I have some mpeg streams that look like they were deinterlaced. the video that was deinterlaced was telecined video. i would normally run an inverse telecine (ivtc) filter on the video and then encode it, however there is nothing left for the filter to find and the video will not ivtc correctly.

here is what the pattern looks like in virtualdub when i have telecined video

29.97
1. frame
2. frame
3. frame
4. field
5. field

however in this case it looks like this:

29.97fps
1. frame
2. frame
3. frame
4. mixed
5. mixed

what i want is the usual normal so called problem:

29.97fps
1. frame
2. frame
3. frame
4. frame
5. frame (duplicate of 4th frame)

normally my IVTC filter looks at the fifth image and removes it because it's a duplicate of the forth. well now that it's mixed, which i'm guessing is the deinterlaced blend thing done to it, i can not seem to convert my video from 29.97fps back to 23.976.

is there anykind of plugin or method in tmpegenc or virtualdub that i can use to convert the video back to regular so that i can run the ivtc filter as usual?

Or are there any suggestions to my perception of the problem?
Kreg