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Basic foilset Multiplatform Desktop Videoconferencing System for Internet

Given by Tom Stachowiak at Defense of 5 CIS Master's Theses on Dec 15 1997. Foils prepared April 13 98
Outside Index Summary of Material

Multimedia technologies
  • compression
  • standards
Existing products overview
Design and implementation
  • system objectives
  • architecture
  • components description
Conclusions

Table of Contents for full HTML of Multiplatform Desktop Videoconferencing System for Internet

 Denote Foils where Image Critical
Denote Foils where HTML is sufficient
1 Videoconferencing System
2 Videoconferencing System Presentation Outline
3 Technology Data Compression
4 Technology Audio Compression
5 Technology Audio Compression
6 Technology GSM Audio Compression
7 Technology Video Compression
8 Technology H.261 Video Compression
9 Technology H.263 Video Compression
10 Technology Multimedia standards
11 Technology Multimedia standards
12 Technology Multimedia standards
13 Videoconferencing Products Summary
14 Design and Implementation System Objectives
15 Design and Implementation System Architecture
16 Design and Implementation System Architecture
17 Design and Implementation System Architecture
18 Design and Implementation System Architecture
19 Design and Implementation System Architecture
20 Design and Implementation System Architecture
21 Design and Implementation Conference Applications
22 Design and Implementation Audio Tool
23 Design and Implementation Video Tool
24 Design and Implementation Video Tool
25 Design and Implementation Directory Service
26 Design and Implementation Archiving
27 Design and Implementation Other issues
28 Design and Implementation Web Integration
29 Conclusions System Advantages
30 Conclusions System Advantages
31 Conclusions Disadvantages and Future Work

Outside Index Summary of Material

HTML version of Basic Foils prepared April 13 98

Foil 1 Videoconferencing System

From Multiplatform Desktop Videoconferencing System for Internet Defense of 5 CIS Master's Theses -- Dec 15 1997. *
Full HTML Index
Master's Thesis
Tomasz Stachowiak
HTML version of Basic Foils prepared April 13 98

Foil 2 Videoconferencing System Presentation Outline

From Multiplatform Desktop Videoconferencing System for Internet Defense of 5 CIS Master's Theses -- Dec 15 1997. *
Full HTML Index
Multimedia technologies
  • compression
  • standards
Existing products overview
Design and implementation
  • system objectives
  • architecture
  • components description
Conclusions
HTML version of Basic Foils prepared April 13 98

Foil 3 Technology Data Compression

From Multiplatform Desktop Videoconferencing System for Internet Defense of 5 CIS Master's Theses -- Dec 15 1997. *
Full HTML Index
Reduction of the amount of allocated space
Two basic classes of compression
  • redundancy reduction - does not introduce distortions
  • entropy reduction - information losses
Standard algorithms are not efficient for audiovisual signals
HTML version of Basic Foils prepared April 13 98

Foil 4 Technology Audio Compression

From Multiplatform Desktop Videoconferencing System for Internet Defense of 5 CIS Master's Theses -- Dec 15 1997. *
Full HTML Index
Adaptive Differential Pulse Code Modulation (ADPCM)
  • lower variance of difference between samples
  • linear prediction
  • locally stationary audio signals
  • adaptive corrections to prediction coefficients
  • minimizing the Mean Square Error (MSE)
HTML version of Basic Foils prepared April 13 98

Foil 5 Technology Audio Compression

From Multiplatform Desktop Videoconferencing System for Internet Defense of 5 CIS Master's Theses -- Dec 15 1997. *
Full HTML Index
GSM speech compression
  • cellular telephony standard
  • designed specifically for the speech signals
  • based on Long-Predictive Coding (LPC)
  • modeling of the human vocal tract with an adaptive filter
  • transmitted data:
    • filter coefficients
    • general characteristics of the signal(e.g. gain, lag)
    • residual pulse excitation
HTML version of Basic Foils prepared April 13 98

Foil 6 Technology GSM Audio Compression

From Multiplatform Desktop Videoconferencing System for Internet Defense of 5 CIS Master's Theses -- Dec 15 1997. *
Full HTML Index
HTML version of Basic Foils prepared April 13 98

Foil 7 Technology Video Compression

From Multiplatform Desktop Videoconferencing System for Internet Defense of 5 CIS Master's Theses -- Dec 15 1997. *
Full HTML Index
ITU-T H.261 algorithm
  • Discrete Cosine Transform (DCT) coding technique
  • uses two video compression methods
    • spatial redundancy removal (every frame)
    • temporal redundancy removal (INTER frames)
  • two types of frames
    • INTRA - coded independently
    • INTER - predicted coding based on the previous frame
HTML version of Basic Foils prepared April 13 98

