Television, and the TV industry, has changed a lot in recent years. We watch an increasing amount of content on smaller screens, such as mobiles, tablets and laptops, including over one billion hours per day on YouTube – mostly created by non-traditional producers. In a world with more small screen, more personalised viewing, how does the big screen in the living room compete? On quality.
It needs to up its game, present sharper, more beautiful pictures in a larger format and with great sound. Much like cinema has competed with television, by creating more of a spectacle. This is where UHD fits in; the premium experience. And with a lot at stake across the industry on its success, it has made steady progress over the past couple of years.
The initial focus on increased spatial resolution, 4K, has been augmented by HFR, HDR, WCG and NGA. Standardisation has followed suit, with the DVB’s UHD-1 Phase 1 specification being extended to include HFR, HDR and NGA in the recently published UHD-1 Phase 2 version. The UHD Alliance produced the UltraHD Premium brand to help consumers buy new TV sets with confidence and without having to rattle off the many acronyms of UHD to a sales assistant in their local retailer.
But the TV itself is only the tip of the iceberg in bringing UHD content into the sort of mainstream position that HD holds today. Everything from the cameras, distribution links, production tools, codecs, storage systems, graphics systems and the creative and engineering skills that go with them are having to evolve to feed those screens with worthy content.
The challenges are various. With 4K it’s largely about sheer size – bitrates range up to 12Gbps in its baseband form, such as that used in a broadcast facility, down to about 25Mbps for an individual compressed stream to a consumer device. That’s a great deal of bandwidth to deal with as a stream or to store as a file.
Across the industry, facilities have had to be upgraded, capacity increased. This comes at a crucial time, when the migration from SDI to IP is still a work in progress and difficult decisions need to be made as to whether to push forward with high bitrate IP links or be conservative and use quad 3G-SDI infrastructure.
In the file domain, choices also need to be made with regards to codecs and bitrates. UHD material can range from 150Mbps to 500Mbps – large files, with all the storage, processing and data transfer overheads associated.
But 4K is just one aspect of UHD and many believe that HDR, in particular, brings greater visual impact. The increased range between dark and light provides a new palate to work with. Combined with the wider colour gamut of UHD, standardised in BT.2020, this is less of an infrastructure challenge than a creative one. How can artists best exploit this format to deliver a richer experience to the audience?
This requires new craft skills, from set lighting to colour grading in post-production.
From a technical perspective, there are considerations in the compression process to maintain artistic intent. Rendering on the display device requires additional information to be presented and multiple techniques are available such as PQ and HLG. This presents compatibility challenges to the CE manufacturers who must be able to accommodate the different approaches and standards based or vendor specific implementations. It also creates additional complexity to broadcasters who need to incorporate these new formats alongside their existing HD and SD outputs.
However, if we put these behind-the-scenes questions to one side – does the viewer care about the quality and presentation of their content? Consumer research suggests that we like better pictures – it drove the migration to HD and seems likely to do the same for UHD. That is why the new entrants, such as Netflix and Amazon, are commissioning all new material as UHD native. The transition from SD to HD is likely to be longer than that from HD to UHD. The cost premium of UHD TVs is dropping fast, with UltraHD Premium sets now available in the UK for less than £1000, 4K models for much less, and those buyers will be looking for UHD material where it is available, putting pressure on content producers and broadcasters to respond.
It is over 10 years since Sky launched their HD services in the UK. During that time, HD has become the standard rather than the premium product. It is not unreasonable to assume the same transition for UHD. There are other, more recent, considerations too. VR places our screens millimetres rather than metres from our retinas. HD looks rather poor at that distance, just as SD does now on our 60 inch TVs. If that format is successful, then 4K is a basic requirement.
There are still a number of technical, creative and financial hurdles to overcome to make UHD the next standard definition, but we seem to be making reasonable progress to achieve that goal.