Tuner: filter result with time

qml/TunerScreen.qml

@@ -25,7 +25,7 @@ Item {
 		width: Math.min(parent.width, parent.height * 1.5)
 		height: width / 2
 
-		level: tuner.deviation * 100
+		level: tuner.found ? tuner.deviation * 100 : -50
 	}
 
 	ScaleToise {

src/Tuner.cpp

@@ -34,6 +34,8 @@ Tuner::Tuner()
 	running = false;
 	freq = deviation = 0;
 	note = octave = 0; 
+	found = false;
+	count_found = count_not_found = 0;
 
 	high_filter = new LinearFilter<int16_t>(3, a10, b10);
 
@@ -70,6 +72,7 @@ Tuner::~Tuner()
 void Tuner::Start()
 {
 	cerr << __func__ << endl;
+	count_found = count_not_found = 0;
 	nb_sample_running = 0;
 	blank_prevent(true);
 	high_filter->Clear();
@@ -101,6 +104,45 @@ void Tuner::AudioCb(const QAudioBuffer &buffer)
 	AudioAnalyse(ptr, nbFrame);
 }
 
+void Tuner::SetFound(int n, int o, double d)
+{
+	if (n != note_found) {
+		note_found = n;
+		count_found = 0;
+		SetNotFound();
+	}
+	else if (count_found++ >= nbConfirm) {
+		count_not_found = 0;
+		if (!found) {
+			found = true;
+			foundChanged();
+		}
+		if (note != n) {
+			note = n;
+			noteChanged();
+		}
+		if (octave != o) {
+			octave = o;
+			octaveChanged();
+		}
+		if (deviation != d) {
+			deviation = d;
+			deviationChanged();
+		}
+	}
+}
+
+void Tuner::SetNotFound()
+{
+	if (count_not_found++ >= nbDefect) {
+		count_found = 0;
+		if (found) {
+			found = false;
+			foundChanged();
+		}
+	}
+}
+
 void Tuner::AudioAnalyse(const int16_t *ptr, int nb_frame)
 {
 	nb_sample_running += nb_frame;
@@ -112,12 +154,13 @@ void Tuner::AudioAnalyse(const int16_t *ptr, int nb_frame)
 		freqChanged();
 
 		if (freq) {
-			note = scale->FindNote(freq, octave, deviation);
-			noteChanged();
-			noteNameChanged();
-			octaveChanged();
-			deviationChanged();
-			//std::cerr << note << " " << scale->NoteName(note) << std::endl;
+			int n, o;
+			double d;
+			n = scale->FindNote(freq, o, d);
+			SetFound(n, o, d);
+		}
+		else { // no freq
+			SetNotFound();
 		}
 	}
 
@@ -164,3 +207,8 @@ const char* Tuner::GetNoteName()
 {
 	return scale->NoteName(note);
 }
+
+bool Tuner::GetFound()
+{
+	return found;
+}

src/Tuner.hpp

@@ -12,6 +12,7 @@ class Tuner : public QObject {
 	Q_PROPERTY(double deviation READ GetDeviation NOTIFY deviationChanged)
 	Q_PROPERTY(int note READ GetNote NOTIFY noteChanged)
 	Q_PROPERTY(int octave READ GetOctave NOTIFY octaveChanged)
+	Q_PROPERTY(bool found READ GetFound NOTIFY foundChanged)
 	Q_PROPERTY(QString noteName READ GetNoteName NOTIFY noteNameChanged)
 
 	private:
@@ -23,17 +24,25 @@ class Tuner : public QObject {
 	ZeroCross<int16_t> *cross;
 	Scale *scale;
 
-	bool running;
+	bool running, found;
 	double freq, deviation;
 	int note, octave, nb_sample_running;
+	int note_found, count_found, count_not_found;
 
 	static const int rate = 16000;
 	static const int defaultNbFrame = 1024;
 	static const int defaultFreqMin = 50;
 	static const int defaultFreqMax = 2000;
 	static const int nbSamplePreventRunning = rate * 40; // 40 seconds
+	/// number of analyses to confirm a note
+	static const int nbConfirm = 3;
+	/// number of analyses to drop a note
+	static const int nbDefect = 20;
+
 
 	inline void ComputeFrame(int16_t v);
+	void SetFound(int note, int octave, double deviation);
+	void SetNotFound();
 
 	private slots:
 	void AudioCb(const QAudioBuffer &buffer);
@@ -53,6 +62,7 @@ class Tuner : public QObject {
 	int GetNote();
 	int GetOctave();
 	double GetDeviation();
+	bool GetFound();
 	const char* GetNoteName();
 
 	signals:
@@ -62,4 +72,5 @@ class Tuner : public QObject {
 	void noteNameChanged();
 	void octaveChanged();
 	void deviationChanged();
+	void foundChanged();
 };