By Jon Iverson & Wes Phillips

January 09, 2004 — The format battle over what goes into your audio player's disc drawer could soon be rendered moot. Forget SACD and DVD-Audio: it's the format war taking place on your desktop that may determine the real future of audio. And, believe it or not, audiophiles might win, too.

We sat down with David Caulton, the group product manager for Microsoft's Windows Digital Media Division, to discover what was behind the Windows Media Audio logos that are starting to pop up on consumer electronics gear (such as the new Pioneer Elite multichannel receivers), and also learn how the future for high resolution audio might play out.

Microsoft's Windows Media platform contains the Windows Media Audio (WMA) encoder and decoder needed to play typical MP3 audio files, not to mention the highly compressed WMA files available for download from music services such as the relaunched Napster. It can do this not only on your Windows computer hooked up to the internet, but also on any device that has teh software built in, such as those new Elite receivers.

The latest version of the platform, Series 9, also contains Windows Media Audio Pro, which can encode and decode up to 8 channels of 96kHz/24-bit PCM audio. Here's the interesting part: it can do this using either an adjustable lossy compression scheme optimized for the 96/24 data, or encode/decode the signal using a lossless compression codec that still cuts the storage space needed in half by using a proprietary scheme similar in function to the MLP "lossless packing" process used with DVD-Audio.

A 96/24 audio signal can therefore be compressed using a fixed or variable bit rate encoder at a variety of rates that render the file small enough to enable consumers to download over the Internet, and then be reconstituted as a 96/24 PCM file in the player—even if the file is a 5.1 or 7.1 mix.

To prove this last point, Caulton fired up the WMA Pro player and clicked on a downloaded 96/24 5.1 mix of Pink Floyd's "Money," which was reproduced with surprising fidelity on the modest demonstration system.

Microsoft now faces the chicken and egg audio problem: without much WMA pro software out there yet, how do you get the hardware manufacturers to start including the platform in their new products? And without the hardware, why would record labels release music in the format?

To prime the pump, Caulton says that Microsoft is starting to work with many of the chip manufacturers that supply the DSPs for consumer electronics products like preamps, receivers, and disc players. "Our mission is to make sure WMA Pro is included in all classes of devices" says Caulton, in an effort to provide "play anywhere" portability.

And what about those pesky Digital Rights Management (DRM) restrictions that legitimate downloaded audio files have these days? Caulton suggests that "those are issues to be worked out between the record labels and the consumers. We just supply the DRM tools, but they decide which ones to use and how to use them." He adds that he hopes content providers can find a middle ground that make consumers happy, a solution that has so far eluded DVD-Audio and SACD. He noted, "it's nice that the formats have 5.1 and higher resolution audio, but the mass market prioritizes convenience."

Looking towards the relatively near future, Caulton envisions downloadable audio files being made available in a variety of resolutions including 96/24 5.1. He also sees 96/24 WMA discs eventually being released, thus closing the circle with one format to rule them all—both on or off the desktop.

There's only one problem. Apple and several others have their own AAC-based formats that are incompatible with WMA and will likely begin to scale to higher audio resolutions themselves. We'll have more on that in a future report. Caulton notes that WMA Pro includes decoding for MPEG4, which itself includes provisions for AAC. It's just the way that Apple and others are using AAC that won't work with the Windows Media platform for now. Caulton also cautions that WMA Pro is not currently compatible with DVD-Audio or SACD data, since the formats use different schemes for encoding and compressing data. But who knows? After the online format wars subside, even that could change.