I'm currently developing a WebRTC Master→Many (One→Many) Server.
For the UI I created a simple WebSocket Connection which sends an API Packet to the Server, when a Client enables a Media Stream.
The Packet contains the ID of the RTCRtpSender, this Mechanism works on Chrome and Edge (Chromium).
Sadly, FireFox changes the MediaStreamTrack ID when adding to Peer Track.
I am unfortunately limited by the track parameters as I am using a Native JNI wrapper of the WebRTC Native Lib.
Does anyone have a workaround for this, I didn't find anything in the Mozilla docs.