PAL to NTSC nightmare
by Trevor Gilchrist
on
Mar 17, 2008 at 11:08:39 pm
Hi,
Just been handed a nightmare job (for me): a capture to QT from a DVCam tape.
The original master (as I understand it) was PAL 50i HD D5 tape, which was then dubbed to an NTSC 29.97 D5, from which was made the DVCam.
Still with me?
I'm given a capture from the DVCam as an NTSC 29.97 QT file, but it's playing slow. I assume because it was at some point taken from 25fps to 24fps (or 23.98?) to add the pulldown to get it to 29.97...
Aaaaagh!
Given that this QT is the only thing I have to work with, can anyone tell me how I can safely bring the footage back to it's 'correct' playing speed??? A speed change? Math was never my strong suit...
I've already removed 3:2 to get it back to 23.976 and it looks right (no fields).
Re: PAL to NTSC nightmare by Dave LaRonde on Mar 17, 2008 at 11:33:23 pm
[Trevor Gilchrist]"The original master (as I understand it) was PAL 50i HD D5 tape, which was then dubbed to an NTSC 29.97 D5, from which was made the DVCam....
I assume because it was at some point taken from 25fps to 24fps (or 23.98?) to add the pulldown to get it to 29.97..."
Well, which is it? If you want to have any success at all, you'd better get a history of what was actually done, or you could drive yourself nuts.
What if they ran the PAL D5 master through a Teranex box to get it to 29.97? And if they did slow 50i footage down to 23.976 and then added 3:2 pulldown, how is it that you see NO fields? They should still be there.
This isn't just a nightmare job for you, this would be a nightmare job for anybody, because you have no clue what they did. Your best bet is to research this tape's lineage, and that's a fact.
Re: PAL to NTSC nightmare by Trevor Gilchrist on Mar 17, 2008 at 11:48:37 pm
Del & Dave,
Thanks for the rapid replies, much appreciated.
The fields ARE still there, I just removed 3:2 pulldown in AE from the footage to get it to 23.976... after that, I was whole frames at 23.976.
My question was really about the speed increase, and del has given me an answer I can go try. I'm assuming they 'simply' slowed it from 50i to 23.976, then added 3:2, in which case I'm just surprised there's anything left to watch at all!?
trust me, I've been trying to determine the lineage of the tape, but it came from Romania, and all bets are off....
Re: PAL to NTSC nightmare by del chapple on Mar 18, 2008 at 3:24:23 pm
The fun part of hd is about to begin. 50i is essentially 25p if there are no differing field's. If you have a progressive tape in hd you can change the framerate 23.98/24/25/29.97/30 but it changes the run time, pitch corrupts the vitc etc. 25->23.98 you just have to do the math its about 4.1%. You would probably have more issues if they did a hd standards conversion through a teranex but the run time would be good. i'd be careful about the lingo, PAL is PAL, its a standard for SD the same as NTSC. HD is neither NTSC or PAL, HD is HD no matter what the framerate or where its being played. I hear this daily, i want a PAL D5, i can easily make a SD PAL D5, then i get oh no i want a 1080 50i and thats completely different..
Re: PAL to NTSC nightmare by Dave LaRonde on Mar 18, 2008 at 4:58:33 pm
[Trevor Gilchrist]"trust me, I've been trying to determine the lineage of the tape, but it came from Romania, and all bets are off...."
Sorry if I came off sounding bossy.
If you've got a file with pulldown removed -- plus audio, I'd bet -- you could render in a lossless codec at 23.976, reimport into AE, and conform the footage to 25 in the Interpret Footage window.
If they really did slow it down, that ought to get you in the ballpark.
Actually, I'd do a test on a portion of video with lots of motion in it. Field order? It's a crap shoot.
