DVD-Audio (commonly abbreviated as DVD-A) is a digital format for delivering high-fidelity audio content on a DVD. DVD-Audio is not intended to be a video delivery format and is not the same as video DVDs containing concert films or music videos. Since its inception DVD-A has been in a format war with Super Audio CD (SACD), another format for delivering high-fidelity audio content. Here at Hi-Res Edition we embrace this format, although they were never widely accepted by consumers.
Offering many possible configurations of audio channels, ranging from single-channel (mono) to 5.1-channel (surround sound), at various sampling frequencies and sample rates, compared to the Compact Disc. The much higher capacity DVD format enables the inclusion of either; considerably more music (with respect to total running time and quantity of songs) or, far higher audio quality, reflected by higher linear sampling rates and higher bit-per-sample resolution, and/or additional channels for surround sound.
However, due to limitations in the capacity of DVD's, multi-channel releases are only available at a maximum of a 24 bit depth and 96 kHz sampling frequency. These programs are not truly lossless, although carry a much superior sound quality to the compact disc. Yet, lossless material is still available on DVD-A's when offered as a stereo LPCM program with a 24 bit depth and up to 192 kHz sampling frequency.
One advantage that DVD-A's maintain over SACD's is the ability to include video content and a menu system to include extras and alternate mixes. The Blu-ray Disc supersedes both of these formats by providing lossless audio and high-definition video on the same disc.
For more information on DVD-Audio, please see the DVD-Audio Disc Article on Wikipedia