table_type get_window_samples(LVAL window, sample_type **samples, long *len)
{
table_type result = NULL;
if (soundp(window)) {
sound_type window_sound = getsound(window);
xlprot1(window); /* maybe not necessary */
result = sound_to_table(window_sound);
xlpop();
*samples = result->samples;
*len = (long) (result->length + 0.5);
}
return result;
}
sound_type snd_make_convolve(sound_type x_snd, sound_type h_snd)
{
register convolve_susp_type susp;
rate_type sr = x_snd->sr;
time_type t0 = x_snd->t0;
sample_type scale_factor = 1.0F;
time_type t0_min = t0;
table_type table;
double log_len;
falloc_generic(susp, convolve_susp_node, "snd_make_convolve");
table = sound_to_table(h_snd);
susp->h_len = table->length;
log_len = log(table->length) / M_LN2; /* compute log-base-2(length) */
susp->M = (int) log_len;
if (susp->M != log_len) susp->M++; /* round up */
susp->N = 1 << susp->M; /* size of data blocks */
susp->M++; /* M = log2(2 * N) */
susp->H = (sample_type *) calloc(2 * susp->N, sizeof(susp->H[0]));
if (!susp->H) {
xlabort("memory allocation failure in convolve");
}
memcpy(susp->H, table->samples, sizeof(susp->H[0]) * susp->N);
table_unref(table); /* don't need table now */
/* remaining N samples are already zero-filled */
if (fftInit(susp->M)) {
free(susp->H);
xlabort("fft initialization error in convolve");
}
rffts(susp->H, susp->M, 1);
susp->X = (sample_type *) calloc(2 * susp->N, sizeof(susp->X[0]));
susp->R = (sample_type *) calloc(2 * susp->N, sizeof(susp->R[0]));
if (!susp->X || !susp->R) {
free(susp->H);
if (susp->X) free(susp->X);
if (susp->R) free(susp->R);
xlabort("memory allocation failed in convolve");
}
susp->R_current = susp->R + susp->N;
susp->susp.fetch = &convolve_s_fetch;
susp->terminate_cnt = UNKNOWN;
/* handle unequal start times, if any */
if (t0 < x_snd->t0) sound_prepend_zeros(x_snd, t0);
/* minimum start time over all inputs: */
t0_min = min(x_snd->t0, t0);
/* how many samples to toss before t0: */
susp->susp.toss_cnt = (long) ((t0 - t0_min) * sr + 0.5);
if (susp->susp.toss_cnt > 0) {
susp->susp.keep_fetch = susp->susp.fetch;
susp->susp.fetch = convolve_toss_fetch;
}
/* initialize susp state */
susp->susp.free = convolve_free;
susp->susp.sr = sr;
susp->susp.t0 = t0;
susp->susp.mark = convolve_mark;
susp->susp.print_tree = convolve_print_tree;
susp->susp.name = "convolve";
susp->logically_stopped = false;
susp->susp.log_stop_cnt = logical_stop_cnt_cvt(x_snd);
susp->susp.current = 0;
susp->x_snd = x_snd;
susp->x_snd_cnt = 0;
return sound_create((snd_susp_type)susp, t0, sr, scale_factor);
}
