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#include "BIQUAD.h"
19#include "FO_1I_D16F16Css_TRC_WRA_01_Private.h"
20#include "LVM_Macros.h"
21
22/**************************************************************************
23 ASSUMPTIONS:
24 COEFS-
25 pBiquadState->coefs[0] is A1,
26 pBiquadState->coefs[1] is A0,
27 pBiquadState->coefs[2] is -B1, these are in Q15 format
28
29 DELAYS-
30 pBiquadState->pDelays[0] is x(n-1)L in Q0 format
31 pBiquadState->pDelays[1] is y(n-1)L in Q0 format
32***************************************************************************/
33
34#ifdef BUILD_FLOAT
35void FO_1I_D16F16C15_TRC_WRA_01( Biquad_FLOAT_Instance_t       *pInstance,
36                                 LVM_FLOAT               *pDataIn,
37                                 LVM_FLOAT               *pDataOut,
38                                 LVM_INT16               NrSamples)
39    {
40        LVM_FLOAT  ynL;
41        LVM_INT16 ii;
42        PFilter_State_FLOAT pBiquadState = (PFilter_State_FLOAT) pInstance;
43
44         for (ii = NrSamples; ii != 0; ii--)
45         {
46
47            /**************************************************************************
48                            PROCESSING OF THE LEFT CHANNEL
49            ***************************************************************************/
50            // ynL=A1  * x(n-1)L
51            ynL = (LVM_FLOAT)pBiquadState->coefs[0] * pBiquadState->pDelays[0];
52
53            // ynL+=A0  * x(n)L
54            ynL += (LVM_FLOAT)pBiquadState->coefs[1] * (*pDataIn);
55
56            // ynL+=  (-B1  * y(n-1)L
57            ynL += (LVM_FLOAT)pBiquadState->coefs[2] * pBiquadState->pDelays[1];
58
59            /**************************************************************************
60                            UPDATING THE DELAYS
61            ***************************************************************************/
62            pBiquadState->pDelays[1] = ynL; // Update y(n-1)L
63            pBiquadState->pDelays[0] = (*pDataIn++); // Update x(n-1)L
64
65            /**************************************************************************
66                            WRITING THE OUTPUT
67            ***************************************************************************/
68            *pDataOut++ = (LVM_FLOAT)ynL; // Write Left output
69
70        }
71
72    }
73#else
74void FO_1I_D16F16C15_TRC_WRA_01( Biquad_Instance_t       *pInstance,
75                                 LVM_INT16               *pDataIn,
76                                 LVM_INT16               *pDataOut,
77                                 LVM_INT16               NrSamples)
78    {
79        LVM_INT32  ynL;
80        LVM_INT16 ii;
81        PFilter_State pBiquadState = (PFilter_State) pInstance;
82
83         for (ii = NrSamples; ii != 0; ii--)
84         {
85
86            /**************************************************************************
87                            PROCESSING OF THE LEFT CHANNEL
88            ***************************************************************************/
89            // ynL=A1 (Q15) * x(n-1)L (Q0) in Q15
90            ynL=(LVM_INT32)pBiquadState->coefs[0]* pBiquadState->pDelays[0];
91
92            // ynL+=A0 (Q15) * x(n)L (Q0) in Q15
93            ynL+=(LVM_INT32)pBiquadState->coefs[1]* (*pDataIn);
94
95            // ynL+=  (-B1 (Q15) * y(n-1)L (Q0) ) in Q15
96            ynL+=(LVM_INT32)pBiquadState->coefs[2]*pBiquadState->pDelays[1];
97
98
99            ynL=(LVM_INT16)(ynL>>15); // ynL in Q0 format
100            /**************************************************************************
101                            UPDATING THE DELAYS
102            ***************************************************************************/
103            pBiquadState->pDelays[1]=ynL; // Update y(n-1)L in Q0
104            pBiquadState->pDelays[0]=(*pDataIn++); // Update x(n-1)L in Q0
105
106            /**************************************************************************
107                            WRITING THE OUTPUT
108            ***************************************************************************/
109            *pDataOut++=(LVM_INT16)ynL; // Write Left output in Q0
110
111        }
112
113    }
114#endif
115