Film-Tech Forum ARCHIVE: 23.976 to 24 FPS audio conversion in Cute DCP or DCP-o-Matic?

This is topic 23.976 to 24 FPS audio conversion in Cute DCP or DCP-o-Matic? in forum Digital Cinema Forum at Film-Tech Forum ARCHIVE.

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Posted by Leo Enticknap (Member # 534) on 03-11-2017, 08:50 PM:

I am trying to make a DCP from a set of DPX frames and a .WAV audio file. The DCP begins in perfect sync, and gradually drifts, such that by the end (running time is 25'41"), the pix appears to be between 1 and 2 seconds ahead of the audio.

The person who gave me the files to make the DCP from warned me that the audio file might have been mastered at 23.976, and so this seems to me to be the most likely explanation for the sync drift. The video, obviously, is 24.

The two DCP creation tools I have are the Cute DCP plugin for Adobe Premiere, and DCP-o-Matic. I have scoured the menus and documentation of both for a 23.976 to 24 conversion facility, but can't find any.

The next thing I'm thinking of trying is importing the audio into Adobe Audition and stretching it to match the running time of the video, apply that to the DCP and re-render. But doing that would probably involve some messy math, figuring out how long the final, partial second of video is, and translating that into a precise stretch factor.

Just before I do that, I was wondering if anyone knew of any easier, one-click solution in Cute or DCP-o-Matic that I missed?

Posted by Carl Hetherington (Member # 7107) on 03-12-2017, 01:34 AM:

Hi Leo,

Import both to DCP-o-matic, select the WAV file, go to the Timing tab, enter 23.976 for "video frame rate" then click "Set".

Then the DCP should be made correctly. The "video frame rate" for non-video files means "the video frame rate that this content was made to fit with"

Let me know if it doesn't work.

Posted by Leo Enticknap (Member # 534) on 03-12-2017, 04:30 AM:

Sorry - didn't occur to me, as I thought this setting only applied to video content. Will try this and re-render - many thanks as always.

Posted by Carl Hetherington (Member # 7107) on 03-12-2017, 04:43 AM:

It's far from obvious. Alternatively specifying the DPX sequence as 23.976 when you import it should work.