movie texture 360 low fps

Hi im currently trying to create a 360 movie project using unity

everything else is perfectly fine just 1 problem my movie texture fps is so low when i run the program the movie is 2048x1024, i convert from mp4 to ogg with 4k video bit rate (i need the video to be HD) anyone knows why the fps is dropped? i thinks it's about 18 fps

the quality of the video is also bad, is there any way to maintain the HD on ogg file?

thanks