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authorHans-Christoph Steiner <eighthave@users.sourceforge.net>2006-02-09 16:18:39 +0000
committerHans-Christoph Steiner <eighthave@users.sourceforge.net>2006-02-09 16:18:39 +0000
commitb418fb91e7bb45d7b5f1eb8b19703441ae94eb13 (patch)
tree3f4a32d0b99d4ea0ac602bec59f0d2accba46719 /lib/makewindows.c
got everything building and working, including building single-object/single-file objects with a shared dylib. Now got to get it integrated into the build systemsvn2git-root
svn path=/trunk/externals/fftease/; revision=4574
Diffstat (limited to 'lib/makewindows.c')
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1 files changed, 1 insertions, 0 deletions
diff --git a/lib/makewindows.c b/lib/makewindows.c
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+#include "fftease.h" void makewindows( float *H, float *A, float *S, int Nw, int N, int I ) { int i ; float sum ; for ( i = 0 ; i < Nw ; i++ ) H[i] = A[i] = S[i] = 0.54 - 0.46*cos( TWOPI*i/(Nw - 1) ) ; if ( Nw > N ) { float x ; x = -(Nw - 1)/2. ; for ( i = 0 ; i < Nw ; i++, x += 1. ) if ( x != 0. ) { A[i] *= N*sin( PI*x/N )/(PI*x) ; if ( I ) S[i] *= I*sin( PI*x/I )/(PI*x) ; } } for ( sum = i = 0 ; i < Nw ; i++ ) sum += A[i] ; for ( i = 0 ; i < Nw ; i++ ) { float afac = 2./sum ; float sfac = Nw > N ? 1./afac : afac ; A[i] *= afac ; S[i] *= sfac ; } if ( Nw <= N && I ) { for ( sum = i = 0 ; i < Nw ; i += I ) sum += S[i]*S[i] ; for ( sum = 1./sum, i = 0 ; i < Nw ; i++ ) S[i] *= sum ; } } void makehamming( float *H, float *A, float *S, int Nw, int N, int I, int odd ) { int i; float sum ; if (odd) { for ( i = 0 ; i < Nw ; i++ ) H[i] = A[i] = S[i] = sqrt(0.54 - 0.46*cos( TWOPI*i/(Nw - 1) )); } else { for ( i = 0 ; i < Nw ; i++ ) H[i] = A[i] = S[i] = 0.54 - 0.46*cos( TWOPI*i/(Nw - 1) ); } if ( Nw > N ) { float x ; x = -(Nw - 1)/2. ; for ( i = 0 ; i < Nw ; i++, x += 1. ) if ( x != 0. ) { A[i] *= N*sin( PI*x/N )/(PI*x) ; if ( I ) S[i] *= I*sin( PI*x/I )/(PI*x) ; } } for ( sum = i = 0 ; i < Nw ; i++ ) sum += A[i] ; for ( i = 0 ; i < Nw ; i++ ) { float afac = 2./sum ; float sfac = Nw > N ? 1./afac : afac ; A[i] *= afac ; S[i] *= sfac ; } if ( Nw <= N && I ) { for ( sum = i = 0 ; i < Nw ; i += I ) sum += S[i]*S[i] ; for ( sum = 1./sum, i = 0 ; i < Nw ; i++ ) S[i] *= sum ; } } void makehanning( float *H, float *A, float *S, int Nw, int N, int I, int odd ) { int i; float sum ; if (odd) { for ( i = 0 ; i < Nw ; i++ ) H[i] = A[i] = S[i] = sqrt(0.5 * (1. + cos(PI + TWOPI * i / (Nw - 1)))); } else { for ( i = 0 ; i < Nw ; i++ ) H[i] = A[i] = S[i] = 0.5 * (1. + cos(PI + TWOPI * i / (Nw - 1))); } if ( Nw > N ) { float x ; x = -(Nw - 1)/2. ; for ( i = 0 ; i < Nw ; i++, x += 1. ) if ( x != 0. ) { A[i] *= N*sin( PI*x/N )/(PI*x) ; if ( I ) S[i] *= I*sin( PI*x/I )/(PI*x) ; } } for ( sum = i = 0 ; i < Nw ; i++ ) sum += A[i] ; for ( i = 0 ; i < Nw ; i++ ) { float afac = 2./sum ; float sfac = Nw > N ? 1./afac : afac ; A[i] *= afac ; S[i] *= sfac ; } if ( Nw <= N && I ) { for ( sum = i = 0 ; i < Nw ; i += I ) sum += S[i]*S[i] ; for ( sum = 1./sum, i = 0 ; i < Nw ; i++ ) S[i] *= sum ; } } \ No newline at end of file