I have started with https://doc-kurento.readthedocs.io/en/6.13.2/tutorials/java/tutorial-groupcall.html
Currently, in UI i give user option to decide whether they want only audio or audio+video call. Based on the selection, the constraints for getUserMedia() are passed and this works fine if all the user select same kind of call type.
But, say user 1 select only audio and user 2 selects audio+video, then user 1 receives audio from user 2 while on user 2 end, the html video element keeps loading.
Findings: I believe this is SDP offer issue, since offer from user 1 and respective SDP answer from user2 does not contain m=video since user 1 has opted only for audio call (this works fine)
But, offer from user 2 and respective SDP answer from user 1 does contain m=video.
So, what i want is, user 2 receive audio from 1, even though user 2 selected video call.