rockbox/apps/codecs/libwmapro/wmapro_math.h
2010-07-12 15:41:10 +00:00

51 lines
1.4 KiB
C

#ifndef _WMAPRO_MATH_H_
#define _WMAPRO_MATH_H_
#include <inttypes.h>
#include "types.h"
#define fixtof16(x) (float)((float)(x) / (float)(1 << 16))
#define fixtof31(x) (float)((float)(x) / (float)(1 << 31))
#define ftofix16(x) ((int32_t)((x) * (float)(1 << 16) + ((x) < 0 ? -0.5:0.5)))
#define ftofix31(x) ((int32_t)((x) * (float)(1 << 31) + ((x) < 0 ? -0.5:0.5)))
static inline FIXED fixmulshift(FIXED x, FIXED y, int shamt)
{
int64_t temp;
temp = x;
temp *= y;
temp >>= shamt;
return (int32_t)temp;
}
static inline void vector_fixmul_window(FIXED *dst, const FIXED *src0,
const FIXED *src1, const FIXED *win,
FIXED add_bias, int len)
{
int i, j;
dst += len;
win += len;
src0+= len;
for(i=-len, j=len-1; i<0; i++, j--) {
FIXED s0 = src0[i];
FIXED s1 = src1[j];
FIXED wi = win[i];
FIXED wj = win[j];
dst[i] = fixmulshift(s0,-1*wj,31) - fixmulshift(s1,-1*wi,31) + (add_bias<<16);
dst[j] = fixmulshift(s0,-1*wi,31) + fixmulshift(s1,-1*wj,31) + (add_bias<<16);
}
}
static inline void vector_fixmul_scalar(FIXED *dst, const FIXED *src, FIXED mul,
int len, int shift)
{
int i;
for(i=0; i<len; i++)
dst[i] = fixmulshift(src[i],mul,shift);
}
#endif /* _WMAPRO_MATH_H_ */