DTG: What is Ultra High Definition TV and is this the big year?12 September 2014
4K and UHD have been buzz words for the last three years at IBC, each time suggesting that this might be the year. The year meaning the technology is getting ready to be rolled out to a consumer accessible platform. With that in mind, where are we today – and are we now at least agreed on a definition of what we mean by UHD?
CE manufacturers are making and selling 4K TVs. These all have 3840×2160 pixels of resolution, almost all run at up to 60 frames per second and include at least one HDMI 2.0 input. Some 2014 models now support the 4K Netflix application so customers can see more than just home photos in high resolution.
This also means that HEVC (H.265) decoding capability is built into the TV but usually only for sources via IP or a USB plugged directly into the set. In June of this year, the Consumer Electronics Association (CEA) updated its requirements for the Ultra-High Definition logo which is currently planned for this year. The update added IP delivered HEVC requirements within a TV set, along with HDCP 2.2 support for content management, but kept the minimum requirement of 8-bit.
Although publically available if you know where to look, 4K content is limited to a couple of seasons of Netflix dramas and user-generated YouTube content. 2014 has, however, seen a massive increase in the number of broadcast trials being undertaken which should theoretically lead to consumable 4k services.
Sky Deutschland has continued its live sporting trials, edging closer to a complete live end-to-end production chain. The World Cup provided some of the best 4K coverage of a live event to date, and the BBC used the Commonwealth Games to demonstrate a complete IP studio infrastructure of 4K content. Delivery of 4K services has now been seen over satellite, terrestrial, cable and IP using Dynamic Adaptive Streaming (DASH).
Even the standards to deliver this 4K content, the DVB titled ‘UHD-1 Phase 1’ have been agreed and published. So if the broadcasters can make it and the TVs can show it, surely we are just a breath away from the birth of UHD services?
Innovation on a stable platform
However, questions still remain unanswered. Does the move to 4K resolution and progressive 50/60 Hz give a big enough step-change in picture quality over full HD? More importantly, can a business model be found to ensure additional revenue can be made to fund the cost of this new service?
The ITU standard for UHD, ITU-R Rec 2020, includes more than just resolution. It includes higher frame rates (up to 120Hz), higher bit-depth (10 and 12 bit) and wider colour representation. In the absence of any displays to demonstrate this wider colour yet, work has focused on ensuring that the metadata can support the delivery of this information in order to cater for a possible future solution.
The BBC and NHK have done lots of experiments to demonstrate the benefits of higher frame rates. At the Commonwealth Games, the BBC captured some test footage of 4K at 400 Hz which was then converted to HD at 50Hz and 100Hz to display and compare the difference.
Engineers are looking at the higher bit-depths to deliver improvement to the dynamic range problems. There are many scenarios where the limits of current TV systems lead to burned-out or crushed images, the classic being a football stadium in part shadow. Cameras are capable of capturing a much greater range of information so lots of work is ongoing to find a High Dynamic Range system to deliver this improvement through the chain. A recent DVB/EBU workshop looked at four potential solutions to this problem.
Meanwhile in Japan, NHK is still driving towards an 8K system, Super High Vision, and planning to start trial broadcasts in 2016 with a mind to present full services in 2018. This not only enhances the image, it also delivers 22.2 channels of immersive audio. After successful trials at the London 2012 Olympics, further tests were captured during this year’s World Cup.
Could it be however that this push towards an 8K service might be somewhat premature? Not all television viewers have adopted full HD (only 75% of US homes watch HDTV) and it still seems that 4k services are only just on the horizon. We need to ensure that all services that are launched adhere to specification requirements for broadcasters, manufacturers, infrastructure providers and platform service operators to ensure the end product is as complete and foolproof as possible.
How do we ensure that the industry delivers something as clear and ubiquitous as HD for the next generation of TV?
In short, we need to get everyone to collaborate and agree a stable common foundation on top of which organisations can innovate. This is something the DTG has done with great success in the past and continues to do with UHD.
The DTG’s UK UHD Forum brings together the entire ecosystem; studios, broadcasters, platforms, TV manufacturers, silicon vendors, camera manufacturers, retailers and other infrastructure providers to create a forum of stakeholders in a 4K proposition and ensure they are fully engaged and informed. To ensure we don’t isolate this to the UK, this Forum is represented at FAME (Forum for Advanced Media in Europe) and maintains an open dialogue with standards bodies and similar international bodies. If you’re interested in getting involved, please contact SGauntlett@dtg.org.uk.