frequency_shifter.hpp

Go to the documentation of this file.

#pragma once

 
#include <pulp/signal/frequency_shifter_ssb.hpp>
 
#include <cmath>
 
namespace pulp::signal {

template <typename SampleType = double>
using HilbertPairT = HilbertQuadratureNetworkT<SampleType>;

template <typename SampleType = float>
class FrequencyShifterT {
public:
    void set_sample_rate(double sr) {
        sample_rate_ = sr > 0.0 ? sr : sample_rate_;
        update();
    }

    void set_shift_hz(double hz) {
        shift_hz_ = hz;
        update();
    }
 
    double shift_hz() const { return shift_hz_; }
 
    void reset() {
        hilbert_.reset();
        phase_ = 0.0;
    }
 
    SampleType process(SampleType input) {
        const auto pair = hilbert_.process(static_cast<double>(input));
 
        phase_ += increment_;
        phase_ -= std::floor(phase_);
 
        const double angle = 2.0 * 3.14159265358979323846 * phase_;
        return static_cast<SampleType>(pair.in_phase * std::cos(angle) -
                                       pair.quadrature * std::sin(angle));
    }
 
private:
    void update() { increment_ = shift_hz_ / sample_rate_; }
 
    HilbertPairT<double> hilbert_;
    double sample_rate_ = 44100.0;
    double shift_hz_ = 0.0;
    double increment_ = 0.0;
    double phase_ = 0.0;
};
 
using HilbertPair = HilbertPairT<double>;
using FrequencyShifter = FrequencyShifterT<float>;
using FrequencyShifter64 = FrequencyShifterT<double>;
 
}  // namespace pulp::signal