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_D16F16Css_TRC_WRA_01_Private.h" 20 #include "LVM_Macros.h" 21 22 23 /************************************************************************** 24 ASSUMPTIONS: 25 COEFS- 26 pBiquadState->coefs[0] is A0, 27 pBiquadState->coefs[1] is -B2, 28 pBiquadState->coefs[2] is -B1, these are in Q14 format 29 30 DELAYS- 31 pBiquadState->pDelays[0] is x(n-1)L in Q0 format 32 pBiquadState->pDelays[1] is x(n-2)L in Q0 format 33 pBiquadState->pDelays[2] is y(n-1)L in Q0 format 34 pBiquadState->pDelays[3] is y(n-2)L in Q0 format 35 ***************************************************************************/ 36 #ifdef BUILD_FLOAT 37 void BP_1I_D16F16C14_TRC_WRA_01 ( Biquad_FLOAT_Instance_t *pInstance, 38 LVM_FLOAT *pDataIn, 39 LVM_FLOAT *pDataOut, 40 LVM_INT16 NrSamples) 41 42 43 { 44 LVM_FLOAT ynL; 45 LVM_INT16 ii; 46 PFilter_State_FLOAT pBiquadState = (PFilter_State_FLOAT) pInstance; 47 48 for (ii = NrSamples; ii != 0; ii--) 49 { 50 51 52 /************************************************************************** 53 PROCESSING OF THE LEFT CHANNEL 54 ***************************************************************************/ 55 // ynL= (A0 * (x(n)L - x(n-2)L ) ) 56 ynL = pBiquadState->coefs[0] * ((*pDataIn)-pBiquadState->pDelays[1]); 57 58 // ynL+= ((-B2 * y(n-2)L ) ) 59 ynL += pBiquadState->coefs[1] * pBiquadState->pDelays[3]; 60 61 // ynL+= ((-B1 * y(n-1)L ) ) 62 ynL += pBiquadState->coefs[2] * pBiquadState->pDelays[2]; 63 64 /************************************************************************** 65 UPDATING THE DELAYS 66 ***************************************************************************/ 67 pBiquadState->pDelays[3] = pBiquadState->pDelays[2]; // y(n-2)L=y(n-1)L 68 pBiquadState->pDelays[1] = pBiquadState->pDelays[0]; // x(n-2)L=x(n-1)L 69 pBiquadState->pDelays[2] = ynL; // Update y(n-1)L 70 pBiquadState->pDelays[0] = (*pDataIn++); // Update x(n-1)L 71 72 /************************************************************************** 73 WRITING THE OUTPUT 74 ***************************************************************************/ 75 *pDataOut++=ynL; // Write Left output 76 77 } 78 79 } 80 #else 81 void BP_1I_D16F16C14_TRC_WRA_01 ( Biquad_Instance_t *pInstance, 82 LVM_INT16 *pDataIn, 83 LVM_INT16 *pDataOut, 84 LVM_INT16 NrSamples) 85 86 87 { 88 LVM_INT32 ynL; 89 LVM_INT16 ii; 90 PFilter_State pBiquadState = (PFilter_State) pInstance; 91 92 for (ii = NrSamples; ii != 0; ii--) 93 { 94 95 96 /************************************************************************** 97 PROCESSING OF THE LEFT CHANNEL 98 ***************************************************************************/ 99 // ynL= (A0 (Q14) * (x(n)L (Q0) - x(n-2)L (Q0) ) ) in Q14 100 ynL=(LVM_INT32)pBiquadState->coefs[0]* ((*pDataIn)-pBiquadState->pDelays[1]); 101 102 // ynL+= ((-B2 (Q14) * y(n-2)L (Q0) ) ) in Q14 103 ynL+=(LVM_INT32)pBiquadState->coefs[1]*pBiquadState->pDelays[3]; 104 105 // ynL+= ((-B1 (Q30) * y(n-1)L (Q0) ) ) in Q14 106 ynL+=(LVM_INT32)pBiquadState->coefs[2]*pBiquadState->pDelays[2]; 107 108 ynL=(LVM_INT16)(ynL>>14); // ynL in Q0 109 /************************************************************************** 110 UPDATING THE DELAYS 111 ***************************************************************************/ 112 pBiquadState->pDelays[3]=pBiquadState->pDelays[2]; // y(n-2)L=y(n-1)L 113 pBiquadState->pDelays[1]=pBiquadState->pDelays[0]; // x(n-2)L=x(n-1)L 114 pBiquadState->pDelays[2]=ynL; // Update y(n-1)L in Q0 115 pBiquadState->pDelays[0]=(*pDataIn++); // Update x(n-1)L in Q0 116 117 /************************************************************************** 118 WRITING THE OUTPUT 119 ***************************************************************************/ 120 *pDataOut++=(LVM_INT16)ynL; // Write Left output in Q0 121 122 } 123 124 } 125 #endif 126 127
