Implementing motion-constrained tile and viewport extraction for VR streaming

Abstract

1 360-degree video streaming for virtual reality (VR) is emerging. However, the computing power and bandwidth of the current VR are limited when compared to the high-quality VR. To overcome these limits, this study proposes 360 video tiled streaming method that transmits 360-degree videos using the high efficiency video coding (HEVC) and the scalability extension of HEVC (SHVC). The proposed SHVC and HEVC encoders generate the bitstream that can transmit tiles independently. The proposed extractor extracts the bitstream of the tiles corresponding to the viewport. SHVC video bitstream extracted by the proposed methods consist of (i) an SHVC base layer (BL) which represents the entire 360-degree area and (ii) an SHVC enhancement layer (EL) for selective streaming with viewport (region of interest (ROI)) tiles. When the proposed HEVC encoder is used, low and high resolution sequences are separately encoded as the BL and EL of SHVC. By streaming the BL (low resolution) and selective EL (high resolution) tiles with ROI instead of streaming whole high quality 360-degree video, the proposed method can reduce the network bandwidth as well as the computational complexity on the decoder side. Experimental results show more than 47% bandwidth reduction. © 2018 Association for Computing Machinery.