Study On Application Techniques Of Scalable Multiple Description Coding For Multicasting Video Over The Overlay Network

Streaming video to devices over heterogeneous network is a challenging problem, such as powerful PCs, laptops and handset devices, since different users may have different video frame rate/quality/resolution requirements, computational capabilities, and network connections. Scalable video coding and multimedia multicasting are efficient way to solve this problem. But most recent research either focus on adapting a multimedia bitstream for multiple users without applying error control methods, or focus on developing end-to-end optimization schemes to protect a progressive bitstream without multicasting, such as MD-FEC. This paper focus on scalable video streaming with fine grain adaptive forward error correction(FGA-FEC). The source bitstream are adapted in intermediate overlay nodes to satisfy heterogeneous users with both different video frame rate/quality/resolution requirements and different network connections. The main contributions are as fellows:Firstly, use Particle Swarm Optimization (PSO) to solve the stream partition problem. Experimental results show that PSO can reasonably allocate bits between source coding and channel coding, and provide close to optimal average peak signal-to-noise ratio performance and that its'running time is very low.Secondly, focus on FGA-FEC for encoding and adaptation of scalable video to diverse users when there is no congestion in the network backbone. When there is a congested backbone, we propose a scheme to identify the congested links in the backbone , running the full FGA-FEC decode/recode at the DSNs at both side of the congested link. This can reduce the computation of the whole system, and maintain the near optimal video quality.We use more bandwidth and add more protection to optimized FEC in the server or DSNs which do FEC decode/recoding, when there is still some bandwidth without streaming. This can increase the probability of receiving enough packets at DSNs, enhance the protection of bitstream.In the end, this paper summarizes all the work , and gives some suggestions of further direction of our research.