Software Labs

In this paper, design and implementation of a dynamic power management for a MPEG-4 player is described. We designed two dynamic voltage scaling algorithms (feedback-based and buffering-based) to adapt CPU voltage dynamically according to the variable bit rate of a movie. We experimented the algorithms with the open-source XviD player. Our modified XviD player can save up to about 50 % power without performance degradation. We describe practical lessons learned in optimization of the algorithms. Power management (PM) is an important issue for battery-powered Linux devices, particularly for video playing devices. Our work shows how a conventional open-source video player can be modified to save power significantly on a CPU with dynamic voltage scaling ca-pability.