57 lines
1.1 KiB
C
57 lines
1.1 KiB
C
#include "math.h"
|
|
|
|
#define LIMIT(v,l,u) ((v)<(l)?(l):((v)>(u)?(u):(v)))
|
|
#define DB2LIN(x) ((x) > -90 ? pow(10, (x) * 0.05) : 0)
|
|
|
|
/* frequency to rads/sec (angular frequency) */
|
|
#define ANGULAR(fc, fs) (2 * M_PI / (fs) * (fc))
|
|
#define ANGULAR_LIM(fc, fs) (2 * M_PI / (fs) * LIMIT((fc), 1, (fs)/2))
|
|
|
|
/* this is pretty gross;
|
|
* it's too easy to define BIQUAD_DOUBLE in one file and not another */
|
|
#ifdef BIQUAD_DOUBLE
|
|
typedef double bq_t;
|
|
#else
|
|
typedef float bq_t;
|
|
#endif
|
|
|
|
typedef struct {
|
|
bq_t a1, a2, b0, b1, b2, x1, x2, y1, y2;
|
|
} biquad;
|
|
|
|
typedef struct {
|
|
double b0, b1, b2, a0, a1, a2;
|
|
} biquad_interim;
|
|
|
|
static float
|
|
whitenoise();
|
|
|
|
static void
|
|
biquad_init(biquad *bq);
|
|
|
|
/* types: TODO: enum
|
|
0: peaking
|
|
1: lowshelf
|
|
2: highshelf
|
|
3: lowpass
|
|
4: highpass
|
|
5: allpass
|
|
6: bandpass 1
|
|
7: bandpass 2
|
|
8: notch
|
|
9: gain
|
|
*/
|
|
static biquad
|
|
biquad_gen(int type, double fc, double gain, double bw, double fs);
|
|
|
|
/* s-plane to z-plane */
|
|
static biquad_interim
|
|
design(double cw, double sw,
|
|
double num0, double num1, double num2,
|
|
double den0, double den1, double den2);
|
|
|
|
static bq_t
|
|
biquad_run(biquad *bq, bq_t x);
|
|
|
|
#include "crap_util_def.h"
|