Freeswitch also had a video_mcu built in and bundled with current bbb, but the issue is CPU requirements to mix a composite video of all the cams.. so in past trying to mix 25 cams, into 1 composite consumed many cores for just that 1 function.
Would be interested to understand how many cores are needed to mixed X number of screens with ant.
Almost like Live Streaming, needs another distributed set of servers for production scaling.
Paulo can speak out to this more, but the new sfus being evalauted allow for all media to stream and be bundled into a single peer connection.
Also with simulcast, 3 streams (low/med/hi) can be sent when publishing, and a bunch of low res streams can be sent thru single peer connection to enable scale, and give a composited display in browser.
regards,
Stephen