Skerdi, a player or receiver can't display anything, that's what the TV does. If the the TV is a fixed-pixel 1080 unit it has to use 1080 pixels vertically for a full picture to be shown. On a regular 480i DVD, if the player or receiver hasn't mathematically calculated extra pixels to be added to the 480, the TV itself does it to fill up its 1080 screen(note that although this allows showing a complete picture, the resolution isn't real 1080; it remains 480). Unless the upscaling that a player or receiver did would be visibly better than what the TV itself does(this varies)there's no advantage in having the player or receiver do it.
