A Low Complexity Transform - Evolved DCT

This paper presents a new transform pair named Evolved DCT/IDCT (EDCT/IEDCT), which was used in the ITU-T G.718 Annex-B and G.729.1 Annex-E standardization. The EDCT/IEDCT is derived from N/4-point FFT implementation approach for MDCT or DCT. The symmetry of the new rotation factor results in clear storage complexity, compared to classical MDCT/DCT transform. The computational complexity is as efficient as the approach based on N/4-point FFT, and is clear faster than the traditional iterative implementation of Malvar algorithm. The transform pair can also reconstruct signal perfectly and be as substitution of classical MDCT/IMDCT and DCT/IDCT.