# HG changeset patch
# User Chris Cannam
# Date 1347377867 -3600
# Node ID f72a470fe4b543d25d24209923c95c02d18adaf1
# Parent  c666067fb8dadbce6da15932946d9fc4aeefe997
Pull out mean filter, test it

diff -r c666067fb8da -r f72a470fe4b5 CepstralPitchTracker.cpp
--- a/CepstralPitchTracker.cpp	Wed Aug 15 14:53:28 2012 +0100
+++ b/CepstralPitchTracker.cpp	Tue Sep 11 16:37:47 2012 +0100
@@ -23,6 +23,7 @@
 */
 
 #include "CepstralPitchTracker.h"
+#include "MeanFilter.h"
 
 #include "vamp-sdk/FFT.h"
 
@@ -256,24 +257,6 @@
     fs[1].push_back(nf);
 }
 
-void
-CepstralPitchTracker::filter(const double *cep, double *data)
-{
-    for (int i = 0; i < m_bins; ++i) {
-        double v = 0;
-        int n = 0;
-        // average according to the vertical filter length
-        for (int j = -m_vflen/2; j <= m_vflen/2; ++j) {
-            int ix = i + m_binFrom + j;
-            if (ix >= 0 && ix < (int)m_blockSize) {
-                v += cep[ix];
-                ++n;
-            }
-        }
-        data[i] = v / n;
-    }
-}
-
 double
 CepstralPitchTracker::cubicInterpolate(const double y[4], double x)
 {
@@ -380,7 +363,7 @@
 
     int n = m_bins;
     double *data = new double[n];
-    filter(rawcep, data);
+    MeanFilter(m_vflen).filterSubsequence(rawcep, data, m_blockSize, n, m_binFrom);
     delete[] rawcep;
 
     double maxval = 0.0;
diff -r c666067fb8da -r f72a470fe4b5 Makefile.inc
--- a/Makefile.inc	Wed Aug 15 14:53:28 2012 +0100
+++ b/Makefile.inc	Tue Sep 11 16:37:47 2012 +0100
@@ -14,6 +14,7 @@
 PLUGIN := cepstral-pitchtracker$(PLUGIN_EXT)
 
 HEADERS := CepstralPitchTracker.h \
+           MeanFilter.h \
 	   NoteHypothesis.h \
 	   PeakInterpolator.h
 
@@ -24,6 +25,7 @@
 PLUGIN_MAIN := libmain.cpp
 
 TESTS := test/test-notehypothesis \
+         test/test-meanfilter \
          test/test-peakinterpolator
 
 OBJECTS := $(SOURCES:.cpp=.o)
@@ -40,6 +42,9 @@
 test/test-notehypothesis: test/TestNoteHypothesis.o $(OBJECTS)
 	$(CXX) -o $@ $^ $(TEST_LDFLAGS)
 
+test/test-meanfilter: test/TestMeanFilter.o $(OBJECTS)
+	$(CXX) -o $@ $^ $(TEST_LDFLAGS)
+
 test/test-peakinterpolator: test/TestPeakInterpolator.o $(OBJECTS)
 	$(CXX) -o $@ $^ $(TEST_LDFLAGS)
 
