ST / X_NUCLEO_CCA02M1

Library to handle the X-NUCLEO-CCA02M1 MEMS Microphones Expansion Board.

Dependencies:   ST_I2S ST_FREQUENCY_DIVIDER USBDEVICE

Dependents:   HelloWorld_CCA02M1 HelloWorld_CCA02M1_mbedOS HelloWorld_CCA02M1 Karaoke_CCA01M1_CCA02M1_mbedOS

Fork of X_NUCLEO_CCA02M1 by ST Expansion SW Team

MEMS Microphones Library

Library to handle the X-NUCLEO-CCA02M1 MEMS Microphones Expansion Board. A single board allows to record a standard 2-channel stereo signal as an array of PCM samples (16 bit/sample); in principle, it could make use of six additional MEMS microphones to realize a 8-channel audio system.


Microphones configuration

Currently the configurations supported are the following:

  • Stereo@48KHz
  • Stereo@44.1KHz (CD audio quality)
  • Stereo@32KHz
  • Stereo@16KHz
  • Stereo@8KHz
  • Mono@48KHz
  • Mono@44.1KHz
  • Mono@32KHz
  • Mono@16KHz
  • Mono@8KHz

Mono configurations need a Jumper connecting PB_5 and PB_13 on the Morpho connector to properly work.


Platform compatibility

  • This board can be currently used with the Nucleo F4 Family only, please see the ST_I2S library compatibility for further information.
  • The library is compatible both with mbed OS 5.x and mbed classic 2.x (to work with mbed classic, the main application has to import the "events" library, which is not included into the "mbed" library).


I2S Peripheral Usage

By default this board makes use of the I2S peripheral available on Nucleo boards.


Acquiring through the USB

In order to acquire the recorded PCM audio channel with an audio SW on a PC, please connect the expansion board to a USB port of the PC, and the Nucleo board to a USB power supply.

Middlewares/OpenPDM2PCM/OpenPDMFilter.c@16:4ab2eac7be21, 2017-05-03 (annotated)

