void sid_lsfq_decode(
int *index, /* (i) : quantized indices */
FLOAT *lspq, /* (o) : quantized lsp vector */
FLOAT freq_prev[MA_NP][M] /* (i) : memory of predictor */
)
{
int i;
FLOAT lsfq[M], tmpbuf[M];
/* get the lsf error vector */
copy(lspcb1[PtrTab_1[index[1]]], tmpbuf, M);
for (i=0; i<M/2; i++)
tmpbuf[i] = tmpbuf[i]+ lspcb2[PtrTab_2[0][index[2]]][i];
for (i=M/2; i<M; i++)
tmpbuf[i] = tmpbuf[i]+ lspcb2[PtrTab_2[1][index[2]]][i];
/* guarantee minimum distance of 0.0012 between tmpbuf[j]
and tmpbuf[j+1] */
lsp_expand_1_2(tmpbuf, (FLOAT)0.0012);
/* compute the quantized lsf vector */
lsp_prev_compose(tmpbuf, lsfq, noise_fg[index[0]], freq_prev,
noise_fg_sum[index[0]]);
/* update the prediction memory */
lsp_prev_update(tmpbuf, freq_prev);
/* lsf stability check */
lsp_stability(lsfq);
/* convert lsf to lsp */
for (i=0; i<M; i++ )
lspq[i] = (FLOAT)cos(lsfq[i]);
}
/*-----------------------------------------------------------------*
* Functions lsfq_noise *
* ~~~~~~~~~~ *
* Input: *
* lsp[] : unquantized lsp vector *
* freq_prev[][] : memory of the lsf predictor *
* *
* Output: *
* *
* lspq[] : quantized lsp vector *
* ana[] : indices *
* *
*-----------------------------------------------------------------*/
void lsfq_noise(float * lsp, float * lspq, float freq_prev[MA_NP][M], int *ana)
{
int i, MS[MODE] = { 32, 16 }, Clust[MODE], mode;
float lsf[M], lsfq[M], weight[M], tmpbuf[M], errlsf[M * MODE];
/* convert lsp to lsf */
for (i = 0; i < M; i++)
lsf[i] = (float) acos(lsp[i]);
/* spacing to ~100Hz */
if (lsf[0] < L_LIMIT)
lsf[0] = L_LIMIT;
for (i = 0; i < M - 1; i++) {
if (lsf[i + 1] - lsf[i] < 2 * GAP3)
lsf[i + 1] = lsf[i] + 2 * GAP3;
}
if (lsf[M - 1] > M_LIMIT)
lsf[M - 1] = M_LIMIT;
if (lsf[M - 1] < lsf[M - 2])
lsf[M - 2] = lsf[M - 1] - GAP3;
/* get the lsf weighting */
get_wegt(lsf, weight);
/**********************/
/* quantize the lsf's */
/**********************/
/* get the prediction error vector */
for (mode = 0; mode < MODE; mode++)
lsp_prev_extract(lsf, errlsf + mode * M, noise_fg[mode],
freq_prev, noise_fg_sum_inv[mode]);
/* quantize the lsf and get the corresponding indices */
Qnt_e(errlsf, weight, MODE, tmpbuf, &mode, 1, Clust, MS);
ana[0] = (int)mode;
ana[1] = (int)Clust[0];
ana[2] = (int)Clust[1];
/* guarantee minimum distance of 0.0012 between tmpbuf[j]
and tmpbuf[j+1] */
lsp_expand_1_2(tmpbuf, (float) 0.0012);
/* compute the quantized lsf vector */
lsp_prev_compose(tmpbuf, lsfq, noise_fg[mode], freq_prev,
noise_fg_sum[mode]);
/* update the prediction memory */
lsp_prev_update(tmpbuf, freq_prev);
/* lsf stability check */
lsp_stability(lsfq);
/* convert lsf to lsp */
for (i = 0; i < M; i++)
lspq[i] = (float) cos(lsfq[i]);
return;
}
