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_StereoEnhancer.h"
28 #include "VectorArithmetic.h"
29 #include "LVCS_Tables.h"
30
31 /************************************************************************************/
32 /* */
33 /* FUNCTION: LVCS_StereoEnhanceInit */
34 /* */
35 /* DESCRIPTION: */
36 /* Initialises the stereo enhancement module based on the sample rate. */
37 /* */
38 /* The function selects the coefficients for the filters and clears the data */
39 /* history. It is also used for re-initialisation when one of the system control */
40 /* parameters changes but will only change the coefficients and clear the history */
41 /* if the sample rate or speaker type has changed. */
42 /* */
43 /* PARAMETERS: */
44 /* hInstance Instance Handle */
45 /* pParams Initialisation parameters */
46 /* */
47 /* RETURNS: */
48 /* LVCS_Success Always succeeds */
49 /* */
50 /* NOTES: */
51 /* */
52 /************************************************************************************/
LVCS_SEnhancerInit(LVCS_Handle_t hInstance,LVCS_Params_t * pParams)53 LVCS_ReturnStatus_en LVCS_SEnhancerInit(LVCS_Handle_t hInstance, LVCS_Params_t* pParams) {
54 LVM_UINT16 Offset;
55 LVCS_Instance_t* pInstance = (LVCS_Instance_t*)hInstance;
56 const BiquadA012B12CoefsSP_t* pSESideCoefs;
57
58 /*
59 * If the sample rate or speaker type has changed update the filters
60 */
61 if ((pInstance->Params.SampleRate != pParams->SampleRate) ||
62 (pInstance->Params.SpeakerType != pParams->SpeakerType)) {
63 /*
64 * Set the filter coefficients based on the sample rate
65 */
66 /* Mid filter */
67 Offset = (LVM_UINT16)pParams->SampleRate;
68
69 std::array<LVM_FLOAT, android::audio_utils::kBiquadNumCoefs> coefs = {
70 LVCS_SEMidCoefTable[Offset].A0, LVCS_SEMidCoefTable[Offset].A1, 0.0,
71 LVCS_SEMidCoefTable[Offset].B1, 0.0};
72 pInstance->pSEMidBiquad.reset(
73 new android::audio_utils::BiquadFilter<LVM_FLOAT>(FCC_1, coefs));
74
75 Offset = (LVM_UINT16)(pParams->SampleRate);
76 pSESideCoefs = (BiquadA012B12CoefsSP_t*)&LVCS_SESideCoefTable[0];
77
78 /* Side filter */
79 coefs = {pSESideCoefs[Offset].A0, pSESideCoefs[Offset].A1, pSESideCoefs[Offset].A2,
80 pSESideCoefs[Offset].B1, pSESideCoefs[Offset].B2};
81 pInstance->pSESideBiquad.reset(
82 new android::audio_utils::BiquadFilter<LVM_FLOAT>(FCC_1, coefs));
83 }
84
85 return (LVCS_SUCCESS);
86 }
87 /************************************************************************************/
88 /* */
89 /* FUNCTION: LVCS_StereoEnhance */
90 /* */
91 /* DESCRIPTION: */
92 /* Enhance the stereo image in the input samples based on the following block */
93 /* diagram: */
94 /* */
95 /* ________ */
96 /* ________ | | ________ */
97 /* | | Middle | Treble | | | */
98 /* | |---------->| Boost |-------->| | */
99 /* | Stereo | |________| | M & S | */
100 /* -->| to | ________ | to |--> */
101 /* | M & S | Side | | | Stereo | */
102 /* | |---------->| Side |-------->| | */
103 /* |________| | Boost | |________| */
104 /* |________| */
105 /* */
106 /* */
107 /* If the input signal is a mono signal there will be no side signal and hence */
108 /* the side filter will not be run. In mobile speaker mode the middle filter is */
109 /* not required and the Trebble boost filter is replaced by a simple gain block. */
110 /* */
111 /* */
112 /* PARAMETERS: */
113 /* hInstance Instance Handle */
114 /* pInData Pointer to the input data */
115 /* pOutData Pointer to the output data */
116 /* NumSamples Number of samples to process */
117 /* */
118 /* RETURNS: */
119 /* LVCS_Success Always succeeds */
120 /* */
121 /* NOTES: */
122 /* 1. The side filter is not used in Mobile Speaker mode */
123 /* */
124 /************************************************************************************/
LVCS_StereoEnhancer(LVCS_Handle_t hInstance,const LVM_FLOAT * pInData,LVM_FLOAT * pOutData,LVM_UINT16 NumSamples)125 LVCS_ReturnStatus_en LVCS_StereoEnhancer(LVCS_Handle_t hInstance, const LVM_FLOAT* pInData,
126 LVM_FLOAT* pOutData, LVM_UINT16 NumSamples) {
127 LVCS_Instance_t* pInstance = (LVCS_Instance_t*)hInstance;
128 LVCS_StereoEnhancer_t* pConfig = (LVCS_StereoEnhancer_t*)&pInstance->StereoEnhancer;
129 LVM_FLOAT* pScratch;
130 pScratch = (LVM_FLOAT*)pInstance->pScratch;
131 LVM_INT32 NumChannels = pInstance->Params.NrChannels;
132 LVM_UINT16 destNumSamples = (NumChannels == FCC_1) ? NumSamples : FCC_2 * NumSamples;
133 /*
134 * Check if the Stereo Enhancer is enabled
135 */
136 if ((pInstance->Params.OperatingMode & LVCS_STEREOENHANCESWITCH) != 0) {
137 /*
138 * Convert from stereo to middle and side
139 */
140 if (NumChannels == 1) {
141 // Copy same input to scratch as Middle data
142 Copy_Float((LVM_FLOAT*)pInData, (LVM_FLOAT*)pScratch, (LVM_INT16)NumSamples);
143 } else {
144 From2iToMS_Float(pInData, pScratch, pScratch + NumSamples, (LVM_INT16)NumSamples);
145 }
146
147 /*
148 * Apply filter to the middle signal
149 */
150 if (pInstance->OutputDevice == LVCS_HEADPHONE) {
151 pInstance->pSEMidBiquad->process(pScratch, pScratch, NumSamples);
152 } else {
153 Mult3s_Float(pScratch, /* Source */
154 (LVM_FLOAT)pConfig->MidGain, /* Gain */
155 pScratch, /* Destination */
156 (LVM_INT16)NumSamples); /* Number of samples */
157 }
158
159 /*
160 * Apply the filter the side signal only in stereo mode for headphones
161 * and in all modes for mobile speakers
162 */
163 if (pInstance->Params.SourceFormat == LVCS_STEREO) {
164 pInstance->pSESideBiquad->process(pScratch + NumSamples, pScratch + NumSamples,
165 NumSamples);
166 }
167
168 if (NumChannels == 1) {
169 // Copy processed Middle data from scratch to pOutData
170 Copy_Float((LVM_FLOAT*)pScratch, (LVM_FLOAT*)pOutData, (LVM_INT16)NumSamples);
171 } else {
172 /*
173 * Convert from middle and side to stereo
174 */
175 MSTo2i_Sat_Float(pScratch, pScratch + NumSamples, pOutData, (LVM_INT16)NumSamples);
176 }
177
178 } else {
179 /*
180 * The stereo enhancer is disabled so just copy the data
181 */
182 Copy_Float((LVM_FLOAT*)pInData, /* Source */
183 (LVM_FLOAT*)pOutData, /* Destination */
184 (LVM_INT16)destNumSamples); /* Number of frames */
185 }
186
187 return (LVCS_SUCCESS);
188 }
189