MPEG Surround® is a feature-rich open standard coding technology for multichannel audio signals. Operating on top of any core audio codec – including AAC, HE-AAC and MPEG Layer 2 – the system provides a comprehensive feature set, including highest surround and stereo audio quality, bit rates currently used for the encoding of stereo signals, full backward compatibility to stereo equipment, wide scalability in terms of the surround image description bit rate, and virtualized binaural multichannel sound reproduction capability for stereo headphones.
High quality multichannel audio (for example for 5.1, 7.1 or 3D audio systems)
Multichannel support at stereo bit rates
Compatible with existing stereo devices
Mobile surround reproduction over stereo earphones
Cost-effective way to expand any stereo infrastructure for multichannel usage
MPEG Surround technology extends any existing audio distribution chain from mono or stereo towards high quality, multichannel audio while remaining fully compatible with existing receivers. It also enables the creation of new surround services that are not possible with legacy formats.
Broadcast services and devices
Internet broadcasting systems such as IPTV are expanded to high quality surround at the same data rate as previously required by the transmission of stereo sound only; this is also true for digital radio, TV broadcasting stations and mobile TV services. All legacy devices will continue to play back the program in usual mono or stereo quality; new receivers will play back the same signal in highquality multichannel sound. Broadcasters can offer both services in one singlestream, meaning that there is no longer a need to simulcast stereo and multichannel programs. Furthermore, broadcasters can integrate MPEG Surround easily and cost-effectively into their existing broadcast systems. For mobile services, MPEG Surround supports a binaural mode to play back surround sound over conventional stereo headphones. MPEG Surround is part of several internationally recognized digital broadcasting standards, including DAB, DAB+, T-DMB (Korea) and ATIS (IPTV). It is also under consideration as a standard for mobile services, such as DVB-H, 3GPP, DMB radio (France) and DRM+.
Consumer electronic devices
With MPEG Surround, portable media players are enriched with a new dimension of surround sound, enabling users to enjoy a compelling surround experience. In the binaural mode that enables multichannel playback over conventional stereo earphones, they can listen to their favorite music in multichannel sound at any time and in any location. MPEG Surround in combination with AAC enables playback of the same file on an existing portable media player in stereo quality; simultaneously, MPEG Surround-enabled devices can play back the binaural version on portable devices or the multichannel version on surround set-ups at home or in the car.
Music and video download
Surround content is now easily accessible for download or streaming via online music stores and content websites. The same music file plays back on conventional stereo devices in usual stereo sound and at the same time represents high quality surround sound on MPEG Surround-enabled devices at home, in the car or on the move. The overall result is a smooth transition from stereo to multichannel music. The surround files are about the same size as those containing stereo content.