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authorJamie Bullock <postlude@users.sourceforge.net>2006-04-19 17:48:38 +0000
committerJamie Bullock <postlude@users.sourceforge.net>2006-04-19 17:48:38 +0000
commita1b3c0b4fa99bfd116f302fe74f1168c84d01f79 (patch)
tree2c5b948e0bdd920cab0f09de31cbbc42492421ce /flib/src
parent929b0f5f58583d2916800df9cdfd55c2953fe55f (diff)
Added frequency domain correlation to cross~
svn path=/trunk/externals/postlude/; revision=4940
Diffstat (limited to 'flib/src')
-rw-r--r--flib/src/cross~.c102
-rw-r--r--flib/src/flib.h2
2 files changed, 91 insertions, 13 deletions
diff --git a/flib/src/cross~.c b/flib/src/cross~.c
index d7ea4bb..2d06d9b 100644
--- a/flib/src/cross~.c
+++ b/flib/src/cross~.c
@@ -17,8 +17,14 @@
*/
-/*Calculate the (non optimized) cross correlation of two signal vectors*/
-/*Based on code by Phil Bourke */
+/*Calculate the cross correlation of two signal vectors*/
+
+/*The time domain implementation is based on code by Phil Bourke
+ * the frequency domain version is based on code by Charles Henry
+ *
+ * Specify a time delay as an argument for the time domain implemenation, for example an argument of 32 will give the correlation coefficients for delays from -32 to 32 samples between the two input vectors
+ *
+ * Specify an argument of 'f' for the frequency domain implementation*/
#include "flib.h"
@@ -30,9 +36,10 @@ typedef struct _cross {
t_object x_obj;
t_float f;
t_int delay;
+ t_int is_freq_domain;
} t_cross;
-static t_int *cross_perform(t_int *w)
+static t_int *cross_perform_time_domain(t_int *w)
{
t_sample *x = (t_sample *)(w[1]);
t_sample *y = (t_sample *)(w[2]);
@@ -45,12 +52,9 @@ static t_int *cross_perform(t_int *w)
if(maxdelay > N * .5){
maxdelay = N * .5;
post("cross~: invalid maxdelay, must be <= blocksize/2");
- }
- else if (!maxdelay){
- maxdelay = N * .5;
}
- /* Calculate the mean of the two series x[], y[] */
+/* Calculate the mean of the two series x[], y[] */
mx = 0;
my = 0;
for (i=0;i<N;i++) {
@@ -92,16 +96,90 @@ static t_int *cross_perform(t_int *w)
}
+
+t_int *cross_perform_freq_domain(t_int *w)
+{
+ t_cross *x = (t_cross *)(w[1]);
+
+ t_sample *sig1 = (t_sample *)(w[2]);
+ t_sample *sig2 = (t_sample *)(w[3]);
+ t_sample *out = (t_sample *)(w[4]);
+ long int size = (long int) w[5];
+ long int k = size/2;
+ float *expsig1 = NULL;
+ float *revsig2 = NULL;
+ float temp, temp2;
+ long int i=0;
+ int well_defined=1;
+ int qtr, thrqtr;
+
+// The two signals are created, nonzero on 0 to N/4 and 3N/4 to N
+// This will be revised
+
+ expsig1=(float *) alloca(size*sizeof(float));
+ revsig2=(float *) alloca(size*sizeof(float));
+ qtr = size/4;
+ thrqtr = 3*size/4;
+ for (i=0; i < qtr ; i++)
+ {
+ expsig1[i]=sig1[i];
+ revsig2[i]=0;
+ }
+ for (i=qtr; i < thrqtr ; i++)
+ {
+ expsig1[i]=sig1[i];
+ revsig2[i]=sig2[size-i];
+ }
+ for (i=thrqtr; i < size ; i++)
+ {
+ expsig1[i]=sig1[i];
+ revsig2[i]=0;
+ }
+
+ mayer_realfft(size, expsig1);
+ mayer_realfft(size, revsig2);
+ expsig1[0]*=revsig2[0];
+ expsig1[k]*=revsig2[k];
+ for(i=1; i < k; i++)
+ {
+ temp=expsig1[i];
+ temp2=expsig1[size-i];
+ expsig1[i]=temp*revsig2[i]-temp2*revsig2[size-i];
+ expsig1[size-i]=temp*revsig2[size-i]+temp2*revsig2[i];
+ }
+
+ mayer_realifft(size, expsig1);
+ for(i=0; i < size; i++)
+ {
+ out[i]=expsig1[i];
+ }
+
+ return(w+6);
+
+}
+
static void cross_dsp(t_cross *x, t_signal **sp)
{
- dsp_add(cross_perform, 5,
- sp[0]->s_vec, sp[1]->s_vec, sp[2]->s_vec, sp[0]->s_n, x->delay);
+ if(!x->is_freq_domain)
+ dsp_add(cross_perform_time_domain, 5,
+ sp[0]->s_vec, sp[1]->s_vec, sp[2]->s_vec, sp[0]->s_n, x->delay);
+ else
+ dsp_add(cross_perform_freq_domain, 5, x,
+ sp[0]->s_vec, sp[1]->s_vec, sp[2]->s_vec, sp[0]->s_n);
}
-static void *cross_new(t_floatarg f)
+static void *cross_new(t_symbol *s, t_int argc, t_atom *argv)
{
t_cross *x = (t_cross *)pd_new(cross_class);
- x->delay = (t_int)f;
+
+ if(atom_getsymbol(argv) == gensym("f")){
+ x->is_freq_domain = 1;
+ post("flib: cross: Frequency domain selected");
+ }
+ else {
+ x->delay = atom_getfloat(argv);
+ post("flib: cross: Time domain selected");
+ }
inlet_new(&x->x_obj, &x->x_obj.ob_pd, &s_signal, &s_signal);
outlet_new(&x->x_obj, &s_signal);
return (void *)x;
@@ -112,7 +190,7 @@ void cross_tilde_setup(void) {
cross_class = class_new(gensym("cross~"),
(t_newmethod)cross_new,
0, sizeof(t_cross),
- CLASS_DEFAULT, A_DEFFLOAT, 0);
+ CLASS_DEFAULT, A_GIMME, 0);
class_addmethod(cross_class,
(t_method)cross_dsp, gensym("dsp"), 0);
diff --git a/flib/src/flib.h b/flib/src/flib.h
index fba78f0..868f683 100644
--- a/flib/src/flib.h
+++ b/flib/src/flib.h
@@ -21,7 +21,7 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
#include <stdlib.h>
#include <string.h>
-#define VERSION "0.8"
+#define VERSION "0.82"
void sc_tilde_setup(void);
void ss_tilde_setup(void);