Home >> November 2008 Edition >> INSIGHT - Super HD: Technology Jump?
INSIGHT - Super HD: Technology Jump?
by Chris Forrester

Super HDTV, NHK’s 8K format ‘next generation’ broadcast technology, was displayed in all of its visual and audio glory at IBC. In the view of most of the observers, Super HDTV represents the ‘next step’ for higher definition (HD). NHK’s demonstration theatre will almost certainly be present at NAB in April of 2009, so be certain to take a peek at the technology — I think you’ll be impressed.

In the words of many industry professionals who witnessed the NHK demo at IBC, it isn’t so much that the images are stunning (they are!), and the audio phenomenal (which it is!), but in the manner in which the technology has progressed and matured over the past two years. The other dramatic change over that timeframe is that the actual ‘delivery date’ has shortened. A couple of years ago, NHK was stating 2025 for the mass-market — that’s now 2018 or 2020.

That’s quite a considerable difference. With detailed trials and tests likely to start in Japan in about 4 years time, the prospects of a 2016 Olympics (perhaps in Chicago) being transmitted to Japan on Super Hi-Vision is now a distinct possibility. Moreover, the world’s satellite operators must be rubbing their hands with glee at the thought of all this extra contribution as well as DTH transmission being in Super HD.

“It is the next big technology jump,” said Hans Hoffmann, the European Broadcasting Union’s (EBU) senior engineer. “Broadcasters around the world are now migrating to HDTV. We know HD has two standards — 720p or 1080i. The next step is 1080p at 50 or 60 Hz. Then the industry has to look at the next big technology jump. Investment is all-important, while we must also remember that there are other interested parties, like the gaming sector, interested in what we are doing, or the role broadband and a home storage device might play.”

Peter Symes, the Society of Motion Picture and Television Engineers (SMPTE) director of standards and engineering, agreed that Super HDTV is a very forward-looking development from NHK. “In some ways, we are at the same point today that high-definition was in during the late 1970’s. We are already at the same position HD was in the mid-1980’s. The main point here is that people are now looking at developing applications based on standards.”

Asked whether a ‘World Standard’ for Super HD might now emerge, Symes replied “It could, but don’t ask me if it will!” He added that NHK’s demonstration showed what was possible with today’s technology. “However, 140 Mb/s for distribution to the home is not practical.”

Hoffman said the EBU welcomed the fact that Super HD was a Progressive standard. “However, for the moment, it concentrates only on spatial enhancements. We might also see the enhancement of temporal resolution, for example, and this might result in us taking the frame rate up to 100 or 200 or even 300 fps, not at 8k but using 4k in order to keep bandwidth manageable.”

Super HD – But When?
There’s been remarkable progress on the NHK Super HD project over the past two years. While the cameras are still best described as ‘advanced prototypes’ they now have everyday flexibility in terms of zoom and focus. This, together with the progress being made in projector technology as well as flat-panel developments has given NHK the confidence to significantly reduce their anticipated service date introduction. Two years ago NHK were predicting a introduction date 2025 date (and coincidentally the 100th anniversary birthday for NHK).

“Today,” says NHK’s R&D chief Dr. Keiichi Kubota, “a 2025 introduction is too long. In my view 10 years is enough. It is our responsibility to show broadcasters and network operators that Super High Vision is not just a dream but a real future television system.” Kubota said the system was best viewed on large flat-panels of at least 70 to 100-inches and these would start appearing in the next 2-3 years, and then at increasingly affordable prices.

NHK’s team leader Dr. Kubota highlighted two big differences since Super H-Vision wowed visitors to IBC 06. First was the optical fiber and satellite transmissions from London and Turin (handled by Cable & Wireless and Eutelsat, respectively).

Second was the concerted R&D support of the BBC, RAI and the EBU. More partners are being sought. It is no coincidence that, a few months ago, a senior engineer from NAB was in Tokyo talking to NHK.
“NHK’s goal is for Super Hi-Vision to be enjoyed in every home,” said Kubota. “ It is our responsibility to show broadcasters and network operators that it is not just a dream but a real future television system.” Kubota believes public attended applications will be possible before a full production system is possible around 2020.

Examples were given of museums and galleries where ‘transmission’ wasn’t a problem. Same with city centre venues for high-quality concerts, ceremonial occasions, and the like.

