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tmeiczin / opendcp

Created digital cinemas packages (DCP)
http://www.opendcp.org
GNU General Public License v3.0
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4K DCP wavelet levels #272

Open alexfalk opened 9 years ago

alexfalk commented 9 years ago

4K JPEG2000 encodings in opendcp always is using five wavelet levels. DVS Clipster and others use six. If you combine elements with two different wavelet levels for VF-DCPs you can run into playback problems. Is there an option to switch to six wavelet levels for 4K?

tmeiczin commented 9 years ago

The specification allows up to a maximum of 6 for 4K. It does not require 6. If a particular server is having issues, then it sounds like a problem on equipment side. I would recommend discussing the issue with the vendor, if possible. Having said that, there is no particular reason not to increase the number of resolution levels to 6 in a future release.

alexfalk commented 9 years ago

Dear Terence, it's more a feature request than a bug report. All renderings out of opendcp_j2k in 4k are fine, but ISDCF recommends not to combine elements with different wavelet levels. In DCP distribution it is common to make versions by combining elements encoded by different systems. A big amount of studios are mastering with DVS systems - which are fixed to six wavelet levels in 4K. So JPEG2000 encodings by opendcp cannot be versioned by DVS systems and others. De facto on current Doremi IMBs we are seeing green flashes while combining elements from opendcp and DVS - with other servers not. Distributors are concerned rolling out DCPs suffering this problem. You're right it is a problem of the manufacturer - but i think it is worth to have a switch for that. Or maybe something in the source code to modify. Just to know that problem cannot occur.