Arqiva Mulls 3D Transmission Options
Arqiva has discussed possible future options for delivering 3D broadcast services over the UK's digital terrestrial television network. In a speech yesterday at the Digital TV Group Summit, Arqiva head of technical development Mike Brooks said that there are "lots of different" ways to bring 3D to the home. However, he focused on Plano-Stereoscopic 3D, which involves bringing 3D pictures to flat 2D displays by delivering images for the left and right eye to be viewed with specialist glasses. Viewers can either use passive 3D glasses, which are cheap but require expensive TV sets as the polarisation is done on-screen, or active glasses incorporating mechanised shutter technology, which are more expensive but use cheaper sets.
For its 3D channel, Sky is using 'side-by-side' broadcasts in which 2D and 3D feeds are run alongside each other to ensure a seamless simulcast to the receiver. Brooks confirmed that side-by-side is a viable option for DTT, alongside an 'over-under' approach using similar technology, but the problem with delivering 3D content over a 2D terrestrial schedule would be degradation or big jumps in picture quality between programmes. However, Brooks said that broadcasters could address the problem with a 'controlled access' approach, in which 3D programmes are simulcast via the Red Button.
A big issue for Freeview or Freesat customers could be the additional cost of purchasing 3D receiver equipment and a new 'Tridef' TV set, with the latter initially costing between £1,500 and £2,000. Possibly a bigger problem, though, would be the extra capacity required for supporting 3D transmissions on DTT using new compression encoders.
Sky's 3D feed uses a 16Mbps bandwidth allocation to operate effectively, as the duel HD streams required to create the 3D picture lose resolution and so the frame rate has to be increased. Such a high bit rate is possible over Sky's satellite network but would seem a complex challenge on DTT. Brooks said that 3D on DTT would most likely require up to 20% additional capacity, but Arqiva expects improvements in encoder technology to make that more possible in the future.
Arqiva is now setting up tests of 3D broadcasts and working with the DTG to create a 3D TV specification as part of its new D-Book 7 technical standard. However, Brooks said that getting 3D on DTT is really "up to the broadcasters".
Also speaking at the DTG Summit, Sky's director of product design Brian Lenz said that 3D was always on the satellite broadcaster's "wish-list of crazy things to look at, alongside smell-o-vision and so on". However, early trial broadcasts such as a Keane concert at London's Abbey Road studio gave Sky the confidence that 3D could be delivered to customers on a viable basis.
Lenz said that the various 3D consumer trials run by Sky since then have "tested better than anything we've done in the past ten years". Sky's 3D channel will launch to selected pubs next month, before expanding to Sky's top tier TV customers later in the year when more Tridef sets are available. Lenz said that Sky is happy to support both active and passive glasses at the moment, which he views as a sign of consumer choice rather than a "format war". However, he stated his belief that Auto-Stereoscopic TVs, which create the 3D image without the need for glasses, are the future but one that is 10 to 15 years away.
Echoing comments by Avatar director James Cameron, Lenz said that Sky wants 3D to "create a window to reality" which helps viewers forget that they are watching a static screen.
Alongside Sky's own 3D service, Lenz said that more channels could become available in the future, such as ESPN's forthcoming 3D offering in the US, but that would most likely be a longer-term strategy.
When asked about possible nausea for viewers, Lenz said that Sky is running research to judge the physical effects of watching 3D images for sustained periods. However, he stressed that most discomfort issues are down to how the programming is shot in the first place, a subeject which Sky has learned about from its production trials.
By Andrew Laughlin, Digital Spy
