8K and Beyond: How Much is Too Much?
Warner Bros.' stance is indicative of producers across the industry. "Virtually all our movies released in the home will be 4K with HDR and other attributes like Wide Color Gamut and Next Gen Audio," Michael Zink, VP, technology at Warner Bros. and chairman of the UHD Alliance, told an audience at IBC. "With this combination we can provide a premium experience. We looked at all of these attributes in isolation and concluded that just increasing the number of pixels or quadrupling them means that many times you can't tell the difference. But with HDR and other UHD elements, the consumer feels they are getting something extra."
Japan’s NHK is the only TV channel in the world that’s currently broadcasting 8K, and this summer, 62,000 people will be able to view the broadcaster’s 8K coverage of the Tokyo Olympics.
When it comes to production though, 8K is already proving its worth in a multiplicity of use cases. A growing number of productions are being acquired in resolutions of 4K and above. The additional resolution is useful for feature productions wanting to use anamorphic lenses with large format sensors, where the image needs to be squeezed to fit delivery aspect ratios. Similarly, the data overhead is widely used to retain high-quality final output for VFX-heavy shows. With workflow and compression schemes such as Redcode, the file format of the Red Digital Cameras that are widely used on premium productions, the cost of storing and transferring 8K-acquired footage is not significantly higher than for a 4K shoot.
Outside of high-end features and TV dramas, 8K documentary and reality programming is being commissioned by channels like Insight TV, principally for archive at this stage but with an eye on future sales and distribution.
Bluechip wildlife programming is another natural genre to benefit from ultra-resolution and future-proofed sales, although the demands of working with 8K data in the field are a drawback.
In live production, 8K is on track to becoming a regular part of broadcast techniques. Again, there are a number of applications, most of which stem from the economies to be gained from extracting multiple lower-resolution (4K/HD) images from a single 8K signal.
Panasonic's 8K ROI (Region of Interest) camera, for example, is able to produce four different HD signals or "virtual cameras." Each image can be panned, tilted, and zoomed individually. Up to eight of these units can be connected and operated, in theory, making a
32 x HD virtual camera set-up possible in one system.
German developer Cinegy has been promoting 8K for several years for multiviewer and playout solutions aimed at TV stations. It was able to take a lead on this by devising a proprietary codec called Daniel2, but its messaging is less about the use of 8K solo and more about the ability of the product to handle multiple streams of 4K.
Even as IP makes inroads into broadcast production for signal transport, SDI remains the familiar, trusted means of handling uncompressed pictures. 12G single cables make UHD transport possible without the complexity of a quad link, and, importantly, over distances of more than a few feet.
A number of vendors have released gear compatible with this method, including EVS, FOR-A, and Blackmagic Design, which has an 8K-capable live video switcher with 12G-SDI inputs and a converter to scale HD or 4K sources into 8K.
One of its switchers was used in an important IBC demo by U.K. pay TV operator BT Sport to transmit a rugby match in 8K from the U.K. to Amsterdam. The demo was not intended to announce parent company BT's launch of an 8K channel, but to underline the belief the broadcaster has in raising the production values of its sports coverage, while keeping costs down.
Mastering a live event in 8K yields better quality (better pixels) down the chain, even to SD/HD distribution of the same source pictures, BT argues, at the same time creating a one-size-fits-all production footprint. Early attempts to produce live 4K (and stereo 3D) relied on separate, costly outside broadcast chains.
"We're enhancing the capture of coverage to break it down to give to different people in different formats," BT Sport COO Jamie Hindhaugh explains. "This technology will enable us to offer something different from a creative storytelling point of view."
BT has also trialed ?K capture to feed 360° viewing on mobile phones, where the additional pixel overhead allows users to pinch and zoom into the "magic window" on their device.
This leads us to immersive media, 5G, and 8K, a perfect storm of technology likely to see commercial adoption as 5G networks and handsets roll out. Key proofs of concept here include the French Open tennis tournament last spring—where France Televisions and Orange, with the help of technical partners like Harmonic, demoed live streamed 8K images to HD/4K mobile devices—and Deutsche Telekom and MediaKind's basketball event on VR headsets.
Both approaches used a tiled encoding method where only the immediate field of view of the watcher is resolved. At IBC, MediaKind said it was looking to monetize VR 360° in
esports, gaming, music events, and football.
The largest VR 8K production to date will occur during the 2020 Olympics. Intel, NTT DOCOMO, and host broadcaster Olympic Broadcasting Services will produce live and
on-demand coverage in 360° 8K VR of track and field, boxing, beach volleyball, gymnastics, and the opening/closing ceremonies in an extension of trials at the Pyeongchang Winter Games. It's unlikely anyone outside of demo areas in Tokyo will view this in 8K, but the destination format is at any case downscaled 4K.
A Note on Codecs
For immersive media to fly, the industry is waiting on next-gen codecs.
MPEG's Versatile Video Coding (VVC) codec is due to be standardized this year to address 8K OTT. Rivals targeting the 8K space include an HEVC variant from Spin Digital. This runs on Advantech's encoder and delivers 8K HTTP Live Streaming (HLS) and Real-
Time Transport Protocol (RTP) streams with optional cloud support based on AWS to target wide-scale deployments of 8K live events. It's a joint development with Japan's NHK Technologies.
Meanwhile, China's state-owned Audio Video Coding (AVS) Standards Workgroup is designing the AVS3 codec for 8K and VR applications. It will be standardized by the IEEE. AVS patent pool holders include Chinese brands Huawei, TCL, and Skyworth.
"Now you have a new choice for 8K," said AVS Industrial Alliance spokesperson Sunny Niu at IBC 2019. "We have a better licensing policy—just one pool."
[This article first appeared in the January/February 2020 issue of Streaming Media magazine.]
With production challenge solved, smarter AI upscaling and enhanced codec technologies will enable 8K streaming to the home—inevitably.
Akamai Principal Architect Peter Chave discusses bandwidth demands attendant to the inevitable (however unnecessary) arrival of 8K streaming in this clip from his keynote at Content Delivery Summit 2019.
Ready or not, here comes 8K. Look for 8K sets to hit the market later this year, with TCL creating the first Roku model.
Though 4K is just becoming mainstream, cutting-edge technology pundits and some vendors are already pushing higher resolutions like 5K and even 8K. But it's far too early to be talking about resolutions beyond 4K for production and infrastructure, much less for consumer use.