I'm an idiot, please explain 24p/24pA and FCP editing to me

[mr_goodbomb]

I prefer the look of 24p. I use Final Cut Pro 5.0.4 to edit.

I just can't seem to wrap my head around 24p and the issues it brings with editing, or why 24pA is better for editing with Final Cut. I shot an entire feature in 24p, and then realized, after editing... it's in a 30fps timeline. That really got me worrying about the whole issue.

Since, I've been doing freelance videos, and in an effort to create the highest quality image to turn in for clients, I want to be sure I get it right. The manual, the various sites people have directed me to... I just can't seem to wrap my head around it. CreativeCOW is far too patronizing for my tastes, I can't tolerate their posters. If you don't understand something, they explain down their nose in MORE technical terms, and if you don't understand that, don't expect assistance.

I'm just trying to understand it, and how I should be shooting in the future. I'd also like to know if there's any salvaging that feature film. Maybe export to tape, and re-import? to a different timeline?

I appreciate all the advice I can get. Thanks.

 

[Alex H.]

First, which camera are you using? Sounds like the DVX, so that's what I'll use here. But if your camera is different, this may not be the same:

Many cameras, such as the DVX, record 24p material to 29.97 no matter which flavor of 24p is used. This is done using the addition of a pull-down, which adds extra frames to fill out the 29.97 stream. These frames are interlaced, and either version of 24p can be edited on a 29.97 time line.

The difference between 24p and 24pA is in the cadence, where 24p has a 2:3 (2:3:2:3) cadence and 24pA had a 2:3:3:2 cadence. Roughly translated, since the 29.97 video is an interlaced format, the cadence tells you how many sequential fields of video are created from each original, progressive frame. Yeah, that's some technical jargon, but there's a really good, easy-to-understand breakdown of what this means HERE.

So what does this mean for FCP? Well, FCP can remove advanced 2:3:3:2 pull-down at capture and edit 24p (23.976) material. That means 24pA source footage. So moving forward, shoot in the advanced mode. But not all hope is lost for what you've shot in the regular 24p.

For everything you already have in regular 24p, you can use CinemaTools (should have been bundled with FCS) to manually remove the 2:3 pull-down. It may be a little time consuming, but you'll be able to take the resulting files into FCP and edit a new, 24p version.

By the way, you're not an idiot. This can be a bit confusing for folks who haven't been working with it for a long time.

 

[mr_goodbomb]

I really appreciate the post. So, I should shoot 24pA for these quick little video jobs, and edit in a 23.976 timeline?

For the material I shot in 24p that was captured to a 30fps timeline, is there anything I can do? Export to tape? How would I go about using CinemaTools to remove 2:3? A shot at a time, or? Would my audio (which has no been exported to OMF, and an audio supervisor has mixed and mastered it) match up?

 

[Alex H.]

So, I should shoot 24pA for these quick little video jobs, and edit in a 23.976 timeline?

Yes. If you want to edit in and output to 24p, shoot 24pA.

For the material I shot in 24p that was captured to a 30fps timeline, is there anything I can do? Export to tape? How would I go about using CinemaTools to remove 2:3? A shot at a time, or? Would my audio (which has no been exported to OMF, and an audio supervisor has mixed and mastered it) match up?

If you've already edited, there's going to be a challenge. Since it's already cut together, there's no way to remove the pull-down from the exported video since the cadence isn't guaranteed to be the same from cut to cut. Each clip needs to be processed individually, which is going to mess with the existing edit. All your in-points and out-points are going to be skewed since you're changing your time base.

Audio is not frame-rate-dependent, so it doesn't really care if you're in 29.97 or 23.976. As long as it is 16-bit/48kHz, it is happy. You could, theoretically, re-edit the video to match the mixed audio, but that's going to be an enormous PITA. The other option: re-edit and send out a new OMF. Yes, that will require a new mix, but (speaking in terms of ProTools) mix automation can be copied from the previous version to a new session with the new audio, expediting the process. it will certainly require some tweaking, but it can be done.