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light changes

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This commit is contained in:
KubaPro010
2025-01-23 10:03:39 +01:00
parent 43521d90a8
commit 7096a6e572
13 changed files with 106 additions and 300 deletions
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14
lib/filters.c
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@@ -1,6 +1,11 @@
#include "filters.h"
void init_rc(ResistorCapacitor *rc, float tau, float sample_rate) {
void init_rc(ResistorCapacitor *rc, float alpha) {
rc->prev_sample = 0.0f;
rc->alpha = alpha;
}
void init_rc_tau(ResistorCapacitor *rc, float tau, float sample_rate) {
rc->prev_sample = 0.0f;
rc->alpha = exp(-1 / (tau * sample_rate));
}
@@ -8,15 +13,16 @@ void init_rc(ResistorCapacitor *rc, float tau, float sample_rate) {
float apply_pre_emphasis(ResistorCapacitor *rc, float sample) {
float audio = sample-rc->alpha*rc->prev_sample;
rc->prev_sample = audio;
return audio*2;
return audio;
}
void init_low_pass_filter(ResistorCapacitor *rc, float cutoff_frequency, float sample_rate) {
init_rc(&rc, (-1 / (sample_rate * log(sample_rate/(sample_rate+(1/(M_2PI*cutoff_frequency)))))), sample_rate);
float RC = 1.0f / (M_2PI * cutoff_frequency);
init_rc(&rc, 1.0f / (1.0f + sample_rate * RC));
}
float apply_low_pass_filter(ResistorCapacitor *rc, float sample) {
float output = rc->alpha*sample+(1-rc->alpha)*rc->prev_sample;
float output = rc->alpha*sample+(1.0f-rc->alpha)*rc->prev_sample;
rc->prev_sample = output;
return output;
}

7
lib/filters.h
View File

@@ -5,21 +5,18 @@
#include <stdlib.h>
#include "constants.h"
#define FIR_PHASES 32
#define FIR_TAPS 32
typedef struct {
float alpha;
float prev_sample;
} ResistorCapacitor;
void init_rc(ResistorCapacitor *pe, float tau, float sample_rate);
void init_rc(ResistorCapacitor *pe, float alpha);
void init_rc_tau(ResistorCapacitor *pe, float tau, float sample_rate);
float apply_pre_emphasis(ResistorCapacitor *pe, float sample);
void init_low_pass_filter(ResistorCapacitor *lp, float cutoff_frequency, float sample_rate);
float apply_low_pass_filter(ResistorCapacitor *lp, float sample);
typedef struct {
float *buffer;
int write_idx; // Write position