For a long time now, machines have been powerful enough to run all AG
services, including capturing multiple video streams, on a single
machine. For a desktop node with just a single camera, this is great.
The disadvantage of a single machine with multiple cameras is that
each video capture uses a separate vic instance. This means that, as
well as anything else you may want to run on the console display, you
additionally have a bunch of vic instances - each of which has a
thumbnails for all streams from external sites as well as for the
stream its capturing. This can be quite confusing - especially for
"ordinary users" that you may be letting run their own meetings after
doing an initial setup for them.
The advantage of 2 separate machines is that the VideoProducerServices
are tucked away, out of sight, on the capture machine, leaving the
display machine with just a single vic instance (from a
VideoConsumerService).
A few years ago we used Xen to run the VideoProducerServices in a
virtual capture machine on the same physical hardware as the display
machine. It was a bit messy to set up and needed kernel patches, so
ultimately not easy to maintain and we never persevered with it.
There's now a new virtualisation technology, with all the necessary
bits already in the kernel (since 2.6.29), called Linux Containers
(LXC). I've used this to make a prototype room node (separate display
and capture machine with multiple cameras) on a single physical
machine. Its still a bit messy to set up initially but well worth the
effort. Construction details are at:
http://www.vislab.uq.edu.au/research/accessgrid/software/lxcag/
chris
Christoph Willing +61 7 3365 8316
QCIF Access Grid Manager
University of Queensland
