Is it possible to change audio/video sync in s DCP?

Anything and everything to do with DCP-o-matic.
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Alex Asp
Posts: 69
Joined: Mon Apr 11, 2016 3:59 am

Is it possible to change audio/video sync in s DCP?

Post by Alex Asp » Tue Mar 12, 2019 9:50 am

I have made DCP which is slightly out of sync - about 3 - 4 frames.
Is it possible to fix it without redoing a dcp?
Preferably by single change in CPL, PKL or other places?
I know it might render the DCP invalid, but a few keystrokes are better than few hours of rendering.

carl
Site Admin
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Joined: Thu Nov 14, 2013 2:53 pm

Re: Is it possible to change audio/video sync in s DCP?

Post by carl » Tue Mar 12, 2019 4:43 pm

You could load the DCP into DCP-o-matic, adjust the audio delay and re-make the DCP; DCP-o-matic ought to do that fairly quickly.

Alternatively you could edit the CPL and adjust the <EntryPoint> in either the MainPicture or MainSound to advance that thing. This would then require you to remake the hashes in the PKL and ASSETMAP.

Alex Asp
Posts: 69
Joined: Mon Apr 11, 2016 3:59 am

Re: Is it possible to change audio/video sync in s DCP?

Post by Alex Asp » Wed Mar 13, 2019 5:18 am

Thanks Carl,

There are two questions and one feature request now:
1. How do I redo the hashes without being a programer.
2. Where do I adjust the delay. In Preferences?

Can you add an interface for adjusting sync to DOM?

Alex

Carsten
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Location: Germany

Re: Is it possible to change audio/video sync in s DCP?

Post by Carsten » Thu Mar 14, 2019 2:21 pm

You can already do that in DCP-o-matic using the delay option under 'audio'.

- Carsten

carl
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Re: Is it possible to change audio/video sync in s DCP?

Post by carl » Thu Mar 14, 2019 2:23 pm

The delay is in the Audio tab of the content page. DoM doesn't yet provide any means to recalculate DCP hashes.

Adjusting sync by manipulating EntryPoint is quite a niche feature, I think. There may, at some point, be time to make a tool which manipulates DCPs without any sound/picture coding (adjusting CPLs, fixing hashes, signing, that sort of thing).

Carsten
Posts: 1161
Joined: Tue Apr 15, 2014 9:11 pm
Location: Germany

Re: Is it possible to change audio/video sync in s DCP?

Post by Carsten » Thu Mar 14, 2019 9:25 pm

Carl - what would happen if you e.g. load a DCP with broken hashes into DCP-o-matic, then (re)create it? Yes, it would be a new DCP, not 'the same', but...


- Carsten

carl
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Re: Is it possible to change audio/video sync in s DCP?

Post by carl » Thu Mar 14, 2019 9:31 pm

It should work AFAICS. Though it would recreate all the MXFs, I think.

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