Research On Multiple Description Coding

Recently, the problem of packets loss and errors in video communication over erasure channels becomes an important topic. As a result, multiple description coding is proposed as an efficient scheme to address this problem. Multiple description coding is able to improve the robustness, and ensure real-time transportation over unreliable channel for multimedia data. This paper researches on several schemes of multiple description coding which are widely used in practical application. In combination with the thought of differential treatment and the specific feature of Uniform Tight Frame, previous schemes of multiple description coding have been improved in this dissertation. The main contribution of this paper is as following:Firstly, multiple description coding is introduced after the presentation about evolution of source coding. Rate-distortion function in Information Theory of MDC, multiple description image coding and multiple description video coding are surveyed in detail. Then the development trends of MDC are present.One kind of standard-compatible multiple description image coding using space expansion and poly-phase down-sample methods is analyzed, and there are different performances under certain rate. The thought of differential treatment is used to improve the performance, so ROI that comes from JPEG2000 standard is present to combine with this scheme, and the effectiveness of the method is certified.Furthermore, we propose a scalable multiple description coding scheme based on frame expansion. For one hand, uniform tight frame owns attractive features; for another hand, the diversity of network structure and terminal equipment exist in real world. The frame used here is Harmonic Frame, which is a sort of uniform tight frame. The data in different layers is expanded by different scales in order to improve the performance of the whole system. Compared to FEC based MDC scheme, this scheme is suitable for the channel can't be predicted.Finally, some problems existed in this dissertation are summarized, and then the development directions of MDC are proposed.