diff options
Diffstat (limited to 'audio/softsynth/mt32/srchelper/SamplerateAdapter.cpp')
-rw-r--r-- | audio/softsynth/mt32/srchelper/SamplerateAdapter.cpp | 99 |
1 files changed, 99 insertions, 0 deletions
diff --git a/audio/softsynth/mt32/srchelper/SamplerateAdapter.cpp b/audio/softsynth/mt32/srchelper/SamplerateAdapter.cpp new file mode 100644 index 0000000000..33fcfa81dd --- /dev/null +++ b/audio/softsynth/mt32/srchelper/SamplerateAdapter.cpp @@ -0,0 +1,99 @@ +/* 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 "SamplerateAdapter.h" + +#include "Synth.h" + +using namespace MT32Emu; + +static const unsigned int CHANNEL_COUNT = 2; + +long SamplerateAdapter::getInputSamples(void *cb_data, float **data) { + SamplerateAdapter *instance = static_cast<SamplerateAdapter *>(cb_data); + unsigned int length = instance->inBufferSize < 1 ? 1 : (MAX_SAMPLES_PER_RUN < instance->inBufferSize ? MAX_SAMPLES_PER_RUN : instance->inBufferSize); + instance->synth.render(instance->inBuffer, length); + *data = instance->inBuffer; + instance->inBufferSize -= length; + return length; +} + +SamplerateAdapter::SamplerateAdapter(Synth &useSynth, double targetSampleRate, SampleRateConverter::Quality quality) : + synth(useSynth), + inBuffer(new float[CHANNEL_COUNT * MAX_SAMPLES_PER_RUN]), + inBufferSize(MAX_SAMPLES_PER_RUN), + inputToOutputRatio(useSynth.getStereoOutputSampleRate() / targetSampleRate), + outputToInputRatio(targetSampleRate / useSynth.getStereoOutputSampleRate()) +{ + int error; + int conversionType; + switch (quality) { + case SampleRateConverter::FASTEST: + conversionType = SRC_LINEAR; + break; + case SampleRateConverter::FAST: + conversionType = SRC_SINC_FASTEST; + break; + case SampleRateConverter::BEST: + conversionType = SRC_SINC_BEST_QUALITY; + break; + case SampleRateConverter::GOOD: + default: + conversionType = SRC_SINC_MEDIUM_QUALITY; + break; + }; + resampler = src_callback_new(getInputSamples, conversionType, CHANNEL_COUNT, &error, this); + if (error != 0) { + synth.printDebug("SamplerateAdapter: Creation of Samplerate instance failed: %s\n", src_strerror(error)); + src_delete(resampler); + resampler = NULL; + } +} + +SamplerateAdapter::~SamplerateAdapter() { + delete[] inBuffer; + src_delete(resampler); +} + +void SamplerateAdapter::getOutputSamples(float *buffer, unsigned int length) { + if (resampler == NULL) { + Synth::muteSampleBuffer(buffer, CHANNEL_COUNT * length); + return; + } + while (length > 0) { + inBufferSize = static_cast<unsigned int>(length * inputToOutputRatio + 0.5); + long gotFrames = src_callback_read(resampler, outputToInputRatio, long(length), buffer); + int error = src_error(resampler); + if (error != 0) { + synth.printDebug("SamplerateAdapter: Samplerate error during processing: %s > resetting\n", src_strerror(error)); + error = src_reset(resampler); + if (error != 0) { + synth.printDebug("SamplerateAdapter: Samplerate failed to reset: %s\n", src_strerror(error)); + src_delete(resampler); + resampler = NULL; + Synth::muteSampleBuffer(buffer, CHANNEL_COUNT * length); + synth.printDebug("SamplerateAdapter: Samplerate disabled\n"); + return; + } + continue; + } + if (gotFrames <= 0) { + synth.printDebug("SamplerateAdapter: got %li frames from Samplerate, weird\n", gotFrames); + } + buffer += CHANNEL_COUNT * gotFrames; + length -= gotFrames; + } +} |