Transcript VideoStandards - University of Houston

University of Houston
Video Standards
Datacom II
Lecture 12 A
Second
SecondAddition
Addition
Dr. Fred L Zellner
[email protected]
http:/www.uh.edu/~fzellner
Agenda
•
•
•
•
•
•
•
Introduction and History
Technologies and Conferencing
Desktop and Collaboration
Applications
What Do You Need To Use It?
Benefits
Is It for Real?
2
Evolution of Video Conferencing
Late 1980’s
Early 1980’s
Basic technology
Early packaged systems
•Self-contained
•“Roll-abouts”
•Multipoint bridges
•Private lines, some S56
•Algorithms
•Private lines
•Big “iron”
Early 1990’s
Globalization
•ITU Standards - H.320
•Early ISDN
•Smaller Boxes
Late 1990’s
Applied videoconferencing
•Video call centers
•Mixed speeds
•Mixed networks
•Multicast
•Application specific
Mid 1990’s
Personal videoconferencing
•More standards
• H.323, H.324, T.120
•Desktop systems
•Widespread ISDN
3
Underpinning Technologies
•
•
•
•
•
•
•
Standards
Processors
Audio compression
Video compression
Displays
Cameras
Networks
Don’t forget lighting!
It makes a huge difference
4
Standards
United Nations
ITU-T
Study Group 8
T.120
Data Collaboration
Study Group 15
H.320
ISDN Videophone
H.323
IP Videophone
H.324
POTS Videophone
H.310
ATM Videophone
5
What is H.320?
ITU Video conferencing Standard encompassing several standards that address video compression, audio qual
and communications protocol. H.320 does not mean all standards are supported.
H.320 narrowband visual telephone systems &
terminal equipment—covers video conferencing audio,
video, graphics, encryption, multipoint
Video codec for audio-visual
services coding/decoding standards
H.320
Compression algorithms from
64 Kb/s to 2.048 Mb/s CIF/QCIF
H.261
H230 control and indication for
frame sync (MCU graphics)
Audio standards
G.728
H.230
G.711 3kHz audio into
56/64Kb/s streams
H.242
G.722 7kHz wideband
48/56/64 Kb/s stream
hi-fidelity audio
G.722 G.711
H.221
T.120
High
H.243 Res
graphics
H.242 establishing
communications
between audio-visual
terminals
H.221 frame structure
Px64 (P=1 to 30)
Point-to-point and multipoint data
conferences (not truly part of the
H.32X standard)
JPEG
JPEG still video standards
Custom or non-standard graphics not prohibited
by H.320—systems must be the same
Multipoint control units voice activation, user or
chairman control
6
T.120 Standard - Data Collaboration
• An international data collaboration standard (ITU)
that allows data sharing between
videoconferencing systems.
• Enables “Whiteboarding” allowing the interactive
sharing of documents and graphics.
• Provides File Transfer, a simplified method of
transferring large files.
• Wide deployment of Microsoft NetMeeting has
minimized the importance of this standard
7
What is H.323?
ITU Video conferencing Standard encompassing several standards that address IP-based video compression,
audio quality, and communications protocol. H.323 does not mean all standards are supported.
