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 "LVM_Types.h"
23#include "LVM_Macros.h"
24#include "VectorArithmetic.h"
25
26/**********************************************************************************
27   FUNCTION DelayAllPass_32x32
28***********************************************************************************/
29
30void DelayAllPass_Sat_32x16To32(  LVM_INT32  *delay,                    /* Delay buffer */
31                                  LVM_UINT16 size,                      /* Delay size */
32                                  LVM_INT16 coeff,                      /* All pass filter coefficient */
33                                  LVM_UINT16 DelayOffset,               /* Simple delay offset */
34                                  LVM_UINT16 *pAllPassOffset,           /* All pass filter delay offset */
35                                  LVM_INT32  *dst,                      /* Source/destination */
36                                  LVM_INT16 n)                          /* Number of  samples */
37{
38    LVM_INT16   i;
39    LVM_UINT16   AllPassOffset = *pAllPassOffset;
40    LVM_INT32    temp;
41    LVM_INT32    a,b,c;
42
43    for (i = 0; i < n; i++)
44    {
45
46        MUL32x16INTO32(delay[AllPassOffset], coeff, temp, 15)
47        a = temp;
48        b = delay[DelayOffset];
49        DelayOffset++;
50
51        c = a + b;
52        if ((((c ^ a) & (c ^ b)) >> 31) != 0)  /* overflow / underflow */
53        {
54            if(a < 0)
55            {
56                c = 0x80000000l;
57            }
58            else
59            {
60                c = 0x7FFFFFFFl;
61            }
62        }
63        *dst = c;
64        dst++;
65
66
67        MUL32x16INTO32(c, -coeff, temp, 15)
68        a = temp;
69        b = delay[AllPassOffset];
70        c = a + b;
71        if ((((c ^ a) & (c ^ b)) >> 31)!=0)  /* overflow / underflow */
72        {
73            if(a < 0)
74            {
75                c = 0x80000000l;
76            }
77            else
78            {
79                c = 0x7FFFFFFFl;
80            }
81        }
82        delay[AllPassOffset] = c;
83        AllPassOffset++;
84
85        /* Make the delay buffer a circular buffer */
86        if (DelayOffset >= size)
87        {
88            DelayOffset = 0;
89        }
90
91        if (AllPassOffset >= size)
92        {
93            AllPassOffset = 0;
94        }
95    }
96
97    /* Update the offset */
98    *pAllPassOffset = AllPassOffset;
99
100    return;
101}
102
103/**********************************************************************************/
104
105