Patent ID: 9716486
Date: 2017-07-25
CPC Classifications: G06F,G10L,H03H,H04R,H04S

Claim:
1. A signal processing device for filtering an audio signal, the signal processing device comprising: an analysis filter bank that receives real valued time domain input audio samples and generates complex-valued subband samples; a phase shifter that shifts a phase of the complex-valued subband samples by an amount; a high frequency reconstructor or parametric stereo processor that generates modified complex-valued subband samples; a phase shifter that unshifts a phase of the modified complex-valued subband samples by the amount; and a synthesis filter bank that receives the modified complex-valued subband samples and generates time domain output audio samples, wherein the analysis filter bank comprises analysis filters (h where M is a number of channels, the prototype filter (p wherein one or more of the analysis filter bank, the high frequency reconstructor, and the synthesis filter bank is implemented, at least in part, by one or more hardware elements of the signal processing device, and wherein the high frequency reconstructor comprises a spectral envelope adjuster that adjusts a spectral envelope of at least some of the complex valued subband samples.