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_D32F32Cll_TRC_WRA_02_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 Q30 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 37 void BP_1I_D32F32C30_TRC_WRA_02 ( Biquad_Instance_t *pInstance, 38 LVM_INT32 *pDataIn, 39 LVM_INT32 *pDataOut, 40 LVM_INT16 NrSamples) 41 { 42 LVM_INT32 ynL,templ; 43 LVM_INT16 ii; 44 PFilter_State pBiquadState = (PFilter_State) pInstance; 45 46 for (ii = NrSamples; ii != 0; ii--) 47 { 48 49 50 /************************************************************************** 51 PROCESSING OF THE LEFT CHANNEL 52 ***************************************************************************/ 53 // ynL= (A0 (Q30) * (x(n)L (Q0) - x(n-2)L (Q0) ) >>30) in Q0 54 templ=(*pDataIn)-pBiquadState->pDelays[1]; 55 MUL32x32INTO32(pBiquadState->coefs[0],templ,ynL,30) 56 57 // ynL+= ((-B2 (Q30) * y(n-2)L (Q0) ) >>30) in Q0 58 MUL32x32INTO32(pBiquadState->coefs[1],pBiquadState->pDelays[3],templ,30) 59 ynL+=templ; 60 61 // ynL+= ((-B1 (Q30) * y(n-1)L (Q0) ) >>30) in Q0 62 MUL32x32INTO32(pBiquadState->coefs[2],pBiquadState->pDelays[2],templ,30) 63 ynL+=templ; 64 65 /************************************************************************** 66 UPDATING THE DELAYS 67 ***************************************************************************/ 68 pBiquadState->pDelays[3]=pBiquadState->pDelays[2]; // y(n-2)L=y(n-1)L 69 pBiquadState->pDelays[1]=pBiquadState->pDelays[0]; // x(n-2)L=x(n-1)L 70 pBiquadState->pDelays[2]=ynL; // Update y(n-1)L in Q0 71 pBiquadState->pDelays[0]=(*pDataIn++); // Update x(n-1)L in Q0 72 73 /************************************************************************** 74 WRITING THE OUTPUT 75 ***************************************************************************/ 76 *pDataOut++=ynL; // Write Left output in Q0 77 78 } 79 80 } 81 82
