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 "BP_1I_D16F32Cll_TRC_WRA_01_Private.h"
20#include "LVM_Macros.h"
21
22
23/**************************************************************************
24 ASSUMPTIONS:
25 COEFS-
26 pBiquadState->coefs[0] is A0,
27 pBiquadState->coefs[1] is -B2,
28 pBiquadState->coefs[2] is -B1, these are in Q30 format
29
30 DELAYS-
31 pBiquadState->pDelays[0] is x(n-1)L in Q0 format
32 pBiquadState->pDelays[1] is x(n-2)L in Q0 format
33 pBiquadState->pDelays[2] is y(n-1)L in Q16 format
34 pBiquadState->pDelays[3] is y(n-2)L in Q16 format
35***************************************************************************/
36
37void BP_1I_D16F32C30_TRC_WRA_01 ( Biquad_Instance_t       *pInstance,
38                                  LVM_INT16               *pDataIn,
39                                  LVM_INT16               *pDataOut,
40                                  LVM_INT16               NrSamples)
41
42
43    {
44        LVM_INT32 ynL,templ;
45        LVM_INT16 ii;
46        PFilter_State pBiquadState = (PFilter_State) pInstance;
47
48         for (ii = NrSamples; ii != 0; ii--)
49         {
50
51
52            /**************************************************************************
53                            PROCESSING OF THE LEFT CHANNEL
54            ***************************************************************************/
55            // ynL= (A0 (Q30) * (x(n)L (Q0) - x(n-2)L (Q0) ) >>14)  in Q16
56            templ= (LVM_INT32) *pDataIn-pBiquadState->pDelays[1];
57            MUL32x32INTO32(pBiquadState->coefs[0],templ,ynL,14)
58
59            // ynL+= ((-B2 (Q30) * y(n-2)L (Q16) ) >>30) in Q16
60            MUL32x32INTO32(pBiquadState->coefs[1],pBiquadState->pDelays[3],templ,30)
61            ynL+=templ;
62
63            // ynL+= ((-B1 (Q30) * y(n-1)L (Q16) ) >>30) in Q16
64            MUL32x32INTO32(pBiquadState->coefs[2],pBiquadState->pDelays[2],templ,30)
65            ynL+=templ;
66
67            /**************************************************************************
68                            UPDATING THE DELAYS
69            ***************************************************************************/
70            pBiquadState->pDelays[3]=pBiquadState->pDelays[2]; // y(n-2)L=y(n-1)L
71            pBiquadState->pDelays[1]=pBiquadState->pDelays[0]; // x(n-2)L=x(n-1)L
72            pBiquadState->pDelays[2]=ynL; // Update y(n-1)L in Q16
73            pBiquadState->pDelays[0]=(*pDataIn++); // Update x(n-1)L in Q0
74
75            /**************************************************************************
76                            WRITING THE OUTPUT
77            ***************************************************************************/
78            *pDataOut++=(LVM_INT16)(ynL>>16); // Write Left output in Q0
79
80        }
81
82    }
83
84