annotate src/Modules/Features/ModuleGaussians.cc @ 611:0fbaf443ec82

Carfac C++ revision 3, indluding more style improvements. The output structs are now classes again, and have separate storage methods for each output structure along with flags in the Run and RunSegment methods to allow for only storing NAPs if desired.

// 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 Gaussian features - based on MATLAB code by Christian Feldbauer
 */

/*!
 * \author Thomas Walters <[e-mail]>
 * \date created 2008/06/23
 * \version \$Id$
 */

#include <math.h>

#ifdef _WINDOWS
#include <float.h>
#endif

#include "Modules/Features/ModuleGaussians.h"
#include "Support/Common.h"

namespace aimc {
ModuleGaussians::ModuleGaussians(Parameters *params) : Module(params) {
  // Set module metadata
  module_description_ = "Gaussian Fitting to SSI profile";
  module_identifier_ = "gaussians";
  module_type_ = "features";
  module_version_ = "$Id$";

  m_iParamNComp = parameters_->DefaultInt("gaussians.ncomp", 4);
  m_fParamVar = parameters_->DefaultFloat("gaussians.var", 115.0);
  m_fParamPosteriorExp = parameters_->DefaultFloat("gaussians.posterior_exp",
                                                   6.0);
  m_iParamMaxIt = parameters_->DefaultInt("gaussians.maxit", 250);

  // The parameters system doesn't support tiny numbers well, to define this
  // variable as a string, then convert it to a float afterwards
  parameters_->DefaultString("gaussians.priors_converged", "1e-7");
  priors_converged_ = parameters_->GetFloat("gaussians.priors_converged");
  output_positions_ = parameters_->DefaultBool("gaussians.positions", false);
}

ModuleGaussians::~ModuleGaussians() {
}

bool ModuleGaussians::InitializeInternal(const SignalBank &input) {
  m_pA.resize(m_iParamNComp, 0.0f);
  m_pMu.resize(m_iParamNComp, 0.0f);

  // Assuming the number of channels is greater than twice the number of
  // Gaussian components, this is ok
  output_component_count_ = 1; // Energy component
  if (input.channel_count() >= 2 * m_iParamNComp) {
    output_component_count_ += (m_iParamNComp - 1);
  } else {
    LOG_ERROR(_T("Too few channels in filterbank to produce sensible "
                 "Gaussian features. Either increase the number of filterbank"
                 " channels, or decrease the number of Gaussian components"));
    return false;
  }

  if (output_positions_) {
    output_component_count_ += m_iParamNComp;
  }

  output_.Initialize(output_component_count_, 1, input.sample_rate());

  m_iNumChannels = input.channel_count();
  m_pSpectralProfile.resize(m_iNumChannels, 0.0f);

  return true;
}

void ModuleGaussians::ResetInternal() {
  m_pSpectralProfile.clear();
  m_pSpectralProfile.resize(m_iNumChannels, 0.0f);
  m_pA.clear();
  m_pA.resize(m_iParamNComp, 0.0f);
  m_pMu.clear();
  m_pMu.resize(m_iParamNComp, 0.0f);
}

void ModuleGaussians::Process(const SignalBank &input) {
  if (!initialized_) {
    LOG_ERROR(_T("Module ModuleGaussians not initialized."));
    return;
  }
  output_.set_start_time(input.start_time());
  // Calculate spectral profile
  for (int ch = 0; ch < input.channel_count(); ++ch) {
    m_pSpectralProfile[ch] = 0.0f;
    for (int i = 0; i < input.buffer_length(); ++i) {
      m_pSpectralProfile[ch] += input[ch][i];
    }
    m_pSpectralProfile[ch] /= static_cast<float>(input.buffer_length());
  }

  float spectral_profile_sum = 0.0f;
  for (int i = 0; i < input.channel_count(); ++i) {
    spectral_profile_sum += m_pSpectralProfile[i];
  }

