?? acelp_co.c
字號(hào):
/* Version 3.3 Last modified: December 26, 1995 */
/*---------------------------------------------------------------------------*
* Function ACELP_CODEBOOK() *
* ~~~~~~~~~~~~~~~~~~~~~~~~~~ *
* Find Algebraic codebook. *
*--------------------------------------------------------------------------*/
#include "typedef.h"
#include "basic_op.h"
#include "ld8k.h"
static void Cor_h(
Word16 *H, /* (i) Q12 :Impulse response of filters */
Word16 *rr /* (o) :Correlations of H[] */
);
static void Cor_h_X(
Word16 h[], /* (i) Q12 :Impulse response of filters */
Word16 X[], /* (i) Q12 :Target vector */
Word16 D[] /* (o) :Correlations between h[] and D[] */
/* Normalized to 13 bits */
);
static Word16 D4i40_17( /* (o) : Index of pulses positions. */
Word16 Dn[], /* (i) : Correlations between h[] and Xn[]. */
Word16 rr[], /* (i) : Correlations of impulse response h[]. */
Word16 h[], /* (i) Q12: Impulse response of filters. */
Word16 cod[], /* (o) Q13: Selected algebraic codeword. */
Word16 y[], /* (o) Q12: Filtered algebraic codeword. */
Word16 *sign, /* (o) : Signs of 4 pulses. */
Word16 i_subfr /* (i) : subframe flag */
);
Word16 ACELP_Codebook( /* (o) :index of pulses positions */
Word16 x[], /* (i) :Target vector */
Word16 h[], /* (i) Q12 :Impulse response of filters */
Word16 T0, /* (i) :Pitch lag */
Word16 pitch_sharp, /* (i) Q14 :Last quantized pitch gain */
Word16 i_subfr, /* (i) :Indicator of 1st subframe, */
Word16 code[], /* (o) Q13 :Innovative codebook */
Word16 y[], /* (o) Q12 :Filtered innovative codebook */
Word16 *sign /* (o) :Signs of 4 pulses */
)
{
Word16 i, index, sharp;
Word16 Dn[L_SUBFR];
Word16 rr[DIM_RR];
/*-----------------------------------------------------------------*
* Include fixed-gain pitch contribution into impulse resp. h[] *
* Find correlations of h[] needed for the codebook search. *
*-----------------------------------------------------------------*/
sharp = shl(pitch_sharp, 1); /* From Q14 to Q15 */
if (sub(T0, L_SUBFR)<0)
for (i = T0; i < L_SUBFR; i++){ /* h[i] += pitch_sharp*h[i-T0] */
h[i] = add(h[i], mult(h[i-T0], sharp));
}
Cor_h(h, rr);
/*-----------------------------------------------------------------*
* Compute correlation of target vector with impulse response. *
*-----------------------------------------------------------------*/
Cor_h_X(h, x, Dn);
/*-----------------------------------------------------------------*
* Find innovative codebook. *
*-----------------------------------------------------------------*/
index = D4i40_17(Dn, rr, h, code, y, sign, i_subfr);
/*-----------------------------------------------------------------*
* Compute innovation vector gain. *
