From fe63e6bf79bd34ac5acc443699cb1ea8b54c06f5 Mon Sep 17 00:00:00 2001 From: Dimitri Sokolyuk Date: Wed, 10 Sep 2014 11:40:34 +0000 Subject: move normalization factor into window function --- fft.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/fft.c b/fft.c index ea9ba2c..46b91d7 100644 --- a/fft.c +++ b/fft.c @@ -43,8 +43,10 @@ hamming(size_t n) p = calloc(n, sizeof(double)); assert(p); - for (i = 0; i < n; i++) + for (i = 0; i < n; i++) { p[i] = 0.54 - 0.46 * cos((2 * M_PI * i) / (n - 1)); + p[i] /= INT16_MAX; + } return p; } @@ -91,8 +93,7 @@ exec_fft(struct fft *p, int16_t *data, double *out, enum fft_chan chan) int i; for (i = 0; i < p->n; i++) - p->in[i] = p->window[i] * data[2 * i + chan] - / (double)INT16_MAX; + p->in[i] = p->window[i] * data[2 * i + chan]; fftw_execute(p->plan); -- cgit v1.2.3