Rather than using trough picker, make the division frequencies drift downhill

src/finer/Guide.h

@@ -137,15 +137,14 @@ public:
         return m_configuration;
     }
     
-    void calculate(double ratio,
-                   const double *const magnitudes,
-                   const int *const troughs,
-                   const double *const prevMagnitudes,
-                   const BinSegmenter::Segmentation &segmentation,
-                   const BinSegmenter::Segmentation &prevSegmentation,
-                   const BinSegmenter::Segmentation &nextSegmentation,
-                   bool specialCaseUnity,
-                   Guidance &guidance) const {
+    void updateGuidance(double ratio,
+                        const double *const magnitudes,
+                        const double *const prevMagnitudes,
+                        const BinSegmenter::Segmentation &segmentation,
+                        const BinSegmenter::Segmentation &prevSegmentation,
+                        const BinSegmenter::Segmentation &nextSegmentation,
+                        bool specialCaseUnity,
+                        Guidance &guidance) const {
 
         guidance.kick.present = false;
         guidance.lowPercussive.present = false;
@@ -221,8 +220,20 @@ public:
         double lower = snapToTrough(m_defaultLower, troughs);
         if (lower > m_maxLower) lower = m_maxLower;
 */
-/*
+        double prevLower = guidance.fftBands[0].f1;
+        double lower = descendToValley(prevLower, magnitudes);
+        if (lower > m_maxLower || lower < m_minLower) {
+            lower = m_defaultLower;
+        }
+        
         double prevHigher = guidance.fftBands[1].f1;
+        double higher = descendToValley(prevHigher, magnitudes);
+        if (higher > m_maxHigher || higher < m_minHigher) {
+            higher = m_defaultHigher;
+        }
+
+
+/*
         double higher = snapToTrough(prevHigher, troughs, magnitudes);
         if (higher < m_minHigher || higher > m_maxHigher) {
             higher = snapToTrough(m_defaultHigher, troughs, magnitudes);
@@ -231,17 +242,16 @@ public:
             }
         }
 */
+        /*
         double higher = m_defaultHigher;
         
-        double prevLower = guidance.fftBands[0].f1;
-        double lower = snapToTrough(prevLower, troughs, magnitudes);
         if (lower < m_minLower || lower > m_maxLower) {
             lower = snapToTrough(m_defaultLower, troughs, magnitudes);
             if (lower < m_minLower || lower > m_maxLower) {
                 lower = prevLower;
             }
         }
-        
+        */        
         guidance.fftBands[0].f0 = 0.0;
         guidance.fftBands[0].f1 = lower;
 
@@ -343,13 +353,22 @@ protected:
         return (here > 10.e-3 && here > there * 1.4);
     }
 
-    double snapToTrough(double f,
-                        const int *const troughs,
-                        const double *const magnitudes) const {
+    double descendToValley(double f, const double *const magnitudes) const {
 //        return frequencyForBin(troughs[binForFrequency(f)]);
-        int bin = binForFrequency(f);
+        int b = binForFrequency(f);
+
+        for (int i = 0; i < 3; ++i) {
+            if (magnitudes[b+1] < magnitudes[b]) {
+                ++b;
+            } else if (magnitudes[b-1] < magnitudes[b]) {
+                --b;
+            } else {
+                break;
+            }
+        }
+        
+/*        
         int snapped = troughs[bin];
-        double sf = frequencyForBin(snapped);
         std::cout << "snapToTrough: " << f << " -> bin " << bin << " -> snapped " << snapped << " -> " << sf << std::endl;
         for (int i = -3; i <= 3; ++i) {
             if (i == 0) std::cout << "[";
@@ -358,6 +377,8 @@ protected:
             std::cout << " ";
         }
         std::cout << std::endl;
+*/
+        double sf = frequencyForBin(b);
         return sf;
     }
 

src/finer/R3StretcherImpl.cpp

@@ -38,7 +38,6 @@ R3StretcherImpl::R3StretcherImpl(Parameters parameters,
     m_guide(Guide::Parameters(m_parameters.sampleRate, parameters.logger)),
     m_guideConfiguration(m_guide.getConfiguration()),
     m_channelAssembly(m_parameters.channels),
-    m_troughPicker(m_guideConfiguration.classificationFftSize / 2 + 1),
     m_inhop(1),
     m_prevOuthop(1),
     m_draining(false)
@@ -677,22 +676,17 @@ R3StretcherImpl::analyseChannel(int c, int inhop, int prevInhop, int prevOuthop)
     }
 */
     
-    m_troughPicker.findNearestAndNextPeaks
-        (classifyScale->mag.data(), 3, nullptr,
-         classifyScale->troughs.data());
-            
     double instantaneousRatio = double(prevOuthop) / double(prevInhop);
     bool specialCaseUnity = true;
         
-    m_guide.calculate(instantaneousRatio,
-                      classifyScale->mag.data(),
-                      classifyScale->troughs.data(),
-                      classifyScale->prevMag.data(),
-                      cd->segmentation,
-                      cd->prevSegmentation,
-                      cd->nextSegmentation,
-                      specialCaseUnity,
-                      cd->guidance);
+    m_guide.updateGuidance(instantaneousRatio,
+                           classifyScale->mag.data(),
+                           classifyScale->prevMag.data(),
+                           cd->segmentation,
+                           cd->prevSegmentation,
+                           cd->nextSegmentation,
+                           specialCaseUnity,
+                           cd->guidance);
 }
 
 void

src/finer/R3StretcherImpl.h

@@ -109,7 +109,6 @@ protected:
         FixedVector<double> mag;
         FixedVector<double> phase;
         FixedVector<double> advancedPhase;
-        FixedVector<int> troughs;
         FixedVector<double> prevMag;
         FixedVector<double> accumulator;
 
@@ -122,7 +121,6 @@ protected:
             mag(bufSize, 0.f),
             phase(bufSize, 0.f),
             advancedPhase(bufSize, 0.f),
-            troughs(bufSize, 0),
             prevMag(bufSize, 0.f),
             accumulator(_longestFftSize, 0.f)
         { }
@@ -261,7 +259,6 @@ protected:
     Guide m_guide;
     Guide::Configuration m_guideConfiguration;
     ChannelAssembly m_channelAssembly;
-    Peak<double, std::less<double>> m_troughPicker;
     std::unique_ptr<StretchCalculator> m_calculator;
     std::unique_ptr<Resampler> m_resampler;
     std::atomic<int> m_inhop;