A fast algorithm for modified discrete cosine transform

This paper presents a fast algorithm for modified discrete cosine transform (MDCT), which is widely used in the coding of wide-band audio signals. By simple time shift and reverse, the MDCT is computed using Lee's (1984) fast cosine transform (FCT). The number of real multiplications is reduced from 2N/sup 2/ to (N/2)log/sub 2/N+N, half of that of the FFT based algorithm. The algorithm renders a simple and symmetric structure.