"Play speed" is the speed that you think the original was played (e.g., 18 fps for Super 8).
I recommend doing standard pulldown rather than any sort of motion estimation. Despite heroic efforts to improve motion estimation, it fails way too many times and will give you a mountain of weird-looking frames. I am in the process now of doing four separate restorations of the same material. Two of the 2x2 matrix variations involve using, or not using GamMac, because it fails to do the right thing quite often. The other two variations involve generating an alternate to motion estimation which I used, not to change frame rate, but to fix hundreds of screwed-up frames. In 90% of the cases, the fix was near-perfect but, as is always true with ME, when it fails, it fails spectacularly and calls attention to itself. So, I am doing another set of GamMac and no GamMac with an alternative to ME that doesn't look as good, but never fails.
You can adapt this code to create pulldown for whatever you are doing:
Code:
#18p -> 60i
avisource("video.avi")
assumefps(18)
changefps(59.94)
separatefields()
selectevery(4,0,3) #depends on wished field-order
#selectevery(4,1,2) #alternate field order
weave()