In theory, this could do it and you will just watch whatever the online video was, in your Apple Tv set 4K. What's new is that the iPhone is currently ready to stream, and The brand new Apple Tv set 4K is currently in a position to obtain, 4K HDR https://stream-tv-in-4k-now35780.tinyblogging.com/rumored-buzz-on-youtube-tv-stream-4k-77334358