Originally Posted by BwanaP
So that tear has to be from the conversion then? I mean the camcorder would not have recorded like that.
Yes, the way the frame rate conversion was handled was to repeat parts of some frames. Say for example you have 2 frames and you want to make three. You keep all of the first frame, and all of the last frame, but in the middle you have a frame with the top half from the first source frame and the bottom half the second source frame. With interlaced video, where each frame contains two separate images taken at two separate points in time (and intended to be seen sequentially) you now have a frame that consists for four points in time -- but it's displayed as only two separate pictures. So at playback you get parts of the motions jumping back and forth.

I've never seen a video frame rate conversion done this way. Although there is some precedent. The tearing you sometimes see in video games is due to a similar process.