Setting priority on RTC session sender's encodings

[marcovidonis]

I'm looking at adding the option to set the sender's priority when adding local media stream tracks to the peer connection in RTCSession. In some applications, this could be used as a QoS marker, to make sure the user agent allocates a higher bandwidth, for example.

The way I would do it this:

this._localMediaStream = stream;
if (stream)
{
  stream.getTracks().forEach((track) =>
  {
    let sender = this._connection.addTrack(track, stream);
    const params = sender.getParameters();
      params.encodings = params.encodings.map((e) => {
        if (!this.priority) return e;
        if (e.priority) {
          e.priority = this.priority;
        }
        if (e.networkPriority) {
          e.networkPriority = this.priority;
        }
        return e;
      });
      sender.setParameters(params);
  });
}

Would this addition be of interested to the project? If so, I'd be happy to open a PR for it.

Also, I'm not too sure where the best place would be to define this.priority: in RTCSession.js itself, perhaps? Or better pass it to the constructor?

[kstarzyk]

I've verified This works in Chrome ( 130.0.6723.117) but does not work in Safari (17.x) - both desktop and mobile (rdcp is set to 0 - can be checked in wireshark capture).

[JoshuaGeiger]

I'm curious when/if this will get merged. The attached PR looks good to me and we've been using it as a patch for some time now.