Committer:
davide.aliprandi@st.com
Date:
Wed May 03 18:10:29 2017 +0200
Revision:
16:4ab2eac7be21
Parent:
15:17bdadc6aa9c
Child:
20:9952bef19da1
Improving performances with LUT; keeping only default configuration with SincN = 3.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
davide.aliprandi@st.com 2:9f389fd8fb2e 1 /**
davide.aliprandi@st.com 2:9f389fd8fb2e 2 ******************************************************************************
davide.aliprandi@st.com 2:9f389fd8fb2e 3 * @file OpenPDMFilter.h
davide.aliprandi@st.com 2:9f389fd8fb2e 4 * @author CL
davide.aliprandi@st.com 2:9f389fd8fb2e 5 * @version V1.0.0
davide.aliprandi@st.com 2:9f389fd8fb2e 6 * @date 9-September-2015
davide.aliprandi@st.com 2:9f389fd8fb2e 7 * @brief Open PDM audio software decoding Library.
davide.aliprandi@st.com 2:9f389fd8fb2e 8 * This Library is used to decode and reconstruct the audio signal
davide.aliprandi@st.com 2:9f389fd8fb2e 9 * produced by ST MEMS microphone (MP45Dxxx, MP34Dxxx).
davide.aliprandi@st.com 2:9f389fd8fb2e 10 ******************************************************************************
davide.aliprandi@st.com 2:9f389fd8fb2e 11 * @attention
davide.aliprandi@st.com 2:9f389fd8fb2e 12 *
davide.aliprandi@st.com 2:9f389fd8fb2e 13 * <h2><center>&copy; COPYRIGHT 2013 STMicroelectronics</center></h2>
davide.aliprandi@st.com 2:9f389fd8fb2e 14 *
davide.aliprandi@st.com 2:9f389fd8fb2e 15 * Licensed under MCD-ST Image SW License Agreement V2, (the "License");
davide.aliprandi@st.com 2:9f389fd8fb2e 16 * You may not use this file except in compliance with the License.
davide.aliprandi@st.com 2:9f389fd8fb2e 17 * You may obtain a copy of the License at:
davide.aliprandi@st.com 2:9f389fd8fb2e 18 *
davide.aliprandi@st.com 2:9f389fd8fb2e 19 * http://www.st.com/software_license_agreement_image_v2
davide.aliprandi@st.com 2:9f389fd8fb2e 20 *
davide.aliprandi@st.com 2:9f389fd8fb2e 21 * Unless required by applicable law or agreed to in writing, software
davide.aliprandi@st.com 2:9f389fd8fb2e 22 * distributed under the License is distributed on an "AS IS" BASIS,
davide.aliprandi@st.com 2:9f389fd8fb2e 23 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
davide.aliprandi@st.com 2:9f389fd8fb2e 24 * See the License for the specific language governing permissions and
davide.aliprandi@st.com 2:9f389fd8fb2e 25 * limitations under the License.
davide.aliprandi@st.com 2:9f389fd8fb2e 26 *
davide.aliprandi@st.com 2:9f389fd8fb2e 27 ******************************************************************************
davide.aliprandi@st.com 2:9f389fd8fb2e 28 */
davide.aliprandi@st.com 2:9f389fd8fb2e 29
davide.aliprandi@st.com 2:9f389fd8fb2e 30
davide.aliprandi@st.com 2:9f389fd8fb2e 31 /* Includes ------------------------------------------------------------------*/
davide.aliprandi@st.com 2:9f389fd8fb2e 32
davide.aliprandi@st.com 2:9f389fd8fb2e 33 #include "OpenPDMFilter.h"
