diff options
Diffstat (limited to 'flib/src/cross~.c')
| -rw-r--r-- | flib/src/cross~.c | 102 |
1 files changed, 90 insertions, 12 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); |