LevelUp: A thin-cloud approach to game livestreaming

Game livestreaming is hugely popular and growing. Each month, Twitch hosts over two million unique broadcasters with a collective audience of 140 million unique viewers. Despite its success, livestreaming services are costly to run. AWS and Azure both charge hundreds of dollars to encode 100 hours of multi-bitrate video, and potentially thousands each month to transfer the video data of one gamer to a relatively small audience. In this work, we demonstrate that mobile edge devices are ready to play a more central role in multi-bitrate livestream- ing. In particular, we explore a new strategy for game livestream- ing that we call a thin-cloud approach. Under a thin-cloud approach, livestreaming services rely on commodity web infrastructure to store and distribute video content and lever- age hardware acceleration on edge devices to transcode video and boost the video quality of low-bitrate streams. We have built a prototype system called LevelUp that embodies the thin-cloud approach, and using our prototype we demonstrate that mobile hardware acceleration can support real- time video transcoding and significantly boost the quality of low-bitrate video through a machine-learning technique called super resolution. We show that super-resolution can improve the visual quality of low-resolution game streams by up to 88% while requiring approximately half the band- width of higher-bitrate streams. Finally, energy experiments show that LevelUp clients consume only 5% of their battery capacity watching 30 minutes of video.