| 摘要 |
A method and apparatus for improving the computational efficiency of perfect reconstruction audio filter banks is disclosed. The i nvention implements an analysis filter bank (350) for generating (324) a plurality of sub-band signals from an input (320) audio signal utilizing a modified windowing transformation followed by a discrete cosine transform. Since the discrete cosine transform can be performed in a computationally efficient manner, a net savings in the computational complexity of the system is obtained relative to prior art filter systems which use a cosine modulation of a set of polyphase components obtained from a windowing transformation. The synthesis filter bank which recombines the sub-band signal to regenerate the original audio signal is implemented with the aid of the inverse discrete cosine transformation thereby providing a significant computational savings. |
