Need advice on remove 3:2 pulldown, effect on timing, ect?

[Darby Edelen]

I don’t deal with 3:2 pulldowns all that often, so you might want to wait for someone with more experience to respond, but I’m pretty sure that you add the pulldown back in on render.

Darby Edelen
DVD Menu Artist
Left Coast Digital
Aptos, CA

[Darby Edelen]

[Darby Edelen (wuzelwazel)] “I don’t deal with 3:2 pulldowns all that often, so you might want to wait for someone with more experience to respond, but I’m pretty sure that you add the pulldown back in on render.”

I think I should clarify some.

My understanding of the workflow is that you should use a 23.976 fps composition for your 23.976 fps footage (pulldown removed). When you render, click on the Render Settings and make sure to render with fields in the correct order and add the pulldown back in.

Darby Edelen
DVD Menu Artist
Left Coast Digital
Aptos, CA

[Ronaldo Montalvo]

just wondering, why even remove and add back the 3;2 pulldown. maybe i’m missing something but i don’t think it’s really necessary is it? the transfer is done at 29.97, final cut is at 29.97. i’d say ignore the pulldown, do your afx stuff in a 29.97 comp and export back out at 29.97.

[Darby Edelen]

[ronaldo] “just wondering, why even remove and add back the 3;2 pulldown.”

You know, I’m not really sure if it’s necessary. But because the pulldown adds an extra frame every four frames I thought that it might be more technically correct to remove the extra split frames for effects/compositing and then add the pulldown back in so that they are properly interlaced in the extra split frames generated.

From Adobe’s LiveDocs:

“When importing interlaced video that was originally transferred from film, you can remove the 3:2 pulldown that was applied during the transfer from film to video as you separate fields so that effects you apply in After Effects don

[Steve Roberts]

If you’re doing anything in AE beyond color correction, I also recommend removing the pulldown (when interpreting the footage), doing the AE work in a 23.976 comp, then rendering at 29.97 with pulldown in the Render Settings.

[Kevin Camp]

your workflow would be to set ae to interpret footage leaving the frame rate alone (unless you know it is incorrect), then set to separate fields appropriately (upper/lower) and then to remove the pulldown. guess should work, if it doesn’t check the footage for edits, if there are edits you’ll have more work. if guess doesn’t work check the first five frames of you clip and note the cadence of progressive frames (‘w’) and interlaced frames (‘s’) and manually set the cadence from the remove pulldown dropdown menu.

now drag the footage in to the make comp button (this will create a comp that is the same size and frame rate (should be 23.976 or 23.98 now). you won’t need to worry about frame rate until you render.

when you render you will want to put the pulldown back in. click the open the render settings and set to add fields (specify the same dominace that the orig footage had) and select the pulldown cadence (it shouldn’t matter which, but if you wanted you could add the same cadence the footage originally had). you might also look at the frame rate, it should have changed to 29.97 after adding the pulldown. now you’ll render your 24p back to 30i.

Kevin Camp
Designer – KCPQ, KMYQ & KRCW

[Ronaldo Montalvo]

the consensus and the docs seems to be remove and add-back pulldown. the thing i’ve noticed with removing the pull down and adding it back, aside from the difficulties you get if there is a change in the pulldown order of the clip-which frequently happens with stock footage, is that if i do something like a text crawl over that 23.976 footage when you rerender it out at 29.97 with re-introduced pulldown the footage looks ok (as OK as it did with the original pulldown) but the crawl looks funky from the start and stop nature of adding back 6 dup frames every second to the afx motion.

[Kevin Camp]

this is also why when you start a 24p project you should stay 24p until you’re done… don’t shoot 24p to tape, then capture that 30i -24p-with-a-pulldown footage and edit it with out first removing the pulldown. and just remove it at capture. then when you add effects you won’t need to remove the pulldown if it was removed at capture and it edited as 24p. you’ll render out effected footage as 24p that will be imported and edited as 24p. a 24p project should never get converted to 30i until it’s finished.

and if you needed to add true 30i to a 24p project, well you shouldn’t have even started trying to do 24p in the first place.

24p isn’t really the problem, it’s when you try to work with it as 30i that it becomes a problem. just work with it as 24p, ignor broadcast standard 29.97 until you need to go to tape (or broadcast playout device).

