| /* |
| ** 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: weight_a.c * |
| * * |
| * Description:Weighting of LPC coefficients * |
| * ap[i] = a[i] * (gamma ** i) * |
| * * |
| ************************************************************************/ |
| |
| #include "typedef.h" |
| #include "basic_op.h" |
| |
| void Weight_a( |
| Word16 a[], /* (i) Q12 : a[m+1] LPC coefficients */ |
| Word16 ap[], /* (o) Q12 : Spectral expanded LPC coefficients */ |
| Word16 gamma, /* (i) Q15 : Spectral expansion factor. */ |
| Word16 m /* (i) : LPC order. */ |
| ) |
| { |
| Word32 num = m - 1, fac; |
| *ap++ = *a++; |
| fac = gamma; |
| do{ |
| *ap++ =(Word16)(((vo_L_mult((*a++), fac)) + 0x8000) >> 16); |
| fac = (vo_L_mult(fac, gamma) + 0x8000) >> 16; |
| }while(--num != 0); |
| |
| *ap++ = (Word16)(((vo_L_mult((*a++), fac)) + 0x8000) >> 16); |
| return; |
| } |
| |
| |
| |