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..d47be97 --- /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;
+}
+
+
+
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