1 /*
2 * Copyright (C) 2004-2010 NXP Software
3 * Copyright (C) 2010 The Android Open Source Project
4 *
5 * Licensed under the Apache License, Version 2.0 (the "License");
6 * you may not use this file except in compliance with the License.
7 * You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17
18 /**********************************************************************************
19 INCLUDE FILES
20 ***********************************************************************************/
21
22 #include "VectorArithmetic.h"
23
24 /**********************************************************************************
25 FUNCTION DelayMix_16x16
26 ***********************************************************************************/
27
DelayMix_16x16(const LVM_INT16 * src,LVM_INT16 * delay,LVM_INT16 size,LVM_INT16 * dst,LVM_INT16 * pOffset,LVM_INT16 n)28 void DelayMix_16x16(const LVM_INT16 *src, /* Source 1, to be delayed */
29 LVM_INT16 *delay, /* Delay buffer */
30 LVM_INT16 size, /* Delay size */
31 LVM_INT16 *dst, /* Source/destination */
32 LVM_INT16 *pOffset, /* Delay offset */
33 LVM_INT16 n) /* Number of stereo samples */
34 {
35 LVM_INT16 i;
36 LVM_INT16 Offset = *pOffset;
37 LVM_INT16 temp;
38
39 for (i=0; i<n; i++)
40 {
41 /* Left channel */
42 temp = (LVM_INT16)((LVM_UINT32)((LVM_INT32)(*dst) + (LVM_INT32)delay[Offset]) >> 1);
43 *dst = temp;
44 dst++;
45
46 delay[Offset] = *src;
47 Offset++;
48 src++;
49
50
51 /* Right channel */
52 temp = (LVM_INT16)((LVM_UINT32)((LVM_INT32)(*dst) - (LVM_INT32)delay[Offset]) >> 1);
53 *dst = temp;
54 dst++;
55
56 delay[Offset] = *src;
57 Offset++;
58 src++;
59
60 /* Make the reverb delay buffer a circular buffer */
61 if (Offset >= size)
62 {
63 Offset = 0;
64 }
65 }
66
67 /* Update the offset */
68 *pOffset = Offset;
69
70 return;
71 }
72
73 /**********************************************************************************/
74