Dolby adds High-Efficiency AAC to MPEG 4 patent pool
By Tony Smith
Published Tuesday 20th July 2004 08:53 GMT
Dolby's licensing division is to make it easier for manufacturers to licence the more advanced form of the Apple iPod-friendly audio format, AAC.
Via Licensing yesterday said it had partnered with the MPEG 4 Audio Licensing Committee to simplify access to key intellectual property behind High-Efficiency AAC - aka AAC Plus. HE AAC-related patents will be added to the broader MPEG 4 audio patent pool to provide one-off licensing.
The move, they claim, will make it easier and - crucially - cheaper for companies to ship products that support HE AAC.
That's not an indication of the iPod-led popularity of AAC. Rather it's the result of the DVD Forum's decision to mandate the use of HE AAC as the audio format for DVD 'ROM zones' - a new area that can be added to DVDs that provides computer-compatible content. HE AAC is also being deployed as the basis for audio streaming across 3G mobile phone networks.
By contrast, Apple uses Low-Complexity AAC files. And in any case, its proprietary FairPlay DRM technology is not (yet) available for licensing, so the Via/MPEG 4 ALC's move isn't going to open the floodgates to true iPod clones.
HE AAC uses a technique called Spectral Band Replication (SBR), which essentially provides room for higher levels of compression without losing sound quality. HE AAC encodes high-frequency sounds with SBR and low frequencies with regular AAC. HE AAC was developed by Dolby, Coding Technologies, AT&T, Sony, Philips, NEC and the Fraunhofer Institute, one of the co-developers of MP3. ®
