audio sync problem with 23,976 and other fps

Anything and everything to do with DCP-o-matic.
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marcelmax
Posts: 39
Joined: Sun Mar 25, 2018 6:55 pm

audio sync problem with 23,976 and other fps

Post by marcelmax »

got ProRes Files with 23,976 fps and 24,910. Made DCPs with 24 and 25, then exported to ProRes again. The new ProRes files are out of sync (a lot, some sec) and the DCP, too. (At least the 24,910 > 25, dcp Player is not playing that accurate to be absolutely sure with the 23,976 > 24 film)
Any idea?

... in the meanwhile I found out, that all videos where the source was not 24 or 25 exactly have this issue. Sometimes it's only the exported ProRes, sometimes it's both, DCP and ProRes.

DOM 2.14.54
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carl
Site Admin
Posts: 2338
Joined: Thu Nov 14, 2013 2:53 pm

Re: audio sync problem with 23,976 and other fps

Post by carl »

Hi there

It looks like you might have set the frame rate of your content in the "Timing" tab. It's very important NOT to do that unless DCP-o-matic has detected the frame rate of your content incorrectly.

Set the rate in the DCP -> Video tab to be the rate that you want the output to be, and DCP-o-matic should take care of the rest.
marcelmax
Posts: 39
Joined: Sun Mar 25, 2018 6:55 pm

Re: audio sync problem with 23,976 and other fps

Post by marcelmax »

Thanks.
Still have trouble with sync. I did as you said and left the fps in Timing as detected (23,967), set fps in DCP on 24. The DCP is now in sync, but exported ProRs not.
the other case: DOM does not detect the correct framerate (24,91 as MediaInfo said), so I corrected it in Timing, DCP is set on 25. Both, the rendered DCP and exported ProRes are out of sync.
All look fine in DOM preview.

I am not sure, but I remember, a year ago with a recent vers. I had those framerates, too, and there was no trouble. DOM just speeded up or slowed down a bit.
IoannisSyrogiannis
Posts: 128
Joined: Mon Nov 13, 2017 8:40 pm

Re: audio sync problem with 23,976 and other fps

Post by IoannisSyrogiannis »

...DOM does not detect the correct framerate (24,91 as MediaInfo said)...
Something is not correct with that frame rate at the first place.
It seems more like a frame rate taken out of a phone camera than a production ProRes and suggests variable frame rate.
You will probably need some other tool first, before you "feed" that video to DCP-o-matic.
marcelmax
Posts: 39
Joined: Sun Mar 25, 2018 6:55 pm

Re: audio sync problem with 23,976 and other fps

Post by marcelmax »

You might be right. I'll check this one video with 24,91 fps.
But there seems to be a problem with lots of the exported ProRes. Another one is out of sync, and there was nothing with the frame rate. Source file 24, DCP 24. Nothing special. I am afraid I have to check all exported video files, created by DOM.
That's weird.
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