comparison Spectrogram.cpp @ 7:21147df9cb2d

* Error when deleting Spectrogram object in Tempogram::getRemainingFeatures().
* Moved Spectrogram computation into own class.

+//
+//  Spectrogram.cpp
+//  Tempogram
+//
+//  Created by Carl Bussey on 07/08/2014.
+//  Copyright (c) 2014 Carl Bussey. All rights reserved.
+//
+
+#include "Spectrogram.h"
+#include <iostream>
+using namespace std;
+using Vamp::FFT;
+
+Spectrogram::Spectrogram(unsigned int inputLength, unsigned int fftLength, unsigned int hopSize) :
+    m_inputLength(inputLength),
+    m_fftLength(fftLength),
+    m_hopSize(hopSize),
+    m_numberOfOutputBins(floor(fftLength/2 + 0.5) + 1),
+    fftInput(NULL),
+    fftOutputReal(NULL),
+    fftOutputImag(NULL)
+{
+    initialise();
+}
+
+Spectrogram::~Spectrogram(){
+    cleanup();
+}
+
+void Spectrogram::initialise(){
+    fftInput = new double [m_fftLength];
+    fftOutputReal = new double [m_fftLength];
+    fftOutputImag = new double [m_fftLength];
+    
+    int numberOfBlocks = ceil(m_inputLength/m_hopSize) + m_fftLength/m_hopSize-1;
+    spectrogramOutput = vector< vector<float> >(m_numberOfOutputBins, vector<float>(numberOfBlocks));
+}
+
+void Spectrogram::cleanup(){
+    delete []fftInput;
+    delete []fftOutputReal;
+    delete []fftOutputImag;
+    
+    fftInput = fftOutputReal = fftOutputImag = NULL;
+    
+    cerr << "Spectrogram" << endl;
+}
+
+vector< vector<float> > Spectrogram::audioToMagnitudeSpectrogram(const float * const input, const float * window){
+    
+    int readPointerBeginIndex = m_hopSize-m_fftLength;
+    int writeBlockPointer = 0;
+    
+    while(readPointerBeginIndex < m_inputLength){
+        
+        int readPointer = readPointerBeginIndex;
+        for (int n = 0; n < m_fftLength; n++){
+            if(readPointer < 0 || readPointer >= m_inputLength){
+                fftInput[n] = 0.0; //pad with zeros
+            }
+            else{
+                fftInput[n] = input[readPointer] * window[n];
+            }
+            readPointer++;
+        }
+        
+        FFT::forward(m_fftLength, fftInput, NULL, fftOutputReal, fftOutputImag);
+        
+        //@todo: sample at logarithmic spacing? Leave for host?
+        for(int k = 0; k < m_numberOfOutputBins; k++){
+            spectrogramOutput[k][writeBlockPointer] = (fftOutputReal[k]*fftOutputReal[k] + fftOutputImag[k]*fftOutputImag[k]); //Magnitude or power?
+        }
+        
+        readPointerBeginIndex += m_hopSize;
+        writeBlockPointer++;
+    }
+    
+    return spectrogramOutput;
+}