content: /*  DurationFeatureExtractor.java
  
      Copyright (c) 2009-2014 Andrew Rosenberg
  
    This file is part of the AuToBI prosodic analysis package.
  
    AuToBI is free software: you can redistribute it and/or modify
    it under the terms of the Apache License (see boilerplate below)
  
   ***********************************************************************************************************************
   *
   * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
   * the License. You should have received a copy of the Apache 2.0 License along with AuToBI.
   * 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.
   *
   ***********************************************************************************************************************
   */
  package edu.cuny.qc.speech.AuToBI.featureextractor;
  
  import edu.cuny.qc.speech.AuToBI.core.FeatureExtractor;
  import edu.cuny.qc.speech.AuToBI.core.Region;
  import edu.cuny.qc.speech.AuToBI.util.AuToBIUtils;
  
  import java.util.List;
  
  /**
   * DurationFeatureExtractor extracts features related to the length of the regions.
   * <p/>
   * The extracted features include the duration in seconds, the duration normalized by the duration of surrounding words,
   * and the length and presence of any following silences.
   * <p/>
   * TODO: This behavior should almost certainly be refactored into a broader set of feature extractors
   */
  public class DurationFeatureExtractor extends FeatureExtractor {
    public static final String moniker = "duration,prevPause,follPause,nominal_followsSilence,nominal_precedesSilence";
  
    // Gaps between regions greater than this length are considered silent.
    private static final Double SILENCE_THRESHOLD = 0.01;
  
    /**
     * Constructs a DurationFeatureExtractor.
     */
    public DurationFeatureExtractor() {
      super();
      extracted_features.add("duration");
      extracted_features.add("prevPause");
      extracted_features.add("follPause");
      extracted_features.add("nominal_followsSilence");
      extracted_features.add("nominal_precedesSilence");
    }
  
    /**
     * Extracts duration features from the data points.
     *
     * @param data_points the data points
     * @throws FeatureExtractorException if the regions overlap
     */
    public void extractFeatures(List data_points) throws FeatureExtractorException {
  
      Double previous_pause;
      Double following_pause;
      Double max_pauselen = 120.0;
      Double epsilon = 0.001;
      for (int i = 0; i < data_points.size(); ++i) {
        if (i < data_points.size() - 1) {
          following_pause = Math.min(max_pauselen, ((Region) data_points.get(i + 1)).getStart() -
              ((Region) data_points.get(i)).getEnd());
        } else {
          following_pause = max_pauselen;
        }
        if (i > 0) {
          previous_pause = Math.min(max_pauselen, ((Region) data_points.get(i)).getStart() -
              ((Region) data_points.get(i - 1)).getEnd());
        } else {
          previous_pause = max_pauselen;
        }
        if (previous_pause < 0.0) {
          if (previous_pause > -epsilon) {
            previous_pause = 0.0;
          } else {
            AuToBIUtils.warn(
                "Invalid previous pause value on word: " + data_points.get(i).toString());
          }
        }
  
        if (following_pause < 0.0) {
          if (following_pause > -epsilon) {
            following_pause = 0.0;
          } else {
            AuToBIUtils.warn(
                "Invalid following pause value on word: " + data_points.get(i).toString());
          }
        }
  
        Region region = (Region) data_points.get(i);
  
        region.setAttribute("duration", (region.getEnd() - region.getStart()));
        region.setAttribute("prevPause", previous_pause);
        region.setAttribute("follPause", following_pause);
        if (following_pause > SILENCE_THRESHOLD) {
          region.setAttribute("nominal_precedesSilence", "TRUE");
        } else {
          region.setAttribute("nominal_precedesSilence", "FALSE");
        }
        if (previous_pause > SILENCE_THRESHOLD) {
          region.setAttribute("nominal_followsSilence", "TRUE");
        } else {
          region.setAttribute("nominal_followsSilence", "FALSE");
        }
      }
    }
  }
  