Automated adaptive playback for encoder-adjudicated live sports

Abstract

In low-latency live streaming, it is not easy to simultaneously avoid stalls and maintain low latency. The trade-off needs to be decided in real time. One of the best tools for controlling the buffer level (hence, the stalls) and live latency is adaptive playback speed control, which slows down the playback when the buffer level is critically low to reduce the risk of stalling and speeds up the playback when the buffer is sufficiently full to reduce the live latency. Adaptive playback generally works well. However, it may introduce artifacts depending on the content. Viewers may be more sensitive to playback speed changes at certain scenes. In this paper, we augment the state-of-the-art content-aware playback speed control (CAPSC) algorithm by developing a post-encoder add-on tool that analyzes the encoded live content and automatically tags each output chunk with a value indicating its suitability for playback speed changes. The source code for the CAPSC algorithm and the new post-encoder add-on (developed for the snooker games) is publicly available.