From: "Aaron Bishop" <[EMAIL PROTECTED]>
Subject: Re: setting 10 rooms in a house for realvideo broadcast
Math is important here. A full T3 is 30 T1 lines (well, not literally) but
it comes out to about 45mbps (megabits).
So if each stream is going to be 220kbps (kilobits) then that means a
single T3 dedicated to NOTHING but
streaming (no webhosting, no email, no nothing but streaming) is 45000kbps
/ 220kbps = ~200 simultaneous
streams.
That could be problematic right there. I assume that if you can afford the
hefty cost of a T3 then you can afford a
separate T1 for any email or webhosting that's going on there. Maybe 2
T1's but one'll probably do. But if you're
aiming for 1000 viewers all at once then that ain't gonna happen!
That 11th PC...you mean that's going to be the REAL Server...not a proxy
server, right? If I remember correctly
the link between an encoder and server cannot run through a router,
firewall, or proxy server. It just won't work.
Another thing to consider here is whether or not that single RealServer can
handle the strain of 200 people trying
to watch the video on it. Probably not, but if you got a really hefty
machine it might. Others on the list are more
knowledgeable than I on this matter.
I think shotgun mics would be appropriate here...better range. And
contrary to public misconception, a shotgun
mic does not magically pick up sound only where you aim it...that's a
parabolic mic (those big dishes you see
on the sidelines at US football games). A shotgun mic placed in a upper
corner and aimed at the center of a room
ought to pick up most of the room nicely...depending on how big the room is
and what the acoustics are.
Archiving...again - math to the rescue: 220kbps x 60 seconds x 60 minutes x
24 hours / 1000 (to make it megabits) =
19008 megabits per day. 1 byte = 8 bits...so 19008 / 8 = 2376 MB per day,
or 2.3 gigs. For ONE feed. Also keep
in mind that this is SINGLE RATE....**NOT** SURESTREAM. If it's surestream
the size will be awesome! For
example, you have surestream at 220kbps, 100kbps, and 45kbps. Total
equalls 365kbps + 10% (headroom)
= 402kbps.
402kbps x 60 seconds x 60 minutes x 24 hours / 1000 / 8 = 4341 MB per day,
or 4.3 gigs...again, for ONE feed.
Ouch.
For capture boards, I've heard good things about the Osprey 1000.
Good luck!
You might also want to check out www.purebroadcasting.com - they have
webcams rigged to be controlled by a
Java-based on-the-browser control panel. The end-user can zoom in and out,
and aim the camera left, right, up,
down in real time (well, 2 second delay). They have a webcam in their
office to demonstrate this and I have to
say it's mighty cool...
Aaron Bishop
CW Audio Engineer
[EMAIL PROTECTED]
From: "Yvan Gagnon" <[EMAIL PROTECTED]>
Subject: setting 10 rooms in a house for realvideo broadcast
I have an opportunity to help coordinate a large realvideo broadcasting
project that would involve the setting up of an entire house with about 10
different webcams. Ideally, we'd like for this to be a live, 24 hour
broadband surestream multicast, encoding both audio and video, probably
220kbps @ 320x240 & 15fps max. Here's what I'm thinking we would need to
make this happen:
[ I'd be grateful for any suggestions or corrections regarding this ]
1) Have a T3 line installed in the house.
2) Buy eleven PCs, .. one that would be used as a proxy server, and the
other ten as dedicated encoders (one for each room) and install a
video/audio capture board and NIC in each of the encoder boxes.
3) Buy 10 decent quality cameras, and 10 microphones.
4) Purchase 10 licensed copies of RealProducer Plus
5) Set up a contract with a realvideo hosting company that specializes in
multicasting
Now, .. SOME QUESTIONS:
1) If we wanted to set up some kind of "control room" where we could
monitor
each of the live feeds, what would be the best and most cost effective way
to do that? Would we have to buy 10 additional workstations (one for each
stream), .. or is there any way that we could monitor each of the streams
simultaneously using just one, high-powered PC (and a large monitor)?
2) Is there any way to archive a live encoded session to a network drive?
Or does it only work with a local hardrive?
3) Assuming that the video would be encoded at 220kpbs (Surestream) @
320x240 & 15fps, how large can we expect our resulting 24-hour archived
files to be for each of the feeds?
4) Which audio/video capture board would work best for this sort of high
bitrate live encoding?
[ I'd need something that works with NT, RealProducer, and has audio
inputs as well ]
Again, I'd greatly appreciate any advice or corrections anyone here might
have to offer.
Thank you,
-- [EMAIL PROTECTED]
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