Time versus Frequency Resolution in a Low-Rate, High Quality Audio Transform Coder

An adaptive block size transform coder for high quality music has been developed. The adaptability of the input size of the transform combined with the properties of the transform as developed in the Dolby AC-2 technology allows one to exploit both maximum time and frequency resolution while keeping the bit rate as low as 128 kb/s per channel. The low complexity of the system permits a real-time implementation of encoder or decoder using one general purpose, programmable DSP chip per channel pair.