Reducing Power Consumption in Mobile Terminals—Video Computing Perspective

Abstract

The high power consumption of video playback in mobile terminals has two major negative impacts. It limits the available operating time of the terminal devices deteriorating the user experience and contributes to the global energy consumption with negative environmental effects. Solutions to reduce the energy usage of mobile terminals include increasing the power efficiency of the terminal components, optimizing the video decoding and playback software as well as altering the quality and/or compression settings of the video data. While there exist some studies on power consumption with these means, most of them do not apply to state-of-the-art terminal hardware nor do they take a systematic approach to evaluate all available techniques. The focus of this chapter is on reducing the power consumption of mobile terminals as a part of video delivery system. For that, a wide variety of video computing-related energy-saving techniques is presented and evaluated on a line of Apple laptop mobile terminals running publicly available video playback software. The tests are done with video clips representing different kinds of video content and the effect of terminal hardware, video coding, video quality, player software, execution-environment/parameters and streaming to power consumption and data rate is measured. According to the measurements, the video computing induced consumption, total power consumption and data rate can be reduced with respect to the state-of-the-art situation in the beginning of the research by 83%, 65%, and 43%, respectively. Additional reductions can be achieved by decreasing the quality of videos, switching to smaller footprint devices, and replacing the current processors with more advanced ones.