Adaptive Error-Resilience Transcoding and Fairness Grouping for Video Multicast Over Wireless Networks

In this paper, we present a two-pass intra-refresh transcoder for on-the-fly enhancing error resilience of a compressed video in a three-tier streaming system. Furthermore, we consider the problem of multicasting a video to multiple clients with diverse channel conditions. We propose a MINMAX loss rate estimation scheme to determine a single intra- refresh rate for all the clients in a multicast group. For the scenario that a quality variation constraint is imposed on the users, we also propose a grouping method to partition a multicast group of heterogeneous users into a minimal number of sub-groups to minimize the channel bandwidth consumption while meeting the quality variation constraint and achieving fairness among all sub-groups. Experimental results show that the proposed method can effectively mitigate the error propagation due to packet loss as well as achieve fairness not only among all sub-groups and also clients in a multicast group.