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// Copyright 2008-2010, Thomas Walters
//
// AIM-C: A C++ implementation of the Auditory Image Model
// http://www.acousticscale.org/AIMC
//
// 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.

/*! \file
 *  \brief Dick Lyon's Pole-Zero Filter Cascade - implemented in C++ by Tom
 *  Walters from the AIM-MAT module based on Dick Lyon's code.
 *
 *  \author Thomas Walters <tom@acousticscale.org>
 *  \date created 2008/02/05
 * \version \$Id$
 */

#ifndef _AIMC_MODULES_BMM_PZFC_H_
#define _AIMC_MODULES_BMM_PZFC_H_

#include <vector>

#include "Support/Module.h"
#include "Support/Parameters.h"
#include "Support/SignalBank.h"

namespace aimc {
using std::vector;
class ModulePZFC : public Module {
 public:
  explicit ModulePZFC(Parameters *pParam);
  virtual ~ModulePZFC();

  /*! \brief Process a buffer
   */
  virtual void Process(const SignalBank &input);

 private:
  /*! \brief Reset all internal state variables to their initial values
   */
  virtual void ResetInternal();

  /*! \brief Prepare the module
   *  \param input Input SignalBank
   *  \param output true on success false on failure
   */
  virtual bool InitializeInternal(const SignalBank &input);

  /*! \brief Set the filterbank parameters according to a fit matrix from Unoki
   *  and Lyon's fitting routine
   */
  bool SetPZBankCoeffsERBFitted();

  /*! \brief Set the filterbank parameters using the non-fitted parameter
   * values, spaced along an ERB scale
   */
  bool SetPZBankCoeffsERB();

  /*! \brief Set the filterbank parameters using the non-fitted parameter
   * values, using the Greenwood formula (?) for channel spacing.
   */
  bool SetPZBankCoeffsOrig();

  /*! \brief Sets the general filterbank coefficients
   */
  bool SetPZBankCoeffs();

  /*! \brief Automatic Gain Control
   */
  void AGCDampStep();

  /*! \brief Detector function - halfwave rectification etc. Used internally,
   *  but not applied to the output.
   */
  float DetectFun(float fIN);

  /*! \brief Minimum
   */
  inline float Minimum(float a, float b);

  int channel_count_;
  int buffer_length_;
  int agc_stage_count_;
  float sample_rate_;
  float last_input_;

  // Parameters
  // User-settable values
  float pole_damping_;
  float zero_damping_;
  float zero_factor_;
  float step_factor_;
  float bandwidth_over_cf_;
  float min_bandwidth_hz_;
  float agc_factor_;
  float cf_max_;
  float cf_min_;
  float mindamp_;
  float maxdamp_;
  bool do_agc_step_;
  bool use_fitted_parameters_;

  // Internal Buffers
  // Initialised once
  vector<float> pole_dampings_;
  vector<float> agc_epsilons_;
  vector<float> agc_gains_;
  vector<float> pole_frequencies_;
  vector<float> za0_;
  vector<float> za1_;
  vector<float> za2_;
  vector<float> rmin_;
  vector<float> rmax_;
  vector<float> xmin_;
  vector<float> xmax_;

  // Modified by algorithm at each time step
  vector<float> detect_;
  vector<vector<float> > agc_state_;
  vector<float> state_1_;
  vector<float> state_2_;
  vector<float> previous_out_;
  vector<float> pole_damps_mod_;
  vector<float> inputs_;
};
}

#endif  // _AIMC_MODULES_BMM_PZFC_H_
author	tomwalters
date	Mon, 07 Jun 2010 08:34:49 +0000
parents	c5f5e9569863
children