media tool requirement

[Robert Olson]

thought I'd throw this out since I've been assuming we'd have do it at some 
point

for implementing tight scoping of users, we'd like to be able to quickly 
and universally change media stream encryption keys on the fly. the thing 
that makes this hard is the management of transitions so we don't get 
glitches, espeically in the audio. this will likely require close 
examination of the data stremas during the transition periods, possibly 
attempting decoding the streams with both keys until all streams have 
switched to the new one.

there is also a communication requirement in that we need to get hte keys 
pushed out from the venue to all clients in a close-to-synchronized manner, 
but I'm not as worried about that.