There is a demo which comes with UV4L demo OS for Raspberry PI, https://raspberry:8080/stream/webrtc. When i run it on a macOS computer (Firefox browser), and select that a screen is to be shared, it always says 'no suitable video device found!' and apparently doesn't connect anywhere. Same happens when i go there on a Chromium browser on a Raspberry PI itself. There doesn't seem to be any error messages anywhere - some deprecation warnings but no more than that:
onopen() webrtc:197:25
navigator.mozGetUserMedia has been replaced by navigator.mediaDevices.getUserMedia webrtc:251:32
WebRTC interfaces with the “moz” prefix (mozRTCPeerConnection, mozRTCSessionDescription, mozRTCIceCandidate) have been deprecated. webrtc:105:25
{"iceServers":[{"urls":["stun:stun.l.google.com:19302","stun:192.168.0.101:3478"]}]} webrtc:104:21
onaddstream is deprecated! Use peerConnection.ontrack instead. webrtc:107
peer connection successfully created! webrtc:110:21
URL.createObjectURL(MediaStream) is deprecated and will be removed soon. webrtc:255:60
call(), request={"what":"call","options":{"force_hw_vcodec":false,"vformat":"60"}} webrtc:193:25
message =message webrtc:281:25
Where shall i look into?
Clarification: i can see my desktop in a 'local' box, so sharing has been successful, same on Raspberry PI. But it never goes to the other side, i can't even use the data channel - it is greyed out - so apparently no connection happens, at all.