Deinterlace MPEG2 when converting to MPEG2?

[MadRat]

I've been putting off asking this question for a while now because it doesn't really fit as either an encoding or avisynth filtering question. My Hauppauge WinTV-PVR-150 records to DVD compatible MPEG-2 480i files. I'd like to take my wife's old beta camcorder tapes from high school and convert them to DVD but I'd also like to clean 'em up a little with avisynth filters. The part I can't figure out is the interlacing. Should I deinterlace the video, filter it, then reinterlace it? If I do won't that introduce artifacts? If I leave them interlaced and filter them will they still be interlaced when I'm done? Do I need some special software to get them ready to be put onto a DVD?

[zee944]

Don't deinterlace it. I assume your is true interlaced.Separate the fields, do your filtering, and weave them back to interlaced.

What do you mean on 'special'? You'll need an encoder, then a DVD author, then a DVD burner software. There are also all-in-one softwares for that.

[Video Dude]

Some filters can be used on interlaced material. Check the readme with each filter to see if it has an interlace parameter.

You can get excellent results if you Smart Bob (deinterlace), filter, and then reinterlace. I prefer this way since some filters will artifact motion if you separate fields to filter, and spatial misalignment of fields can occur if you resize.

Bob, Filter, Reinterlace Script:

Favorite Smart BOB
Filters
SeparateFields().SelectEvery(4,0,3).Weave()

where smart BOB could be:
Yadif(mode=1)
TDeint(mode=1)
LeakKernelBob(order=x, threshold=7)
etc...