Best Way to print a pulled down mix

[nlc201]

Hey gurus,

I was wondering if I could get some advice.


I'm currently working on an animation project that is being animated at 24 fps. It is a musical piece and we are providing all audio content, delivering it to the animator and then doing audio post. The workflow has been fine with everything coming back to us with no sync problems working with their 24 fps reference QT videos.


However, the initial plan to output the piece to 35mm film has been scrapped which is why we were all adhering to 24 fps instead of an NTSC frame rate in the first place. Now, the final master for this will likely be on HDCAM SR at 23.976 fps. It's easy enough for us to pull down both the video and audio to work at that frame rate. However, when it comes to layback, is the best option still to go analog into the deck since we're technically working at a 47,952 Hz sampling rate?


I've done a few tests with printed mixes using various time shifting plugins to pull the mix down 0.1% and the results have been less than stellar with a fair amount of artifacts. So, is an analog transfer during layback still the way to go? Is it possible to clock our PT SYNC HD unit to house tri-level sync and still be able to pull down the sample rate while maintaining a good lock?


Thanks so much in advance!

[Whitecat]

I would simply resample it all... it should be artifact-free if you use a high-quality SRC process like the iZotope one in Wave Editor. You'd be staying digital.

Anyway, all you need to do is convert the 48000 khz output to 47952.04187 khz (but don't resample it) - then convert the resulting bit back to 48000 with resampling. Et voila. Problem solved. There will be a very slight pitch difference but there should be no artefacts if the SRC is good.

[soundshaper]

This is interesting. Why does the sample rate change with the frame rate change? I figured a second is always a second regardless of how many frames there are. And samples aren't locked to frames, right?

[hummer]

A second is always a second, but if you're slowing down the video, you need to slow down the audio as well.

+1 for resampling.

[soundshaper]

Ok, so the video frame rate was not converted, just pulled down.

[Etch-A-Sketch]

Originally Posted by soundshaper

I figured a second is always a second regardless of how many frames there are.

Unless you are doing 29.97 for example... a running time of 1 hour on 29.97 is 1 hr and 3.5 seconds of absolute time. That is why they created "Drop Frame". Drop frame TC drops two frames every minute, except every tenth minute, in order to stay in sync with "wall clock" or absolute time.