-properties.ts:59

The track properties that give a media track its default delivery timeout and publisher priority (spec/behavior.md, “Media publishing”), so a stall costs stale frames rather than lasting latency. Pass them to registerTrack with the track’s format properties, such as @caprid/moq-media’s locTrackProperties():

const video = publisher.registerTrack({
  track: 'video',
  trackProperties: [...locTrackProperties(), ...mediaTrackProperties('video', { keyframeIntervalUs: 1_000_000 })],
});

The result is a SUBGROUP_DELIVERY_TIMEOUT (0x06) in whole milliseconds, rounded up: 500 ms for audio, and for video the target latency less the keyframe interval, but never less than the interval. Then a Default Publisher Priority (0x0E) that puts audio ahead of video: 16 for audio, 96 for video. moq-relay 0.17 passes it on to viewers in SUBSCRIBE_OK but orders delivery by subscriber priority alone, so on that relay it changes nothing yet. No object timeout is set: through a frame writer it would never fire, because a group’s wait for settling room is not counted and, once its stream is open, a browser’s transport takes each object at once even during a stall.

Parameters

Parameter	Type
kind	MediaKind
options?	MediaTrackPropertiesOptions

Returns

PublishProperty[]