Towards an energy-efficient attention-aware mobile video player with sensor and face detection support

When watching video in a mobile environment, many distractions can draw the attention of the user away from the terminal, e.g., a smartphone. The power consumed by the phone during video playback is wasted in case the user is not watching. In this paper, we present an interactive video player allowing to temporarily interrupt the playback when the user is looking away, and resume it when the user starts looking at the phone again. In order to detect user inattention, we exploit the front-facing camera embedded in most current smartphones as image source for face detections. We analyze the power consumption of the phone when running our interactive video player in controlled and realistic scenarios, and study the energy savings induced by the attention-aware playback interruption. Additionally, we study the influence of video bitrate and content on power consumption. Finally, we propose a cloud-based approach in which the image captured by the front camera is sent to a server, which performs the face detection. We show that the power savings are significant using this approach, and can compensate the consumption added by the increased wireless traffic.