//============================================================================
//函数功能:找到语音因子
//函数参数:"exc[]"表示因子，作为输入参数；"Q_exc"表示激励，表示输入参数；"gain_pit"
// 表示增益音高，作为输入参数；"code[]"表示固定码本激励，作为输入参数；
// "gain_code"表示编码增益，作为输入参数；"L_subfr"表示子帧长度
//============================================================================
int16 voice_factor( /* (o) Q15 : factor (-1=unvoiced to 1=voiced) */
int16 exc[], /* (i) Q_exc : pitch excitation */
int16 Q_exc, /* (i) : exc format */
int16 gain_pit, /* (i) Q14 : gain of pitch */
int16 code[], /* (i) Q9 : Fixed codebook excitation */
int16 gain_code, /* (i) Q0 : gain of code */
int16 L_subfr /* (i) : subframe length */
)
{
int16 i, tmp, exp, ener1, exp1, ener2, exp2;
int32 L_tmp;
ener1 = extract_h(Dot_product12(exc, exc, L_subfr, &exp1));
exp1 = sub_int16(exp1, Q_exc << 1);
L_tmp = mul_16by16_to_int32(gain_pit, gain_pit);
exp = normalize_amr_wb(L_tmp);
tmp = (int16)((L_tmp << exp) >> 16);
ener1 = mult_int16(ener1, tmp);
exp1 -= (exp + 10); /* 10 -> gain_pit Q14 to Q9 */
ener2 = extract_h(Dot_product12(code, code, L_subfr, &exp2));
exp = norm_s(gain_code);
tmp = shl_int16(gain_code, exp);
tmp = mult_int16(tmp, tmp);
ener2 = mult_int16(ener2, tmp);
exp2 -= (exp << 1);
i = exp1 - exp2;
if (i >= 0)
{
ener1 >>= 1;
ener2 >>= (i + 1);
}
void agc2_amr_wb(
int16 * sig_in, /* (i) : postfilter input signal */
int16 * sig_out, /* (i/o) : postfilter output signal */
int16 l_trm /* (i) : subframe size */
)
{
int16 i, exp;
int16 gain_in, gain_out, g0;
int32 s;
int16 temp;
/* calculate gain_out with exponent */
temp = sig_out[0] >> 2;
s = fxp_mul_16by16(temp, temp) << 1;
for (i = 1; i < l_trm; i++)
{
temp = sig_out[i] >> 2;
s = mac_16by16_to_int32(s, temp, temp);
}
if (s == 0)
{
return;
}
exp = normalize_amr_wb(s) - 1;
gain_out = amr_wb_round(s << exp);
/* calculate gain_in with exponent */
temp = sig_in[0] >> 2;
s = mul_16by16_to_int32(temp, temp);
for (i = 1; i < l_trm; i++)
{
temp = sig_in[i] >> 2;
s = mac_16by16_to_int32(s, temp, temp);
}
if (s == 0)
{
g0 = 0;
}
else
{
i = normalize_amr_wb(s);
gain_in = amr_wb_round(s << i);
exp -= i;
/*
* g0 = sqrt(gain_in/gain_out)
*/
s = div_16by16(gain_out, gain_in);
s = shl_int32(s, 7); /* s = gain_out / gain_in */
s = shr_int32(s, exp); /* add exponent */
s = one_ov_sqrt(s);
g0 = amr_wb_round(shl_int32(s, 9));
}
/* sig_out(n) = gain(n) sig_out(n) */
for (i = 0; i < l_trm; i++)
{
sig_out[i] = extract_h(shl_int32(fxp_mul_16by16(sig_out[i], g0), 3));
}
return;
}
