diff options
Diffstat (limited to 'src/post/audio/window.c')
| -rw-r--r-- | src/post/audio/window.c | 26 |
1 files changed, 13 insertions, 13 deletions
diff --git a/src/post/audio/window.c b/src/post/audio/window.c index fdea90590..ca58152d5 100644 --- a/src/post/audio/window.c +++ b/src/post/audio/window.c @@ -1,5 +1,5 @@ /*============================================================================= - * + * * This software has been released under the terms of the GNU Public * license. See http://www.gnu.org/copyleft/gpl.html for details. * @@ -39,7 +39,7 @@ void boxcar(int n, _ftype_t* w) /* * Triang a.k.a Bartlett * - * | (N-1)| + * | (N-1)| * 2 * |k - -----| * | 2 | * w = 1.0 - --------------- @@ -53,7 +53,7 @@ void triang(int n, _ftype_t* w) _ftype_t k2 = 1/((_ftype_t)n + k1); int end = (n + 1) >> 1; int i; - + /* Calculate window coefficients */ for (i=0 ; i<end ; i++) w[i] = w[n-i-1] = (2.0*((_ftype_t)(i+1))-(1.0-k1))*k2; @@ -72,7 +72,7 @@ void hanning(int n, _ftype_t* w) { int i; _ftype_t k = 2*M_PI/((_ftype_t)(n+1)); /* 2*pi/(N+1) */ - + /* Calculate window coefficients */ for (i=0; i<n; i++) *w++ = 0.5*(1.0 - cos(k*(_ftype_t)(i+1))); @@ -131,22 +131,22 @@ void flattop(int n,_ftype_t* w) int i; _ftype_t k1 = 2*M_PI/((_ftype_t)(n-1)); /* 2*pi/(N-1) */ _ftype_t k2 = 2*k1; /* 4*pi/(N-1) */ - + /* Calculate window coefficients */ for (i=0; i<n; i++) *w++ = 0.2810638602 - 0.5208971735*cos(k1*(_ftype_t)i) + 0.1980389663*cos(k2*(_ftype_t)i); } -/* Computes the 0th order modified Bessel function of the first kind. - * (Needed to compute Kaiser window) - * +/* Computes the 0th order modified Bessel function of the first kind. + * (Needed to compute Kaiser window) + * * y = sum( (x/(2*n))^2 ) * n */ #define BIZ_EPSILON 1E-21 /* Max error acceptable */ static _ftype_t besselizero(_ftype_t x) -{ +{ _ftype_t temp; _ftype_t sum = 1.0; _ftype_t u = 1.0; @@ -175,10 +175,10 @@ static _ftype_t besselizero(_ftype_t x) * Gold (Theory and Application of DSP) under Kaiser windows for more * about Beta. The following table from Rabiner and Gold gives some * feel for the effect of Beta: - * + * * All ripples in dB, width of transition band = D*N where N = window * length - * + * * BETA D PB RIP SB RIP * 2.120 1.50 +-0.27 -30 * 3.384 2.23 0.0864 -40 @@ -195,8 +195,8 @@ void kaiser(int n, _ftype_t* w, _ftype_t b) _ftype_t k1 = 1.0/besselizero(b); int k2 = 1 - (n & 1); int end = (n + 1) >> 1; - int i; - + int i; + /* Calculate window coefficients */ for (i=0 ; i<end ; i++){ tmp = (_ftype_t)(2*i + k2) / ((_ftype_t)n - 1.0); |