Philip Hunter /
02.14.2011 12:45 PM
Europe determined not to miss out on 3-D standards

Europe never played its full part in the development of HDTV, but it is making up for that with 3-D TV, with a number of vendors and operators heavily involved in the current standardization efforts. These have been most notable on the satellite front, with French operator Eutelsat spearheading efforts to ensure European interests are represented as the industry moves toward agreed standards for production, archiving and distribution of 3-D content.

Although a few major operators, such as BSkyB and Virgin Media in the UK, already offer some form of 3-D services, these are far from the finished product, which will almost certainly avoid the need for wearing of glasses and will incorporate various enhancements yet to be developed. The 3-D standards process, therefore, is ongoing and in a state of flux, with disagreements within and between the various groups even over the extent to which 3-D should be deployed at all, and certainly whether it will remain a niche service.

There are also medical factors to consider, given that it is still unclear whether 3-D viewing using current technology can cause long-term damage to the visual cortex. Even if this is not the case, there is no doubt some people have suffered discomfort watching 3-D movies. As a result, health issues figure prominently within the standards groups, especially those representing operators such as WBU-ISOG (World Broadcasting Unions-International Satellite Operators Group), because they are the ones serving customers directly.

In practice, WBU-ISOG and other standards bodies have concluded that more research is required on the impact of 3-D on both short-term viewing comfort and long-term ocular health before any decisions can be made on standards. It is already accepted, however, that not all people will want to watch in 3-D, even when technology improves and glassesless viewing becomes possible with larger screens. Glassesless viewing is currently confined to small screens such as smart phones, with large screens being too dependent on the head position to make stereoscopic viewing work from all angles. To make 3-D operate satisfactorily without glasses on a large screen, some form of multiview display is needed to focus the two beams accurately across the field of version. Multiview displays are already used by digital signage displays, but those can get away with lower quality because people just glimpse at them from a distance. With flat-screen TV displays, such technology suffers from dead zones as the viewer moves around the screen. Solving this would require a greater number of viewers to make the dead zones disappear, but this would increase the bandwidth even further, because each view is generated across the whole field and yields almost as many pixels as a current large-screen display. Here, too, further research is needed to determine the optimum number of views and the bandwidth required before standards can be set.

This means that, for the moment, 3-D will most likely be an option just for some types of programming and will not be rolled out across the board like HD, currently in its 720p or 1080i flavors, but almost certainly 1080p over the coming decade. Indeed, standards bodies have been discussing what form of HD works best for the twin 3-D streams, with broad agreement that 3-D on large screens is particularly dependent on high resolution and that it must move toward dual 1080p.

That, however, would consume four times the bandwidth of current 720p or 1080i HD services, and so it is not feasible yet, even if the content and technology were in place. Therefore, it is a choice between 1080i and 720p at the moment, and it has been found that 720p works best for well 3-D. Tests by Canadian satellite broadcast equipment company International Datacasting and others have consistently found that interlacing and 3-D do not mix well and confuse the human brain for reasons not yet fully understood. Because interlacing seems to amplify the general viewing problems presented by 3-D on a large screen, it is likely that standards bodies will be recommending 720p, stepping up to 1080p as soon as economically viable.

This leads to the bandwidth issue, which will constrain 3-D services for all four principal kinds of TV transmission: satellite, cable, digital terrestrial and IPTV. Ironically, it may be less of an issue for mobile TV because the bandwidth required will be so much less. For satellite broadcasting, 3-D service providers will have to acquire even more bandwidth, increasing both initial provisioning and recurring costs, while for both cable and IPTV providers, it will accelerate the need to push fiber deeper and to the home to obtain the required access bandwidth. It will also put pressure on core network capacity and accelerate the provision of content distribution networks that push the video closer to the points of consumption.

As for terrestrial broadcasters, available bandwidth will often prohibit significant 3-D, or even HD, deployment, until they have upgraded to DVB-T2, services, which are now available in several European countries including the UK, Sweden, Finland and Italy, with pilots being conducted in parts of Germany.

Apart from bandwidth, resolution and multiview technology, there is a lot of time spent debating subjective issues concerning likely demand for 3-D and the type of programming for which it is most suitable. This could be a particular issue for news or nature programming in which the content can vary between narrow aspect views of people speaking or close-ups of animals and panoramic location shots, which may be less suitable for 3-D.

There is also debate about how best to film 3-D, because quality is perhaps more dependent on the use of the appropriate camera techniques. For example, so called “toe-in” shooting, in which two cameras are focused on a single, main object on the screen, such as a face, has been tried because it improves the image concerned, but it tends to skew the background. Although not strictly a standards issue, this has been discussed at meetings and proved controversial, but with a consensus emerging that either it should not be used at all or sparingly for scenes with very little background.

Then there are the political issues, with a split between TV set makers, which have tended to dominate 3-D evolution so far, and broadcasters/operators, which have to deliver services to consumers. The equipment makers naturally want to exploit a new technology that enables them to sell expensive hardware, but it is operators who may end up getting the blame when consumers realize that the service is not as good as they hoped. For this reason, broadcasters are trying to seize some control of the 3-D discussion back from the equipment industry.

Part of this direction concerns interoperability, which often tends to be given higher priority in Europe given the large number of countries and varying transmission and regulatory standards. There is a feeling that 3-D will only succeed ultimately if there is convergence around a single set of standards. But if the quality issues can be resolved, and 3-D becomes easier on the eye as well as visually exciting, then it may be the game changer for TV that some of its advocates have been hoping for.



Comments
Post New Comment
If you are already a member, or would like to receive email alerts as new comments are
made, please login or register.

Enter the code shown above:

(Note: If you cannot read the numbers in the above
image, reload the page to generate a new one.)

No Comments Found




Thursday 10:05 AM
NAB Requests Expedited Review of Spectrum Auction Lawsuit
“Broadcasters assigned to new channels following the auction could be forced to accept reductions in their coverage area and population served, with no practical remedy.” ~NAB


 
Featured Articles
Discover TV Technology