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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: syn_filt.c *
* *
* Description: Do the synthesis filtering 1/A(z) *
* *
************************************************************************/
#include "typedef.h"
#include "basic_op.h"
#include "math_op.h"
#include "cnst.h"
#define UNUSED(x) (void)(x)
void Syn_filt(
Word16 a[], /* (i) Q12 : a[m+1] prediction coefficients */
Word16 x[], /* (i) : input signal */
Word16 y[], /* (o) : output signal */
Word16 lg, /* (i) : size of filtering */
Word16 mem[], /* (i/o) : memory associated with this filtering. */
Word16 update /* (i) : 0=no update, 1=update of memory. */
)
{
Word32 i, a0;
Word16 y_buf[L_SUBFR16k + M16k];
Word32 L_tmp;
Word16 *yy, *p1, *p2;
yy = &y_buf[0];
/* copy initial filter states into synthesis buffer */
for (i = 0; i < 16; i++)
{
*yy++ = mem[i];
}
a0 = (a[0] >> 1); /* input / 2 */
/* Do the filtering. */
for (i = 0; i < lg; i++)
{
p1 = &a[1];
p2 = &yy[i-1];
L_tmp = vo_mult32(a0, x[i]);
L_tmp -= vo_mult32((*p1++), (*p2--));
L_tmp -= vo_mult32((*p1++), (*p2--));
L_tmp -= vo_mult32((*p1++), (*p2--));
L_tmp -= vo_mult32((*p1++), (*p2--));
L_tmp -= vo_mult32((*p1++), (*p2--));
L_tmp -= vo_mult32((*p1++), (*p2--));
L_tmp -= vo_mult32((*p1++), (*p2--));
L_tmp -= vo_mult32((*p1++), (*p2--));
L_tmp -= vo_mult32((*p1++), (*p2--));
L_tmp -= vo_mult32((*p1++), (*p2--));
L_tmp -= vo_mult32((*p1++), (*p2--));
L_tmp -= vo_mult32((*p1++), (*p2--));
L_tmp -= vo_mult32((*p1++), (*p2--));
L_tmp -= vo_mult32((*p1++), (*p2--));
L_tmp -= vo_mult32((*p1++), (*p2--));
L_tmp -= vo_mult32((*p1), (*p2));
L_tmp = L_shl2(L_tmp, 4);
y[i] = yy[i] = extract_h(L_add(L_tmp, 0x8000));
}
/* Update memory if required */
if (update)
for (i = 0; i < 16; i++)
{
mem[i] = yy[lg - 16 + i];
}
return;
}
void Syn_filt_32(
Word16 a[], /* (i) Q12 : a[m+1] prediction coefficients */
Word16 m, /* (i) : order of LP filter */
Word16 exc[], /* (i) Qnew: excitation (exc[i] >> Qnew) */
Word16 Qnew, /* (i) : exc scaling = 0(min) to 8(max) */
Word16 sig_hi[], /* (o) /16 : synthesis high */
Word16 sig_lo[], /* (o) /16 : synthesis low */
Word16 lg /* (i) : size of filtering */
)
{
Word32 i,a0;
Word32 L_tmp, L_tmp1;
Word16 *p1, *p2, *p3;
UNUSED(m);
a0 = a[0] >> (4 + Qnew); /* input / 16 and >>Qnew */
/* Do the filtering. */
for (i = 0; i < lg; i++)
{
L_tmp = 0;
L_tmp1 = 0;
p1 = a;
p2 = &sig_lo[i - 1];
p3 = &sig_hi[i - 1];
L_tmp -= vo_mult32((*p2--), (*p1));
L_tmp1 -= vo_mult32((*p3--), (*p1++));
L_tmp -= vo_mult32((*p2--), (*p1));
L_tmp1 -= vo_mult32((*p3--), (*p1++));
L_tmp -= vo_mult32((*p2--), (*p1));
L_tmp1 -= vo_mult32((*p3--), (*p1++));
L_tmp -= vo_mult32((*p2--), (*p1));
L_tmp1 -= vo_mult32((*p3--), (*p1++));
L_tmp -= vo_mult32((*p2--), (*p1));
L_tmp1 -= vo_mult32((*p3--), (*p1++));
L_tmp -= vo_mult32((*p2--), (*p1));
L_tmp1 -= vo_mult32((*p3--), (*p1++));
L_tmp -= vo_mult32((*p2--), (*p1));
L_tmp1 -= vo_mult32((*p3--), (*p1++));
L_tmp -= vo_mult32((*p2--), (*p1));
L_tmp1 -= vo_mult32((*p3--), (*p1++));
L_tmp -= vo_mult32((*p2--), (*p1));
L_tmp1 -= vo_mult32((*p3--), (*p1++));
L_tmp -= vo_mult32((*p2--), (*p1));
L_tmp1 -= vo_mult32((*p3--), (*p1++));
L_tmp -= vo_mult32((*p2--), (*p1));
L_tmp1 -= vo_mult32((*p3--), (*p1++));
L_tmp -= vo_mult32((*p2--), (*p1));
L_tmp1 -= vo_mult32((*p3--), (*p1++));
L_tmp -= vo_mult32((*p2--), (*p1));
L_tmp1 -= vo_mult32((*p3--), (*p1++));
L_tmp -= vo_mult32((*p2--), (*p1));
L_tmp1 -= vo_mult32((*p3--), (*p1++));
L_tmp -= vo_mult32((*p2--), (*p1));
L_tmp1 -= vo_mult32((*p3--), (*p1++));
L_tmp -= vo_mult32((*p2--), (*p1));
L_tmp1 -= vo_mult32((*p3--), (*p1++));
L_tmp = L_tmp >> 11;
L_tmp += vo_L_mult(exc[i], a0);
/* sig_hi = bit16 to bit31 of synthesis */
L_tmp = L_tmp - (L_tmp1<<1);
L_tmp = L_tmp >> 3; /* ai in Q12 */
sig_hi[i] = extract_h(L_tmp);
/* sig_lo = bit4 to bit15 of synthesis */
L_tmp >>= 4; /* 4 : sig_lo[i] >> 4 */
sig_lo[i] = (Word16)((L_tmp - (sig_hi[i] << 13)));
}
return;
}
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