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/*
** Copyright 2003-2010, VisualOn, Inc.
**
** Licensed under the Apache License, Version 2.0 (the "License");
** you may not use this file except in compliance with the License.
** You may obtain a copy of the License at
**
** http://www.apache.org/licenses/LICENSE-2.0
**
** Unless required by applicable law or agreed to in writing, software
** distributed under the License is distributed on an "AS IS" BASIS,
** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
** See the License for the specific language governing permissions and
** limitations under the License.
*/
/************************************************************************
* File: c2t64fx.c *
* *
* Description:Performs algebraic codebook search for 6.60kbits mode*
* *
*************************************************************************/
#include "typedef.h"
#include "basic_op.h"
#include "math_op.h"
#include "acelp.h"
#include "cnst.h"
#define NB_TRACK 2
#define STEP 2
#define NB_POS 32
#define MSIZE 1024
/*************************************************************************
* Function: ACELP_2t64_fx() *
* *
* 12 bits algebraic codebook. *
* 2 tracks x 32 positions per track = 64 samples. *
* *
* 12 bits --> 2 pulses in a frame of 64 samples. *
* *
* All pulses can have two (2) possible amplitudes: +1 or -1. *
* Each pulse can have 32 possible positions. *
**************************************************************************/
void ACELP_2t64_fx(
Word16 dn[], /* (i) <12b : correlation between target x[] and H[] */
Word16 cn[], /* (i) <12b : residual after long term prediction */
Word16 H[], /* (i) Q12: impulse response of weighted synthesis filter */
Word16 code[], /* (o) Q9 : algebraic (fixed) codebook excitation */
Word16 y[], /* (o) Q9 : filtered fixed codebook excitation */
Word16 * index /* (o) : index (12): 5+1+5+1 = 11 bits. */
)
{
Word32 i, j, k, i0, i1, ix, iy, pos, pos2;
Word16 ps, psk, ps1, ps2, alpk, alp1, alp2, sq;
Word16 alp, val, exp, k_cn, k_dn;
Word16 *p0, *p1, *p2, *psign;
Word16 *h, *h_inv, *ptr_h1, *ptr_h2, *ptr_hf;
Word16 sign[L_SUBFR], vec[L_SUBFR], dn2[L_SUBFR];
Word16 h_buf[4 * L_SUBFR] = {0};
Word16 rrixix[NB_TRACK][NB_POS];
Word16 rrixiy[MSIZE];
Word32 s, cor;
/*----------------------------------------------------------------*
* Find sign for each pulse position. *
*----------------------------------------------------------------*/
alp = 8192; /* alp = 2.0 (Q12) */
/* calculate energy for normalization of cn[] and dn[] */
/* set k_cn = 32..32767 (ener_cn = 2^30..256-0) */
#ifdef ASM_OPT /* asm optimization branch */
s = Dot_product12_asm(cn, cn, L_SUBFR, &exp);
#else
s = Dot_product12(cn, cn, L_SUBFR, &exp);
#endif
Isqrt_n(&s, &exp);
s = L_shl(s, add1(exp, 5));
if (s > INT_MAX - 0x8000) {
s = INT_MAX - 0x8000;
}
k_cn = vo_round(s);
/* set k_dn = 32..512 (ener_dn = 2^30..2^22) */
#ifdef ASM_OPT /* asm optimization branch */
s = Dot_product12_asm(dn, dn, L_SUBFR, &exp);
#else
s = Dot_product12(dn, dn, L_SUBFR, &exp);
#endif
Isqrt_n(&s, &exp);
k_dn = vo_round(L_shl(s, (exp + 8))); /* k_dn = 256..4096 */
k_dn = vo_mult_r(alp, k_dn); /* alp in Q12 */
/* mix normalized cn[] and dn[] */
p0 = cn;
p1 = dn;
p2 = dn2;
for (i = 0; i < L_SUBFR/4; i++)
{
s = (k_cn* (*p0++))+(k_dn * (*p1++));
*p2++ = s >> 7;
s = (k_cn* (*p0++))+(k_dn * (*p1++));
*p2++ = s >> 7;
s = (k_cn* (*p0++))+(k_dn * (*p1++));
*p2++ = s >> 7;
s = (k_cn* (*p0++))+(k_dn * (*p1++));
*p2++ = s >> 7;
}
/* set sign according to dn2[] = k_cn*cn[] + k_dn*dn[] */
for (i = 0; i < L_SUBFR; i ++)
{
val = dn[i];
