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UHD to the Home – Ultra HD over the Internet

As part of its presence at the Commonwealth Games, BBC Research & Development currently has a number of ultra high definition (UHD) television screens at both the Science Centre in Glasgow and New Broadcasting House in London showing live coverage of the games. These screens are open to the public for the duration of the Commonwealth Games and free to view for visitors between 10am and 5pm in Glasgow and 12 midday to 3.30pm in London.

The pictures and sound for these screens is being delivered over the internet – from capture, through the full production chain, and finally to decoders and displays in the demonstration areas. This entire process normally requires very specialised and expensive television broadcast equipment but in this case it is all being handled using normal IP networks and commercially available computing equipment. Below you can see a short video produced by R&D engineer Alia Sheikh which explains the work the department has been engaged with in this area and the reasons why BBC R&D thinks IP delivery is the future for TV delivery.

For the Commonwealth Games BBC R&D’s IP TV delivery infrastructure is spread over a number of different locations to demonstrate the flexibility that an IP based production system brings. While pictures and sound are being captured in the venues, the audio gallery providing the commentary is in London and the television production gallery is located in Glasgow. Below you can see how our IP based end to end infrastructure is spread across the UK to deliver UHD TV to our public demonstration areas.

While delivery of television by IP is on the increase, a lot of people still receive their television using traditional transmitters and receivers and will do so for some time to come. Not all of the UK has reliable high speed internet connections so alongside IP delivery, the department is also demonstrating the transmission of UHD content over the existing Digital Television Transmission (DTT) network. BBC R&D are working with the rest of the broadcasting industry to ensure that the standards exist to distribute UHD content to as many people as possible no matter the delivery method.

Motion Blur – The Challenges of UHD

Beyond the challenges of delivering UHD content to people’s homes there’s also the issue of how to get it working properly once it gets there. One challenge is that with higher visual definitions motion blur becomes more of a problem for video images, especially with fast moving subjects like the athletes at the Commonwealth Games.

One solution is to increase the frame rate of the television (the rate at which the image on screen is refreshed) from 50fps to 100fps. To sharpen motion, you can also shorten the camera shutter speed, but at conventional frame rates this leads to judder. A frame rate of 100 fps enables the eye to fuse motion in a realistic manner, even with a short shutter opening and is also high enough to avoid visible flicker. BBC R&D is involved in ongoing discussions with other European broadcasters to create standards for UHD frame rates. The image below shows a comparison of shutter speeds of 1/100 and 1/300 of a second.

Exciting New Opportunities

Along with the technical challenges IP-delivered UHD TV presents to the engineers at BBC R&D, it also provides a host of new production and editorial opportunities. One major advantage of building an IP based system is how configurable it is.

A television studio is a collection of very specialised pieces of equipment, very often with only one purpose each – a vision mixing desk for example or a preview monitor. Moving from a hardware to a software based system means that devices can be reconfigured to the needs of different production teams quickly and at little expense. The gallery production equipment in R&D’s experimental IP based television production gallery uses consumer computing hardware so a tablet can be a production schedule one day and a sound mixing desk the next. Or both. This reconfigurable nature of IP based production drastically reduces cost and increases working flexibility.

The BBC has always delivered high quality crafted television, first in black and white, then colour, using both analogue then digital delivery methods and most recently moving from standard definition to HD. UHD TV and IP based production are another evolution of the art form that provides the organisation with yet more exciting opportunities to make the best television we can and deliver it to audiences in increasingly cost effective ways. BBC Research & Development’s work ensures that when the UK is ready to switch to UHD, the BBC will be as well.

To take a look behind the scenes at a working IP television production gallery please visit us at the Glasgow Science Centre between 10am & 5pm for the duration of the Commonwealth Games. You can also watch live UHD coverage of the Commonwealth Games delivered both over IP and using digital television transmitters. Finally you can get hands on with some of the exciting new experiences that UHD video and IP delivered TV make possible including a chance to look around a 3D live video of the Hydro Stadium using the Oculus Rift headset.

