Lime3DS/src/audio_core/dsp_interface.cpp
2018-09-09 08:37:34 +01:00

83 lines
2.7 KiB
C++

// Copyright 2017 Citra Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
#include <cstddef>
#include "audio_core/dsp_interface.h"
#include "audio_core/sink.h"
#include "audio_core/sink_details.h"
#include "common/assert.h"
#include "core/settings.h"
namespace AudioCore {
DspInterface::DspInterface() = default;
DspInterface::~DspInterface() = default;
void DspInterface::SetSink(const std::string& sink_id, const std::string& audio_device) {
const SinkDetails& sink_details = GetSinkDetails(sink_id);
sink = sink_details.factory(audio_device);
sink->SetCallback(
[this](s16* buffer, std::size_t num_frames) { OutputCallback(buffer, num_frames); });
time_stretcher.SetOutputSampleRate(sink->GetNativeSampleRate());
}
Sink& DspInterface::GetSink() {
ASSERT(sink);
return *sink.get();
}
void DspInterface::EnableStretching(bool enable) {
if (perform_time_stretching == enable)
return;
if (!enable) {
flushing_time_stretcher = true;
}
perform_time_stretching = enable;
}
void DspInterface::OutputFrame(StereoFrame16& frame) {
if (!sink)
return;
fifo.Push(frame.data(), frame.size());
}
void DspInterface::OutputCallback(s16* buffer, std::size_t num_frames) {
std::size_t frames_written;
if (perform_time_stretching) {
const std::vector<s16> in{fifo.Pop()};
const std::size_t num_in{in.size() / 2};
frames_written = time_stretcher.Process(in.data(), num_in, buffer, num_frames);
} else if (flushing_time_stretcher) {
time_stretcher.Flush();
frames_written = time_stretcher.Process(nullptr, 0, buffer, num_frames);
frames_written += fifo.Pop(buffer, num_frames - frames_written);
flushing_time_stretcher = false;
} else {
frames_written = fifo.Pop(buffer, num_frames);
}
if (frames_written > 0) {
std::memcpy(&last_frame[0], buffer + 2 * (frames_written - 1), 2 * sizeof(s16));
}
// Hold last emitted frame; this prevents popping.
for (std::size_t i = frames_written; i < num_frames; i++) {
std::memcpy(buffer + 2 * i, &last_frame[0], 2 * sizeof(s16));
}
// Implementation of the hardware volume slider with a dynamic range of 60 dB
const float linear_volume = std::clamp(Settings::values.volume, 0.0f, 1.0f);
if (linear_volume != 1.0) {
const float volume_scale_factor = std::exp(6.90775f * linear_volume) * 0.001f;
for (std::size_t i = 0; i < num_frames; i++) {
buffer[i * 2 + 0] = static_cast<s16>(buffer[i * 2 + 0] * volume_scale_factor);
buffer[i * 2 + 1] = static_cast<s16>(buffer[i * 2 + 1] * volume_scale_factor);
}
}
}
} // namespace AudioCore