?? exc_lbc.c
字號:
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;
ptr_h1 = h;
cor = 0;
for(i=0; i<NB_POS; i++) {
cor = L_mac(cor, *ptr_h1, *ptr_h1); ptr_h1++;
cor = L_mac(cor, *ptr_h1, *ptr_h1); ptr_h1++;
*p3-- = extract_h(cor);
cor = L_mac(cor, *ptr_h1, *ptr_h1); ptr_h1++;
cor = L_mac(cor, *ptr_h1, *ptr_h1); ptr_h1++;
*p2-- = extract_h(cor);
cor = L_mac(cor, *ptr_h1, *ptr_h1); ptr_h1++;
cor = L_mac(cor, *ptr_h1, *ptr_h1); ptr_h1++;
*p1-- = extract_h(cor);
cor = L_mac(cor, *ptr_h1, *ptr_h1); ptr_h1++;
cor = L_mac(cor, *ptr_h1, *ptr_h1); ptr_h1++;
*p0-- = extract_h(cor);
}
/*
* Compute elements of: rri0i1[], rri0i3[], rri1i2[] and rri2i3[]
*/
l_fin_sup = MSIZE-1;
l_fin_inf = l_fin_sup-(Word16)1;
ldec = NB_POS+1;
ptr_hd = h;
ptr_hf = ptr_hd + 2;
for(k=0; k<NB_POS; k++) {
p3 = rri2i3 + l_fin_sup;
p2 = rri1i2 + l_fin_sup;
p1 = rri0i1 + l_fin_sup;
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++;
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++;
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++;
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++;
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++;
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: rri0i2[], rri1i3[]
*/
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 = rri1i3 + l_fin_sup;
p2 = rri0i2 + l_fin_sup;
p1 = rri1i3 + l_fin_inf;
p0 = rri0i2 + 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++;
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++;
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++;
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++;
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: rri0i1[], rri0i3[], rri1i2[] and rri2i3[]
*/
ptr_hd = h;
ptr_hf = ptr_hd + 6;
l_fin_sup = MSIZE-1;
l_fin_inf = l_fin_sup-(Word16)1;
for(k=0; k<NB_POS; k++) {
p3 = rri0i3 + 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++;
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++;
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++;
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);
l_fin_sup -= NB_POS;
l_fin_inf--;
ptr_hf += STEP;
}
return;
}
/*
**
** Function: Corr_h_X()
**
** Description: Compute correlations of input response h[] with
** the target vector X[].
**
** Links to the text: Section 2.16
**
** Arguments:
**
** Word16 h[] Impulse response.
** Word16 X[] Target vector.
** Word16 D[] Correlations.
**
** Outputs:
**
** Word16 D[] Correlations.
**
** Return value: None
*/
void Cor_h_X(Word16 h[], Word16 X[], Word16 D[])
{
Word16 i, j;
Word32 s, max;
Word32 y32[SubFrLen];
/* first keep the result on 32 bits and find absolute maximum */
max = 0;
for (i = 0; i < SubFrLen; i++) {
s = 0;
for (j = i; j < SubFrLen; j++)
s = L_mac(s, X[j], h[j-i]);
y32[i] = s;
s = L_abs(s);
if(s > max) 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<SubFrLen; i++)
D[i] = extract_l( L_shr(y32[i], j) );
return;
}
/*
** Function: Reset_max_time()
**
** Description: This function should be called at the beginning
** of each frame.
**
** Links to the text: Section 2.16
**
** Arguments: None
**
** Inputs: None
**
** Outputs:
**
** Word16 extra
**
** Return value: None
**
*/
static Word16 extra;
void reset_max_time(void)
{
extra = 120;
return;
