3DTV Warning: Poor Quality Could Poison the Well
The challenge faced by programmers and carriers alike is that there's not a lot of 3DTV content available yet. A small group of early adopters may tolerate a limited 3DTV library early on, but the tech won't be nearly as appealing to the mainstream until there's a large catalogue of TV shows and movies to be viewed on the pricey sets, a conundrum the HDTV market also faced in its early days.
That content gap could cause some to convert existing 2D content into 3D. In fact, some TV makers are building in chips that can do just that, said Paul Gagnon, director of North American TV Research for DisplaySearch, during a session last week on the potential for 3DTV.
Although that could boost the value of new 3D-capable sets, converting 2D video to 3D comes at some peril, he warned.
"The quality is nowhere as good as native 3D content," Gagnon said of today's 2D-to-3D conversion technology, "but it does give the consumer something to watch. But that [strategy] could poison the well… if the quality is bad."
Some early work with stereoscopic 3DTV has already shown programmers and MSOs that they can't skimp on the bits. One case in point was cable's live, on-demand 3DTV coverage of the 2010 Master's golf tournament earlier this year. (See Comcast Courts Early 3DTV Adopters and Photos: Comcast Tees Up 3DTV Masters.)
For typical HD-VoD content over MPEG-2, cable has used a "safe harbor" threshold of about 15 Mbit/s. However, tests showed that quality suffered when 3DTV content was encoded for VoD at 15 Mbit/s, noted John Vartanian, chief technology officer of In Demand LLC , a partner in Comcast Corp. (Nasdaq: CMCSA, CMCSK)'s Masters 3DTV project.
To ensure that the on-demand version of the coverage was of high quality and generally artifact-free, it was decided to encode that content at 18.75 Mbit/s. That decision showed "a visible improvement," Vartanian said. [Ed. note: Comcast's live MPEG-2 feed of The Masters was also delivered at 18.75 Mbit/s -- about the same it tends to use for a 2D HDTV feed. However, less bandwidth is required for ESPN3D because the new part-time channel reportedly uses the more efficient MPEG-4 codec.]
The exercise proved that 3D-VoD will likely require richer encoding, but there's no rule of thumb yet for "frame compatible" 3D content, which combines two half-resolution HD signals that can be used for legacy digital set-tops.
Vartanian said a future 3D-VoD standard will have to use a higher encoding rate than the standard for traditional HDTV. "It'll be 1.x the standard, but we don't know what the 'x' is," he said, noting that most believe the bandwidth premium to be in the range of 10 percent to 50 percent.
The 3DTV market
But there's still time to figure it out. Despite all the hype around 3DTV, "it's still a relatively niche segment," said Gagnon.
He said North American "will really be the launch region for 3DTVs," noting that 66 percent of 3DTV sales will be in that region this year, with two thirds of that in the US, followed by Japan (14 percent) and Western Europe (13 percent).
But 3DTV sales will represent just a sliver of the overall TV market. Gagnon pegs the overall TV market at about 225.9 million units, but expects only about 2.5 million 3DTVs to be sold this year. However, based on sales bumps expected for the second half of this year, Gagnon said he may revise his 2010 3DTV forecast to between 3 million and 3.5 million units.
Still, some programmers and content aggregators are banking on the future of 3DTV, despite its expected slow start. Among them is Avail-TVN , which intends to launch two linear 3D channels and some VoD-3DTV fare by the fourth quarter of 2010. (See Avail-TVN: All 3D, All the Time.)
Avail-TVN CTO Michael Kazmier agreed that premium bandwidth will be needed to keep quality high when using half-resolution stereoscopic 3D. "The boat anchor is the legacy set-top. Some artifacts can show up in the conversion, so you have to throw more bits at it," Kazmier said.
MSOs such as Knology Inc. (Nasdaq: KNOL) are taking a wait-and-see approach, though the operator is "cautiously optimistic" about the technology, said Rickey Luke, Knology's CTO, VP, and chief scientist. Knology doesn't have any firm 3DTV plans yet, but Luke admits that "cost is going to be a driver" for consumer adoption just as it was in the early days of HD.
However, long-term, he said he sees the potential for "full" HD3D using the emerging Multiview Video Coding extension for MPEG-4, which Blu-ray intends to use for 3D.
Buddy Snow, senior director of global product marketing for Motorola Inc. (NYSE: MOT)'s Home business unit, acknowledged that anything beyond half-resolution 3DTV will require new set-tops. "But the visual results are outstanding," he said, noting that cable should have a bandwidth advantage in this area over its satellite rivals.
But he warned that operators that don’t do 3DTV early on can't afford to stand on the sidelines forever. "Even if you don't do it, your competition will," he said.
— Jeff Baumgartner, Site Editor, Light Reading Cable