bandpass.hpp

#pragma once
#include "synapse-app-sdk/dsp/filter/base_filter.hpp"
#include <iostream>
#include <memory>
 
namespace synapse {

template <int FilterOrder>
std::unique_ptr<synapse::BaseFilter> create_bandpass_filter(const float sample_rate_hz,
                                                            const float low_cutoff_hz,
                                                            const float high_cutoff_hz) {
  // TODO: Validate input
  const double bandwidth = high_cutoff_hz - low_cutoff_hz;
  const double center_frequency = high_cutoff_hz - (bandwidth / 2);
  if (bandwidth <= 0) {
    return nullptr;
  }
  Iir::Butterworth::BandPass<FilterOrder> filter;
  try {
    filter.setup(sample_rate_hz, center_frequency, bandwidth);
    return std::make_unique<FilterWrapper<decltype(filter)>>(std::move(filter));
  } catch (const std::exception& e) {
    std::cerr << "Error setting up filter with" << "sample_rate: " << sample_rate_hz
              << "center: " << center_frequency << "bandwidth: " << bandwidth << "why: " << e.what()
              << std::endl;
    return nullptr;
  }
}
 
}  // namespace synapse