Opportunistic decoding of unequal erasure protected partially-decodable scalable source

To provide unequal erasure protection to scalable codes, a general framework has been proposed in [1] and it has become the foundation of following research in this literature. In this paper, we make opportunistic utilization of received packets under the same framework. Specifically, we extract those non-decodable original symbols in received packets by taking advantage of the joint coding structure. By regulating the scalable codes to partially-decodable scalable codes, these original symbols can be used to improve the quality of reconstructed source. Further more, we formulate the opportunistic unequal erasure protection and analyze the relationship between optimal unequal erasure protection (OP) and opportunistic optimal unequal erasure protection (OOP). Based on the analysis result, a simple algorithm is proposed to find the optimal protection which maximizes the expected quality of reconstructed source. Finally, experiment results are presented which verify the improvement of opportunistic utilization over traditional unequal erasure protection.