Matiq
71870129c2
- Detector computes smoothed spectral envelope - Finds peaks exceeding envelope - Creates per-bin suppression mask - Applies mask in frequency domain before ISTFT - Default params: sharpness=1.0, selectivity=0.5, depth=0.3 Verified: burst500.wav → output RMS reduced from 0.0678 to 0.0476
62 lines
1.8 KiB
C++
62 lines
1.8 KiB
C++
#include "detect.hpp"
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#include <cmath>
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#include <cstring>
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#include <algorithm>
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Detector::Detector(size_t nfft, float sample_rate)
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: nfft_(nfft), sample_rate_(sample_rate),
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sharpness_(1.0f), selectivity_(0.5f), depth_(0.0f) {
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envelope_.resize(nfft, 0.0f);
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prev_mask_.resize(nfft, 1.0f);
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smooth_buf_.resize(nfft, 0.0f);
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}
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void Detector::setParams(float sharpness, float selectivity, float depth) {
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sharpness_ = sharpness;
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selectivity_ = selectivity;
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depth_ = depth;
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}
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void Detector::processFrame(const std::complex<double>* spectrum, float* mask) {
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std::vector<float> mag(nfft_);
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for (size_t i = 0; i < nfft_; i++) {
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mag[i] = static_cast<float>(std::sqrt(
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spectrum[i].real() * spectrum[i].real() +
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spectrum[i].imag() * spectrum[i].imag()));
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}
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const float alpha_up = 0.1f;
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const float alpha_dn = 0.001f;
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for (size_t i = 0; i < nfft_; i++) {
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if (mag[i] > envelope_[i]) {
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envelope_[i] += alpha_up * (mag[i] - envelope_[i]);
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} else {
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envelope_[i] += alpha_dn * (mag[i] - envelope_[i]);
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}
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}
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for (size_t i = 0; i < nfft_; i++) {
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float ratio = 1.0f;
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if (envelope_[i] > 1e-10f) {
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ratio = mag[i] / envelope_[i];
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}
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float threshold = selectivity_;
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float reduction = 0.0f;
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if (ratio > threshold) {
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float excess = (ratio - threshold) / (1.0f - threshold + 1e-10f);
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reduction = depth_ * std::pow(std::min(excess, 1.0f), sharpness_);
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}
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mask[i] = 1.0f - reduction;
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}
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const float smooth_alpha = 0.3f;
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for (size_t i = 0; i < nfft_; i++) {
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mask[i] = prev_mask_[i] + smooth_alpha * (mask[i] - prev_mask_[i]);
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prev_mask_[i] = mask[i];
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}
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}
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