view trunk/src/Modules/Strobes/ModuleParabola.cc @ 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.

// Copyright 2007-2010, 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 Parabola strobe detection module - Using the 'parabloa' strobe
 * criterion from the AIM-MAT sf2003 module
 *
 * \author Thomas Walters <[e-mail]>
 * \date created 2007/08/01
 * \version \$Id$
 */

#include <limits.h>
#include <cmath>

#include "Modules/Strobes/ModuleParabola.h"

namespace aimc {
ModuleParabola::ModuleParabola(Parameters *params) : Module(params) {
  module_description_ = "sf2003 parabola algorithm";
  module_identifier_ = "parabola";
  module_type_ = "strobes";
  module_version_ = "$Id$";

  // Get data from parameters
  height_ = parameters_->DefaultFloat("parabola.height", 1.2f);
  parabw_ = parameters_->DefaultFloat("parabola.width_cycles", 1.5f);
  strobe_decay_time_ = parameters_->DefaultFloat("parabla.strobe_decay_time",
                                                 0.02f);
  channel_count_ = 0;
}

bool ModuleParabola::InitializeInternal(const SignalBank &input) {
  output_.Initialize(input);
  channel_count_ = input.channel_count();
  sample_rate_ = input.sample_rate();

  // Parameters for the parabola
  parab_a_.resize(channel_count_);
  parab_b_.resize(channel_count_);
  parab_wnull_.resize(channel_count_);
  parab_var_samples_.resize(channel_count_);

  for (int ch = 0; ch < channel_count_; ++ch) {
    parab_wnull_[ch] = parabw_ / input.centre_frequency(ch);
    parab_var_samples_[ch] = floor(parab_wnull_[ch] * sample_rate_);
    parab_a_[ch] = 4.0f * (1.0f - height_)
                   / (parab_wnull_[ch] * parab_wnull_[ch]);
    parab_b_[ch] = -parab_wnull_[ch] / 2.0f;
  }

  // Number of samples over which the threshold should decay
  strobe_decay_samples_ = floor(sample_rate_ * strobe_decay_time_);

  // Prepare internal buffers
  ResetInternal();

  return true;
}

void ModuleParabola::ResetInternal() {
  threshold_.clear();
  threshold_.resize(channel_count_, 0.0f);
  last_threshold_.clear();
  last_threshold_.resize(channel_count_, 0.0f);
  samples_since_last_strobe_.clear();
  samples_since_last_strobe_.resize(channel_count_, 0);

  prev_sample_.clear();
  prev_sample_.resize(channel_count_, 10000.0f);
  curr_sample_.clear();
  curr_sample_.resize(channel_count_, 5000.0f);
  next_sample_.clear();
  next_sample_.resize(channel_count_, 0.0f);
}

void ModuleParabola::Process(const SignalBank &input) {
  float decay_constant;

  for (int ch = 0; ch < output_.channel_count(); ch++) {
    output_.ResetStrobes(ch);
  }
  output_.set_start_time(input.start_time());

  // Loop across samples first, then channels
  for (int i = 0; i < input.buffer_length(); i++) {
    // Find strobes in each channel first
    for (int ch = 0; ch < input.channel_count(); ++ch) {
      // Shift all the samples by one
      // curr_sample is the sample at time (i - 1)
      prev_sample_[ch] = curr_sample_[ch];
      curr_sample_[ch] = next_sample_[ch];
      next_sample_[ch] = input.sample(ch, i);

      // Copy input signal to output signal
      output_.set_sample(ch, i, input.sample(ch, i));

      if (curr_sample_[ch] >= threshold_[ch]) {
        threshold_[ch] = curr_sample_[ch];
        if (prev_sample_[ch] < curr_sample_[ch]
            && next_sample_[ch] < curr_sample_[ch]) {
          // We have a strobe: set threshold and add strobe to the list
          output_.AddStrobe(ch, i - 1);
          last_threshold_[ch] = threshold_[ch];
          parab_var_samples_[ch] =
            floor(input.sample_rate()
                  * (parab_wnull_[ch] - (threshold_[ch]
                                         - 2.0f * parab_a_[ch]  *parab_b_[ch])
                                        / (2.0f * parab_a_[ch])));
        }
      }
      if (output_.strobe_count(ch) > 0) {
        samples_since_last_strobe_[ch] = (i - 1)
             - output_.strobe(ch, output_.strobe_count(ch) - 1);
      } else {
        samples_since_last_strobe_[ch] = UINT_MAX;
      }

      if (samples_since_last_strobe_[ch] > parab_var_samples_[ch]) {
        decay_constant = last_threshold_[ch] / strobe_decay_samples_;
        if (threshold_[ch] > decay_constant)
          threshold_[ch] -= decay_constant;
        else
          threshold_[ch] = 0.0f;
      } else {
        threshold_[ch] = last_threshold_[ch]
            * (parab_a_[ch] * pow((samples_since_last_strobe_[ch]
                                   / input.sample_rate() + parab_b_[ch]),
                                  2.0f) + height_);
      }
    }
  }

  PushOutput();
}



ModuleParabola::~ModuleParabola() {
}
}  // namespace aimc