davide.aliprandi@st.com 2:9f389fd8fb2e 34
davide.aliprandi@st.com 2:9f389fd8fb2e 35
davide.aliprandi@st.com 2:9f389fd8fb2e 36 /* Definitions ---------------------------------------------------------------*/
davide.aliprandi@st.com 2:9f389fd8fb2e 37
davide.aliprandi@st.com 16:4ab2eac7be21 38 #define RoundDiv(a, b) (((a)>0)?(((a)+(b)/2)/(b)):(((a)-(b)/2)/(b)))
davide.aliprandi@st.com 2:9f389fd8fb2e 39 #define SaturaLH(N, L, H) (((N)<(L))?(L):(((N)>(H))?(H):(N)))
davide.aliprandi@st.com 2:9f389fd8fb2e 40
davide.aliprandi@st.com 16:4ab2eac7be21 41 #define VOLUME_MAX 64
davide.aliprandi@st.com 16:4ab2eac7be21 42 #define FILTER_GAIN 16
davide.aliprandi@st.com 16:4ab2eac7be21 43
davide.aliprandi@st.com 16:4ab2eac7be21 44 #define SINCN_MAX 3
davide.aliprandi@st.com 15:17bdadc6aa9c 45 #define DECIMATION_MAX 64
davide.aliprandi@st.com 15:17bdadc6aa9c 46
davide.aliprandi@st.com 2:9f389fd8fb2e 47
davide.aliprandi@st.com 2:9f389fd8fb2e 48 /* Variables -----------------------------------------------------------------*/
davide.aliprandi@st.com 2:9f389fd8fb2e 49
davide.aliprandi@st.com 16:4ab2eac7be21 50 uint32_t div_const = 0;
davide.aliprandi@st.com 16:4ab2eac7be21 51 int64_t sub_const = 0;
davide.aliprandi@st.com 16:4ab2eac7be21 52 uint32_t sinc[DECIMATION_MAX * SINCN_MAX];
davide.aliprandi@st.com 15:17bdadc6aa9c 53 uint32_t sinc1[DECIMATION_MAX];
davide.aliprandi@st.com 16:4ab2eac7be21 54 uint32_t sinc2[DECIMATION_MAX * 2];
davide.aliprandi@st.com 16:4ab2eac7be21 55 uint32_t coef[SINCN_MAX][DECIMATION_MAX];
davide.aliprandi@st.com 15:17bdadc6aa9c 56 #ifdef USE_LUT
davide.aliprandi@st.com 15:17bdadc6aa9c 57 int32_t lut[256][DECIMATION_MAX / 8][SINCN_MAX];
davide.aliprandi@st.com 15:17bdadc6aa9c 58 #endif
davide.aliprandi@st.com 2:9f389fd8fb2e 59
davide.aliprandi@st.com 2:9f389fd8fb2e 60
davide.aliprandi@st.com 2:9f389fd8fb2e 61 /* Functions -----------------------------------------------------------------*/
davide.aliprandi@st.com 2:9f389fd8fb2e 62
davide.aliprandi@st.com 16:4ab2eac7be21 63 int32_t filter_table(uint8_t *data, uint8_t sincn, uint8_t channels);
davide.aliprandi@st.com 2:9f389fd8fb2e 64
davide.aliprandi@st.com 2:9f389fd8fb2e 65 void convolve(uint32_t Signal[/* SignalLen */], unsigned short SignalLen,
davide.aliprandi@st.com 2:9f389fd8fb2e 66 uint32_t Kernel[/* KernelLen */], unsigned short KernelLen,
davide.aliprandi@st.com 2:9f389fd8fb2e 67 uint32_t Result[/* SignalLen + KernelLen - 1 */]);
davide.aliprandi@st.com 2:9f389fd8fb2e 68
davide.aliprandi@st.com 15:17bdadc6aa9c 69 #ifdef USE_LUT
davide.aliprandi@st.com 16:4ab2eac7be21 70 int32_t filter_table_mono(uint8_t *data, uint8_t sincn)
davide.aliprandi@st.com 16:4ab2eac7be21 71 {
davide.aliprandi@st.com 16:4ab2eac7be21 72 return (int32_t)
davide.aliprandi@st.com 16:4ab2eac7be21 73 lut[data[0]][0][sincn] +
davide.aliprandi@st.com 16:4ab2eac7be21 74 lut[data[1]][1][sincn] +
