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diff --git a/audio/softsynth/mt32/srchelper/InternalResampler.cpp b/audio/softsynth/mt32/srchelper/InternalResampler.cpp
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+/* 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/>.
+ */
+
+#include "InternalResampler.h"
+
+#include <SincResampler.h>
+#include <ResamplerModel.h>
+
+#include "Synth.h"
+
+using namespace SRCTools;
+
+namespace MT32Emu {
+
+class SynthWrapper : public FloatSampleProvider {
+ Synth &synth;
+
+public:
+ SynthWrapper(Synth &useSynth) : synth(useSynth)
+ {}
+
+ void getOutputSamples(FloatSample *outBuffer, unsigned int size) {
+ synth.render(outBuffer, size);
+ }
+};
+
+static FloatSampleProvider &createModel(Synth &synth, SRCTools::FloatSampleProvider &synthSource, double targetSampleRate, SampleRateConverter::Quality quality) {
+ static const double MAX_AUDIBLE_FREQUENCY = 20000.0;
+
+ const double sourceSampleRate = synth.getStereoOutputSampleRate();
+ if (quality != SampleRateConverter::FASTEST) {
+ const bool oversampledMode = synth.getStereoOutputSampleRate() == Synth::getStereoOutputSampleRate(AnalogOutputMode_OVERSAMPLED);
+ // Oversampled input allows to bypass IIR interpolation stage and, in some cases, IIR decimation stage
+ if (oversampledMode && (0.5 * sourceSampleRate) <= targetSampleRate) {
+ // NOTE: In the oversampled mode, the transition band starts at 20kHz and ends at 28kHz
+ double passband = MAX_AUDIBLE_FREQUENCY;
+ double stopband = 0.5 * sourceSampleRate + MAX_AUDIBLE_FREQUENCY;
+ ResamplerStage &resamplerStage = *SincResampler::createSincResampler(sourceSampleRate, targetSampleRate, passband, stopband, ResamplerModel::DEFAULT_DB_SNR, ResamplerModel::DEFAULT_WINDOWED_SINC_MAX_UPSAMPLE_FACTOR);
+ return ResamplerModel::createResamplerModel(synthSource, resamplerStage);
+ }
+ }
+ return ResamplerModel::createResamplerModel(synthSource, sourceSampleRate, targetSampleRate, static_cast<ResamplerModel::Quality>(quality));
+}
+
+} // namespace MT32Emu
+
+using namespace MT32Emu;
+
+InternalResampler::InternalResampler(Synth &synth, double targetSampleRate, SampleRateConverter::Quality quality) :
+ synthSource(*new SynthWrapper(synth)),
+ model(createModel(synth, synthSource, targetSampleRate, quality))
+{}
+
+InternalResampler::~InternalResampler() {
+ ResamplerModel::freeResamplerModel(model, synthSource);
+ delete &synthSource;
+}
+
+void InternalResampler::getOutputSamples(float *buffer, unsigned int length) {
+ model.getOutputSamples(buffer, length);
+}