main()
{
Word16 out;
Word32 in = 0x11112222;
out=sature(in);
return ;
}
/*----------------------------------------------------------------------------
* filt_mu - tilt filtering with : (1 + mu z-1) * (1/1-|mu|)
* computes y[n] = (1/1-|mu|) (x[n]+mu*x[n-1])
*----------------------------------------------------------------------------
*/
static void filt_mu(
Word16 *sig_in, /* input : input signal (beginning at sample -1) */
Word16 *sig_out, /* output: output signal */
Word16 parcor0 /* input : parcor0 (mu = parcor0 * gamma3) */
)
{
int n;
Word16 mu, mu2, ga, temp;
Word32 L_acc, L_temp, L_fact;
Word16 fact, sh_fact1;
Word16 *ptrs;
if(parcor0 > 0) {
mu = mult_r(parcor0, GAMMA3_PLUS);
/* GAMMA3_PLUS < 0.5 */
sh_fact1 = 15; /* sh_fact + 1 */
fact = (Word16)0x4000; /* 2**sh_fact */
L_fact = (Word32)0x00004000L;
}
else {
mu = mult_r(parcor0, GAMMA3_MINUS);
/* GAMMA3_MINUS < 0.9375 */
sh_fact1 = 12; /* sh_fact + 1 */
fact = (Word16)0x0800; /* 2**sh_fact */
L_fact = (Word32)0x00000800L;
}
temp = sub(1, abs_s(mu));
mu2 = add(32767, temp); /* 2**15 (1 - |mu|) */
ga = div_s(fact, mu2); /* 2**sh_fact / (1 - |mu|) */
ptrs = sig_in; /* points on sig_in(-1) */
mu = shr(mu, 1); /* to avoid overflows */
for(n=0; n<L_SUBFR; n++) {
temp = *ptrs++;
L_temp = L_deposit_l(*ptrs);
L_acc = L_shl(L_temp, 15); /* sig_in(n) * 2**15 */
L_temp = L_mac(L_acc, mu, temp);
L_temp = L_add(L_temp, 0x00004000L);
temp = extract_l(L_shr(L_temp,15));
/* ga x temp x 2 with rounding */
L_temp = L_add(L_mult(temp, ga),L_fact);
L_temp = L_shr(L_temp, sh_fact1); /* mult. temp x ga */
sig_out[n] = sature(L_temp);
}
return;
}
