Multiple Description Coding For The Reliable Transmission Of Compressed Digital Video

Over packet switched networks, the noise disturbance, network congestion, etc. will all lead to packet loss and burst errors. In these cases, the quality of the decoded video will degrade severely and the carrying video service can't go on normally. Therefore, the reliable transmission of the compressed video over networks and wireless channels has been much attention. Multiple Description Coding (MDC), an important source coding method that enables the reliable video transmission, can protect video against burst disturbance and has good performance of error concealment and error resilience. Based on the previous research achievements on MDC, this paper does further researches on the effective methods of MDC.First, through the analysis of the MDC algorithm based on Pairwise Correlating Transform (PCT), a MDC framework based on PCT is realized on the basis of the H.263 standard . In the simulation, the redundancy-rate-distortion performance is analyzed, and results prove that this MDC has a better reconstruction performance than conventional single description coder (SDC) in error-prone environments.Second, an analysis of the algorithm of the MDC of Motion Fields based on the Overlapped Block Motion Compensation (OBMC) is further done in this paper. By applying the algorithm of the MDC of Motion Fields to H.263 standard, a framework of MDC of Motion fields is realized. The simulation results show that, compared with conventional single description coder, this algorithm can improve the subjective and objective performance in the environment with more errors.Finally, the above two algorithms are combined, and a new completed multiple description video coding framework is proposed. In the simulation, its redundancy-rate-distortion performance is analyzed firstly, then the performance of error concealment and error resilience, the coding framework proposed in this paper are tested and compared with the MDC based on PCT and SDC in error-prone environments, the results testify that not only the proposed MDC scheme has a better robustness but also a higher coding efficiency, which ensures reliable transmission of compressed digital video over networks.