My laptop's display has native resolution of 1366x768, and I connect it to my TV which has 1920x1080i. My problem is that the only supported resolution for cloning is 640x480, which happens to be the only resolution that is supported by both the TV and the laptop's display.
But on Windows, I've noticed that cloning works without changing the laptop's display resolution, even when the TV doesn't support the same resolution. Instead of trying to set the TV on the same resolution as the laptop's primary display, they somehow scale each frame (using software scaling or more likely the GPU) to the TV's native resolution.
Is it possible to do that in Linux? I noticed that there is a --scale-from option in xrandr, and it looks like it does just that, but how do I use it? What would the command look like?