📄 decld8cp.c
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stat_bwd = 0;
stationnary = 0;
/* for pitch tracking in case of frame erasure */
stat_pitch = 0;
/* update the previous filter for the next frame */
Copy(&A_t_fwd[MP1], prev_filter, MP1);
for(i=MP1; i<M_BWDP1; i++) prev_filter[i] = 0;
}
else {
/***************************/
/* Processing active frame */
/***************************/
seed = INIT_SEED;
/* ---------------------------- */
/* LPC decoding in forward mode */
/* ---------------------------- */
if (lp_mode == 0) {
/* Decode the LSPs */
D_lspe(parm, lsp_new, bfi, freq_prev, prev_lsp, &prev_ma);
parm += 2;
if( prev_lp_mode == 0) { /* Interpolation of LPC for the 2 subframes */
Int_qlpc(lsp_old, lsp_new, A_t_fwd);
}
else {
/* no interpolation */
Lsp_Az(lsp_new, A_t_fwd); /* Subframe 1*/
Copy(A_t_fwd, &A_t_fwd[MP1], MP1); /* Subframe 2 */
}
/* update the LSFs for the next frame */
Copy(lsp_new, lsp_old, M);
C_int = 4506;
pA_t = A_t_fwd;
m_aq = M;
/* update the previous filter for the next frame */
Copy(&A_t_fwd[MP1], prev_filter, MP1);
for(i=MP1; i<M_BWDP1; i++) prev_filter[i] = 0;
}
else {
Int_bwd(A_t_bwd, prev_filter, &C_int);
pA_t = A_t_bwd;
m_aq = M_BWD;
/* update the previous filter for the next frame */
Copy(&A_t_bwd[M_BWDP1], prev_filter, M_BWDP1);
}
/*------------------------------------------------------------------------*
* Loop for every subframe in the analysis frame *
*------------------------------------------------------------------------*
* The subframe size is L_SUBFR and the loop is repeated L_FRAME/L_SUBFR *
* times *
* - decode the pitch delay *
* - decode algebraic code *
* - decode pitch and codebook gains *
* - find the excitation and compute synthesis speech *
*------------------------------------------------------------------------*/
for (i_subfr = 0; i_subfr < L_FRAME; i_subfr += L_SUBFR) {
index = *parm++; /* pitch index */
if(i_subfr == 0) {
if (rate == G729D)
i = 0; /* no pitch parity at 6.4 kb/s */
else
i = *parm++; /* get parity check result */
bad_pitch = add(bfi, i);
if( bad_pitch == 0) {
Dec_lag3cp(index, PIT_MIN, PIT_MAX, i_subfr, &T0, &T0_frac,rate);
prev_T0 = T0;
prev_T0_frac = T0_frac;
}
else { /* Bad frame, or parity error */
if (bfi == 0) printf(" ! Wrong Pitch 1st subfr. ! ");
T0 = prev_T0;
if (rate == G729E) {
T0_frac = prev_T0_frac;
}
else {
T0_frac = 0;
prev_T0 = add( prev_T0, 1);
if( sub(prev_T0, PIT_MAX) > 0) {
prev_T0 = PIT_MAX;
}
}
}
*T0_first = T0; /* If first frame */
}
else { /* second subframe */
if( bfi == 0) {
Dec_lag3cp(index, PIT_MIN, PIT_MAX, i_subfr, &T0, &T0_frac, rate);
prev_T0 = T0;
prev_T0_frac = T0_frac;
}
else {
T0 = prev_T0;
if (rate == G729E) {
T0_frac = prev_T0_frac;
}
else {
T0_frac = 0;
prev_T0 = add( prev_T0, 1);
if( sub(prev_T0, PIT_MAX) > 0) prev_T0 = PIT_MAX;
}
}
}
/*-------------------------------------------------*
* - Find the adaptive codebook vector. *
*-------------------------------------------------*/
Pred_lt_3(&exc[i_subfr], T0, T0_frac, L_SUBFR);
/* --------------------------------- */
/* pitch tracking for frame erasures */
/* --------------------------------- */
if( rate == G729E) {
track_pit(&prev_T0, &prev_T0_frac, &prev_pitch, &stat_pitch,
&pitch_sta, &frac_sta);
}
else {
i = prev_T0;
j = prev_T0_frac;
track_pit(&i, &j, &prev_pitch, &stat_pitch,
&pitch_sta, &frac_sta);
}
/*-------------------------------------------------------*
* - Decode innovative codebook. *
*-------------------------------------------------------*/
if(bfi != 0) { /* Bad frame */
parm[0] = Random_g729cp(&seed_fer);
parm[1] = Random_g729cp(&seed_fer);
if (rate == G729E) {
parm[2] = Random_g729cp(&seed_fer);
parm[3] = Random_g729cp(&seed_fer);
parm[4] = Random_g729cp(&seed_fer);
}
}
stationnary = 0; /* to avoid visual warning */
if (rate == G729) {
/* case 8 kbps */
Decod_ACELP(parm[1], parm[0], code);
parm += 2;
/* for gain decoding in case of frame erasure */
stat_bwd = 0;
stationnary = 0;
}
else if (rate == G729D) {
/* case 6.4 kbps */
Decod_ACELP64(parm[1], parm[0], code);
parm += 2;
/* for gain decoding in case of frame erasure */
stat_bwd = 0;
stationnary = 0;
}
else if (rate == G729E) {
/* case 11.8 kbps */
if (lp_mode == 0) {
Dec_ACELP_10i40_35bits(parm, code);
