Currently there is a very popular niche of LED devices to add a TV backlight based on what is currently displayed. But all of them are based either on camera or HDMI proxy device box that is only capable to captures streams from external sources(and re-stream them to the TV via HDMI).
My question is whether it is possible to get a live stream(or at least low-res mirror) of what is currently displayed on TV, ideally to reverse the HDMI port to act as an output video stream, or a background app that is able to provide the stream of current view from TV?