[MEncoder-users] inverse telecine with 60 fps progressive video

[Oded Shimon]

On Thu, Apr 07, 2005 at 10:55:27PM -0800, Scott W. Larson wrote:
> But doesn't interlacing pairs of frames together effectively
> eliminate every other frame anyway? Won't tinterlace combine two
> different frames at the end of the three-frame sequence making an
> ugly frame? I don't see how merging frames together into distorted
> frames will help the inverse telecine filter know what to do but
> I'll see if it helps.

No, it doesn't just drop every other frame, interlacing the frames 
means just that, it takes every 2 frames and turns them into 1 frame 
by interlacing them together to a double hieght frame. The source is 
like this:

1 1 2 2 3 3 3 4 4 5 5 5 6 6

after tinterlace, you get this:

1 2 3 3/4 4/5 5 6
(double hieght)

and after pullup, you get:

1 2 3 4 5
(still double hieght)

If you were to just drop every second frame, you'd still get a lot of
duplicates (1 every 5 frames). And because the phase changes, you
can't just drop the duplicates easily. When you interlace, the pullup
filter does the rest.

- ods15