BBC launches open-source video technology

The codec, called Dirac (after physicist Paul Dirac), is still in alpha but by the time it goes to beta in autumn 2005, say its developers, there is a good chance that it will be as good, if not better, than anything else out there.

Lead developer Dr Thomas Davies, who founded the project three years ago, has MPEG2, Windows Media Player in his sights.

Davies was keen to stress that he is not seeking to create a product, but rather a tool that other developers can use to build their own software.

"It is an entirely general-purpose code," he said. The technologies used are, he said, suitable for everything from low resolution mobile phone screens to high definition television and even cinema, because we have used wavelet technology and that is scalable. "You could use it for desktop video production, you could use it for streaming, or you could use it for movies -- anyplace where you need compression."

Davies plans to release a new set of coding tools over the coming year.

By the time the beta launches, in autumn 2005, Davies wants the software to be able to decode standard definition pictures in real time. "By then we should have all the decoding tools, and it should be plugged into a number of different players."

The corporation has gone to great lengths to avoid any patent problems, and has used tried and tested techniques that have prior art. "We are reviewing the literature and will code round the problems as they arise."

To protect the software and the techniques used to develop it, the BBC has taken out its own defensive patents, said Davies, and is releasing the software under the Mozilla licence to ensure "that those patents are licensed for free, irrevocably, for ever."

The terms of the licence mean that Dirac could be used in open source software, said Davies, or in proprietary software in such a way that the company producing that software would not have to divulge their source code.

Dirac is one just one of a number of open-source software tools being developed by the BBC. The corporation is also working on the material exchange format (MXF), which will be used for exchanging multimedia data. "We intend to wrap Dirac inside MXF with an audio stream plus synchronisation data and metadata," he added.