Research On Key Technologies Of Adaptive Acquisition And Multicast Transmission Of QoE-driven Panoramic Video Streams

With the rise of interactive multimedia applications,panoramic video technology is also developing rapidly.Compared with traditional videos,panoramic videos have higher definition and different viewing methods,which can bring users a strong sense of immersion and a wider field of vision.With the increasing development of panoramic video,people have increasingly higher requirements for the viewing experience of panoramic video.However,the user experience of watching panoramic video is not only related to the quality of the video but also to various factors such as network bandwidth.Therefore,research on the quality of user experience of panoramic video is very important.Therefore,this paper proposes a user experience quality evaluation model composed of influencing factors of panoramic video Quality of Experience(QoE).In order to obtain this model,this paper conducts an experiment of subjective quality evaluation of panoramic video.In the experiment,user ratings,pauses,quality switching,latitude are collected and processed.Based on the data,the relationship between user scoring and pause,quality switching,and latitude was studied in depth,and then a QoE evaluation model including pause,quality switching,and latitude was established by fitting the relationship between socre and pause,quality switching,and latitude.Experimental results show that the model can accurately measure the quality of user experience when watching panoramic videos.Because the panoramic video has a larger resolution,the amount of data during transmission is also larger,and it needs to occupy more network bandwidth resources,which places great demands on the limited bandwidth resources.Therefore,this article transforms the expression of the established QoE evaluation model into an expression composed of the number of blocks,bandwidth,and quality level selection scheme,and then designs a set of panoramic video adaptive transmission schemes based on this expression.This solution maximizes the user's experience quality by selecting an appropriate quality level for each video block under the condition of limited wireless network bandwidth.In the real-time video streaming application,the capture device is used to record the scene and transmit the captured video to the server in real time.Multiple users can then access and watch the panoramic video with Head Mounted Display(HMD)by downloading the corresponding core video content from the server.Obviously,with limited bandwidth constraints,the uplink(panorama video camera to video server)and downlink rate(video server to end user)should be carefully selected to improve the viewing experience.Therefore,in order to further improve the overall performance of panoramic video uplink acquisition and downlink transmission,this paper proposes a QoE-driven panoramic video acquisition and transmission model for multi-user.This model considers the selection of the uplink camera video quality level and downlink Link video block quality level selection problem.To solve this problem,a rate adaptive algorithm combining(Karush-Kuhn-Tucker)KKT condition and branch and bound method is proposed.The algorithm first relaxes the problem,calculates the solution of the relaxation problem using the KKT condition,and then uses the branch and bound method to obtain the solution of the original problem.Simulation results show that the QoE value of the proposed algorithm is higher than that of other algorithms.