Need VIDEO CALLING solution

I'm unable to find a video calling solution that I can eventually integrate to my existing web app that has following features: - 2 or more persons can video/audio call - admin can go into anyone's call (to monitor) without getting noticed - call should automatically get recorded - one can write notes of the meeting during the meeting - one can ask few quiz questions from other in a beautiful way (through the system). - if a user wants, he should be able to split screen view in a way that on the half of the screen he/she should see the other participant and on the other half he can share the screen or a document. I'm really open to your suggestions, and flexible, whether we need a solution from scratch or we can customize an open source solution or if there is already a solution out there that supports all of this.