German research institute Fraunhofer IIS has announced a new surround sound codec that operates at stereo coding rates, writes Kevin Hilton.
MPEG Surround (MPS) was standardised two years ago and is designed to provide current mono or stereo music download and broadcast services with 5.1 capability at bitrates from 64kbps to 320kbps. Consumers will be able to use existing set-top boxes to receive these expanded audio signals.
Practical demonstrations of the codec were given during IBC2010. Fraunhofer spokesman Matthias Rose described MPS as a parametric system, which takes 5.1 inputs and converts them into a stereo down-mix. This is mixed with parameters describing the surround information.
"Any audio codec can be used to compress the 5.1 material, for example AAC," Rose explained. "Then you transmit a stereo file with some additional parameters. If the consumer has only a stereo playback system then stereo will be reproduced but if he has MPS the parameters will be used to recreate the surround image."
Rose says the way MPS works will be of particular interest to internet radio operators, as well as those in general broadcasting. "That's why we have spent a lot of effort over the last one to two years introducing MPS into different broadcast standards, including DVB, ISDB [Integrated Services Digital Broadcasting] in Japan, World DMB and DRM," he commented.
Trails are now underway at Antenne Bayern, the largest private radio network in Germany. The broadcaster is transmitting MPS encoded programming 24-hours a day over terrestrial links. "Antenne Bayern is one of our partners in trials to demonstrate that MPS is a technology that is product ready and can be used in any broadcast system," says Rose.
As well as broadcasters Fraunhofer is working with equipment manufacturers to ensure that receivers capable of picking up MPS come on the market in good time. The car sector is regarded as particularly important and the institute is in discussion with auto companies to install this new technology. "The car is the ideal environment for playing back surround sound," Rose commented.
Fraunhofer demonstrated MPS during IBC alongside the Diveemo DRM-based video technology, which had its official launch on the Thomson stand.