1.78 in Version 2.12.6

Anything and everything to do with DCP-o-matic.
robn
Posts: 5
Joined: Sat Feb 10, 2018 1:19 am

Re: 1.78 in Version 2.12.6

Post by robn »

With having 1920x1080 back as an (advanced) option you can work around the scaling problem
of burnt-in bitmapped subs with for for example Blu-ray material. See:

https://dcpomatic.com/mantis/view.php?id=1246

Now I always juggle with an extra 96% X-scaling factor (1920/1998) to get things approx. correct.
Having the DCP-container equal to the size of the source avoids the problem ..

(yes, it would be good to think of a better/permanent solution, but I've been busy .. :-)
Carsten
Posts: 2794
Joined: Tue Apr 15, 2014 9:11 pm
Location: Germany

Re: 1.78 in Version 2.12.6

Post by Carsten »

Well, not the best solution to that problem. Keep in mind, these DCPs can cause issues on real servers. No trouble if you create them for your own, but I would not let a 16:9 container into the wild. That said, 16:9 containers are probably a bit less risky, since a lot of ads used to be converted into 16:9.

ISDCF is currently preparing a document that constraints SMPTE allowed DCP options into a 'best mastering practice' recommendation. Among it, only flat or scope containers. Full container only for testing purposes, not to play to the public.

Not sure if I understand that scaling issue at all. When playing a bluray, these subs are laid out to fit the 1920/1080 raster. When we create a DCP, we should use the 1920/1080 source with the subs inserted exactly the same way, then pad to 1998 with black. If we don't want to pad, but zoom to a full 1998*1080, the placement of the sub bitmaps doesn't need to change? I guess I need to do my own tests to see the issue. Again, admitted, I personally see general subtitles as a clumsy aid to help understanding, and am not inclined to see any beauty in their appearance, as long as I can read them. So, forgive my ignorance there... ;-)

- Carsten