The DVD Forum's decision to include Dolby Digital Plus and MLP Lossless as mandatory audio standards for HD DVD ensures that the audio quality of HD DVD will be just as compelling as its video quality.
Dolby Digital Plus offers bit-rate and channel extendibility and is an extension of the popular Dolby Digital format, which is the audio standard for DVD-Video worldwide and North American high-definition television (HDTV). The DVD Forum's selection of Dolby Digital Plus as a mandatory audio standard assures future compatibility of HD DVD software media and playback devices with the more than 39 million A/V receivers equipped with Dolby Digital in homes today. Additionally, DVD-Video software titles will retain full audio compatibility with next-generation HD DVD-Video players.
For instances where higher bit rates can be allocated for audio playback, such as HD DVD, Dolby Digital Plus delivers audio performance from a perceptual coding process. Dolby Digital Plus is designed to offer discrete channel coverage beyond the current 5.1 standard.
Dolby Digital Plus offers coding efficiencies for systems where bandwidth is at a premium or limited, such as next-generation cable, broadcast, and satellite systems. In anticipation of future packaged media business models and format flexibility, Dolby Digital Plus' efficiency will also enable simultaneous streaming of audio content and software playback. This capability would enable consumers to watch a movie while listening to artists' or directors' commentary streamed directly from the studio website, for example.
MLP Lossless technology, licensed by Dolby Laboratories, has also been selected as mandatory audio standard of the HD DVD by the DVD Forum. MLP Lossless reproduces the original performance, including elements that may have been previously lost or masked in CD playback. Because it delivers audio fidelity without compromising picture quality or video bit rates, MLP Lossless complements Dolby Digital Plus. The DVD Forum's selection also ensures that consumers with HD DVD players will be able to play DVD-Audio discs.
The core audio technology behind multichannel DVD-Audio, MLP Lossless, enables content providers to encode multiple channels of 24-bit/96 kHz surround sound or 24-bit/192 kHz stereo content onto a DVD. Playback of content encoded in MLP Lossless is identical to the studio master—nothing is lost during the encoding/decoding process.