Time to take a moment and describe today's feed from the encoding
perspective. We do lots of on-site coverage, and usually bring in a
dedicated ISDN for the encoder feed back to the server(s) and out to the
network. In UDP mode, our encoder and server can buffer quite deeply (say,
300 seconds) to accommodate some pretty significant network outages. Until
today, we couldn't imagine a scenario where this wasn't good enough, but as
luck would have it, we were wrong. Fortunately today's net problem was
resolved by the end of the general session and Tuesday *should* be much
cleaner.
On the subject of camera positioning and exposure, we know, it was not good.
I think we can pull together a somewhat more coherent set of post-produced
presentations with what we have on tape -- we'll find out when we get a look
at them. But we should have better cameras, a video switcher, and somewhat
better lighting to do this virtual conference thing right. Next meeting?
I heard lots of questions on multicast today...here's how it works with
RealMedia. If you have decent MBONE connectivity, you'll negotiate
multicast when you connect to the audio or video stream. If you don't, the
client falls back to unicast UDP mode. If even that fails (say you're
behind a firewall), it rolls to TCP mode, and will ultimately resort to HTTP
"cloaking" if nothing else works. Users can override the automated
fall-back through the preferences dialog if there's a strong preference for
a particular mode.
Jeffrey Payne, GM Broadcast Operations
RealNetworks, Inc.
