25p to 25i?

Hey!

I shot a video that I wasn't supposed to edit. Now it seems like I have to finish it after all. It was shot in 25p and the guy who was editing it couldn't work with AVCHD files on his ancient Hackintosh with the old FCP so he converted the files to 25i.
It looks ok, but I'm wondering is it worth starting a new with the original 25p files? What, if anything, is lost with 25i instead of 25p?

Thanks for any insight!

Start over again with the 25p files. They'll be cleaner, you won't have to deal with interlace artifacts. I so hate interlaced footage...

If you use the 25i files, you'll never get a progressive output to look as clean as it could be. Because interlace shows "fields" not "frames". Two fields make up one frame. One field is all the odd number scan lines, the other is made up of all the even numbered scan lines. So you're putting together a jigsaw puzzle, in a manner of speaking.

When a camera shoots interlace originally, it isn't shooting both fields at the same time, only one at a time, so they don't always match up perfectly, can look blurry, and image quality is lost when combining them into progressive frames.

A single progressive "frame" is the full image all at once.

Splitting a progressive frame into interlaced fields gives a much cleaner result, than combining fields to make a progressive frame.

Since you're using interlaced fields that started off as a progressive frame, it may not be as bad, but, still, interlaced playback won't show both fields at one time, just half, then half. So you end up with artifacts and less than your best image quality.

Start over with the original progressive footage.

I hate interlaced footage too.
It looks alright in FCPX though and the final version will only ever be on the Internet.
There's some politics involved which makes keeping this 25i edit as much as possible desirable. But I kinda want to start from scratch for optimum quality.
Hmmm.

I hate Interlaced too. And Progressive is much better on viewing experience and playback quality.

Hi Dmitri,

If you export 25p as 25i without De-interlacing on export, then you end up with Progressive segmented field (PsF) material.

In theory, you could edit the PsF footage in FCPX, inside a 25p project with no loss in quality at all.

You just have to make sure that the footage is correctly interpreted by FCPX before you start editing:

- Select all the clips in the Browser.
- Open the Inspector (which will probably describe the clips as being 25i)
- Select the "Settings" tab inside the Inspector, and set the "Field Dominance Override" to "Progressive".

Finally, you need to create all your projects in 25p, not 25i. Avoid working in interlaced projects if you are delivering for the web!

The final export should be 25p and retain all the scan lines that the original 25p footage had. I would do a test just to make sure that everything looks good, before starting to edit this way.

But the simplest and most recommend workflow is to use the original 25p footage. Don't you have that available? That would certainly eliminate all these headaches, and guarantees that no data has been lost due to recompression to another codec (by the way, which one is it?).

I hope you find it useful. Good luck with your project!

JPM Editor,

Thanks, that was super informative!

Yes, I have all the original footage. Although I'm missing some additional footage.

And it would be good to do it from scratch. However, this was a project were everyone involved were doing it for free/for fun. Then there were some clashes, so there's politics involved which would make keeping the first edit as much as it is as possible. Which of course complicates everything.

Thanks again!