Juddery Motion - Help!

Anything and everything to do with DCP-o-matic.
Andy Jenkin
Posts: 4
Joined: Fri Apr 08, 2016 3:33 pm

Juddery Motion - Help!

Post by Andy Jenkin »

Hi there,

I've been converting a load of ProRes short films into DCPs and have mostly had great success (thanks!), however there are two particular ones that I'm having a specific problem with. When playing back they are juddery, but much more continuously than in a 25-24fps conversion scenario. It's almost like every other frame has been swapped with the previous, it's quite strange to watch, almost a slow-motion or 'dragging' type effect.

What's confusing is that the two original files are seemingly the same as all the others I've made successfully - ProRes 422, 25fps, linear PCM audio (see screenshot); the only real difference is their size as they're a little larger, around 16-18Gb. Obviously the motion issue is not present in either of the original files.

I'm using a Mac Mini quad-core i7 with SSD, could it be something to do with the SSD? Is there anything else I should be checking/trying?

I really appreciate any pointers anyone can give.

Thanks,

Andy
Screen Shot 2016-04-14 at 12.25.47.png
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carl
Site Admin
Posts: 2362
Joined: Thu Nov 14, 2013 2:53 pm

Re: Juddery Motion - Help!

Post by carl »

That's odd. What are you playing the DCP back with? Could it be the player malfunctioning?

Can you make a small snippet of the source file which still exhibits the problem? If so, you could send it to me and I can investigate.

I can't see how the SSD would have anything to do with it.
Carsten
Posts: 2665
Joined: Tue Apr 15, 2014 9:11 pm
Location: Germany

Re: Juddery Motion - Help!

Post by Carsten »

I can only suggest to redo this specific file from scratch. Maybe reset DOM prefs before. Do you use network encoding servers?

Never had something like this. If it doesn't go away, try to create an image sequence from the Prores file and use that as source.

- Carsten
Andy Jenkin
Posts: 4
Joined: Fri Apr 08, 2016 3:33 pm

Re: Juddery Motion - Help!

Post by Andy Jenkin »

@carl

I'm using Doremi DCP2000 servers and Christie CP2000 projectors mainly, but it exhibits exactly the same issues on other projector/server combos also. And as I said it's not the source files that are the problem, they play fine, only when made into DCPs. I've remade both files from scratch, one twice and one three times, all with the same results.

@Carsten

I will try making it from an image sequence, I hadn't thought of that. I'll let you know my results.

Anyone else with similar experiences?
carl
Site Admin
Posts: 2362
Joined: Thu Nov 14, 2013 2:53 pm

Re: Juddery Motion - Help!

Post by carl »

I'm using Doremi DCP2000 servers and Christie CP2000 projectors mainly, but it exhibits exactly the same issues on other projector/server combos also.
OK, it's not that then ... I thought you might be using a PC player.
And as I said it's not the source files that are the problem, they play fine
Indeed, but there may be something about the source files that is triggering a bug in DCP-o-matic. If you can reproduce the bug with a smaller source file, then send it to me, I can try to debug DCP-o-matic and remove the problem.
Andy Jenkin
Posts: 4
Joined: Fri Apr 08, 2016 3:33 pm

Re: Juddery Motion - Help!

Post by Andy Jenkin »

Hi Carl,

Ah I misunderstood, that makes perfect sense. I will look into doing that. In the meatime, I'm trying to make a DCP out of an image sequence and having difficulty using the 'Add Folder' option, as when I do it throws up an error saying there is no AssetMap file.

Any ideas how I can make this work?

Thanks,

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

Re: Juddery Motion - Help!

Post by carl »

What version of DCP-o-matic and what types are your files?
Andy Jenkin
Posts: 4
Joined: Fri Apr 08, 2016 3:33 pm

Re: Juddery Motion - Help!

Post by Andy Jenkin »

Hi Carl,

DCP-o-Matic version 2.6.3 git 0c74579407

Image files are JPG

Thanks,

Andy
carl
Site Admin
Posts: 2362
Joined: Thu Nov 14, 2013 2:53 pm

Re: Juddery Motion - Help!

Post by carl »

I think you're hitting a bug in 2.6.3; try 2.7.1 and see if that's any better.
mytbyte
Posts: 20
Joined: Fri Apr 08, 2016 8:03 pm

Re: Juddery Motion - Help!

Post by mytbyte »

@andy: are you sure there are absolutley no other files in the folder except the JPGs? No thumbnails or such? no mac dot files?...I think that may be what breaks the folder import ...