diff dsp/chromagram/ChromaProcess.cpp @ 225:49844bc8a895

* Queen Mary C++ DSP library

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dsp/chromagram/ChromaProcess.cpp	Wed Apr 05 17:35:59 2006 +0000
@@ -0,0 +1,213 @@
+/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
+
+/*
+    QM DSP Library
+
+    Centre for Digital Music, Queen Mary, University of London.
+    This file copyright 2005-2006 Christian Landone.
+    All rights reserved.
+*/
+
+
+#include "ChromaProcess.h"
+#include "dsp/maths/Histogram.h"
+#include <math.h>
+//////////////////////////////////////////////////////////////////////
+// Construction/Destruction
+//////////////////////////////////////////////////////////////////////
+
+ChromaProcess::ChromaProcess()
+{
+
+}
+
+ChromaProcess::~ChromaProcess()
+{
+
+}
+
+int ChromaProcess::findChromaBias( vector<double> chromaVector, unsigned int BPO, unsigned int frames )
+{
+    vector<double> newChroma;
+    vector<int> peakIndex;
+    vector<int> modPeakIndex;
+
+    unsigned int chromaLength = chromaVector.size(); 
+
+    unsigned int newLength = chromaLength + (2*BPO);
+
+    newChroma.resize( newLength );
+    newChroma.clear();
+
+    modPeakIndex.resize( newLength );
+    modPeakIndex.clear();
+
+    //adds last row at the top and first row at the bottom to create 
+    //circularity - effectively adds 2 to the bpo-length of the vectors:
+
+    for( unsigned int i = 0; i < BPO; i++ )
+    {
+	newChroma.push_back( chromaVector[ chromaLength - BPO + i ] );
+    }
+
+    for( unsigned i = 0; i < chromaLength; i++ )
+    {
+	newChroma.push_back( chromaVector[ i ] );
+    }
+
+    for( unsigned i = 0; i < BPO; i++ )
+    {
+	newChroma.push_back( chromaVector[ i ] );
+    }
+
+    // pick peaks in the chroma
+    peakIndex = getPeaks( newChroma, BPO );
+
+    // modularises to res = bpo/12 bins:
+    // corrects the mod value for bin 3
+    modPeakIndex = mod( peakIndex, 3 );
+
+    // finds the highest concentration of peaks on the bpo/12 bin resolution
+    THistogram<int> m_hist(3);
+
+    double ave, adev, sdev, var, skew, ccurt;
+
+    m_hist.compute(modPeakIndex);
+
+    m_hist.getMoments( modPeakIndex, ave, adev, sdev, var, skew, ccurt );
+
+    vector <double> histogram = m_hist.geTHistogramD();
+    //////////////////////////////////////////////////////////////////////////////
+
+    ///////////////////////////////////////////////////////////////////////////
+	// Find actual bias from histogram
+	int minIdx, maxIdx;
+	double min, max;
+
+	findHistMaxMin( histogram, &max, &maxIdx, &min, &minIdx );
+
+/*
+  FILE* foutchroma = fopen("../testdata/newchroma.bin","wb");
+  FILE* foutpeaks = fopen("../testdata/peaks.bin","wb");
+
+
+  fwrite( &chromaVector[0], sizeof(double), chromaVector.size(), foutchroma );
+  fwrite( &histogram[0], sizeof(double), histogram.size(), foutpeaks );
+
+  fclose( foutchroma );
+  fclose( foutpeaks );
+*/
+	return maxIdx - 1;
+}
+
+
+vector <int> ChromaProcess::getPeaks(vector <double> chroma, unsigned int BPO)
+{
+    vector <int> peaks;
+	
+    double pre = 0;
+    double post = 0;
+    double current = 0;
+
+    unsigned int BPOCounter = 0;
+    unsigned int mult = 0;
+    unsigned int idx = 0;
+
+    for( unsigned int i = 0; i < chroma.size() - 0; i++ )
+    {
+	BPOCounter++;
+
+	pre = chroma[ i ];
+	current = chroma[ i + 1 ];
+	post = chroma[ i + 2 ];
+		
+	if( (current > 0) && (current > pre) && (current > post) )
+	{
+	    peaks.push_back( BPOCounter + 1);
+	}
+
+		
+	if( BPOCounter == (BPO - 2 ) )
+	{
+	    BPOCounter = 0;
+	    i+=2;
+	}
+		
+    }
+
+    /*
+      for( unsigned int i = 1; i < chroma.size() - 1; i++ )
+      {
+      BPOCounter++ ;
+
+      pre = chroma[ i - 1 ];
+      current = chroma[ i ];
+      post = chroma[ i + 1 ];
+		
+      if( (current > 0) && (current > pre) && (current > post) )
+      {
+      peaks.push_back( BPOCounter + 1 );
+      }
+
+      if( BPOCounter == (PO - 1) )
+      {
+      BPOCounter = 1;
+      i+=2;
+      }
+      }
+    */
+    return peaks;
+}
+
+vector <int> ChromaProcess::mod(vector <int> input, int res)
+{
+    vector <int> result;
+
+    for( unsigned int i = 0; i < input.size(); i++ )
+    {
+	int val = input[ i ];
+	int res = val - res * floor( (double)val / (double)res );
+
+	if( val != 0 )
+	{
+	    if( res == 0 )
+		res = 3;
+
+	    result.push_back( res );
+	}
+	else
+	{
+	    result.push_back( val );
+	}
+    }
+    return result;
+}
+
+void ChromaProcess::findHistMaxMin( vector<double> hist, double* max, int* maxIdx, double* min, int* minIdx )
+{
+    double temp = 0.0;
+    unsigned int vecLength = hist.size();
+
+    *minIdx = 0;
+    *maxIdx = 0;
+
+    *min = hist[0];
+    *max = *min;
+
+    for( unsigned int u = 0; u < vecLength; u++ )
+    {
+	temp = hist[ u ];
+
+	if( temp < *min )
+	{
+	    *min =  temp ;
+	    *minIdx = u;
+	}
+	if( temp > *max )
+	{
+	    *max =  temp ;
+	    *maxIdx = u;
+	}
+
+    }
+}