MULTI-CHANNEL PREDICTIVE SUBBAND CODER USING PSYCHOACOUSTIC ADAPTIVE BIT ALLOCATION

摘要

A subband audio coder (12) employs perfect/non-perfect reconstruction filter s (34), predictive/non-predictive subband encoding (72), transient analysis (106), and psycho-acoustic/minimum mean-square-error (mms e) bit allocation (30) over time, frequency and the multiple audio channels to encode/decode a data stream to generate high fidelity reconstructed audio. The audio coder windows (64) the multi- channel audio signal such that the frame size, i.e., number of bytes, is constrained to lie in a desired range, and formats the encoded data so that the individual subframes can be played back as they are received thereby reducing latency. Furthermore, the audio coder processes the baseband portion (0-24kHz) of the audio bandwidth for sampling frequenci es of 48kHz and higher with the same encoding/decoding algorithm so that audio coder architecture is future compatible.