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
41void 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