Deinterlace Encoded AVis

[kakomu]

I wanted to know if there is a method to IVTC an already encoded avi 29.97 fps file down to 23.976 fps. I was hoping to accomplish this task short of encoding to mpeg-2, using avisynth or DVD2AVi to IVTC and then re-encoding. As far as I can tell, most IVTC methods seem to only work with mpeg-2 streams.

[hakko504]

The answer to that is maybe. All techniques described here are just as valid for AVI input as they are for MPEG(-2). But they all require a clean input, there must not be any (or very little) cross information between lines and if you are using DivX3 there will be crossinfo as it stores data in progressive YV12.
Check your input carefully: Do you see blended fields? If yes, then you cannot IVTC. Do you see interlaced lines (jagged edges) in 2 or 3 frames out of a sequence of 5 repeatedly? If yes, then you probably can IVTC it. You may have to do some strange stuff in AviSynth2.07, like:
LoadPlugin("decomb.dll") #Add path, is included with GKnot
AviSource("NTSC.avi") #Add path
AssumeFieldbased() #This will convert video from progressive to fieldbased
Telecide(guide=1) #You probably need to change some other parameters also
Decimate() #This one shouldn't be any problemsAnd you should use AviSynth2.07 as Assumefieldbased is working much better in this case when you have YUY2 data.