Quake Demo Spectating?

Hi

I’m searching for a way to do the following:
I want to spectate a running Quake demo and move around in it like with noclip activated to record some Videos of it.

I already found remstud2: https://code.google.com/p/remstud2/
It can load a demo and operate as a server so you can join and change the camera position an stuff like this. It can even pause and continue the playback of the demo. But the tool don’t works for me. Once running I try to connect and get the message “connection accepted”. Nothing more happens. In the console window of remstud2 it says “client connected, start editing” but a short time later says “client deconnected”. Sometimes it crashes.

Is there another way to do this?