All widescreen 16x9 anamorphic?

[Jeomite]

These questions is mainly about resizing 16x9 movies.
Here's the questions

[1] Are all widescreen 16x9 only and never 4:3?

[2] Are all widescreen 16x9 always anamorphic?

[3] When using the resize filter in VirtualDub for a 16x9 movie, do I always use 480x360, then letterbox to 480x480? Or is that *only* for anamorphic movies? If so, how can I tell when to resize to 480x360 and not (some movie discs I rent don't say it on the actual disc).

Thank you for any replies.

[VidGuy]

On #1, I know you can get 4:3 DVDs that have been letterboxed - it's quite common on the cheesier DVDs.
For #2 - I think that's mostly true, although I don't know for sure.
For #3, I believe the answer is yes, although the thing to do is download FitCD (from the Tools area) - it gives you all kinds of resizing options depending on how much you want to clip, how close you want to keep the aspect ratio, etc.....
I usually do
Clip(20,0,680,480) (clips 20 bits from left and right)
BicubicResize(480,382) (that's what FitCD says is correct)
AddBorders(0,49,0,49) (this is for CCE).

Then I mess around with the resizing and borders a little bit to force the black bars onto 16-pixel boundaries.