Optimal erasure protection for scalably compressed video streams with limited retransmission on channels with IID and bursty loss characteristics

In this paper we combine priority encoding transmission (PET) with a limited retransmission (LR) capacity. We propose the resulting LR-PET scheme as a framework for efficient RD optimized delivery of streaming media. Previous work on scalable media protection with PET has largely ignored the possibility of retransmission. In the proposed LR-PET framework, an optimization algorithm determines the level of protection for each element in each transmission slot, subject to transmission bandwidth constraints. To balance the protection assigned to elements being transmitted for the first time with those being retransmitted, the proposed algorithm formulates a collection of hypotheses concerning its own behavior in future transmission slots. We show that this formulation of hypotheses is central to the success of the proposed LR-PET algorithm. Indeed, without this element, a greedy version of LR-PET performs only slightly better than PET without retransmission. Experimental results are reported using both IID and GE channel models, with a Motion JPEG2000 video source, demonstrating substantial performance benefits from the proposed framework.