davide.aliprandi@st.com 16:4ab2eac7be21 75 lut[data[2]][2][sincn] +
davide.aliprandi@st.com 16:4ab2eac7be21 76 lut[data[3]][3][sincn] +
davide.aliprandi@st.com 16:4ab2eac7be21 77 lut[data[4]][4][sincn] +
davide.aliprandi@st.com 16:4ab2eac7be21 78 lut[data[5]][5][sincn] +
davide.aliprandi@st.com 16:4ab2eac7be21 79 lut[data[6]][6][sincn] +
davide.aliprandi@st.com 16:4ab2eac7be21 80 lut[data[7]][7][sincn];
davide.aliprandi@st.com 16:4ab2eac7be21 81 }
davide.aliprandi@st.com 16:4ab2eac7be21 82 int32_t filter_table_stereo(uint8_t *data, uint8_t sincn)
davide.aliprandi@st.com 15:17bdadc6aa9c 83 {
davide.aliprandi@st.com 16:4ab2eac7be21 84 return (int32_t)
davide.aliprandi@st.com 16:4ab2eac7be21 85 lut[data[0]][0][sincn] +
davide.aliprandi@st.com 16:4ab2eac7be21 86 lut[data[2]][1][sincn] +
davide.aliprandi@st.com 16:4ab2eac7be21 87 lut[data[4]][2][sincn] +
davide.aliprandi@st.com 16:4ab2eac7be21 88 lut[data[6]][3][sincn] +
davide.aliprandi@st.com 16:4ab2eac7be21 89 lut[data[8]][4][sincn] +
davide.aliprandi@st.com 16:4ab2eac7be21 90 lut[data[10]][5][sincn] +
davide.aliprandi@st.com 16:4ab2eac7be21 91 lut[data[12]][6][sincn] +
davide.aliprandi@st.com 16:4ab2eac7be21 92 lut[data[14]][7][sincn];
davide.aliprandi@st.com 15:17bdadc6aa9c 93 }
davide.aliprandi@st.com 16:4ab2eac7be21 94 int32_t (* filter_tables[2]) (uint8_t *data, uint8_t sincn) = {filter_table_mono, filter_table_stereo};
davide.aliprandi@st.com 15:17bdadc6aa9c 95 #else
davide.aliprandi@st.com 16:4ab2eac7be21 96 int64_t filter_table(uint8_t *data, uint8_t sincn, uint8_t channels)
davide.aliprandi@st.com 2:9f389fd8fb2e 97 {
Davidroid 13:90465220b75f 98 uint8_t c, i;
davide.aliprandi@st.com 11:b2f7f79026e4 99 uint16_t data_index = 0;
davide.aliprandi@st.com 11:b2f7f79026e4 100 uint32_t *coef_p = &coef[table][0];
davide.aliprandi@st.com 2:9f389fd8fb2e 101 int64_t F = 0;
davide.aliprandi@st.com 2:9f389fd8fb2e 102
davide.aliprandi@st.com 16:4ab2eac7be21 103 for (i = 0; i < DECIMATION_MAX; i += 8)
davide.aliprandi@st.com 15:17bdadc6aa9c 104 {
davide.aliprandi@st.com 11:b2f7f79026e4 105 c = data[data_index];
davide.aliprandi@st.com 11:b2f7f79026e4 106 F += ((c >> 7) ) * coef_p[i ] +
davide.aliprandi@st.com 11:b2f7f79026e4 107 ((c >> 6) & 0x01) * coef_p[i + 1] +
davide.aliprandi@st.com 11:b2f7f79026e4 108 ((c >> 5) & 0x01) * coef_p[i + 2] +
davide.aliprandi@st.com 11:b2f7f79026e4 109 ((c >> 4) & 0x01) * coef_p[i + 3] +
davide.aliprandi@st.com 11:b2f7f79026e4 110 ((c >> 3) & 0x01) * coef_p[i + 4] +
davide.aliprandi@st.com 11:b2f7f79026e4 111 ((c >> 2) & 0x01) * coef_p[i + 5] +
davide.aliprandi@st.com 11:b2f7f79026e4 112 ((c >> 1) & 0x01) * coef_p[i + 6] +
davide.aliprandi@st.com 11:b2f7f79026e4 113 ((c ) & 0x01) * coef_p[i + 7];
davide.aliprandi@st.com 11:b2f7f79026e4 114 data_index += channels;
davide.aliprandi@st.com 2:9f389fd8fb2e 115 }
davide.aliprandi@st.com 2:9f389fd8fb2e 116 return F;
davide.aliprandi@st.com 2:9f389fd8fb2e 117 }
