Unequal packet loss resilience for fine-granular-scalability video
Several embedded video coding schemes have been recently developed for multimedia streaming over IP. In particular, fine-granular-scalability (FGS) video coding has been recently adopted by the MPEG-4 standard as the core video-compression method for streaming applications. From its inception, the FGS scalability structure was designed to be packet-loss resilient especially under unequal packet-loss protection (UPP). However, since the introduction of FGS, there has not been a comprehensive study evaluating its packet-loss resilience under unrecoverable packet losses that are common in Internet streaming applications. In this paper, we evaluate two important aspects of FGS packet-loss resilience. First, we study the impact of applying UPP between the base- and enhancement-layers on FGS-based streams, and we compare equal packet-loss protection (EPP) with UPP scenarios. Second, we introduce the notion of fine-grained loss protection (FGLP), which is suitable for the FGS enhancement-layer, and we develop an analytical framework for evaluating FGLP bounds. Based on these bounds, we show the impact of applying fine-grained protection to the FGS enhancement-layer for different types of video sequences and over a wide range of bit-rates and packet-loss ratios. As illustrated by our extensive simulation results, applying 1) UPP between the base- and enhancement-layers and 2) FGLP for the FGS enhancement-layer can provide significant resilience under moderate-to-high packet-loss ratios (e.g., 5-10%). Furthermore, the merits of this new packet-loss protection technique go beyond the FGS coding scheme, because FGLP can be successfully applied to improve the resilience to packet-losses of other embedded video coding techniques.