/*----------------------------------------------------------------------------
* Post - adaptive postfilter main function
*----------------------------------------------------------------------------
*/
void Post(
Word16 t0, /* input : pitch delay given by coder */
Word16 *signal_ptr, /* input : input signal (pointer to current subframe */
Word16 *coeff, /* input : LPC coefficients for current subframe */
Word16 *sig_out, /* output: postfiltered output */
Word16 *vo, /* output: voicing decision 0 = uv, > 0 delay */
Word16 Vad /* input : frame type */
)
{
/* Local variables and arrays */
Word16 apond1[MP1]; /* s.t. denominator coeff. */
Word16 sig_ltp[L_SUBFRP1]; /* H0 output signal */
Word16 *sig_ltp_ptr;
Word16 parcor0;
/* Compute weighted LPC coefficients */
Weight_Az(coeff, GAMMA1_PST, M, apond1);
Weight_Az(coeff, GAMMA2_PST, M, apond2);
/* Compute A(gamma2) residual */
Residu(apond2, signal_ptr, res2_ptr, L_SUBFR);
/* Harmonic filtering */
sig_ltp_ptr = sig_ltp + 1;
if (sub(Vad, 1) == 0)
pst_ltp(t0, res2_ptr, sig_ltp_ptr, vo);
else {
*vo = 0;
Copy(res2_ptr, sig_ltp_ptr, L_SUBFR);
}
/* Save last output of 1/A(gamma1) */
/* (from preceding subframe) */
sig_ltp[0] = *ptr_mem_stp;
/* Controls short term pst filter gain and compute parcor0 */
calc_st_filt(apond2, apond1, &parcor0, sig_ltp_ptr);
/* 1/A(gamma1) filtering, mem_stp is updated */
Syn_filt(apond1, sig_ltp_ptr, sig_ltp_ptr, L_SUBFR, mem_stp, 1);
/* Tilt filtering */
filt_mu(sig_ltp, sig_out, parcor0);
/* Gain control */
scale_st(signal_ptr, sig_out, &gain_prec);
/**** Update for next subframe */
Copy(&res2[L_SUBFR], &res2[0], MEM_RES2);
return;
}
/*----------------------------------------------------------------------------
* Post - adaptive postfilter main function
*----------------------------------------------------------------------------
*/
void poste(
int t0, /* input : pitch delay given by coder */
FLOAT *signal_ptr, /* input : input signal (pointer to current subframe */
FLOAT *coeff, /* input : LPC coefficients for current subframe */
FLOAT *sig_out, /* output: postfiltered output */
int *vo, /* output: voicing decision 0 = uv, > 0 delay */
FLOAT gamma1, /* input: short term postfilt. den. weighting factor*/
FLOAT gamma2, /* input: short term postfilt. num. weighting factor*/
FLOAT gamma_harm, /* input: long term postfilter weighting factor*/
int long_h_st, /* input: impulse response length*/
int m_pst, /* input: LPC order */
int Vad /* input : VAD information (frame type) */
)
{
/* Local variables and arrays */
FLOAT apond1[M_BWDP1]; /* s.t. denominator coeff. */
FLOAT sig_ltp[L_SUBFRP1]; /* H0 output signal */
FLOAT *sig_ltp_ptr;
FLOAT parcor0;
/* Compute weighted LPC coefficients */
weight_az(coeff, gamma1, m_pst, apond1);
weight_az(coeff, gamma2, m_pst, apond2);
set_zero(&apond2[m_pst+1], (M_BWD-m_pst));
/* Compute A(gamma2) residual */
residue(m_pst, apond2, signal_ptr, res2_ptr, L_SUBFR);
/* Harmonic filtering */
sig_ltp_ptr = sig_ltp + 1;
if (Vad > 1)
pst_ltpe(t0, res2_ptr, sig_ltp_ptr, vo, gamma_harm);
else {
*vo = 0;
copy(res2_ptr, sig_ltp_ptr, L_SUBFR);
}
/* Save last output of 1/A(gamma1) */
/* (from preceding subframe) */
sig_ltp[0] = *ptr_mem_stp;
/* Controls short term pst filter gain and compute parcor0 */
calc_st_filte(apond2, apond1, &parcor0, sig_ltp_ptr, long_h_st, m_pst);
/* 1/A(gamma1) filtering, mem_stp is updated */
syn_filte(m_pst, apond1, sig_ltp_ptr, sig_ltp_ptr, L_SUBFR,
&mem_stp[M_BWD-m_pst], 0);
copy(&sig_ltp_ptr[L_SUBFR-M_BWD], mem_stp, M_BWD);
/* Tilt filtering */
filt_mu(sig_ltp, sig_out, parcor0);
/* Gain control */
scale_st(signal_ptr, sig_out, &gain_prec);
/**** Update for next subframe */
copy(&res2[L_SUBFR], &res2[0], MEM_RES2);
return;
}
