New Spectrum Analyzer (LMMS#4950)

Replace old spectrum analyzer by new one with higher resolution and
many new features.

Resolves LMMS#2847.

include/EffectControlDialog.h

@@ -40,6 +40,8 @@ class LMMS_EXPORT EffectControlDialog : public QWidget, public ModelView
 	EffectControlDialog( EffectControls * _controls );
 	virtual ~EffectControlDialog();
 
+	virtual bool isResizable() const {return false;}
+
 
 signals:
 	void closed();

include/SubWindow.h

@@ -30,7 +30,6 @@
 #include <QGraphicsDropShadowEffect>
 #include <QMdiSubWindow>
 #include <QLabel>
-#include <QPainter>
 #include <QPushButton>
 #include <QString>
 

include/fft_helpers.h

@@ -2,6 +2,7 @@
  * fft_helpers.h - some functions around FFT analysis
  *
  * Copyright (c) 2008-2012 Tobias Doerffel <tobydox/at/users.sourceforge.net>
+ * Copyright (c) 2019 Martin Pavelek <he29.HS/at/gmail.com>
  *
  * This file is part of LMMS - https://lmms.io
  *
@@ -28,57 +29,90 @@
 
 #include "lmms_export.h"
 
+#include <vector>
 #include <fftw3.h>
 
-const int FFT_BUFFER_SIZE = 2048;
+// NOTE: FFT_BUFFER_SIZE should be considered deprecated!
+// It is used by Eq plugin and some older code here, but this should be a user
+// switchable parameter, not a constant. Use a value from FFT_BLOCK_SIZES
+const unsigned int FFT_BUFFER_SIZE = 2048;
 
-enum WINDOWS
+// Allowed FFT block sizes. Ranging from barely useful to barely acceptable
+// because of performance and latency reasons.
+const std::vector<unsigned int> FFT_BLOCK_SIZES = {256, 512, 1024, 2048, 4096, 8192, 16384};
+
+// List of FFT window functions supported by precomputeWindow()
+enum FFT_WINDOWS
 {
-        KAISER=1,
-        RECTANGLE,
-        HANNING,
-        HAMMING
+	RECTANGULAR = 0,
+	BLACKMAN_HARRIS,
+	HAMMING,
+	HANNING
 };
 
-/* returns biggest value from abs_spectrum[spec_size] array
+
+/**	Returns biggest value from abs_spectrum[spec_size] array.
+ *
+ *	@return -1 on error, 0 on success
+ */
+float LMMS_EXPORT maximum(const float *abs_spectrum, unsigned int spec_size);
+float LMMS_EXPORT maximum(const std::vector<float> &abs_spectrum);
+
+
+/** Normalize the abs_spectrum array of absolute values to a 0..1 range
+ *	based on supplied energy and stores it in the norm_spectrum array.
+ *
+ *	@return -1 on error
+ */
+int LMMS_EXPORT normalize(const float *abs_spectrum, float *norm_spectrum, unsigned int bin_count, unsigned int block_size);
+int LMMS_EXPORT normalize(const std::vector<float> &abs_spectrum, std::vector<float> &norm_spectrum, unsigned int block_size);
+
+
+/**	Check if the spectrum contains any non-zero value.
  *
- *    returns -1 on error
+ *	@return 1 if spectrum contains any non-zero value
+ *	@return 0 otherwise
  */
-float LMMS_EXPORT maximum( float * _abs_spectrum, unsigned int _spec_size );
+int LMMS_EXPORT notEmpty(const std::vector<float> &spectrum);
+
 
-/* apply hanning or hamming window to channel
+/**	Precompute a window function for later real-time use.
+ *	Set normalized to false if you do not want to apply amplitude correction.
  *
- *    returns -1 on error
+ *	@return -1 on error
  */
-int LMMS_EXPORT hanming( float * _timebuffer, int _length, WINDOWS _type );
+int LMMS_EXPORT precomputeWindow(float *window, unsigned int length, FFT_WINDOWS type, bool normalized = true);
 
