Patent ID: 7203717

Claim:
A method of evaluating a modified discrete cosine transform (MDCT) of an input sequence of complex signal data in an audio signal processor, comprising: using a Fast Fourier Transform (FFT), wherein the FFT is a N/2-Point FFT, to evaluate, the complex data, from audio signals and wherein the MDCT is X k = ∑ n = 0 n = N - 1 ⁢ ⁢ x ⁡ [ n ] * cos ⁡ ( 2 ⁢ π * ( 2 ⁢ n + 1 ) * ( 2 ⁢ k + 1 ) / 4 ⁢ N + π * ( 2 ⁢ k + 1 ) / 4 ) k = 0 ⁢ ⁢ … ⁢ ⁢ ( N / 2 - 1 ) where x[n] represents the input sequence and N is the number of data samples in the sequence.