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_D16F16Css_TRC_WRA_01_Private.h"
20 #include "LVM_Macros.h"
21
22 /**************************************************************************
23 ASSUMPTIONS:
24 COEFS-
25 pBiquadState->coefs[0] is A0,
26 pBiquadState->coefs[1] is -B2,
27 pBiquadState->coefs[2] 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-2)L in Q0 format
32 pBiquadState->pDelays[2] is y(n-1)L in Q0 format
33 pBiquadState->pDelays[3] is y(n-2)L in Q0 format
34 ***************************************************************************/
BP_1I_D16F16C14_TRC_WRA_01(Biquad_FLOAT_Instance_t * pInstance,LVM_FLOAT * pDataIn,LVM_FLOAT * pDataOut,LVM_INT16 NrSamples)35 void BP_1I_D16F16C14_TRC_WRA_01 ( Biquad_FLOAT_Instance_t *pInstance,
36 LVM_FLOAT *pDataIn,
37 LVM_FLOAT *pDataOut,
38 LVM_INT16 NrSamples)
39
40 {
41 LVM_FLOAT ynL;
42 LVM_INT16 ii;
43 PFilter_State_FLOAT pBiquadState = (PFilter_State_FLOAT) pInstance;
44
45 for (ii = NrSamples; ii != 0; ii--)
46 {
47
48 /**************************************************************************
49 PROCESSING OF THE LEFT CHANNEL
50 ***************************************************************************/
51 // ynL= (A0 * (x(n)L - x(n-2)L ) )
52 ynL = pBiquadState->coefs[0] * ((*pDataIn)-pBiquadState->pDelays[1]);
53
54 // ynL+= ((-B2 * y(n-2)L ) )
55 ynL += pBiquadState->coefs[1] * pBiquadState->pDelays[3];
56
57 // ynL+= ((-B1 * y(n-1)L ) )
58 ynL += pBiquadState->coefs[2] * pBiquadState->pDelays[2];
59
60 /**************************************************************************
61 UPDATING THE DELAYS
62 ***************************************************************************/
63 pBiquadState->pDelays[3] = pBiquadState->pDelays[2]; // y(n-2)L=y(n-1)L
64 pBiquadState->pDelays[1] = pBiquadState->pDelays[0]; // x(n-2)L=x(n-1)L
65 pBiquadState->pDelays[2] = ynL; // Update y(n-1)L
66 pBiquadState->pDelays[0] = (*pDataIn++); // Update x(n-1)L
67
68 /**************************************************************************
69 WRITING THE OUTPUT
70 ***************************************************************************/
71 *pDataOut++=ynL; // Write Left output
72
73 }
74
75 }
76
77