Compression of high-quality audio using a hybrid LPC discrete wavelet transform algorithm

This paper examines a new method for coding high-quality digital audio signals based on a combination of linear predictive coding (LPC) and the discrete wavelet transform (DWT). In this method, a linear predictor is first used to model each audio frame. Then, the prediction error is analysed using the DWT. The LPC coefficients and DWT coefficients are quantised using a novel bit allocation scheme which minimises the overall quantisation error with respect to the masking threshold. After Huffman coding, the proposed coder is capable of delivering near-transparent audio signal quality at encoding bitrates of around 90-96 kb/s. Objective and subjective results suggest that the proposed coder operating at 90-96 kb/s has a performance comparable to that of the MPEG layer II codec operating at 128 kb/s.