Delivering UHD/HDR: Rising to the challenge of increasing demand

Spend a little time speaking with Thierry Fautier – who as both president-chair of the Ultra HD Forum and VP video strategy at Harmonic, is extremely well-positioned to comment – and you will quickly get the impression that the implementation of UHD and HDR falls into several distinct stages.

We are now beyond the initial phase that preceded global sports events such as the 2018 FIFA World Cup and are in what he describes as an “extended period of growth” in which adoption is accelerating across platforms.

Not that the present moment is without challenge given the pandemic-related restrictions imposed on streaming services in Europe in order to maintain bandwidth. Nonetheless, the UHD Service Tracker launched by the Ultra HD Forum in April reveals a current total of 146 UHD services worldwide – up from 50 in 2017. Some 73% of these services are linear, while 45% are also being delivered with HDR.

With 10% of global subscribers having access to a UHD service of some kind, it is not hard to see why “a lot of service providers are thinking about how best to produce and deliver” their UHD/HDR content, says Fautier.

‘High-value events’
Geoff Stedman, enterprise media strategist at AWS Elemental, highlights the greater adoption by OTT service providers – as opposed to traditional broadcasters – at this point, and observes that “most of our customers are not seeing the value of delivering 24x7 pay TV channels in UHD. However, there is interest in UHD for high-value events, especially for OTT streaming.”

Of course, sports continues to be a real trailblazer in this regard. Stedman points to content rights holders and sports organisations using AWS to support their live video streaming, including UHD channels. Specific recent examples include the deployment by Fox Sports of AWS Elemental Media Services and the Amazon CloudFront CDN as part of the infrastructure to support the live streaming of the Super Bowl XIV.

Ongoing video processing innovations can be made available quickly by “taking advantages of new capabilities” in the cloud. For instance, says Stedman, “we are constantly moving ahead to take advantage of the progression in CPU power, which is a huge benefit to customers who cannot do that with on-premise investments. A good example of this is our launch of HEVC UHD encoding and Enhanced Visual Quality with AVC.

”These capabilities give our customers the ability to encode and transcode at UHD resolutions without any upfront investment. Similarly, we’ve added support for HDR10 and Dolby Vision, along with integrated tone mapping for SDR colour derived from an HDR signal. These innovations allow our customers to easily add high-quality media processing and delivery of UHD/HDR content, all in a pay-as-you-go model without any upfront capital required.”

Looking ahead, Stedman indicates that AWS Elemental will continue to address demand for 4K content in two main areas. “The first is sporting events, where viewers often purchase their 4K TVs specifically to watch their favourite sport on a big screen in high-resolution,” he says. “The second area where we see demand for 4K is with VOD movie content, especially from consumers who have put in a large screen and surround audio to maximise the movie experience in their homes. Our focus is to enable content owners and distributors to provide a high-quality video signal at the lowest possible bit-rate to create the best experience for consumers and yet be cost-effective for content distributors.”

‘Diversity of workflows’
With UHD becoming well-established, Thierry Fautier draws attention to growing activity around the implementation of two specific HDR technologies – HDR10 and HLG (Hybrid Log-Gamma), the latter a backwards-compatible high dynamic range standard that was jointly developed by the BBC and NHK.

It is increasingly apparent that “there is not much traction now” around the idea of UHD without HDR, not least because “content providers and consumers want to be able to see something substantially different,” says Fautier.

Watch Tech Expert: UHD

Nonetheless, there will continue to be “a real diversity of workflows” for the foreseeable future in terms of delivering UHD/HDR content, while efforts to support higher frame rates will continue to ramp up: “I think that is something that a lot of people are thinking about and working on at the moment.”

The Ultra HD Forum also tracks another component of new broadcast services – Next Generation Audio (NGA) – but it is evident that this is trailing behind the adoption of UHD and HDR for now. According to the aforementioned April 2020 Ultra HD Forum data, only 22% of 146 services currently have an NGA component, although Fautier is optimistic that “as services evolve more and more will implement NGA”.

At-home production
As well as recognising that content creators will continue to work “in a variety of ways in terms of UHD production”, Grass Valley is also acknowledging that there is likely to be a spike in UHD work undertaken out of the studio, “for example, flypacks, mobile set-ups or at-home production. But of course, there will still be people coming to us who want to build trucks that are able to support the highest-quality [of UHD production],” says CTO Chuck Meyer.

This list of priorities is reflected in a number of recent product launches, including the spring introduction of the new GV K-Frame XP video production engine. Developed to enable consistent across “multi-format environments”, the K-Frame XP incorporates true single stream, full raster and 4K processing at 2160p. The result, says Meyer, is an engine that “removes compromise in 4K UHD”, with no reduction in I/O count in 4K UHD; no reduction in M/Es, keyers or DPMS in 4K UHD; and no change in operator workflow.

Whilst understandably keen to avoid discussing GV’s own technology roadmap, Meyer does pinpoint low latency video compression technology JPEG XS as one that he thinks “we will continue to see a lot of interest in across the industry”. More generally, “intelligent bandwidth management” will remain especially crucial for UHD production of major sports events, while he agrees with the suggestion that “UHD, HDR and WCG [wide colour gamut] will become more and more a default” for a wide variety of content.

Of course, the question on many people’s minds right now is whether the inevitably tough times facing broadcasters will impact upon the speed at which the HD to UHD transition is completed.

Fautier concurs with the suggestion that the pandemic may slow adoption, not least with regard to the postponement of many major sporting events that would have provided a showcase for higher-resolution, higher frame-rate content. But with the short-term future now promising an unprecedented density of global sports tournaments due to Covid-19 delays, “we should be poised for a couple of really strong years of increased production in UHD/HDR.”