/* | |
** 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" | |
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; | |
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; | |
} | |