The digital form of multi-channel audio data (e.g. 5.1-channel) before it is decoded into its various channels.

Promoted by a group of companies led by Sony, the Blu-ray Disc (BD) is a new-generation, high-capacity optical disc format. Utilizing a shorter-wavelength blue laser, the BD offers a massive storage capacity of 25GB on a single-layer disc and 50GB on a double-layer disc, five times the amount of current DVDs.