Video freezing (track muted event) for some clients but not others

Hi,

we’re developing our own client on top of lib-jitsi-meet, JVB, etc.

What we’re seeing is that, if, for instance, you have clients A,B,C in a jitsi room, occasionally, A will freeze for B but not C. B also receives a track mute event in that case (the actual MediaTrack, not JitsiTrack). B will continue to receive C’s video with no issues

The track will usually emit an unmute event and resume after some time (anything from some milliseconds to more than a minute).

We’re trying to figure out what is causing this or how to mitigate it. Our understanding is that JVB sends the same media to all clients connected to the same room. Is this correct or is there a chance that JVB freezes a track if a client (B in this case) has low connectivity?

Also, is there a way to restart the remote stream for the receiving client, if the freeze goes on for too long? That is, without re-joining the room and so having to restart the incoming video from C.

Yes, there is a message about a participant entering/leaving lastN set send by the bridge, which is indication that the bridge will not send video for that participant, and in jitsi-meet we show a ninja icon in this case.

Yes, we have seen that event in some cases. Is this all documented somewhere? We have read the documentation about lastN and played around with the org.jitsi.videobridge.TRUST_BWE flag but still have quite a few questions. Could you maybe point me to the right place?

It’s still hard to figure out patterns - sometimes one stream freezes for everyone, sometimes just for one recipent (the recipient in question continuing to receive streams from other people).

Is there some clear way to differentiate between the two cases?

Also, in the former case, recovery seems to be very slow or never (at some point we waited for about 2-3 minutes but the stream did not restart).

In the stream frozen for one recipient case, is there an easy way to restart it or force it to resume?

Finally, we’re assuming that setting org.jitsi.videobridge.TRUST_BWE to false will interfere with simulcasting. Is that right?