Interlaced lines in 24p footage.

S

Steve2012

Well-known member
The other day I had some problems with some 24p footage shot on DVX100B and edited in PP cs5. The clips that were cut together were interlacing. It was explained that the error was that I was editing on a 29.97 timeline as apposed to a 24p timeline. I corrected the issue with the advise given.

Today I shot 24p and edited on 24p timeline and most of the movement shots are showing interlaced lines? Don't get that at all. So I imported the same footage to a 29.97 timeline and the interlaced parts are still showing.


Any thoughts?

Thank you,

Steve
 
24pN is interlaced. It has 3:2 pulldown added to make it 29.97. If you shoot 24PA, there is no interlacing on the progressive frames and the extra frames are added to pad it to 29.97. Then the extra frames can be removed during ingest leaving prestine 24p. Gosh it's been so long since I had that camera!
 
bgundu said:
24pN is interlaced. It has 3:2 pulldown added to make it 29.97. If you shoot 24PA, there is no interlacing on the progressive frames and the extra frames are added to pad it to 29.97. Then the extra frames can be removed during ingest leaving prestine 24p. Gosh it's been so long since I had that camera!
Click to expand...


Thank you,

Steve
 
To be clear, "24pN" is a term which applies to the HVX200/HPX170 and refers to 720 Native mode, meaning the frame rates are record in their native rates -- 24p is 23.976; 30p is 29.97; 60p is 59.94.

On the DVX, there's 24p and 24pA. 24p is recorded with the standard 2:3 pulldown. 24pA is recorded with Advanced 2:3:3:2 pulldown. Advanced pulldown is easier to remove.

Edius, Vegas Pro (not Vegas Movie Studio), and Premiere Pro (not Premiere Elements) will all remove standard pulldown as well as Advanced pulldown. They do not do this at capture; they remove it when you put the footage on a 24p timeline. Avid will remove either pulldown while capturing. FCP can't remove standard pulldown automatically, but Cinema Tools can do so (Reverse Telecine) after you've captured. This is why, if you want to edit as 24p, you should always shoot 24pA.

Premiere Pro should be giving you native 24p with no interlacing. Are you sure you're in a 24p sequence? Does it show in all the footage?
 
Hi Dave, thank you for responding.

I am in a 24p sequence for sure. It only did it with one small clip, and when I tried to replicate it, everything worked fine. It was in the whole 3 minute clip with no cuts, and was showing up in the persons head as they moved it fast back and forth. Not sure what happened. Whether I recorded wrong or what. But when I film 24p and capture 24p now, all is fine. However, when I am capturing the footage, I can see interlacing in the footage of the preview monitor in PP but, as you say, when I drag it to the timeline, all is well. So I chalked it up to being that when capturing, as you mentioned, the pulldown is not removed, and maybe thats why I am still seeing what appears to be interlaced lines in the footage until dragged to timeline.

The other footage contained the interlacing right through the whole workflow. But like I said, I can't seem to replicate the issue. I must have done something wrong somewhere.

Steve
 
You're not actually capturing "as 24p"; you're taking the footage as-is from the tape, which is 24p in a 60i stream. If you play the captured files in anything else, yes, you'll see the interlacing. PP is doing an on-the-fly pulldown removal in the 24p sequence.

Also, if you put the same files into an NTSC (29.97) sequence, you will once again see the interlacing, because PP won't be removing the pulldown.
 
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