Can we make Ultra HD Sustainable?
Posted on Jul 2, 2024 by FEED Staff
High-quality video is now no longer a bonus – it’s an expectation. But is our desire for a crystal-clear picture damaging our planet?
Words by Neal Romanek, editorial director, The Flint
The Ultra HD Forum was founded in 2015 amid a rush of anticipation around new, higher-resolution formats. Video in 4K is so much a part of every piece of the video workflow – everyone expects their phones to be able to shoot 4K video – that it’s hard to remember how, less than ten years ago, this was still cutting-edge stuff.
At the time, though, the only place someone could reliably find 4K video was on YouTube; the question of how to bring UHD into the mainstream was a challenge. There were many competing standards and the definition of UHD itself was up for debate. The Ultra HD Forum came together for the purpose of creating some order out of the chaos by pooling market leaders from around the industry, including broadcasters, service providers, consumer electronics and technology vendors, to collaborate on solving the challenges of Ultra HD development and deployment.
Among the Forum’s founding members were Comcast, Dolby, Harmonic and LG. The membership today includes many broadcast tech companies of note, as well as broadcasters such as PBS and the BBC and industry organisations like DTG, EBU and NAB.
“We didn’t set out to be a standards body,” says Ultra HD Forum’s Ben Schwarz, “because if anything, this industry suffers from too many standards, not too few.”
There were a number of standards available at the time, including UHDTV1 (with a resolution of 3840×2160) and UHDTV2 (a resolution of 7680×4320), and there was confusion about the difference between 4K and Ultra HD, with many assuming they were identical – a problem which continues among consumers to this day. Rather than getting into debates about which formats were preferable, the Ultra HD Forum provided concrete experience about what worked and what didn’t work.
“In the early days, we actually spent a lot of time asking ‘what is UHD?’” says Schwarz. “It seems really obvious today, but back then it wasn’t.”
Getting the language right – not to mention getting everyone to agree on it – is essential for making progress in tech. The Forum eventually decided that the acronym UHD would essentially be a synonym for 4K, and the full expression Ultra HD would refer to the whole range of next-generation entertainment services defined not only by increased resolution, but high dynamic range (HDR), wide colour gamut, next-generation audio and high frame rate.
“If you have a 4K service, we’ll call that an Ultra HD service. But if you have an HDR service, even if it’s not 4K, we’ll call that an Ultra HD service too.”
Sustainability is always about people and how best to serve their needs in the long term. The Ultra HD Forum’s aim is to enable a higher-quality experience for audiences, as well as a more comprehensive palette for storytellers. Sustainability is about quality, and quality is where intelligent engineering combines with customer care. The Ultra HD Forum wouldn’t think of itself as a sustainability organisation, but joining the practical with the needs of customers is where sustainability can really get traction.
Most viewers assume that improved technology will give them a more realistic experience, but of course, there is no such thing as a realistic viewing experience – aesthetic decisions are made even on the most basic YouTube video. Secondly, they assume that they prefer a more realistic experience over a less realistic one.
Ultra HD Forum’s Schwarz explains that this is just not the case: “People say the more realistic the better, but a few years ago, we did a golf broadcast demo at NAB we were incredibly proud of. We had a 4K version and it was like looking out a window. You could really see the grass and the earth.
“Next to it we had another squashed-down version of it which looked like the traditional unreal grass colour you would see in the cinema – bright green. Almost everyone preferred the bright green grass; that had nothing to do with reality, it’s just what they were used to.”
Sports broadcasters still routinely adjust camera settings so that sports fields register as bright green, even though if you saw that colour in real life, you might assume your drink had been spiked.
“It was a surprise to realise that we thought Ultra HD would be fantastic because of the extra realism. It’s still a powerful tool for sportscasters because it gives them more and deeper colours to work, but they are still trying to reproduce what they’ve been doing for the last few decades.”
The Ultra HD palette of tools can be extremely powerful for broadcasters – and for audiences – but creators need to be holding the audience in mind as the priority. Give sports fans realistic grass before they’re ready and they’re likely to start complaining about some very, very lucrative content – and no one wants to be on the end of that phone call. Give them a beautiful piece of art that only works if viewed in perfect HDR conditions and you get The Long Night episode of Game of Thrones.
Who’s got the power?
One of the central sustainability issues for Ultra HD content – in all its iterations – is the increase in energy consumption it brings. HDR monitors consume substantially more energy than standard dynamic range monitors for example, and the files required for a 4K workflow and delivery consume more energy at every step along the chain than the same workflow would in HD – and this has become more or less the default. 4K capture is generally the standard, even if everyone involved knows the final result will never show at anything higher than HD.
