Wireless FGS video transmission using adaptive mode selection and unequal error protection Jianhua Wu and Jianfei Cai Nanyang Technological University Visual Communications and Image Processing 2004

Outline Introduction  MC-FGS  Unequal Error Protection Mode Adaptive FGS Architecture (MA-FGS) UEP for FGS End to End Distortion R-D Extraction of FGS coding Experimental Result Conclusion

Introduction Wireless video transmission becomes possible and has received more and more attention Huge data size of digital video and limited bandwidth of wireless channels Highly efficient video coding schemes and severe error environment Video coding rate can be adaptively adjusted

Introduction (cont.) Scalable video coding is a common approach for providing rate adaptation. The FGS enhancement layer bitstream can be truncated at any position There is no prediction in the FGS enhancement layer FGS is not fit the limited bandwidth of wireless networks

FGS - Improvement MC-FGS I B P B P Error Propagation occurs while losing the referenced enhancement layer

Unequal Error Protection Using Error control techniques (FEC etc.) to transmit FGS bitstream over packet loss channels This paper jointly consider mode selection and UDP for FGS video transmission over wireless channels  With prediction or without prediction

MA-FGS PSNR performance

MA-FGS: Structure Mode-Adaptive FGS Architecture

MA-FGS : Symbols

MA-FGS I-FGS: an FGS enhancement layer frame coded without prediction P-FGS: with prediction  Apply the motion vectors generated in the base layer

UEP for FGS k

Problem Formulation Let  {0,1} be the mode decision for FGS enhancement layer frame, where  = 0 means I-FGS while  = 1 means P-FGS  D =  D I + (1-  )D P Problem: Given a total bandwidth and channel symbol rate , how to choose  and l to minimize the distortion D = D s + D c

End to end Distortion Distortion of I-FGS

End to end Distortion (cont.) Distortion of P-FGS

End to end Distortion (cont.) Final formulation

R-D Extraction R-D Extraction of FGS Source Coding

Experimental Result Bitrate and PSNR

Experimental Result Error Rate and PSNR

Conclusion This paper proposed a MA-FGS system structure, and perform experiments to illustrate the effectiveness It has derived an overall end-to-end R-D function for the proposed system