1. Optimal Mode Selection For Robust Video Transmission
EE368C Project Proposal
Stanford University
Sangoh Jeong
Feb.1, 2001

2. Outline Goals Existing Mode Decision Processes
R-D Based Mode Selection
Proposed New Coding Mode
Proposed Experiment
Project Schdule

3. Goals Optimal Switching of Coding Modes
Proposes an additional coding mode
Considers the trade-off between coding efficiency and error resiliency
Improves PSNR characteristic in error-prone environment
Uses an intelligent encoder without feedback
Decides the optimal mode with moderate complexity

4. Mode Decision Processes
Low Complexity Mode Selection
Error-Free Environment
Error-Prone Environment
High Complexity Mode Selection
: Intra mode if (A < (SAD(x,y) – 500))
: Intra mode if (E(mb, ) > Threshold)
: Minimize Lagrangian Cost Function

5. Lagrangian Cost Function
D : SSD between the original MB and its Rec.
R : bitrate associated with choosing Mode
Rate R
Lines of constant J
Distortion D

6. Proposed Mode Selection
Cost Function of Each Mode
Intra Mode
Inter Mode
In-Between Mode
Value of
Choose the Mode which has the mimimum .

7. Operation Of In-Between Mode
Prediction Error
Leaky Prediction
Attenuates the energy of the prediction signal
Superimposed errors decay over time
Intra perfect, Inter weak
MCed Frame
Intra Frame
MB2
MB1

8. Proposed Experiment DCT MC IDCT ME Frame Memory 1 Input Video IntraIQ MC
(Interpolator) + Q
IDCT ME
Frame
Memory 1
Current MB
Local Memory
Search
Area MV
Input
Video
Intra
Inter
Coding Control IQ
IDCT
Error
Insertion
Frame
Memory 2

9. Experiment Conditions
Types of Trasmission Errors to be used
Burst Errors
: Random loss of 1 GOB in every two frame
Random Bit Errors
: Randomize 5% of bits in each frame
Encoder Software to be used
H.263+ (tmn10) encoder
Mode decision
- Low Complexity : Uses threshold
- High Complexity : Uses Lagrangian cost function

10. Expected Result PSNR(dB) Expected result of the proposal
Two-mode switching
time(s)
Loss in signal-to-noise ratio of decoded video signal after errors happen

11. Project Schdule 1st 2nd 3rd 4th 5th R-D Theory 3-Mode Simulation Week
Month
February
March
Software Test
2-Mode
Simulation
Intermediate
Documentation
R-D Part Design
Final Report
Presentation