Anthony Rose, the chief technology officer of YouView gave some further insights into the planned platform in his keynote at the Streaming Media Europe conference in London. One of the problems that YouView has faced is that no-one seems to understand how it will work, an issue intensified until recently by lack of technical detail. “Almost everyone knows of YouView and Project Canvas but it actually turns out that very few people know very much about what it is,” he said. So what exactly is YouView, beyond a blending of broadcast and broadband?

“It’s an open platform,” maintained Anthony Rose. At a technical level it may be more open than most and as an advocate of open source software, he is certainly open to talking about the technology. He approaches connected television from an internet perspective, which may be no bad thing. His experience with the iPlayer at the BBC, where he is still based, has clearly been influential. If anything, he is overly optimistic about the possibility of creating a truly open platform in a competitive commercial market.

The YouView consortium may be a well-funded initiative to be run on a cost-recovery basis, but it is unclear how anyone else will make money from the platform. It seems that commercial models, payment gateways, or targeted advertising are out of scope. Sensibly perhaps, as they would only draw the fire of critics of the former Project Canvas, of which there are many.

Curiously, for all the open ideology, the YouView user interface will be based on Flash, a published but proprietary standard from Adobe. YouView is not alone in this. Google TV will also support Flash but Apple and others are less favourable to the Adobe technology, advocating instead open, albeit still evolving web standards like HTML 5 and CSS 3.

The architecture that Anthony Rose describes is based on what he calls a D-bus or application programming interface.

Below this, manufacturers can innovate. “Anyone can make a box and they don’t need to call it a YouView box.”

Above will be a platform image of managed code, be it Flash, Python or JavaScript, which will be deployed across all YouView boxes. “For us that addresses the key challenge. We wanted our UI to flourish on a whole range of different devices including those in years to come which have got lots more power.”

Whether this will allow manufacturers to differentiate their products sufficiently is open to question, since any features and functions will need to manifest themselves in the user experience.

For third-party services, there will be applications, written in flash, or in due course HTML, both technologies well-known to web developers, rather than obscure interactive television middleware languages.

Applications can be listed in an app portal, subject to conforming to a minimum set of requirements. Programming providers can also supply metadata to describe their media, to be listed in searches.

“That’s the way,” he said “we break out of a world where people perceive it is dominated by the EPG”. He said it was crazy that EPG slots should be allocated in the order in which broadcasters received their transmission licences. Not that one can imagine the shareholders in YouView giving up their top five positions.

However, there appears to be a genuine attempt to address the limitations of some current connected television propositions and make it easier for third-party providers to promote and deliver programming to YouView devices. That said, this will generally be within a framework orchestrated by the main terrestrial television channels, which will no doubt continue to dominate viewing.

As a vision of the future, Anthony Rose said the 2012 Olympics will be big. “For YouView and the BBC there’s a great opportunity for things coming together.” He said there will be between 20 to 40 live channels available providing over 5,000 hours of coverage.

Whether it is sensible to promote a platform on the possibilities of a few weeks of coverage, it demonstrates the public service thinking that still lies behind YouView, still very much dominated by the BBC. It is an example, perhaps deliberately, untroubled by commercial issues that are likely to present the main challenges and regulatory problems for the platform.

At a technical level, the use of multicast to enable the cost-effective delivery of live channels may be the most significant contribution of the YouView platform. “We think multicast is a key enabler that YouView provides,” said Anthony Rose. “Of course multicast has been around for yonks but it turns out that only about 5% of the internet in the UK is multicast enabled.”

That will change, as YouView partners BT and TalkTalk are going to enable multicast on their networks and create their own multicast channels. Virgin Media already has multicast enabled. The latest version of Flash also provides multicast capability. “So I think you’ll see the flowering of multicast.” Indeed, providing a reason for BT to support multicast may be single most significant contribution YouView will make.

In addition to proprietary RTMP and RTMPE streaming, there will also be http chunked adaptive bitrate delivery, using MPEG-2 transport streams. When the various standards bodies work out what it will be there will be MPEG-4 adaptive bitrate as well. Asked about open video codecs, he said they were not being considered at the moment as they are not currently hardware accelerated in system on chip processors.

For content protection, YouView will support Marlin Broadband digital rights management and MS3 simple secure streaming. “Marlin MS3 is about as open they come,” notes Anthony Rose. “Our deal with Intertrust means it is free for a content provider to use Marlin MS3.” YouView plans to provide sample reference code for packaging and licence serving. “We’re going to do our best to try and help people get their content onto YouView as easily as possible.”

As far as payment goes, YouView will be open to multiple billing mechanisms. “It’s an open platform,” said the YouView chief technology officer. “Whatever you do on the internet, you can do here. We don’t want to kingmake any one payment service provider.” Instead, YouView plans to provide an infrastructure that will support different payment gateways. So if a viewer is on a BT network they could opt to charge payments to their broadband account, or they could use a separate service provider like PayPal.

From a technical perspective, YouView may be a well-intentioned attempt to build an open platform. It sounds superficially persuasive, but whether it will genuinely open up new opportunities, or simply maintain the interests of its stakeholders, remains open to question. The key question is not the degree to which YouView is an open platform, but how open its shareholders are to alternative distribution channels.