LOW BIT RATE TRANSFORM CODER, DECODER AND ENCODER/DECODER FOR HIGH QUALITY AUDIO

摘要

A transform encoder/decoder system employs a discrete transform, adaptive transform coefficient quantization, and adaptive bit allocation to encode high-quality music including broadcast and compact disc applications at low bit rates (128 kBits per second). Techniques are employed to reduce the amount of computation required to implement discrete transforms which are analogous to a critically sampled single-sideband analysis-synthesis system. Two embodiments include the Evenly-Stacked Time-Domain Aliasing Cancellation (TDAC) transform and the Oddly-Stacked TDAC transform.