Fast and Precise Dequantization Algorithm in MP3/AAC Decoding Based on Chebyshev Approximation Polynomial

This paper proposes a fast and precise dequantization algorithm based on Chebyshev approximationpolynomial for MP3/AAC decoding. Due to the propertiesof Chebyshev approximation polynomial, compared withany other polynomial of the same degree, the infinity normof proposed algorithm reaches minimum. In contrast to theconventional method, the average error is reduced from0.03161 to 0.00051066 at the cost of two additional multiplications. The SNR (signal to noise ratio) for MP3/AACfiles is enhanced about 8dB averagely.