/* | |
** 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: residu.c * | |
* * | |
* Description: Compute the LPC residual by filtering * | |
* the input speech through A(z) * | |
* * | |
************************************************************************/ | |
#include "typedef.h" | |
#include "basic_op.h" | |
void Residu( | |
Word16 a[], /* (i) Q12 : prediction coefficients */ | |
Word16 x[], /* (i) : speech (values x[-m..-1] are needed */ | |
Word16 y[], /* (o) x2 : residual signal */ | |
Word16 lg /* (i) : size of filtering */ | |
) | |
{ | |
Word16 i,*p1, *p2; | |
Word32 s; | |
for (i = 0; i < lg; i++) | |
{ | |
p1 = a; | |
p2 = &x[i]; | |
s = vo_mult32((*p1++), (*p2--)); | |
s += vo_mult32((*p1++), (*p2--)); | |
s += vo_mult32((*p1++), (*p2--)); | |
s += vo_mult32((*p1++), (*p2--)); | |
s += vo_mult32((*p1++), (*p2--)); | |
s += vo_mult32((*p1++), (*p2--)); | |
s += vo_mult32((*p1++), (*p2--)); | |
s += vo_mult32((*p1++), (*p2--)); | |
s += vo_mult32((*p1++), (*p2--)); | |
s += vo_mult32((*p1++), (*p2--)); | |
s += vo_mult32((*p1++), (*p2--)); | |
s += vo_mult32((*p1++), (*p2--)); | |
s += vo_mult32((*p1++), (*p2--)); | |
s += vo_mult32((*p1++), (*p2--)); | |
s += vo_mult32((*p1++), (*p2--)); | |
s += vo_mult32((*p1++), (*p2--)); | |
s += vo_mult32((*p1), (*p2)); | |
s = L_shl2(s, 5); | |
y[i] = extract_h(L_add(s, 0x8000)); | |
} | |
return; | |
} | |