view trunk/src/Modules/SAI/ModuleSAI.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 2006-2010, 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 SAI module
 */

/*
 * \author Thomas Walters <[e-mail]>
 * \date created 2007/08/29
 * \version \$Id$
 */
#include <cmath>

#include "Modules/SAI/ModuleSAI.h"

namespace aimc {
ModuleSAI::ModuleSAI(Parameters *parameters) : Module(parameters) {
  module_identifier_ = "weighted_sai";
  module_type_ = "sai";
  module_description_ = "Stabilised auditory image";
  module_version_ = "$Id$";

  min_delay_ms_ = parameters_->DefaultFloat("sai.min_delay_ms", 0.0f);
  max_delay_ms_ = parameters_->DefaultFloat("sai.max_delay_ms", 35.0f);
  strobe_weight_alpha_ = parameters_->DefaultFloat("sai.strobe_weight_alpha",
                                                   0.5f);
  buffer_memory_decay_ = parameters_->DefaultFloat("sai.buffer_memory_decay",
                                                   0.03f);
  frame_period_ms_ = parameters_->DefaultFloat("sai.frame_period_ms", 20.0f);

  max_concurrent_strobes_
    = parameters_->DefaultInt("sai.max_concurrent_strobes", 50);

  min_strobe_delay_idx_ = 0;
  max_strobe_delay_idx_ = 0;
  sai_decay_factor_ = 0.0f;
  fire_counter_ = 0;
}

bool ModuleSAI::InitializeInternal(const SignalBank &input) {
  // The SAI output bank must be as long as the SAI's Maximum delay.
  // One sample is added to the SAI buffer length to account for the
  // zero-lag point
  int sai_buffer_length = 1 + floor(input.sample_rate() * max_delay_ms_
                                    / 1000.0f);
  channel_count_ = input.channel_count();

  // Make an output SignalBank with the same number of channels and centre
  // frequencies as the input, but with a different buffer length
  if (!output_.Initialize(input.channel_count(),
                          sai_buffer_length,
                          input.sample_rate())) {
    LOG_ERROR("Failed to create output buffer in SAI module");
    return false;
  }
  for (int i = 0; i < input.channel_count(); ++i) {
    output_.set_centre_frequency(i, input.centre_frequency(i));
  }

  // sai_temp_ will be initialized to zero
  if (!sai_temp_.Initialize(output_)) {
    LOG_ERROR("Failed to create temporary buffer in SAI module");
    return false;
  }

  frame_period_samples_ = floor(input.sample_rate() * frame_period_ms_
                                / 1000.0f);
  min_strobe_delay_idx_ = floor(input.sample_rate() * min_delay_ms_
                                / 1000.0f);
  max_strobe_delay_idx_ = floor(input.sample_rate() * max_delay_ms_
                                / 1000.0f);

  // Make sure we don't go past the output buffer's upper bound
  if (max_strobe_delay_idx_ > output_.buffer_length()) {
    max_strobe_delay_idx_ = output_.buffer_length();
  }

  // Define decay factor from time since last sample (see ti2003)
  sai_decay_factor_ = pow(0.5f, 1.0f / (buffer_memory_decay_
                                        * input.sample_rate()));

  // Precompute strobe weights
  strobe_weights_.resize(max_concurrent_strobes_);
  for (int n = 0; n < max_concurrent_strobes_; ++n) {
    strobe_weights_[n] = pow(1.0f / (n + 1), strobe_weight_alpha_);
  }

  ResetInternal();

  return true;
}

void ModuleSAI::ResetInternal() {
  // Active Strobes
  output_.Clear();
  sai_temp_.Clear();
  active_strobes_.clear();
  active_strobes_.resize(channel_count_);
  fire_counter_ = frame_period_samples_ - 1;
}

void ModuleSAI::Process(const SignalBank &input) {
  // Reset the next strobe times
  next_strobes_.clear();
  next_strobes_.resize(output_.channel_count(), 0);

  // Offset the times on the strobes from the previous buffer
  for (int ch = 0; ch < input.channel_count(); ++ch) {
    active_strobes_[ch].ShiftStrobes(input.buffer_length());
  }

