I have a confession. My colleagues in the broadcast industry would probably call this blasphemy, but when, as a fresh-faced school girl, I first saw high-definition television (HDTV), I didn’t really see what all the fuss was about. I had never particularly noticed the inadequacy of standard-definition (SDTV), probably because I was engrossed in the content and not too bothered about the quality.
Now I view it with technical eyes, of course I can see the benefit. However, it does mean that when NHK (the Japanese public broadcasting organisation) announced Super Hi-Vision (SHV), I couldn’t help feeling a little sceptical about whether the improvement would be dramatic enough to make the public take notice.
Intrigued by the technology, I volunteered to work on the Super Hi-Vision Olympic screenings run by BBC R&D in conjunction with NHK. So that’s how I came to spend my summer immersed in all things Super Hi-Vision at the National Media Museum in Bradford, one of the three UK venues (the others being in London and Glasgow) trialling the technology.
So the question is, does it live up to the hype?
Strictly, the technology is termed Ultra High Definition (UHDTV); Super Hi-Vision is the name of NHK’s implementation of it.
To put it in perspective, SDTV is 720×576, which gives 414720 pixels in total. The most common version of HDTV is 1920×1080 giving a total of 2073600 pixels, five times that of SDTV. Super Hi-Vision is 7680×4320, a total of 33177600 pixels, sixteen times that of HDTV and a huge eighty times that of SDTV. The image below depicts this:
The current technology has a progressive frame rate of 59.94Hz, limited by cost and huge data rates. The UHDTV specification has recently added a frame rate of 120 Hz progressive, which future versions of SHV will implement.
The other major aspect of UHDTV is the audio component. This comprises 22 full bandwidth channels and 2 low-frequency effects channels – giving it the name 22.2 surround sound. The speakers are arranged in a three dimensional cube that encompasses the audience in the hope of giving a truly immersive audio experience that matches the realism of the visual display.
There are only six of these Super Hi-Vision screenings in the world, three of which are in the UK, two in Japan and one in the USA, so attending one of them is a chance to see something really quite special. Every hour between 12pm and 6pm, each public viewing site receives a feed from TC0 in Television Centre. The feed is an amalgamation of Olympic highlights, which currently includes extracts from the opening ceremony and swimming events, but will be adapted to include more content as the games continue.
The challenges with this are firstly the fact that there are only three cameras available for shooting the SHV footage, so the number of different events that can be filmed are limited. There is also the issue of setting up the SHV camera rig and dismantling it to move to another location, which is no trivial matter. Finally, the process of editing the footage into hour-long highlights packages takes an extremely long time, due to the huge amount of data involved. For these reasons, the highlights package is only updated every few days.
I was lucky enough to watch the opening ceremony live in SHV, and it was pretty incredible. It was such an elaborate performance that many details would no doubt be lost even in HDTV, but SHV gives the best chance of catching all the little intricacies. Even after seeing the highlights package countless times I still pick up on elements I haven’t noticed before. Then of course there was the audio. The speaker set up really did justice to the emotive soundtrack of the opening ceremony, and more than once did I think that someone behind me in the auditorium was clapping, only to find that it was actually coming through the speakers.
So was my scepticism about public interest founded? Absolutely not. Of course, the techies love it, and when they reveal themselves by looking mildly interested we eagerly shoo them into the projection room and show off the gloriously geeky equipment. But what is particularly great is the reaction of the general public – many people have, without any prompting, expressed how impressive the experience was, commenting that it really did feel like they were at the event and asking when they can get it in their own homes. Many have told us they will return for another showing, and some already have.
There have been plenty of kids at the screenings, and they seem to find it endlessly amusing when they spot us peeking out of our little windows in the projection room. We’ve taken some of them backstage to show them how it works, and they’re clearly fascinated. One small girl was so excited about using the controls to change what appears on the cinema screen (‘WOW! Mum it’s AMAZING!!!’) I’m sure she has a career in technology ahead of her!
Super Hi-Vision is undeniably impressive, and in my opinion, a bigger improvement from HDTV than HDTV was to SDTV.
At the current frame rate of just 59.94Hz, there are issues with panning and fast moving objects. While this may be relatively inconspicuous at lower resolutions, at the resolution of SHV the blurriness this causes is very noticeable. The technology therefore works best when it is used for static, wide shots of arenas, which is actually fine considering the intention is to give the impression you’re sitting in the audience at the event.
The plans to increase the frame rate to 120Hz should go some way to addressing this issue, which may extend the range of shots capable, making it appropriate for more situations. It has been argued that further increases of spatial resolution beyond UHDTV would be negligible, so I think concentrating on improving temporal resolution is the way to go (there is a demo at R&D of 300Hz and it really is strikingly good).
The consequences of increased frame rate, of course, is the increase in the already massive amounts of data involved in the system. We locally recorded the live stream of the opening ceremony, and it takes up hundreds of gigabytes on our fifteen terabyte hard-drive, and that’s only at 59.94Hz. This could be one of the limiting factors in how soon this technology will be commercially available.
Speaking of which, you may be wondering when you’ll be able to have this technology at home. Originally, it was thought that we would be waiting until something like 2020, but NHK have recently developed a prototype light-weight SHV camera which has brought estimates of the first UHDTV broadcasts down to 2016. I’m afraid you’ll also need to invest in an 8K monitor and 22.2 surround sound speakers, so you might want to start saving now…
I really recommend getting to a screening if you can, it’s worth seeing and so far the audiences have loved it. You can get your free tickets for Bradford from the National Media Museum, or from BBC shows and tours for London and Glasgow.
I’ve learnt a lot and it’s great to be a part of bringing such novel technology to the public. I’ve really enjoyed working alongside both NHK and the National Media Museum. If only the projection room didn’t have to be so cold!