davide.aliprandi@st.com 15:17bdadc6aa9c 118 #endif
davide.aliprandi@st.com 2:9f389fd8fb2e 119
davide.aliprandi@st.com 2:9f389fd8fb2e 120 void Open_PDM_Filter_Init(TPDMFilter_InitStruct *Param)
davide.aliprandi@st.com 2:9f389fd8fb2e 121 {
davide.aliprandi@st.com 16:4ab2eac7be21 122 uint16_t i, j;
davide.aliprandi@st.com 2:9f389fd8fb2e 123 int64_t sum = 0;
davide.aliprandi@st.com 16:4ab2eac7be21 124 for (i = 0; i < SINCN_MAX; i++)
davide.aliprandi@st.com 2:9f389fd8fb2e 125 {
davide.aliprandi@st.com 16:4ab2eac7be21 126 Param->Coef[i] = 0;
davide.aliprandi@st.com 16:4ab2eac7be21 127 Param->bit[i] = 0;
davide.aliprandi@st.com 2:9f389fd8fb2e 128 }
davide.aliprandi@st.com 16:4ab2eac7be21 129 for (i = 0; i < DECIMATION_MAX; i++)
davide.aliprandi@st.com 2:9f389fd8fb2e 130 {
davide.aliprandi@st.com 16:4ab2eac7be21 131 sinc1[i] = 1;
davide.aliprandi@st.com 2:9f389fd8fb2e 132 }
davide.aliprandi@st.com 16:4ab2eac7be21 133
davide.aliprandi@st.com 16:4ab2eac7be21 134 Param->OldOut = Param->OldIn = Param->OldZ = 0;
davide.aliprandi@st.com 16:4ab2eac7be21 135 Param->LP_ALFA = (Param->LP_HZ != 0 ? (uint16_t) (Param->LP_HZ * 256 / (Param->LP_HZ + Param->Fs / (2 * 3.14))) : 0);
davide.aliprandi@st.com 16:4ab2eac7be21 136 Param->HP_ALFA = (Param->HP_HZ != 0 ? (uint16_t) (Param->Fs * 256 / (2 * 3.14 * Param->HP_HZ + Param->Fs)) : 0);
davide.aliprandi@st.com 16:4ab2eac7be21 137
davide.aliprandi@st.com 16:4ab2eac7be21 138 Param->FilterLen = DECIMATION_MAX * 3;
davide.aliprandi@st.com 16:4ab2eac7be21 139 sinc[0] = 0;
davide.aliprandi@st.com 16:4ab2eac7be21 140 sinc[DECIMATION_MAX * 3 - 1] = 0;
davide.aliprandi@st.com 16:4ab2eac7be21 141 convolve(sinc1, DECIMATION_MAX, sinc1, DECIMATION_MAX, sinc2);
davide.aliprandi@st.com 16:4ab2eac7be21 142 convolve(sinc2, DECIMATION_MAX * 2 - 1, sinc1, DECIMATION_MAX, &sinc[1]);
davide.aliprandi@st.com 16:4ab2eac7be21 143 for(j = 0; j < 3; j++)
davide.aliprandi@st.com 2:9f389fd8fb2e 144 {
davide.aliprandi@st.com 16:4ab2eac7be21 145 for (i = 0; i < DECIMATION_MAX ;i++)
davide.aliprandi@st.com 2:9f389fd8fb2e 146 {
davide.aliprandi@st.com 16:4ab2eac7be21 147 coef[j][i] = sinc[j * DECIMATION_MAX + i];
davide.aliprandi@st.com 16:4ab2eac7be21 148 sum += sinc[j * DECIMATION_MAX + i];
davide.aliprandi@st.com 2:9f389fd8fb2e 149 }
davide.aliprandi@st.com 2:9f389fd8fb2e 150 }
davide.aliprandi@st.com 16:4ab2eac7be21 151
davide.aliprandi@st.com 16:4ab2eac7be21 152 sub_const = sum >> 1;
davide.aliprandi@st.com 16:4ab2eac7be21 153 div_const = sub_const * VOLUME_MAX / 32768 / FILTER_GAIN;
davide.aliprandi@st.com 16:4ab2eac7be21 154 div_const = (div_const == 0 ? 1 : div_const);
davide.aliprandi@st.com 15:17bdadc6aa9c 155
davide.aliprandi@st.com 15:17bdadc6aa9c 156 #ifdef USE_LUT
davide.aliprandi@st.com 15:17bdadc6aa9c 157 /* Look-Up Table. */
davide.aliprandi@st.com 15:17bdadc6aa9c 158 uint16_t c, d, s;
davide.aliprandi@st.com 15:17bdadc6aa9c 159 for (s = 0; s < SINCN_MAX; s++)
