Originally posted by: Citizen
I've updated it further now with true calculation source numbers because PAL 720x576 & NTSC 720x480 aren't true 4:3 resolutions.

I think I have a little problem with that. I know you've been looking at a super-technical page (from Finland) and have made adjustments accordingly, but I think I'd like to ask you to reconsider. Here is my rationale:

For a fixed-pixel display (such as a projector, which I don't own yet but will someday), the aspect ratio is fixed, and there is effectively no overscan. So the source material should ideally be full width (i.e. 720, say) with no black at all. Given that, then the height is the only variable that can affect the AR, and it does so in a non-CCIR way.

Once things are digital, then we have the flexibility to make sure round things stay round -- and I don't see a lot of hand-wringing about CCIR specs built in there. For example, many projectors are 854 x 480, which is 16:9 square pixel. It's clear that the source is meant to be DVD, with no overscan.

Now, for a real TV, getting the AR "right" is sorta pointless, because a CRT can be (and is) adjusted to mess with the AR, and the edges hidden by a bezel. So the minute differences made by CCIR-compliant calculations sorta make no difference at all, when some doofus at the factory wasn't all that careful, and your TV is actually displaying 4.2:3 already!

Given the additional fact that an increasing number of masters never actually exist as NTSC or PAL until they're converted to DVD (since they come via an HD master), and the people doing the conversion are probably computer nerds and not broadcast engineers, isn't it likely that a lot of the CCIR rules are sort of irrelevant, and therefore things are being done strictly on a straight math calculation (i.e. 720 x 480 is 3:2; figure out the PAR for NTSC at 4:3; convert on that basis)?

That's my take. Don't know if I'm right. Hope it contributes to the project, by at least making you think and/or explain why I'm out to lunch!