Progressive+Deinterlacing or Interlaced?

[dfourthhorseman]

I have been using divx 5.02 to encode avis from dvds to save as backups. I use DVDx to do this. If I don't do anything extra I get interlaced videos, so there seems to be two options, maybe three. One would be to have the setting to "All frames are progressive' and enable "Interpolate" De-interlacing within DVDx. The next would be setting it to "All frames are interlaced," because its suppose to enable a deinterlacing algorithim, which seems to work when I don't resize. The last would be to have both things turned on, which I remember why I set it to that once, maybe because Divx's deinterlace algorithm wasn't enough or maybe I was just paranoid.

So which of these three should I use to get better quality videos?

Thnx
Ruibing

[dfourthhorseman]

I made one short avi for each of these settings with DVDx 1.8a, and then analyzed them at a frame that should have interlace. If the timing is absolutely the same for all three, then it seems that having interlaced with no deinterlacing provides the best quality with no interlacing frames. Is this an accurate way to compare them? The two deinterlaced frames looks almost exactly alike, different from the one with none at 2x zooming. So should I set it to interlaced with no deinterlacing selected?

Thnx
Ruibing