Subjective evaluation of Hierarchical B-Frames using Video-MUSHRA

Hierarchical B-Frames (HBF) has emerged as an efficient video coding tool in recent years. As shown in the literature, this approach results in excellent PSNR gains of >1 dB. However these PSNR gains are not sufficiently assessed in a scientific manner by subjective tests. Hence in this paper, we evaluate HBF coding pattern subjectively by using the MUSHRA test methodology. While MUSHRA is well established in audio coding research, its application to video is a novelty of this paper. We compare HBF with simple IPP coding pattern at either same PSNR or same bit rate. Our results indicate that, HBF gains are clearly subjectively perceptible. Hence, it can be shown that PSNR gains also correlate with a subjective gain. Interestingly, even at same PSNR, HBF is found to be subjectively superior to simple IPP coding.