The BBC is to give its first public demonstration of HDTV as part of Saturday's Live 8 event.

Crowds gathered at the corporation's 'Big Screen' near Cardiff Castle will be able to enjoy BBC One's coverage of the all-star gig in high definition quality on a 17ft screen. The trial relay features 1080 lines and 50 interlaced frames a second, with a display screen of 1920x1080 pixels.

"This is a great opportunity for the BBC to test its delivery of HDTV at a big public event," said John Varney, BBC Chief Technology Officer. "Who knows? It may prove to be the shape of things to come."

The BBC intends for all of its programming to be produced to HDTV standard by 2010.