A Performance Study of Adatptive Video Coding Algorithm;s for High Speed Networks

Adaptive video coding algorithms are digital video compression algorithms that can adapt the encoding of a video stream dynamically based on the amount of bandwidth available on the network. While such algorithms are more complicated than traditioncil video coding algorithms, they are attractive because #of their inherent robustness to changes in network load (i.e., network congestion). Adaptive video coding algorithins seem particularly suitable for high speed network. environinentCs, such as B-ISDN/ATM, that offer A,uailable Bit Rate (ABR) services. The goal of this paper is to assess the role that adaptive video coding algorithms will play in future high speed networks. The paper presents a simple mathematical model and analysis of several hypothetical video coding algorithms for high speed netwonks, and a simulation study of one such adaptive video coding algorithm that we have implemented in a local area network environment. The results show that adaptive video coding algorithms are indeed robust across a wide range of network loads. More itnportantly, however, the results suggest that the domain of adaptive video coding algorithms is quite narrow: moderately to heavily loaded networks with speeds on the order of 10 Mbps a.nd 100 Mbps. As a result, adaptive video coding algorithrns will likely play only a lirnited role in future high speed networks.