/* sIgpAck
* for
* pure-data
* www.weiss-archiv.de */
#include "m_pd.h"
#include <math.h>
#ifdef _MSC_VER
#pragma warning( disable : 4244 )
#pragma warning( disable : 4305 )
#define M_PI 3.14159265358979323846
#endif
/* ------------------------ freqshift~ ----------------------------- */
/* frequency shifter */
/* code from swh_plugins by steve harris www.plugins.org.uk */
#define SIN_T_SIZE 64
#define D_SIZE 256
#define NZEROS 200
static t_class *freqshift_tilde_class;
typedef struct _freqshift_tilde
{
t_object x_obj;
t_float x_shift;//[0 - 5000]
float *x_delay;
unsigned int x_dptr;
t_float x_fs;
t_float x_last_shift;
t_float x_phi;
float *x_sint;
float x_f;
} t_freqshift_tilde;
static void *freqshift_tilde_new(t_floatarg shift)
{
unsigned int i;
t_freqshift_tilde *x = (t_freqshift_tilde *)pd_new(freqshift_tilde_class);
//x->x_shift = shift;
outlet_new(&x->x_obj, gensym("signal"));
outlet_new(&x->x_obj, gensym("signal"));
floatinlet_new(&x->x_obj, &x->x_shift);
x->x_fs = sys_getsr();
x->x_delay = (float *)getbytes(D_SIZE * sizeof(float));
x->x_sint = (float *)getbytes(SIN_T_SIZE * sizeof(float));
x->x_dptr = 0;
x->x_phi = 0.0f;
x->x_last_shift = 0.0f;
x->x_f = 0;
for (i = 0; i < SIN_T_SIZE; i++) {
x->x_sint[i] = sin(2.0f * M_PI * (float)i / (float)SIN_T_SIZE);
}
if (shift) x->x_shift = shift;
else x->x_shift = 0;
return (x);
}
/* The non-zero taps of the Hilbert transformer */
static float xcoeffs[] = {
+0.0008103736f, +0.0008457886f, +0.0009017196f, +0.0009793364f,
+0.0010798341f, +0.0012044365f, +0.0013544008f, +0.0015310235f,
+0.0017356466f, +0.0019696659f, +0.0022345404f, +0.0025318040f,
+0.0028630784f, +0.0032300896f, +0.0036346867f, +0.0040788644f,
+0.0045647903f, +0.0050948365f, +0.0056716186f, +0.0062980419f,
+0.0069773575f, +0.0077132300f, +0.0085098208f, +0.0093718901f,
+0.0103049226f, +0.0113152847f, +0.0124104218f, +0.0135991079f,
+0.0148917649f, +0.0163008758f, +0.0178415242f, +0.0195321089f,
+0.0213953037f, +0.0234593652f, +0.0257599469f, +0.0283426636f,
+0.0312667947f, +0.0346107648f, +0.0384804823f, +0.0430224431f,
+0.0484451086f, +0.0550553725f, +0.0633242001f, +0.0740128560f,
+0.0884368322f, +0.1090816773f, +0.1412745301f, +0.1988673273f,
+0.3326528346f, +0.9997730178f, -0.9997730178f, -0.3326528346f,
-0.1988673273f, -0.1412745301f, -0.1090816773f, -0.0884368322f,
-0.0740128560f, -0.0633242001f, -0.0550553725f, -0.0484451086f,
-0.0430224431f, -0.0384804823f, -0.0346107648f, -0.0312667947f,
-0.0283426636f, -0.0257599469f, -0.0234593652f, -0.0213953037f,
-0.0195321089f, -0.0178415242f, -0.0163008758f, -0.0148917649f,
-0.0135991079f, -0.0124104218f, -0.0113152847f, -0.0103049226f,
-0.0093718901f, -0.0085098208f, -0.0077132300f, -0.0069773575f,
-0.0062980419f, -0.0056716186f, -0.0050948365f, -0.0045647903f,
-0.0040788644f, -0.0036346867f, -0.0032300896f, -0.0028630784f,
-0.0025318040f, -0.0022345404f, -0.0019696659f, -0.0017356466f,
-0.0015310235f, -0.0013544008f, -0.0012044365f, -0.0010798341f,
-0.0009793364f, -0.0009017196f, -0.0008457886f, -0.0008103736f,
};
static float f_clamp(float x, float a, float b)
{
const float x1 = fabs(x - a);
const float x2 = fabs(x - b);
x = x1 + a + b;
x -= x2;
x *= 0.5;
return x;
}
