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1080/25p to 1080/24p conversion

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chrispy
1080/25p to 1080/24p conversion
on Jun 25, 2007 at 7:03:50 am

Hi,

If I've edited a HD 1080/25p programme and decided that we wanna do a film release, is there a way to convert the 25p to 24p ?

And how would the audio be affected ?

Appreciate any advise.

-chrispy


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Jeremy Newmark
Re: 1080/25p to 1080/24p conversion
on Jun 25, 2007 at 8:56:08 am

Chrispy,

Your best option here would be a Teranex for the video and have a seasoned audio post house slow down the audio and pitch shift it for you.

best regards,

jeremy


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Jeremy Newmark
Re: 1080/25p to 1080/24p conversion
on Jun 25, 2007 at 9:30:32 pm

[Jeremy Newmark] "...for the video and have a seasoned..."

I appologize, that "and" should have been an "or"

best regards,

jeremy


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gary adcock
Re: 1080/25p to 1080/24p conversion
on Jun 25, 2007 at 1:58:41 pm

[chrispy] "If I've edited a HD 1080/25p programme and decided that we wanna do a film release, is there a way to convert the 25p to 24p?
And how would the audio be affected ?"


2 ways to do this, and NO a teranex is not needed

Open the file in Cinema Tools and use the conform function to get 24- your audio will slip a small amount, but it is not noticed by most.

2nd way extract the audio file Before conversion, then open the file up after the CT conform and re-sync your original audio. (not as difficult as it sounds)




gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows


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Jeremy Newmark
Re: 1080/25p to 1080/24p conversion
on Jun 25, 2007 at 9:44:05 pm

You need to keep in mind that if you go the Cinema Tools route, you are essentially slowing it down around 4%, so the audio does need to be handled properly. If you go the more expensive Teranex route, your audio will match the 25p cut and you will not have to worry about it.

As with all methods, there are pros and cons to each. The Cinema Tools route is cheap but requires more work to be done on the audio end, if you want it to match your original cut. Where as the Teranex route is more expensive but requires no re-working of the audio. So if a lot of work has gone into the audio and the mix, then this option may be worth the money.

best regards,

jeremy


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gary adcock
Re: 1080/25p to 1080/24p conversion
on Jun 25, 2007 at 10:26:16 pm

[Jeremy Newmark] "If you go the more expensive Teranex route, your audio will match the 25p cut and you will not have to worry about it. "

Jeremy

My teranex does not support 24p at all, and neither does the AXR or VC100 product lines to the best of my knowledge.

to my limited knowledge, teranex has never done standards conversion like you find on Ukon and Alchemist systems. Which teranex system do you use for this.

"You need to keep in mind that if you go the Cinema Tools route, you are essentially slowing it down around 4%, so the audio does need to be handled properly."

yes and that is why I posted an easy workaround of re-syncing the audio track.

interesting but most people do no notice the speed changes that occur between 24 and 25
conforms unless they are musicians



gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows


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chrispy
Re: 1080/25p to 1080/24p conversion
on Jun 26, 2007 at 1:38:44 am

Hi Gary and all,

Just to confirm, if I take the Cinema Tool route, does it change the speed of the video when going from 25p to 24p or does it perform some kind of intelligent pulldown to remove a frame off every second ?

And if this is a full length feature film, any idea how long it'll take ?

-chrispy


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Jeremy Newmark
Re: 1080/25p to 1080/24p conversion
on Jun 26, 2007 at 11:15:46 am

Chrispy,

When you go the Cinema Tools route, it does change the speed of the video. The conform process is very quick, to roughly explain it, Cinema Tools is basically just re-writing a header file that tells quicktime to play the video out at a different frame-rate, so it is done almost instantaneously.

best regards,

jeremy


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Jeremy Newmark
Re: 1080/25p to 1080/24p conversion
on Jun 26, 2007 at 10:46:06 am

[gary adcock] "My teranex does not support 24p at all, and neither does the AXR or VC100 product lines to the best of my knowledge.

to my limited knowledge, teranex has never done standards conversion like you find on Ukon and Alchemist systems. Which teranex system do you use for this."


Hi Gary,

In my world I work with 23.976p and 25p not true 24p, but it was a Teranex rep that told me that the AXR product line can do true 24p <-> 25p conversion. If this is not the case, then I apologize for spreading mis-information. I do not own a Teranex system, you do, so you would no better than I. When I post information I try to make sure that it is info I've either learned from personal experience or trusted sources. In this case the info may be wrong and if so, I'm sorry.

That being said the Ukon may be another option, I don't have much experience with Snell & Wilcox products, but I do believe that the Ukon can input 23.976p and 24p and output it to 25p, where as the HD version of the Alchemist is traditional standards conversion frame rates only, no 23.976p or 24p support. Please correct me if I'm wrong.

best regards,

jeremy


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gary adcock
Re: 1080/25p to 1080/24p conversion
on Jun 26, 2007 at 1:12:37 pm

[Jeremy Newmark] "where as the HD version of the Alchemist is traditional standards conversion frame rates only, no 23.976p or 24p support. Please correct me if I'm wrong."

Correct, I was using the Alchemist as a referance to standards conversion, not that specific frame rate 24/ 23.98 - which it does not handle.

"In my world I work with 23.976p and 25p not true 24p, "

Just like everyone else, I too I avoid using 24.0 in the US if any way at all possible, there are too many issues when everything works the same way at 23.98





gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows


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