ROI-Based VR Streaming Server Tile Caching and Resolution
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Solution Overview
Problem
Virtual reality (VR) content streaming experiences delays due to viewpoint changes before final streaming and rendering to head-mounted display (HMD) devices, requiring both tracking and rendering processing at the user device and fast response from the streaming server.
Innovation Solution
An ROI-based VR content streaming server and method that employs tile caching, predicting next ROI information, and assigning different resolutions to tiles based on received ROI data to minimize delay by pre-caching and transmitting high-quality and low-quality tiles in real-time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If tracking and rendering processing is performed at the user device, then viewpoint change response capability is improved, but device complexity and processing load increase
Solution Approach 1:
The video content is segmented into multiple tiles, allowing the server to prepare and cache individual tile segments independently. This segmentation enables the server to respond quickly to viewpoint changes by transmitting only the relevant tile segments, reducing the processing burden on the user device while maintaining fast response capability.
Solution Approach 2:
The server performs preliminary processing by pre-generating and caching multiple tile segments at different resolutions before the actual streaming occurs. When a viewpoint change request is received, the server can immediately transmit the pre-prepared tile segments without requiring complex real-time processing at the user device, thus improving response speed while keeping device complexity low.
2Manufacturing precision
If high-quality video is transmitted to all tiles, then video quality is improved, but network bandwidth consumption and streaming delay increase
Solution Approach 1:
Different resolution qualities are assigned to different tile segments based on their importance. The tile corresponding to the user's current viewpoint (ROI) is transmitted at high resolution, while other tiles are transmitted at lower resolutions. This local quality differentiation maintains high video quality for the visible content while reducing overall network bandwidth consumption and streaming delay.
Solution Approach 2:
The system dynamically changes the resolution parameter of video tiles based on the user's viewpoint and the importance of each tile region. By adjusting the resolution parameter adaptively - high resolution for ROI tiles and low resolution for non-ROI tiles - the system optimizes the balance between video quality and streaming delay.
3Adaptability or versatility
If multiple resolution tiles are cached and transmitted, then adaptability to viewpoint changes is improved, but server processing load increases
Solution Approach 1:
The server performs preliminary processing by pre-generating tile segments at multiple resolutions and caching them before streaming. This preliminary action allows the server to quickly adapt to viewpoint changes by selecting and transmitting the appropriate pre-generated tiles, reducing the need for energy-consuming real-time processing during actual streaming operations.
Data Source
AI summary
A region of interest (ROI)-based virtual reality (VR) content streaming server and a method are disclosed. The streaming server includes a communication unit that receives a request signal for a media presentation description (MPD) file regarding tiles of a tiled video, ROI) information, and a request signal for a segment file from an electronic device, and transmits the MPD file and the segment file corresponding to the request signal to the electronic device. The streaming server further includes a controller configured to, when the request signal for the MPD file is received, control the MPD file corresponding to the request signal to be transmitted to the electronic device.