Buffer Control in VR Video Transmission Over MMT System

For transmitting bulky virtual reality (VR) videos efficiently, one industry-recognized mechanism is partitioning each of them into tiles and streaming the corresponding content according to user's viewport (field of view, FoV). The performance of FoV-based streaming management can be improved by FoV prediction and tiles that are prefetched by FoV prediction are stored in buffer. Buffer is of great concern to guarantee the consecutive and smooth playback throughout the whole navigation. In this paper, we design a novel VR video streaming system using MPEG Media Transport (MMT) to support tile-based transmission mechanism, considering each tile is coded at different quality levels. And the buffer model of this system is modified based on the accuracy of FoV prediction and variable bandwidth. In addition, we propose a dynamic buffer size management and the corresponding optimization method. Simulation result shows that the dynamic buffer size management have a better performance in quality of experience (QoE) than non-dynamic management.