I'm building a hybrid app (hosted web app running inside a native app with a WebView). I noticed that the resolution of img and canvas elements is limited to 1080p, which I discovered by rendering test pattern images in an img element and also by drawing test patterns in a canvas element. This is despite
window.devicePixelRatio === 4 (which is true even when the display is 720p!).
I was worried that this was a WebView limitation, but I've also noticed that the entire Fire TV UI is a bit blurry, suggesting it's rendered as 1080p and upscaled (probably via hardware acceleration) to 2160p.
Is this really what's happening? Is true 4K resolution limited to 4K video playback only?