Speaking for the BBC, Dr. John Zubrzycki, principal research engineer, BBC Research & Innovation, said: “We started our practical work at the beginning of 2007 with Dirac coding. I think Dr Kubota is probably right about the 12-year program, because although the transmission demo shows NHK has come a long way we still have prototype cameras and projector systems,” he added. “And of course, the big thing to wait for is full 8K resolution of domestic displays.”

[Editor’s note: Dirac coding is a prototype algorithm for the encoding and decoding of raw video.]

The prototype cameras used for the demo used offset 4K sensors to record the 8K images. NHK has now developed a full 8K sensor with 33 mega pixels. The compression used for the satellite transmission from RAI in Turin (16 parallel H264 encoders) took the obvious toll on the projected image, which Zubrzycki acknowledged.

“There are still a lot of improvements to be completed with video coding, and that’s really the core of our research with NHK. We need to improve on the quality and reduce the bit rate further to make it more efficient for satellite broadcasting,” he said. “The next step we’d like to see is the BBC’s Dirac hardware and move away from software coding. There will be further developments towards making contribution links more practical for doing outside events,” he added.

Andy Bower, the BBC’s head of Broadcast Research & Innovation, speaking at IBC, said the world would embrace next-generation HDTV. “Audiences demand and expect increasing levels of picture quality and user experience,” he said. “Past developments, from John Logie Baird’s 30-line television system in the 1930’s, right up to today with the launch of digital HD services in many countries over the past year, have been the “high-definition” systems of their time.”

He explained history reveals that as technology advances, affordable receivers become available to meet audience’s demands for quality and user-experience. “The acquisition of large flat-panel displays is growing quickly across the world. They are getting larger and thinner, with increasingly better picture quality. Consumers will get higher resolution content from recordable media, such as Blu-ray. Higher resolutions will become available for gaming and computer applications. Digital Cinema and 3D in digital cinemas is growing — consumers will eventually expect this content and experience in their own homes. So broadcasting must keep up, or even set the pace!”

Bower also believes the next level of HDTV will not require 25 years to occur. “While it probably will not take that length of time for the next generation of systems, we need to research the foundations for ‘Beyond HDTV’ now. However, it is too early to know exactly which system or systems will eventually succeed our current HD services.”

He described NHK Japan’s Super HD development as a “prime candidate” for further work, and was a great start. “With greater spatial resolution, higher frame rates of several hundred frames per second or more are likely to be needed to preserve picture detail on moving objects, or when the scene pans. Fundamental studies are underway within a number of research laboratories to investigate this.”

“To date, development of Super HD has very much focused on increasing spatial resolution, interest in the use of higher frame rates to improve dynamic resolution on moving objects or for panning, is now growing. It is likely that frame rates well beyond the current 60 Hz, and of the order of 240 Hz, are needed as you quadruple linear resolution of current HD, said Bower.”

Besides the NHK efforts, there was some considerable heavy lifting done by some other consortium members. Siemens (the old BBC Technology arm) handled this experimental format of the future, which is 16 times the resolution of ‘ordinary’ HD. Project management for the London demonstration was in the hands of Siemens IT Solutions and Services, who designed, tested, and implemented the IT and broadcasting infrastructure.

Part of the overall circuitry came from Eutelsat, which supplied a pair of satellite transponders for the exercise. This portion of the scheme was handled by SIS Live (formerly BBC Outside Broadcast). Italy’s RAI public broadcaster was also involved. At RAI’s research centre in Turin, the content was played out into the IBC demonstrations and was compressed using 16 MPEG-4 encoders to a bitrate of 140 Mb/s. Eutelsat is providing two full transponders on Atlantic Bird-3 to carry the signal to Amsterdam.

The live feeds were broadcast via the Siemens London Media Gateway and 1Gbit/s international links from partner Cable & Wireless. Siemens and Cable & Wireless say they worked together to supply a resilient circuit architecture that would provide error free and minimal IP packet jitter and loss for the transmission. Then, Siemens subjected the circuits to testing, using the standard IP network testers as well as techniques developed with WAN and LAN tests for the transmission of streamed broadcast content.

About the author
London-based Chris Forrester is a well-known entertainment and broadcasting journalist. He reports on all aspects of the TV industry with special emphasis on content, the business of film, television and emerging technologies. This includes interactive multi-media and the growing importance of web-streamed and digitized content over all delivery platforms including cable, satellite and digital terrestrial TV as well as cellular and 3G mobile. Chris has been investigating, researching and reporting on the so-called ‘broadband explosion’ for 25 years.