Video Breakthroughs

This paper explores the opportunities and challenges of supplementing television broadcast channels with additional content using IP delivery. It looks at the way in which the additional material could be resynchronised with the broadcast content and what level of accuracy is required by different types of material.

It focuses on the use case of an alternative soundtrack to provide improved intelligibility for viewers who have difficulty understanding speech when presented with background sound. It then goes on to describe our demonstration system and discusses the opportunities for further research into hybrid delivery and the way it could enable a richer broadcasting landscape.

Blog post : http://www.bbc.co.uk/blogs/researchanddevelopment/2010/11/synchronising-broadcast-and-ip.shtml

In that earlier blog post, I mention that technologies exist that are already being used to synchronise media on mobile devices to television programmes, such as audio fingerprinting and watermarking, video fingerprinting and watermarking and delivering synchronisation information via the Internet. The advantage of all these solutions is that they require no modifications to the set-top box or television. A common disadvantage is that content on other devices can only follow what happens on the television, and not vice-versa. In the longer term, we believe that a technology like Universal Control offers very significant advantages in this regard, but we recently took advantage of an opportunity to work with colleagues from across the BBC to investigate some of these existing methods of synchronisation, to see what kinds of "dual screen" experience might be possible today.

Our most significant contribution to the work has been an API to permit the developers of dual-screen applications to ignore the details of specific synchronisation technologies. It provides a standard interface, behind which any number of information sources may be working (individually or together) to provide the application with information about what programme the user is watching (if any), and what events are occurring in it that might trigger synchronised behaviour. This approach helps the BBC avoid getting locked into using the technology of a specific supplier, and helps "future-proof" applications: as new synchronisation technologies become available, little or no extra effort is likely to be required for existing applications to be able to make use of them. (Of course, one of the sources of information could be a Universal Control server on the set-top box...)

While many people already play around with their mobile phones or tablets while watching TV, perhaps following discussion about the show on Twitter, the BBC is doing some fascinating R&D work which could help mobile devices become more useful ‘second screens’ for television.

The Orchestrated Media project is working to display relevant, supporting content for the show you’re watching, in sync with the show. So, a documentary on dinosaurs may display information about the beasts currently depicted on screen, or a news broadcast could display detailed information about the current story without you having to look for it.

The BBC’s Jerry Kramskoy has told us a little more about the technology behind Orchestrated Media: “Audio watermarking works by striping the audio in the content, which is broadcast. The companion device listens out for this to sync up. So this is a one-way flow of sync … the TV is the master, the companion the slave … always. This means the companion cannot control the TV.

“To make the TV content follow the companion device content, as in the Autumnwatch video on my blog, requires s/w in the TV that the companion talks to, to allow the companion to be the master when it wants. This latter scenario is whate we refer to as symmetric sync, and the TV and companion are in a peer-to-peer relationship, whereas the previous one-way sync we refer to as asymmetric sync, where the TV and companion are in a mster-slave relationship. Standardisation is necessary around what and how features are exposed by the TV to support symmetric sync”

BBC R&D has developed a universal control system API that opens up a wide range of possibilities for interacting with your TV across multiple devices.

The technology allows a network-connected device, be it a smartphone, laptop or toy Dalek, to talk via the home network to a set-top box that runs a particular piece of software. By doing this, a connected device can obtain the information it needs to synchronise things to the box, such as images or audio. The API (application programming interface) that the software implements is called Universal Control.