view branches/carfac_cpp/src/CAR.cpp @ 621:d763637a05c5

Second check-in of Alex Brandmeyer's C++ implementation of CARFAC. Addressed style issues and completed implementation of remaining functions. Still needs proper testing of the output stages against the MATLAB version, and runtime functions need improvements in efficiency.

#include "CAR.h"
#include "CARFAC_common.h"
#include "CARFAC.h"
#include <cmath>
#include "unit_conversion.h"

CAR_parameters::CAR_parameters():
	  velocity_scale_(0.2),
	  v_offset_(0.01),
	  v2_corner_(0.2),
	  v_damp_max_(0.01),
	  min_zeta_(0.10),
	  first_pole_theta_(0.085*kPi),
	  zero_ratio_(sqrt(2)),
	  high_f_damping_compression_(0.5),
	  erb_per_step_(0.5),
	  min_pole_hz_(30),
	  erb_break_freq_(kDefaultErbBreakFreq),
	  erb_q_(kDefaultErbQ)
{
    // do nothing more!
}

CAR_coefficients::CAR_coefficients(CAR_parameters* car_params_p, float fs,
                                   FloatArray pole_freqs)
{

  float f = pow(car_params_p->zero_ratio_, 2) + 1;

  // TODO: dirty FloatArray initialization.
  r1_coeffs_= pole_freqs;
  a0_coeffs_= pole_freqs;
  c0_coeffs_= pole_freqs;
  h_coeffs_= pole_freqs;
  g0_coeffs_= pole_freqs;
  zr_coeffs_= pole_freqs;

  FloatArray theta = pole_freqs;

  float min_zeta_mod;
  float x;
  float ff = car_params_p->high_f_damping_compression_;

  // TODO: temp loop until we get eigen in  (or we just leave it like this)
  for(float i=0; i<pole_freqs.size(); i++){
      theta[i] *= (2*kPi*fs); // scalar mult.
      c0_coeffs_[i] = sin(theta[i]);
      a0_coeffs_[i] = cos(theta[i]);

      x = theta[i]/kPi;
      zr_coeffs_[i] = kPi * (x - ff * x*x*x);

      min_zeta_mod = (car_params_p->min_zeta_ + 0.25 * (ERB_Hz(
                      pole_freqs[i], car_params_p->erb_break_freq_,
                      car_params_p->erb_q_) / pole_freqs[i]
                     - car_params_p->min_zeta_));

      r1_coeffs_[i] = 1-zr_coeffs_[i]*min_zeta_mod;

      h_coeffs_[i] = c0_coeffs_[i] * f;

      //TODO: g0_coeffs_ calculated here for now. Let's talk about this, need
      // to see the whole picture of what makes sense.
      // Related: I believe CAR, IHC and AGC classes would be beneficial!
      float tmp = 1 - 2*r1_coeffs_[i]*a0_coeffs_[i] + r1_coeffs_[i]*r1_coeffs_[i];
      g0_coeffs_[i] = tmp / ( tmp + h_coeffs_[i]*r1_coeffs_[i]*c0_coeffs_[i]);
  }

}