static void calc_prediction_coef(sbr_info *sbr, qmf_t Xlow[MAX_NTSRHFG][64],
complex_t *alpha_0, complex_t *alpha_1, uint8_t k)
{
real_t tmp, mul;
acorr_coef ac;
auto_correlation(sbr, &ac, Xlow, k, sbr->numTimeSlotsRate + 6);
if (ac.det == 0)
{
RE(alpha_1[k]) = 0;
IM(alpha_1[k]) = 0;
} else {
mul = DIV_R(REAL_CONST(1.0), ac.det);
tmp = (MUL_R(RE(ac.r01), RE(ac.r12)) - MUL_R(IM(ac.r01), IM(ac.r12)) - MUL_R(RE(ac.r02), RE(ac.r11)));
RE(alpha_1[k]) = MUL_R(tmp, mul);
tmp = (MUL_R(IM(ac.r01), RE(ac.r12)) + MUL_R(RE(ac.r01), IM(ac.r12)) - MUL_R(IM(ac.r02), RE(ac.r11)));
IM(alpha_1[k]) = MUL_R(tmp, mul);
}
if (RE(ac.r11) == 0)
{
RE(alpha_0[k]) = 0;
IM(alpha_0[k]) = 0;
} else {
mul = DIV_R(REAL_CONST(1.0), RE(ac.r11));
tmp = -(RE(ac.r01) + MUL_R(RE(alpha_1[k]), RE(ac.r12)) + MUL_R(IM(alpha_1[k]), IM(ac.r12)));
RE(alpha_0[k]) = MUL_R(tmp, mul);
tmp = -(IM(ac.r01) + MUL_R(IM(alpha_1[k]), RE(ac.r12)) - MUL_R(RE(alpha_1[k]), IM(ac.r12)));
IM(alpha_0[k]) = MUL_R(tmp, mul);
}
if ((MUL_R(RE(alpha_0[k]),RE(alpha_0[k])) + MUL_R(IM(alpha_0[k]),IM(alpha_0[k])) >= REAL_CONST(16)) ||
(MUL_R(RE(alpha_1[k]),RE(alpha_1[k])) + MUL_R(IM(alpha_1[k]),IM(alpha_1[k])) >= REAL_CONST(16)))
{
RE(alpha_0[k]) = 0;
IM(alpha_0[k]) = 0;
RE(alpha_1[k]) = 0;
IM(alpha_1[k]) = 0;
}
}
static void calc_prediction_coef_lp(sbr_info *sbr, qmf_t Xlow[MAX_NTSRHFG][64],
complex_t *alpha_0, complex_t *alpha_1, real_t *rxx)
{
uint8_t k;
real_t tmp, mul;
acorr_coef ac;
for (k = 1; k < sbr->f_master[0]; k++)
{
auto_correlation(sbr, &ac, Xlow, k, sbr->numTimeSlotsRate + 6);
if (ac.det == 0)
{
RE(alpha_0[k]) = 0;
RE(alpha_1[k]) = 0;
} else {
mul = DIV_R(REAL_CONST(1.0), ac.det);
tmp = MUL_R(RE(ac.r01), RE(ac.r22)) - MUL_R(RE(ac.r12), RE(ac.r02));
RE(alpha_0[k]) = -MUL_R(tmp, mul);
tmp = MUL_R(RE(ac.r01), RE(ac.r12)) - MUL_R(RE(ac.r02), RE(ac.r11));
RE(alpha_1[k]) = MUL_R(tmp, mul);
}
if ((RE(alpha_0[k]) >= REAL_CONST(4)) || (RE(alpha_1[k]) >= REAL_CONST(4)))
{
RE(alpha_0[k]) = REAL_CONST(0);
RE(alpha_1[k]) = REAL_CONST(0);
}
/* reflection coefficient */
if (RE(ac.r11) == 0)
{
rxx[k] = COEF_CONST(0.0);
} else {
rxx[k] = DIV_C(RE(ac.r01), RE(ac.r11));
rxx[k] = -rxx[k];
if (rxx[k] > COEF_CONST( 1.0)) rxx[k] = COEF_CONST(1.0);
if (rxx[k] < COEF_CONST(-1.0)) rxx[k] = COEF_CONST(-1.0);
}
}
}
/*
* Parameter:
* coderInfo(I)
* xr(I)
* xmin(O)
* quality(I)
*/
static void CalcAllowedDist(CoderInfo *coderInfo,
pow_t *xr2, real_32_t *xmin, real_32_t quality)
{
register int32_t sfb, start, end, l;
int32_t last = coderInfo->lastx;
int32_t lastsb = 0;
int32_t *cb_offset = coderInfo->sfb_offset;
int32_t num_cb = coderInfo->nr_of_sfb;
eng_t avgenrg = coderInfo->avgenrg;
static real_32_t realconst1 = REAL_CONST(0.075);
static real_32_t realconst2 = REAL_CONST(1.4);
static real_32_t realconst3 = REAL_CONST(0.4);
static real_32_t realconst4 = REAL_CONST(147.84); /* 132 * 1.12 */
for (sfb = 0; sfb < num_cb; sfb++) {
if (last > cb_offset[sfb])
lastsb = sfb;
}
for (sfb = 0; sfb < num_cb; sfb++) {
real_t thr;
real_32_t tmp;
eng_t enrg = 0;
start = cb_offset[sfb];
end = cb_offset[sfb + 1];
if (sfb > lastsb) {
xmin[sfb] = 0;
continue;
}
if (coderInfo->block_type != ONLY_SHORT_WINDOW) {
eng_t enmax = -1;
int32_t lmax;
lmax = start;
for (l = start; l < end; l++) {
if (enmax < xr2[l]) {
enmax = xr2[l];
lmax = l;
}
}
start = lmax - 2;
end = lmax + 3;
if (start < 0)
start = 0;
if (end > last)
end = last;
}
for (l = start; l < end; l++) {
enrg += xr2[l];
}
if ( (avgenrg == 0) || (enrg==0) )
thr = 0;
else {
thr = (avgenrg<<REAL_BITS)*(end-start)/enrg;
thr = faac_pow(thr, REAL_ICONST(sfb)/(lastsb*10)-realconst3);
}
tmp = DIV_R(REAL_ICONST(last-start),REAL_ICONST(last));
tmp = MUL_R(MUL_R(tmp,tmp),tmp) + realconst1;
thr = MUL_R(realconst2,thr) + tmp;
xmin[sfb] = DIV_R(DIV_R(realconst4,thr),quality);
#ifdef DUMP_XMIN
printf("xmin[%d] = %.8f\n",sfb,REAL2FLOAT(xmin[sfb]));
#endif
}
#ifdef DUMP_XMIN
// exit(1);
#endif
}
