MP3 Surround is an extension of MP3 for multi-channel audio support including 5.1 surround sound. It was developed by Fraunhofer IIS in collaboration with Thomson and Agere Systems, and released in December 2004.
MP3 Surround is backward compatible with standard MP3. The data overhead is 16 kbit/s, which allows for file sizes similar to standard stereo MP3 files. The file size is approximately 10% larger than that of a typical MP3 file. The current evaluation encoder is licensed for personal and non-commercial uses. An MP3 Surround file can be created from 5 or 6 channels of WAV audio.
Several companies, such as DivX, Inc. and Magix, have announced support for the new codec.DivX, Inc. released their first player with MP3 Surround support on September 6, 2006.
Uzelac studied at the University of Zagreb's Faculty of Electrical Engineering and Computing (FER) under professor Mario Kovač, working on MP3 software decoding. In 1997 he created AMP, and also graduated with an engineer's degree from FER. Two students from the University of Utah, Justin Frankel and Dmitry Boldyrev adapted it to work on Windows and called it Winamp.
In January 2006, Thomson and Fraunhofer IIS also released two new companion technologies: Ensonido, which allows playback of MP3 Surround 5.1 channel sound through stereo headphones, and MP3 SX, which upgrades standard stereo mp3 file to mp3 surround files.