c@7: //
c@7: //  Spectrogram.cpp
c@7: //  Tempogram
c@7: //
c@7: //  Created by Carl Bussey on 07/08/2014.
c@7: //  Copyright (c) 2014 Carl Bussey. All rights reserved.
c@7: //
c@7: 
c@7: #include "Spectrogram.h"
c@7: using namespace std;
c@7: using Vamp::FFT;
c@13: #include <iostream>
c@7: 
c@13: SpectrogramProcessor::SpectrogramProcessor(const size_t &inputLength, const size_t &windowLength, const size_t &fftLength, const size_t &hopSize) :
c@7:     m_inputLength(inputLength),
c@9:     m_windowLength(windowLength),
c@7:     m_fftLength(fftLength),
c@7:     m_hopSize(hopSize),
c@8:     m_numberOfOutputBins(ceil(fftLength/2) + 1),
c@13:     m_pFftInput(0),
c@13:     m_pFftOutputReal(0),
c@13:     m_pFftOutputImag(0)
c@7: {
c@7:     initialise();
c@7: }
c@7: 
c@11: SpectrogramProcessor::~SpectrogramProcessor(){
c@7:     cleanup();
c@7: }
c@7: 
c@11: void SpectrogramProcessor::initialise(){
c@13:     m_pFftInput = new double [m_fftLength];
c@13:     m_pFftOutputReal = new double [m_fftLength];
c@13:     m_pFftOutputImag = new double [m_fftLength];
c@7: }
c@7: 
c@11: void SpectrogramProcessor::cleanup(){
c@13:     delete []m_pFftInput;
c@13:     delete []m_pFftOutputReal;
c@13:     delete []m_pFftOutputImag;
c@7:     
c@13:     m_pFftInput = m_pFftOutputReal = m_pFftOutputImag = 0;
c@7: }
c@7: 
c@9: //process method
c@13: Spectrogram SpectrogramProcessor::process(const float * const pInput, const float * pWindow) const
c@13: {
c@13:     int numberOfBlocks = ceil(m_inputLength/m_hopSize) + 2*(ceil(m_windowLength/m_hopSize)-1); //The last term corresponds to overlaps at the beginning and end with padded zeros. I.e., if m_hopSize = m_windowLength/2, there'll be 1 overlap at each end. If m_hopSize = m_windowLength/4, there'll be 3 overlaps at each end, etc...
c@13:     Spectrogram spectrogram(m_numberOfOutputBins, vector<float>(numberOfBlocks));
c@7:     
c@9:     int readPointerBeginIndex = m_hopSize-m_windowLength;
c@13:     unsigned int writeBlockPointer = 0;
c@7:     
c@13:     while(readPointerBeginIndex < (int)m_inputLength){
c@7:         
c@7:         int readPointer = readPointerBeginIndex;
c@13:         for (unsigned int n = 0; n < m_windowLength; n++){
c@13:             if(readPointer < 0 || readPointer >= (int)m_inputLength){
c@13:                 m_pFftInput[n] = 0.0; //pad with zeros
c@7:             }
c@7:             else{
c@13:                 m_pFftInput[n] = pInput[readPointer] * pWindow[n];
c@7:             }
c@7:             readPointer++;
c@7:         }
c@13:         for (unsigned int n = m_windowLength; n < m_fftLength; n++){
c@13:             m_pFftInput[n] = 0.0;
c@9:         }
c@7:         
c@13:         FFT::forward(m_fftLength, m_pFftInput, 0, m_pFftOutputReal, m_pFftOutputImag);
c@7:         
c@7:         //@todo: sample at logarithmic spacing? Leave for host?
c@13:         for(unsigned int k = 0; k < m_numberOfOutputBins; k++){
c@13:             spectrogram[k][writeBlockPointer] = (m_pFftOutputReal[k]*m_pFftOutputReal[k] + m_pFftOutputImag[k]*m_pFftOutputImag[k]); //Magnitude or power?
c@13:             //std::cout << spectrogram[k][writeBlockPointer] << std::endl;
c@7:         }
c@7:         
c@7:         readPointerBeginIndex += m_hopSize;
c@7:         writeBlockPointer++;
c@7:     }
c@7:     
c@13:     return spectrogram;
Chris@10: }