diff options
Diffstat (limited to 'freqshift~.c')
| -rw-r--r-- | freqshift~.c | 197 |
1 files changed, 197 insertions, 0 deletions
diff --git a/freqshift~.c b/freqshift~.c new file mode 100644 index 0000000..026e4cb --- /dev/null +++ b/freqshift~.c @@ -0,0 +1,197 @@ +/* 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);
+}
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