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Post #634595

Author
Darth Mallwalker
Parent topic
Star Wars Laserdisc Preservations. See 1st Post for Updates.
Link to post in topic
https://originaltrilogy.com/post/id/634595/action/topic#634595
Date created
17-Apr-2013, 1:46 PM

Chewtobacca said:


I don't understand why this is the case, because Pulldown() is implemented using SelectEvery() internally.
Pulldown(a,b) is implemented internally as SelectEvery(5,a,b)

Perhaps I should have said:
SelectEvery(10, is better than SelectEvery(5, if the source is YV12.

Using Pulldown() every "3" frame is handled the same way:
you either keep the first two-out-of-three fields and discard the third,
or toss the first field and keep the last two-of-three.

Using SelectEvery(10, is more flexible. It allows you to
keep first two fields from 1st, 3rd, 5th, 7th, 9th... "3" frame and
keep last two fields from 2nd, 4th, 6th, 8th... "3" frame.

With 4:2:0 source you want to keep whichever two fields were encoded together.
Not always the first two or always last two, but alternating.