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