Efficient FFT Algorithm for Psychoacoustic Model of the MPEG-4 AAC

Jae-Seong LEE  Chang-Joon LEE  Young-Cheol PARK  Dae-Hee YOUN  

Publication
IEICE TRANSACTIONS on Information and Systems   Vol.E92-D   No.12   pp.2535-2539
Publication Date: 2009/12/01
Online ISSN: 1745-1361
DOI: 10.1587/transinf.E92.D.2535
Print ISSN: 0916-8532
Type of Manuscript: LETTER
Category: Speech and Hearing
Keyword: 
FFT,  MDCT,  MDST,  psychoacoustic model,  MPEG-4 AAC,  

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Summary: 
This paper proposes an efficient FFT algorithm for the Psycho-Acoustic Model (PAM) of MPEG-4 AAC. The proposed algorithm synthesizes FFT coefficients using MDCT and MDST coefficients through circular convolution. The complexity of the MDCT and MDST coefficients is approximately half of the original FFT. We also design a new PAM based on the proposed FFT algorithm, which has 15% lower computational complexity than the original PAM without degradation of sound quality. Subjective as well as objective test results are presented to confirm the efficiency of the proposed FFT computation algorithm and the PAM.