- Recently, I bought a TV card capture and did some screenshots running Rockman. By taking out the overscan area (black bars at left/right), the NES resolution was 600x475 (or near enough that). Is this the true stretching when outputting into a TV screen?
When I video capture the Super Mario Bros. title screen, the minimum rectangle containing everything on screen except the blue border is 589x448. The source NES image in this case is 256x224 pixels. So for my capture, the horizontal is being scaled by 2.3 and the vertical by 2.0, for an H/V ratio of 1.15.
A video capture might get slightly different widths, the same way the image on a TV will vary from one set to another.
There is no 224 height, except in incorrect documentation and Nesticle.
In this case, the source image I measured was indeed 224 NES pixels tall, not 240. SMB doesn't put anything in the top 16 lines of the screen (just the background color), so there's nothing to measure there. Not that the height really matters, unless you're using an annoying video capture that scales the image vertically instead of just de-interlacing it (which sort of doubles the height, in the NES case).