Quality Enhancement of Low Bit Rate Mpeg1-Layer 3 Audio Based on Audio Resynthesis
Demetrios Cantzos, Chris Kyriakakis · Journal of the Audio Engineering Society · 2005
One of the most popular audio compression formats is indisputably the MPEG1-Layer 3 format which is based on the idea of low-bit transparent encoding. As these types of audio signals are starting to migrate from portable players with inexpensive headphones to higher quality home audio systems, it is becoming evident that higher bit rates may be required to maintain transparency. We propose a novel method that enhances low bit rate MP3 encoded audio segments by applying multichannel audio resynthesis methods in a post-processing stage or during decoding. Our algorithm employs the highly efficient Generalized Gaussian mixture model which, combined with cepstral smoothing, leads to very low cepstral reconstruction errors. In addition, residual conversion is applied which proves to significantly improve the enhancement performance. The method presented can be easily generalized to include other audio formats for which sound quality is an issue.