30P and DVD playback

Laurence wrote on 10/19/2005, 10:54 PM
I'm looking for the best SD format to render from my HDV footage. 24p looks good but 30p might be a little better. My question is, do progressive mode DVD players do true 30p progressive, or is 60i with 30p progressive footage for all practical purposes progressive anyway? I'm not really that interested in the "cadence" of 24p, but I do like the sharpness of progressive footage. I am interested in a progressive look that will look like it should on most TV/DVD player combinations.

The format will be 16:9, so I'm also interested in how it will look letterboxed on a 4:3 TV. One of the things I hate about 60i widescreen is how it looks letterboxed on a 4:3 TV after the mangling of dropping lines and hardware deinterlacing. I find that progressive 16:9 footage looks better letterboxed.

Comments

farss wrote on 10/19/2005, 11:21 PM
As far as I know the DVD standard doesn't support true 30p so yes you create a "30PSF" DVD which as you say is for all intents and purposes is a 30p DVD.
I don't understand though why you're having an issue with 16:9 60i unless you're referring to what's happening on progressive devices such as plasma and LCD.
Bob.
Serena wrote on 10/20/2005, 1:13 AM
Can you describe more fully what you dislike about the image? Presumably it's not the letterboxing but rather something about 60i.
Laurence wrote on 10/20/2005, 12:56 PM
Well letterboxed 24p looks pretty sharp. Not quite as clear as it does on a 16:9 screen but not bad either. When 16:9 60i is played back on a 4:3 set, it just looks kind of blurry to me and the motion doesn't look that smooth either.

I checked around a while back and the reason seems to be that as the 16:9 footage is letterboxed, every fourth line is dropped. On 24p footage this is no big deal (even with the 3:2 pulldown) as dropping every fourth line of a progressive image doesn't screw up the interlacing. With 60i footage however, dropping every fourth line messes up the interlace pattern, and rather than have half the interlace lines being shown in the wrong field, the whole screen is hardware deinterlaced ( I believe with a blend fields deinterlace). On a small set this isn't so bothersome, but on a larger 4:3 TV it is quite noticable. Instead of looking at letterboxed 60i, your actually looking at hardware deinterlaced 30p that is reinterlaced by the TV. I just don't like the look of it at all. That is one reason why I have been doing both 4:3 and 16:9 versions of all my projects thus far.

It seems to me that 16:9 30p stuff could go through the process of having every fourth line dropped and a hardware blend fields deinterlace and come through this relatively unscathed. I've never seen this discussed though, so I'm just not sure.