Limiting WebRTC bitrate: issues with Firefox-CodePudding

I am trying to limit the bitrate of a WebRTC video stream sent from the browser. With Chromium-based browsers, I simply set the maxBitrate field of the sendEncodings field at addTransceiver time. Since Firefox doesn't support sendEncodings, I need to call getParameters on the sender, tweak its encodings field, then call setParameters.

This works quite well in the simulcast case; however, in the non-simulcast case (encodings is an array containing a single entry), Firefox appears to ignore the maxBitrate field, and always sends at its maximum bitrate (2.5kbit/s).

Is encodings[0].maxBitrate supposed to work in Firefox in the non-simulcast case?

CodePudding user response：

After some investigation, it turns out that Firefox doesn't obey the bandwidth limitation in the non-simulcast case if the rid field is set. So this works in both Chromium and Firefox:

let p = sender.getParameters();
p.encodings = [{maxBitrate: 700000}];
await sender.setParameters(p);

while this only works in Chromium:

let p = sender.getParameters();
p.encodings = [{rid: 'h', maxBitrate: 700000}];
await sender.setParameters(p);