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 "BQ_2I_D16F32Css_TRC_WRA_01_Private.h" 20 #include "LVM_Macros.h" 21 22 /************************************************************************** 23 ASSUMPTIONS: 24 COEFS- 25 pBiquadState->coefs[0] is A2, pBiquadState->coefs[1] is A1 26 pBiquadState->coefs[2] is A0, pBiquadState->coefs[3] is -B2 27 pBiquadState->coefs[4] 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 x(n-1)R in Q0 format 32 pBiquadState->pDelays[2] is x(n-2)L in Q0 format 33 pBiquadState->pDelays[3] is x(n-2)R in Q0 format 34 pBiquadState->pDelays[4] is y(n-1)L in Q16 format 35 pBiquadState->pDelays[5] is y(n-1)R in Q16 format 36 pBiquadState->pDelays[6] is y(n-2)L in Q16 format 37 pBiquadState->pDelays[7] is y(n-2)R in Q16 format 38 ***************************************************************************/ 39 40 void BQ_2I_D16F32C15_TRC_WRA_01 ( Biquad_Instance_t *pInstance, 41 LVM_INT16 *pDataIn, 42 LVM_INT16 *pDataOut, 43 LVM_INT16 NrSamples) 44 { 45 LVM_INT32 ynL,ynR,templ; 46 LVM_INT16 ii; 47 PFilter_State pBiquadState = (PFilter_State) pInstance; 48 49 for (ii = NrSamples; ii != 0; ii--) 50 { 51 52 53 /************************************************************************** 54 PROCESSING OF THE LEFT CHANNEL 55 ***************************************************************************/ 56 /* ynL=A2 (Q15) * x(n-2)L (Q0) in Q15*/ 57 ynL=(LVM_INT32)pBiquadState->coefs[0]* pBiquadState->pDelays[2]; 58 59 /* ynL+=A1 (Q15) * x(n-1)L (Q0) in Q15*/ 60 ynL+=(LVM_INT32)pBiquadState->coefs[1]* pBiquadState->pDelays[0]; 61 62 /* ynL+=A0 (Q15) * x(n)L (Q0) in Q15*/ 63 ynL+=(LVM_INT32)pBiquadState->coefs[2]* (*pDataIn); 64 65 /* ynL+= ( (-B2 (Q15) * y(n-2)L (Q16) )>>16) in Q15 */ 66 MUL32x16INTO32(pBiquadState->pDelays[6],pBiquadState->coefs[3],templ,16) 67 ynL+=templ; 68 69 /* ynL+=( (-B1 (Q15) * y(n-1)L (Q16) )>>16) in Q15 */ 70 MUL32x16INTO32(pBiquadState->pDelays[4],pBiquadState->coefs[4],templ,16) 71 ynL+=templ; 72 73 /************************************************************************** 74 PROCESSING OF THE RIGHT CHANNEL 75 ***************************************************************************/ 76 /* ynR=A2 (Q15) * x(n-2)R (Q0) in Q15*/ 77 ynR=(LVM_INT32)pBiquadState->coefs[0]*pBiquadState->pDelays[3]; 78 79 /* ynR+=A1 (Q15) * x(n-1)R (Q0) in Q15*/ 80 ynR+=(LVM_INT32)pBiquadState->coefs[1]*pBiquadState->pDelays[1]; 81 82 /* ynR+=A0 (Q15) * x(n)R (Q0) in Q15*/ 83 ynR+=(LVM_INT32)pBiquadState->coefs[2]*(*(pDataIn+1)); 84 85 /* ynR+= ( (-B2 (Q15) * y(n-2)R (Q16) )>>16) in Q15 */ 86 MUL32x16INTO32(pBiquadState->pDelays[7],pBiquadState->coefs[3],templ,16) 87 ynR+=templ; 88 89 /* ynR+=( (-B1 (Q15) * y(n-1)R (Q16) )>>16) in Q15 */ 90 MUL32x16INTO32(pBiquadState->pDelays[5],pBiquadState->coefs[4],templ,16) 91 ynR+=templ; 92 93 /************************************************************************** 94 UPDATING THE DELAYS 95 ***************************************************************************/ 96 pBiquadState->pDelays[7]=pBiquadState->pDelays[5]; /* y(n-2)R=y(n-1)R*/ 97 pBiquadState->pDelays[6]=pBiquadState->pDelays[4]; /* y(n-2)L=y(n-1)L*/ 98 pBiquadState->pDelays[3]=pBiquadState->pDelays[1]; /* x(n-2)R=x(n-1)R*/ 99 pBiquadState->pDelays[2]=pBiquadState->pDelays[0]; /* x(n-2)L=x(n-1)L*/ 100 pBiquadState->pDelays[5]=ynR<<1; /* Update y(n-1)R in Q16*/ 101 pBiquadState->pDelays[4]=ynL<<1; /* Update y(n-1)L in Q16*/ 102 pBiquadState->pDelays[0]=(*pDataIn); /* Update x(n-1)L in Q0*/ 103 pDataIn++; 104 pBiquadState->pDelays[1]=(*pDataIn); /* Update x(n-1)R in Q0*/ 105 pDataIn++; 106 107 /************************************************************************** 108 WRITING THE OUTPUT 109 ***************************************************************************/ 110 *pDataOut=(LVM_INT16)(ynL>>15); /* Write Left output in Q0*/ 111 pDataOut++; 112 *pDataOut=(LVM_INT16)(ynR>>15); /* Write Right ouput in Q0*/ 113 pDataOut++; 114 } 115 116 } 117 118
