Optimal Loss-Resilient Media Streaming using Priority Encoding

A novel solution to the reliable multicast problem is the “digital fountain” approach, in which data is encoded with an erasure protection code before transmission, and receivers can recover the original data after receiving enough distinct encoded data. This solution, however, is not desirable for streaming media schemes in which it is preferable for parts of a movie to be available for consumption before the entire movie is received. Earlier work has proposed the use of Unequal Error Protection (UEP) codes, which permit some parts of the movie to be recovered before others. Unfortunately, a straightforward implementation of this solution can incur prohibitive coding complexity. We outline an on-demand media streaming scheme involving a combination of segmentation and rateless encoding. Our solution reduces the coding complexity to feasible levels, while guaranteeing the least bandwidth consumption for a given playout delay and number of segments. We propose an efficient algorithm to find the optimal segmentation for single-layered and multi-layered transmissions, and analyze its performance under network packet loss. Through analysis, numerical examples, and simulations, we demonstrate the feasibility and performance of the proposed scheme.