Scalable Multiple Description Coding for Video Distribution in P2p Networks

In this paper we present and evaluate a method for video distribution through a peer-to-peer (P2P) network using Multiple Description Coding in a multicast tree. Our method solves the problem of serving many clients with heterogeneous bandwidths. Every node forwards descriptions to other nodes. Nodes that have sufficient bandwidth are then able to receive more descriptions, and thereby to increase the quality. We use a combination of a layered video codec and erasure coding to generate multiple descriptions. Given different client-bandwidth distribution functions, we optimize a fairness criterion such as the (average) quality for all clients. Since we optimize the average quality for all clients as a group, the performance for individual clients may be very different. We discuss the reduction in quality for clients that have bandwidths other than average as opposed to a single description stream. Finally, we discuss the efficiency, in terms of bit rate and redundancy, for all clients as a group, and individually.