Complexity-scalable video coding and power-rate-distortion modeling forwireless video chat applications

Wireless video chat is a power-consuming and of high bitrate application. To prolong the operational lifetime, optimal rate and power allocations in joint coding and transmission are necessary. We exploit low motion and high inter-frame correlation in video chats to determine a complexity-scalable video coding adaptation which is Pareto optimal. We propose a model that describes power-rate-distortion (PRD) characteristic of the complexity scalable video coding more accurately. As video contents are non-stationary, we formulate an online algorithm for the model´s parameters updates. We demonstrate that the PRD model with online updates can be applied to solve the rate and power allocation problem optimally in joint coding and transmission. Simulation results confirm that the model describes PRD characteristics more accurately via online recursive updates. The resource allocation scheme which is based on the PRD model yields better video quality than recent methods in a resource-constrained wireless video chat application.