boo/soxr/src/rdft.h

32 lines
825 B
C

/* SoX Resampler Library Copyright (c) 2007-13 robs@users.sourceforge.net
* Licence for this file: LGPL v2.1 See LICENCE for details. */
void ORDERED_CONVOLVE(int n, void * not_used, DFT_FLOAT * a, const DFT_FLOAT * b)
{
int i;
a[0] *= b[0];
a[1] *= b[1];
for (i = 2; i < n; i += 2) {
DFT_FLOAT tmp = a[i];
a[i ] = b[i ] * tmp - b[i+1] * a[i+1];
a[i+1] = b[i+1] * tmp + b[i ] * a[i+1];
}
(void)not_used;
}
void ORDERED_PARTIAL_CONVOLVE(int n, DFT_FLOAT * a, const DFT_FLOAT * b)
{
int i;
a[0] *= b[0];
for (i = 2; i < n; i += 2) {
DFT_FLOAT tmp = a[i];
a[i ] = b[i ] * tmp - b[i+1] * a[i+1];
a[i+1] = b[i+1] * tmp + b[i ] * a[i+1];
}
a[1] = b[i] * a[i] - b[i+1] * a[i+1];
}
#undef ORDERED_CONVOLVE
#undef ORDERED_PARTIAL_CONVOLVE
#undef DFT_FLOAT