Development and evaluation of an over-sampled wavelet packet audio coder
Teddy Surya Gunawan, F. Sinaga, Eliathamby Ambikairajah · 2006
Many existing audio coders use a critically sampled discrete wavelet transform (DWT) for the decomposition of audio signals. While the aliasing present in the wavelet packet coefficients is cancelled in the decoder, these coders normally perform the calculation of the simultaneous masking threshold directly on these aliased coefficients. This paper describes the development of an over-sampled wavelet packet encoder, which is used to provide alias-free coefficients for accurate masking threshold calculation. Evaluation of the new coder using subjective and objective tests reveals that the oversampled wavelet packet outperforms the critically sampled wavelet packet scheme as used in conventional audio coders such as MPEG.