Error-Resilient Video Coding

Abstract

If source coding removes all the redundancy between the source symbols and achieves entropy, a single error occurring at the source will introduce a great amount of distortion. In other words, ideal source coding is not robust to channel errors. In addition, designing an ideal or near-ideal source coder is complicated, especially for video signals, because video signals are time varying and have memory, and their statistical distribution may not be available during encoding (especially for live video applications). Thus, redundancy certainly remains after source coding. Rather than aiming at removing the source redundancy completely, we should make use of it. On the other hand, as mentioned in Chapter 3, we understand that the nature of JSCC is to optimally add redundancy at both the source- and channel-coding levels. Thus we need to regard the remaining redundancy between the source symbols after source coding as an implicit form of channel coding [94]. Actually, when JSCC is involved, source coding and channel coding sometimes can hardly be differentiated.