 

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HDTV High-definition television in the United Kingdom

High-definition television in the United Kingdom is currently at an early stage of adoption. The first broadcasts began in 2006 and the number of channels has grown to 32 as of late 2008.

Most channels in the United Kingdom remain broadcast, and largely viewed, in standard-definition but most major broadcasters have begun or are soon beginning their initial forays into high-definition television. Similarly, the vast majority of viewing still takes place in standard-definition though penetration of high-definition displays and receivers is increasing.

High definition broadcasts are currently available over digital satellite, both subscription and free-to-air, as well as digital cable. Limited trials of over-the-air high-definition television broadcasts have been undertaken and there are plans for permanent broadcasts following digital switchover.

Current status

High-definition broadcasts are available on free-to-air digital satellite, the Sky+ HD satellite service and Virgin Media (cable) with BBC, ITV and Channel 4 channels available under contracts that expire in 2008. A new service, called Freesat launched on 6 May 2008, initially carrying the BBC HD channel. ITV have been trialling part-time HD broadcasts via the red-button service, ITV HD at first exclusively available on Freesat, although the service can now be manually tuned in on certain other satellite receivers including the Sky+ HD box. Channel 4 broadcasts selected programmes in HD via Sky HD and it is anticipated that they will eventually also broadcast over Freesat.

The BBC HD channel is available without subscription on digital satellite, and may be received by anybody with suitable equipment — a high-definition satellite receiver and a satellite dish. Many satellite viewers currently opt for a full Sky subscription which provides extra channels.

 Broadcasters

BBC

The BBC initially operated BBC HD on a trial basis on Sky Digital & the Telewest cable (later Virgin Media) platform. Following full approval by the BBC Trust, the service is expanding its hours and aims to become a full-time service.

 ITV

The ITV Network started broadcasting a trial service on digital cable television as well as on the Digital Terrestrial Television trial in London during the 2006 Football World Cup. The service ceased after this period, but a new HD service began to be made available with the launch of Freesat, on 7 June 2008, where selected programmes are offered in HD format, and accessed by the red button on Freesat receivers. ITV intended to spend £10m during 2008 on supporting ITV HD. Currently, there are no plans to launch via Sky.

Channel 4

Channel 4 launched its HD service on digital satellite in December 2007. The channel is encrypted, but is available with a free-to-view viewing card. There is some speculation that the channel may go free-to-air alongside BBC HD when its current contract with BSkyB expires.

Five

Five does not yet operate any HD service, but has been awarded a licence for HD transmissions on Freeview from 2010. The content is expected to be a simulcast of its main channel, with own productions and US acquisitions in HD.

Sky

British Sky Broadcasting began HD transmissions of several channels in May 2006.

Platforms

Terrestrial

As yet, there have been no full-time terrestrial HD transmissions other than two low-power trials in London. Although the spectrum used to broadcast digital television is currently too limited to allow HD transmission, the industry expect that new transmission and compression formats will allow full-time HD channels as early as late 2009.

Satellite: Sky HD

Sky+ HD has been carrying HD channels since May 2006. The platform now has a mixture of 33 free and subscription channels broadcasting in HD.

Satellite: Freesat

Freesat launched on 6 May 2008. It provides a subscription-free alternative to Sky and includes support for HD (BBC HD & ITV HD are available to receive with the Freesat HD box).

Freesat is a not-for-profit company formed by the BBC and ITV, marketing itself as being completely free from subscription charges or contracts, although viewers of course are obliged to purchase a suitable satellite receiver and have a satellite dish installed if they do not already have one. Freesat receivers are available in both standard definition and high definition cable versions. HD channels are available only when the satellite receiver is capable of supporting it.

Cable: V+

Virgin Media cable carries the BBC HD channel and on demand content from several broadcasters as part of its V+ service.

IPTV: BT Vision

BT Vision, a hybrid digital terrestrial and IPTV service, carries pay-per-view high-definition programmes, which the viewer downloads to the BT Vision set-top-box then watches when the download is complete. The HD service launched in February 2009.

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