Error Resilient Video Transmission over Wireless Networks Based on Wyner-Ziv Coding of Motion Regions
The multipath fading and shading of the wireless networks usually lead to the loss or error of video packets which results in significant video quality degradation. Existing approaches with forward error correction (FEC) or error concealment are unable to provide the desired robustness in video transmission. In this work, we develop a novel motion-based Wyner-Ziv coding (MWZC) scheme by leveraging distributed source coding (DSC) ideas for error robustness. The MWZC scheme is based on the fact that motion regions of a given video frame are particularly important to both objective and perceptual video quality and hence should be given preferential Wyner-Ziv coding based embedded protection. To achieve high coding efficiency, we determine the underlining motion regions based on a rate-distortion model. Within the framework of H.264/AVC specification, motion region determination can be efficiently implemented using Flexible Macroblock Ordering (FMO) and Data Partitioning (DP). The bit stream consists of two parts: the systematic portion generated from conventional H.264/AVC bit stream and the supplementary bit stream generated by the proposed feedback free rate allocation algorithm for Wyner-Ziv coding of motion regions. Experimental results demonstrate that the proposed scheme significantly outperforms both decoder-based error concealment (DBEC) and conventional FEC with DBEC approaches.
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