alexbrandmeyer@643: //
alexbrandmeyer@643: //  agc.h
alexbrandmeyer@643: //  CARFAC Open Source C++ Library
alexbrandmeyer@643: //
alexbrandmeyer@643: //  Created by Alex Brandmeyer on 5/30/13.
alexbrandmeyer@643: //
alexbrandmeyer@643: // This C++ file is part of an implementation of Lyon's cochlear model:
alexbrandmeyer@643: // "Cascade of Asymmetric Resonators with Fast-Acting Compression"
alexbrandmeyer@643: // to supplement Lyon's upcoming book "Human and Machine Hearing"
alexbrandmeyer@643: //
alexbrandmeyer@643: // Licensed under the Apache License, Version 2.0 (the "License");
alexbrandmeyer@643: // you may not use this file except in compliance with the License.
alexbrandmeyer@643: // You may obtain a copy of the License at
alexbrandmeyer@643: //
alexbrandmeyer@643: //     http://www.apache.org/licenses/LICENSE-2.0
alexbrandmeyer@643: //
alexbrandmeyer@643: // Unless required by applicable law or agreed to in writing, software
alexbrandmeyer@643: // distributed under the License is distributed on an "AS IS" BASIS,
alexbrandmeyer@643: // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
alexbrandmeyer@643: // See the License for the specific language governing permissions and
alexbrandmeyer@643: // limitations under the License.
alexbrandmeyer@643: 
alexbrandmeyer@643: #ifndef CARFAC_AGC_H
alexbrandmeyer@643: #define CARFAC_AGC_H
alexbrandmeyer@643: 
alexbrandmeyer@643: #include <vector>
alexbrandmeyer@643: #include "common.h"
alexbrandmeyer@643: 
alexbrandmeyer@643: struct AGCParams {
alexbrandmeyer@643:   AGCParams() {
alexbrandmeyer@643:     num_stages = 4;
alexbrandmeyer@643:     agc_stage_gain = 2.0;
alexbrandmeyer@643:     time_constants.resize(num_stages);
alexbrandmeyer@643:     agc1_scales.resize(num_stages);
alexbrandmeyer@643:     agc2_scales.resize(num_stages);
alexbrandmeyer@643:     agc1_scales[0] = 1.0;
alexbrandmeyer@643:     agc2_scales[0] = 1.65;
alexbrandmeyer@643:     time_constants[0] = 0.002;
alexbrandmeyer@643:     for (int i = 1; i < num_stages; ++i) {
alexbrandmeyer@643:       agc1_scales[i] = agc1_scales[i - 1] * sqrt(2.0);
alexbrandmeyer@643:       agc2_scales[i] = agc2_scales[i - 1] * sqrt(2.0);
alexbrandmeyer@643:       time_constants[i] = time_constants[i - 1] * 4.0;
alexbrandmeyer@643:     }
alexbrandmeyer@643:     decimation = {8, 2, 2, 2};
alexbrandmeyer@643:     agc_mix_coeff = 0.5;
alexbrandmeyer@643:   }
alexbrandmeyer@643:   int num_stages;
alexbrandmeyer@643:   FPType agc_stage_gain;
alexbrandmeyer@643:   FPType agc_mix_coeff;
alexbrandmeyer@643:   std::vector<FPType> time_constants;
alexbrandmeyer@643:   std::vector<int> decimation;
alexbrandmeyer@643:   std::vector<FPType> agc1_scales;
alexbrandmeyer@643:   std::vector<FPType> agc2_scales;
alexbrandmeyer@643: };
alexbrandmeyer@643: 
alexbrandmeyer@643: struct AGCCoeffs {
alexbrandmeyer@643:   int num_agc_stages;
alexbrandmeyer@643:   FPType agc_stage_gain;
alexbrandmeyer@643:   FPType agc_epsilon;
alexbrandmeyer@643:   int decimation;
alexbrandmeyer@643:   FPType agc_pole_z1;
alexbrandmeyer@643:   FPType agc_pole_z2;
alexbrandmeyer@643:   int agc_spatial_iterations;
alexbrandmeyer@643:   FPType agc_spatial_fir_left;
alexbrandmeyer@643:   FPType agc_spatial_fir_mid;
alexbrandmeyer@643:   FPType agc_spatial_fir_right;
alexbrandmeyer@643:   int agc_spatial_n_taps;
alexbrandmeyer@643:   FPType agc_mix_coeffs;
alexbrandmeyer@643:   FPType agc_gain;
alexbrandmeyer@643:   FPType detect_scale;
alexbrandmeyer@643:   FPType decim;
alexbrandmeyer@643: };
alexbrandmeyer@643: 
alexbrandmeyer@643: struct AGCState {
alexbrandmeyer@643:   ArrayX agc_memory;
alexbrandmeyer@643:   ArrayX input_accum;
alexbrandmeyer@643:   int decim_phase;
alexbrandmeyer@643: };
alexbrandmeyer@643: 
alexbrandmeyer@643: #endif  // CARFAC_AGC_H