September 9, 2009 – In a challenge to take-it-slow 3D strategies elsewhere, BSkyB has promised to launch a channel devoted to 3D content next year on expectations 3D HDTV sets will be in the market, obviating the need for special set-top boxes.
The satellite provider, now serving 9.4 million or about a third of British households, is still working out details but makes clear the 3D channel will be available to all subscribers with HD digital set-tops and 3D-ready TVs. With plans for launch of a “pull” video-on-demand service next year, BSkyB could well offer 3D on both linear and VOD content, says Brian Lenz, head of product design at BSkyB.
“Whilst we are fully committed to launching a full 3D TV service, we’re still in a developmental stage, and have not finalized the proposition yet,” Lenz says. “As we are reusing our HD infrastructure, we will have the flexibility of using both linear and VOD capabilities to deliver 3D to customers.” The new VOD service, offered over broadband to IP-capable HD set-tops, complements the “push” on-demand service the company offers via satellite.
The ambitious 3D project leaps ahead of the rest of the European and U.S. markets, which remain at the starting gate wrestling with a range of issues, including what levels of bandwidth will be required, what should be the standard approach to distribution of the twin-view stereoscopic pictures that create the 3D and concerns over availability of content (see accompanying story). None of this should be a barrier to getting started, Lenz asserts.
“The aim of our 3D service is to harness the existing investment in our HD infrastructure, including all Sky+HD boxes past, present and future,” he says. “No new software or firmware is required in our boxes.”
Customers will be able to buy 3D-ready HDTV sets in the U.K. next year. Sky’s commitment to serving such customers with 3D content follows extensive research and development activity into 3D, Lenz says, noting that Sky became the first TV company in Europe to broadcast a live event in 3D TV on April 2 with broadcast of a performance by Keane live from Abbey Road Studios.
Lenz stresses Sky’s technique for distributing 3D content achieves quality goals without requiring new distribution infrastructure or additional HD channel bandwidth. “By harnessing our investment in HD we are able to significantly reduce the barriers to customers adopting 3D TVs by removing the requirement to buy a new set top box,” he says.
“3D transmissions are broadcast within the traditional range of Sky’s HD broadcasts; similar to a high-end sports broadcast at about 18 megabits per second,” he explains. He says Sky now is offering 34 HD channels to 1.3 million HD customers.
He suggests that worrying about bandwidth as a gating factor to 3D makes no sense. “As compression algorithms evolve, bandwidth efficiencies for stereo 3D broadcasting will improve as well,” he says. “But the important point is that existing HD platforms are already positioned to deliver 3D TV within their current HD broadcast economics, particularly satellite, which can more easily expand or add bandwidth for HD channels.”
3D TV is possible because of a series of major breakthroughs (principally in camera, post-production, encoding, set-top box and TV set technology), which means that domestic TVs are now capable of processing an image in a way that can deliver depth information to the brain – much like the human eye does. Polarized glasses are currently used to help direct the correct left or right full color on-screen image to the corresponding eye. The brain then processes each feed to create a single image, providing a level of depth and focus which means that the content is able to move to and from the foreground and therefore becomes three-dimensional.
“Sky is embedding the left and right images into a single HD frame, which can then be passed through the existing infrastructure to the TV,” Lenz explains. “From there the 3D TV will process the signal to deliver 3D images to consumers using passive or active glasses.”
Lenz says other means of delivering 3D are at hand, but this approach was best suited to the Sky environment. “There are experimental formats for delivering 3D images using ‘2D + DOT’, where a single image is broadcast along with depth information in a lower bandwidth broadcast transmission,” he notes “However, this method requires all new broadcasting and receiving equipment, making it impractical for making a real impact on the market at any time in the near future.
“Alternatively,” he continues, “Blu-ray is cementing a standard using 1080p50 delivery of 3D content, where the left and the right eye are delivered as alternating frames in full 1080p25 resolution. This requires twice the bandwidth of even the highest sports HD broadcasts, and is not viable for a broadcasting standard, but is entirely valid for packaged media.”
Lenz asserts the emergence of various formats at this early stage of development is a positive factor, notwithstanding concerns that lack of standardization could thwart public uptake of 3D.
“Interest in 3D via any format is positive for Sky as it serves to encourage wider awareness of the format,” he says. “The presence of both Blu Ray 3D and Sky 3D will only serve to stimulate the emergence of a 3D market more rapidly.”
In a video interview with Broadband TV News, a European news feed, Lenz amplifies on this point. “In general standards are not developed by committees and then brought to market, standards are developed by commercial ventures into the marketplace to set and form that standard,” he notes. “What we’re doing is actually reusing the HD format and embedding two images into that, and whether you do it side by side or top down it’s non-proprietary, it’s simply an open format. It’s encoding, and it’s re-using the HD infrastructure, and we believe that that is the way to get the best quality stereo 3D signals to customers in broadcast.”
The U.S. cable industry is less sanguine about taking a wide-open approach to getting 3D off the ground, preferring instead to establish some specifications for cable delivery of such content. The Society of Cable Telecommunications Engineers (SCTE) has begun to investigate the standardization required for the carriage of next-generation 3D content on cable networks amid CableLabs efforts to work out some of the technical details.
The SCTE Engineering Committee, which oversees the Society’s development of technical standards covering all aspects of cable networks, has approved a project to examine the delivery of 3D content over cable networks.
The new SCTE project, “3D over Cable,” will focus on identifying necessary or desirable changes to existing SCTE standards, including transport protocols, to facilitate the provision of 3D content by cable operators. “The long-term delivery of next-generation 3D content will be strengthened by the adoption of uniform engineering and technical criteria,” says SCTE Engineering Committee chairman Charlie Kennamer, noting the organization will take into account standards work being conducted in other organizations such as the Society of Motion Picture and Television Engineers and the Consumer Electronics Association.
Lenz acknowledges that, eventually, standards will be required, but not in a one-size-fits-all mode. “What you do need is a standard for Blu-ray or packaged media; you need a standard for HD transmission infrastructures, and you need a standard for free-to-air transmission infrastructures should they ever find a way to address that market,” he says. “But you shouldn’t constrain any one of those platforms to the limitations of another platform.”