1 files changed, 106 insertions, 0 deletions
diff --git a/audio/softsynth/mt32/srchelper/SoxrAdapter.cpp b/audio/softsynth/mt32/srchelper/SoxrAdapter.cpp
new file mode 100644
index 0000000000..b13192be92
--- /dev/null
+++ b/audio/softsynth/mt32/srchelper/SoxrAdapter.cpp
@@ -0,0 +1,106 @@
+/* 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 "SoxrAdapter.h"
+
+#include "Synth.h"
+
+using namespace MT32Emu;
+
+static const unsigned int CHANNEL_COUNT = 2;
+
+size_t SoxrAdapter::getInputSamples(void *input_fn_state, soxr_in_t *data, size_t requested_len) {
+	unsigned int length = requested_len < 1 ? 1 : (MAX_SAMPLES_PER_RUN < requested_len ? MAX_SAMPLES_PER_RUN : requested_len);
+	SoxrAdapter *instance = static_cast<SoxrAdapter *>(input_fn_state);
+	instance->synth.render(instance->inBuffer, length);
+	*data = instance->inBuffer;
+	return length;
+}
+
+SoxrAdapter::SoxrAdapter(Synth &useSynth, double targetSampleRate, SampleRateConverter::Quality quality) :
+	synth(useSynth),
+	inBuffer(new float[CHANNEL_COUNT * MAX_SAMPLES_PER_RUN])
+{
+	soxr_io_spec_t ioSpec = soxr_io_spec(SOXR_FLOAT32_I, SOXR_FLOAT32_I);
+	unsigned long qualityRecipe;
+	switch (quality) {
+	case SampleRateConverter::FASTEST:
+		qualityRecipe = SOXR_QQ;
+		break;
+	case SampleRateConverter::FAST:
+		qualityRecipe = SOXR_LQ;
+		break;
+	case SampleRateConverter::GOOD:
+		qualityRecipe = SOXR_MQ;
+		break;
+	case SampleRateConverter::BEST:
+	default:
+		qualityRecipe = SOXR_16_BITQ;
+		break;
+	};
+	soxr_quality_spec_t qSpec = soxr_quality_spec(qualityRecipe, 0);
+	soxr_runtime_spec_t rtSpec = soxr_runtime_spec(1);
+	soxr_error_t error;
+	resampler = soxr_create(synth.getStereoOutputSampleRate(), targetSampleRate, CHANNEL_COUNT, &error, &ioSpec, &qSpec, &rtSpec);
+	if (error != NULL) {
+		synth.printDebug("SoxrAdapter: Creation of SOXR instance failed: %s\n", soxr_strerror(error));
+		soxr_delete(resampler);
+		resampler = NULL;
+		return;
+	}
+	error = soxr_set_input_fn(resampler, getInputSamples, this, MAX_SAMPLES_PER_RUN);
+	if (error != NULL) {
+		synth.printDebug("SoxrAdapter: Installing sample feed for SOXR failed: %s\n", soxr_strerror(error));
+		soxr_delete(resampler);
+		resampler = NULL;
+	}
+}
+
+SoxrAdapter::~SoxrAdapter() {
+	delete[] inBuffer;
+	if (resampler != NULL) {
+		soxr_delete(resampler);
+	}
+}
+
+void SoxrAdapter::getOutputSamples(float *buffer, unsigned int length) {
+	if (resampler == NULL) {
+		Synth::muteSampleBuffer(buffer, CHANNEL_COUNT * length);
+		return;
+	}
+	while (length > 0) {
+		size_t gotFrames = soxr_output(resampler, buffer, size_t(length));
+		soxr_error_t error = soxr_error(resampler);
+		if (error != NULL) {
+			synth.printDebug("SoxrAdapter: SOXR error during processing: %s > resetting\n", soxr_strerror(error));
+			error = soxr_clear(resampler);
+			if (error != NULL) {
+				synth.printDebug("SoxrAdapter: SOXR failed to reset: %s\n", soxr_strerror(error));
+				soxr_delete(resampler);
+				resampler = NULL;
+				Synth::muteSampleBuffer(buffer, CHANNEL_COUNT * length);
+				synth.printDebug("SoxrAdapter: SOXR disabled\n");
+				return;
+			}
+			continue;
+		}
+		if (gotFrames == 0) {
+			synth.printDebug("SoxrAdapter: got 0 frames from SOXR, weird\n");
+		}
+		buffer += CHANNEL_COUNT * gotFrames;
+		length -= static_cast<unsigned int>(gotFrames);
+	}
+}