/*-----------------------------------------------------------*
* procedure Cod_cng: *
* ~~~~~~~~ *
* computes DTX decision *
* encodes SID frames *
* computes CNG excitation for encoder update *
*-----------------------------------------------------------*/
void Cod_cng(
DtxStatus *handle,
Word16 *exc, /* (i/o) : excitation array */
Word16 pastVad, /* (i) : previous VAD decision */
Word16 *lsp_old_q, /* (i/o) : previous quantized lsp */
Word16 *Aq, /* (o) : set of interpolated LPC coefficients */
Word16 *ana, /* (o) : coded SID parameters */
Word16 freq_prev[MA_NP][M],
/* (i/o) : previous LPS for quantization */
Word16 *seed /* (i/o) : random generator seed */
)
{
Word16 i;
Word16 curAcf[MP1];
Word16 bid[M], zero[MP1];
Word16 curCoeff[MP1];
Word16 lsp_new[M];
Word16 *lpcCoeff;
Word16 cur_igain;
Word16 energyq, temp;
/* Update Ener and sh_ener */
for(i = NB_GAIN-1; i>=1; i--) {
handle->ener[i] = handle->ener[i-1];
handle->sh_ener[i] = handle->sh_ener[i-1];
}
/* Compute current Acfs */
Calc_sum_acf(handle->Acf, handle->sh_Acf, curAcf, &(handle->sh_ener[0]), NB_CURACF);
/* Compute LPC coefficients and residual energy */
if(curAcf[0] == 0) {
handle->ener[0] = 0; /* should not happen */
}
else {
Set_zero(zero, MP1);
Levinson(handle, curAcf, zero, curCoeff, bid, &(handle->ener[0]));
}
/* if first frame of silence => SID frame */
if(pastVad != 0) {
ana[0] = 2;
handle->count_fr0 = 0;
handle->nb_ener = 1;
Qua_Sidgain(handle->ener, handle->sh_ener, handle->nb_ener, &energyq, &cur_igain);
}
else {
handle->nb_ener = add(handle->nb_ener, 1);
if(sub(handle->nb_ener, NB_GAIN) > 0) handle->nb_ener = NB_GAIN;
Qua_Sidgain(handle->ener, handle->sh_ener, handle->nb_ener, &energyq, &cur_igain);
/* Compute stationarity of current filter */
/* versus reference filter */
if(Cmp_filt(handle->RCoeff, handle->sh_RCoeff, curAcf, handle->ener[0], FRAC_THRESH1) != 0) {
handle->flag_chang = 1;
}
/* compare energy difference between current frame and last frame */
temp = abs_s(sub(handle->prev_energy, energyq));
temp = sub(temp, 2);
if (temp > 0) handle->flag_chang = 1;
handle->count_fr0 = add(handle->count_fr0, 1);
if(sub(handle->count_fr0, FR_SID_MIN) < 0) {
ana[0] = 0; /* no transmission */
}
else {
if(handle->flag_chang != 0) {
ana[0] = 2; /* transmit SID frame */
}
else{
ana[0] = 0;
}
handle->count_fr0 = FR_SID_MIN; /* to avoid overflow */
}
}
if(sub(ana[0], 2) == 0) {
/* Reset frame count and change flag */
handle->count_fr0 = 0;
handle->flag_chang = 0;
/* Compute past average filter */
Calc_pastfilt(handle, handle->pastCoeff);
Calc_RCoeff(handle->pastCoeff, handle->RCoeff, &(handle->sh_RCoeff));
/* Compute stationarity of current filter */
/* versus past average filter */
/* if stationary */
/* transmit average filter => new ref. filter */
if(Cmp_filt(handle->RCoeff, handle->sh_RCoeff, curAcf, handle->ener[0], FRAC_THRESH2) == 0) {
lpcCoeff = handle->pastCoeff;
}
/* else */
/* transmit current filter => new ref. filter */
else {
lpcCoeff = curCoeff;
Calc_RCoeff(curCoeff, handle->RCoeff, &(handle->sh_RCoeff));
}
/* Compute SID frame codes */
Az_lsp(lpcCoeff, lsp_new, lsp_old_q); /* From A(z) to lsp */
/* LSP quantization */
lsfq_noise(lsp_new, handle->lspSid_q, freq_prev, &ana[1]);
handle->prev_energy = energyq;
ana[4] = cur_igain;
handle->sid_gain = tab_Sidgain[cur_igain];
} /* end of SID frame case */
/* Compute new excitation */
if(pastVad != 0) {
handle->cur_gain = handle->sid_gain;
}
else {
handle->cur_gain = mult_r(handle->cur_gain, A_GAIN0);
