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      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 Q14 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_D16F32C14_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 (Q14) * x(n-2)L (Q0) in Q14*/
     57             ynL=(LVM_INT32)pBiquadState->coefs[0]* pBiquadState->pDelays[2];
     58 
     59             /* ynL+=A1 (Q14) * x(n-1)L (Q0) in Q14*/
     60             ynL+=(LVM_INT32)pBiquadState->coefs[1]* pBiquadState->pDelays[0];
     61 
     62             /* ynL+=A0 (Q14) * x(n)L (Q0) in Q14*/
     63             ynL+=(LVM_INT32)pBiquadState->coefs[2]* (*pDataIn);
     64 
     65             /* ynL+= ( (-B2 (Q14) * y(n-2)L (Q16) )>>16) in Q14 */
     66             MUL32x16INTO32(pBiquadState->pDelays[6],pBiquadState->coefs[3],templ,16)
     67             ynL+=templ;
     68 
     69             /* ynL+=( (-B1 (Q14) * y(n-1)L (Q16) )>>16) in Q14 */
     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 (Q14) * x(n-2)R (Q0) in Q14*/
     77             ynR=(LVM_INT32)pBiquadState->coefs[0]*pBiquadState->pDelays[3];
     78 
     79             /* ynR+=A1 (Q14) * x(n-1)R (Q0) in Q14*/
     80             ynR+=(LVM_INT32)pBiquadState->coefs[1]*pBiquadState->pDelays[1];
     81 
     82             /* ynR+=A0 (Q14) * x(n)R (Q0) in Q14*/
     83             ynR+=(LVM_INT32)pBiquadState->coefs[2]*(*(pDataIn+1));
     84 
     85             /* ynR+= ( (-B2 (Q14) * y(n-2)R (Q16) )>>16) in Q14*/
     86             MUL32x16INTO32(pBiquadState->pDelays[7],pBiquadState->coefs[3],templ,16)
     87             ynR+=templ;
     88 
     89             /* ynR+=( (-B1 (Q14) * y(n-1)R (Q16) )>>16) in Q14 */
     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<<2;                    /* Update y(n-1)R in Q16*/
    101             pBiquadState->pDelays[4]=ynL<<2;                    /* 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>>14); /* Write Left output in Q0*/
    111             pDataOut++;
    112             *pDataOut=(LVM_INT16)(ynR>>14); /* Write Right ouput in Q0*/
    113             pDataOut++;
    114         }
    115 
    116     }
    117 
    118