HD Disc Format Orgs Sound Off On Sound

We have heard the soundtrack of the High Definition future on DVD, and it's compatible with the jillion1 or so digital surround sound receivers currently delighting home theater owners around the globe - or so says Dolby Laboratories and DTS. In separate recent announcements, each company proudly touted the fact that their audio technologies have been selected as a mandatory part of both the High-Definition Digital Versatile Disc (HD DVD) and the Blu-ray Disc high-definition video disc formats. The two rival disc formats are locked in a good-versus-evil, battle-to-the-death struggle to convince studios, manufacturers, consumers, and anyone else who will listen that their format makes the most sense (and cents) for the future of packaged optical media. Although most people immediately think video when they hear about High Definition on disc, the announcement of mandatory audio standards is an excellent reminder to all concerned that audio quality is just as important as video clarity.


The DVD Forum, a specifications-setting organization for the DVD format, has selected Dolby Digital Plus and MLP Lossless technology as mandatory audio formats for HD DVD. Dolby Digital Plus is an extension of the Dolby Digital format we've all come to know and love thanks to DVDs and North American HDTV broadcasts. Originally unveiled earlier this year to the National Association of Broadcasters (NAB) (the people responsible for making sure the latest reality TV show makes its inane way to your living room), Dolby Digital Plus is designed to add more versatility and capabilities while maintaining backwards compatibility with all the Dolby Digital 5.1 systems in use today. On an HD DVD, where higher bit rates can be allocated for audio playback, Dolby maintains that Dolby Digital Plus will deliver "the highest quality audio performance possible" due to a "highly sophisticated perceptual coding process." Dolby Digital Plus will also be able to offer more discrete channels than the current 5.1 standard.

The DVD Forum also selected MLP Lossless technology, developed by Meridian Audio and licensed by Dolby Laboratories, as a mandatory audio standard of the HD DVD. MLP Lossless is the core audio technology behind multi-channel DVD-Audio discs where it enables encoding of multiple channels of 24-bit/96kHz surround sound or 24-bit/192kHz stereo music.

The DTS Coherent Acoustics coding system wasn't forgotten by the DVD Forum, either. In addition to including DTS' core technology as a mandatory audio technology for the HD DVD, they also selected DTS' extension technologies as optional. The extension technologies, including DTS-ES and DTS 96/24 and identified collectively as DTS++, encompass higher data rates, lossless operation, and additional channels. DTS asserts that "both the mandatory DTS core technology, as well as optional higher sampling rates such as DTS 96/24 and additional channels up to 7.1...offer DTS' premium audio quality to consumers while retaining compatibility with all existing DTS decoders."

Blu-ray Disc

The announced audio standards for the Blu-ray Disc format, too. Dolby Digital is now a mandatory audio standard for the Blu-ray disc. DTS' core technology also got the nod, along with DTS++ extensions being named as optional features. DTS claims that this makes DTS++ "the only lossless audio technology selected for both formats."

Of course, neither format is officially here; and unless your crystal ball is a whole lot better than ours, it's anybody's guess as to which shiny disc will eventually gain mass market acceptance. The one thing we do know, however, is that if either one of the proposed formats makes it to the big leagues, it'll sound just fine.

1Actually, Dolby Laboratories claims that there are more than 39,000,000 (that's 39 million) A/V receivers equipped with Dolby Digital. DTS, to quote a figure that includes more than just A/V receivers, states that there are over 280 million DTS-licensed consumer electronics products worldwide.