davide.aliprandi@st.com 15:17bdadc6aa9c 160 {
davide.aliprandi@st.com 15:17bdadc6aa9c 161 uint32_t *coef_p = &coef[s][0];
davide.aliprandi@st.com 15:17bdadc6aa9c 162 for (c = 0; c < 256; c++)
davide.aliprandi@st.com 15:17bdadc6aa9c 163 for (d = 0; d < DECIMATION_MAX / 8; d++)
davide.aliprandi@st.com 15:17bdadc6aa9c 164 lut[c][d][s] = ((c >> 7) ) * coef_p[d * 8 ] +
davide.aliprandi@st.com 15:17bdadc6aa9c 165 ((c >> 6) & 0x01) * coef_p[d * 8 + 1] +
davide.aliprandi@st.com 15:17bdadc6aa9c 166 ((c >> 5) & 0x01) * coef_p[d * 8 + 2] +
davide.aliprandi@st.com 15:17bdadc6aa9c 167 ((c >> 4) & 0x01) * coef_p[d * 8 + 3] +
davide.aliprandi@st.com 15:17bdadc6aa9c 168 ((c >> 3) & 0x01) * coef_p[d * 8 + 4] +
davide.aliprandi@st.com 15:17bdadc6aa9c 169 ((c >> 2) & 0x01) * coef_p[d * 8 + 5] +
davide.aliprandi@st.com 15:17bdadc6aa9c 170 ((c >> 1) & 0x01) * coef_p[d * 8 + 6] +
davide.aliprandi@st.com 15:17bdadc6aa9c 171 ((c ) & 0x01) * coef_p[d * 8 + 7];
davide.aliprandi@st.com 15:17bdadc6aa9c 172 }
davide.aliprandi@st.com 15:17bdadc6aa9c 173 #endif
davide.aliprandi@st.com 2:9f389fd8fb2e 174 }
davide.aliprandi@st.com 2:9f389fd8fb2e 175
davide.aliprandi@st.com 2:9f389fd8fb2e 176 void convolve(uint32_t Signal[/* SignalLen */], unsigned short SignalLen,
davide.aliprandi@st.com 2:9f389fd8fb2e 177 uint32_t Kernel[/* KernelLen */], unsigned short KernelLen,
davide.aliprandi@st.com 2:9f389fd8fb2e 178 uint32_t Result[/* SignalLen + KernelLen - 1 */])
davide.aliprandi@st.com 2:9f389fd8fb2e 179 {
davide.aliprandi@st.com 2:9f389fd8fb2e 180 uint16_t n;
davide.aliprandi@st.com 2:9f389fd8fb2e 181 for (n = 0; n < SignalLen + KernelLen - 1; n++)
davide.aliprandi@st.com 2:9f389fd8fb2e 182 {
davide.aliprandi@st.com 2:9f389fd8fb2e 183 unsigned short kmin, kmax, k;
davide.aliprandi@st.com 2:9f389fd8fb2e 184
davide.aliprandi@st.com 2:9f389fd8fb2e 185 Result[n] = 0;
davide.aliprandi@st.com 2:9f389fd8fb2e 186
davide.aliprandi@st.com 2:9f389fd8fb2e 187 kmin = (n >= KernelLen - 1) ? n - (KernelLen - 1) : 0;
davide.aliprandi@st.com 2:9f389fd8fb2e 188 kmax = (n < SignalLen - 1) ? n : SignalLen - 1;
davide.aliprandi@st.com 2:9f389fd8fb2e 189
davide.aliprandi@st.com 2:9f389fd8fb2e 190 for (k = kmin; k <= kmax; k++)
davide.aliprandi@st.com 2:9f389fd8fb2e 191 {
davide.aliprandi@st.com 2:9f389fd8fb2e 192 Result[n] += Signal[k] * Kernel[n - k];
davide.aliprandi@st.com 2:9f389fd8fb2e 193 }
davide.aliprandi@st.com 2:9f389fd8fb2e 194 }
davide.aliprandi@st.com 2:9f389fd8fb2e 195 }
davide.aliprandi@st.com 2:9f389fd8fb2e 196
davide.aliprandi@st.com 16:4ab2eac7be21 197 void Open_PDM_Filter(uint8_t* data, uint16_t* dataOut, uint16_t volume, TPDMFilter_InitStruct *Param)
davide.aliprandi@st.com 2:9f389fd8fb2e 198 {
davide.aliprandi@st.com 16:4ab2eac7be21 199 uint8_t i, data_out_index;
davide.aliprandi@st.com 16:4ab2eac7be21 200 uint8_t decimation = DECIMATION_MAX;