Kevin Camp
Designer – KCPQ, KMYQ & KRCW

[Tyler Paul]

I’m in the process of doing the effects and final color correction for a friends film. He made the error of capturing at 30i and then editing before I ever got the footage. I’m sending him an e-mail trying to explain this whole pulldown thing but since it’s new to me as well I wanted to make sure I got everything right. And to make sure it he can understand it.

* * * * * * * * * * *

You shot at a framerate of 24p.
P = Progressive = it’s not intelaced.

When you captured the footage to your harddrive you converted it to the framerate of 30i and it automatically applied an intelaced pulldown. 30i with a pulldown is really only partially interlaced.

A pulldown fills in additional non-existant frames with interlaced duplicates of the existing frames.

There is a five letter code system to represent the “organization” of the pulldown.

W=Progressive
S=interlaced

Possible combinations are WWWSS, WWSSW, SWWWS, ETC

WWWSS = Full Frame, Full Frame, Full Frame, Interlaced Frame, Interlaced Frame
Then repeats that for the next five frames

————————–

First thing to remember. If you shoot in 24p you should keep it at 24p until your finished. Look into the settings of whatever you use to capture and see if you can’t adjust that.

Secondly, if it has already been converted to 30i with pulldown then you should remove the pulldown before editing. This will replace the interlaced frames with duplicates frames. You do this because if you edit two pieces of pulldowned footage next to each other it will most likely screw with the order of the pulldowns. That’ll make it impossible to deinterlace correctly. This is a problem that I came across in editing Mercedes Ray. Also, this is PART of what caused the jitters. The pulldown would be correct for some of the shots but get screwed up when it cuts to the next shot.

When I tried rendering down to native DV settings without deinterlacing your footage I still saw a bit of jitter. That was because native DV is 30i, fully interlaced. It was rendering pulldowned footage (partially interlaced) into a fully interlaced format and those partially interlaced frames would then be re-interlaced to spread over about four frames I reckon. I just started rendering to DV 30p which should preserve the pulldown…..

* * * * * * * *

So…
Do I understand all this correctly? I couldn’t get rid of the pulldown because it was edited with the pulldown. Should rendering down to 30p actually preserve pulldown since (I assume) AE treats a comp as progressive? Or was the jittering I saw when rendering to down to 30i just in my head?

[Kevin Camp]

ok, here we go…

You shot at a framerate of 24p.
P = Progressive = it’s not intelaced.

if you shot to a hard disk or p2 card or some other storage device, then you should have 24p (progressive)… if you shot to tape then you actually have a 30i version of 24p (with a pulldown added to get to 29.97). generally, you can only record to tape at 29.97.

When you captured the footage to your harddrive you converted it to the framerate of 30i and it automatically applied an intelaced pulldown.

the pulldown was added when the shot was recorded to tape, when you capture from tape you should be able to remove the pulldown, recording only the 24p to your disk. there are big advantages to removing the pulldown at capture. you use less disk space (24 fps vs 30 fps). most codecs that you capture to will look better when they compress progressive frames than when the compress interlaced frames. you can place edits any where you want, with out concern for messing up the pulldown cadence thoughout you project. you won’t be removing the pulldown to effect clips and then having to put the pulldown back in to edit. you want to burn a progressive dvd, well you can take your 24p project staight to the dvd software. when you need to go back to tape, render your project with a pulldown, and since the cadence will be consitent throughout the project, you can recapture and remove the pulldown and you’ll get your 24p file back.

30i with a pulldown is really only partially interlaced.

correct. its a combination of the progressive frames with interlaced frames filing the gaps made by increasing the frame rate.

If you shoot in 24p you should keep it at 24p until your finished

yes.

Secondly, if it has already been converted to 30i with pulldown then you should remove the pulldown before editing. This will replace the interlaced frames with duplicates frames

yes, you should remove the pulldown before editting or effecting. the duplicate frames should be removed by working in a 24 fps (actually 23.98 or 23.976) project, timeline or comp.

if you edit two pieces of pulldowned footage next to each other it will most likely screw with the order of the pulldowns. That’ll make it impossible to deinterlace correctly

yes (although you can remove the pulldown, but you will essentially have to split the footage up at each edit to do so… basically re-edit).

as you found out in the end, you had to interpret the footage as not having fields (treat as progressive). you can do some effects without deinterlacing (like color correcting or overlaying still elements). but even if you wanted to animate a simple element, you would start to run into issues, and if you had to key or manipulate the scale or position of the video you’d really start to run into problems.

Kevin Camp
Designer – KCPQ, KMYQ & KRCW