#define WFRAC_BITS 16 /* fractional bits for window */
#endif
+#define IMDCT_SCALAR 1.759
+
#define FRAC_ONE (1 << FRAC_BITS)
#define FIX(a) ((int)((a) * FRAC_ONE))
double value = i / 4;
double f, fm;
int e, m;
- f = value * cbrtf(value) * pow(2, (i & 3) * 0.25);
+ f = value / IMDCT_SCALAR * cbrtf(value) * pow(2, (i & 3) * 0.25);
fm = frexp(f, &e);
m = (uint32_t)(fm * (1LL << 31) + 0.5);
e += FRAC_BITS - 31 + 5 - 100;
}
for (exponent = 0; exponent < 512; exponent++) {
for (value = 0; value < 16; value++) {
- double f = (double)value * cbrtf(value) * pow(2, (exponent - 400) * 0.25 + FRAC_BITS + 5);
+ double f = (double)value * cbrtf(value) * pow(2, (exponent - 400) * 0.25 + FRAC_BITS + 5) / IMDCT_SCALAR;
expval_table_fixed[exponent][value] = llrint(f);
expval_table_float[exponent][value] = f;
}
else if (i < 18) d = 1;
}
//merge last stage of imdct into the window coefficients
- d *= 0.5 / cos(M_PI * (2 * i + 19) / 72);
+ d *= 0.5 * IMDCT_SCALAR / cos(M_PI * (2 * i + 19) / 72);
if (j == 2)
RENAME(ff_mdct_win)[j][i/3] = FIXHR((d / (1<<5)));