handle->cur_gain = add(handle->cur_gain, mult_r(handle->sid_gain, A_GAIN1));
}
Calc_exc_rand(handle->L_exc_err, handle->cur_gain, exc, seed, FLAG_COD);
Int_qlpc(lsp_old_q, handle->lspSid_q, Aq);
for(i=0; i<M; i++) {
lsp_old_q[i] = handle->lspSid_q[i];
}
/* Update sumAcf if fr_cur = 0 */
if(handle->fr_cur == 0) {
Update_sumAcf(handle);
}
return;
}
/*-----------------------------------------------------------*
* procedure cod_cng: *
* ~~~~~~~~ *
* computes DTX decision *
* encodes SID frames *
* computes CNG excitation for encoder update *
*-----------------------------------------------------------*/
void cod_cng(float * exc, /* (i/o) : excitation array */
int pastVad, /* (i) : previous VAD decision */
float * lsp_old_q, /* (i/o) : previous quantized lsp */
float * old_A, /* (i/o) : last stable filter LPC coefficients */
float * old_rc, /* (i/o) : last stable filter Reflection coefficients. */
float * Aq, /* (o) : set of interpolated LPC coefficients */
int *ana, /* (o) : coded SID parameters */
float freq_prev[MA_NP][M], /* (i/o) : previous LPS for quantization */
int16_t * seed /* (i/o) : random generator seed */
)
{
int i;
float curAcf[MP1];
float bid[MP1];
float curCoeff[MP1];
float lsp_new[M];
float *lpcCoeff;
int cur_igain;
float energyq;
/* Update Ener */
for (i = NB_GAIN - 1; i >= 1; i--) {
ener[i] = ener[i - 1];
}
/* Compute current Acfs */
calc_sum_acf(Acf, curAcf, NB_CURACF);
/* Compute LPC coefficients and residual energy */
if (curAcf[0] == (float) 0.) {
ener[0] = (float) 0.; /* should not happen */
} else {
ener[0] = levinsone(M, curAcf, curCoeff, bid, old_A, old_rc);
}
/* if first frame of silence => SID frame */
if (pastVad != 0) {
ana[0] = 1;
count_fr0 = 0;
nb_ener = 1;
qua_Sidgain(ener, nb_ener, &energyq, &cur_igain);
} else {
nb_ener++;
if (nb_ener > NB_GAIN)
nb_ener = NB_GAIN;
qua_Sidgain(ener, nb_ener, &energyq, &cur_igain);
/* Compute stationarity of current filter */
/* versus reference filter */
if (cmp_filt(RCoeff, curAcf, ener[0], THRESH1) != 0) {
flag_chang = 1;
}
/* compare energy difference between current frame and last frame */
if ((float) fabs(prev_energy - energyq) > (float) 2.0)
flag_chang = 1;
count_fr0++;
if (count_fr0 < FR_SID_MIN) {
ana[0] = 0; /* no transmission */
} else {
if (flag_chang != 0) {
ana[0] = 1; /* transmit SID frame */
} else {
ana[0] = 0;
}
count_fr0 = FR_SID_MIN; /* to avoid overflow */
}
}
if (ana[0] == 1) {
/* Reset frame count and change flag */
count_fr0 = 0;
flag_chang = 0;
/* Compute past average filter */
calc_pastfilt(pastCoeff, old_A, old_rc);
calc_RCoeff(pastCoeff, RCoeff);
/* Compute stationarity of current filter */
/* versus past average filter */
/* if stationary */
/* transmit average filter => new ref. filter */
if (cmp_filt(RCoeff, curAcf, ener[0], THRESH2) == 0) {
lpcCoeff = pastCoeff;
}
/* else */
/* transmit current filter => new ref. filter */
else {
lpcCoeff = curCoeff;
calc_RCoeff(curCoeff, RCoeff);
}
/* Compute SID frame codes */
az_lsp(lpcCoeff, lsp_new, lsp_old_q); /* From A(z) to lsp */
/* LSP quantization */
lsfq_noise(lsp_new, lspSid_q, freq_prev, &ana[1]);
prev_energy = energyq;
ana[4] = cur_igain;
sid_gain = tab_Sidgain[cur_igain];
}
/* end of SID frame case */
/* Compute new excitation */
if (pastVad != 0) {
cur_gain = sid_gain;
} else {
cur_gain *= A_GAIN0;
cur_gain += A_GAIN1 * sid_gain;
}
calc_exc_rand(cur_gain, exc, seed, FLAG_COD);
int_qlpc(lsp_old_q, lspSid_q, Aq);
for (i = 0; i < M; i++) {
lsp_old_q[i] = lspSid_q[i];
}
/* Update sumAcf if fr_cur = 0 */
if (fr_cur == 0) {
update_sumAcf();
}
return;
}
