Patent ID: 9691400
Date: 2017-06-27
CPC Classifications: G10L

Claim:
1. A method for decoding an encoded audio bitstream, the method comprising: receiving the encoded audio bitstream, the encoded audio bitstream containing a lowband audio signal and envelope data; extracting and decoding the lowband audio signal from the encoded audio bitstream to generate a decoded lowband audio signal; extracting and decoding the envelope data from the encoded audio bitstream to generate decoded spectral envelope data; filtering the decoded lowband signal with an analysis filterbank to produce lowband subband signals, wherein the analysis filterbank is maximally decimated; generating a highband signal by copying a number of lowband subband signals from consecutive lowband channels to consecutive highband channels to form a patch, wherein the generating is performed more than once so as to produce more than one patch; adjusting a spectral envelope of the highband signal using the decoded spectral envelope data; filtering the lowband subband signals and the highband signal with a synthesis filterbank to produce a digital wideband output audio signal, wherein a number of channels of the synthesis filterbank is different than a number of channels of the analysis filterbank, wherein the generating further comprises frequency translating a complex subband signal in a source area channel having an index i to a complex subband signal in a reconstruction range channel having an index j and frequency translating a complex subband signal in a source area channel having an index i+1 to a complex subband signal in a reconstruction range channel having an index j+1.