What is the best open source video chat web client? I would love something with visible feedback on connection quality, especially if it was able to reduce ban

What is the best open source video chat web client? I would love something with visible feedback on connection quality, especially if it was able to reduce bandwidth usage as possible automagically (switch video to static image / off, reduce audio kbps, etc.) to degrade gracefully. Maybe supporting "push to be the only mic unmuted" could lessen the bandwidth needed.