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