At its European Conference held October 30 in Paris, the DVD Forum agreed to extend the DVD-Audio specification to include support for an additional layer containing CD-audio content. That means, in theory, that once the new spec is completed record labels will be able release DVD-Audio titles that also play in standard CD players, a la the "hybrid" disc promoted by the rival SACD format... SACD has trumpeted its hybrid format to great effect, and scored a coup by getting a slew of Rolling Stones reissues to ship into stores with both a CD layer and an SACD layer. But some observers say DVD-Audio may not enjoy the same near-universal playability boasted by SACD.

"Prototype discs will have to be tested on a wide range of existing DVD-Video, DVD-Audio/Video and CD players to ensure there are no playability problems," cautions UK-based marketing consultancy...