Bandwidth efficient mobile cloud gaming with layered coding and scalable phong lighting

In mobile cloud gaming, one of the main challenges is to deliver high-quality game images over wireless networks under stringent delay requirement. To reduce the bit-rate of game images, we propose Layered Coding, which leverages the graphic rendering capability of modern mobile devices to reduce transmission bit-rate. Specifically, we render a low-quality local game image, or the base layer, on the power-constrained mobile client. Instead of sending the high quality game image, the cloud server sends enhancement layer information, which the client utilizes to improve the quality of the base layer. Central to the proposed layered coding is the design of base layer (BL) rendering. We discuss BL design and propose a computationally-scalable Phong lighting that can be used in BL rendering. We performed experiments to compare our layered coding with state-of-the-art, which uses H.264/AVC inter-frame coding to compress game images. With game sequences of different model complexity and motion, our results suggest that layered coding requires substantially lower data-rate. We made available game video test sequences to stimulate future research.