  // Set the last component of the feature vector to be the log energy
  float logsum = log(spectral_profile_sum);
  if (!isinf(logsum)) {
    output_.set_sample(output_component_count_ - 1, 0, logsum);
  } else {
    output_.set_sample(output_component_count_ - 1, 0, -1000.0);
  }

  for (int ch = 0; ch < input.channel_count(); ++ch) {
    m_pSpectralProfile[ch] = pow(m_pSpectralProfile[ch], 0.8f);
  }

  RubberGMMCore(2, true);

  float mean1 = m_pMu[0];
  float mean2 = m_pMu[1];
  // LOG_INFO(_T("Orig. mean 0 = %f"), m_pMu[0]);
  // LOG_INFO(_T("Orig. mean 1 = %f"), m_pMu[1]);
  // LOG_INFO(_T("Orig. prob 0 = %f"), m_pA[0]);
  // LOG_INFO(_T("Orig. prob 1 = %f"), m_pA[1]);

  float a1 = 0.05 * m_pA[0];
  float a2 = 1.0 - 0.25 * m_pA[1];

  // LOG_INFO(_T("fA1 = %f"), fA1);
  // LOG_INFO(_T("fA2 = %f"), fA2);

  float gradient = (mean2 - mean1) / (a2 - a1);
  float intercept = mean2 - gradient * a2;

  // LOG_INFO(_T("fGradient = %f"), fGradient);
  // LOG_INFO(_T("fIntercept = %f"), fIntercept);

  for (int i = 0; i < m_iParamNComp; ++i) {
    m_pMu[i] = (static_cast<float>(i)
                / (static_cast<float>(m_iParamNComp) - 1.0f))
                * gradient + intercept;
                // LOG_INFO(_T("mean %d = %f"), i, m_pMu[i]);
  }

  for (int i = 0; i < m_iParamNComp; ++i) {
    m_pA[i] = 1.0f / static_cast<float>(m_iParamNComp);
  }

  RubberGMMCore(m_iParamNComp, false);

  // Amplitudes first
  for (int i = 0; i < m_iParamNComp - 1; ++i) {
    if (!isnan(m_pA[i])) {
      output_.set_sample(i, 0, m_pA[i]);
    } else {
      output_.set_sample(i, 0, 0.0f);
    }
  }

  // Then means if required
  if (output_positions_) {
    int idx = 0;
    for (int i = m_iParamNComp - 1; i < 2 * m_iParamNComp - 1; ++i) {
      if (!isnan(m_pMu[i])) {
        output_.set_sample(i, 0, m_pMu[idx]);
      } else {
        output_.set_sample(i, 0, 0.0f);
      }
      ++idx;
    }
  }

  PushOutput();
}

bool ModuleGaussians::RubberGMMCore(int iNComponents, bool bDoInit) {
  int iSizeX = m_iNumChannels;

  // Normalise the spectral profile
  float SpectralProfileTotal = 0.0f;
  for (int iCount = 0; iCount < iSizeX; iCount++) {
    SpectralProfileTotal += m_pSpectralProfile[iCount];
  }
  for (int iCount = 0; iCount < iSizeX; iCount++) {
    m_pSpectralProfile[iCount] /= SpectralProfileTotal;
  }

  if (bDoInit) {
    // Uniformly spaced components
    float dd = (iSizeX - 1.0f) / iNComponents;
    for (int i = 0; i < iNComponents; i++) {
      m_pMu[i] = dd / 2.0f + (i * dd);
      m_pA[i] = 1.0f / iNComponents;
    }
  }

  vector<float> pA_old;
  pA_old.resize(iNComponents);
  vector<float> pP_mod_X;
  pP_mod_X.resize(iSizeX);
  vector<float> pP_comp;
  pP_comp.resize(iSizeX * iNComponents);

