Resolution vs Aspect Ratio

[kmmoore]

I am sure this has been done to death already and I apologise in advance, but is there a FAQ or similar on the difference between encoding resolution and the output aspect ratio?

For instance, if I have a 320x240 MPEG1 clip which I re-encode to SVCD 480x480 how does the aspect ratio remain the same as 320/240 = 1.33:1 wheras 480/480 = 1:1

I use TMPGEnc to re-encode, so is it simply a matter of ensuring that the "keep aspect ratio" button is ticked, and if that is the case does that mean that the resolution is not related to the aspect ratio at all and I could theoretically use any horizontal/vertical resolution and still maintain the 4:3 aspect ratio.

Thanks,
Kevin

[Truman]

VCD don't use square pixels. That's why you have a resolution and aspect ratio setting.
For SVCD set 480x480 / 4:3 (or 16:9 if you have a 16:9 tv)