1. Pravin Rajamoney CSE-581 Network Technology
Video Modeling
Pravin Rajamoney
CSE-581 Network Technology

2. Papers:
Analysis, Modeling and Generation of Self-Similar VBR Video Traffic. M.W.Garrentt and W.Willinger
The Correlation Structure for a Class of Scene-Based Video Models and Its Impact on the Dimensioning of Video Buffers. M.M.Krunz and A.M.Ramasamy
Hurst Parameter Estimation of Long-Range Dependent VBR MPEG Video Traffic in ATM Networks. S.H.Hong, R.Park and C.B.Lee
Simple and Efficient Models for Variable Bit Rate MPEG Video Traffic. O.Rose

3. Acronyms MPEG Moving Pictures Expert Group VBR Variable Bit Rate
CBR Constant Bit Rate
GOP Group of Pictures
ATM Asynchronous Transfer Mode
SRD Short Range Dependent
LRD Long Range Dependent

4. MPEG-2 Video Theory GOP = 12 IBBPBBPBBPBB
2 min review on
GOP = IBBPBBPBBPBB
I Picture = Intra coded pictures
P Picture = Predictive coded pictures
B Picture = Bi-directionally coded pictures

5. MPEG-2 Video Theory Field rate 2 fields per frame Frame rate
29.97 frames per second (US) NTSC
25 frames per second (Europe) PAL
Less for computers
Spatial encoding
Temporal encoding

6. CBR vs. VBR CBR video Advantage: Fluid flow video model
easier buffer management
easier on the network
Disadvantage:
Not bandwidth efficient
e.g. If average video bandwidth is 1.5Mbps, but its spike are as high as 3.5Mbps. Network must always guarantee 3.5Mbps

7. CBR vs. VBR VBR video Advantage: Bandwidth efficient Bursty
Disadvantage:
Difficult to model
Buffer management required
Data rate control required

8. Why model VBR video? Simulation
Analyze the stream for a particular network.

9. How do you make sense out of this?

10. Types of video modeling
Probability density of Gamma/Pareto model
( modified bell shape)
Scene-oriented model
Markov chain model
Histogram model (0th order Markov chain)

11. Gamma/Pareto model

12. Short Range Dependence (SRD)
Short time scale 10ms
 200 frames
Markov chain model, ARIMA process

13. Long Range Dependent (LRD)
Synonymous for “Hurst effect”
Also know as “persistence phenomena”
Observation of an empirical record being significantly correlated to observation that are far removed in time

14. Hurst value:
~ Low activity
~ ~ Medium activity
~ High activity
Hurst parameter is related to the amount of motion involved in the sequence

15. Why simulate VBR video? Calculate minimum reservation rate. R*
Amount of buffering needed in the system for it not to overflow

16. Why simulate VBR video?
BANDWIDTH
Bitrate Bandwidth utilization

17. Conclusion
LRD must be taken into consideration when modeling VBR video
VBR video is content dependent
Bandwidth and buffer size depends on the video mean bit rate
ATM systems:
Peak rate
Sustain rate
Average VBR rate
Network characterization, for real-time VBR video.