diff options
Diffstat (limited to 'externals/grill/fftease/src/fold.c')
| -rw-r--r-- | externals/grill/fftease/src/fold.c | 32 |
1 files changed, 23 insertions, 9 deletions
diff --git a/externals/grill/fftease/src/fold.c b/externals/grill/fftease/src/fold.c index 0ecee5d6..2c380032 100644 --- a/externals/grill/fftease/src/fold.c +++ b/externals/grill/fftease/src/fold.c @@ -6,19 +6,33 @@ */ void fold( float *I, float *W, int Nw, float *O, int N, int n ) { - int i; + for ( i = 0; i < N; i++ ) O[i] = 0.; - for ( i = 0; i < N; i++ ) - O[i] = 0.; - - while ( n < 0 ) - n += N; + while ( n < 0 ) n += N; n %= N; + for ( i = 0; i < Nw; i++ ) { - O[n] += I[i]*W[i]; - if ( ++n == N ) - n = 0; + O[n] += I[i]*W[i]; + if ( ++n == N ) n = 0; + } +} + + +/* + * input I is a folded spectrum of length N; output O and + * synthesis window W are of length Nw--overlap-add windowed, + * unrotated, unfolded input data into output O + */ +void overlapadd( float *I, int N, float *W, float *O, int Nw, int n ) +{ + int i ; + while ( n < 0 ) n += N ; + n %= N ; + + for ( i = 0 ; i < Nw ; i++ ) { + O[i] += I[n]*W[i] ; + if ( ++n == N ) n = 0 ; } } |