MT32: Update Munt to 2.0.3

This update uses upstream commit
777c51cdb4dbb4e02a53c23edea9086f0b600e26.

The new SampleRateConverter is added, but not built as we don't use it.
Also, building it without source changes will need additional include
directories.

This update of Munt reduces the stack size, and thus fixes bug #9630.

1 files changed, 100 insertions, 0 deletions

diff --git a/audio/softsynth/mt32/srchelper/srctools/include/IIR2xResampler.h b/audio/softsynth/mt32/srchelper/srctools/include/IIR2xResampler.h
new file mode 100644
index 0000000000..23733e4049
--- /dev/null
+++ b/audio/softsynth/mt32/srchelper/srctools/include/IIR2xResampler.h
@@ -0,0 +1,100 @@
+/* Copyright (C) 2015-2017 Sergey V. Mikayev
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU Lesser General Public License as published by
+ *  the Free Software Foundation, either version 2.1 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 Lesser General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Lesser General Public License
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef IIR_2X_RESAMPLER_H
+#define IIR_2X_RESAMPLER_H
+
+#include "ResamplerStage.h"
+
+namespace SRCTools {
+
+static const unsigned int IIR_RESAMPER_CHANNEL_COUNT = 2;
+static const unsigned int IIR_SECTION_ORDER = 2;
+
+typedef FloatSample IIRCoefficient;
+typedef FloatSample BufferedSample;
+
+typedef BufferedSample SectionBuffer[IIR_SECTION_ORDER];
+
+// Non-trivial coefficients of a 2nd-order section of a parallel bank
+// (zero-order numerator coefficient is always zero, zero-order denominator coefficient is always unity)
+struct IIRSection {
+	IIRCoefficient num1;
+	IIRCoefficient num2;
+	IIRCoefficient den1;
+	IIRCoefficient den2;
+};
+
+class IIRResampler : public ResamplerStage {
+public:
+	enum Quality {
+		// Used when providing custom IIR filter coefficients.
+		CUSTOM,
+		// Use fast elliptic filter with symmetric ripple: N=8, Ap=As=-99 dB, fp=0.125, fs = 0.25 (in terms of sample rate)
+		FAST,
+		// Use average elliptic filter with symmetric ripple: N=12, Ap=As=-106 dB, fp=0.193, fs = 0.25 (in terms of sample rate)
+		GOOD,
+		// Use sharp elliptic filter with symmetric ripple: N=18, Ap=As=-106 dB, fp=0.238, fs = 0.25 (in terms of sample rate)
+		BEST
+	};
+
+	// Returns the retained fraction of the passband for the given standard quality value
+	static double getPassbandFractionForQuality(Quality quality);
+
+protected:
+	explicit IIRResampler(const Quality quality);
+	explicit IIRResampler(const unsigned int useSectionsCount, const IIRCoefficient useFIR, const IIRSection useSections[]);
+	~IIRResampler();
+
+	const struct Constants {
+		// Coefficient of the 0-order FIR part
+		IIRCoefficient fir;
+		// 2nd-order sections that comprise a parallel bank
+		const IIRSection *sections;
+		// Number of 2nd-order sections
+		unsigned int sectionsCount;
+		// Delay line per channel per section
+		SectionBuffer *buffer;
+
+		Constants(const unsigned int useSectionsCount, const IIRCoefficient useFIR, const IIRSection useSections[], const Quality quality);
+	} constants;
+}; // class IIRResampler
+
+class IIR2xInterpolator : public IIRResampler {
+public:
+	explicit IIR2xInterpolator(const Quality quality);
+	explicit IIR2xInterpolator(const unsigned int useSectionsCount, const IIRCoefficient useFIR, const IIRSection useSections[]);
+
+	void process(const FloatSample *&inSamples, unsigned int &inLength, FloatSample *&outSamples, unsigned int &outLength);
+	unsigned int estimateInLength(const unsigned int outLength) const;
+
+private:
+	FloatSample lastInputSamples[IIR_RESAMPER_CHANNEL_COUNT];
+	unsigned int phase;
+};
+
+class IIR2xDecimator : public IIRResampler {
+public:
+	explicit IIR2xDecimator(const Quality quality);
+	explicit IIR2xDecimator(const unsigned int useSectionsCount, const IIRCoefficient useFIR, const IIRSection useSections[]);
+
+	void process(const FloatSample *&inSamples, unsigned int &inLength, FloatSample *&outSamples, unsigned int &outLength);
+	unsigned int estimateInLength(const unsigned int outLength) const;
+};
+
+} // namespace SRCTools
+
+#endif // IIR_2X_RESAMPLER_H