BQ_1I_D16F32C14_TRC_WRA_01.c revision 2c8e5cab3faa6d360e222b7a6c40a80083d021ac 
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/************************************************************************/
19/*                                                                      */
20/*     Project::                                                        */
21/*     $Author: beq07716 $*/
22/*     $Revision: 1000 $*/
23/*     $Date: 2010-06-28 13:08:20 +0200 (Mon, 28 Jun 2010) $*/
24/*                                                                      */
25/************************************************************************/
26
27#include "BIQUAD.h"
28#include "BQ_1I_D16F32Css_TRC_WRA_01_Private.h"
29#include "LVM_Macros.h"
30
31/**************************************************************************
32 ASSUMPTIONS:
33 COEFS-
34 pBiquadState->coefs[0] is A2, pBiquadState->coefs[1] is A1
35 pBiquadState->coefs[2] is A0, pBiquadState->coefs[3] is -B2
36 pBiquadState->coefs[4] is -B1, these are in Q14 format
37
38 DELAYS-
39 pBiquadState->pDelays[0] is x(n-1)L in Q0 format
40 pBiquadState->pDelays[1] is x(n-2)L in Q0 format
41 pBiquadState->pDelays[2] is y(n-1)L in Q16 format
42 pBiquadState->pDelays[3] is y(n-2)L in Q16 format
43***************************************************************************/
44
45void BQ_1I_D16F32C14_TRC_WRA_01 ( Biquad_Instance_t       *pInstance,
46                                  LVM_INT16               *pDataIn,
47                                  LVM_INT16               *pDataOut,
48                                  LVM_INT16               NrSamples)
49    {
50        LVM_INT32  ynL,templ;
51        LVM_INT16 ii;
52        PFilter_State pBiquadState = (PFilter_State) pInstance;
53
54         for (ii = NrSamples; ii != 0; ii--)
55         {
56
57
58            /**************************************************************************
59                            PROCESSING OF THE LEFT CHANNEL
60            ***************************************************************************/
61            // ynL=A2 (Q14) * x(n-2)L (Q0) in Q14
62            ynL=(LVM_INT32)pBiquadState->coefs[0]* pBiquadState->pDelays[1];
63
64            // ynL+=A1 (Q14) * x(n-1)L (Q0) in Q14
65            ynL+=(LVM_INT32)pBiquadState->coefs[1]* pBiquadState->pDelays[0];
66
67            // ynL+=A0 (Q14) * x(n)L (Q0) in Q14
68            ynL+=(LVM_INT32)pBiquadState->coefs[2]* (*pDataIn);
69
70            // ynL+= ( (-B2 (Q14) * y(n-2)L (Q16) )>>16) in Q14
71            MUL32x16INTO32(pBiquadState->pDelays[3],pBiquadState->coefs[3],templ,16)
72            ynL+=templ;
73
74            // ynL+= ( (-B1 (Q14) * y(n-1)L (Q16) )>>16) in Q14
75            MUL32x16INTO32(pBiquadState->pDelays[2],pBiquadState->coefs[4],templ,16)
76            ynL+=templ;
77
78            /**************************************************************************
79                            UPDATING THE DELAYS
80            ***************************************************************************/
81            pBiquadState->pDelays[3]=pBiquadState->pDelays[2];  // y(n-2)L=y(n-1)L
82            pBiquadState->pDelays[1]=pBiquadState->pDelays[0];  // x(n-2)L=x(n-1)L
83            pBiquadState->pDelays[2]=ynL<<2;                    // Update y(n-1)L in Q16
84            pBiquadState->pDelays[0]=(*pDataIn++);              // Update x(n-1)L in Q0
85
86            /**************************************************************************
87                            WRITING THE OUTPUT
88            ***************************************************************************/
89            *pDataOut++=(LVM_INT16)(ynL>>14); // Write Left output in Q0
90
91        }
92    }
93
94