Perceptual Sensitivity to Video Degradations in a Simulated Cloud-Gaming Environment: An Empirical Study through Subjective Tests

Sammanfattning: Cloud gaming, often referred to as gaming on demand or game streaming, is a contemporary form of online gaming. It operates by running video games on powerful, remote servers and streaming them in realtime directly to a user’s device. In contrast to the traditional gaming model where a game is executed locally on a user’s video game console, personal computer, or mobile device, cloud gaming allows users to experience high-quality graphics on any device, without being constrained by the device’s performance.  As cloud gaming services rise in popularity, understanding the impact of sudden video degradations on user experience becomes crucial. While some studies have investigated the influence of overall video quality on these platforms, the aspect of users’ sensitivity to abrupt video quality declines has remained relatively unexplored. Hence, Ericsson in Luleå conducted this research to probe into user perceptions of such video degradations through an interactive testing approach.  The interactive test incorporates a purposefully designed program that simulates a cloud-gaming environment, where rendered game frames are captured and processed through an encoder/decoder pair, intentionally inducing video degradations. This unique setup effectively replicates the cloud gaming experience while additionally provides explicit control over the video compression technique. Participants interacted with the game under varying conditions of degradation severities and durations, after which they provided feedback through a questionnaire.  Subsequent comprehensive analysis of the collected data provided insight into users’ sensitivity towards video degradations. As might be expected, sensitivity largely depends on the severity and duration of the degradations. In other words, the more severe and prolonged the degradation, the more likely it is to be perceived. Interestingly, about two-thirds of the participants displayed relative insensitivity to most of the test conditions, indicating a potential threshold of perception for video degradation in cloud gaming. A smaller subset of participants, notably those proficient at the game tested, exhibited substantially higher sensitivity. These findings carry some helpful implications for the cloud gaming industry, highlighting the importance of managing video quality for optimal user experience. They also pave the way for further research into the user variability in perception of video degradation.