My TV (Vizio Smartcast) has an diagnostics panel that tells you your input resolution.
So -- assuming the input device isn't compressing and then upscaling, which a Chromecast wouldn't -- it's easy to see the resolution, for Chromecast, XBox, whatever.
So -- assuming the input device isn't compressing and then upscaling, which a Chromecast wouldn't -- it's easy to see the resolution, for Chromecast, XBox, whatever.