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 Q14 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
40void BQ_2I_D16F32C14_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 (Q14) * x(n-2)L (Q0) in Q14*/
57            ynL=(LVM_INT32)pBiquadState->coefs[0]* pBiquadState->pDelays[2];
58
59            /* ynL+=A1 (Q14) * x(n-1)L (Q0) in Q14*/
60            ynL+=(LVM_INT32)pBiquadState->coefs[1]* pBiquadState->pDelays[0];
61
62            /* ynL+=A0 (Q14) * x(n)L (Q0) in Q14*/
63            ynL+=(LVM_INT32)pBiquadState->coefs[2]* (*pDataIn);
64
65            /* ynL+= ( (-B2 (Q14) * y(n-2)L (Q16) )>>16) in Q14 */
66            MUL32x16INTO32(pBiquadState->pDelays[6],pBiquadState->coefs[3],templ,16)
67            ynL+=templ;
68
69            /* ynL+=( (-B1 (Q14) * y(n-1)L (Q16) )>>16) in Q14 */
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 (Q14) * x(n-2)R (Q0) in Q14*/
77            ynR=(LVM_INT32)pBiquadState->coefs[0]*pBiquadState->pDelays[3];
78
79            /* ynR+=A1 (Q14) * x(n-1)R (Q0) in Q14*/
80            ynR+=(LVM_INT32)pBiquadState->coefs[1]*pBiquadState->pDelays[1];
81
82            /* ynR+=A0 (Q14) * x(n)R (Q0) in Q14*/
83            ynR+=(LVM_INT32)pBiquadState->coefs[2]*(*(pDataIn+1));
84
85            /* ynR+= ( (-B2 (Q14) * y(n-2)R (Q16) )>>16) in Q14*/
86            MUL32x16INTO32(pBiquadState->pDelays[7],pBiquadState->coefs[3],templ,16)
87            ynR+=templ;
88
89            /* ynR+=( (-B1 (Q14) * y(n-1)R (Q16) )>>16) in Q14 */
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<<2;                    /* Update y(n-1)R in Q16*/
101            pBiquadState->pDelays[4]=ynL<<2;                    /* 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>>14); /* Write Left output in Q0*/
111            pDataOut++;
112            *pDataOut=(LVM_INT16)(ynR>>14); /* Write Right ouput in Q0*/
113            pDataOut++;
114        }
115
116    }
117
118