Foil 8 Technology H.261 Video Compression

From Multiplatform Desktop Videoconferencing System for Internet Defense of 5 CIS Master's Theses -- Dec 15 1997. *
Full HTML Index
Bitstream structure
Motion vector search
  • full spiral search
  • logarithmic search
INTRA frame coding
HTML version of Basic Foils prepared April 13 98

Foil 9 Technology H.263 Video Compression

From Multiplatform Desktop Videoconferencing System for Internet Defense of 5 CIS Master's Theses -- Dec 15 1997. *
Full HTML Index
Modified version of H.261
Improvements:
  • half-pixel motion vector prediction
  • modified Variable Length Coding (VLC) tables
  • negotiable options
    • unrestricted motion vector
    • advanced prediction
    • arithmetic coding instead of VLC
    • PB-frames
HTML version of Basic Foils prepared April 13 98

Foil 10 Technology Multimedia standards

From Multiplatform Desktop Videoconferencing System for Internet Defense of 5 CIS Master's Theses -- Dec 15 1997. *
Full HTML Index
Data transmission standards
  • Real-Time Protocol (RTP)
    • designed for the audiovisual data
    • does not guarantee quality of service
    • functionality:
      • payload type identification
      • sequence numbering
      • timestamping
      • delivery monitoring
    • augmented by RTCP
      • loosely coupled conference control
      • data transmission reports
HTML version of Basic Foils prepared April 13 98

Foil 11 Technology Multimedia standards

From Multiplatform Desktop Videoconferencing System for Internet Defense of 5 CIS Master's Theses -- Dec 15 1997. *
Full HTML Index
Session control standards I
  • ITU-T H.323
    • defines visual telephone system components:
      • terminals
      • gateways
      • gatekeepers
      • multipoint controllers
      • multipoint processors
      • multipoint control units
    • specifies control protocols:
      • H.245 - control functions
      • H.225 - channels definitions
HTML version of Basic Foils prepared April 13 98

Foil 12 Technology Multimedia standards

From Multiplatform Desktop Videoconferencing System for Internet Defense of 5 CIS Master's Theses -- Dec 15 1997. *
Full HTML Index
Session control standards II
  • ITU-T T.120
    • series of recommendations defining multipoint data conference
      • session establishment
      • participants identifications and capabilities exchange
      • communication channels management
    • layered structure
      • multipoint communication service (MCS)
      • generic conference control (GCC)
      • generic application template
      • node controller
HTML version of Basic Foils prepared April 13 98

Foil 13 Videoconferencing Products Summary

From Multiplatform Desktop Videoconferencing System for Internet Defense of 5 CIS Master's Theses -- Dec 15 1997. *
Full HTML Index
Disadvantages:
  • single platform
  • point-to-point only
  • proprietary compression
  • lack of flexibility
HTML version of Basic Foils prepared April 13 98

Foil 14 Design and Implementation System Objectives

From Multiplatform Desktop Videoconferencing System for Internet Defense of 5 CIS Master's Theses -- Dec 15 1997. *
Full HTML Index
Flexibility
Interoperability
  • platform interoperability
  • implementation interoperability
Extensibility
Archiving capability
HTML version of Basic Foils prepared April 13 98

Foil 15 Design and Implementation System Architecture

From Multiplatform Desktop Videoconferencing System for Internet Defense of 5 CIS Master's Theses -- Dec 15 1997. *
Full HTML Index
Physical System Components
HTML version of Basic Foils prepared April 13 98

Foil 16 Design and Implementation System Architecture

From Multiplatform Desktop Videoconferencing System for Internet Defense of 5 CIS Master's Theses -- Dec 15 1997. *
Full HTML Index
Logical System Structure
HTML version of Basic Foils prepared April 13 98

Foil 17 Design and Implementation System Architecture

From Multiplatform Desktop Videoconferencing System for Internet Defense of 5 CIS Master's Theses -- Dec 15 1997. *
Full HTML Index
Multipoint Communication Layer (MCL)
  • reliable multipoint channels
  • unreliable multipoint channels
Session Control Layer (SCL)
  • implemented inside the Conference Engine
  • events distribution and handling
  • conference information management
HTML version of Basic Foils prepared April 13 98

Foil 18 Design and Implementation System Architecture

From Multiplatform Desktop Videoconferencing System for Internet Defense of 5 CIS Master's Theses -- Dec 15 1997. *
Full HTML Index
RTP Layer
  • effective processing of media streams
  • providing useful information for real-time purposes
Session API
  • functions for conference creation and management
  • covers the internal manager-engine protocol
HTML version of Basic Foils prepared April 13 98

Foil 19 Design and Implementation System Architecture

From Multiplatform Desktop Videoconferencing System for Internet Defense of 5 CIS Master's Theses -- Dec 15 1997. *
Full HTML Index
Application API
  • provides useful mechanism for creating new conference application
  • developer is concerned only about the data presentation
  • important element of system extensibility
HTML version of Basic Foils prepared April 13 98

