view trunk/carfac/car.h @ 690:76f749d29b48

Fix memory leak in CARFAC.

Also get rid of most uses of auto, which tend to hurt readability
unless the type name is particularly long, especially when it masks
pointers.

//
//  car.h
//  CARFAC Open Source C++ Library
//
//  Created by Alex Brandmeyer on 5/10/13.
//
// This C++ file is part of an implementation of Lyon's cochlear model:
// "Cascade of Asymmetric Resonators with Fast-Acting Compression"
// to supplement Lyon's upcoming book "Human and Machine Hearing"
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#ifndef CARFAC_CAR_H
#define CARFAC_CAR_H

#include "common.h"

// A CARParams structure stores the necessary information needed by a CARFAC
// object to design the set of CARCoeffs implementing 'The Cascade of
// Asymmetric Resonators' described in the chapter of the same name in Lyon's
// book "Human and Machine Hearing".
struct CARParams {
  CARParams() {
    velocity_scale = 0.1;
    v_offset = 0.04;
    min_zeta = 0.1;
    max_zeta = 0.35;
    first_pole_theta = 0.85 * kPi;
    zero_ratio = sqrt(2.0);
    high_f_damping_compression = 0.5;
    erb_per_step = 0.5;
    min_pole_hz = 30;
    erb_break_freq = 165.3;  // The Greenwood map's break frequency in Hertz.
    // Glassberg and Moore's high-cf ratio.
    erb_q = 1000 / (24.7 * 4.37);
  }

  FPType velocity_scale;  // Used for the velocity nonlinearity.
  FPType v_offset;  // The offset gives us quadratic part.
  FPType min_zeta;  // The minimum damping factor in mid-freq channels.
  FPType max_zeta;  // The maximum damping factor in mid-freq channels.
  FPType first_pole_theta;
  FPType zero_ratio;  // This is how far zero is above the pole.
  FPType high_f_damping_compression;  // A range from 0 to 1 to compress theta.
  FPType erb_per_step;
  FPType min_pole_hz;
  FPType erb_break_freq;
  FPType erb_q;
};

// CAR filter coefficients, which are derived from a set of CARParams.
struct CARCoeffs {
  FPType velocity_scale;
  FPType v_offset;
  ArrayX r1_coeffs;
  ArrayX a0_coeffs;
  ArrayX c0_coeffs;
  ArrayX h_coeffs;
  ArrayX g0_coeffs;
  ArrayX zr_coeffs;
};


// CAR filter state.
struct CARState {
  ArrayX z1_memory;
  ArrayX z2_memory;
  ArrayX za_memory;
  ArrayX zb_memory;
  ArrayX dzb_memory;
  ArrayX zy_memory;
  ArrayX g_memory;
  ArrayX dg_memory;
};

#endif  // CARFAC_CAR_H