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 /**************************************************************************
24 ASSUMPTIONS:
25 COEFS-
26 pBiquadState->coefs[0] is A2, pBiquadState->coefs[1] is A1
27 pBiquadState->coefs[2] is A0, pBiquadState->coefs[3] is -B2
28 pBiquadState->coefs[4] is -B1, these are in Q13 format
29
30 DELAYS-
31 pBiquadState->pDelays[0] is x(n-1)L in Q0 format
32 pBiquadState->pDelays[1] is x(n-1)R in Q0 format
33 pBiquadState->pDelays[2] is x(n-2)L in Q0 format
34 pBiquadState->pDelays[3] is x(n-2)R in Q0 format
35 pBiquadState->pDelays[4] is y(n-1)L in Q16 format
36 pBiquadState->pDelays[5] is y(n-1)R in Q16 format
37 pBiquadState->pDelays[6] is y(n-2)L in Q16 format
38 pBiquadState->pDelays[7] is y(n-2)R in Q16 format
39 ***************************************************************************/
40
BQ_2I_D16F32C13_TRC_WRA_01(Biquad_Instance_t * pInstance,LVM_INT16 * pDataIn,LVM_INT16 * pDataOut,LVM_INT16 NrSamples)41 void BQ_2I_D16F32C13_TRC_WRA_01 ( Biquad_Instance_t *pInstance,
42 LVM_INT16 *pDataIn,
43 LVM_INT16 *pDataOut,
44 LVM_INT16 NrSamples)
45 {
46 LVM_INT32 ynL,ynR,templ;
47 LVM_INT16 ii;
48 PFilter_State pBiquadState = (PFilter_State) pInstance;
49
50 for (ii = NrSamples; ii != 0; ii--)
51 {
52
53
54 /**************************************************************************
55 PROCESSING OF THE LEFT CHANNEL
56 ***************************************************************************/
57 /* ynL=A2 (Q13) * x(n-2)L (Q0) in Q13*/
58 ynL=(LVM_INT32)pBiquadState->coefs[0]* pBiquadState->pDelays[2];
59
60 /* ynL+=A1 (Q13) * x(n-1)L (Q0) in Q13*/
61 ynL+=(LVM_INT32)pBiquadState->coefs[1]* pBiquadState->pDelays[0];
62
63 /* ynL+=A0 (Q13) * x(n)L (Q0) in Q13*/
64 ynL+=(LVM_INT32)pBiquadState->coefs[2]* (*pDataIn);
65
66 /* ynL+= ( (-B2 (Q13) * y(n-2)L (Q16) )>>16) in Q13 */
67 MUL32x16INTO32(pBiquadState->pDelays[6],pBiquadState->coefs[3],templ,16)
68 ynL+=templ;
69
70 /* ynL+=( (-B1 (Q13) * y(n-1)L (Q16) )>>16) in Q13 */
71 MUL32x16INTO32(pBiquadState->pDelays[4],pBiquadState->coefs[4],templ,16)
72 ynL+=templ;
73
74 /**************************************************************************
75 PROCESSING OF THE RIGHT CHANNEL
76 ***************************************************************************/
77 /* ynR=A2 (Q13) * x(n-2)R (Q0) in Q13*/
78 ynR=(LVM_INT32)pBiquadState->coefs[0]*pBiquadState->pDelays[3];
79
80 /* ynR+=A1 (Q13) * x(n-1)R (Q0) in Q13*/
81 ynR+=(LVM_INT32)pBiquadState->coefs[1]*pBiquadState->pDelays[1];
82
83 /* ynR+=A0 (Q13) * x(n)R (Q0) in Q13*/
84 ynR+=(LVM_INT32)pBiquadState->coefs[2]*(*(pDataIn+1));
85
86 /* ynR+= ( (-B2 (Q13) * y(n-2)R (Q16) )>>16) in Q13*/
87 MUL32x16INTO32(pBiquadState->pDelays[7],pBiquadState->coefs[3],templ,16)
88 ynR+=templ;
89
90 /* ynR+=( (-B1 (Q13) * y(n-1)R (Q16) )>>16) in Q13 */
91 MUL32x16INTO32(pBiquadState->pDelays[5],pBiquadState->coefs[4],templ,16)
92 ynR+=templ;
93
94 /**************************************************************************
95 UPDATING THE DELAYS
96 ***************************************************************************/
97 pBiquadState->pDelays[7]=pBiquadState->pDelays[5]; /* y(n-2)R=y(n-1)R*/
98 pBiquadState->pDelays[6]=pBiquadState->pDelays[4]; /* y(n-2)L=y(n-1)L*/
99 pBiquadState->pDelays[3]=pBiquadState->pDelays[1]; /* x(n-2)R=x(n-1)R*/
100 pBiquadState->pDelays[2]=pBiquadState->pDelays[0]; /* x(n-2)L=x(n-1)L*/
101 pBiquadState->pDelays[5]=ynR<<3; /* Update y(n-1)R in Q16*/
102 pBiquadState->pDelays[4]=ynL<<3; /* Update y(n-1)L in Q16*/
103 pBiquadState->pDelays[0]=(*pDataIn); /* Update x(n-1)L in Q0*/
104 pDataIn++;
105 pBiquadState->pDelays[1]=(*pDataIn); /* Update x(n-1)R in Q0*/
106 pDataIn++;
107
108 /**************************************************************************
109 WRITING THE OUTPUT
110 ***************************************************************************/
111 *pDataOut=(LVM_INT16)(ynL>>13); /* Write Left output in Q0*/
112 pDataOut++;
113 *pDataOut=(LVM_INT16)(ynR>>13); /* Write Right ouput in Q0*/
114 pDataOut++;
115 }
116
117 }
118
119