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Fixes to filtering

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Ryzerth
2021-04-17 03:38:48 +02:00
parent 3bf4f0ce01
commit d1e553f05a
7 changed files with 45 additions and 39 deletions
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37
core/src/dsp/window.h
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@@ -51,38 +51,21 @@ namespace dsp {
}
void createTaps(float* taps, int tapCount, float factor = 1.0f) {
// // Calculate cuttoff frequency
// float omega = 2.0f * FL_M_PI * (_cutoff / _sampleRate);
// if (omega > FL_M_PI) { omega = FL_M_PI; }
// Calculate cuttoff frequency
float omega = 2.0f * FL_M_PI * (_cutoff / _sampleRate);
if (omega > FL_M_PI) { omega = FL_M_PI; }
// // Generate taps
// float val;
// float sum = 0.0f;
// for (int i = 0; i < tapCount; i++) {
// val = math::sinc(omega, i-(tapCount/2), FL_M_PI) * window_function::blackman(i, tapCount - 1);
// taps[i] = val;
// sum += val;
// }
// // Normalize taps and multiply by supplied factor
// for (int i = 0; i < tapCount; i++) {
// taps[i] *= factor;
// taps[i] /= sum;
// }
float fc = _cutoff / _sampleRate;
if (fc > 1.0f) {
fc = 1.0f;
}
float tc = tapCount;
float sum = 0.0f;
// Generate taps
float val;
float sum = 0.0f;
float tc = tapCount;
for (int i = 0; i < tapCount; i++) {
val = (sin(2.0f * FL_M_PI * fc * ((float)i - (tc / 2))) / ((float)i - (tc / 2))) *
(0.42f - (0.5f * cos(2.0f * FL_M_PI / tc)) + (0.8f * cos(4.0f * FL_M_PI / tc)));
taps[i] = val; // tapCount - i - 1
val = math::sinc(omega, (float)i - (tc/2), FL_M_PI) * window_function::blackman(i, tc - 1);
taps[i] = val;
sum += val;
}
// Normalize taps and multiply by supplied factor
for (int i = 0; i < tapCount; i++) {
taps[i] *= factor;
taps[i] /= sum;