H.323 IP-based visual telephone systems & terminal
equipment—covers video conferencing audio, video,
graphics, encryption, multipoint
Compression algorithms
from 64 Kb/s to 2.048 Mb/s
CIF/QCIF
H.323
Compression algorithms twice as
efficient as H.261
H.261 H.263
H.245 control and indication
for frame sync
Audio standards
G.728
H.245
G.711 3kHz audio into
56/64Kb/s streams
G.722 G.711
G.722 7kHz wideband
48/56/64 Kb/s stream
hi-fidelity audio
G.723
G.723 6.3 Kb/s stream
G.729 8.0 Kb/s stream
G.729
H.245
H.225
H.225 frame structure
T.120
Point-to-point and multipoint data
conferences (not truly part of the
H.32X standard)
High
H.323 Res
JPEG
graphics
JPEG still video standards
Custom or non-standard graphics not prohibited
by H.320—systems must be the same
H.245 establishing
communications
Control
Multipoint control units control
8
Processors
Processor
Pentium 200 mhz
Pentium 200 MMX
Merced (1999)
Relative Horsepower
1.0
1.8
4.4
8x8 VCP (one chip)
15.0
TI C80
15.0
9
Audio Compression
Standard
G.711
Band and Bandwidth
3 KHz, 56/64 Kbps
G.722
7 KHz, 48/56/64 Kbps
G.728
3 KHz, 16 Kbps
G.723
8 KHz, 5.3-6.3 Kbps
G.729
8 KHz, 8 Kbps
10
Video Compression
Algorithm
H.261 (1994)
Relative Quality (+/- 20%)
1.0
H.263 (1997)
1.4
H.263 (1998)
1.7
11
Displays
• Today
– CRT monitors range from 25” - 40”
– Some small flat panels now available
– Standard NTSC: 525 lines max
resolution
• By 2002
– 14” - 60” flat panel plasma displays
– HDTV resolution up to 1080 lines
12
Cameras
• Today
– Resolution = 352 x 288 pixels (CIF)
• By 1999
– Resolution = 704 x 576 pixels (4 x CIF)
• By 2002
– Resolution = 1080 x 768 pixels (HDTV)
13
Networks
Network
POTS (33.6/56 Kbps)
Relative Quality
1
ISDN (BRI 128 Kbps)
ISDN (384 Kbps - 1.5 Mbps)
IP (128 Kbps - 384 Kbps)
4
12-46
1-4 *
* not empirical data
14
Desktop Evolution
Analog
Telephone
Digital
Business Set
Integrated
Multimedia
Desktop
15
Desktop Multimedia Collaboration
Text
Multimedia Is Not an Application
...It's an Adjective
Training
Mail
Graphics
Presentations
Image
MULTIMEDIA
- People - Documents
- People - Computers
- People - People
Newsletters
Sound
Multimedia Is a Progressive
Enhancement to Existing Solutions
Video
Collaboration
A Technology that Is Not Magic,
but the Effect Is Magical
Data Base
Other Horizontal
Applications
16
Global Trends
Business Forces
Customer
Requirements
Economic Conditions
– Cost containment
– Improved productivity
Work Culture
– Decentralization
– Team Structures
– Alliances/Partnerships
Globalization
Competitive Pressure
–
–
–
–
Customer Service
Quality
Time to innovate
Time to market
Reduced Complexity
Asset Preservation
Improved
Collaboration
– Intra and Inter
Company
Improved Value from
Corporate Networks
Solutions
Knowledge Worker
Tools
– Collaboration
– Presentations
– Distance
Learning/Education
Digital Infrastructure
Standards
Expected Solutions
Technology Flux
Improved Teamwork
Improved Accuracy
Improved Productivity
Market Impact
Velocity to Innovate
Shorter Business Cycles
Real Applications
• Distance Learning/Education
• Intra/Intercompany Communications
• Law Enforcement
• Telecommuting
• Remote interviewing
• Training
• Kiosk consultation
• Security
18
What do you need?
19
What do you need for 128 Kbps?
Network
ISDN BRI
20
What do you need for 384 Kbps?
ISDN BRI
ISDN BRI
Network
ISDN BRI
Promptus
3BRI- IMUX
21
What do you need for ATM?
ATM
Network
ATM-25
384KB - 1472KB
ATM25
NIC
22
What do you need for IP Video?
Ethernet
Network
Ethernet
NIC
23
Role of the MCU
• MCU - Multipoint Control Unit (Multipoint Bridge)
• People start with Point-to-Point, then experience
leads to Multipoint
• When Multipoint service is available, 40-85% of all
videoconferences are multipoint
• Audio Conferencing, Video Switching, Data
Transfer
• Conference Setup and Control
• Voice activated, chairperson control or
continuous presence
24
Advanced Video Capabilities
• Record video clip on disk
– Video mail
• MPEG-1/MPEG-2 viewing and “Store & Forward”
• Cable TV interface/Broadcast
• Connectivity Options
– Multirate ISDN (384Kb)
– ATM
– Dialable Wideband
– IP-based
• Remote Camera Support
25
Benefits of Multimedia Conferencing
•
•
•
•
•
•
•
•
•
•
•
•
Faster and Better Decision Making
Increased Productivity
More Meetings
Tighter Security
Improved Employee Morale
Avoided Travel Costs
Reduced Fatigue
Efficient Use Of Key Personnel
More Disciplined, Productive Meetings
Team Building
Interning
Reliability
26
Thank You !