SCALABLE COMPRESSED AUDIO BIT STREAM AND CODEC USING A HIERARCHICAL FILTERBANK AND MULTICHANNEL JOINT CODING

摘要

A method for encoding an audio input signal to form a scaled bit stream (116)having a datarate less than or approximately equal to a desired data rate. A hierarchicalfilterbank 2100decomposes the input signal into a multi-resolution time/frequencyrepresentation fromwhich the encoder can efficiently extract both tonal 2106 and residualcomponents 2117.The components are ranked and then quantized with reference to the samemasking functionor different psychoacoustic criteria. The selected tonal components aresuitably encodedusing differential coding extended to multichannel audio. The time-sample andscale factorcomponents that make up the residual components are encoded using jointchannel coding(JCC) extended to multichannel audio.