Error-resilient transcoding for video over wireless channels

摘要

We describe a method to maintain quality for video transportednover wireless channels. The method is built on three fundamental blocks.nFirst, we use a transcoder that injects spatial and temporal resilienceninto an encoded bitstream. The amount of resilience is tailored to thencontent of the video and the prevailing error conditions, asncharacterized by bit error rate. Second, we derive analytical modelsnthat characterize how corruption propagates in a video that isncompressed using motion-compensated encoding and subjected to bitnerrors. Third, we use rate distortion theory to compute the optimalnallocation of bit rate among spatial resilience, temporal resilience,nand source rate. Furthermore, we use the analytical models to generatenthe resilience rate distortion functions that are used to compute thenoptimal resilience. The transcoder then injects this optimal resilienceninto the bitstream. Simulation results show that using a transcoder tonoptimally adjust the resilience improves video quality in the presencenof errors while maintaining the same input bit rate