Efficient Algorithm for Globally Optimal Uneven Erasure-Protected Packetization of Scalable Code Streams

A new algorithm is presented for rate-fidelity optimal packetization of scalable source bit streams with uneven erasure protection. It provides the globally optimal solution for input sources of convex rate-fidelity function and for a wide class of erasure channels, including channels for which the probability of losing n packets is monotonically decreasing in n, and independent erasure channels with packet erasure rate smaller than 0.5. The time and space complexities of the new algorithm are both O(NL), where N is the number of packets and L is the packet payload size, comparing to the O(NL² ) time and space complexities of the existing globally optimal solution. When applied to SPIHT compressed images, the results of the proposed algorithm are virtually the same as the globally optima