How does DVDFab pick the resolution?

I have converted several DVD's to h.264 and it seems many have different resolutions. I usually leave the resolution to whatever DVDFab selects and just make sure the bits/pixel is always 2.5 which works for me. But I thought all DVD's (NTSC) are 720x480.

How does DVDFab pick the resolution? How does the conversion work from 720x480 to a 16:9 widescreen or even 1:1.85?

Shhhhh it's a secret

Just Secret? Not Top Secret?

Let me rephrase the question. What are the best resolutions for ripping the following DVD aspect ratios:

4:3
16:9
1:1.66
1:85

Thanks

DVDFab does'nt pick a DVD's rez when you rip the DVD. Whatever the rez of the original DVD is what your copy is going to be. Yes the coming attractions at the start of the movie maybe 4:3 then when the movie starts it will be in 16:9WS, But DVDFab does'nt pick any rez. whatever orig is that what copy is.
Forget about altering aspect ratios its a losing matter. If you have a 20 year old TV and think it will last another 20 years i'd say stock up on 4:3 aspect ratio. But IMO WS is now already. Most ppl own a up to date TV or HDTV for that matter.

4:3=1.33333
16:9=1.777778
1.6 through 2.2=1.77778 or higher, depends on your player's native screen aspect ratio and size and how the player software deals with images that are less/more than a perfect fit. If you are watching on a handheld, use one of the smaller sizes; if you plan to watch full screen on a PC or on a TV, use the largest available that has the correct aspect ratio and run the video bitrate slider up until you get at least 0.25 bits/pixel (more is better). You can add different aspect ratios (e.g. 2.25) to almost any of the profiles, but you should experiment with short files to see how your player deals with true widescreen content.

all NSTC DVDs are 480x720, irrespectice of aspect ratio.

i.e. a 4x3 aspect film is on the dvd as 480x720 , so is a 16x9 or wider film.

There's other informationin the DVD format ( I don't know exactly where) which tells PC software what aspect ratio to display at. That's what FAb picks up when it analyses a disc and shows a list of titles with their lengths & aspect ratios.

This is correct, all DVDs are 720x480, but the active video area can be different. The data is in the IFO files. We were discussing MPEG-4 conversions, which have options for output aspect ratio, which the DVDtoDVD modes do not.