// Round float to int using IEEE int* hack
static int f_round(float f) {
f += (3<<22);
return *((int*)&f) - 0x4b400000;
}
// Cubic interpolation function
static float cube_interp(const float fr, const float inm1, const float
in, const float inp1, const float inp2)
{
return in + 0.5f * fr * (inp1 - inm1 +
fr * (4.0f * inp1 + 2.0f * inm1 - 5.0f * in - inp2 +
fr * (3.0f * (in - inp1) - inm1 + inp2)));
}
static t_int *freqshift_tilde_perform(t_int *w)
{
t_freqshift_tilde *x = (t_freqshift_tilde *)(w[1]);
t_float *in = (t_float *)(w[2]);
t_float *out1 = (t_float *)(w[3]);
t_float *out2 = (t_float *)(w[4]);
int n = (int)(w[5]);
float f, hilb, rm1, rm2, frac_p;
float shift_i = x->x_last_shift;
float sample_count = sys_getblksize();
unsigned int i;
int int_p;
const float shift_c = f_clamp(x->x_shift, 0.0f, 10000.0f);
const float shift_inc = (shift_c - x->x_last_shift) / (float)sample_count;
const float freq_fix = (float)SIN_T_SIZE / x->x_fs;
while (n--)
{
f = *in++;
x->x_delay[x->x_dptr] = f;
/* Perform the Hilbert FIR convolution
* (probably FFT would be faster) */
hilb = 0.0f;
for (i = 0; i <= NZEROS/2; i++) {
hilb += (xcoeffs[i] * x->x_delay[(x->x_dptr - i*2) & (D_SIZE - 1)]);
}
/* Calcuate the table positions for the sine modulator */
int_p = f_round(floor(x->x_phi));
/* Calculate ringmod1, the transformed input modulated with a shift Hz
* sinewave. This creates a +180 degree sideband at source-shift Hz and
* a 0 degree sindeband at source+shift Hz */
frac_p = x->x_phi - int_p;
rm1 = hilb * cube_interp(frac_p, x->x_sint[int_p], x->x_sint[int_p+1],
x->x_sint[int_p+2], x->x_sint[int_p+3]);
/* Calcuate the table positions for the cosine modulator */
int_p = (int_p + SIN_T_SIZE / 4) & (SIN_T_SIZE - 1);
/* Calculate ringmod2, the delayed input modulated with a shift Hz
* cosinewave. This creates a 0 degree sideband at source+shift Hz
* and a -180 degree sindeband at source-shift Hz */
rm2 = x->x_delay[(x->x_dptr - 100) & (D_SIZE - 1)] * cube_interp(frac_p,
x->x_sint[int_p], x->x_sint[int_p+1], x->x_sint[int_p+2], x->x_sint[int_p+3]);
/* Output the sum and differences of the ringmods. The +/-180 degree
* sidebands cancel (more of less) and just leave the shifted
* components */
*out1++ = (rm2 - rm1) * 0.5f; /*downshifting*/
*out2++ = (rm2 + rm1) * 0.5f; /*upshifting*/
x->x_dptr = (x->x_dptr + 1) & (D_SIZE - 1);
x->x_phi += shift_i * freq_fix;
while (x->x_phi > SIN_T_SIZE) {
x->x_phi -= SIN_T_SIZE;
}
shift_i += shift_inc;
}
return (w+6);
}
static void freqshift_tilde_dsp(t_freqshift_tilde *x, t_signal **sp)
{
dsp_add(freqshift_tilde_perform, 5, x, sp[0]->s_vec, sp[1]->s_vec, sp[2]->s_vec, sp[0]->s_n);
}
static void freqshift_tilde_free(t_freqshift_tilde *x)
{
if(x->x_delay)
freebytes(x->x_delay, D_SIZE * sizeof(float));
if(x->x_sint)
freebytes(x->x_sint, SIN_T_SIZE + 4 * sizeof(float));
}
void freqshift_tilde_setup(void)
{
freqshift_tilde_class = class_new(gensym("freqshift~"), (t_newmethod)freqshift_tilde_new, (t_method)freqshift_tilde_free,
sizeof(t_freqshift_tilde), 0, A_DEFFLOAT, 0);
CLASS_MAINSIGNALIN(freqshift_tilde_class, t_freqshift_tilde, x_f);
class_addmethod(freqshift_tilde_class, (t_method)freqshift_tilde_dsp, gensym("dsp"), 0);
}