PeculiarBlend(clip clip, int cutoff)
This filter blends each frame with the following frame in a peculiar way. The portion of the frame below scanline number cutoff is unchanged. The portion above scanline number (cutoff-30) is replaced with the corresponding portion of the following frame. The 30 scan lines in between are blended incrementally to disguise the switchover.
You're probably wondering why anyone would use this filter. Well, it's like this. Most videos which were originally shot on film use the 3:2 pulldown technique which is described in the description of the Pulldown filter. But some use a much nastier system (involving a camera pointed at a movie screen) in which the crossover to the next frame occurs in the middle of a field—in other words, individual fields look like one movie frame on the top, and another on the bottom. This filter partially undoes this peculiar effect. It should be used before Pulldown. To determine cutoff, examine a frame which is blended in this way and set it to the number of the first scanline in which you notice a blend.