  Cloud gaming enables playing high end games, originally designed for PC or
game console setups, on low end devices, such as net-books and smartphones, by
offloading graphics rendering to GPU powered cloud servers. However,
transmitting the high end graphics requires a large amount of available network
bandwidth, even though it is a compressed video stream. Foveated video encoding
(FVE) reduces the bandwidth requirement by taking advantage of the non-uniform
acuity of human visual system and by knowing where the user is looking. We have
designed and implemented a system for cloud gaming with foveated graphics using
a consumer grade real-time eye tracker and an open source cloud gaming
platform. In this article, we describe the system and its evaluation through
measurements with representative games from different genres to understand the
effect of parameterization of the FVE scheme on bandwidth requirements and to
understand its feasibility from the latency perspective. We also present
results from a user study. The results suggest that it is possible to find a
"sweet spot" for the encoding parameters so that the users hardly notice the
presence of foveated encoding but at the same time the scheme yields most of
the bandwidth savings achievable.
