Telepresnce Solutions and SVC

The Future of Telepresence
Alex Eleftheriadis, alex@vidyo.com

What is Telepresence?
Wikipedia:
Telepresence refers to a set of technologies which allow a person to feel as if they were present, to give the appearance that they were present, or to have an effect, at a location other than their true location.
Alternatively:
Videoconferencing sucks! What can you do to make it better if you have all the money you need?

Lessons Learned Elsewhere
Computing
Networking
Communications

DEC VAX (1977, 0.5 MIPS)
VAX 11/780 (first two cabinet sections), shown with Unibus expansion cabinet (middle cabinet section), two tape drives, two RP05 or RP06 removable pack disk drives, a DECwriter printing terminal, and a VT52 CRT terminal

iPhone 3G (2008, 1250 MIPS)

Lessons Learned Elsewhere
Computing
Fast
Personal
Portable
Networking
Scalable
Ubiquitous
Communications
Reliable
Ubiquitous
Mobile

Telepresence Today
Extremely expensive
Not scalable
Not portable
Not personal
Very high quality
=> Traditional videoconferencing: same, but sacrifices quality for low cost.

Quality of Experience
100 hours/month
Telepresence quality
At least SD quality per face
Total delay under 250ms latency
Legacy video conferencing quality
Quality of Experience
10 hours/month
Type
Desktop
Executive
Room
Telepresence
Cost
$100’s
$1000’s
$10,000’s
$100,000’s

Key Videoconferencing System Characteristics
Rate Matching
Support for heterogeneous endpoints and access networks
Personalized Layout
Each user selects the resolution and users he/she wants to see
Low Delay
Interactivity requires <250msec end-to-end
Error Resilience
Tolerance to packet loss rates >10%
Error Localization
An error in one user should not affect other users
Complexity
Lower complexity = Lower cost
Low complexity allows to integrate with existing network services (e.g., in cheap routers)
=> How can we have all that, but with high quality and scalability?

H.264 SVC
Scalable Video Coding (SVC)
Developed by JVT (=Joint Video Team of ITU and ISO)
SVC is Amendment 3 to H.264 AVC
Most of SVC is in Annex G of H.264 AVC
CFP April 2004, Consented in Nov 2007
RTP payload format nearly completed
Architecture centered on VidyoRouter™ (“VRU”)

Temporal Structure of Non-Scalable Codecs

Temporal Scalability

Spatial Scalability
Prediction
Coding
Multiplex
Prediction
Coding
SVC
Bitstream
H.264/AVC-compatible
base layer
Prediction
Coding
Scale
Scale

Temporal + Spatial Scalability

QVGA
30 fps

VGA
15 fps

What does the VidyoRouter do?
High Resolution
High Frame Rate
2 Mbps
High Resolution
Medium Frame Rate
VidyoRouter™
1 Mbps
Medium Resolution
Medium Frame Rate
500 Kbps
High Resolution
High Frame Rate
Low Resolution
Low Frame Rate
150 Kbps

Traditional MCU Architecture
High Cost
High Delay
Quality Loss from Cascaded Encodings
ENCODE
ENCODE
DECODE
DECODE
COMPOSE
ENCODE
DECODE

VidyoRouter™vs. MCU
VidyoRouter is simply an application layer router
Nearly zero-delay (~20 msec), allows interactive multi-point sessions
Eliminates video quality loss due to transcoding
Rate matching and personal layout are simple routing decisions
Error localization and robustness up to 20% packet loss rates
Computing power that rides the Intel® curve
Endpoint processing of the video from different participants makes the VidyoRouterhighly scalable
Similar complexity to other network appliances

Significant Impact
Minor or No Impact
Base Layer
Conventional Coding
Scalable Coding
Enhancement Layer
SVC+VR Eliminates Error Resilience Problem

Temporal Scalability

Concluding Remarks
Videoconferencing and telepresence will remain “small”, unless our technology enables scaling with high quality and low cost.
Video coding scalability and the video router architecture allow:
Replacement of the MCU with a much simpler, scalable device – the Video Routing Unit (VRU)
Very high error resilience (=high quality user experience)
Co-existence of lower-end systems with telepresence systems
Use of standard (Intel) hardware components – riding the Intel curve
These concepts finally solve 30-year-old packet video problems, and are the key ingredients for making telepresence “personal”.

IMTC SuperOp! Room

Concluding Remarks
Videoconferencing and telepresence will remain “small”, unless our technology enables scaling with high quality and low cost.
Video coding scalability and the video router architecture allow:
Replacement of the MCU with a much simpler, scalable device
Very high error resilience (=high quality user experience)
Use of standard (Intel) hardware components – riding the Intel curve
These concepts finally solve 30-year-old packet video problems, and are the key ingredients for making telepresence “personal”.
Can I get the same benefit from simulcasting? Or without two spatial layers? Or ….?
Partially. If you use part of the recipe, you get only part of the flavor.
Wait … So, the future of telepresence is … Vidyo?

Thank You!

Telepresnce Solutions and SVC

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