davide.aliprandi@st.com 16:4ab2eac7be21 201 uint8_t channels = Param->In_MicChannels;
davide.aliprandi@st.com 16:4ab2eac7be21 202 uint8_t data_inc = ((decimation >> 3) * channels);
davide.aliprandi@st.com 16:4ab2eac7be21 203 int64_t Z, Z0, Z1, Z2;
davide.aliprandi@st.com 2:9f389fd8fb2e 204 int64_t OldOut, OldIn, OldZ;
davide.aliprandi@st.com 16:4ab2eac7be21 205
davide.aliprandi@st.com 16:4ab2eac7be21 206 OldOut = Param->OldOut;
davide.aliprandi@st.com 16:4ab2eac7be21 207 OldIn = Param->OldIn;
davide.aliprandi@st.com 16:4ab2eac7be21 208 OldZ = Param->OldZ;
davide.aliprandi@st.com 16:4ab2eac7be21 209
davide.aliprandi@st.com 16:4ab2eac7be21 210 for (i = 0, data_out_index = 0; i < Param->Fs / 1000; i++, data_out_index += channels)
davide.aliprandi@st.com 2:9f389fd8fb2e 211 {
davide.aliprandi@st.com 16:4ab2eac7be21 212 #ifdef USE_LUT
davide.aliprandi@st.com 16:4ab2eac7be21 213 Z0 = filter_tables[channels - 1](data, 0);
davide.aliprandi@st.com 16:4ab2eac7be21 214 Z1 = filter_tables[channels - 1](data, 1);
davide.aliprandi@st.com 16:4ab2eac7be21 215 Z2 = filter_tables[channels - 1](data, 2);
davide.aliprandi@st.com 16:4ab2eac7be21 216 #else
davide.aliprandi@st.com 16:4ab2eac7be21 217 Z0 = filter_table(data, 0, channels);
davide.aliprandi@st.com 16:4ab2eac7be21 218 Z1 = filter_table(data, 1, channels);
davide.aliprandi@st.com 16:4ab2eac7be21 219 Z2 = filter_table(data, 2, channels);
davide.aliprandi@st.com 16:4ab2eac7be21 220 #endif
davide.aliprandi@st.com 16:4ab2eac7be21 221
davide.aliprandi@st.com 16:4ab2eac7be21 222 Z = Param->Coef[1] + Z2 - sub_const;
davide.aliprandi@st.com 16:4ab2eac7be21 223 Param->Coef[1] = Param->Coef[0] + Z1;
davide.aliprandi@st.com 16:4ab2eac7be21 224 Param->Coef[0] = Z0;
davide.aliprandi@st.com 16:4ab2eac7be21 225
davide.aliprandi@st.com 16:4ab2eac7be21 226 OldOut = (Param->HP_ALFA * (OldOut + Z - OldIn)) >> 8;
davide.aliprandi@st.com 16:4ab2eac7be21 227 OldIn = Z;
davide.aliprandi@st.com 16:4ab2eac7be21 228 Z = OldOut;
davide.aliprandi@st.com 16:4ab2eac7be21 229 OldZ = ((256 - Param->LP_ALFA) * OldZ + Param->LP_ALFA * Z) >> 8;
davide.aliprandi@st.com 16:4ab2eac7be21 230 Z = OldZ;
davide.aliprandi@st.com 16:4ab2eac7be21 231
davide.aliprandi@st.com 16:4ab2eac7be21 232 Z *= volume;
davide.aliprandi@st.com 16:4ab2eac7be21 233 Z = RoundDiv(Z, div_const);
davide.aliprandi@st.com 16:4ab2eac7be21 234 Z = SaturaLH(Z, -32700, 32700);
davide.aliprandi@st.com 16:4ab2eac7be21 235
davide.aliprandi@st.com 16:4ab2eac7be21 236 dataOut[data_out_index] = Z;
davide.aliprandi@st.com 16:4ab2eac7be21 237 data += data_inc;
davide.aliprandi@st.com 16:4ab2eac7be21 238 }
davide.aliprandi@st.com 16:4ab2eac7be21 239
davide.aliprandi@st.com 16:4ab2eac7be21 240 Param->OldOut = OldOut;
davide.aliprandi@st.com 16:4ab2eac7be21 241 Param->OldIn = OldIn;
davide.aliprandi@st.com 16:4ab2eac7be21 242 Param->OldZ = OldZ;
davide.aliprandi@st.com 2:9f389fd8fb2e 243 }