BizHawk/waterbox/ares64/ares/nall/dsp/resampler/cubic.hpp

84 lines
1.9 KiB
C++

#pragma once
#include <nall/queue.hpp>
#include <nall/serializer.hpp>
namespace nall::DSP::Resampler {
struct Cubic {
auto inputFrequency() const -> f64 { return _inputFrequency; }
auto outputFrequency() const -> f64 { return _outputFrequency; }
auto reset(f64 inputFrequency, f64 outputFrequency = 0, u32 queueSize = 0) -> void;
auto setInputFrequency(f64 inputFrequency) -> void;
auto pending() const -> bool;
auto read() -> f64;
auto write(f64 sample) -> void;
auto serialize(serializer&) -> void;
private:
f64 _inputFrequency;
f64 _outputFrequency;
f64 _ratio;
f64 _fraction;
f64 _history[4];
queue<f64> _samples;
};
inline auto Cubic::reset(f64 inputFrequency, f64 outputFrequency, u32 queueSize) -> void {
_inputFrequency = inputFrequency;
_outputFrequency = outputFrequency ? outputFrequency : _inputFrequency;
_ratio = _inputFrequency / _outputFrequency;
_fraction = 0.0;
for(auto& sample : _history) sample = 0.0;
_samples.resize(queueSize ? queueSize : _outputFrequency * 0.02); //default to 20ms max queue size
}
inline auto Cubic::setInputFrequency(f64 inputFrequency) -> void {
_inputFrequency = inputFrequency;
_ratio = _inputFrequency / _outputFrequency;
}
inline auto Cubic::pending() const -> bool {
return _samples.pending();
}
inline auto Cubic::read() -> double {
return _samples.read();
}
inline auto Cubic::write(f64 sample) -> void {
auto& mu = _fraction;
auto& s = _history;
s[0] = s[1];
s[1] = s[2];
s[2] = s[3];
s[3] = sample;
while(mu <= 1.0) {
f64 A = s[3] - s[2] - s[0] + s[1];
f64 B = s[0] - s[1] - A;
f64 C = s[2] - s[0];
f64 D = s[1];
_samples.write(A * mu * mu * mu + B * mu * mu + C * mu + D);
mu += _ratio;
}
mu -= 1.0;
}
inline auto Cubic::serialize(serializer& s) -> void {
s(_inputFrequency);
s(_outputFrequency);
s(_ratio);
s(_fraction);
s(_history);
s(_samples);
}
}