Improving the error resilience of H.264/SVC over IP networks

Abstract

Internet based video services are on the increase thanks to the introduction of IPTV, Video On Demand and other video based services such as videoconferencing and video sharing. This increase in video traffic is expected to surpass the 70% mark of global Internet traffic by the end of 2014, thus making video transmission efficiency in term of bandwidth usage more important. H.264/SVC is the video codec chosen in this paper. This video codec transmits video data in layered bitstreams, providing the possibility of an efficient bandwidth usage in a heterogeneous environment. The layered bitstreams consist of a base layer and enhancement layers, which are structured in a hierarchical manner, where the layers at the top of the hierarchy have dependencies on the lower layers. This makes the base layer critical for the succesful reconstruction of the video stream, hence protecting the base layer should be given the highest priority in a network. Therefore, given this requirement, an Unequal Error Protection scheme which makes use of a K-Shortest Path algorithm is presented. This UEP scheme attempts to find the optimal/shortest route in the network to the base layer. The remaining SVC layers are then assigned routes with increasing cost i.e the higher the layer in the hierarchy, the higher the cost of the route assigned to it.