C2: ABR Streaming in Cognizant of Consumption Context for Improved QoE and Resource Usage Tradeoffs

Abstract

Smartphones have emerged as ubiquitous platforms for people to consume content in a wide range of consumption contexts (C2), e.g., over cellular or WiFi, playing back audio and video directly on phone or through peripheral devices such as external screens or speakers. In this paper, we argue that a user’s specific C2 is an important factor to consider in Adaptive Bitrate (ABR) streaming. We examine the current practices of using C2 in five popular ABR players, and identify various limitations in existing treatments that have a detrimental impact on network resource usage and user experience. We then formulate C2-cognizant ABR streaming as an optimization problem and develop practical best-practice guidelines to realize it. Instantiating these guidelines, we develop a proof-of-concept implementation in the widely used state-of-the-art ExoPlayer platform and demonstrate that it leads to significantly better tradeoffs in terms of user experience and resource usage. Last, we show that the guidelines also benefit dash.js player that uses an ABR logic significantly different from that of ExoPlayer.