How to transfer and read a video stream from a webcam?

Question

JavaScript

I'm writing a video chat using quickblox.com . It turned
out to achieve a stable connection between 2 people . A
group call to the sdk has not yet been implemented,
but this chain needs a 3rd one, which takes a passive role. that is, he does not transmit his video, but only sees the video of those 2x.
got the idea to run node.js. each of those two will push their own video stream into it, and the third will just read
how to implement it?
or tell me another way to solve the problem?