[Mark Floyd]

You can go from 23.976p to 29.97p with no duplicate frames, but at the cost of resolution. You can add pulldown which will convert from 23.976p to 29.97i. You can then add a deinterlace filter (frame blend) to get to 29.97p. I personally think frame duplication looks better, but using the correct deinterlacing filters will give you the smoother motion I believe you are looking for.