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 "FO_2I_D16F32Css_LShx_TRC_WRA_01_Private.h" 20 #include "LVM_Macros.h" 21 22 /************************************************************************** 23 ASSUMPTIONS: 24 COEFS- 25 pBiquadState->coefs[0] is A1, 26 pBiquadState->coefs[1] is A0, 27 pBiquadState->coefs[2] is -B1, these are in Q15 format 28 pBiquadState->Shift is Shift value 29 DELAYS- 30 pBiquadState->pDelays[0] is x(n-1)L in Q15 format 31 pBiquadState->pDelays[1] is y(n-1)L in Q30 format 32 pBiquadState->pDelays[2] is x(n-1)R in Q15 format 33 pBiquadState->pDelays[3] is y(n-1)R in Q30 format 34 ***************************************************************************/ 35 #ifdef BUILD_FLOAT 36 void FO_2I_D16F32C15_LShx_TRC_WRA_01(Biquad_FLOAT_Instance_t *pInstance, 37 LVM_FLOAT *pDataIn, 38 LVM_FLOAT *pDataOut, 39 LVM_INT16 NrSamples) 40 { 41 LVM_FLOAT ynL,ynR; 42 LVM_FLOAT Temp; 43 LVM_FLOAT NegSatValue; 44 LVM_INT16 ii; 45 46 PFilter_Float_State pBiquadState = (PFilter_Float_State) pInstance; 47 48 NegSatValue = -1.0f; 49 50 for (ii = NrSamples; ii != 0; ii--) 51 { 52 53 /************************************************************************** 54 PROCESSING OF THE LEFT CHANNEL 55 ***************************************************************************/ 56 57 // ynL =A1 * x(n-1)L 58 ynL = (LVM_FLOAT)pBiquadState->coefs[0] * pBiquadState->pDelays[0]; 59 // ynR =A1 * x(n-1)R 60 ynR = (LVM_FLOAT)pBiquadState->coefs[0] * pBiquadState->pDelays[2]; 61 62 63 // ynL+=A0 * x(n)L 64 ynL += (LVM_FLOAT)pBiquadState->coefs[1] * (*pDataIn); 65 // ynR+=A0 * x(n)L 66 ynR += (LVM_FLOAT)pBiquadState->coefs[1] * (*(pDataIn+1)); 67 68 69 // ynL += (-B1 * y(n-1)L ) 70 Temp = pBiquadState->pDelays[1] * pBiquadState->coefs[2]; 71 ynL += Temp; 72 // ynR += (-B1 * y(n-1)R ) ) 73 Temp = pBiquadState->pDelays[3] * pBiquadState->coefs[2]; 74 ynR += Temp; 75 76 77 /************************************************************************** 78 UPDATING THE DELAYS 79 ***************************************************************************/ 80 pBiquadState->pDelays[1] = ynL; // Update y(n-1)L 81 pBiquadState->pDelays[0] = (*pDataIn++); // Update x(n-1)L 82 83 pBiquadState->pDelays[3] = ynR; // Update y(n-1)R 84 pBiquadState->pDelays[2] = (*pDataIn++); // Update x(n-1)R 85 86 /************************************************************************** 87 WRITING THE OUTPUT 88 ***************************************************************************/ 89 90 /*Saturate results*/ 91 if(ynL > 1.0f) 92 { 93 ynL = 1.0f; 94 } 95 else 96 { 97 if(ynL < NegSatValue) 98 { 99 ynL = NegSatValue; 100 } 101 } 102 103 if(ynR > 1.0f) 104 { 105 ynR = 1.0f; 106 } 107 else 108 { 109 if(ynR < NegSatValue) 110 { 111 ynR = NegSatValue; 112 } 113 } 114 115 *pDataOut++ = (LVM_FLOAT)ynL; 116 *pDataOut++ = (LVM_FLOAT)ynR; 117 } 118 119 } 120 #else 121 void FO_2I_D16F32C15_LShx_TRC_WRA_01(Biquad_Instance_t *pInstance, 122 LVM_INT16 *pDataIn, 123 LVM_INT16 *pDataOut, 124 LVM_INT16 NrSamples) 125 { 126 LVM_INT32 ynL,ynR; 127 LVM_INT32 Temp; 128 LVM_INT32 NegSatValue; 129 LVM_INT16 ii; 130 LVM_INT16 Shift; 131 PFilter_State pBiquadState = (PFilter_State) pInstance; 132 133 NegSatValue = LVM_MAXINT_16 +1; 134 NegSatValue = -NegSatValue; 135 136 Shift = pBiquadState->Shift; 137 138 139 for (ii = NrSamples; ii != 0; ii--) 140 { 141 142 /************************************************************************** 143 PROCESSING OF THE LEFT CHANNEL 144 ***************************************************************************/ 145 146 // ynL =A1 (Q15) * x(n-1)L (Q15) in Q30 147 ynL=(LVM_INT32)pBiquadState->coefs[0]* pBiquadState->pDelays[0]; 148 // ynR =A1 (Q15) * x(n-1)R (Q15) in Q30 149 ynR=(LVM_INT32)pBiquadState->coefs[0]* pBiquadState->pDelays[2]; 150 151 152 // ynL+=A0 (Q15) * x(n)L (Q15) in Q30 153 ynL+=(LVM_INT32)pBiquadState->coefs[1]* (*pDataIn); 154 // ynR+=A0 (Q15) * x(n)L (Q15) in Q30 155 ynR+=(LVM_INT32)pBiquadState->coefs[1]* (*(pDataIn+1)); 156 157 158 // ynL += (-B1 (Q15) * y(n-1)L (Q30) ) in Q30 159 MUL32x16INTO32(pBiquadState->pDelays[1],pBiquadState->coefs[2],Temp,15); 160 ynL +=Temp; 161 // ynR += (-B1 (Q15) * y(n-1)R (Q30) ) in Q30 162 MUL32x16INTO32(pBiquadState->pDelays[3],pBiquadState->coefs[2],Temp,15); 163 ynR +=Temp; 164 165 166 /************************************************************************** 167 UPDATING THE DELAYS 168 ***************************************************************************/ 169 pBiquadState->pDelays[1]=ynL; // Update y(n-1)L in Q30 170 pBiquadState->pDelays[0]=(*pDataIn++); // Update x(n-1)L in Q15 171 172 pBiquadState->pDelays[3]=ynR; // Update y(n-1)R in Q30 173 pBiquadState->pDelays[2]=(*pDataIn++); // Update x(n-1)R in Q15 174 175 /************************************************************************** 176 WRITING THE OUTPUT 177 ***************************************************************************/ 178 /*Apply shift: Instead of left shift on 16-bit result, right shift of (15-shift) is applied 179 for better SNR*/ 180 ynL = ynL>>(15-Shift); 181 ynR = ynR>>(15-Shift); 182 183 /*Saturate results*/ 184 if(ynL > LVM_MAXINT_16) 185 { 186 ynL = LVM_MAXINT_16; 187 } 188 else 189 { 190 if(ynL < NegSatValue) 191 { 192 ynL = NegSatValue; 193 } 194 } 195 196 if(ynR > LVM_MAXINT_16) 197 { 198 ynR = LVM_MAXINT_16; 199 } 200 else 201 { 202 if(ynR < NegSatValue) 203 { 204 ynR = NegSatValue; 205 } 206 } 207 208 *pDataOut++=(LVM_INT16)ynL; 209 *pDataOut++=(LVM_INT16)ynR; 210 } 211 212 } 213 #endif 214
