It is. I have a 2.1 hdmi cable. My cable box is hooked up to my xbox
The HDMI-IN port on the XBox is not HDMI 2.0 capable, it's only HDMI 1.4. Hence, no 4K. You'll need to hook up the XG1V4 to its own HDMI 2 port on the TV, or get a compatible splitter.