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 "DC_2I_D16_TRC_WRA_01_Private.h"
20 #include "LVM_Macros.h"
21 
DC_2I_D16_TRC_WRA_01(Biquad_Instance_t * pInstance,LVM_INT16 * pDataIn,LVM_INT16 * pDataOut,LVM_INT16 NrSamples)22 void DC_2I_D16_TRC_WRA_01( Biquad_Instance_t       *pInstance,
23                            LVM_INT16               *pDataIn,
24                            LVM_INT16               *pDataOut,
25                            LVM_INT16               NrSamples)
26     {
27         LVM_INT32 LeftDC,RightDC;
28         LVM_INT32 Diff;
29         LVM_INT32 j;
30         PFilter_State pBiquadState = (PFilter_State) pInstance;
31 
32         LeftDC  =   pBiquadState->LeftDC;
33         RightDC =   pBiquadState->RightDC;
34         for(j=NrSamples-1;j>=0;j--)
35         {
36             /* Subtract DC an saturate */
37             Diff=*(pDataIn++)-(LeftDC>>16);
38             if (Diff > 32767) {
39                 Diff = 32767; }
40             else if (Diff < -32768) {
41                 Diff = -32768; }
42             *(pDataOut++)=(LVM_INT16)Diff;
43             if (Diff < 0) {
44                 LeftDC -= DC_D16_STEP; }
45             else {
46                 LeftDC += DC_D16_STEP; }
47 
48 
49             /* Subtract DC an saturate */
50             Diff=*(pDataIn++)-(RightDC>>16);
51             if (Diff > 32767) {
52                 Diff = 32767; }
53             else if (Diff < -32768) {
54                 Diff = -32768; }
55             *(pDataOut++)=(LVM_INT16)Diff;
56             if (Diff < 0) {
57                 RightDC -= DC_D16_STEP; }
58             else {
59                 RightDC += DC_D16_STEP; }
60 
61         }
62         pBiquadState->LeftDC    =   LeftDC;
63         pBiquadState->RightDC   =   RightDC;
64 
65 
66     }
67 
68