Yet Another 4k HDR Ultra HD logo? Really?
Yet Another 4K HDR Ultra HD Logo? Really?
By Bob Campbell, Eurofins Digital Testing 2017
2017 will be a significant year for High Dynamic Range (HDR), with a huge number of TV manufacturers announcing displays that will support multiple HDR technologies. Major OTT services have started delivering some HDR content from studios, but perhaps more significantly, regional broadcasters are preparing to deploy services that make use of HDR, and are even starting trials with HDR versions of their original content.
For the next generation of video services, HDR is considered more important than simply the increase in resolution from HD to Ultra HD because of the significantly improved viewing experience it delivers. “Many people who have experienced both, say that HDR has a greater impact on picture quality than 4K" (BBC, 8th December, 2016).
Why? Because there’s a limit to how far increasing resolution alone can be perceived by the naked eye, within a typical living room environment. While 4K and even 8K may make a difference on very large screens, in some scenarios, “High Dynamic Range will offer a step-change in quality to viewers, making pictures more realistic and more immersive” (BBC). This is achieved on displays that remain practical for the majority of homes, because HDR and Wide Colour Gamut (WCG) - which typically go hand in hand - allow a greater fidelity of contrast, and a deeper colour palette for the given resolution. However, “in order for HDR programmes to be enjoyed in the home, a complete broadcast infrastructure must be in place” (BBC) and most importantly, devices that actually decode the broadcast and broadband signals.
Today, the vast majority of 4K TVs are rarely used to display UHD content, let alone HDR content. There are two typical ways they might. The first way is via an HDMI connection from a UHD BluRay player or Set-Top-Box (STB) from one of the few pay TV companies offering UHD. The second way is via an OTT application such as Netflix or Amazon Prime installed on one of the few models of Smart TVs that have compatibility with UHD/HDR content (most Smart TVs do not support UHD/HDR and even some that do will not carry the necessary application). Broadcasters have no way of directly reaching UHD HDR TVs via free-to-air terrestrial or satellite broadcast, and OTT service providers have their work cut out trying to determine which TVs might support their new HDR service. As for the consumer, what chance do they have of navigating through this mess?
While there are many UHD, 4K and HDR logos and different terms in use out there – from both individual manufacturers – and industry consortia, none of them indicate whether the TV is able to decode UHD/HDR content delivered via broadcast, nor do they offer an assurance that the TV is capable of receiving via broadband UHD/HDR content in a standard format. The current Digital Europe UHD logo does not cover HDR at all.
All this has arguably held back the deployment of 4K HDR Ultra HD services and resulted in considerable confusion for consumers. If you’ve invested in an HDR TV before now, there’s a chance you might not be able to watch HDR broadcasts when they are launched in the future. The BBC intends to use the Hybrid Log Gamma (HLG) standard (co-developed between BBC and Japan’s NHK) for HDR services - and is currently trialling Planet Earth II in HDR on its catch up service iPlayer. Other services are using the Dolby Vision HDR system and yet others are using the HDR-10 system (both based on the more simple PQ10 system – see the Ultra HD forum guidelines for a detailed explanation), but many TVs only support one of these HDR systems!
Bringing some order to the chaos the very recently announced DVB specification for Ultra HD, which includes two HDR formats (specifically PQ10 and HLG) offers to standardise the technology in a way that all parts of the broadcast ecosystem can make use of. The expected incorporation of the DVB specification into regional requirements will, we believe, kick-start the adoption of HDR in a wide range of services. So far the UK’s DBook 9 has been announced and we expect other regional technical specifications to follow this lead. This along with existing HbbTV and DVB DASH specifications enables a wide range of broadcast and broadband OTT services to reach compliant HDR devices.
A TV carrying the new 4K HDR Ultra HD Logo will be compliant to HDR relevant elements of these specifications, and so must display HDR if connected to a secondary HDR capable device over HDMI and should also support broadcast and broadband HDR services natively (if those services also comply with these open standards).
The 4K HDR Ultra HD Logo is intended to broadly cover 4K HDR Ultra HD receivers, and allow manufacturers to differentiate on performance and additional features. It does not attempt to define requirements on specific maximum brightness or black levels. This Logo is not intended to compete with alternative “premium” UHD approaches such as Dolby Vision or the UHD Alliance but is indeed complementary.
Therefore, there really is a need for a new Logo for 2017 devices that will support HDR services being planned today, and in the future. By referencing open standards such as from DVB and HbbTV it encourages interoperability and fills a current gap, which isn’t addressed by proprietary manufacturer logos and existing consortium logos. Finally the 4K HDR Ultra HD Logo is backed by comprehensive test materials and a rigorous certification regime operated by a respected independent testing specialist.
The aim is to track the requirements of evolving deployments of HDR broadcast and broadband services in other regions in the future. The expertise of Eurofins Digital Testing and our extensive experience in creating test materials and operating certification services for the industry should provide confidence and encourage widespread adoption of the 4K HDR Ultra HD Logo. Contact us for more information.