1 files changed, 97 insertions, 0 deletions
diff --git a/audio/softsynth/mt32/SampleRateConverter.cpp b/audio/softsynth/mt32/SampleRateConverter.cpp
new file mode 100644
index 0000000000..70f860f395
--- /dev/null
+++ b/audio/softsynth/mt32/SampleRateConverter.cpp
@@ -0,0 +1,97 @@
+/* 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 "SampleRateConverter.h"
+
+#if MT32EMU_WITH_LIBSOXR_RESAMPLER
+#include "srchelper/SoxrAdapter.h"
+#elif MT32EMU_WITH_LIBSAMPLERATE_RESAMPLER
+#include "srchelper/SamplerateAdapter.h"
+#else
+#include "srchelper/InternalResampler.h"
+#endif
+
+#include "Synth.h"
+
+using namespace MT32Emu;
+
+static inline void *createDelegate(Synth &synth, double targetSampleRate, SampleRateConverter::Quality quality) {
+#if MT32EMU_WITH_LIBSOXR_RESAMPLER
+	return new SoxrAdapter(synth, targetSampleRate, quality);
+#elif MT32EMU_WITH_LIBSAMPLERATE_RESAMPLER
+	return new SamplerateAdapter(synth, targetSampleRate, quality);
+#else
+	return new InternalResampler(synth, targetSampleRate, quality);
+#endif
+}
+
+AnalogOutputMode SampleRateConverter::getBestAnalogOutputMode(double targetSampleRate) {
+	if (Synth::getStereoOutputSampleRate(AnalogOutputMode_ACCURATE) < targetSampleRate) {
+		return AnalogOutputMode_OVERSAMPLED;
+	} else if (Synth::getStereoOutputSampleRate(AnalogOutputMode_COARSE) < targetSampleRate) {
+		return AnalogOutputMode_ACCURATE;
+	}
+	return AnalogOutputMode_COARSE;
+}
+
+SampleRateConverter::SampleRateConverter(Synth &useSynth, double targetSampleRate, Quality useQuality) :
+	synthInternalToTargetSampleRateRatio(SAMPLE_RATE / targetSampleRate),
+	srcDelegate(createDelegate(useSynth, targetSampleRate, useQuality))
+{}
+
+SampleRateConverter::~SampleRateConverter() {
+#if MT32EMU_WITH_LIBSOXR_RESAMPLER
+	delete static_cast<SoxrAdapter *>(srcDelegate);
+#elif MT32EMU_WITH_LIBSAMPLERATE_RESAMPLER
+	delete static_cast<SamplerateAdapter *>(srcDelegate);
+#else
+	delete static_cast<InternalResampler *>(srcDelegate);
+#endif
+}
+
+void SampleRateConverter::getOutputSamples(float *buffer, unsigned int length) {
+#if MT32EMU_WITH_LIBSOXR_RESAMPLER
+	static_cast<SoxrAdapter *>(srcDelegate)->getOutputSamples(buffer, length);
+#elif MT32EMU_WITH_LIBSAMPLERATE_RESAMPLER
+	static_cast<SamplerateAdapter *>(srcDelegate)->getOutputSamples(buffer, length);
+#else
+	static_cast<InternalResampler *>(srcDelegate)->getOutputSamples(buffer, length);
+#endif
+}
+
+void SampleRateConverter::getOutputSamples(Bit16s *outBuffer, unsigned int length) {
+	static const unsigned int CHANNEL_COUNT = 2;
+
+	float floatBuffer[CHANNEL_COUNT * MAX_SAMPLES_PER_RUN];
+	while (length > 0) {
+		const unsigned int size = MAX_SAMPLES_PER_RUN < length ? MAX_SAMPLES_PER_RUN : length;
+		getOutputSamples(floatBuffer, size);
+		float *outs = floatBuffer;
+		float *ends = floatBuffer + CHANNEL_COUNT * size;
+		while (outs < ends) {
+			*(outBuffer++) = Synth::convertSample(*(outs++));
+		}
+		length -= size;
+	}
+}
+
+double SampleRateConverter::convertOutputToSynthTimestamp(double outputTimestamp) const {
+	return outputTimestamp * synthInternalToTargetSampleRateRatio;
+}
+
+double SampleRateConverter::convertSynthToOutputTimestamp(double synthTimestamp) const {
+	return synthTimestamp / synthInternalToTargetSampleRateRatio;
+}