* Include fixed-gain pitch contribution into code[]. *
*-----------------------------------------------------------------*/
if(sub(T0 ,L_SUBFR) <0)
for (i = T0; i < L_SUBFR; i++) { /* code[i] += pitch_sharp*code[i-T0] */
code[i] = add(code[i], mult(code[i-T0], sharp));
}
return index;
}
/*--------------------------------------------------------------------------*
* Function Corr_h_X() *
* ~~~~~~~~~~~~~~~~~~~~ *
* Compute correlations of input response h[] with the target vector X[]. *
*--------------------------------------------------------------------------*/
static void Cor_h_X(
Word16 h[], /* (i) Q12 :Impulse response of filters */
Word16 X[], /* (i) :Target vector */
Word16 D[] /* (o) :Correlations between h[] and D[] */
/* Normalized to 13 bits */
)
{
Word16 i, j;
Word32 s, max, L_temp;
Word32 y32[L_SUBFR];
/* first keep the result on 32 bits and find absolute maximum */
max = 0;
for (i = 0; i < L_SUBFR; i++)
{
s = 0;
for (j = i; j < L_SUBFR; j++)
s = L_mac(s, X[j], h[j-i]);
y32[i] = s;
s = L_abs(s);
L_temp =L_sub(s,max);
if(L_temp>0L) {
max = s;
}
}
/* Find the number of right shifts to do on y32[] */
/* so that maximum is on 13 bits */
j = norm_l(max);
if( sub(j,16) > 0) {
j = 16;
}
j = sub(18, j);
for(i=0; i<L_SUBFR; i++) {
D[i] = extract_l( L_shr(y32[i], j) );
}
return;
}
/*--------------------------------------------------------------------------*
* Function Cor_h() *
* ~~~~~~~~~~~~~~~~~ *
* Compute correlations of h[] needed for the codebook search. *
*--------------------------------------------------------------------------*/
static void Cor_h(
Word16 *H, /* (i) Q12 :Impulse response of filters */
Word16 *rr /* (o) :Correlations of H[] */
)
{
Word16 *rri0i0, *rri1i1, *rri2i2, *rri3i3, *rri4i4;
Word16 *rri0i1, *rri0i2, *rri0i3, *rri0i4;
Word16 *rri1i2, *rri1i3, *rri1i4;
Word16 *rri2i3, *rri2i4;
Word16 *p0, *p1, *p2, *p3, *p4;
Word16 *ptr_hd, *ptr_hf, *ptr_h1, *ptr_h2;
Word32 cor;
Word16 i, k, ldec, l_fin_sup, l_fin_inf;
Word16 h[L_SUBFR];
Word32 L_tmp;
/* Scaling h[] for maximum precision */
cor = 0;
for(i=0; i<L_SUBFR; i++)
cor = L_mac(cor, H[i], H[i]);
L_tmp = L_sub(extract_h(cor),32000);
if(L_tmp>0L )
{
for(i=0; i<L_SUBFR; i++) {
h[i] = shr(H[i], 1);}
}
else
{
k = norm_l(cor);
k = shr(k, 1);
for(i=0; i<L_SUBFR; i++) {
h[i] = shl(H[i], k); }
}
/* Init pointers */
rri0i0 = rr;
rri1i1 = rri0i0 + NB_POS;
rri2i2 = rri1i1 + NB_POS;
rri3i3 = rri2i2 + NB_POS;
rri4i4 = rri3i3 + NB_POS;
rri0i1 = rri4i4 + NB_POS;
rri0i2 = rri0i1 + MSIZE;
rri0i3 = rri0i2 + MSIZE;
rri0i4 = rri0i3 + MSIZE;
rri1i2 = rri0i4 + MSIZE;
rri1i3 = rri1i2 + MSIZE;
rri1i4 = rri1i3 + MSIZE;
rri2i3 = rri1i4 + MSIZE;
rri2i4 = rri2i3 + MSIZE;
/*------------------------------------------------------------*
