I'm trying to create a 48kbit stream from my main 128k stream (icecast2 mp3). I've created a second mount point, but I can't see how to set the source to be the main stream, only the auto-DJ. I know I can do this by looping the main stream through liquidsoap and back into icecast, but I'd much prefer to be able to do it inside centova. I'm finding the docs in this area are very vague, and I've not found any example configs. What's the right way to do this?