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 "BQ_2I_D16F32Css_TRC_WRA_01_Private.h"
20 #include "LVM_Macros.h"
21
22 /**************************************************************************
23 ASSUMPTIONS:
24 COEFS-
25 pBiquadState->coefs[0] is A2, pBiquadState->coefs[1] is A1
26 pBiquadState->coefs[2] is A0, pBiquadState->coefs[3] is -B2
27 pBiquadState->coefs[4] 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 x(n-1)R in Q0 format
32 pBiquadState->pDelays[2] is x(n-2)L in Q0 format
33 pBiquadState->pDelays[3] is x(n-2)R in Q0 format
34 pBiquadState->pDelays[4] is y(n-1)L in Q16 format
35 pBiquadState->pDelays[5] is y(n-1)R in Q16 format
36 pBiquadState->pDelays[6] is y(n-2)L in Q16 format
37 pBiquadState->pDelays[7] is y(n-2)R in Q16 format
38 ***************************************************************************/
BQ_2I_D16F32C15_TRC_WRA_01(Biquad_FLOAT_Instance_t * pInstance,LVM_FLOAT * pDataIn,LVM_FLOAT * pDataOut,LVM_INT16 NrSamples)39 void BQ_2I_D16F32C15_TRC_WRA_01 ( Biquad_FLOAT_Instance_t *pInstance,
40 LVM_FLOAT *pDataIn,
41 LVM_FLOAT *pDataOut,
42 LVM_INT16 NrSamples)
43 {
44 LVM_FLOAT ynL,ynR;
45 LVM_INT16 ii;
46 PFilter_State_FLOAT pBiquadState = (PFilter_State_FLOAT) pInstance;
47
48 for (ii = NrSamples; ii != 0; ii--)
49 {
50
51 /**************************************************************************
52 PROCESSING OF THE LEFT CHANNEL
53 ***************************************************************************/
54 /* ynL=A2 * x(n-2)L */
55 ynL = (LVM_FLOAT)pBiquadState->coefs[0] * pBiquadState->pDelays[2];
56
57 /* ynL+=A1 * x(n-1)L */
58 ynL += (LVM_FLOAT)pBiquadState->coefs[1] * pBiquadState->pDelays[0];
59
60 /* ynL+=A0 * x(n)L */
61 ynL += (LVM_FLOAT)pBiquadState->coefs[2] * (*pDataIn);
62
63 /* ynL+= ( (-B2 * y(n-2)L ) */
64 ynL += pBiquadState->pDelays[6] * pBiquadState->coefs[3];
65
66 /* ynL+=( (-B1 * y(n-1)L )) */
67 ynL += pBiquadState->pDelays[4] * pBiquadState->coefs[4];
68
69 /**************************************************************************
70 PROCESSING OF THE RIGHT CHANNEL
71 ***************************************************************************/
72 /* ynR=A2 * x(n-2)R */
73 ynR = (LVM_FLOAT)pBiquadState->coefs[0] * pBiquadState->pDelays[3];
74
75 /* ynR+=A1 * x(n-1)R */
76 ynR += (LVM_FLOAT)pBiquadState->coefs[1] * pBiquadState->pDelays[1];
77
78 /* ynR+=A0 * x(n)R */
79 ynR += (LVM_FLOAT)pBiquadState->coefs[2] * (*(pDataIn+1));
80
81 /* ynR+= ( (-B2 * y(n-2)R ) */
82 ynR += pBiquadState->pDelays[7] * pBiquadState->coefs[3];
83
84 /* ynR+=( (-B1 * y(n-1)R )) in Q15 */
85 ynR += pBiquadState->pDelays[5] * pBiquadState->coefs[4];
86
87 /**************************************************************************
88 UPDATING THE DELAYS
89 ***************************************************************************/
90 pBiquadState->pDelays[7] = pBiquadState->pDelays[5]; /* y(n-2)R=y(n-1)R*/
91 pBiquadState->pDelays[6] = pBiquadState->pDelays[4]; /* y(n-2)L=y(n-1)L*/
92 pBiquadState->pDelays[3] = pBiquadState->pDelays[1]; /* x(n-2)R=x(n-1)R*/
93 pBiquadState->pDelays[2] = pBiquadState->pDelays[0]; /* x(n-2)L=x(n-1)L*/
94 pBiquadState->pDelays[5] = ynR; /* Update y(n-1)R*/
95 pBiquadState->pDelays[4] = ynL; /* Update y(n-1)L*/
96 pBiquadState->pDelays[0] = (*pDataIn); /* Update x(n-1)L*/
97 pDataIn++;
98 pBiquadState->pDelays[1] = (*pDataIn); /* Update x(n-1)R*/
99 pDataIn++;
100
101 /**************************************************************************
102 WRITING THE OUTPUT
103 ***************************************************************************/
104 *pDataOut = (LVM_FLOAT)(ynL); /* Write Left output*/
105 pDataOut++;
106 *pDataOut = (LVM_FLOAT)(ynR); /* Write Right ouput*/
107 pDataOut++;
108 }
109
110 }
111