Unequal Loss Protection Using Layer-Based Recovery Rate (ULP-LRR) for Robust Scalable Video Streaming over Wireless Networks

Abstract

Recently, a variety of multimedia services like video streaming over wireless networks have emerged [1]. However, consecutive packet losses and rapid bandwidth changes in wireless environments cause serious video quality degradation.The most promising mechanism for the wireless transmission of H.264 video is scalable video coding (SVC), which is a highly attractive solution to the problems posed by the properties of wireless video transmission. A scalable video can provide spatial, temporal, and quality scalabilities without any additional computational load. A scalable bitstream allows different video qualities and resolutions for different video receivers according to the characteristics of the transmission channel or the decoding capability of the receiver. It is possible to transmit and decode partial bit streams to support video services with lower temporal or spatial resolutions or reduced fidelity while retaining a reconstruction quality that is high relative to the rate of the partial bit streams. Hence, H.264/SVC provides functionalities such as graceful degradation in lossy transmission environments as well as the possibility for bit rate adaptations [2,3]. However, due to the spatial and temporal dependencies among scalable video layers, consecutive packet losses may lead to a serious degradation This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/bync/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. AbstractScalable video streaming over wireless networks has many challenges. The most significant challenge is related to packet loss.To overcome this problem, in this paper, we propose an unequal loss protection (ULP) method using a new forward error correction (FEC) mechanism for robust scalable video streaming over wireless networks. For an efficient FEC assignment considering video quality, we first introduce a simple and efficient performance metric, the layer-based recovery rate (LRR), for quantifying the unequal error propagation effects of the temporal and quality layers on the basis of packet losses. LRR is based on the unequal importance in both the temporal and the quality layers of a hierarchical scalable video coding structure. Then, the proposed ULP-LRR method assigns an appropriate number of FEC packets on the basis of the LRR to protect the video layers against packet lossy network environments. Compared with conventional ULP algorithms, the proposed ULP-LRR algorithm demonstrates a higher performance for various error-prone wireless channel statuses.