/*--------------------------------------------------------------------------
* init_decod_ld8k - Initialization of variables for the decoder section.
*--------------------------------------------------------------------------
*/
public void init_decod_ld8k() {
/* Initialize static pointer */
exc = 0 + LD8KConstants.PIT_MAX + LD8KConstants.L_INTERPOL;
/* Static vectors to zero */
Util.set_zero(old_exc_array, LD8KConstants.PIT_MAX + LD8KConstants.L_INTERPOL);
Util.set_zero(mem_syn, LD8KConstants.M);
sharp = LD8KConstants.SHARPMIN;
old_t0 = 60;
gain_code.value = (float) 0.;
gain_pitch.value = (float) 0.;
lspDec.lsp_decw_reset();
return;
}
/*--------------------------------------------------------------------------
* decod_ld8k - decoder
*--------------------------------------------------------------------------
*/
public void decod_ld8k(
int parm[],
int parms, /*
* input : synthesis parameters (parm[0] = bfi)
*/
int voicing, /* input : voicing decision from previous frame */
float synth[],
int ss, /* output: synthesized speech */
float A_t[], /* output: two sets of A(z) coefficients length=2*MP1 */
IntegerPointer t0_first /* output: integer delay of first subframe */) {
int Az; /* Pointer to A_t (LPC coefficients) */
float lsp_new[] = new float[LD8KConstants.M]; /* LSPs */
float code[] = new float[LD8KConstants.L_SUBFR]; /* algebraic codevector */
/* Scalars */
int i, i_subfr;
int index;
IntegerPointer t0 = new IntegerPointer(), t0_frac = new IntegerPointer();
int bfi;
int bad_pitch;
/* Test bad frame indicator (bfi) */
bfi = parm[parms++];
/* Decode the LSPs */
lspDec.d_lsp(parm, parms, lsp_new, bfi);
parms += 2; /* Advance synthesis parameters pointer */
/* Interpolation of LPC for the 2 subframes */
LpcFunc.int_qlpc(lsp_old, lsp_new, A_t);
/* update the LSFs for the next frame */
Util.copy(lsp_new, lsp_old, LD8KConstants.M);
/*------------------------------------------------------------------------*
* 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 *
*------------------------------------------------------------------------*/
Az = 0; // A_t; /* pointer to interpolated LPC parameters */
for (i_subfr = 0; i_subfr < LD8KConstants.L_FRAME; i_subfr += LD8KConstants.L_SUBFR) {
index = parm[parms++]; /* pitch index */
if (i_subfr == 0) {
/* if first subframe */
i = parm[parms++]; /* get parity check result */
bad_pitch = bfi + i;
if (bad_pitch == 0) {
DecLag.dec_lag3(
index, LD8KConstants.PIT_MIN, LD8KConstants.PIT_MAX, i_subfr, t0, t0_frac);
old_t0 = t0.value;
} else /* Bad frame, or parity error */ {
t0.value = old_t0;
t0_frac.value = 0;
old_t0++;
if (old_t0 > LD8KConstants.PIT_MAX) {
old_t0 = LD8KConstants.PIT_MAX;
}
}
t0_first.value = t0.value; /* If first frame */
} else /* second subframe */ {
if (bfi == 0) {
DecLag.dec_lag3(
index, LD8KConstants.PIT_MIN, LD8KConstants.PIT_MAX, i_subfr, t0, t0_frac);
old_t0 = t0.value;
} else {
t0.value = old_t0;
t0_frac.value = 0;
old_t0++;
if (old_t0 > LD8KConstants.PIT_MAX) {
old_t0 = LD8KConstants.PIT_MAX;
}
}
}
/*-------------------------------------------------*
* - Find the adaptive codebook vector. *
*--------------------------------------------------*/
PredLt.pred_lt_3(
old_exc_array, exc + i_subfr, t0.value, t0_frac.value, LD8KConstants.L_SUBFR);
/*-------------------------------------------------------*
* - Decode innovative codebook. *
* - Add the fixed-gain pitch contribution to code[]. *
*-------------------------------------------------------*/
if (bfi != 0) {
/* Bad Frame Error Concealment */
parm[parms + 0] = (int) (Util.random_g729() & 0x1fff); /*
* 13 bits random
*/
parm[parms + 1] = (int) (Util.random_g729() & 0x000f); /*
* 4 bits random
*/
}
DecAcelp.decod_ACELP(parm[parms + 1], parm[parms + 0], code);
parms += 2;
for (i = t0.value; i < LD8KConstants.L_SUBFR; i++) code[i] += sharp * code[i - t0.value];
/*-------------------------------------------------*
* - Decode pitch and codebook gains. *
*-------------------------------------------------*/
index = parm[parms++]; /* index of energy VQ */
decGain.dec_gain(index, code, LD8KConstants.L_SUBFR, bfi, gain_pitch, gain_code);
/*-------------------------------------------------------------*
* - Update pitch sharpening "sharp" with quantized gain_pitch *
*-------------------------------------------------------------*/
sharp = gain_pitch.value;
if (sharp > LD8KConstants.SHARPMAX) sharp = LD8KConstants.SHARPMAX;
if (sharp < LD8KConstants.SHARPMIN) sharp = LD8KConstants.SHARPMIN;
/*-------------------------------------------------------*
* - Find the total excitation. *
*-------------------------------------------------------*/
if (bfi != 0) {
if (voicing == 0) {
/* for unvoiced frame */
for (i = 0; i < LD8KConstants.L_SUBFR; i++) {
old_exc_array[exc + i + i_subfr] = gain_code.value * code[i];
}
} else {
/* for voiced frame */
for (i = 0; i < LD8KConstants.L_SUBFR; i++) {
old_exc_array[exc + i + i_subfr] = gain_pitch.value * old_exc_array[exc + i + i_subfr];
}
}
} else {
/* No frame errors */
for (i = 0; i < LD8KConstants.L_SUBFR; i++) {
old_exc_array[exc + i + i_subfr] =
gain_pitch.value * old_exc_array[exc + i + i_subfr] + gain_code.value * code[i];
}
}
/*-------------------------------------------------------*
* - Find synthesis speech corresponding to exc[]. *
*-------------------------------------------------------*/
Filter.syn_filt(
A_t,
Az,
old_exc_array,
exc + i_subfr,
synth,
ss + i_subfr,
LD8KConstants.L_SUBFR,
mem_syn,
0,
1);
Az += LD8KConstants.MP1; /*
* interpolated LPC parameters for next subframe
*/
}
/*--------------------------------------------------*
* Update signal for next frame. *
* -> shift to the left by L_FRAME exc[] *
*--------------------------------------------------*/
Util.copy(
old_exc_array,
LD8KConstants.L_FRAME,
old_exc_array,
0,
LD8KConstants.PIT_MAX + LD8KConstants.L_INTERPOL);
return;
}
