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 ASSUMPTIONS:
24 COEFS-
25 pBiquadState->coefs[0] is A0,
26 pBiquadState->coefs[1] is -B2,
27 pBiquadState->coefs[2] is -B1, these are in Q30 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 Q16 format
33 pBiquadState->pDelays[3] is y(n-2)L in Q16 format
34 ***************************************************************************/
BP_1I_D16F32C30_TRC_WRA_01(Biquad_FLOAT_Instance_t * pInstance,LVM_FLOAT * pDataIn,LVM_FLOAT * pDataOut,LVM_INT16 NrSamples)35 void BP_1I_D16F32C30_TRC_WRA_01 ( Biquad_FLOAT_Instance_t *pInstance,
36 LVM_FLOAT *pDataIn,
37 LVM_FLOAT *pDataOut,
38 LVM_INT16 NrSamples)
39 {
40 LVM_FLOAT ynL,templ;
41 LVM_INT16 ii;
42 PFilter_State_FLOAT pBiquadState = (PFilter_State_FLOAT)pInstance;
43
44 for (ii = NrSamples; ii != 0; ii--)
45 {
46 /**************************************************************************
47 PROCESSING OF THE LEFT CHANNEL
48 ***************************************************************************/
49 // ynL= (A0 * (x(n)L - x(n-2)L ))
50 templ = (LVM_FLOAT) *pDataIn - pBiquadState->pDelays[1];
51 ynL = pBiquadState->coefs[0] * templ;
52
53 // ynL+= ((-B2 * y(n-2)L ) )
54 templ = pBiquadState->coefs[1] * pBiquadState->pDelays[3];
55 ynL += templ;
56
57 // ynL+= ((-B1 * y(n-1)L ))
58 templ = pBiquadState->coefs[2] * pBiquadState->pDelays[2];
59 ynL += templ;
60
61 /**************************************************************************
62 UPDATING THE DELAYS
63 ***************************************************************************/
64 pBiquadState->pDelays[3] = pBiquadState->pDelays[2]; // y(n-2)L=y(n-1)L
65 pBiquadState->pDelays[1] = pBiquadState->pDelays[0]; // x(n-2)L=x(n-1)L
66 pBiquadState->pDelays[2] = ynL; // Update y(n-1)L in Q16
67 pBiquadState->pDelays[0] = (*pDataIn++); // Update x(n-1)L in Q0
68
69 /**************************************************************************
70 WRITING THE OUTPUT
71 ***************************************************************************/
72 *pDataOut++ = (ynL); // Write Left output
73 }
74 }
75