Video kiosks increasingly contain powerful PC-like embedded processors, allowing them to display video at a high level of quality. Such video display, however, entails significant energy consumption. This paper presents an approach to reducing energy consumption by adapting the CPU frequency. In contrast to previous approaches, we exploit the specific behavior of a video kiosk. Because a kiosk plays the same set of movies over and over, our approach maintains a per-frame history of the minimum CPU frequency that suffices to treat each frame without degrading the QoS. We have implemented our approach in the legacy video player MPlayer. On a PC like those that can be found in kiosks, we observe increases in battery lifetime of up to 2 times as compared to running at maximum frequency on a set of high resolution divx movies.

HbDVS MPlayer [TAR 11 Mo]