Hallo!
I'm sure you could do this entirely with Python,
which would suit Trac.
Not that I'd have a clue where to start, well not much of one anyway.
You could use Plone, which already has many communication-tools, and
write an additional product in python for it ...
(where you could in example use pd or anything else and stream with an
icecast2 server ...)
a little howto you can make something (Plone and communication with pd
...) is here:
http://pdradio.iem.at/howto
(of course not that advanced as you want it ... ;)
LG
Georg