CONF Motlicek_TSD2008_2008/IDIAP Perceptually motivated Sub-band Decomposition for FDLP Audio Coding Motlicek, Petr Ganapathy, Sriram Hermansky, Hynek Garudadri, Harinath Athineos, Marios Audio Coding Frequency Domain Linear Prediction (FDLP) speech coding EXTERNAL http://publications.idiap.ch/attachments/papers/2008/Motlicek_TSD2008_2008.pdf PUBLIC Text, Speech and Dialogue Brno, Czech Republic Series of Lecture Notes in Artificial Intelligence (LNAI) 5246 435-442 978-3-540-87390-7 2008 Springer-Verlag Berlin, Heidelberg September 2008 This paper describes employment of non-uniform QMF decomposition to increase the efficiency of a generic wide-band audio coding system based on Frequency Domain Linear Prediction (FDLP). The base line FDLP codec, operating at high bit-rates (~136 kbps,',','), exploits a uniform QMF decomposition into 64 sub-bands followed by sub-band processing based on FDLP. Here, we propose a non-uniform QMF decomposition into 32 frequency sub-bands obtained by merging 64 uni- form QMF bands. The merging operation is performed in such a way that bandwidths of the resulting critically sampled sub-bands emulate the characteristics of the critical band filters in the human auditory system. Such frequency decomposition, when employed in the FDLP audio codec, results in a bit-rate reduction of 40% over the base line. We also describe the complete audio codec, which provides high-fidelity audio compression at ~66 kbps. In subjective listening tests, the FDLP codec outperforms MPEG-1 Layer 3 (MP3) and achieves similar qualities as MPEG-4 HE-AAC codec.