UHDTV: Building The Plane In Flight

Chaired by Pete Putnam of ROAM Consulting, a group of three panels focused on "UHDTV: Building the Plane in Flight." The first paper, on the development of Super Hi-Vision (8K) was presented by NHK Broadcasting's Kenichiro Ichikawa. He showed 8K  content production using the Sony F65, shooting cultural artifacts at a national museum, and doing live location shooting at the 2014 FIFA World Cup. NHK is now devloping Super Hi-Vision system and equipment; currently little equipment is available for 8K content production. But the demand for high-quality programming is growing, he said, and 4K equipment is becoming standard in the movie industry. "F65 has a horizontal sampling pattern that is equivalent to 8K resolution," he added. "We developed a baseband processor unit, BPU-8000 for converting output from the F65 into an 8K signal."

The BPU-8000 takes F65 RAW as input with output at 8K (59.94P, dual screen, HD-SDIx16) or 4K (59.94P/I, Y/Pb/Pr, 4:2:2). A chart showed the flow of internal signal processes as the F65 RAW data and 4K signal are converted to 8K, 4K and HD signal at the same time, and in real-time. A super-resolution technology is used to generate the 8K signal.The generated 8K signal (4:4:4) is down-converted into Dual Green 8K. The input picture is broken down into video patterns, and the patterns are used as references to look up optimal patterns in the database; the optimal patterns are used to restore the picture. Super-resolution technology suppresses the noise. One image showed a comparison of the shooting image processed via demosaicing (aka anti-aliasing) + super-resolution and the BPU-8000. The former showed issues of noise and color reproduction. In the BPU-8000 image, there is no zipper noise. With regard to color reproducibility, the former image is washed out, whereas the BPU-8000 processed image generates a more true color. He described the evaluation method, which included static characteristics of the F65, resolution characteristics and color reproducibility. The results showed static video characteristics and video processing latency. Results of resolution characteristics showed that the responses of the F65 are quite high regardless of 4K lens. In conclusion, the BPU-8000 was developed for 8K content production; its function has been evaluated and confirmed to be effective for 8K content production.

Stephen Lampen, Belden Multimedia Technology Manager/Product Line Manager for Entertainment Products presented on "Further Developments in 4K (12 GHz) Single-Link Coaxial Cable," which outlined the hurdles that 4K signals present and some of the existing solutions, such as dual-link or quad-link cables. "These 4K signals represent many times the bandwidth of existing HD or even 3G video," he said. "There is professional and commercial 4K. Commercial 4K is unsampled and often uses HDMI or Cat 53/6/6a. Broadcast 4K allows the user to zoom into a quarter of the picture and still have full HD video, and that's something that's already happening." He also distinguished between "Hollywood" 4K (4096x2160) and Broadcast 4K (UHD, at 3840x2160).

"My real question -if you're convinced that 4K will work on coax, how many people will put in coax for 4K?" he queried.  Nobody raised their hands. "Everyone is assuming you have to go fiber," he said. "You're going to have too many choices going down the path." Disclaimer: there are no standards for 4K single-link cable ("lots of talk, nothing signed"). "By the time you get to 18 GHz," he said, "Nobody does test equipment for that. Belden was the first to say we'd test to 4.5GHz for 2K, and built customized equipment to do so and up to 12 GHz." But 18 GHz won't happen for four years, say the manufacturers. "It's the technology inside the cable that makes the difference," he said. "It's not what you see but how it performs. RIght now, all I can do is test to 12 GHz. I guess that won't matter since you're not going to buy coax!"

Multi-coax isn't a problem, the problem is single-coax, he emphasized. As the chips improve, so does the distance," said Lampen. He thanked Hugo Gaggioni and Merrill Weis who came up with the formula for -20 dB @ 1/2 clock - but that's the old formula. "On the way there is 6 GHz," he said. "And you can go pretty far. Is it full bore 4K? I'm not a chip guy. What you really want to talk about is 12 GHz. That's the problem. The numbers aren't huge, even though there's a new formula -- -40 dB @1/2 clock. Is it far enough? If it isn't, we're not going to make any."

"But," he said, "If you leave the coax realm and head into unknown, new territory filled with problems you've never dealt with." How long do you need? RG-11, the largest we made, will go 347 feet. "We go up to .50" (14.99mm) in a 50-ohm coax, and it's probably still cheaper than fiber by the time you add in the conversions at the end." Also required will be shielding for 4K. "We'll take the first foil and glue it to the core," said Lampen. "It gives a faster and more accurate connectorization and improves return loss." He listed a number of 4K choices including riser-rated CMR, plenum-rated CMP, unrated flexible, low smoke, zero halogen (Europe) and water-blocked, super-rugged. "The flexible stuff is twice as expensive with half the performance," he noted. He went over the pros and cons over the other choices, and said that cable should (hopefully) be available Q1 2015.

The last presentation of the day, by Archimedia Technology co-founder Josef Marc, looked at "Viewing 4K and UHD in an HD World." "HD infrastructure will not, and should not, convert to UHD/4K/8K overnight," he said. "The next few years will be experimental and educational. People will need to see, hear, and understand UHD/4K/8K video on HD screens, and HD video on UHD/4K/8K screens." He showed images from his "1 1/2 years of real-world experience in production, post-production, mastering, quality control, and exhibition" and the "Rubik's cube between cable and display." "Hint: frame sizes are easy, whereas colors and edges are harder," he said. Archimedia developed a test pattern for Netflix. Why was another test pattern needed?

There are a range of high-level categories of viewing experiences in the field today. SDI 4:4:4 is the simple one, "the one we know and love," but there are potential truncations from UHD 12 or 16-bit color to 8/10/12 bits. SDI 4:2:2 is common for HD 1920x1080, and there are potential conversions from UHD RGB color to YCbCr.   SDI Quad Link works great, he said, and showed an image with various paths to doing this. "Over 4 million UHD TVs have shipped with HDMI and some with DisplayPort," he said. "The card driving this can be near the display, but it's a graphics card so..." 

"When you're trying to watch UHDTV on HD, disable the enhancements that are naturally built into the TV," he said. "I can disable all that communication at home. That's a new area that you, as engineers, need to think about. What should the test pattern look like?" He noted that 32-channel audio supports experimenting with new apps and chipsets supporting multichannel audio formats from Dolby, NHK, THX, DTS and MPEG. Dolby Atmos is in home receivers now and TV speakers include down-mixing chipsets. "It's going to work," he said. "How do we tell people what they're listening to you and how do you as engineers show them?"

"That computer monitor we love can be extended to a real TV," he said. "You've got DVI left over, that's what it's good for." Scaling can happen in a card, a display and a professional media player, he said. "When's the last time you looked at your scaler?" he asked. One person raised his hand. "You can get software scalers and media professional should use them," he said. "You should have waveform monitors on your desktop to measure the file. We have found some users who have SDI monitors, the best possible UHD TVs and desktop monitors in the same room. These things can look really good with the proper engineering and the right scale."

The conclusion is that HD remains a good personal viewing size, even for 4K and UHD. Display links are the keys, and 4K sources make better HD. "Engineers learn and explain while we build the UHDTV plane in flight," he said.