changeset 37:47d5321a57c2

Fix downsampling: correct window to match MATLAB implementation, apply re-normalisation

--- a/src/FeatureDownsample.cpp	Thu Oct 01 09:28:38 2015 +0100
+++ b/src/FeatureDownsample.cpp	Thu Oct 01 11:21:37 2015 +0100
@@ -4,6 +4,7 @@
 
 #include "Filter.h"
 #include "Window.h"
+#include "Normalise.h"
 
 #include <stdexcept>
 
@@ -19,9 +20,9 @@
 
     // Our windows are periodic rather than symmetric, but we want a
     // symmetric window here
-    Window<double> w(HanningWindow, params.windowLength - 1);
-    vector<double> wd(w.getWindowData());
-    wd.push_back(wd[0]);
+    Window<double> w(HanningWindow, params.windowLength + 1);
+    vector<double> wdat(w.getWindowData());;
+    vector<double> wd(wdat.begin()+1, wdat.end());
 
     double divisor = 0.0;
     for (auto x: wd) divisor += x;
@@ -73,7 +74,8 @@
 	    }
 	}
 	if (m_toNext == 0) {
-	    out.push_back(outcol);
+	    out.push_back(Normalise::normalise
+			  (outcol, m_params.normP, m_params.normThresh));
 	    m_toNext = m_params.downsampleFactor;
 	    ++m_outCount;
 	}
@@ -93,7 +95,8 @@
     for (int i = 0;
 	 m_outCount < expected && i < int(tail.size());
 	 ++i, ++m_outCount) {
-	out.push_back(tail[i]);
+	out.push_back(Normalise::normalise
+		      (tail[i], m_params.normP, m_params.normThresh));
     }
     return out;
 }

--- a/src/FeatureDownsample.h	Thu Oct 01 09:28:38 2015 +0100
+++ b/src/FeatureDownsample.h	Thu Oct 01 11:21:37 2015 +0100
@@ -18,10 +18,14 @@
 	int featureSize;
 	int downsampleFactor;
 	int windowLength;
+        int normP; // 0 = no normalisation, 1 = L^1, 2 = L^2
+        double normThresh;
 	Parameters() :
 	    featureSize(1),
 	    downsampleFactor(10),
-	    windowLength(41)
+	    windowLength(41),
+	    normP(2),
+	    normThresh(1e-6)
 	{ }
     };
 

--- a/src/TipicVampPlugin.cpp	Thu Oct 01 09:28:38 2015 +0100
+++ b/src/TipicVampPlugin.cpp	Thu Oct 01 11:21:37 2015 +0100
@@ -217,7 +217,7 @@
     d.sampleRate /= 10.0;
     list.push_back(d);
     
-    d.identifier = "cp";
+    d.identifier = "chroma";
     d.name = "Chroma Pitch Features";
     d.description = "";
     d.unit = "";
@@ -375,7 +375,7 @@
 	v_convert(f.values.data(), block[i].data(), h);
 	fs[outputNo].push_back(f);
     }
-
+    
     if (m_downsamplers.find(outputNo) == m_downsamplers.end()) {
 	FeatureDownsample::Parameters params;
 	params.featureSize = block[0].size();