File: fold.c

package info (click to toggle)
pd-lyonpotpourri 3.0.2-1
  • links: PTS, VCS
  • area: main
  • in suites: forky, sid, trixie
  • size: 3,724 kB
  • sloc: ansic: 24,685; makefile: 106; perl: 12
file content (24 lines) | stat: -rw-r--r-- 491 bytes parent folder | download 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
 
#include "fftease.h"

/*
 * multiply current input I by window W (both of length Nw);
 * using modulus arithmetic, fold and rotate windowed input
 * into output array O of (FFT) length N according to current
 * input time n
 */
void lpp_fold( t_float *I, t_float *W, int Nw, t_float *O, int N, int n )
{
  int i;

  for ( i = 0; i < N; i++ )
    O[i] = 0.;

  while ( n < 0 )
    n += N;
  n %= N;
  for ( i = 0; i < Nw; i++ ) {
    O[n] += I[i]*W[i];
    if ( ++n == N )
      n = 0;
  }
}