A Power-Rate-Distortion Model Analysis For AVC/H.264 Encoder

With the rapid development in wireless communication, the enhancement of the wireless channel band width, and the popularity of mobile devices with multimedia data processing ability, multimedia applications in wireless environment draw great attention in the third and forth generation mobile communication. At the meantime, the processing capabilities insufficiency of mobile device compared to PC or professional equipments and the microprocessor's power-constraint problem caused by battery become the major restriction to the development of wireless multimedia applications. Sponsored by Programs of National Science Foundation of China"Complexity Scalable Power-Rate-Distortion Model for Wireless Video Communication (Grant No.60572063)"and Doctoral Foundation of Ministry of Education in China"Extended Rate-Distortion Theory and its Applications in Wireless Communication", this thesis is focusing on analyzing the power consumption behaviors of the typical video encoding system, extending power consumption as another dimension to the traditional rate-distortion analysis of video encoding system and developing a parametric power-rate-distortion analysis model which is validated by the latest H.264 JM12.0 reference software. The work aims to provide a theoretic guideline for system design and performance optimization in mobile video communication under energy constraints, and achieve the best-effort visual quality when the power level is fluctuant or limited using optimized configuration parameters.In general, the research work of this thesis could be summarized as follow:Firstly, based on the corresponding relationship between power and algorithm complexity, we clarify that the major way to control power consumption is controlling algorithm complexity. The time complexity of an algorithm is defined to represent the actual power consumption. After analyzing the main encoding modules of a typical video encoding system, we model the power consumption behaviors of these encoding modules and develop a parametric power consumption model of the H.264 encoder. We choose the bit rate and INTRA rate as the chief control parameters of this power consumption model and use the JM 12.0 video encoding reference software to encode the foreman.qcif, stefan.qcif, paris.qcif, container.qcif test sequences to validate this proposed model.Secondly, we analyze the traditional rate-distortion characters of video encoding system. After carefully picking up one good performance rate-distortion model proposed by Stuhlmiiller, we extend our proposed power consumption model to this rate-distortion model and establish a power-rate-distortion analysis framework.Thirdly, under the framework of this power-rate-distortion model, we deeply explore the relationships among the power, rate, and distortion. The discussion of the optimization of this power-rate-distortion model has also been fully presented. Using this power-rate-distortion model, the optimization of one video encoder is focusing on: find the optimized configuration parameter to achieve the best visual quality while the power consumption level is affordable; use the most suitable parameters to minimize the power consumption of video encoding while the visual quality is still acceptable.