A New Efficient Method of Computing MDCT in MP3 Audio Coding

In this paper, a new efficient method of computing modified discrete cosine transform (MDCT) in MP3 audio coding is proposed. We first define a scaled discrete cosine transform (SDCT), then convert N-point MDCT to N/2-point SDCT. Next we factor N/2-point SDCT matrix mathematically. The factored SDCT matrices are used to develop a fast MDCT algorithm for realizing N-point MDCT. We show that the proposed MDCT algorithm outperforms all fast MDCTalgorithms developed in the literature in terms of computational complexity.