Complex exponential modulated filter bank for high frequency reconstruction or parametric stereo
First 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 high frequency reconstructor or parametric stereo processor that generates modified complex valued subband samples; 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 (hk(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 an analysis filter bank, a high frequency reconstructor or parametric stereo processor, and a synthesis filter bank. The analysis filterbank receives real-valued time domain input audio samples and generates complex valued subband samples. The high frequency reconstructor or parametric stereo processor modifies at least some of the complex valued subband samples. The synthesis filter bank receives the modified complex valued subband samples and generates time domain output audio samples. The analysis filter bank comprises analysis filters that are complex exponential modulated versions of a prototype filter with an arbitrary phase shift to reduce a complexity of the filter bank.
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Citations
10 Claims
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1. A signal processing device for filtering an audio signal, the signal processing device comprising:
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an analysis filter bank that receives real valued time domain input audio samples and generates complex valued subband samples; a high frequency reconstructor or parametric stereo processor that generates modified complex valued subband samples; 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 (hk(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)
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9. A method performed by a signal processing device for filtering an audio signal, the method comprising:
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receiving real-valued time domain input audio samples; filtering the real-valued time domain input audio samples with an analysis filter bank to generate complex valued subband samples; generating modified complex valued subband samples through a high frequency reconstruction or parametric stereo process; filtering the modified complex valued subband samples with a synthesis filter bank to generate time domain output audio samples, wherein the analysis filter bank comprises analysis filters (hk(n)) that are complex exponential modulated versions of a prototype filter (p0(n)) according to; - View Dependent Claims (10)
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Specification