not sure

dsp/filters.c

@@ -0,0 +1,16 @@
+#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));
+}