Enhancement method for high-frequency reconstruction techniques combining frequency translation or folding with spectral envelope adjustment adjusting patched subband signal according to desired spectral envelope

摘要

The method involves filtering a low band signal through the analysis part of a digital filter bank and obtaining a set of subband signals. A number of the subband signals are patched from consecutive channels of the filter bank to consecutive channels in the synthesis part of a digital filter bank. Each of the subband signals is patched from a channel with frequency index k to a channel with frequency index j not equal to k. The patched subband signals are adjusted in accordance to a desired spectral envelope. The adjusted subband signals are filtered through the synthesis part of a digital filter bank. An envelope adjusted and frequency translated or folded signal is obtained. An Independent claim is included for an apparatus for enhancement of source coding systems using high-frequency reconstruction techniques.