Aspect ratio confusion

[Chaobunny12]

So a friend of mine recently told me that my aspect ratios for my AMVs are "wrong," and I'm not sure how to fix the problem. I've been preparing my footage with DVD Decrypter, DGIndex, Avisynth, and Virtualdub for as long as I can remember, but the default settings seem to always set the PAR of the output I get to 1.00, so that's what I've been editing with. It's always seemed to work fine, but I guess this is a big no-no, but now I can't really figure out where I'm suppose to change the settings or in which program for my video footage to come out with the right PAR. So I'm a bit confused in general, but my question is whether I need to change settings in DGIndex, do something in a script, or change a setting in Vdub to make the PAR of my clips correct. DGIndex acknowledges my DVD footage as 16:9, but the final output from Vdub always seems to be a PAR of 1.00.

So if I could get some clarification, that would be great.

[Zarxrax]

AVI files only technically support a PAR 1.0.
But aside from that, getting the correct aspect ratio is simply a matter of resizing, nothing more.
If your footage is 16:9, then its resolution should be something like 848x480.

[Chaobunny12]

Okay, thanks!

[Qyot27]

Zarx beat me to it, but to expound further on the concept involved:

What DGIndex reports is that the VOB contains 16:9 flags - it does not mean the file is already at a ratio of 16:9 (and neither is it at a PAR of 1.00, but incorrect settings in the editor can cause that to happen). To properly edit at a PAR of 1.00 and aspect ratio of 16:9, you have to resize 720x480 (which is technically a 3:2 ratio) to 848x480; likewise, to deal with 4:3 at a PAR of 1.00, you have to resize to 640x480. VirtualDub does not perform AR correction, you have to do it yourself.

If you don't want to resize the footage yourself prior to editing, then you have to make sure the editing program is set to the correct PAR so it knows the footage is not using Square Pixels (which is what PAR 1.00 means). Otherwise it will deal with PAR incorrectly, but as long as there weren't any effects dependent on the AR, then correcting it is more or less just a matter of resizing to a proper 16:9 or 4:3 ratio using Square Pixels, or setting the right AR flag in the container you're using for the distro version (and aside from AVI, the common containers all support aspect ratio flagging).

[Mister Hatt]

AVI files in fact support whatever the hell PAR you want to throw at them as the AVI container doesn't really pay attention to anything to do with aspect. Decoders on the other hand are a different matter. Otherwise, what Zarx and Qyot said.