Via Licensing Corporation today announced the launch of a joint patent licensing program for MPEG-4 Scalable to Lossless Coding (SLS) also known as "HD-AAC". SLS is an audio compression technology which extends MPEG-4 AAC (Advanced Audio Coding). With MPEG-4 SLS, a lossless data compressed audio file played through an HD-AAC decoder produces results that are bit-for-bit identical and of equivalent quality to the original source material. Playing that same audio file through a standard AAC decoder delivers the same quality and performance it would if originally encoded in AAC.

MPEG-4 SLS has been branded "HD-AAC" by Fraunhofer IIS, the German research institute famous for developing mp3, and a co-developer of the SLS technology along with the Agency for Science, Technology, and Research’s (A*STAR) Institute for Infocomm Research.

SLS is implemented as an enhancement layer to AAC where upward scalability (towards full lossless compression) is achieved by dedicating varying amounts of data to the SLS enhancement. The average compression ratio of SLS is equal or superior to many existing lossless audio compression schemes that do not offer backward compatibility. In addition, SLS features full multi-channel capabilities.

Consumer applications for SLS include the ability to manage and store a music library that simultaneously supports lossless playback on high quality audio equipment in the home, as well as playback on portable media players and mobile phones that support AAC.

Licensors offering their essential SLS patents through the new licensing program currently include A*STAR Exploit Technologies Pte Ltd (Singapore), Fraunhofer IIS (Germany), and Nippon Telegraph and Telephone Corporation (Japan).

For additional information and a presentation of the SLS licensing fees visit www.vialicensing.com