Sync Mechanism in TeraVision intern final presentation

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Sync Mechanism in TeraVisionintern final
presentation
Implementation of Seamless MPEG-4 Streaming over
Mobile IP-enabled Wireless LAN
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Contents

• Analysis of TeraVision
• The introduction of TeraVision
• Architecture of TeraVision
• Synchronization in TeraVision
• Advanced Collaborative Environments
• Thought of AG over HDV
• Cluster CAVE system in NMR room
• Future work
• Reference

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Section 1
Analysis of TeraVision
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Introduction of TeraVision

• TeraVision real-time method to distribute
  visual imagery from any PC graphics platform,
  which requires no setup, S/W, H/W changes to the
  users computer.
• Goal to provide one solution for Docking
  Problem
• It can be used to provide a means for anyone on
  the Access Grid to plug-in to deliver a
  presentation without having to install or
  configure any software, or distribute any of the
  data files, in advance.
• Useful examples
• Power pointer projector for Access Grid
• Tiled-display
• Stereoscopic system

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TeraVision System

• Hardware
• DLP projector, frame grabber ,Gigabit Ethernet
  network interface card and graphics card
• Software
• Synchronization for the multiple VBOX to display
  stereoscopic image or tiled-display
• Sufficient bandwidth is needed for cluster
• Performance
• While image streaming, be able to achieve
  approximately 29 frames per second with 500Mbps
  of network bandwidth
• Terminology
• TVserver/TVclient
• Who can get video source?
• Master/Slave
• Who can manage sync message?

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Architecture of TeraVision
Frame grabber
Projector
TeraVision CLIENT / SLAVE
TeraVision SERVER / MASTER
Display callback by OPENGL
Video source M
Common buffer
Common buffer
Get Frame
Image data
Network transmission M
Network transmission M
Control
Control
Sync client
Sync server
Sync message
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How to sync with each other
Sync Server - MASTER -
Sync Client - SLAVE -
Wait for UPDATE message
UPDATE message with frame number
Send UPDATE message
Wait for SYNC message
Receive UPDATE message
SYNC message with frame number
Send SYNC message
Receive SYNC message
TV server ? netModule
Image Data
TV client ? netModule
Note
Sync mechanism is very simple No time stamp Only
using frame number and msg. Frame lock
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How to sync with each other(cont)

• Where is the heavy load?
• Rendering
• Include loading Image
• Variable rendering powers
• Display
• Alternatives at display part in TV
• Double buffering in OpenGL
• While displaying, can render data to another
  buffer
• Re-sync before swap buffer
• Wait for other nodes, until they finalize
  rendering frame, and almost simultaneously swap
  buffer

// Frame lock with double buffering OpenGL
display callback function first sync()// wait
for display draw() Texture2D
Image() // rendering another
buffer second sync()//wait for rendering swap
buffer() refresh window()
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Section 2
ACE system (AG with CAVELib)
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The Addition of HDV into AG

• Assumptions
• High definition digital video requires abundant
  resource for decoding and display it
• Access Grid should be able to support many
  participants to communicate with each other
• Anticipated Problems
• Even though efficient network bandwidth is
  provided, the ability of one PC is limited to
  employ Access Grid over HDV with many
  participants
• Requirements
• Distributed decoding and displaying system for
  these
• Using cluster CAVElib system in NMR
• Distributed display system
• Using some architecture(?)
• Distributed decoding system

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Cluster CAVELib System in NMR
Communication message for cluster nodes
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Load balancing in cluster CAVE System?

• The answer is NO
• Every node has same graphic data
• They render the whole data
• Display range is determined by their own
  configuration files
• But this can be used for Distributed display
  system

3D walls
Display range
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Simple experiment

• Modify source code in each node
• Red ball size set 1 on master node
• Red ball size set 3 on 1st slave node
• Red ball size set 6 on 2nd slave node

Ball on master node screen
Ball on 1st slave node screen
Ball on 2nd slave node screen
size 1
size 3
size 6
lt result fig. gt
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Future work

• Synchronization in Networked Virtual Environments
• Enhance JaeHeon Jungs synchronization algorithm
• Design distributed system for AG over HDV with
  ACE team
• Focus on how to distribute decoding power,
• And if CAVE system is needed, how to connect
  distributed decoding system with cluster CAVE
  system
• Dont get discouraged by the courses for the 1st
  semester

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References

• TeraVision a Platform and software Independent
  Solution for Real Time Display Distribution in
  Advanced Collaborative Environments
• TeraVision Source code
• http//www.evl.uic.edu/cavern/optiputer/teravision
  .html
• http//www.evl.uic.edu/cavern/agave/
• CAVELib
• http//www.vrco.com/
• http//www.evl.uic.edu/pape/CAVE/prog/
• http//www.evl.uic.edu/pape/CAVE/