Research On Adaptive Delivery Of 360-degree Video Based On Viewport

With the continuous development and improvement of Virtual Reality(VR)hardware and software facilities and VR platform,the VR industry ushered in a period of rapid development.VR creates a new immersive experience to the user.Panoramic video plays a key role in VR system.Panoramic video has characteristics of high frame rate,high resolution and 360-degree immersion etc.Those characteristics cause the data volume of panoramic video to be big and bandwidth intensive during transmission.Due to the limitation of the human eye vision,the user can only watch the part of the panoramic video with a head-mounted display(HMD)at one time.However traditional video transmission method causes bandwidth waste.In view of this,this thesis researches the adaptive delivery of panoramic video based on DASH(Dynamic Adaptive Streaming over HTTP)technology and viewport.The main contributions of the thesis are as follows:1.A panoramic video region prioritization scheme is proposed based on the characteristics of human vision and head movement.Different priority regions correspond to different quality levels of panoramic video content.2.A panoramic video adaptive transmission strategy is proposed based on bandwidth estimation,buffer status and prediction of viewport.Combined with the prediction of available bandwidth and viewport,the quality level combination of the panoramic video's priority regions can be determined and then the adaptive transmission can be implemented.3.A panoramic video adaptive transmission test system is designed and implemented based on the above-mentioned panoramic video adaptive transmission strategy.The system consists of the server side and the client side.The transmission of the system is wired.The server side is responsible for the preparation of the DASH content.The client side is responsible for estimating the bandwidth,monitoring the buffer area,predicting the viewport and downloading the video content.4.Test for functionality and performance of the system.To verify the effectiveness of the proposed adaptive transmission strategy for panoramic video,the proposed adaptive transmission method compares with traditional transmission.The result shows that the panoramic video adaptive transmission strategy can effectivelyreduce the bandwidth consumption on the basis of guaranteeing the user experience quality.