view AutocorrelationProcessor.cpp @ 47:cb79f27f0748

Clamp cyclic tempogram min and max BPM to the BPM equivalents of the actual underlying min and max tempogram bins, rather than the "input" min and max BPM (fixed root cause of #1054)

/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */

/*
   Vamp Tempogram Plugin
   Carl Bussey, Centre for Digital Music, Queen Mary University of London
   Copyright 2014 Queen Mary University of London.
    
   This program is free software; you can redistribute it and/or
   modify it under the terms of the GNU General Public License as
   published by the Free Software Foundation; either version 2 of the
   License, or (at your option) any later version.  See the file
   COPYING included with this distribution for more information.
*/

#include "AutocorrelationProcessor.h"
using namespace std;
#include <iostream>

AutocorrelationProcessor::AutocorrelationProcessor(int windowLength, int hopSize) :
    m_windowLength(windowLength),
    m_hopSize(hopSize)
{

}

AutocorrelationProcessor::~AutocorrelationProcessor()
{

}

AutoCorrelation AutocorrelationProcessor::process(float * input, int inputLength) const
{
    int readBlockPointerIndex = 0;
    AutoCorrelation autocorrelation;
    
    while(readBlockPointerIndex <= inputLength) {
        
        vector<float> autocorrelationBlock;
        
        for (int lag = 0; lag < m_windowLength; lag++){
            float sum = 0;
            int readPointer = readBlockPointerIndex - m_windowLength/2;
            
            for (int n = 0; n < (int)m_windowLength; n++){
                if (readPointer+lag >= inputLength) break;
                else if (readPointer >= 0) {
		    sum += input[readPointer]*input[readPointer+lag];
		}
                readPointer++;
            }
            autocorrelationBlock.push_back(sum/(2*m_windowLength + 1 - lag));
        }
        
        autocorrelation.push_back(autocorrelationBlock);
        readBlockPointerIndex += m_hopSize;
    }
    
    return autocorrelation;
}