}
/*
**
** Function: D4i64_LBC
**
** Description: Algebraic codebook for LBC.
** -> 17 bits; 4 pulses in a frame of 60 samples
**
** The code length is 60, containing 4 nonzero pulses
** i0, i1, i2, i3. Each pulse can have 8 possible
** positions (positive or negative):
**
** i0 (+-1) : 0, 8, 16, 24, 32, 40, 48, 56
** i1 (+-1) : 2, 10, 18, 26, 34, 42, 50, 58
** i2 (+-1) : 4, 12, 20, 28, 36, 44, 52, (60)
** i3 (+-1) : 6, 14, 22, 30, 38, 46, 54, (62)
**
** All the pulse can be shifted by one.
** The last position of the last 2 pulses falls outside the
** frame and signifies that the pulse is not present.
** The threshold controls if a section of the innovative
** codebook should be searched or not.
**
** Links to the text: Section 2.16
**
** Input arguments:
**
** Word16 Dn[] Correlation between target vector and impulse response h[]
** Word16 rr[] Correlations of impulse response h[]
** Word16 h[] Impulse response of filters
**
** Output arguments:
**
** Word16 cod[] Selected algebraic codeword
** Word16 y[] Filtered codeword
** Word16 code_shift Shift of the codeword
** Word16 sign Signs of the 4 pulses.
**
** Return value:
**
** Word16 Index of selected codevector
**
*/
Word16 D4i64_LBC(Word16 Dn[], Word16 rr[], Word16 h[], Word16 cod[],
Word16 y[], Word16 *code_shift, Word16 *sign)
{
Word16 i0, i1, i2, i3, ip0, ip1, ip2, ip3;
Word16 i, j, time;
Word16 shif, shift;
Word16 ps0, ps1, ps2, ps3, alp, alp0;
Word32 alp1, alp2, alp3, L32;
Word16 ps0a, ps1a, ps2a;
Word16 ps3c, psc, alpha;
Word16 means, max0, max1, max2, thres;
Word16 *rri0i0, *rri1i1, *rri2i2, *rri3i3;
Word16 *rri0i1, *rri0i2, *rri0i3;
Word16 *rri1i2, *rri1i3, *rri2i3;
Word16 *ptr_ri0i0, *ptr_ri1i1, *ptr_ri2i2, *ptr_ri3i3;
Word16 *ptr_ri0i1, *ptr_ri0i2, *ptr_ri0i3;
Word16 *ptr_ri1i2, *ptr_ri1i3, *ptr_ri2i3;
Word16 *ptr1_ri0i1, *ptr1_ri0i2, *ptr1_ri0i3;
Word16 *ptr1_ri1i2, *ptr1_ri1i3, *ptr1_ri2i3;
Word16 p_sign[SubFrLen2/2];
/* Init pointers */
rri0i0 = rr;
rri1i1 = rri0i0 + NB_POS;
rri2i2 = rri1i1 + NB_POS;
rri3i3 = rri2i2 + NB_POS;
rri0i1 = rri3i3 + NB_POS;
rri0i2 = rri0i1 + MSIZE;
rri0i3 = rri0i2 + MSIZE;
rri1i2 = rri0i3 + MSIZE;
rri1i3 = rri1i2 + MSIZE;
rri2i3 = rri1i3 + MSIZE;
/*
* Extend the backward filtered target vector by zeros
*/
for (i = SubFrLen; i < SubFrLen2; i++) Dn[i] = 0;
/*
* Chose the sign of the impulse.
*/
for (i=0; i<SubFrLen; i+=2) {
if( add(Dn[i],Dn[i+1]) >= 0) {
p_sign[i/2] = 1;
}
else {
p_sign[i/2] = -1;
Dn[i] = -Dn[i];
Dn[i+1] = -Dn[i+1];
}
}
p_sign[30] = p_sign[31] = 1;
/*
* Compute the search threshold after three pulses
*/
/* odd positions */
/* Find maximum of Dn[i0]+Dn[i1]+Dn[i2] */
max0 = Dn[0];
max1 = Dn[2];
max2 = Dn[4];
for (i = 8; i < SubFrLen; i+=STEP) {
if (Dn[i] > max0) max0 = Dn[i];
if (Dn[i+2] > max1) max1 = Dn[i+2];
if (Dn[i+4] > max2) max2 = Dn[i+4];
}
max0 = add(max0, max1);
max0 = add(max0, max2);
/* Find means of Dn[i0]+Dn[i1]+Dn[i2] */
L32 = 0;
for (i = 0; i < SubFrLen; i+=STEP) {
L32 = L_mac(L32, Dn[i], 1);
L32 = L_mac(L32, Dn[i+2], 1);
L32 = L_mac(L32, Dn[i+4], 1);
}
means =extract_l( L_shr(L32, 4));
/* thres = means + (max0-means)*threshold; */
thres = sub(max0, means);
thres = mult(thres, threshold);
thres = add(thres, means);
/* even positions */
/* Find maximum of Dn[i0]+Dn[i1]+Dn[i2] */
max0 = Dn[1];
max1 = Dn[3];
max2 = Dn[5];
for (i = 9; i < SubFrLen; i+=STEP) {
if (Dn[i] > max0) max0 = Dn[i];
if (Dn[i+2] > max1) max1 = Dn[i+2];
if (Dn[i+4] > max2) max2 = Dn[i+4];
}
max0 = add(max0, max1);
max0 = add(max0, max2);
/* Find means of Dn[i0]+Dn[i1]+Dn[i2] */
L32 = 0;
for (i = 1; i < SubFrLen; i+=STEP) {
L32 = L_mac(L32, Dn[i], 1);
L32 = L_mac(L32, Dn[i+2], 1);
L32 = L_mac(L32, Dn[i+4], 1);
}
means =extract_l( L_shr(L32, 4));
/* max1 = means + (max0-means)*threshold */
max1 = sub(max0, means);
max1 = mult(max1, threshold);
max1 = add(max1, means);
/* Keep maximum threshold between odd and even position */
if(max1 > thres) thres = max1;
/*
* Modification of rrixiy[] to take signs into account.
*/
ptr_ri0i1 = rri0i1;
ptr_ri0i2 = rri0i2;
ptr_ri0i3 = rri0i3;
ptr1_ri0i1 = rri0i1;
ptr1_ri0i2 = rri0i2;
ptr1_ri0i3 = rri0i3;
for(i0=0; i0<SubFrLen/2; i0+=STEP/2) {
for(i1=2/2; i1<SubFrLen/2; i1+=STEP/2) {
*ptr_ri0i1++ = i_mult(*ptr1_ri0i1++,
i_mult(p_sign[i0], p_sign[i1]));
*ptr_ri0i2++ = i_mult(*ptr1_ri0i2++,
i_mult(p_sign[i0], p_sign[i1+1]));
*ptr_ri0i3++ = i_mult(*ptr1_ri0i3++,
i_mult(p_sign[i0], p_sign[i1+2?? 快捷鍵說明
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