Quote:
Originally Posted by madshi 
Is there a specification which defines that? Or an EBU recommendation or something? Or is that just your personal experience?
In my experience at least 99% of all PAL content has the correct fields to weave in the same frame. But to every rule there is an exception. As I said, I have a sample of a PAL DVD where the correct fields to weave together are *not* in the same frame, similar to the original Cheese Slices. Also, an IVTC algorithm which claims to support "any cadence" (e.g. for Anime sources) has to be very flexible, and should have no problem finding the correct fields to weave, even if they're spread over two frames, like with the original Cheese Slices. With hard-telecined 3:2 content it happens all the time that the correct fields to weave together are not in the same frame. So supporting this for PAL, too, is an automatic side effect of an "any cadence" IVTC algorithm.

Is there a specification which defines that? Or an EBU recommendation or something? Or is that just your personal experience?
In my experience at least 99% of all PAL content has the correct fields to weave in the same frame. But to every rule there is an exception. As I said, I have a sample of a PAL DVD where the correct fields to weave together are *not* in the same frame, similar to the original Cheese Slices. Also, an IVTC algorithm which claims to support "any cadence" (e.g. for Anime sources) has to be very flexible, and should have no problem finding the correct fields to weave, even if they're spread over two frames, like with the original Cheese Slices. With hard-telecined 3:2 content it happens all the time that the correct fields to weave together are not in the same frame. So supporting this for PAL, too, is an automatic side effect of an "any cadence" IVTC algorithm.
I have no problem with that. My personal experience is the same, 99%. It's just that using the term 2:2 pulldown to describe this sequence is referring to the pathological 1%, and that's why it's confusing. I can definitely see where an IVTC algorithm could find repeat fields somewhere in this sequence (although the fields are not 100% repeats in my example at around frame 140 above because of the horizontal lines).
All I'm saying is that the repeat fields are just an artifact of a mistake in how the pattern was fabricated as a collection of interlaced frames. By having no motion from bottom field to the top field of the next frame, the pattern is depicting motion that is not natural. That is, it can't happen in video of the real world.
I have to agree with madshi that the pattern is flawed.
However, I'd like to see us all work together on this rather than pointing fingers.
Ron
















do you hate Cheese Slices hmmmm..?