  // Loop over samples to make the SAI
  for (int i = 0; i < input.buffer_length(); ++i) {
    float decay_factor = pow(sai_decay_factor_, fire_counter_);
    // Loop over channels
    for (int ch = 0; ch < input.channel_count(); ++ch) {
      // Local convenience variables
      StrobeList &active_strobes = active_strobes_[ch];
      int next_strobe_index = next_strobes_[ch];

      // Update strobes
      // If we are up to or beyond the next strobe...
      if (next_strobe_index < input.strobe_count(ch)) {
        if (i == input.strobe(ch, next_strobe_index)) {
          // A new strobe has arrived.
          // If there are too many strobes active, then get rid of the
          // earliest one
          if (active_strobes.strobe_count() >= max_concurrent_strobes_) {
            active_strobes.DeleteFirstStrobe();
          }

          // Add the active strobe to the list of current strobes and
          // calculate the strobe weight
          float weight = 1.0f;
          if (active_strobes.strobe_count() > 0) {
            int last_strobe_time = active_strobes.Strobe(
              active_strobes.strobe_count() - 1).time;

            // If the strobe occured within 10 impulse-response
            // cycles of the previous strobe, then lower its weight
            weight = (i - last_strobe_time) / input.sample_rate()
                     * input.centre_frequency(ch) / 10.0f;
            if (weight > 1.0f)
              weight = 1.0f;
          }
          active_strobes.AddStrobe(i, weight);
          next_strobe_index++;


          // Update the strobe weights
          float total_strobe_weight = 0.0f;
          for (int si = 0; si < active_strobes.strobe_count(); ++si) {
            total_strobe_weight += (active_strobes.Strobe(si).weight
              * strobe_weights_[active_strobes.strobe_count() - si - 1]);
          }
          for (int si = 0; si < active_strobes.strobe_count(); ++si) {
            active_strobes.SetWorkingWeight(si,
              (active_strobes.Strobe(si).weight
               * strobe_weights_[active_strobes.strobe_count() - si - 1])
              / total_strobe_weight);
          }
        }
      }

      // Remove inactive strobes
      while (active_strobes.strobe_count() > 0) {
        // Get the relative time of the first strobe, and see if it exceeds
        // the maximum allowed time.
        if ((i - active_strobes.Strobe(0).time) > max_strobe_delay_idx_)
          active_strobes.DeleteFirstStrobe();
        else
          break;
      }

      // Update the SAI buffer with the weighted effect of all the active
      // strobes at the current sample
      for (int si = 0; si < active_strobes.strobe_count(); ++si) {
        // Add the effect of active strobe at correct place in the SAI buffer
        // Calculate 'delay', the time from the strobe event to now
        int delay = i - active_strobes.Strobe(si).time;

        // If the delay is greater than the (user-set)
        // minimum strobe delay, the strobe can be used
        if (delay >= min_strobe_delay_idx_ && delay < max_strobe_delay_idx_) {
          // The value at be added to the SAI
          float sig = input.sample(ch, i);

          // Weight the sample correctly
          sig *= active_strobes.Strobe(si).working_weight;

          // Adjust the weight acording to the number of samples until the
          // next output frame
          sig *= decay_factor;

          // Update the temporary SAI buffer
          sai_temp_.set_sample(ch, delay, sai_temp_.sample(ch, delay) + sig);
        }
      }

      next_strobes_[ch] = next_strobe_index;
    }  // End loop over channels

    fire_counter_--;

    // Check to see if we need to output an SAI frame on this sample
    if (fire_counter_ <= 0) {
      // Decay the SAI by the correct amount and add the current output frame
      float decay = pow(sai_decay_factor_, frame_period_samples_);

      for (int ch = 0; ch < input.channel_count(); ++ch) {
        for (int i = 0; i < output_.buffer_length(); ++i) {
          output_.set_sample(ch, i,
                             sai_temp_[ch][i] + output_[ch][i] * decay);
        }
      }

      // Zero the temporary signal
      for (int ch = 0; ch < sai_temp_.channel_count(); ++ch) {
        for (int i = 0; i < sai_temp_.buffer_length(); ++i) {
          sai_temp_.set_sample(ch, i, 0.0f);
        }
      }

      fire_counter_ = frame_period_samples_ - 1;

      // Transfer the current time to the output buffer
      output_.set_start_time(input.start_time() + i);
      PushOutput();
    }
  }  // End loop over samples
}

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