  for (int iIteration = 0; iIteration < m_iParamMaxIt; iIteration++) {
    // (re)calculate posteriors (component probability given observation)
    // denominator: the model density at all observation points X
    for (int i = 0; i < iSizeX; ++i) {
      pP_mod_X[i] = 0.0f;
    }

    for (int c = 0; c < iNComponents; c++) {
      for (int iCount = 0; iCount < iSizeX; iCount++) {
        pP_mod_X[iCount] += 1.0f / sqrt(2.0f * M_PI * m_fParamVar)
                            * exp((-0.5f)
                            * pow(static_cast<float>(iCount+1) - m_pMu[c], 2)
                            / m_fParamVar) * m_pA[c];
      }
    }

    for (int i = 0; i < iSizeX * iNComponents; ++i) {
      pP_comp[i] = 0.0f;
    }

    for (int i = 0; i < iNComponents; i++) {
      for (int iCount = 0; iCount < iSizeX; iCount++) {
        pP_comp[iCount + i * iSizeX] =
          1.0f / sqrt(2.0f * M_PI * m_fParamVar)
          * exp((-0.5f) * pow((static_cast<float>(iCount + 1) - m_pMu[i]), 2)
          / m_fParamVar);
        pP_comp[iCount + i * iSizeX] =
          pP_comp[iCount + i * iSizeX] * m_pA[i] / pP_mod_X[iCount];
      }
    }

    for (int iCount = 0; iCount < iSizeX; ++iCount) {
      float fSum = 0.0f;
      for (int i = 0; i < iNComponents; ++i) {
        pP_comp[iCount+i*iSizeX] = pow(pP_comp[iCount + i * iSizeX],
                                       m_fParamPosteriorExp);  // expansion
        fSum += pP_comp[iCount+i*iSizeX];
      }
      for (int i = 0; i < iNComponents; ++i)
        pP_comp[iCount+i*iSizeX] = pP_comp[iCount + i * iSizeX] / fSum;
        // renormalisation
    }

    for (int i = 0; i < iNComponents; ++i) {
      pA_old[i] = m_pA[i];
      m_pA[i] = 0.0f;
      for (int iCount = 0; iCount < iSizeX; ++iCount) {
        m_pA[i] += pP_comp[iCount + i * iSizeX] * m_pSpectralProfile[iCount];
      }
    }

    // finish when already converged
    float fPrdist = 0.0f;
    for (int i = 0; i < iNComponents; ++i) {
      fPrdist += pow((m_pA[i] - pA_old[i]), 2);
    }
    fPrdist /= iNComponents;

    if (fPrdist < priors_converged_) {
      // LOG_INFO("Converged!");
      break;
    }
    // LOG_INFO("Didn't converge!");


    // update means (positions)
    for (int i = 0 ; i < iNComponents; ++i) {
      float mu_old = m_pMu[i];
      if (m_pA[i] > 0.0f) {
        m_pMu[i] = 0.0f;
        for (int iCount = 0; iCount < iSizeX; ++iCount) {
          m_pMu[i] += m_pSpectralProfile[iCount]
                      * pP_comp[iCount + i * iSizeX]
                      * static_cast<float>(iCount + 1);
        }
        m_pMu[i] /= m_pA[i];
        if (isnan(m_pMu[i])) {
          m_pMu[i] = mu_old;
        }
      }
    }
  }  // loop over iterations

  // Ensure they are sorted, using a really simple bubblesort
  bool bSorted = false;
  while (!bSorted) {
    bSorted = true;
    for (int i = 0; i < iNComponents - 1; ++i) {
      if (m_pMu[i] > m_pMu[i + 1]) {
        float fTemp = m_pMu[i];
        m_pMu[i] = m_pMu[i + 1];
        m_pMu[i + 1] = fTemp;
        fTemp = m_pA[i];
        m_pA[i] = m_pA[i + 1];
        m_pA[i + 1] = fTemp;
        bSorted = false;
      }
    }
  }
  return true;
}
}  // namespace aimc