Coding Technologies (Stockholm, Sweden and Nuremberg, Germany), a spin-off of the Fraunhofer Institute (Erlangen, Germany), developed MP3Pro under contract by Thomson Multimedia SA (Paris) and Fraunhofer.

Downloads of the demo MP3Pro player/encoder software can be found at two Thomson Multimedia Web sites: www.thomson-multimedia.com and www.rca.com, as well as from the Coding Technologies site.

Thomson Multimedia plans to license the codec, which consists of an MP3 core with a technology called Spectral Band Replication (SBR) wrapped around it, to semiconductor manufacturers, jukebox software providers, digital audio portable device and computer companies. A Thomson Multimedia spokesman said deals would be announced soon.

SBR works by enhancing the efficiency of MP3 and other perceptual audio codecs by approximately 30 percent in the medium- to low-bit-rate range.

"SBR is a very efficient way to code high frequencies," explained Coding Technologies president and chief executive officer Martin Dietz.

The improved coding efficiency means MP3Pro yields twice the playback time with the same amount of memory and better-sounding audio than MP3 files even at bit rates under 64 kbits/second.

For instance, MP3 sound quality is high when it is compressed at 128 kbits/s, but when the compression bit rate is lowered to 64 kbits/s and below, MP3 files sound muddy. because they are missing high-frequency components. That's inherent in the design of the MP3 codec: When the compression bit rate is lowered, the codec opts for limited bandwidth rather than the introduction of coding artifacts.

When SBR is added to the MP3 core, however, it regenerates the high-frequency components so that the bandwidth is higher and the file compares in audio quality to a conventional MP3, at a bit rate of greater than 100 kbits/s in stereo.

Dietz said SBR accomplishes this through digital signal processing, performed before the file is fed into the MP3 encoder and after it is processed in the decoder, as well as via transmission of information in the MP3 bit stream.

Mp3PRO is compatible with Microsoft's Windows 9x, 2000, NT and Millennium; it encodes .wav files into MP3Pro files at 64 kbits/s and plays back all MP3 and MP3Pro files.

Libraries for Apple's Mac OS 9 and for the Linux operating system will be added later this year.

While existing digital audio player devices do not yet support MP3Pro, most will still be able to play MP3Pro files, thought the files will be played as MP3s, without the new codec's enhancements. The only requirement is that the players also must support sampling rates of 16, 22.5, 24, 32, 44.1 and 48 kHz. Most software players support these rates, but not all portable and CD/DVD players do.

To support MP3Pro in digital audio players, firmware either in software or programmable ROM must be added to a chip. In the case of a player with a programmable DSP, the codec could be downloaded.

Whether chipmakers, digital audio player manufacturers and others design-in support for MP3Pro will depend on how successfully the codec competes with MP3, Windows Media Audio and other codecs and whether it receives the backing of the music industry. If the music industry uses the codec, then player manufactures will have to include it. Obviously, security will be a factor in the record labels' decisions.

Currently, MP3Pro does not feature any security or digital rights management (DRM) technology.

A Thomson Multimedia spokesman said the company doesn't think that not having a security or digital rights management system in MP3Pro will prevent it from becoming a popular audio codec.

"Consumers haven't been clamoring for DRM technology," he noted.

None of the major record labels plans to adopt the MP3Pro codec yet, but the spokesman said discussions are ongoing.

Coding Technologies' Dietz said if it's needed, an encryption layer could be added to the MP3Pro codec to make it secure.

He said the same could be done with MP3. But he noted that the problem with MP3 and earning the acceptance of the record labels is that the codec is associated with piracy. In addition, he said that there are already so many insecure MP3 bit streams available that having a few secure versions of MP3 might not make a difference.

The same could become true of MP3Pro one day, if too many insecure versions of the codec are available.