diff Spectrogram.cpp @ 9:be59b4a73f49

* Added Spectrogram zero padding functionality
* Made output bins correspond to BPM
* User can now specify a range of output bins to view
* Comments added

--- a/Spectrogram.cpp	Thu Aug 07 17:25:24 2014 +0100
+++ b/Spectrogram.cpp	Tue Aug 12 14:40:37 2014 +0100
@@ -7,12 +7,12 @@
 //
 
 #include "Spectrogram.h"
-#include <iostream>
 using namespace std;
 using Vamp::FFT;
 
-Spectrogram::Spectrogram(unsigned int inputLength, unsigned int fftLength, unsigned int hopSize) :
+Spectrogram::Spectrogram(unsigned int inputLength, unsigned int windowLength, unsigned int fftLength, unsigned int hopSize) :
     m_inputLength(inputLength),
+    m_windowLength(windowLength),
     m_fftLength(fftLength),
     m_hopSize(hopSize),
     m_numberOfOutputBins(ceil(fftLength/2) + 1),
@@ -32,7 +32,7 @@
     fftOutputReal = new double [m_fftLength];
     fftOutputImag = new double [m_fftLength];
     
-    int numberOfBlocks = ceil(m_inputLength/m_hopSize) + 2*(ceil(m_fftLength/m_hopSize)-1); //The last term corresponds to overlaps at the beginning and end with padded zeros. I.e., if m_hopSize = m_fftLength/2, there'll be 1 overlap at each end. If m_hopSize = m_fftLength/4, there'll be 3 overlaps at each end, etc...
+    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...
     spectrogramOutput = vector< vector<float> >(m_numberOfOutputBins, vector<float>(numberOfBlocks));
 }
 
@@ -44,15 +44,16 @@
     fftInput = fftOutputReal = fftOutputImag = NULL;
 }
 
+//process method
 vector< vector<float> > Spectrogram::audioToMagnitudeSpectrogram(const float * const input, const float * window){
     
-    int readPointerBeginIndex = m_hopSize-m_fftLength;
+    int readPointerBeginIndex = m_hopSize-m_windowLength;
     int writeBlockPointer = 0;
     
     while(readPointerBeginIndex < m_inputLength){
         
         int readPointer = readPointerBeginIndex;
-        for (int n = 0; n < m_fftLength; n++){
+        for (int n = 0; n < m_windowLength; n++){
             if(readPointer < 0 || readPointer >= m_inputLength){
                 fftInput[n] = 0.0; //pad with zeros
             }
@@ -61,13 +62,15 @@
             }
             readPointer++;
         }
+        for (int n = m_windowLength; n < m_fftLength; n++){
+            fftInput[n] = 0.0;
+        }
         
         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?
-            cerr << writeBlockPointer << " : " << spectrogramOutput[k].size() << endl;
         }
         
         readPointerBeginIndex += m_hopSize;