8K: History Repeats Itself
There's such an inevitability about 8K UHD content going mainstream that discussions about it are now are invariably sanguine about 12K, 16K, and beyond.
"8K is beginning to take hold," Nick Ryan, head of product marketing for MainConcept, said on a MainConcept-hosted webinar. "It can be easy to get overly focussed on the technical hurdles but we need to remember that long ago the idea of 4K was scary. Now the industry has accepted it as a gamechanger. I have no doubt we will be having the same concerns about 16K and looking back at 8K as a gamechanger."
8K production is just about cracked, and the distribution challenge is also being solved thanks to new compression and processing techniques.
Chris Chinnock, executive director of the 8K Association, ticked off the expanding 8K ecosystem. These include flagship 8K TVs from all the major brands and next-gen games consoles supporting 8K playback (even if there may not be many 8K games initially). YouTube and Vimeo host thousands of 8K clips, mostly short form or wildlife, which is seeding 8K the same way 4K did. Production workflows for 8K are understood to be similar to 2K and 4K.
"There are some pain points," Chinnock said. "You need more processing power, memory, and storage, and transport will always be an issue. But guess what? Those were the exact same issues as we experienced with 4K. The bottom line is that the 8K ecosystem looks similar to how 4K did seven years ago. We'll see history repeating for 8K."
Japan's NHK has been broadcasting 8K since December 2018, encoding in HEVC at 80Mbps to 100Mbps and using up an entire satellite transponder.
"They have proven it can be done but it's not commercially viable," Chinnock said. "We will have to move to bandwidths that are more mainstream. 20Mbps to 30Mbps up to 50Mbps is reasonable for deployment."
Fortunately, this is achievable thanks to new codecs including HEVC, VVC, EVC, LCEVC and AVS3 from China, as well as "smart streaming."
Chinnock explained, "Smart streaming is intended to encourage content to be mastered in 8K and then smartly downscaled to a 4K resolution package with some sort of metadata, distributed in 4K, and smartly upscaled to 8K on reception. Ideally the image quality will be close to native full 8K. That is what the 8K Association would like to see implemented. There are positive developments, but it needs nurturing."
MainConcept singled out LCEVC as the most interesting crop of current codecs. The standard, which is shortly to be ratified by MPEG, is compatible with other main baseline codecs and can immediately offer bandwidth savings.
V-Nova, the UK-based developer of the technology behind LCEVC, is a partner with MainConcept. Ryan shared preliminary test data from V-Nova demonstrating how an 8K file encoded in LCEVC-enhanced HEVC/H.265 delivered bitrate reductions of 45% giving a VMAF score of 90.
"For the VMAF score of 95, there was still very significant bitrate reduction," Ryan said. "This just one 8K test but we see this as very promising data. We will continue to work to integrate LCEVC into the MainConcept SDK."
He argued that HEVC/H.265 is most suitable for 8K today because of the billion devices enabled for HEVC playback in the market.
MainConcept claims its own HEVC software encoding algorithm is 20% more efficient compared to its open source equivalent. "When you think of the large data for 8K, any saving in file size has a very large impact," Ryan said. The software also allows for 8K live streaming at 120 fps 4:2:2 10 bit for digital signage as well as broadcast application.
MainConcept also flagged what it called hybrid GPU acceleration as a way to further boost 8K streaming efficiency. "This allows you to dial in the best of both software and hardware encoding to accelerate the overall process by up to 2.5x," Ryan said. "For 8K, this will save time and also makes things like archival and live encoding realistic and much more cost-effective."
To back that up, MainConcept claimed that the cost of setting up 8K live encoding using its hybrid GPU technology and a basic hardware mix of Intel processors, Nvidia GPUs, and AJA capture card will set you back $8,000 off-the-shelf. Without using the hybrid GPU and instead running multiple CPUs and high-end Xeon Platinum processors the cost is more than double, it said.
"The takeaway I have is that it is unsafe for studios, content suppliers and the tech suppliers that support them to build their workflow and tech stack based on current technology levels," Ryan said. "Really you need the flexibility to scale for the future without having to overhaul your production pipeline."
Speaking for Samsung, Des Carey, the firm's head of cinematic innovation, said capturing in 8K was the best way studios now had of futureproofing their content.
"For the longest time, film was the gold standard when it came to archival. Now for the first time we are able to capture at a resolution that is considerably higher than 35mm (he put 35mm at 5.6K). In saying that, embracing change can be difficult."
"Historically speaking the biggest changes in our industry have come from indie filmmakers who drive innovation to crate content. More indie filmmakers today are shooting at higher resolutions than studio projects."
He added, "Remastering a film from 35mm is time consuming, costly and can add artefacts and scratches. With 8K data it is easier to get back to what you initially shot.
"With 8K data we have option to conform at 2K, 4K or 8K and as AI upscaling becomes more robust we will see Hollywood blockbusters shooting at higher resolutions."
An example is Jurassic World: Dominion, currently shooting on 35mm and in 8K on Panavision cameras.
"In 2020, 90% of the large VFX shows are working in 2K even if the final output is 4K DCP. At Samsung, when it comes to displays, we are focused on the AI upscaling aspect. We want to work with the VFX vendors so that processing becomes more robust VFX will be able to turnover at higher rez.
"We want to work with video game developers so they no longer have to trade resolution for framerate. We are trying to find ways of keeping both of those aspirations intact."
BT Sport delivers first live 8K broadcast of a top-tier sporting event into the home, a broadcast of the Saracens v Bristol Bears Gallagher Premiership Rugby Match on March 26.
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