After digitalisation and storage, broadband is the third driver of the television revolution that promises to cause rapid growth in viewing choice - and hence in the need for television metadata.
Television programmes and television-like multimedia content and services will be turning up on many more screens than television screens (including PCs, mobile phones, games consoles, PDAs and new home entertainment devices) and will get there via many more routes (including cable, satellite and digital television networks, telecommunications networks of all kinds and removable media such as DVDs).
As is the case with digitalisation of television, the MPEG series of standards is set to play a leading role in the world of widely available multimedia. The MPEG-4 standard is the first multimedia standard designed from the bottom up to support the distribution of rich, reusable interactive multimedia content via the widest possible range of distribution networks and terminals.
To address the pressing need for improved multimedia metadata that will result from the widespread implementation of MPEG-2 and MPEG-4, the Moving Picture Coding Experts Group is close to finalising MPEG-7 - its standard in the area of what it refers to as "multimedia description". The explicit aim established at the outset was not to meet the needs of any particular application area (such as digital television or personal digital recorders), but "rather, the elements that MPEG-7 standardises shall support as broad a range of applications as possible". It will, therefore, be especially important for multi-purpose multimedia content that, for example, could be distributed as a television programme, a broadband webcast and on DVD.
Fortunately there has, from the outset, been overlapping membership and close co-operation between the TV-Anytime Forum and MPEG. The TV-A metadata specification and XML Schema are based on MPEG-7's Description Definition Language (DDL) and its Description Schemes (DSs) and Descriptors (Ds) and every effort has been made to ensure compatibility between the two standards. MPEG-7 has itself, in turn, been influenced by TV-A developments.