From the gravel drive that winds through the approach to Kingswood Warren, there is no clue to what takes place behind its imposing front door. Tucked inside the M25 near Epsom in Surrey, this rambling neo-gothic mansion has served as a country estate, a finishing school and a hotel. But there are no lords, guests or young ladies here today.
I am greeted by Andy Bower. He takes me into the lobby, where the moulded ceilings lift, and light floods through from the dining room. "Japanese and American engineers are always amazed when they come to visit 'the castle'," he says.
Himself an engineer, Bower arrived as a trainee in 1983. Today, he is the controller at Kingswood, which for 60 years has been the BBC's Research and Innovation Centre. In a maze of windowless labs and studios, engineers have beavered away to achieve some of the biggest milestones in broadcasting.
The Japanese-made plasma screen in the lobby owes its existence to the ground-breaking work on HD TV that took place here. And it's not alone. DAB radio, Teletext, Nicam Digital Stereo, Freeview, the "red button" that lets us "go interactive" – you might expect technological developments like these to have come out of a lab in downtown Tokyo, or Silicon Valley. "It's a lovely environment to work and think in," Bower says. "I think it definitely adds something to the job."
But, later this year, Bower and his colleagues will leave Kingswood, making a new home at the BBC's state-of-the-art Salford media centre, due to open in 2011, via temporary accommodation at the corporation's west London headquarters.
Until then, the 100 or so engineers, scientists and mathematicians who work at Kingswood can pause to reflect on a glorious history, which has seen the centre's trophy cabinet swell with dozens of technical awards, including four Emmys.
One of Kingswood's proudest achievements is High Definition (HD) television, which it developed in partnership with other broadcasters, including Japan's NHK. "It was the first project I worked on when I joined as a trainee in 1983," Bower says. "Back then, we were doing fundamental studies on how many lines there should be, and how wide the screen should be."
By the Nineties, Bower and his team had put together an HD outside broadcast unit in an old van. "We went to Paris and to horse races with four standard-definition, digital-video recorders – the first of their kind, which we used in parallel to capture high-definition images."
Bower then used a very early Sony HD TV to play back the four streams of footage, which the bulky, 164kg TV knitted into a single, high-definition picture, setting the benchmark for the medium. "The quality was excellent," Bower recalls. "The pictures were comparable to today's best plasma screens – some say even better."
Meanwhile, work goes on at Kingswood on the next generation of broadcasting systems and devices. In an upstairs room in B block, a Fifties extension to the 19th-century house, Dr John Zubrzycki has been tasked with predicting the next big thing in television.
"I'm looking after a project called Beyond HD," Zubrzycki says. "It's very hard to predict the future and anticipate when the electronics industry will push the next thing after HD and plasmas."
One possibility Zubrzycki is investigating is 3D TV. In a corner of the room, he shows me a 42-inch LCD TV bought from Phillips for about £6,000. It looks like a standard, widescreen box, until you notice the extraordinary quality of the images, which, without the need for any glasses, jump right out at you.
It works thanks to a film of tiny lenses that covers the screen. Each lens sits over each of the millions of red, green and blue pixels that make up the picture. The lenses send different images to the viewers' left and right eyes, mimicking our stereoscopic view of the real world.
"We bought it to show people in the BBC that this is where we see 3D going," Zubrzycki says. "And we're collaborating with Phillips, and others, to start a two-year project to work out the technical elements of a full 3D broadcast chain – from camera, to aerial, to screen."
Another project on Zubrzycki's books is what he calls, simply, "very large" screens. "A few years ago, nobody wanted a 50-inch screen in their living room, but now they're selling like mad," he says.
With a flick of a switch, Zubrzycki fires up two HD projectors the size of car engines. Working in tandem, they bathe the entire far wall in a startlingly sharp view of a field of sunflowers. It's hard to imagine watching EastEnders or even Star Wars on a screen this big, but Zubrzycki's approach is different.