-/* compute absolute values of complex_buffer, save to absspec_buffer
- * take care that - compl_len is not bigger than complex_buffer!
- *                - absspec buffer is big enough!
+
+/**	Compute absolute values of complex_buffer, save to absspec_buffer.
+ *	Take care that - compl_len is not bigger than complex_buffer!
+ *				   - absspec buffer is big enough!
  *
- *    returns 0 on success, else -1
+ *	@return 0 on success, else -1
  */
-int LMMS_EXPORT absspec( fftwf_complex * _complex_buffer, float * _absspec_buffer,
-							int _compl_length );
+int LMMS_EXPORT absspec(const fftwf_complex *complex_buffer, float *absspec_buffer,
+						unsigned int compl_length);
+
 
-/* build fewer subbands from many absolute spectrum values
- * take care that - compressedbands[] array num_new elements long
- *                - num_old > num_new
+/**	Build fewer subbands from many absolute spectrum values.
+ *	Take care that - compressedbands[] array num_new elements long
+ *				   - num_old > num_new
  *
- *    returns 0 on success, else -1
+ *	@return 0 on success, else -1
  */
-int LMMS_EXPORT compressbands( float * _absspec_buffer, float * _compressedband,
-			int _num_old, int _num_new, int _bottom, int _top );
+int LMMS_EXPORT compressbands(const float * _absspec_buffer, float * _compressedband,
+			int _num_old, int _num_new, int _bottom, int _top);
+
 
+int LMMS_EXPORT calc13octaveband31(float * _absspec_buffer, float * _subbands,
+				int _num_spec, float _max_frequency);
 
-int LMMS_EXPORT calc13octaveband31( float * _absspec_buffer, float * _subbands,
-				int _num_spec, float _max_frequency );
 
-/* compute power of finite time sequence
- * take care num_values is length of timesignal[]
+/**	Compute power of finite time sequence.
+ *	Take care num_values is length of timesignal[].
  *
- *    returns power on success, else -1
+ *	@return power on success, else -1
  */
-float LMMS_EXPORT signalpower(float *timesignal, int num_values);
+float LMMS_EXPORT signalpower(const float *timesignal, int num_values);
 
 #endif

plugins/SpectrumAnalyzer/Analyzer.cpp

@@ -0,0 +1,75 @@
+/*
+ * Analyzer.cpp - definition of Analyzer class.
+ *
+ * Copyright (c) 2019 Martin Pavelek <he29/dot/HS/at/gmail/dot/com>
+ *
+ * Based partially on Eq plugin code,
+ * Copyright (c) 2014-2017, David French <dave/dot/french3/at/googlemail/dot/com>
+ *
+ * This file is part of LMMS - https://lmms.io
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program (see COPYING); if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301 USA.
+ *
+ */
+
+#include "Analyzer.h"
+
+#include "embed.h"
+#include "plugin_export.h"
+
+
+extern "C" {
+	Plugin::Descriptor PLUGIN_EXPORT analyzer_plugin_descriptor =
+	{
+		"spectrumanalyzer",
+		"Spectrum Analyzer",
+		QT_TRANSLATE_NOOP("pluginBrowser", "A graphical spectrum analyzer."),
+		"Martin Pavelek <he29/dot/HS/at/gmail/dot/com>",
+		0x0100,
+		Plugin::Effect,
+		new PluginPixmapLoader("logo"),
+		NULL,
+		NULL
+	};
+}
+
+
+Analyzer::Analyzer(Model *parent, const Plugin::Descriptor::SubPluginFeatures::Key *key) :
+	Effect(&analyzer_plugin_descriptor, parent, key),
+	m_processor(&m_controls),
+	m_controls(this)
+{
+}
+
+
+// Take audio data and pass them to the spectrum processor.
+// Skip processing if the controls dialog isn't visible, it would only waste CPU cycles.
+bool Analyzer::processAudioBuffer(sampleFrame *buffer, const fpp_t frame_count)
+{
+	if (!isEnabled() || !isRunning ()) {return false;}
+	if (m_controls.isViewVisible()) {m_processor.analyse(buffer, frame_count);}
+	return isRunning();
+}
+
+
+extern "C" {
+	// needed for getting plugin out of shared lib
+	PLUGIN_EXPORT Plugin *lmms_plugin_main(Model *parent, void *data)
+	{
+		return new Analyzer(parent, static_cast<const Plugin::Descriptor::SubPluginFeatures::Key *>(data));
+	}
+}
+

plugins/SpectrumAnalyzer/SpectrumAnalyzerControlDialog.h → plugins/SpectrumAnalyzer/Analyzer.h