* Compute rri0i0[], rri1i1[], rri2i2[], rri3i3 and rri4i4[] *
*------------------------------------------------------------*/
p0 = rri0i0 + NB_POS-1; /* Init pointers to last position of rrixix[] */
p1 = rri1i1 + NB_POS-1;
p2 = rri2i2 + NB_POS-1;
p3 = rri3i3 + NB_POS-1;
p4 = rri4i4 + NB_POS-1;
ptr_h1 = h;
cor = 0;
for(i=0; i<NB_POS; i++)
{
cor = L_mac(cor, *ptr_h1, *ptr_h1); ptr_h1++;
*p4-- = extract_h(cor);
cor = L_mac(cor, *ptr_h1, *ptr_h1); ptr_h1++;
*p3-- = extract_h(cor);
cor = L_mac(cor, *ptr_h1, *ptr_h1); ptr_h1++;
*p2-- = extract_h(cor);
cor = L_mac(cor, *ptr_h1, *ptr_h1); ptr_h1++;
*p1-- = extract_h(cor);
cor = L_mac(cor, *ptr_h1, *ptr_h1); ptr_h1++;
*p0-- = extract_h(cor);
}
/*-----------------------------------------------------------------*
* Compute elements of: rri2i3[], rri1i2[], rri0i1[] and rri0i4[] *
*-----------------------------------------------------------------*/
l_fin_sup = MSIZE-1;
l_fin_inf = l_fin_sup-(Word16)1;
ldec = NB_POS+1;
ptr_hd = h;
ptr_hf = ptr_hd + 1;
for(k=0; k<NB_POS; k++) {
p3 = rri2i3 + l_fin_sup;
p2 = rri1i2 + l_fin_sup;
p1 = rri0i1 + l_fin_sup;
p0 = rri0i4 + l_fin_inf;
cor = 0;
ptr_h1 = ptr_hd;
ptr_h2 = ptr_hf;
for(i=k+(Word16)1; i<NB_POS; i++ ) {
cor = L_mac(cor, *ptr_h1, *ptr_h2); ptr_h1++; ptr_h2++;
cor = L_mac(cor, *ptr_h1, *ptr_h2); ptr_h1++; ptr_h2++;
*p3 = extract_h(cor);
cor = L_mac(cor, *ptr_h1, *ptr_h2); ptr_h1++; ptr_h2++;
*p2 = extract_h(cor);
cor = L_mac(cor, *ptr_h1, *ptr_h2); ptr_h1++; ptr_h2++;
*p1 = extract_h(cor);
cor = L_mac(cor, *ptr_h1, *ptr_h2); ptr_h1++; ptr_h2++;
*p0 = extract_h(cor);
p3 -= ldec;
p2 -= ldec;
p1 -= ldec;
p0 -= ldec;
}
cor = L_mac(cor, *ptr_h1, *ptr_h2); ptr_h1++; ptr_h2++;
cor = L_mac(cor, *ptr_h1, *ptr_h2); ptr_h1++; ptr_h2++;
*p3 = extract_h(cor);
cor = L_mac(cor, *ptr_h1, *ptr_h2); ptr_h1++; ptr_h2++;
*p2 = extract_h(cor);
cor = L_mac(cor, *ptr_h1, *ptr_h2); ptr_h1++; ptr_h2++;
*p1 = extract_h(cor);
l_fin_sup -= NB_POS;
l_fin_inf--;
ptr_hf += STEP;
}
/*---------------------------------------------------------------------*
* Compute elements of: rri2i4[], rri1i3[], rri0i2[], rri1i4[], rri0i3 *
*---------------------------------------------------------------------*/
ptr_hd = h;
ptr_hf = ptr_hd + 2;
l_fin_sup = MSIZE-1;
l_fin_inf = l_fin_sup-(Word16)1;
for(k=0; k<NB_POS; k++) {
p4 = rri2i4 + l_fin_sup;
p3 = rri1i3 + l_fin_sup;
p2 = rri0i2 + l_fin_sup;
p1 = rri1i4 + l_fin_inf;
p0 = rri0i3 + l_fin_inf;
cor = 0;
ptr_h1 = ptr_hd;
ptr_h2 = ptr_hf;
for(i=k+(Word16)1; i<NB_POS; i++ ) {
cor = L_mac(cor, *ptr_h1, *ptr_h2); ptr_h1++; ptr_h2++;
*p4 = extract_h(cor);
cor = L_mac(cor, *ptr_h1, *ptr_h2); ptr_h1++; ptr_h2++;
*p3 = extract_h(cor);
cor = L_mac(cor, *ptr_h1, *ptr_h2); ptr_h1++; ptr_h2++;