ps = dn2[i];
if (ps >= 0)
{
sign[i] = 32767; /* sign = +1 (Q12) */
vec[i] = -32768;
} else
{
sign[i] = -32768; /* sign = -1 (Q12) */
vec[i] = 32767;
dn[i] = -val;
}
}
/*------------------------------------------------------------*
* Compute h_inv[i]. *
*------------------------------------------------------------*/
/* impulse response buffer for fast computation */
h = h_buf + L_SUBFR;
h_inv = h + (L_SUBFR<<1);
for (i = 0; i < L_SUBFR; i++)
{
h[i] = H[i];
h_inv[i] = vo_negate(h[i]);
}
/*------------------------------------------------------------*
* Compute rrixix[][] needed for the codebook search. *
* Result is multiplied by 0.5 *
*------------------------------------------------------------*/
/* Init pointers to last position of rrixix[] */
p0 = &rrixix[0][NB_POS - 1];
p1 = &rrixix[1][NB_POS - 1];
ptr_h1 = h;
cor = 0x00010000L; /* for rounding */
for (i = 0; i < NB_POS; i++)
{
cor += ((*ptr_h1) * (*ptr_h1) << 1);
ptr_h1++;
*p1-- = (extract_h(cor) >> 1);
cor += ((*ptr_h1) * (*ptr_h1) << 1);
ptr_h1++;
*p0-- = (extract_h(cor) >> 1);
}
/*------------------------------------------------------------*
* Compute rrixiy[][] needed for the codebook search. *
*------------------------------------------------------------*/
pos = MSIZE - 1;
pos2 = MSIZE - 2;
ptr_hf = h + 1;
for (k = 0; k < NB_POS; k++)
{
p1 = &rrixiy[pos];
p0 = &rrixiy[pos2];
cor = 0x00008000L; /* for rounding */
ptr_h1 = h;
ptr_h2 = ptr_hf;
for (i = (k + 1); i < NB_POS; i++)
{
cor += ((*ptr_h1) * (*ptr_h2))<<1;
ptr_h1++;
ptr_h2++;
*p1 = extract_h(cor);
cor += ((*ptr_h1) * (*ptr_h2))<<1;
ptr_h1++;
ptr_h2++;
*p0 = extract_h(cor);
p1 -= (NB_POS + 1);
p0 -= (NB_POS + 1);
}
cor += ((*ptr_h1) * (*ptr_h2))<<1;
ptr_h1++;
ptr_h2++;
*p1 = extract_h(cor);
pos -= NB_POS;
pos2--;
ptr_hf += STEP;
}
/*------------------------------------------------------------*
* Modification of rrixiy[][] to take signs into account. *
*------------------------------------------------------------*/
p0 = rrixiy;
for (i = 0; i < L_SUBFR; i += STEP)
{
psign = sign;
if (psign[i] < 0)
{
psign = vec;
}
for (j = 1; j < L_SUBFR; j += STEP)
{
*p0 = vo_mult(*p0, psign[j]);
p0++;
}
}
/*-------------------------------------------------------------------*
* search 2 pulses: *
* ~@~~~~~~~~~~~~~~ *
* 32 pos x 32 pos = 1024 tests (all combinaisons is tested) *
*-------------------------------------------------------------------*/
p0 = rrixix[0];
p1 = rrixix[1];
p2 = rrixiy;
psk = -1;
alpk = 1;
ix = 0;
iy = 1;
for (i0 = 0; i0 < L_SUBFR; i0 += STEP)
{
ps1 = dn[i0];
alp1 = (*p0++);
pos = -1;
for (i1 = 1; i1 < L_SUBFR; i1 += STEP)
{
ps2 = add1(ps1, dn[i1]);
alp2 = add1(alp1, add1(*p1++, *p2++));
sq = vo_mult(ps2, ps2);
s = vo_L_mult(alpk, sq) - ((psk * alp2)<<1);
if (s > 0)
{
psk = sq;
alpk = alp2;
pos = i1;
}
}
p1 -= NB_POS;
if (pos >= 0)
{
ix = i0;
iy = pos;
}
}
/*-------------------------------------------------------------------*
* Build the codeword, the filtered codeword and index of codevector.*
*-------------------------------------------------------------------*/
for (i = 0; i < L_SUBFR; i++)
{
code[i] = 0;
}
i0 = (ix >> 1); /* pos of pulse 1 (0..31) */
i1 = (iy >> 1); /* pos of pulse 2 (0..31) */
if (sign[ix] > 0)
{
code[ix] = 512; /* codeword in Q9 format */
p0 = h - ix;
} else
{
code[ix] = -512;
i0 += NB_POS;
p0 = h_inv - ix;
}
if (sign[iy] > 0)
{
code[iy] = 512;
p1 = h - iy;
} else
{
code[iy] = -512;
i1 += NB_POS;
p1 = h_inv - iy;
}
*index = add1((i0 << 6), i1);
for (i = 0; i < L_SUBFR; i++)
{
y[i] = vo_shr_r(add1((*p0++), (*p1++)), 3);
}
return;
}
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