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

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

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

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, -1) > Threshold) : Minimize Lagrangian Cost Function

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

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

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

Proposed Experiment DCT MC IDCT ME Frame Memory 1 Input Video Intra IQ 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

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

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

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