# mediaTrackProperties

URL: https://www.caprid.com/docs/reference/typescript/caprid/relay/media/functions/mediatrackproperties/

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

Defined in: [relay-sdks/ts/src/media-track-properties.ts:59](https://github.com/caprids/relay-sdks/blob/main/ts/src/media-track-properties.ts#L59)

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()`:

```ts
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`](https://www.caprid.com/docs/reference/typescript/caprid/relay/media/type-aliases/mediakind/) |
| `options?` | [`MediaTrackPropertiesOptions`](https://www.caprid.com/docs/reference/typescript/caprid/relay/media/interfaces/mediatrackpropertiesoptions/) |

## Returns

[`PublishProperty`](https://www.caprid.com/docs/reference/typescript/caprid/relay/index/interfaces/publishproperty/)[]