Strange artifacts appear post-IVTC (single scene)

[Comatose]

http://xs225.xs.to/xs225/08132/evil408.png

Look at the people in the center. They're taking about 1 or 2 steps every second, so there's not rapid movement.
Also, this scene for some reason makes the tritical IVTC filters REALLY slow down.
Infact, this scene looks good if you leave it interlaced since there are no interlacing artifacts.
I just want to learn what this is and why it's happening, since in the future I might encounter something that I won't be able to solve by just not IVTCing it.

The script I used is this:
mpeg2source("dvd.d2v")
Interp = nnedi(field=0)
deint = TDeint(mode=0,Order=-1,type=1,AP=55,edeint=interp,slow=2)
tfm(d2v="dvd.d2v",clip2=deint,order=1,Mode=5, slow=2).TDecimate(mode=1, denoise=true)

And I also cut this scene out with DGIndex. It's about 7 seconds long and 9MB big - http://www.mediafire.com/?x128dmnnmzt

[tritical]

That scene is setting off tfm's combed frame detection. If you use tfm(display=true,pp=1) you can see that it is being set off by the upper story window of the leftmost house (the block tfm draws is hard to see since it is behind the text). Possible solutions are to increase cthresh or increase MI so that the combed frame detection isn't triggered. Another option is to use a script that wont artifact as much on false positives, such as:

mpeg2source("dvd.d2v")
interp = nnedi(field=-2)
deint = tdeint(mode=2,edeint=interp)
tfm(d2v="dvd.d2v",clip2=deint,slow=2)
tdecimate(mode=1,denoise=true)

The downside is that in the case of true interlaced frames mode 2 of tdeint will output a blended frame (since no two frames in the bobbed stream will match), but personally I'd rather live with that.

[TheRyuu]

instead of tdeint as your deint try this:
yadifmod(edeint=nnedi())

Works better on anime then tdeint, IMHO.

[Comatose]

Thanks tritical, I'll try playing with it. I'll probably go with the first option since I can afford looking for scenes like this and using different settings just for them.

And wizboy, I'll give yadifmod a shot.

Thanks!