MPEG-2 AAC 디코더를 위한 고속 IMDCT 알고리즘

This paper proposes a new IFFT(Inverse Fast Fourier Transform) algorithm, which is proper for IMDCT((Inverse Modified Discrete Cosine Transform) of MPEG-2 AAC(Advanced Audio Coding) decoder. The IFFT used in 2 N -point IMDCT employ the bit-reverse data arrangement of inputs and N/4-IFFT to reduce the calculation cycles. We devised a new data arrangement algorithm of IFFT input and N/4 n+1 -IFFT and can reduce multiplication cycles, addition cycles, and ROM size.