Embedded System Design and Power-rate-distortion Optimization for Video Encoding under Energy Constraints

Wireless video communication over portable devices has become the driving technology of many important applications, experiencing dramatic market growth and promising revolutionary experiences in personal communication, gaming, entertainment, military, security, environment monitoring, and more. Portable devices are powered by batteries. Video encoding schemes are often computationally intensive and energy-demanding, even after being fully optimized with existing software and hardware energy-minimization techniques. As a result, the operational lifetime of current portable video systems, such as handheld video devices, is still very short, mostly in the range of a few hours. Therefore, one of the central challenging issues in portable video communication system design is to minimize the energy consumption of video encoding so as to extend the operational lifetime of devices. In this work, we develop an operational power-rate-distortion (P-R-D) approach to minimizing the video encoding energy under rate-distortion constraints. We will demonstrate that extending the traditional rate-distortion analysis to P-R-D analysis will give us another dimension of flexibility in resource allocation and performance optimization for wireless video communication over portable devices. Theoretically, we will analyze the energy saving gain of P-R-D optimization. Practically, we will develop an adaptive scheme to estimate the P-R-D model parameters and perform on-the-