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 "FO_1I_D16F16Css_TRC_WRA_01_Private.h"
20 #include "LVM_Macros.h"
21
22 /**************************************************************************
23 ASSUMPTIONS:
24 COEFS-
25 pBiquadState->coefs[0] is A1,
26 pBiquadState->coefs[1] is A0,
27 pBiquadState->coefs[2] is -B1, these are in Q15 format
28
29 DELAYS-
30 pBiquadState->pDelays[0] is x(n-1)L in Q0 format
31 pBiquadState->pDelays[1] is y(n-1)L in Q0 format
32 ***************************************************************************/
33
FO_1I_D16F16C15_TRC_WRA_01(Biquad_Instance_t * pInstance,LVM_INT16 * pDataIn,LVM_INT16 * pDataOut,LVM_INT16 NrSamples)34 void FO_1I_D16F16C15_TRC_WRA_01( Biquad_Instance_t *pInstance,
35 LVM_INT16 *pDataIn,
36 LVM_INT16 *pDataOut,
37 LVM_INT16 NrSamples)
38 {
39 LVM_INT32 ynL;
40 LVM_INT16 ii;
41 PFilter_State pBiquadState = (PFilter_State) pInstance;
42
43 for (ii = NrSamples; ii != 0; ii--)
44 {
45
46 /**************************************************************************
47 PROCESSING OF THE LEFT CHANNEL
48 ***************************************************************************/
49 // ynL=A1 (Q15) * x(n-1)L (Q0) in Q15
50 ynL=(LVM_INT32)pBiquadState->coefs[0]* pBiquadState->pDelays[0];
51
52 // ynL+=A0 (Q15) * x(n)L (Q0) in Q15
53 ynL+=(LVM_INT32)pBiquadState->coefs[1]* (*pDataIn);
54
55 // ynL+= (-B1 (Q15) * y(n-1)L (Q0) ) in Q15
56 ynL+=(LVM_INT32)pBiquadState->coefs[2]*pBiquadState->pDelays[1];
57
58
59 ynL=(LVM_INT16)(ynL>>15); // ynL in Q0 format
60 /**************************************************************************
61 UPDATING THE DELAYS
62 ***************************************************************************/
63 pBiquadState->pDelays[1]=ynL; // Update y(n-1)L in Q0
64 pBiquadState->pDelays[0]=(*pDataIn++); // Update x(n-1)L in Q0
65
66 /**************************************************************************
67 WRITING THE OUTPUT
68 ***************************************************************************/
69 *pDataOut++=(LVM_INT16)ynL; // Write Left output in Q0
70
71 }
72
73 }
74
75