mirror of
https://github.com/radio95-rnt/fm95.git
synced 2026-02-26 19:23:51 +01:00
16 lines
526 B
C
16 lines
526 B
C
#include "filters.h"
|
|
|
|
void init_preemphasis(ResistorCapacitor *filter, float tau, float sample_rate) {
|
|
filter->prev_sample = 0.0f;
|
|
filter->alpha = expf(-1 / (tau*sample_rate));
|
|
filter->gain = 1.0f / sqrtf(1.0f - filter->alpha);
|
|
}
|
|
float apply_preemphasis(ResistorCapacitor *filter, float sample) {
|
|
float out = (sample - filter->alpha * filter->prev_sample) * filter->gain;
|
|
filter->prev_sample = sample;
|
|
return out;
|
|
}
|
|
|
|
float hard_clip(float sample, float threshold) {
|
|
return fmaxf(-threshold, fminf(threshold, sample));
|
|
} |