BILINEAR ALGORITHMS AND VLSI IMPLEMENTATIONS OF FORWARD AND INVERSE MDCT WITH APPLICATIONS TO MP3 AUDIO

摘要

Methods and applications are provided for hardware efficient bilinear algorithms to compute MDCT/IMDCT of 4x3?n points. The algorithms for composite lengths have practical application in MPEG-1/2 layer III (MP3) audio encoding and decoding. The MDCT/IMDCT can be converted to type-IV discrete cosine transform. Using group theory, the present approach decomposes DCT-IV transform kernel matrix into groups of cyclic, Hankel and/or Toeplix matrices. Bilinear algorithms are then applied to efficiently evaluate these groups. When implemented in very large-scale integration, the bilinear algorithms have improved the critical path delays over other known solutions.