@@ -1,7 +1,9 @@
-/*
- * SpectrumAnalyzerControlDialog.h - view for spectrum analyzer
+/* Analyzer.h - declaration of Analyzer class.
  *
- * Copyright (c) 2008-2014 Tobias Doerffel <tobydox/at/users.sourceforge.net>
+ * Copyright (c) 2019 Martin Pavelek <he29/dot/HS/at/gmail/dot/com>
+ *
+ * Based partially on Eq plugin code,
+ * Copyright (c) 2014-2017, David French <dave/dot/french3/at/googlemail/dot/com>
  *
  * This file is part of LMMS - https://lmms.io
  *
@@ -22,32 +24,30 @@
  *
  */
 
-#ifndef _SPECTRUM_ANALYZER_CONTROL_DIALOG_H
-#define _SPECTRUM_ANALYZER_CONTROL_DIALOG_H
-
-#include "EffectControlDialog.h"
-
+#ifndef ANALYZER_H
+#define ANALYZER_H
 
-class SpectrumAnalyzerControls;
+#include "Effect.h"
+#include "SaControls.h"
+#include "SaProcessor.h"
 
 
-class SpectrumAnalyzerControlDialog : public EffectControlDialog
+//! Top level class; handles LMMS interface and feeds data to the data processor.
+class Analyzer : public Effect
 {
-	Q_OBJECT
 public:
-	SpectrumAnalyzerControlDialog( SpectrumAnalyzerControls* controls );
-	virtual ~SpectrumAnalyzerControlDialog()
-	{
-	}
+	Analyzer(Model *parent, const Descriptor::SubPluginFeatures::Key *key);
+	virtual ~Analyzer() {};
 
-private:
-	virtual void paintEvent( QPaintEvent* event );
+	bool processAudioBuffer(sampleFrame *buffer, const fpp_t frame_count) override;
+	EffectControls *controls() override {return &m_controls;}
 
-	SpectrumAnalyzerControls* m_controls;
+	SaProcessor *getProcessor() {return &m_processor;}
 
-	QPixmap m_logXAxis;
-	QPixmap m_logYAxis;
+private:
+	SaProcessor m_processor;
+	SaControls m_controls;
+};
 
-} ;
+#endif // ANALYZER_H
 
-#endif

plugins/SpectrumAnalyzer/CMakeLists.txt

@@ -1,4 +1,5 @@
 INCLUDE(BuildPlugin)
 INCLUDE_DIRECTORIES(${FFTW3F_INCLUDE_DIRS})
 LINK_LIBRARIES(${FFTW3F_LIBRARIES})
-BUILD_PLUGIN(spectrumanalyzer SpectrumAnalyzer.cpp SpectrumAnalyzerControls.cpp SpectrumAnalyzerControlDialog.cpp SpectrumAnalyzer.h SpectrumAnalyzerControls.h SpectrumAnalyzerControlDialog.h MOCFILES SpectrumAnalyzerControlDialog.h SpectrumAnalyzerControls.h EMBEDDED_RESOURCES *.png)
+BUILD_PLUGIN(analyzer Analyzer.cpp SaProcessor.cpp SaControls.cpp SaControlsDialog.cpp SaSpectrumView.cpp SaWaterfallView.cpp
+MOCFILES SaProcessor.h SaControls.h SaControlsDialog.h SaSpectrumView.h SaWaterfallView.h EMBEDDED_RESOURCES *.svg logo.png)

plugins/SpectrumAnalyzer/README.md

@@ -0,0 +1,19 @@
+# Spectrum Analyzer plugin
+
+## Overview
+
+This plugin consists of three widgets and back-end code to provide them with required data.
+
+The top-level widget is SaControlDialog. It populates a configuration widget (created dynamically) and instantiates spectrum display widgets. Its main back-end class is SaControls, which holds all configuration values and globally valid constants (e.g. range definitions).
+
+SaSpectrumDisplay and SaWaterfallDisplay show the result of spectrum analysis. Their main back-end class is SaProcessor, which performs FFT analysis on data received from the Analyzer class, which in turn handles the interface with LMMS.
+
+
+## Changelog
+
+	1.0.1	2019-06-02
+		- code style changes
+		- added tool-tips
+		- use const for unmodified arrays passed to fft_helpers
+	1.0.0	2019-04-07
+		- initial release