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 ***************************************************************************/
39
BQ_2I_D16F32C15_TRC_WRA_01(Biquad_Instance_t * pInstance,LVM_INT16 * pDataIn,LVM_INT16 * pDataOut,LVM_INT16 NrSamples)40 void BQ_2I_D16F32C15_TRC_WRA_01 ( Biquad_Instance_t *pInstance,
41 LVM_INT16 *pDataIn,
42 LVM_INT16 *pDataOut,
43 LVM_INT16 NrSamples)
44 {
45 LVM_INT32 ynL,ynR,templ;
46 LVM_INT16 ii;
47 PFilter_State pBiquadState = (PFilter_State) pInstance;
48
49 for (ii = NrSamples; ii != 0; ii--)
50 {
51
52
53 /**************************************************************************
54 PROCESSING OF THE LEFT CHANNEL
55 ***************************************************************************/
56 /* ynL=A2 (Q15) * x(n-2)L (Q0) in Q15*/
57 ynL=(LVM_INT32)pBiquadState->coefs[0]* pBiquadState->pDelays[2];
58
59 /* ynL+=A1 (Q15) * x(n-1)L (Q0) in Q15*/
60 ynL+=(LVM_INT32)pBiquadState->coefs[1]* pBiquadState->pDelays[0];
61
62 /* ynL+=A0 (Q15) * x(n)L (Q0) in Q15*/
63 ynL+=(LVM_INT32)pBiquadState->coefs[2]* (*pDataIn);
64
65 /* ynL+= ( (-B2 (Q15) * y(n-2)L (Q16) )>>16) in Q15 */
66 MUL32x16INTO32(pBiquadState->pDelays[6],pBiquadState->coefs[3],templ,16)
67 ynL+=templ;
68
69 /* ynL+=( (-B1 (Q15) * y(n-1)L (Q16) )>>16) in Q15 */
70 MUL32x16INTO32(pBiquadState->pDelays[4],pBiquadState->coefs[4],templ,16)
71 ynL+=templ;
72
73 /**************************************************************************
74 PROCESSING OF THE RIGHT CHANNEL
75 ***************************************************************************/
76 /* ynR=A2 (Q15) * x(n-2)R (Q0) in Q15*/
77 ynR=(LVM_INT32)pBiquadState->coefs[0]*pBiquadState->pDelays[3];
78
79 /* ynR+=A1 (Q15) * x(n-1)R (Q0) in Q15*/
80 ynR+=(LVM_INT32)pBiquadState->coefs[1]*pBiquadState->pDelays[1];
81
82 /* ynR+=A0 (Q15) * x(n)R (Q0) in Q15*/
83 ynR+=(LVM_INT32)pBiquadState->coefs[2]*(*(pDataIn+1));
84
85 /* ynR+= ( (-B2 (Q15) * y(n-2)R (Q16) )>>16) in Q15 */
86 MUL32x16INTO32(pBiquadState->pDelays[7],pBiquadState->coefs[3],templ,16)
87 ynR+=templ;
88
89 /* ynR+=( (-B1 (Q15) * y(n-1)R (Q16) )>>16) in Q15 */
90 MUL32x16INTO32(pBiquadState->pDelays[5],pBiquadState->coefs[4],templ,16)
91 ynR+=templ;
92
93 /**************************************************************************
94 UPDATING THE DELAYS
95 ***************************************************************************/
96 pBiquadState->pDelays[7]=pBiquadState->pDelays[5]; /* y(n-2)R=y(n-1)R*/
97 pBiquadState->pDelays[6]=pBiquadState->pDelays[4]; /* y(n-2)L=y(n-1)L*/
98 pBiquadState->pDelays[3]=pBiquadState->pDelays[1]; /* x(n-2)R=x(n-1)R*/
99 pBiquadState->pDelays[2]=pBiquadState->pDelays[0]; /* x(n-2)L=x(n-1)L*/
100 pBiquadState->pDelays[5]=ynR<<1; /* Update y(n-1)R in Q16*/
101 pBiquadState->pDelays[4]=ynL<<1; /* Update y(n-1)L in Q16*/
102 pBiquadState->pDelays[0]=(*pDataIn); /* Update x(n-1)L in Q0*/
103 pDataIn++;
104 pBiquadState->pDelays[1]=(*pDataIn); /* Update x(n-1)R in Q0*/
105 pDataIn++;
106
107 /**************************************************************************
108 WRITING THE OUTPUT
109 ***************************************************************************/
110 *pDataOut=(LVM_INT16)(ynL>>15); /* Write Left output in Q0*/
111 pDataOut++;
112 *pDataOut=(LVM_INT16)(ynR>>15); /* Write Right ouput in Q0*/
113 pDataOut++;
114 }
115
116 }
117
118