/* for gain decoding in case of frame erasure */
stat_bwd = 0;
stationnary = 0;
}
else {
Dec_ACELP_12i40_44bits(parm, code);
/* for gain decoding in case of frame erasure */
stat_bwd = add(stat_bwd,1);
if (sub(stat_bwd,30) >= 0) {
stationnary = 1;
stat_bwd = 30;
}
else stationnary = 0;
}
parm += 5;
}
/*-------------------------------------------------------*
* - Add the fixed-gain pitch contribution to code[]. *
*-------------------------------------------------------*/
j = shl(sharp, 1); /* From Q14 to Q15 */
if(sub(T0, L_SUBFR) <0 ) {
for (i = T0; i < L_SUBFR; i++) {
code[i] = add(code[i], mult(code[i-T0], j));
}
}
/*-------------------------------------------------*
* - Decode pitch and codebook gains. *
*-------------------------------------------------*/
index = *parm++; /* index of energy VQ */
if (rate == G729D)
Dec_gain_6k(index, code, L_SUBFR, bfi, &gain_pitch, &gain_code);
else
Dec_gaine(index, code, L_SUBFR, bfi, &gain_pitch, &gain_code, rate,
gain_pit_mem, gain_cod_mem, &c_muting, count_bfi, stationnary);
/*-------------------------------------------------------------*
* - Update previous gains
*-------------------------------------------------------------*/
gain_pit_mem = gain_pitch;
gain_cod_mem = gain_code;
/*-------------------------------------------------------------*
* - Update pitch sharpening "sharp" with quantized gain_pitch *
*-------------------------------------------------------------*/
sharp = gain_pitch;
if (sub(sharp, SHARPMAX) > 0) sharp = SHARPMAX;
if (sub(sharp, SHARPMIN) < 0) sharp = SHARPMIN;
/*-------------------------------------------------------*
* - Find the total excitation. *
* - Find synthesis speech corresponding to exc[]. *
*-------------------------------------------------------*/
if(bfi != 0) { /* Bad frame */
count_bfi = add(count_bfi,1);
if (voicing == 0 ) {
g_p = 0;
g_c = gain_code;
}
else {
g_p = gain_pitch;
g_c = 0;
}
}
else {
g_p = gain_pitch;
g_c = gain_code;
}
for (i = 0; i < L_SUBFR; i++) {
/* exc[i] = g_p*exc[i] + g_c*code[i]; */
/* exc[i] in Q0 g_p in Q14 */
/* code[i] in Q13 g_code in Q1 */
L_temp = L_mult(exc[i+i_subfr], g_p);
L_temp = L_mac(L_temp, code[i], g_c);
L_temp = L_shl(L_temp, 1);
exc[i+i_subfr] = round(L_temp);
}
/* Test whether synthesis yields overflow or not */
Overflow = 0;
Syn_filte(m_aq, pA_t, &exc[i_subfr], &synth[i_subfr], L_SUBFR,
&mem_syn[M_BWD-m_aq], 0);
/* In case of overflow in the synthesis */
/* -> Scale down vector exc[] and redo synthesis */
if(Overflow != 0) {
for(i=0; i<PIT_MAX+L_INTERPOL+L_FRAME; i++) old_exc[i] = shr(old_exc[i], 2);
}
if (rate == G729D) {
PhDisp(&exc[i_subfr], exc_phdisp, gain_code, gain_pitch, code);
Syn_filte(m_aq, pA_t, exc_phdisp, &synth[i_subfr], L_SUBFR,
&mem_syn[M_BWD-m_aq], 0);
}
else {
Syn_filte(m_aq, pA_t, &exc[i_subfr], &synth[i_subfr], L_SUBFR,
&mem_syn[M_BWD-m_aq], 0);
/* Updates state machine for phase dispersion in
6.4 kbps mode, if running at other rate */
Update_PhDisp(gain_pitch, gain_code);
}
pA_t += m_aq+1; /* interpolated LPC parameters for next subframe */
Copy(&synth[i_subfr+L_SUBFR-M_BWD], mem_syn, M_BWD);
}
}
/*------------*
* For G729b
*-----------*/
if(bfi == 0) {
L_temp = 0L;
for(i=0; i<L_FRAME; i++) {
L_temp = L_mac(L_temp, exc[i], exc[i]);
} /* may overflow => last level of SID quantizer */
sh_sid_sav = norm_l(L_temp);
sid_sav = round(L_shl(L_temp, sh_sid_sav));
sh_sid_sav = sub(16, sh_sid_sav);
}
past_ftyp = ftyp;
/*------------*
* For G729E
*-----------*/
energy = ener_dB(synth, L_FRAME);
if (energy >= 8192) tst_bwd_dominant(bwd_dominant, lp_mode);
/*--------------------------------------------------*
* Update signal for next frame. *
* -> shift to the left by L_FRAME exc[] *
*--------------------------------------------------*/
Copy(&old_exc[L_FRAME], &old_exc[0], PIT_MAX+L_INTERPOL);
if( lp_mode == 0) {
Copy(A_t_fwd, Az_dec, 2*MP1);
*m_pst = M;
}
else {
Copy(A_t_bwd, Az_dec, 2*M_BWDP1);
*m_pst = M_BWD;
}
prev_bfi = bfi;
prev_lp_mode = lp_mode;
prev_voicing = voicing;
if (bfi != 0) C_fe_fix = 4096;
else {
if (lp_mode == 0) C_fe_fix = 0;
else {
if (*bwd_dominant == 1) C_fe_fix = sub(C_fe_fix, 410);
else C_fe_fix = sub(C_fe_fix, 2048);
if (C_fe_fix < 0) C_fe_fix= 0;
}
}
return;
}
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