Complex exponential modulated filter bank for high frequency reconstruction or parametric stereo
First Claim
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1. A signal processing device for filtering an audio signal, the signal processing device comprising:
- a high frequency reconstructor or a 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 an amount; and
a synthesis filter bank that receives the modified complex-valued subband samples and generates time domain output audio samples,wherein the synthesis filter bank comprises synthesis filters (fk(n)) that are complex exponential modulated versions of a prototype filter (p0(n)) according to;
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Abstract
An apparatus and method are disclosed for filtering an audio signal. The apparatus includes a high frequency reconstructor or parametric stereo processor, a phase shifter, and a synthesis filter bank. The high frequency reconstructor or parametric stereo processor generates modified complex-valued subband samples. A phase shifter unshifts a phase of the modified complex-valued subband samples by an amount. The synthesis filter bank receives the modified complex valued subband samples and generates time domain output audio samples.
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11 Claims
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1. A signal processing device for filtering an audio signal, the signal processing device comprising:
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a high frequency reconstructor or a 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 an amount; and a synthesis filter bank that receives the modified complex-valued subband samples and generates time domain output audio samples, wherein the synthesis filter bank comprises synthesis filters (fk(n)) that are complex exponential modulated versions of a prototype filter (p0(n)) according to; - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method performed by an signal processing device for filtering an audio signal, the method comprising:
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generating modified complex valued subband samples through a high frequency reconstruction process or a parametric stereo process; unshifting a phase of the modified complex-valued subband samples by an amount; filtering the modified complex valued subband samples with a synthesis filter bank to generate time domain output audio samples, wherein the synthesis filter bank comprises synthesis filters (fk(n)) that are complex exponential modulated versions of a prototype filter (p0(n)) according to; - View Dependent Claims (11)
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Specification