Will the UHD HDR Revolution be Televised?

While the UHD world seems copacetic on the consumer front, UHD is a roiling mess of still-developing specifications and standards that threaten to obsolete the current generation of sets and create what industry insiders refer to as “Phase 2” UHD.

What every video engineer agrees upon is the potentially revolutionary affect HDR will have on the UHD market. While it may be difficult for consumers to see a difference between standard HD and UHD, there will be no mistaking the difference between HDR and non-HDR sets of any stripe. Images on HDR UHDs are brighter with significantly, if not geometrically, more detail in ultra-bright and ultra-dark scenes. Details heretofore washed out by a bright flash, such as an explosion or fire or bright sunlight, or hidden in the dark or shadows, suddenly become visible. The affect is startling and obvious to even the least educated eyes.

Everyone wants HDR. In fact, many folks have dubbed 2015 as the “Year of HDR.” The problem is standards – and isn’t it always? – and royalties.

The most visible HDR proponent (pun intended) is Dolby and its Dolby Vision standard. But Vizio is the only current TV supplier to license Dolby Vision. So far only Warner Bros. is using Dolby Vision to master its coming UHD Blu-ray content.

As a result, maybe penurious TV makers and Hollywood studios are pursuing their own HDR solutions. Most of these HDR variations, including Dolby Vision, use two SMPTE specifications as foundations:

  • ST-2084, aka HDR EOTF (Electro-Optical Transfer Function), which is included in most color specs (BT709 and BT2020) and ensures the steps coded in perceived brightness remain even and not bunched together
  • ST-2086, aka HDR Mastering metadata, which ensures HDR content can be viewed on standard dynamic range displays

Ironically, Dolby developed both these now open specifications.

The only other HDR specification that everyone seems to agree upon is HDMI 2.0a, released last month. Whoopee!

But just because multiple buildings use a specific cement formulation for their foundations doesn’t mean that all the structures will look alike, contain the same number of floors, the same sized doors or windows, the same ceiling heights, the same electrical system, the same plumbing fixtures – you get the idea.

There is a veritable alphabet soup of organizations – the ITU, the EBU/DVB, SMPTE, MPEG – all trying to adjudicate and establish cogent and broadly applicable HDR standards. Each of these acronymic bodies are trying to herd proposals from varying UHD makers, chipmakers, and technology developing and content companies into some sort of color gamut, color/tone mapping, coding, brightness level, transcoding, frame rate, bit-rate, compression, encoding, decoding, copy protecting and mastering specifications adoption detente.

I had planned to list some of these specification conflicts, but they’re the stuff that gives mere mortals glazed-over eyes and nightmares of high school advanced calculus tests.

Also not surprisingly, some of these HDR constituencies are simultaneously working together and against each other.

For instance, there’s the newly formed UHD Alliance, a 10-member group aiming to establish broad UHD standards, but more to serve as a UHD marketing and evangelizing engine. But 40 UHD/HDR entities are proposing a more technically-bent UHD Forum, whose goal is to create a complete end-to-end UHD specification ecosystem, with a priority on UHD broadcast and content creation.

Some of the UHD Forum members also are in the UHD Alliance – Dolby most prominently – and the UHD Forum wants to work closely with the UHD Alliance as each pursues its own standardization interests.

Uh huh.

Stuck somewhat in the middle of this HDR hullabaloo is the Blu-ray Alliance, which released final Ultra HD Blu-ray specifications on May 12. These specs merely include SMPTE 2084/2086 as required and Dolby Vision as an option.

As things stand right now, there doesn’t seem to be agreement on anything HDR-related – not even SMPTE 2084/2086. Dolby is defining and including multiple layers of HDR – its native 12-bit color/10K-nit format plus a 10-bit (HDR10, whose implementation is still being finalized) – to hopefully playback non-Dolby Vision HDR content on a Dolby Vision-enabled UHD. But it is unclear what proprietary HDR-mastered content will look like on a UHD that isn’t equipped with that proprietary HDR method. At best, HDR content played on non-matching HDR displays, or even non-HDR SDR displays, will look…okay.

To throw another log on the HDR fire, there’s the potentially fatal issue of photosensitive epilepsy. How do you even test for such a thing without endangering the test subjects? Great – TV that can actually kill you if you watch it.

Of course, no UHD maker wants anyone outside their labs to know anything about this whole pending HDR revolution. Who wants to tell their customers that the UHD they’re spending $2,000 – $10,000 today will likely be obsolete next year?

This may be the year for HDR, but it could be two, three years before the HDR dust settles – and we’ll be able to see the dust particles on our UHDs.