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_1I_D16F16Css_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 29 DELAYS- 30 pBiquadState->pDelays[0] is x(n-1)L in Q0 format 31 pBiquadState->pDelays[1] is y(n-1)L in Q0 format 32 ***************************************************************************/ 33 34 #ifdef BUILD_FLOAT 35 void FO_1I_D16F16C15_TRC_WRA_01( Biquad_FLOAT_Instance_t *pInstance, 36 LVM_FLOAT *pDataIn, 37 LVM_FLOAT *pDataOut, 38 LVM_INT16 NrSamples) 39 { 40 LVM_FLOAT ynL; 41 LVM_INT16 ii; 42 PFilter_State_FLOAT pBiquadState = (PFilter_State_FLOAT) pInstance; 43 44 for (ii = NrSamples; ii != 0; ii--) 45 { 46 47 /************************************************************************** 48 PROCESSING OF THE LEFT CHANNEL 49 ***************************************************************************/ 50 // ynL=A1 * x(n-1)L 51 ynL = (LVM_FLOAT)pBiquadState->coefs[0] * pBiquadState->pDelays[0]; 52 53 // ynL+=A0 * x(n)L 54 ynL += (LVM_FLOAT)pBiquadState->coefs[1] * (*pDataIn); 55 56 // ynL+= (-B1 * y(n-1)L 57 ynL += (LVM_FLOAT)pBiquadState->coefs[2] * pBiquadState->pDelays[1]; 58 59 /************************************************************************** 60 UPDATING THE DELAYS 61 ***************************************************************************/ 62 pBiquadState->pDelays[1] = ynL; // Update y(n-1)L 63 pBiquadState->pDelays[0] = (*pDataIn++); // Update x(n-1)L 64 65 /************************************************************************** 66 WRITING THE OUTPUT 67 ***************************************************************************/ 68 *pDataOut++ = (LVM_FLOAT)ynL; // Write Left output 69 70 } 71 72 } 73 #else 74 void FO_1I_D16F16C15_TRC_WRA_01( Biquad_Instance_t *pInstance, 75 LVM_INT16 *pDataIn, 76 LVM_INT16 *pDataOut, 77 LVM_INT16 NrSamples) 78 { 79 LVM_INT32 ynL; 80 LVM_INT16 ii; 81 PFilter_State pBiquadState = (PFilter_State) pInstance; 82 83 for (ii = NrSamples; ii != 0; ii--) 84 { 85 86 /************************************************************************** 87 PROCESSING OF THE LEFT CHANNEL 88 ***************************************************************************/ 89 // ynL=A1 (Q15) * x(n-1)L (Q0) in Q15 90 ynL=(LVM_INT32)pBiquadState->coefs[0]* pBiquadState->pDelays[0]; 91 92 // ynL+=A0 (Q15) * x(n)L (Q0) in Q15 93 ynL+=(LVM_INT32)pBiquadState->coefs[1]* (*pDataIn); 94 95 // ynL+= (-B1 (Q15) * y(n-1)L (Q0) ) in Q15 96 ynL+=(LVM_INT32)pBiquadState->coefs[2]*pBiquadState->pDelays[1]; 97 98 99 ynL=(LVM_INT16)(ynL>>15); // ynL in Q0 format 100 /************************************************************************** 101 UPDATING THE DELAYS 102 ***************************************************************************/ 103 pBiquadState->pDelays[1]=ynL; // Update y(n-1)L in Q0 104 pBiquadState->pDelays[0]=(*pDataIn++); // Update x(n-1)L in Q0 105 106 /************************************************************************** 107 WRITING THE OUTPUT 108 ***************************************************************************/ 109 *pDataOut++=(LVM_INT16)ynL; // Write Left output in Q0 110 111 } 112 113 } 114 #endif 115
