1Delay-Power-Rate-Distortion Model for Wireless Video Communication Under Delay and Energy Constraints

Smart mobile phones are capable of performing video coding and streaming over wireless networks, but are often constrained by the end-to-end delay requirement and energy supply. To achieve optimal performance under the delay and energy constraints, in this paper, we extend the traditional R-D model and the previously proposed d-R-D model to a novel delay-power-rate-distortion (d-P-R-D) model by including another two dimensions (the encoding time and encoder power consumption), which quantifies the relationship among source encoding delay, rate, distortion and power consumption for IPPPP coding mode in H.264/AVC. We have verified the accuracy of our proposed d-P-R-D model through experiments. Based on the proposed d-P-R-D model, we develop a novel rate control algorithm, which minimizes the encoding distortion under the constraints of rate, delay and power. Experimental results demonstrate the superiority of the proposed rate control algorithm over the existing scheme. Therefore, the d-P-R-D model and the model based rate control provide a theoretical basis and a practical guideline for the cross-layer system design and performance optimization in wireless video communication under delay and energy constraints