diff options
Diffstat (limited to 'media/libstagefright/codecs/amrwbenc/src/weight_a.c')
-rw-r--r-- | media/libstagefright/codecs/amrwbenc/src/weight_a.c | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/media/libstagefright/codecs/amrwbenc/src/weight_a.c b/media/libstagefright/codecs/amrwbenc/src/weight_a.c new file mode 100644 index 0000000..a02b48d --- /dev/null +++ b/media/libstagefright/codecs/amrwbenc/src/weight_a.c @@ -0,0 +1,48 @@ +/* + ** 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; +} + + + |