diff -r c666067fb8da -r f72a470fe4b5 MeanFilter.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MeanFilter.h	Tue Sep 11 16:37:47 2012 +0100
@@ -0,0 +1,73 @@
+/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
+/*
+    This file is Copyright (c) 2012 Chris Cannam
+  
+    Permission is hereby granted, free of charge, to any person
+    obtaining a copy of this software and associated documentation
+    files (the "Software"), to deal in the Software without
+    restriction, including without limitation the rights to use, copy,
+    modify, merge, publish, distribute, sublicense, and/or sell copies
+    of the Software, and to permit persons to whom the Software is
+    furnished to do so, subject to the following conditions:
+
+    The above copyright notice and this permission notice shall be
+    included in all copies or substantial portions of the Software.
+
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+    EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+    MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+    NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR
+    ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
+    CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+    WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+*/
+
+#ifndef _MEAN_FILTER_H_
+#define _MEAN_FILTER_H_
+
+class MeanFilter
+{
+public:
+    /**
+     * Construct a non-causal mean filter with filter length flen,
+     * that replaces each sample N with the mean of samples
+     * [N-floor(F/2) .. N+floor(F/2)] where F is the filter length.
+     * Only odd F are supported.
+     */
+    MeanFilter(int flen) : m_flen(flen) { }
+    ~MeanFilter() { }
+
+    /**
+     * Filter the n samples in "in" and place the results in "out"
+     */
+    void filter(const double *in, double *out, const int n) {
+	filterSubsequence(in, out, n, n, 0);
+    }
+
+    /**
+     * Filter the n samples starting at the given offset in the
+     * m-element array "in" and place the results in "out"
+     */
+    void filterSubsequence(const double *in, double *out,
+			   const int m, const int n,
+			   const int offset) {
+	int half = m_flen/2;
+	for (int i = 0; i < n; ++i) {
+	    double v = 0;
+	    int n = 0;
+	    for (int j = -half; j <= half; ++j) {
+		int ix = i + j + offset;
+		if (ix >= 0 && ix < m) {
+		    v += in[ix];
+		    ++n;
+		}
+	    }
+	    out[i] = v / n;
+	}
+    }
+
+private:
+    int m_flen;
+};
+
+#endif
diff -r c666067fb8da -r f72a470fe4b5 test/TestMeanFilter.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/TestMeanFilter.cpp	Tue Sep 11 16:37:47 2012 +0100
@@ -0,0 +1,91 @@
+/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
+/*
+    This file is Copyright (c) 2012 Chris Cannam
+  
+    Permission is hereby granted, free of charge, to any person
+    obtaining a copy of this software and associated documentation
+    files (the "Software"), to deal in the Software without
+    restriction, including without limitation the rights to use, copy,
+    modify, merge, publish, distribute, sublicense, and/or sell copies
+    of the Software, and to permit persons to whom the Software is
+    furnished to do so, subject to the following conditions:
+
+    The above copyright notice and this permission notice shall be
+    included in all copies or substantial portions of the Software.
+
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+    EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+    MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+    NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR
+    ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
+    CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+    WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+*/
+
+#include "MeanFilter.h"
+
+#define BOOST_TEST_DYN_LINK
+#define BOOST_TEST_MAIN
+
+#include <boost/test/unit_test.hpp>
+
+BOOST_AUTO_TEST_SUITE(TestMeanFilter)
+
+BOOST_AUTO_TEST_CASE(simpleFilter)
+{
+    double in[] = { 1.0, 2.0, 3.0 };
+    double out[3];
+    MeanFilter(3).filter(in, out, 3);
+    BOOST_CHECK_EQUAL(out[0], 1.5);
+    BOOST_CHECK_EQUAL(out[1], 2.0);
+    BOOST_CHECK_EQUAL(out[2], 2.5);
+}
+
+BOOST_AUTO_TEST_CASE(simpleSubset)
+{
+    double in[] = { 1.0, 2.0, 3.0, 4.0, 5.0 };
+    double out[3];
+    MeanFilter(3).filterSubsequence(in, out, 5, 3, 1);
+    BOOST_CHECK_EQUAL(out[0], 2.0);
+    BOOST_CHECK_EQUAL(out[1], 3.0);
+    BOOST_CHECK_EQUAL(out[2], 4.0);
+}
+
+BOOST_AUTO_TEST_CASE(flenExceedsArraySize)
+{
+    double in[] = { 1.0, 2.0, 3.0 };
+    double out[3];
+    MeanFilter(5).filter(in, out, 3);
+    BOOST_CHECK_EQUAL(out[0], 2.0);
+    BOOST_CHECK_EQUAL(out[1], 2.0);
+    BOOST_CHECK_EQUAL(out[2], 2.0);
+}
+
+BOOST_AUTO_TEST_CASE(flenIs1)
+{
+    double in[] = { 1.0, 2.0, 3.0 };
+    double out[3];
+    MeanFilter(1).filter(in, out, 3);
+    BOOST_CHECK_EQUAL(out[0], in[0]);
+    BOOST_CHECK_EQUAL(out[1], in[1]);
+    BOOST_CHECK_EQUAL(out[2], in[2]);
+}
+
+BOOST_AUTO_TEST_CASE(arraySizeIs1)
+{
+    double in[] = { 1.0 };
+    double out[1];
+    MeanFilter(3).filter(in, out, 1);
+    BOOST_CHECK_EQUAL(out[0], in[0]);
+}
+
+BOOST_AUTO_TEST_CASE(subsequenceLengthIs1)
+{
+    double in[] = { 1.0, 2.0, 3.0 };
+    double out[1];
+    MeanFilter(3).filterSubsequence(in, out, 3, 1, 2);
+    BOOST_CHECK_EQUAL(out[0], 2.5);
+}
+
+BOOST_AUTO_TEST_SUITE_END()
+