pipewire/spa/plugins/audioconvert/crossover.c
2023-06-30 17:49:29 +02:00

64 lines
1.3 KiB
C

/* Copyright (c) 2013 The Chromium OS Authors. All rights reserved.
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include <float.h>
#include <string.h>
#include "crossover.h"
void lr4_set(struct lr4 *lr4, enum biquad_type type, float freq)
{
biquad_set(&lr4->bq, type, freq);
lr4->x1 = 0;
lr4->x2 = 0;
lr4->y1 = 0;
lr4->y2 = 0;
lr4->z1 = 0;
lr4->z2 = 0;
lr4->active = true;
}
void lr4_process(struct lr4 *lr4, float *dst, const float *src, const float vol, int samples)
{
float x1 = lr4->x1;
float x2 = lr4->x2;
float y1 = lr4->y1;
float y2 = lr4->y2;
float b0 = lr4->bq.b0;
float b1 = lr4->bq.b1;
float b2 = lr4->bq.b2;
float a1 = lr4->bq.a1;
float a2 = lr4->bq.a2;
float x, y, z;
int i;
if (vol == 0.0f) {
memset(dst, 0, samples * sizeof(float));
return;
} else if (!lr4->active) {
if (src != dst || vol != 1.0f) {
for (i = 0; i < samples; i++)
dst[i] = src[i] * vol;
}
return;
}
for (i = 0; i < samples; i++) {
x = src[i];
y = b0 * x + x1;
x1 = b1 * x - a1 * y + x2;
x2 = b2 * x - a2 * y;
z = b0 * y + y1;
y1 = b1 * y - a1 * z + y2;
y2 = b2 * y - a2 * z;
dst[i] = z * vol;
}
#define F(x) (-FLT_MIN < (x) && (x) < FLT_MIN ? 0.0f : (x))
lr4->x1 = F(x1);
lr4->x2 = F(x2);
lr4->y1 = F(y1);
lr4->y2 = F(y2);
#undef F
}