Incomplete 3DTV Products in CES Spotlight

In a wide range of demos, companies will claim at the Consumer Electronics Show in January that stereoscopic 3D is ready for the home. In fact engineers face plenty of work hammering out the standards and silicon for 3DTV products, most of which will ship for the holiday 2010 season.

Hollywood studios are driving 3D to the home as a way to make more money on a growing number of successful 3-D titles at the theater ranging from Avatar to Up. A standards effort launched in June to define a content format for stereo 3D movies was one of the first major actions in this direction.

Much more is still ahead. Observers expect many demos at CES of 3DTV sets using content from stereo-3D enabled Blu-ray players, thanks to a newly minted Blu-ray spec for stereo 3D. However most of the players and many of the TVs will not be available until later in the year when new chips for the spec are available.

Beyond the Blu-ray effort, multiple standards and chips based on them are still in progress. The latest is an upgrade of the HDMI interface that will pave a way for future stereo 3D broadcasts to be available on new and existing HDMI links. The HDMI Licensing group is adding support to its version 1.4 spec for the top/bottom format that many broadcasters are expected to use. The format squeezes information about left and right eye images on to a single frame to save bandwidth, albeit at a loss of some resolution. An HDMI implementation of the top/bottom format will be defined in meeting of the group in January.

"I have been told by the technical team that this is not a hard exercise," said Steve Venuti, president of HDMI Licensing LLC. "When we launched 1.4 in June, we did not launch a mandatory format for broadcasters because we were not sure where broadcasters would go," said Venuti. "Since then, we've been polling anyone who might have a take on this and what came across was they wanted to implement top/bottom which we did not put in 1.4," he said.

The HDMI group has talked to CableLabs, DirecTv and content companies including HBO about the changes for stereo 3D. Venuti said he did not know whether the new format will require changes to HDMI 1.4 silicon already in the works.

3D Moving "Fast and Furious"
The HDMI group also is relaxing its specs so that many existing set-top boxes and TVs do not have to handle a variety of previously mandatory formats often beyond their processing capabilities or needs. Instead they can handle stereo 3D broadcasts in the top/bottom format with a firmware upgrade.

"Of all the HDMI 1.4 features, 3D is going faster and more furious than we thought, certainly from the broadcasters," said Venuti. "Everybody is lined up behind 3D, so it will be a big launch next year," he added.

The HDMI work grew out of conversations between the group and a related working group in the Consumer Electronics Association, CEA 861.

"There are improvements expected as new silicon supports higher transfer rates on the interface, [but] the intent [also] is to have existing equipment be as functional as possible," said Brian Markwalter, vice president of technology and standards at CEA. "That's critical because without HDMI support, we won't get anywhere [in 3D] in 2010," he said.

Ultimately OEMs will have to support many formats for stereo 3D content. The ideal is to provide sequential left and right frames at twice the desired viewing rate. However because broadcasters and some devices may lack bandwidth for that approach, a number of alternatives have been used. Broadcasters appear to be rallying around top/bottom, however Venuti said trials are still on-going. Other approaches that involve some form of compression include checkerboard, side-by-side or interleaved rows or columns.

"I think the TV will have to have a lot of electronics to recognize all the formats and transcode and convert them to the native rate of the TV," said Chris Chinnock, president of market watcher Insight Media. "It sounds complicated but if you think about all the frame rates we initially had to support in HDTVs for cameras and TVs and so on, you see TV makers know how to handle this kind of situation," he said.

BSkyB announced it will start stereo 3D broadcasts in the U.K. in 2010. Other broadcasters may announce plans at CES, but Chinnock said he expects them to go slowly.

"They will probably start with a very simple sampling technique and get a service started with minimal impact on bandwidth," he said.

A Broadcom executive recently said he expects 3DTVs to start shipping in volume in late 2010. They will need about $100 in new silicon, he estimated.

Of Eye Glasses and Captions
3DTV standards in two other areas are still in process—active eyewear and captions. A CEA group set up earlier this year has decided it will set a standard for infrared signals used to control active shutter glasses. The group is working on a requirements document and expects to have a broad call for proposals in January. The group could have a spec done in less than six months if it doesn't have to resolve conflicting proposals from major suppliers.

"Everyone is aware of the market pressures to get this stuff out, and [the group has] all the players you would expect participating," said Markwalter of CEA.

Different display technologies will use a variety of different kinds of active and passive glasses. Philips folded in April an effort to define an autostereoscopic technology that required no glasses because it had a narrow viewing range and had a relatively high loss of resolution and brightness.

The CEA also has a task group studying how to place captions in 3D space. It is expected to issue a call for proposals in January. "This is another one of the pieces slowly coming together as we think about all the systemic issues for rolling out 3D," said Markwalter.

CEA set up earlier this year a task force to investigate any areas where standards are needed. "They are the first filter for any standards projects on 3D at CEA, but don't do the standards themselves," he said.

By Rick Merritt, EE Times