Anyone done a live video broadcast thru Linux?

[David Spake]

Greetings all,

I've helping to put together a conference next year at the Airport 
Marriott and would like to live stream some of the breakout sessions 
over the net.  I can find all sorts of file served broadcast solutions, 
but finding a live solution is something else, especially coupled with 
the firewire and miniDV format.

Hardware I envision is 4 camcorders, for the video signal, running into 
4 linux boxes.  The linux box's primary purpose would be to convert the 
DV format to something streamable (Thedora, quicktime, Real, something) 
and send it to a central (on site) server.  This central server would 
then send the converted signal to a paid for remote server that would 
actually serve the signals to the audience.  It would also serve at 
least one other box that would serve as registration, and possibly one 
more if we wanted to handle live questions (via email) from the internet 
audience.

As some of the sessions will be panel discussions, I'll be running them 
thru a mixer, then running into the linux box, but that shouldn't be 
that big of a deal.

With the camcorders doing the heavy lifting of encoding, I wouldn't 
think I'd need much in the way of processing power, but that's one of 
the things I need to figure out.  Especially CPU load in converting from 
  DV to something else.

Although the Marriott only has a single T1 line, I think I can get an 
acceptable signal to the audience.

Your thoughts on possible solutions and potential pitfalls would be 
appreciated.

Dave