Feature request: Multi-view switching

[victorges]

Moved from https://github.com/livepeer/webrtmp-server/issues/4 by @chrishobcroft

This feature request is for the ability to connect more than one camera source, and allow rudimentary switching between cameras.

A prototype could be to allow switching between camera and screenshare, in order to minimise the complexity likely associated with allow >1 camera to connect to a session.

I have no idea how the UI would look for this, but OBS Studio ought to provide some basic inspiration. For example, you might even want to call this option "Studio Mode":