NAB: New 5.1 Extension Means Better Compression

Dolby Laboratories have announced an extension to their Dolby 5.1 codec, called Dolby Digital Plus. The codec extension is of particular interest to television broadcasters because of the efficiency of its compression: if audio tracks take up less room, then it leaves more bandwidth for more channels.

Broadcasters are keen to deliver more channels to customers – particularly when they’re charging them – but need to keep picture quality up to, or even better than, current standards.The existing DD codec supports but rates from 320Kbps to 640Kbps for 5.1 audio – yet this new extension will reproduce 5.1-channel sound down to 192Kbps. Dolby Digital Plus has a new top end to – up to 6Mbps, which will no doubt be handy in the future.

Importantly, Digital Plus is backwardly-compatible with previous versions of the 5.1 codec.

Dolby have already come up with an interesting application for the new codec – a DVD could access a studio’s website and stream a live director’s commentary, or other interactive content, through the viewer’s TV.

Dolby Digital on Digital Plus

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Fraser Lovatt

Fraser Lovatt has spent the last fifteen years working in publishing, TV and the Internet in various capacities, and believes that they will be seperate platforms for at least a while yet. His main interests at the moment are exploring where Linux is taking home entertainment and how technology is conferring technical skills on more and more people. Fraser Lovatt was born in the same year that 2001: A Space Odyssey was delighting and confusing people in the cinemas, and developed a lifelong love of technology as soon as he realised that things could be taken apart, sometimes put back together again, but mostly left in bits or made into something the original designer hadn't quite planned upon. At school he was definitely in the ZX Spectrum/Magpie/BMX camp, rather than the BBC Micro/Blue Peter/well-behaved group. This is all deeply ironic as he later went on to spend nine years working at the BBC. After a few years of working as a bookseller in Scotland, ("Back when it was actually a skilled profession" he'll tell anyone still listening), he moved to England for reasons he can't quite explain adequately to himself. After a couple of publishing jobs punctuated by sporadic bursts of travelling and photography came the aforementioned nine years at the BBC where he specialised in internet technologies and video. These days his primary interests are Java, Linux, videogames and pies - and if they're not candidates for convergence, then what is?