He and his colleagues in the electronics industry are looking at the possibility of turning an entire wall of the home into a giant computer desktop. "You could watch the news or a film on a smaller section, or have lots of different views at once, with other applications in different parts of the screen," Zubrzycki explains.
Deeper in the bowels of B Block is an old television studio, which was once used to film Bill and Ben the Flowerpot Men. There, Bower introduces me to Graham Thomas, who runs the BBC's Production Magic centre. He is responsible for the technology behind Peter Snow's Swingometer, the virtual backdrop on election night, and the lines and arrows that sports pundits use to show the paths of everything from footballers or table-tennis balls.
But Thomas has more than graphics up his sleeve, and his newest project, which he gleefully demonstrates, is nothing short of breathtaking. "We're familiar with adding surround sound to an existing system," Thomas says, "so we asked ourselves, could we do something similar with video – give people a device to bolt on to the TV that would immerse them in an environment?"
To find out, Thomas and his colleagues locked themselves in their studio for a week and created a prototype of the world's first surround video system. In a corner of the room stand two sides of a mocked-up sitting room, complete with white screens for walls, a plastic chair for a sofa, and real widescreen TV at the front.
First, Thomas switches on the TV, which shows rather dull footage of trains trundling along London's Docklands Light Railway. Nothing impressive there – until he flicks another switch. Suddenly, the image on the screen is extended in all directions, filling the entire room. My peripheral vision filled, it feels as if I am no longer in a studio, nor even a living room, but on the train itself. The effect is extraordinary, especially given the uninspiring subject. "Imagine watching Spiderman on it," he says, with a glint in his eye.
Like all the best ideas, Thomas' surround-video set-up is brilliantly simple. He and his team bolted two standard cameras on to a specially made frame. On one, they fixed a standard lens, while the other sported a "fish-eye" lens – a super-wide angle device that captures not only what is in front of it, but everything in the periphery, too.
Back in the studio, footage from the camera with the standard lens is fed into the TV as normal. But the fish-eye footage is fed, separately, into a standard projector directed towards the back of the room. There, a hemispherical mirror, like those used to give security cameras a greater field of vision in shops, reflects the image back over the ceiling, walls and floor at the front of the room.
Before it reaches the projector, the fish-eye footage is run through a computer, which distorts it to compensate for the shape of the mirror, which is the size of half a medicine ball, and the square layout of the average living room. "It would be down to you and your wife how many pictures you would want to take off the walls," Thomas says.
Surround video came out of what is called, in BBC speak, "rapid prototyping" – where employees are invited to submit weird and wacky ideas in brain-storming sessions – and is a classic example of the kind of inspired thinking that has made Kingswood a world-leader. "Surround video is something that might never happen," Thomas says. "It's very futuristic, but that's our job – to look years, even decades, ahead and predict what is going to be the next big thing."
On the gravel drive outside the oak front door, Bower escorts me back to the real world, and contemplates the closure of Kingswood. "It's something we've been talking about for years," he says. "It makes sense, because we'll be along the corridor from colleagues in other departments, rather than two hours away by train. But yes, it will be sad to leave after 25 years. This is a special place."
Past successes...and a glimpse of the future
Nicam Digital Stereo
The worldwide standard for transmitting stereo sound was developed at Kingswood in the Eighties, launching in 1986.
The BBC helped to develop the precursors to today's HD plasma screens back in the early Eighties.
Heralded as the future of radio, digital audio broadcasting started with tests conducted by Kingswood engineers in 1983.
The BBC worked with the Moving Picture Experts Group to develop the video standard, commonly used for online video clips, in 1993.
The Radio Data System, the technology that displays the radio station name on your car stereo, and lets you stay tuned in on the move, or even pick up traffic news, was demonstrated here in 1983.
The service used by millions to check football scores, cinema times and the news headlines came into existene at Kingswood in 1985.
Projectors with special lenses could one day turn your entire lounge into a TV.
Free satellite broadcasts in places where the Freeview TV signal is weak.
High-definition signals small enough to be received on a standard TV aerial.
Once the preserve of specially equipped cinemas, 3D could be coming to a screen (very) near you.