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 /* Includes */
21 /* */
22 /************************************************************************************/
23
24 #include <system/audio.h>
25 #include "LVCS.h"
26 #include "LVCS_Private.h"
27 #include "LVCS_Equaliser.h"
28 #include "BIQUAD.h"
29 #include "VectorArithmetic.h"
30 #include "LVCS_Tables.h"
31
32 /************************************************************************************/
33 /* */
34 /* FUNCTION: LVCS_EqualiserInit */
35 /* */
36 /* DESCRIPTION: */
37 /* Initialises the equaliser module */
38 /* */
39 /* The function selects the coefficients for the filters and clears the data */
40 /* history. It is also used for re-initialisation when one of the system control */
41 /* parameters changes but will only change the coefficients and clear the history */
42 /* if the sample rate or speaker type has changed. */
43 /* */
44 /* To avoid excessive testing during the sample processing the biquad type is */
45 /* set as a callback function in the init routine. */
46 /* */
47 /* PARAMETERS: */
48 /* hInstance Instance Handle */
49 /* pParams Initialisation parameters */
50 /* */
51 /* RETURNS: */
52 /* LVCS_Success Always succeeds */
53 /* */
54 /* NOTES: */
55 /* */
56 /************************************************************************************/
LVCS_EqualiserInit(LVCS_Handle_t hInstance,LVCS_Params_t * pParams)57 LVCS_ReturnStatus_en LVCS_EqualiserInit(LVCS_Handle_t hInstance, LVCS_Params_t* pParams) {
58 LVM_UINT16 Offset;
59 LVCS_Instance_t* pInstance = (LVCS_Instance_t*)hInstance;
60 const BiquadA012B12CoefsSP_t* pEqualiserCoefTable;
61
62 /*
63 * If the sample rate changes re-initialise the filters
64 */
65 if ((pInstance->Params.SampleRate != pParams->SampleRate) ||
66 (pInstance->Params.SpeakerType != pParams->SpeakerType)) {
67 /*
68 * Setup the filter coefficients and clear the history
69 */
70 Offset = (LVM_UINT16)(pParams->SampleRate + (pParams->SpeakerType * (1 + LVM_FS_48000)));
71 pEqualiserCoefTable = (BiquadA012B12CoefsSP_t*)&LVCS_EqualiserCoefTable[0];
72
73 std::array<LVM_FLOAT, android::audio_utils::kBiquadNumCoefs> coefs = {
74 pEqualiserCoefTable[Offset].A0, pEqualiserCoefTable[Offset].A1,
75 pEqualiserCoefTable[Offset].A2, pEqualiserCoefTable[Offset].B1,
76 pEqualiserCoefTable[Offset].B2};
77 pInstance->pEqBiquad.reset(new android::audio_utils::BiquadFilter<LVM_FLOAT>(
78 (pParams->NrChannels == FCC_1) ? FCC_1 : FCC_2, coefs));
79 }
80
81 return (LVCS_SUCCESS);
82 }
83 /************************************************************************************/
84 /* */
85 /* FUNCTION: LVCS_Equaliser */
86 /* */
87 /* DESCRIPTION: */
88 /* Apply the equaliser filter. */
89 /* */
90 /* PARAMETERS: */
91 /* hInstance Instance Handle */
92 /* pInputOutput Pointer to the input/output buffer */
93 /* NumSamples The number of samples to process */
94 /* */
95 /* RETURNS: */
96 /* LVCS_Success Always succeeds */
97 /* */
98 /* NOTES: */
99 /* 1. Always processes in place. */
100 /* */
101 /************************************************************************************/
LVCS_Equaliser(LVCS_Handle_t hInstance,LVM_FLOAT * pInputOutput,LVM_UINT16 NumSamples)102 LVCS_ReturnStatus_en LVCS_Equaliser(LVCS_Handle_t hInstance, LVM_FLOAT* pInputOutput,
103 LVM_UINT16 NumSamples) {
104 LVCS_Instance_t* pInstance = (LVCS_Instance_t*)hInstance;
105
106 /*
107 * Check if the equaliser is required
108 */
109 if ((pInstance->Params.OperatingMode & LVCS_EQUALISERSWITCH) != 0) {
110 /* Apply filter to the left and right channels */
111 pInstance->pEqBiquad->process(pInputOutput, pInputOutput, NumSamples);
112 }
113
114 return (LVCS_SUCCESS);
115 }
116