High frame rates, which are part of the whole Ultra HD package, also mean a lot more data storage requirements and throughput. A 4K image is four times as big as an HD image, and if you ramp up a 30fps show to 60fps – or 120fps, which is what the Ultra HD Forum considers a genuine high frame rate – its footprint expands over traditional HD at a jaw-dropping rate.
Most new TV sales today will be 4K HDR TVs, but most of those won’t even display much native 4K or HDR content. Built into the system of living room entertainment is an increase in the power consumption, which is standing ready for content that’s only played occasionally.
Additionally, other devices that work within the ecosystem might not always have power consumption and efficiency in mind. The Ultra HD Forum strives to create links between suppliers and service providers to create interoperability and consistency. Sustainability is impossible if every contributor to the supply chain is operating alone.
One example that points out the waste which can occur is TV device manufacturers deciding that, if their TV is attached to a set-top box with HDR support, then the TV will output an HDR image. But this can lead to absurdities like SDR signals being converted to HDR in order to be played out by the TV as SDR images. Encoding and decoding always costs a lot of energy. The less decoding that happens throughout the process, the better.
Deciding where decoding happens requires intelligent engineering, but also communication among vendors and operators. Decoding in hardware is more efficient than doing it in software, but it’s not always possible. A lot of our sustainability issues get pushed on the cloud, but decoding in software uses a lot of CPU power.
Though the Forum doesn’t only think in terms of sustainability, helping its members create greater efficiency has always been part of its mission.
Ian Nock, media tech consultant and the chair of the Ultra HD Forum Interoperability Working Group, explains: “What comes before energy usage for many is the fact that it costs money. When people first started producing 4K HDR content, there was this issue about it requiring a lot of coding and a lot of bandwidth, and we asked how we could improve that. It just so happens that cost is a synonym for energy usage in many streaming environments.
“We’re a good engineering organisation and that’s really what comes through. Sustainability is just an engineering aspect you need to deal with.”
The Forum and its members are experimenting with a number of new strategies for reducing power consumption in Ultra HD images. French research company Interdigital, also an Ultra HD Forum member, is working on projects aiming to lower the power consumption in HDR displays.
The first, Advanced HDR by Technicolor – a collaboration between Interdigital, Philips and Technicolor – is a suite of high dynamic range production, distribution and display solutions that leverage machine learning to maximise the image quality of any HDR format. The technology adapts the rendering of the HDR content to the display’s capabilities. It can offer the opportunity to lower the energy consumption of the display, by reducing peak luminance for example, but still preserve the quality of the image.
“It’s not just cutting back on the image and getting rid of the brightest area,” explains Valérie Allié, Interdigital Video Solution Group senior director. “It really is about adapting the content so that the viewing experience and the creative intent are the same but with lower energy consumption.”
The other technology Interdigital is working on, which is still under development, is Pixel Value Reduction (PVR), which uses AI-based technology to adapt the image at the pixel level. Where Advanced HDR works at the image level, PVR can work at the level of individual pixels to reduce energy consumption, which also gives even greater control in retaining the quality of the image and user experience.
What’s next?
In 2018, the Ultra HD Forum created a Service Tracker to monitor consumer-facing UHD services in the real world. When it was launched, there were so few services that they could be counted on one hand. Now there are 248 Ultra HD services being tracked. The tracker provides invaluable data about each channel, its technical parameters, including codecs used, and what Ultra HD services the channel provides.
The historical data is particularly powerful, allowing researchers and technologists to see the waves of different codecs, audio technologies and other tech waves and how they were implemented around the world.
The kit of tools under the Ultra HD banner (HFR, HDR, 4K etc) are becoming widely available now, and the Ultra HD Forum aims to turn its view on prosumer and even consumer use.
“At least 50% of phones people carry in their pocket can do HDR and a large number of them can shoot 4K – some can shoot 8K,” says Schwarz. “We’re confronted with this new world. We feel that the Ultra HD Forum has a role to play there.”
“There may come a day where we won’t refer to it as Ultra HD technologies,” adds Nock. “They will just be video technologies – high dynamic range, wide colour gamut at any resolution you want and higher frame rates, all delivered to consumers with next-generation audio on top of everything else. The fact that it can be done in someone’s home with equipment they’ve got around them is a game changer.”
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This feature was first published in the Summer 2024 issue of FEED.
