DivX -> DVD Aspect Ratio problem

[xzero]

I have a DivX file that is 512x352 pixels @ 25fps. It's fullscreen, so it has no letterboxing or borders around it. This leads me to believe that whomever encoded it, didn't resize it to account for PC square pixels, as 512x352 is ~ 1.46:1. I can also see that people are stretched out a bit more than should be, when watching on the PC. Maybe a 704x480 capture? But, that doesn't really explain the 25fps. Is it possible to capture an NTSC stream @ 25fps?

Anyways, what I'm trying to do is convert this over to an NTSC dvd. I have the 25 fps part worked out, as I'll just use DGPulldown to put it to 29fps for NTSC after I convert to MPEG2. However, I need the aspect ratio for this to be in 4:3 after conversion, as I at least know the original source is 4:3 and not letterboxed/widescreen.

What would be the best thing to do with AVIsynth? I know I could size 512x352 to 512x384 and that would give a 4:3, then encode to 720x480 dvd. Since this file seems like it may also be a 704x480 capture and hasn't been converted into a proper frame size for square pixels, is another possibility to resize to 704x480, then add 8 pixel borders to each side horizontally, to bring it up to 720x480?

Just wondering what the best thing to do here would be.
Thanks.

[yoda313]

Well I can't help you too much here as I don't use avisynth.

BUT 704x480 IS an acceptable dvd resolution. FYI.

[manono]

Hi-

If you're sure that it's supposed to be 1.33:1, or 512x384 (if a movie, you could look it up in IMDB), then what you propose is fine, but skip the in between step of resizing first to 512x384. It'll get straightened out when being resized directly to DVD resolution:

LanczosResize(720,480)

That's with ITU resizing. If you don't use the ITU resizing, then:

LanczosResize(704,480)
AddBorders(8,0,8,0)

By the way, you could adjust the playback Aspect Ratio of the AVI in a number of players and in ffdshow to check and make sure that 1.33:1 is the way it's supposed to be.

[junkmalle]

704/480 is 1.4666... So somebody probably just resized a 4:3 704x480 capture down to 512x352. Just resize back up to 704x480 and convert to 4:3 MPEG.

[xzero]

Yeah, thats what I was a thinking thinking it was; A 704x480 downsized to 512x352, instead of to a square pixel ratio (as it should have been ). It does look proper when resized to 704x480 and played in PowerDVD.

Thanks for the replies.