*p2 = extract_h(cor);
cor = L_mac(cor, *ptr_h1, *ptr_h2); ptr_h1++; ptr_h2++;
*p1 = extract_h(cor);
cor = L_mac(cor, *ptr_h1, *ptr_h2); ptr_h1++; ptr_h2++;
*p0 = extract_h(cor);
p4 -= ldec;
p3 -= ldec;
p2 -= ldec;
p1 -= ldec;
p0 -= ldec;
}
cor = L_mac(cor, *ptr_h1, *ptr_h2); ptr_h1++; ptr_h2++;
*p4 = extract_h(cor);
cor = L_mac(cor, *ptr_h1, *ptr_h2); ptr_h1++; ptr_h2++;
*p3 = extract_h(cor);
cor = L_mac(cor, *ptr_h1, *ptr_h2); ptr_h1++; ptr_h2++;
*p2 = extract_h(cor);
l_fin_sup -= NB_POS;
l_fin_inf--;
ptr_hf += STEP;
}
/*----------------------------------------------------------------------*
* Compute elements of: rri1i4[], rri0i3[], rri2i4[], rri1i3[], rri0i2 *
*----------------------------------------------------------------------*/
ptr_hd = h;
ptr_hf = ptr_hd + 3;
l_fin_sup = MSIZE-1;
l_fin_inf = l_fin_sup-(Word16)1;
for(k=0; k<NB_POS; k++) {
p4 = rri1i4 + l_fin_sup;
p3 = rri0i3 + l_fin_sup;
p2 = rri2i4 + l_fin_inf;
p1 = rri1i3 + l_fin_inf;
p0 = rri0i2 + l_fin_inf;
ptr_h1 = ptr_hd;
ptr_h2 = ptr_hf;
cor = 0;
for(i=k+(Word16)1; i<NB_POS; i++ ) {
cor = L_mac(cor, *ptr_h1, *ptr_h2); ptr_h1++; ptr_h2++;
*p4 = extract_h(cor);
cor = L_mac(cor, *ptr_h1, *ptr_h2); ptr_h1++; ptr_h2++;
*p3 = extract_h(cor);
cor = L_mac(cor, *ptr_h1, *ptr_h2); ptr_h1++; ptr_h2++;
*p2 = extract_h(cor);
cor = L_mac(cor, *ptr_h1, *ptr_h2); ptr_h1++; ptr_h2++;
*p1 = extract_h(cor);
cor = L_mac(cor, *ptr_h1, *ptr_h2); ptr_h1++; ptr_h2++;
*p0 = extract_h(cor);
p4 -= ldec;
p3 -= ldec;
p2 -= ldec;
p1 -= ldec;
p0 -= ldec;
}
cor = L_mac(cor, *ptr_h1, *ptr_h2); ptr_h1++; ptr_h2++;
*p4 = extract_h(cor);
cor = L_mac(cor, *ptr_h1, *ptr_h2); ptr_h1++; ptr_h2++;
*p3 = extract_h(cor);
l_fin_sup -= NB_POS;
l_fin_inf--;
ptr_hf += STEP;
}
/*----------------------------------------------------------------------*
* Compute elements of: rri0i4[], rri2i3[], rri1i2[], rri0i1[] *
*----------------------------------------------------------------------*/
ptr_hd = h;
ptr_hf = ptr_hd + 4;
l_fin_sup = MSIZE-1;
l_fin_inf = l_fin_sup-(Word16)1;
for(k=0; k<NB_POS; k++) {
p3 = rri0i4 + l_fin_sup;
p2 = rri2i3 + l_fin_inf;
p1 = rri1i2 + l_fin_inf;
p0 = rri0i1 + l_fin_inf;
ptr_h1 = ptr_hd;
ptr_h2 = ptr_hf;
cor = 0;
for(i=k+(Word16)1; i<NB_POS; i++ ) {
cor = L_mac(cor, *ptr_h1, *ptr_h2); ptr_h1++; ptr_h2++;
*p3 = extract_h(cor);
cor = L_mac(cor, *ptr_h1, *ptr_h2); ptr_h1++; ptr_h2++;
cor = L_mac(cor, *ptr_h1, *ptr_h2); ptr_h1++; ptr_h2++;
*p2 = extract_h(cor);
cor = L_mac(cor, *ptr_h1, *ptr_h2); ptr_h1++; ptr_h2++;
*p1 = extract_h(cor);
cor = L_mac(cor, *ptr_h1, *ptr_h2); ptr_h1++; ptr_h2++;
*p0 = extract_h(cor);
p3 -= ldec;
p2 -= ldec;
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