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32 #include "platform/PlatformExport.h"
33 #include "platform/audio/AudioArray.h"
34 #include "wtf/Complex.h"
35 #include <sys/types.h>
39 #endif // USE(WEBAUDIO_IPP)
43 // A basic biquad (two-zero / two-pole digital filter)
45 // It can be configured to a number of common and very useful filters:
46 // lowpass, highpass, shelving, parameteric, notch, allpass, ...
48 class PLATFORM_EXPORT Biquad FINAL {
53 void process(const float* sourceP, float* destP, size_t framesToProcess);
55 // frequency is 0 - 1 normalized, resonance and dbGain are in decibels.
56 // Q is a unitless quality factor.
57 void setLowpassParams(double frequency, double resonance);
58 void setHighpassParams(double frequency, double resonance);
59 void setBandpassParams(double frequency, double Q);
60 void setLowShelfParams(double frequency, double dbGain);
61 void setHighShelfParams(double frequency, double dbGain);
62 void setPeakingParams(double frequency, double Q, double dbGain);
63 void setAllpassParams(double frequency, double Q);
64 void setNotchParams(double frequency, double Q);
66 // Set the biquad coefficients given a single zero (other zero will be conjugate)
67 // and a single pole (other pole will be conjugate)
68 void setZeroPolePairs(const Complex& zero, const Complex& pole);
70 // Set the biquad coefficients given a single pole (other pole will be conjugate)
71 // (The zeroes will be the inverse of the poles)
72 void setAllpassPole(const Complex& pole);
74 // Resets filter state
77 // Filter response at a set of n frequencies. The magnitude and
78 // phase response are returned in magResponse and phaseResponse.
79 // The phase response is in radians.
80 void getFrequencyResponse(int nFrequencies,
81 const float* frequency,
83 float* phaseResponse);
85 void setNormalizedCoefficients(double b0, double b1, double b2, double a0, double a1, double a2);
87 // Filter coefficients. The filter is defined as
89 // y[n] + m_a1*y[n-1] + m_a2*y[n-2] = m_b0*x[n] + m_b1*x[n-1] + m_b2*x[n-2].
97 void processFast(const float* sourceP, float* destP, size_t framesToProcess);
98 void processSliceFast(double* sourceP, double* destP, double* coefficientsP, size_t framesToProcess);
100 AudioDoubleArray m_inputBuffer;
101 AudioDoubleArray m_outputBuffer;
103 #elif USE(WEBAUDIO_IPP)
104 IppsIIRState64f_32f* m_biquadState;
105 Ipp8u* m_ippInternalBuffer;
109 double m_x1; // input delayed by 1 sample
110 double m_x2; // input delayed by 2 samples
111 double m_y1; // output delayed by 1 sample
112 double m_y2; // output delayed by 2 samples