Foil 20 Design and Implementation System Architecture

From Multiplatform Desktop Videoconferencing System for Internet Defense of 5 CIS Master's Theses -- Dec 15 1997. *
Full HTML Index
Session Control Protocol (SCP)
  • conference participants management
  • conference applications management
  • maintaining additional information:
    • users directory interconnection
    • token mechanism
HTML version of Basic Foils prepared April 13 98

Foil 21 Design and Implementation Conference Applications

From Multiplatform Desktop Videoconferencing System for Internet Defense of 5 CIS Master's Theses -- Dec 15 1997. *
Full HTML Index
Audio Tool
Video Tool
Whiteboard
Text Chat
mechanisms for porting arbitrary application
HTML version of Basic Foils prepared April 13 98

Foil 22 Design and Implementation Audio Tool

From Multiplatform Desktop Videoconferencing System for Internet Defense of 5 CIS Master's Theses -- Dec 15 1997. *
Full HTML Index
Compression:
  • GSM (13 kbps)
  • ADPCM (32 kbps)
  • PCM (128 kbps)
Architecture
Half-duplex support
Streams buffering and multiplexing
HTML version of Basic Foils prepared April 13 98

Foil 23 Design and Implementation Video Tool

From Multiplatform Desktop Videoconferencing System for Internet Defense of 5 CIS Master's Theses -- Dec 15 1997. *
Full HTML Index
Compression:
  • H.263 low bandwidth, CPU intensive
  • H.261
  • H.261 intra - only INTRA frames
  • YUV9
Architecture similar to Audio Tool
Frame rate control
Formats conversion
HTML version of Basic Foils prepared April 13 98

Foil 24 Design and Implementation Video Tool

From Multiplatform Desktop Videoconferencing System for Internet Defense of 5 CIS Master's Theses -- Dec 15 1997. *
Full HTML Index
Adapting H.261/H.263 codecs
  • creating library
  • single frame procedures
  • converting I/O
  • multiple streams handling
  • inserting INTRA frame
  • performance improvement:
    • logarithmic search
HTML version of Basic Foils prepared April 13 98

Foil 25 Design and Implementation Directory Service

From Multiplatform Desktop Videoconferencing System for Internet Defense of 5 CIS Master's Theses -- Dec 15 1997. *
Full HTML Index
Active nodes monitoring
On-going sessions advertising
conference creation facilitating
protection and security
session types:
  • open
  • password protected
  • master controlled
HTML version of Basic Foils prepared April 13 98

Foil 26 Design and Implementation Archiving

From Multiplatform Desktop Videoconferencing System for Internet Defense of 5 CIS Master's Theses -- Dec 15 1997. *
Full HTML Index
Asynchronous storage mode
System integration:
  • application API
  • session API
  • engine
Database integration
HTML version of Basic Foils prepared April 13 98

Foil 27 Design and Implementation Other issues

From Multiplatform Desktop Videoconferencing System for Internet Defense of 5 CIS Master's Theses -- Dec 15 1997. *
Full HTML Index
Java API
  • extensibility feature
  • multiplatform application
  • proof of system flexibility
Session security
  • close control model
  • data confidentiality
  • directory security
HTML version of Basic Foils prepared April 13 98

Foil 28 Design and Implementation Web Integration

From Multiplatform Desktop Videoconferencing System for Internet Defense of 5 CIS Master's Theses -- Dec 15 1997. *
Full HTML Index
Tango as collaborative Java environment
BuenaVista vs. Tango
Modifications
HTML version of Basic Foils prepared April 13 98

Foil 29 Conclusions System Advantages

From Multiplatform Desktop Videoconferencing System for Internet Defense of 5 CIS Master's Theses -- Dec 15 1997. *
Full HTML Index
Multiuser
Multiplatform
Extensibility
  • modular structure
  • multilanguage support (APIs)
HTML version of Basic Foils prepared April 13 98

Foil 30 Conclusions System Advantages

From Multiplatform Desktop Videoconferencing System for Internet Defense of 5 CIS Master's Theses -- Dec 15 1997. *
Full HTML Index
Flexibility
  • several operating modes
  • bandwidth control
  • Web integration
Archiving capabilities
Interoperability
  • standard compliance
HTML version of Basic Foils prepared April 13 98

Foil 31 Conclusions Disadvantages and Future Work

From Multiplatform Desktop Videoconferencing System for Internet Defense of 5 CIS Master's Theses -- Dec 15 1997. *
Full HTML Index
Lack of full standard compliance (H.323)
Robustness
Only one session per host
Graphical User Interface (GUI)
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