filter.cpp

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#include "filter.h"
#include "Bela.h"
#include <libraries/math_neon/math_neon.h>
#include <libraries/Biquad/QuadBiquad.h>
 
const float sq2 = sqrtf_neon(2.0f);
 
Filter::Filter(const float fs) {
 
  /* Initialize Biquad filters for each signal. */
  /* ******** High-pass filter for microphones */
  Biquad::Settings hp8k_mic_settings{
    .fs = fs,
      .type = Biquad::highpass,
      .cutoff = MIC_HP_CUTON8k,
      .q = sq2,
      .peakGainDb = 0.0f,
  };
  Biquad::Settings lp_mic_settings{
    .fs = fs,
      .type = Biquad::lowpass,
      .cutoff = MIC_LP_CUTOFF,
      .q = sq2,
      .peakGainDb = 0.0f,
  };
 
  Biquad::Settings hp_acc_settings {
    .fs = fs,
      .type = Biquad::highpass,
      .cutoff = ACC_HP_CUTON,
      .q = sq2,
      .peakGainDb = 0.0f,
  };
  Biquad::Settings lp_acc_settings{
    .fs = fs,
      .type = Biquad::lowpass,
      .cutoff = ACC_LP_CUTOFF,
      .q = sq2,
      .peakGainDb = 0.0f,
  };
  Biquad::Settings hp2k_mic_settings{
    .fs = fs,
      .type = Biquad::highpass,
      .cutoff = MIC_HP_CUTON2k,
      .q = sq2,
      .peakGainDb = 0.0f,
  };
 
  Biquad::Settings imu_accelerometer_hp_settings{
    .fs = fs,
      .type = Biquad::highpass,
      .cutoff = IMU_ACC_CUTON,
      .q = sq2,
      .peakGainDb = 0.0f,
  };
 
  BiquadCoeffT<float> hp8k_mic_coefs(hp8k_mic_settings);
  BiquadCoeffT<float> hp2k_mic_coefs(hp2k_mic_settings);
  BiquadCoeffT<float> lp_mic_coefs(lp_mic_settings);
  BiquadCoeffT<float> hp_acc_coefs(hp_acc_settings);
  BiquadCoeffT<float> lp_acc_coefs(lp_acc_settings);
  BiquadCoeffT<float> imu_accelerometer_hp_coefs(
      imu_accelerometer_hp_settings);
 
  _filters1= new QuadBiquad();
  _filters2= new QuadBiquad();
  _filters3= new QuadBiquad();
 
  _filters1->filters.at(0) = hp8k_mic_coefs;
  _filters1->filters.at(1) = hp8k_mic_coefs;
 
  /* ******** Low-pass filter for microphones */
  _filters1->filters.at(2) = lp_mic_coefs;
  _filters1->filters.at(3) = lp_mic_coefs;
 
  /* ******** High-pass and lowpass filters for VPU */
  _filters2->filters.at(0) = hp_acc_coefs;
  _filters2->filters.at(1) = lp_acc_coefs;
 
  /* ******** High-pass 2k filters for mics */
  _filters2->filters.at(2) = hp2k_mic_coefs;
  _filters2->filters.at(3) = hp2k_mic_coefs;
 
  /* IMU accelerometer high-pass */
  _filters3->filters.at(0) = imu_accelerometer_hp_coefs;
 
  _filters1->update();
  _filters2->update();
  _filters3->update();
}
void Filter::filter(const RawFrame& rawframe,FilteredFrame& filteredframe) {
 
  float filters1_inout[] = {
    // Mic samples for the 8k high-pass filter
    rawframe[RAW_MICT],
    rawframe[RAW_MICW],
    // Mic samples for the 500 Hz low-pass filter
    rawframe[RAW_MICT],
    rawframe[RAW_MICW],
  };
  float filters2_inout[] = {  
    // High-pass filter 2 kHz for VPU
    rawframe[RAW_VPU],
    // Low-pass filter 500 Hz for VPU
    rawframe[RAW_VPU],
 
    // High-pass filter 2 kHz for mic
    rawframe[RAW_MICT],
    rawframe[RAW_MICW]
  };
  float filters3_inout[] = {  
    // High-pass the IMU acceleration value.
    rawframe[RAW_IMU_ACC],
    0,
    0,
    0,
  };
 
  _filters1->process(filters1_inout);
  _filters2->process(filters2_inout);
  _filters3->process(filters3_inout);
 
  filteredframe[FILT_RAW_MICT] = rawframe[RAW_MICT];
  filteredframe[FILT_RAW_MICW] = rawframe[RAW_MICW];
  filteredframe[FILT_RAW_VPU] = rawframe[RAW_VPU];
 
  filteredframe[FILT_HP8k_MICT] = filters1_inout[0];
  filteredframe[FILT_HP8k_MICW] = filters1_inout[1];
 
  filteredframe[FILT_LP500_MICT] = filters1_inout[2];
  filteredframe[FILT_LP500_MICW] = filters1_inout[3];
 
  filteredframe[FILT_HP2k_VPU] = filters2_inout[0];
  filteredframe[FILT_LP500_VPU] = filters2_inout[1];
 
  filteredframe[FILT_HP2k_MICT] = filters2_inout[2];
  /* filteredframe[FILT_HP2k_MICW] = filters2_inout[3]; */
 
  filteredframe[FILT_PEDAL] = rawframe[RAW_PEDAL];
  filteredframe[FILT_IMU_ROT] = rawframe[RAW_IMU_ROT];
  filteredframe[FILT_HP_IMU_ACC] = filters3_inout[0];
 
}
Filter::~Filter() {
  delete _filters1;
  delete _filters2;
  delete _filters3;
}