Wireless Transmission Optimization For VR Video Coding

With the development of wireless video communication,VR video especially VR broadcast has a rapid growth.However,the VR video service shows a lot of new features compared to the traditional video communication.Through a lot of research,we find that the VR video is developing towards high resolution and high frame rate.That means higher compression efficiency for our video communication system is in need.Traditional digital video communication has been unable to meet the requirements of VR video.Therefore,under this trend,we have to put forward some new wireless video coding strategies to meet the developing needs of the VR video service.Recently,a new wireless video coding algorithm called "SoftCast" has been proposed.It is a video coding scheme based on cross layer optimization.SoftCast has smooth transmission performance in the field of wireless video broadcasting,so it can guarantee the fairness among different users.SoftCast has better value and research significance,and it is more suitable for application in VR video coding.However,when the channel bandwidth is low,or the image is large and the coding needs to be compressed,the SoftCast does not have good performance.VR video is characterized by high resolution and high frame rate,which requires compression more than other video transmission.Therefore,this thesis based on SoftCast proposes a new unequal block coding scheme named UBCAST and a power allocation scheme for unequal block scheme.It can guarantee the fairness of the user and in the same time VR video can achieve better transmission performance even if it is compressed in a large compression ratio.Based on a series of theoretical analysis,we can conclude that when the proportion of low frequency area which is devided by 16*16 block is higher the image recovery quality will be better.At the same time,for the VR panoramic video,we can increase the proportion of 4*4 block coding area to get a higher compression ratio,meanwhile it has good recovery performance.Based on a series of theoretical analyses,this thesis also proves the rationality and effectiveness of the UBCAST system through a large number of experiments.In the case of high compression efficiency,UBCAST can get a better performance than SoftCast by 10dB.