How does 480p Widescreen (16:9) work?

Factual Questions
1

Rather, I vaguely understand how it works, but I’m wondering whether it’s actually “better” than 480p full-screen (4:3).

To my understanding, both formats involve the same number of pixels, and even initial display ratio. However, when in wide-screen, the image appears squished until I manually set my 4:3 TV to wid-screen mode, thereby letter-boxing the top and bottom portions, giving the images a widescreen ratio.

What prompted this question was **Twilight Princess ** for Wii. I’ve done comparisons, and the widescreen mode certainly enables one to see slightly more along the horizontal access, and loses nothing along the vertical. This seems to suggest that, since both formats use the same resolution, that there’s a loss of detail in the widescreen image, otherwise how could they fit more into the same resolution?

Is my assumption correct, or am I totally off base?

2

I don’t believe that’s the case. Are you thinking the p in 480p means pixels? It actually stands for progressive scan resolution, and the 480 is the number of lines from top to bottom, which is about the same on both 4:3 and 16:9 ratios. (These display ratios aren’t the same, which took me a while to realize myself; 4:3 is equivalent to 16:12, not 16:9.)

The number of lines from left to right does in fact change. According to the 480p Wiki page, it’s 704 or 720 lines for 4:3 and 854 lines for 16:9. So 4:3 works out to about 720x480 for screen resolution and 16:9 is 854x480 in 480p display.

That’s kind of a jumble of numbers, but there is definitely more graphical information in widescreen mode than in standard 4:3.

ETA: Fool I am, the Wiki page actually describes the 4:3 ratio as 640x480 and the 16:9 ratio as 720x480. Completely missed that.

3

No, I realize it stands for “progressive.” I suppose in retrospect, I should have written it as 480i/480p.

Hmm, interesting. I’m confused then: When my TV isn’t set to “widescreen” mode, it still displays the full picture (so far as I can tell), just stretched to fill the whole screen. Is my still displaying the full horiztonal pixel width, despite not being set to “widescreen”?

4

I’m not sure what you’re asking, really. You have an image set to display in widescreen, such as HDTV or the Wii configured for 16:9 (I just finished playing Twilight Princess myself in widescreen, such an enjoyable experience), but the TV itself isn’t set to widescreen. In that case, the widescreen view would be scrunched into 4:3, yeah? I don’t know what happens to the extra lines there, though.

Alternately, you have a 4:3 image and your TV is set to widescreen, which will stretch the image out. Again, I couldn’t really say what the TV does to ‘fill in’ the extra lines.

I’m afraid my technical level isn’t high enough to explain what the TV’s doing in either case. I just know enough to be able to say that images configured for 16:9 will have more detail than 4:3 images (or the same detail per square inch, just more square inches), regardless of how the TV is displaying them. I’ll bow out from here for more knowledgeable posters to come in.

5

You answered my initial questions and I know my followup made not have made the most sense, but you got the essence of what I was asking. Thanks!

6

It sounds to me like your TV doesn’t have enough pixels to display a full-sized widescreen image, so yes, on your TV, widescreen mode would imply some loss of detail. But on a true widescreen TV, the widescreen image would fill the screen, and a 4:3 image would be “letterboxed” with black bands on the left and right.

7

The OP may be thinking of how “anamorphic” widescreen DVDs work, which is as he describes. The images on a 4:3 DVD and and anamorphic 16:9 DVD contain the same number of pixels in both directions, it’s just that the 16:9 image is then scaled either by stretching horizontally (on a 16:9 TV) or by omitting scanlines (on a 4:3 TV).

Whether the Wii uses this technique or really does produce a higher resolution picture in widescreen mode, I don’t know. A quick Google suggests that maybe it does use anamorphic.

8

Hmm, interesting. Thank for the reply!

So if the Wii uses that same method, does that mean it might be sacrificing some picture quality in the process?

9

If it is producing anamorphic 16:9, then it is more a case of it not providing any extra detail than in 4:3 mode. If you then view that 16:9 image squashed to fit into a 4:3 frame while retaining the aspect ratio, you are losing scanlines.

10

I’m going to have to check this out, because I’m pretty sure the TV’s back at my parents don’t fill the screen with either. 4:3 is letterboxed vertically as described, but any “widescreen” mode has to be scaled to show up properly. Maybe I don’t have any proper widescreen DVDs/Videos to try on it.