Interlacing problems converting NTSC to PAL

Posted by MetalGuru 
Interlacing problems converting NTSC to PAL
January 26, 2012 04:25AM
I've recently been supplied with some NTSC (film sourced) footage on a DVD which I'm editing into a PAL project I'm working on.

The NTSC footage is 29.97, so I ripped it to ProRes (HQ) in MPEG Streamclip and performed a reverse telecine on it in Compressor which resulted in a 23.976 file. This file was then conformed to 25 fps in Cinema Tools, and then NTSC to PAL converted in Compressor.

When I edit the footage onto my PAL timeline I'm noticing that the first frame of many shots has bad interlacing, or jaggies. It seems to occur on just about the first frame of every shot change.

Should I have de-interlaced the NTSC footage using MPEG Streamclip first? I have also played around with FCP's field dominance settings (None, Upper/Odd etc) which doesn't seem to affect things. Any suggestions would be most welcome.
Re: Interlacing problems converting NTSC to PAL
January 30, 2012 07:34AM
Can anybody help please? smiling smiley
Re: Interlacing problems converting NTSC to PAL
January 30, 2012 05:44PM
My personal recommendation would be to use Nattress Standards convertor. There's so many steps in that process that could have gone awry its hard to troubleshoot, although tis bit "conformed to 25 fps in Cinema Tools, and then NTSC to PAL converted in Compressor" seems off. You essentially had 25fps NTSC, which you then converted to PAL? Not sure what you changed in the Compressor step, apart from frame size.

Re: Interlacing problems converting NTSC to PAL
January 31, 2012 10:31AM
It's hard to figure out without seeing the source file. Is the pulldown pattern consistent on the DVD? I can't imagine why 24p film would out as 29.97 on a DVD. Is the film edited in 29.97? If so, the pulldown won't be consistent. You can't reverse TC it easily if the pulldown pattern is not consistent.



www.strypesinpost.com
Re: Interlacing problems converting NTSC to PAL
January 31, 2012 01:30PM
I've seen lots of American released DVDs with a 29.97 frame rate. I guess it's mastered from an older source tape or is just a cheaply done telecine.

Re: Interlacing problems converting NTSC to PAL
January 31, 2012 01:48PM
Good point.

The most important part is to figure out if the pulldown is consistent. Then, you can move on to troubleshooting whether the software is removing the pulldown consistently.



www.strypesinpost.com
Re: Interlacing problems converting NTSC to PAL
January 31, 2012 02:01PM
I have no idea how to check pulldown consistency. Is this something I can easily find out?
Re: Interlacing problems converting NTSC to PAL
January 31, 2012 02:30PM
Check the source clip. Go through 5 frames, note the pattern of the jitter frames and the progressive frames. Then go through the next 5 frames to check that the pattern is the same. Then run through a few cut points. If the pulldown is consistent across cut points, that means that the pulldown is probably added universally after the edit. That or you may have a film is pieced together in different parts and the pulldown pattern will break across these points.

I'm not sure if there is a software solution that can scan a film for pulldown breaks.

There is also the free JES Deinterlacer, which removes pulldown.

[jeschot.home.xs4all.nl]

I'm not sure how these softwares work, but you probably won't want to transcode with the clip starting on black.



www.strypesinpost.com
Re: Interlacing problems converting NTSC to PAL
January 31, 2012 02:31PM
If the pulldown is not consistent across shots, then you have a problem, and you probably need to remove the pulldown shot by shot.



www.strypesinpost.com
Sorry, only registered users may post in this forum.

Click here to login

 


Google
  Web lafcpug.org

Web Hosting by HermosawaveHermosawave Internet


Recycle computers and electronics