The Ultra HD Forum stuck to tradition by publishing a set of new technical guidelines at NAB, six months on from its IBC masterclass. Regardless of how we approach it, summarizing such a chunky document (over 180 pages) in one article is impossible, so the Forum was on hand at NAB to outline a handful of significant components and highlight how it attempts to clear the ever-muddying waters around Ultra HD in the industry.
As well as laying out a strategy for 8K, Ultra HD Guidelines 2.0 introduces distinctly separate guidelines for the concepts of foundation technologies and enhancements. Backwards compatibility is key, simply put it must work with old stuff. “Some people even thought Ultra HD would break their old screens,” noted the Forum’s Ian Nock, a video technology strategist, adding that content-aware encoding and simulcast as base features are important aspects of the updated guidelines.
The Forum has therefore begun the process of evaluating 8K, but Nock was wary of getting carried away and assured us the Forum is approaching 8K in a very pragmatic manner – estimating at least a decade before the 8K evaluation process reaches anything resembling finality. He cited Japanese national public broadcaster NHK at a neighboring stand having just launched the first 8K channel – while poking a little fun at just how long the launch has taken.
Back to the guidelines. There have been further expansions on dynamic metadata, for example adding dynamic HDR metadata to foundation UHD – addressing the limitations of HDR10 and PQ10. Dynamic metadata in this sense refers to metadata that describes the image at a much finer temporal granularity, scene-by-scene or even frame-by-frame and produces significantly more information about the mastering and creative intent of the scenes.
The document’s foreword addresses an important question. “Why did we drop our different phases? Because people are now getting serious about Ultra HD and want to have a holistic view of all the different technologies applied to UHD into one single document. This work represents over four years of collaborative effort by all those who have contributed to the Guidelines Work Group.”
It’s worth remembering that while the Ultra HD Forum handles the infrastructure side, the Ultra HD Alliance approaches the technology from the camera and TV angles, yet it is true that the two groups are gradually aligning. Nock agreed there is a certain degree of harmony, but the fundamental differences are enough to dismiss the notion of a potential Ultra HD Forum-Alliance merger down the line.
We should quickly touch base on the masterclass staged by the Forum at IBC 2018, considering feedback from recent marquee events such as the 2018 FIFA World Cup where phase A implementations had been put to test at some scale. Phase A provides quite a wide choice to cater for different flavors of UHD, but for the World Cup and other recent major sporting events in practice did mean 4K 2180p resolution, WCG to the more advanced 10-bit BT.2020 specification and HDR to either the PQ or HLG standards.
But for all the confusion around Ultra HD among content creators and others in the industry, let alone consumers, the fact UHD is developing faster than HD (Eutelsat estimates 155 UHD channels in total worldwide today) is testament to the work being done by the Forum, among others.
The full guidelines can be viewed in all their glory here.