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  #11  
Old 09-15-2005, 04:31 PM
José Luis Díaz José Luis Díaz is offline
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Default Re: PAL to NTSC speed change?

Richard,

> "why do you need to multiply by 10K? Why not just enter 23967 and 25000? The ratio is the same either way, isn't it?"

Mmmm,
Yes, you are right.
ProTools must arrive at the same ratio. Doesn't matter the amount of zeros.
My initial presumption was that if I give the maximun possible decimals (to give the maximun possible precision ProTools can give), I would get the accuratest percentage.
Remember that (going to math) some divisions doesn't end in 4,167%. The real figure is something like 4.166666666....etc, etc, etc.
But, I think you are right. ProTools will get the same ratio in 239,760,000 to 250,000,000 than 23976 to 25000.
The less number to write the better.

Jose Luis
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  #12  
Old 09-15-2005, 07:00 PM
Eric L Eric L is offline
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Default Re: PAL to NTSC speed change?

Quote:
Eric, I've clicked the link you provided on two systems but what I see is a page that has all the usual forum stuff, but without the thread. There is nothing to read. I thought maybe the link was broken or there was some other technical problem so I posted a quick formula to give an answer. That's all I meant and it was my mistake to not say so.
Richard, no problem. I wasn't sure what you meant, but now I know. Thanks. That's weird that it doesn't work for you. It works on my Safari. At the risk of sounding repetitive, maybe this link will work better.

Re: TC change from 29.97ND to 25
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  #13  
Old 09-15-2005, 08:48 PM
Richard Fairbanks Richard Fairbanks is offline
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Default Re: PAL to NTSC speed change?

I'm on Windows Explorer. The first link still gives me nill, but the second works perfectly! Very strange. I wouldn't have bothered with my post if I had known how much energy you had put into yours! Never mind, then.
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  #14  
Old 09-15-2005, 11:46 PM
David Sandwisch David Sandwisch is offline
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Default Re: PAL to NTSC speed change?

So from my reading of Richard's first post in this thread, NTSC speeds up to film speed and then film speeds up to PAL speed. This would indeed be a 4.1% pull up. My question is why do we do it that way when mathematically you could do it so there is only a .1% speed change from PAL to NTSC? I read the thread that Eric linked to and a post from sleadly seems to point to a .1% change. Obviously I am missing critical information on the exact method used to transfer PAL to NTSC, but thanks for the information from all of you.
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  #15  
Old 09-16-2005, 05:52 AM
Richard Fairbanks Richard Fairbanks is offline
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Default Re: PAL to NTSC speed change?

I can certainly understand your frustration. There CAN be 4.1 speedup or slowdown, but it is not a rule. There really aren't any hard rules. Part of it depends on if film projection is part of the equation and if so was it shot on film, if video then what conversion equipment is used and what artifacts the producers think are acceptable, costs, whatever. Sometimes there is no speed change whatsoever when converting between 25 and 29.97, sometimes there is .1%. Sometimes things are shot at 24fps and then projected at 25, or vice versa. There do not seem to be hard rules, we have to keep on our toes and communicate as much as possible with our clients.
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  #16  
Old 09-16-2005, 06:41 AM
CharlesL CharlesL is offline
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Default Re: PAL to NTSC speed change?

Quote:

Charles, what do you mean the NTSC version syncs up "almost"? How does it NOT sync up? To answer your question, if the picture conversion was done so that the program time remains the same it should not matter if you mixed against the PAL or NTSC version. All video decks want 48Khz audio so all you need to do is change the timecode setting of the session, find your offset to the master, and you're all set. "Almost" scares me.
Hi mate,
I mentioned "almost" partly because I suspect certain lip sync are not spot on because it was a dub and lips can never match word for word when the actual spoken dialog was in a different language.

Most lines do matches fine, so I believe by just changing the rate in session setup from 29.97DF to 25fps, it should be safe for me.

Only issue now is, when I stripe the NTSC decks, would the audio match the video or do i need to do a .1% or 4+.1% etc.. The NTSC video was supposedly converted from PAL, and I double confirmed with the Taiwanese studios that last frame of visual on their converted video matches my PAL version (original).

Anyway, I'll know next week once the Mandarin mix is done and when we bring in the rented NTSC decks.

Let me add a new question (unrelated, maybe.. sorry). Is there such thing as a "multi-system" Digital Beta Deck that can play and record in both PAL and NTSC formats??

Thanks & Regards,
[Charles]
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  #17  
Old 09-19-2005, 10:53 AM
RecRoom RecRoom is offline
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Default Re: PAL to NTSC speed change?

So if a client asks us for a 24 fps audio and we recorded at 30 fps, that doesn't require conversion on our part, correct? Other than changing the session format? We're doing this for an animated feature that hasn't been animated yet so there's no picture. I'm confused as to why the client would ask for this, but whatever, I've got to give it to him.

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  #18  
Old 09-19-2005, 11:08 AM
Richard Fairbanks Richard Fairbanks is offline
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Default Re: PAL to NTSC speed change?

Correct, unless there is a video-film pullup or pulldown between you and your clients. Other than the possiblility of a .1% change (for instance you worked to an NTSC dub while your clients are working at 24 fps) you should be okay.
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