2011 Introduction for 3DTV Set-Tops
The first 3D broadcast TV services from satellite operators DIRECTV and BSkyB will both use existing set-top boxes but this means the full HD resolution provided in a 2D service must be divided between the left and right eyes. After consumers have been introduced to the concept of 3D, platform operators can migrate to ‘full’ 3D transmissions, with full HD for each eye.
The first set-top boxes specifically designed for 3D video with optimised resolution and frame rate will start to hit the market in 2011, according to a spokesperson at STMicroelectronics, which announced a new generation of decoder chips in January that can support 3DTV and a 3D Electronic Programme Guide (EPG). The STi7108 chip also supports advanced Internet content and high performance gaming, with a view to enabling 3D gaming on set-top boxes.
Previous generations of the STi7108 could support half HD full motion video with 2D, 2.5D or 3D graphics effects. These used side-by-side video formats and achieved 1080p HD at 24 frames per second (equivalent to Blu-ray frame rates). The new chip supports HD full motion and can use left/right 3D picture formats. 3D set-tops based on this silicon will be able to handle up to six transport stream inputs and provide the full-motion HD 3DTV over HDMI 1.3 with HDCP copy protection.
“3D graphics really does help the EPG come to life in a 3D video environment, and without them it will look flat,” says a spokesperson, who adds that there will be a cost associated with implementing a quality 3D graphics engine to support the new kind of EPG and 3D gaming.
STMicroelectronics says it is seeing a very high level of interest from operators and set-top box vendors in the new decoder product. It will be seen in set-top boxes “in the near future”.
Paul Entwistle, Chief Technologist at set-top box vendor Pace, believes broadcasters, and especially satellite operators, have the bandwidth to deliver the higher quality 3D television, but they can showcase 3DTV using their legacy set-top boxes and migrate to new devices when the services are established.
He points out that 3DTV could become a major differentiator for broadcast networks compared to the Internet. Citing bit rates of 30Mb/s for 3D video on Blu-ray, he wonders whether consumers could be expected to download such amounts of information across broadband to a PVR. One challenge for the mid-term will be how to deliver 3D and 2D versions of content simultaneously in the most efficient way.
“You could imagine that 3D starts as a niche channel showing movies but as more content needs to be delivered in 3D, you will not want to transmit an HD version and a 3D version because of the bandwidth costs,” Entwistle says.
Entwistle thinks the broadcast industry will draw inspiration from the Blu-ray 3D specification, which supports full HD 1080p resolution to each eye and calls for encoding using the Multiview Video Coding (MVC) codec, an extension to the MPEG-4 AVC (H.264) codec currently supported by all Blu-ray Disc players. MPEG4-MVC compresses both left and right eye views with a typical 50% overhead compared to equivalent 2D content, and can provide full 1080p resolution backward compatibility with current 2-D Blu-ray disc players.
Pace believes 3D has the potential to become a mass-market service in time. “You can show consumers something very different to what you had previously – it is a substantially different service,” he comments. “It could be the games community – which is a natural 3D environment that will pioneer the take up of 3D displays but whoever it is, the services from Sky and ESPN will give more and more people the chance to see 3D.”
By John Moulding, Videonet
