John Roston and Jeremy R. CooperstockCentre for Interdisciplinary Research in Music Media and TechnologyMcGill University
Low-latency HD:Shared Spaces and
Undersea Window
Low-latency
Videoconferencing: The Future?
Zack Snyder’s “Online Jam”, October 2001
For those with DSL at home...
yeah, right!
Pinchas Zuckerman, Columbia U, NYC
Wu Ji, Canarie ARDNOC, Ottawa
“Playing Together” experiment
New York-Ottawa, Remote Masters class, Dec. 8, 2000
Latency: The Interaction-Killer
or put another way...
0
200
400
600
800
1000
1200
1400
1600
HD-SDI SDI DV/HDV MPEG
Mbps
Bandwidth vs. Latency
• near-equivalent quality of encoded video (HD-SDI vs HDV or SDI vs DV/MPEG) at greatly reduced bandwidth
• but… compression takes time
* This is a theoretical “best-case” scenario. Actual performance may vary. The manufacturer makes no warranties, either express or implied, and will not be held liable for damage resulting from use of the product. Certain restrictions may apply. Offer void where prohibited by law. Batteries not included.
compress transmit
100 20 4030 50 7060 80
networks light speed: Mtl-LA
net latency Mtl-LA
large ensemble
activity smallensemble
lip synch
MPEG*acquire
90 100ms
speech, drumming
Tolerated Synchronicity
Current Projects
Going deep under… to 2000m
HD video over new undersea networks –VENUS and NEPTUNE
“Undersea Window” Project
VENUS – Test Camera 100m
NEPTUNE – Cameras 2,000m
System Architecture
Shared Spaces: Panoramic High-Def
See everything - no camera panning
Conference Room Configuration
C4 OME@BCnet
to servers w/GbE i/f
C4 OME@RISQ
UBC 10G switch
McGill 10G switchRISQ
fibreBCnetfibre
OC-19210GWan Phy
to servers w/GbE i/f
10GWan Phy
CA*net 4
local loop for end-end lightpath prgram scope
Network Architecture
New challenge: Real-time mosaicing
Sample Result
Can your camera do this?
Previous Projects
Distributed Violin Duet
McGill-Université de Montréal demo, Nov. 21, 2001 • IP over 1 Gbps fiber link • < 30ms latency
McLuhan: “The medium is the message”
Cooperstock's Corollary:
“The medium must be faster than the message.” *
* but between protocol deficiencies (TCP, UDP), competing data flows, process scheduling on a budget, ARQ (retransmission management) without QoS, interface HW/SW “uncooperativeness”, aggressive router policies, multi-format support, echo suppression, and interface complexity… it’s much more than just the medium
Violin Masters Class
Montreal-Ottawa Trial with Pinchas Zuckerman, Feb. 20, 2002
Size does matter
Distributed Jazz Jam
Montreal-Stanford (CCRMA), Research Demo, Oct. 24, 2002
The “Sweet Spot” Problem
Vibrosensory Transmission
VRQ demo, March 8, 2004
… and another application
Thank you.Further information available:
http://ultravideo.mcgill.edu