Comparative Analysis and Performance Evaluation of Adaptive 360° Video DASH Streaming Solutions

We explore two competitive viewport-adaptive 360° video streaming methods: Quality Emphasized Region (QER) representations and 360° panorama Tiling, across multiple performance factors. We carry out our analysis and evaluation within the context of the MPEG Dynamic Adaptive Streaming over HTTP (DASH) standard. The performance criteria we use in our analysis include delivered video quality (PSNR, VMAF), encoding and decoding time/complexity per video frame, and required storage. We also formulate analysis for immersive quality optimization in both streaming systems. Our comprehensive experimental evaluation provides valuable insights for streaming platforms and service operators aiming to optimize the viewer experience while achieving high system efficiency. In particular, we show that Tiled streaming provides 35% lower encoding bitrate and 52% lower encoding time. However, QER streaming can offer significant advantages in reducing the induced decoding complexity/time by approximately 38% while enabling 0.9-1.7 dB higher viewport quality on average and also 2.5-3 dB higher quality in optimal rate allocation scenario, resulting in smoother video playback and higher quality of viewing experience. Additionally, QER streaming demonstrates superior video quality performance in longer video segments by effectively covering larger areas of the video. Specifically, by increasing the video segment duration from 1 second to 8 seconds, the QER method shows an average 0.5 dB improvement in quality performance compared to the tiled method.