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_D32F32Cll_TRC_WRA_01_Private.h" 20 #include "LVM_Macros.h" 21 22 23 /************************************************************************** 24 ASSUMPTIONS: 25 COEFS- 26 pBiquadState->coefs[0] is A1, 27 pBiquadState->coefs[1] is A0, 28 pBiquadState->coefs[2] is -B1, these are in Q31 format 29 30 DELAYS- 31 pBiquadState->pDelays[0] is x(n-1)L in Q0 format 32 pBiquadState->pDelays[1] is y(n-1)L in Q0 format 33 ***************************************************************************/ 34 35 void FO_1I_D32F32C31_TRC_WRA_01( Biquad_Instance_t *pInstance, 36 LVM_INT32 *pDataIn, 37 LVM_INT32 *pDataOut, 38 LVM_INT16 NrSamples) 39 { 40 LVM_INT32 ynL,templ; 41 LVM_INT16 ii; 42 PFilter_State pBiquadState = (PFilter_State) pInstance; 43 44 for (ii = NrSamples; ii != 0; ii--) 45 { 46 47 /************************************************************************** 48 PROCESSING OF THE LEFT CHANNEL 49 ***************************************************************************/ 50 // ynL=A1 (Q31) * x(n-1)L (Q0) >>31 in Q0 51 MUL32x32INTO32(pBiquadState->coefs[0],pBiquadState->pDelays[0],ynL,31) 52 53 // ynL+=A0 (Q31) * x(n)L (Q0) >> 31 in Q0 54 MUL32x32INTO32(pBiquadState->coefs[1],*pDataIn,templ,31) 55 ynL+=templ; 56 57 // ynL+= (-B1 (Q31) * y(n-1)L (Q0) ) >> 31 in Q0 58 MUL32x32INTO32(pBiquadState->coefs[2],pBiquadState->pDelays[1],templ,31) 59 ynL+=templ; 60 61 /************************************************************************** 62 UPDATING THE DELAYS 63 ***************************************************************************/ 64 pBiquadState->pDelays[1]=ynL; // Update y(n-1)L in Q0 65 pBiquadState->pDelays[0]=(*pDataIn++); // Update x(n-1)L in Q0 66 67 /************************************************************************** 68 WRITING THE OUTPUT 69 ***************************************************************************/ 70 *pDataOut++=(LVM_INT32)ynL; // Write Left output in Q0 71 } 72 73 } 74 75
