An audio compression system using modified transform coding and dynamic bit allocation

A complete audio coding system which combines modified transform coding and dynamic bit allocation to achieve a two-channel, 15 kHz bandwidth, 256 kb/s data rate audio compression and decompression is proposed. The modified transformation is used for time-frequency representations of signals and the dynamic bit allocation scheme is used to progressively quantize the transform coefficients according to the rate distortion theory. Computer simulation results show that this system, which achieves high audio quality at the rate of 4 b/sample, possesses low computational complexity suitable for multimedia applications. This coding system can further be operated in the case of variable bit rate to allow application-specific ancillary data without drastic loss of signal quality. >