A Subjective Comparison of AV1 and HEVC for Adaptive Video Streaming

In this paper we compare the performance of two state-of-the-art competing codecs, AV1 and HEVC, in the context of adaptive streaming. We specifically consider a Dynamic Optimizer (DO) methodology that is content-aware and selects the resolution of the video sequence after constructing the convex hull of the Rate-Quality curves of all considered resolutions. We start with an objective evaluation of the Dynamic Optimizer, based on both PSNR and VMAF quality metrics. The Rate-VMAF curves show an average of 6.3% BD-Rate gain of AV1 over HEVC, while the Rate-PSNR curves an show an average BD-Rate loss of 1.8%. We then report subjective tests which evaluate the perceived quality of the selected bitstreams generated by the two codecs. In this case it was found that, for most rate points, the difference in the perceived quality between HEVC and AV1 is not significant.