This is reverb.c in view mode; [Download] [Up]
#include <stdio.h>
#include <math.h>
#include <carl/carl.h>
main(narg,argv) int narg; char *argv[]; {
register int i, j, delay, iter;
register float *buf, scale;
float input, output, gain;
float thresh = 1e-6; /* cutoff threshhold for reverb tail (-60dB) */
if (narg < 3) {
fprintf(stderr,"Usage: comb gain delay\n");
exit(1);
}
gain = expr(argv[1]);
if (exprerr) {
fprintf(stderr, "Illegal gain expression '%s'\n",argv[1]);
exit(1);
}
if (fabs( (double) gain) >= 1.0) {
fprintf(stderr,"Illegal gain = %f\n",gain);
exit(1);
}
delay = expr(argv[2]);
if (exprerr) {
fprintf(stderr, "Illegal delay expression '%s'\n",argv[1]);
exit(1);
}
if (delay<1 || delay>100000) {
fprintf(stderr,"Illegal delay = %d\n",delay);
exit(1);
}
if (isatty(0)) {
fprintf(stderr,"comb input must be a file or pipe.\n");
exit(1);
}
buf = (float *) calloc(delay, sizeof(float)); /* allocate delay buffer */
i = -1;
scale = 1./(1.+gain);
if (isatty(1)) { /* output in ASCII on screen */
while ( getfloat(&input) > 0 ) {
if (++i >= delay)
i -= delay;
output = *(buf+i) + input;
printf("%f\n",output);
*(buf+i) = *(buf+i) * gain - input * scale;
}
iter = delay * log( (double) thresh)/log( (double) gain);
for (j = 0; j < iter; j++) {
if (++i >= delay)
i -= delay;
printf("%f\n",*(buf+i));
*(buf+i) = *(buf+i) * gain;
}
} else { /* output in binary to stdout */
while ( getfloat(&input) > 0 ) {
if (++i >= delay)
i -= delay;
output = *(buf+i) - input;
putfloat( &output );
*(buf+i) = *(buf+i) * gain + input * scale;
}
iter = delay * log( (double) thresh)/log( (double) gain);
for (j = 0; j < iter; j++) {
if (++i >= delay)
i -= delay;
putfloat( buf+i );
*(buf+i) = *(buf+i) * gain;
}
flushfloat();
}
exit(0);
}
These are the contents of the former NiCE NeXT User Group NeXTSTEP/OpenStep software archive, currently hosted by Netfuture.ch.