c@25: //
c@25: //  AutocorrelationProcessor.cpp
c@25: //  Tempogram
c@25: //
c@25: //  Created by Carl Bussey on 20/08/2014.
c@25: //  Copyright (c) 2014 Carl Bussey. All rights reserved.
c@25: //
c@25: 
c@25: #include "AutocorrelationProcessor.h"
c@25: using namespace std;
c@25: 
c@26: AutocorrelationProcessor::AutocorrelationProcessor(const size_t &windowLength, const unsigned int &hopSize) :
c@25:     m_windowLength(windowLength),
c@25:     m_hopSize(hopSize),
c@26:     m_blockInput(0)
c@25: {
c@26:     m_blockInput = new float [m_windowLength];
c@26: }
c@26: 
c@26: AutocorrelationProcessor::~AutocorrelationProcessor(){
c@26:     delete []m_blockInput;
c@26:     m_blockInput = 0;
c@25: }
c@25: 
c@25: AutoCorrelation AutocorrelationProcessor::process(float * input, const size_t &inputLength) const
c@25: {
c@25:     int readBlockPointerIndex = 0;
c@25:     AutoCorrelation autocorrelation;
c@25:     
c@25:     while(readBlockPointerIndex <= (int)inputLength) {
c@26:         int readPointer = readBlockPointerIndex - m_windowLength/2; //read window centered at readBlockPointerIndex
c@25:         
c@26:         for (int n = 0; n < (int)m_windowLength; n++){
c@26:             if (readPointer < 0 || readPointer >= (int)inputLength) m_blockInput[n] = 0.0f;
c@26:             else m_blockInput[n] = input[readPointer];
c@26:             
c@26:             readPointer++;
c@26:         }
c@26:         
c@26:         autocorrelation.push_back(processBlock());
c@25:         readBlockPointerIndex += m_hopSize;
c@25:     }
c@25:     
c@25:     return autocorrelation;
c@25: }
c@25: 
c@26: vector<float> AutocorrelationProcessor::processBlock() const
c@25: {
c@25:     vector<float> autocorrelation;
c@25:     
c@25:     int N = m_windowLength/m_lagIncrement;
c@25:     
c@25:     for (int lag = 0; lag < N; lag++){
c@25:         float sum = 0;
c@26: 
c@26:         for (int n = 0; n < (int)m_windowLength-lag; n++){
c@26:             sum += m_blockInput[lag]*m_blockInput[n+lag];
c@25:         }
c@25:         autocorrelation.push_back(sum/(2*N + 1 - lag));
c@25:     }
c@25:     
c@25:     return autocorrelation;
c@25: }