Shoud I deinterlace dvd mpegs and quality question

[kb1985]

When I make divx AVI video I deinterlace it.
When I make a DVD video I do MPEG file which then I:
a) author
and
b) put a copy of the MPEG file on the other hdd as a backup.
Should I deinterlace the MPEG video too or there is no need because it will go on dvd and dvd program will interlace it again?

and the other question is

Is there a difference in quality between method 1 and method 2:

1. dv -> deinterlace -> mpeg -> avi
2. dv -> mpeg -> deinterlace -> avi

Thanx for your time!

[lordsmurf]

Never deinterlace.
http://www.digitalfaq.com/dvdguides/capture/understandsource.htm#interlace

[guns1inger]

If the source is interlaced (DV) and headed for DVD, leave it interlaced, as this will always look better. If you have a progressive TV and player, the hardware deinterlacer will do a much better job than any software deinterlacer.

If you are going from DV (in an avi container) to another for of compression - say Xvid (also in an avi container), then you lose quality twice using your methods. You should go straight from DV avi to Xvid avi, not encode as mpeg in between. You van chose to deinterlace along the way, if you wish, although I believe Xvid/Divx can also be interlaced.

So your paths should be

1. DV -> Mpeg -> DVD (no deinterlacing)
2. DV -> {optional deinterlacing} -> avi (Xvid/Divx etc)

[kb1985]

I was doing this:
dv -> deinterlace -> mpeg -> dvd
because I make MPEG copy of most stuff that I have on my home made DVD's because I often make xvid's of them. I thought that it was better than ripping the DVD's back to divx.