/*
 * Copyright (C) 2004-2010 NXP Software
 * Copyright (C) 2010 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "BIQUAD.h"
#include "PK_2I_D32F32CssGss_TRC_WRA_01_Private.h"
#include "LVM_Macros.h"

/**************************************************************************
 ASSUMPTIONS:
 COEFS-
 pBiquadState->coefs[0] is A0,
 pBiquadState->coefs[1] is -B2,
 pBiquadState->coefs[2] is -B1, these are in Q14 format
 pBiquadState->coefs[3] is Gain, in Q11 format


 DELAYS-
 pBiquadState->pDelays[0] is x(n-1)L in Q0 format
 pBiquadState->pDelays[1] is x(n-1)R in Q0 format
 pBiquadState->pDelays[2] is x(n-2)L in Q0 format
 pBiquadState->pDelays[3] is x(n-2)R in Q0 format
 pBiquadState->pDelays[4] is y(n-1)L in Q0 format
 pBiquadState->pDelays[5] is y(n-1)R in Q0 format
 pBiquadState->pDelays[6] is y(n-2)L in Q0 format
 pBiquadState->pDelays[7] is y(n-2)R in Q0 format
***************************************************************************/
void PK_2I_D32F32C14G11_TRC_WRA_01 ( Biquad_Instance_t       *pInstance,
                                     LVM_INT32               *pDataIn,
                                     LVM_INT32               *pDataOut,
                                     LVM_INT16               NrSamples)
    {
        LVM_INT32 ynL,ynR,ynLO,ynRO,templ;
        LVM_INT16 ii;
        PFilter_State pBiquadState = (PFilter_State) pInstance;

         for (ii = NrSamples; ii != 0; ii--)
         {


            /**************************************************************************
                            PROCESSING OF THE LEFT CHANNEL
            ***************************************************************************/
            /* ynL= (A0 (Q14) * (x(n)L (Q0) - x(n-2)L (Q0) ) >>14)  in Q0*/
            templ=(*pDataIn)-pBiquadState->pDelays[2];
            MUL32x16INTO32(templ,pBiquadState->coefs[0],ynL,14)

            /* ynL+= ((-B2 (Q14) * y(n-2)L (Q0) ) >>14) in Q0*/
            MUL32x16INTO32(pBiquadState->pDelays[6],pBiquadState->coefs[1],templ,14)
            ynL+=templ;

            /* ynL+= ((-B1 (Q14) * y(n-1)L (Q0) ) >>14) in Q0 */
            MUL32x16INTO32(pBiquadState->pDelays[4],pBiquadState->coefs[2],templ,14)
            ynL+=templ;

            /* ynLO= ((Gain (Q11) * ynL (Q0))>>11) in Q0*/
            MUL32x16INTO32(ynL,pBiquadState->coefs[3],ynLO,11)

            /* ynLO=( ynLO(Q0) + x(n)L (Q0) ) in Q0*/
            ynLO+= (*pDataIn);

            /**************************************************************************
                            PROCESSING OF THE RIGHT CHANNEL
            ***************************************************************************/
            /* ynR= (A0 (Q14) * (x(n)R (Q0) - x(n-2)R (Q0) ) >>14)   in Q0*/
            templ=(*(pDataIn+1))-pBiquadState->pDelays[3];
            MUL32x16INTO32(templ,pBiquadState->coefs[0],ynR,14)

            /* ynR+= ((-B2 (Q14) * y(n-2)R (Q0) ) >>14)  in Q0*/
            MUL32x16INTO32(pBiquadState->pDelays[7],pBiquadState->coefs[1],templ,14)
            ynR+=templ;

            /* ynR+= ((-B1 (Q14) * y(n-1)R (Q0) ) >>14)  in Q0 */
            MUL32x16INTO32(pBiquadState->pDelays[5],pBiquadState->coefs[2],templ,14)
            ynR+=templ;

            /* ynRO= ((Gain (Q11) * ynR (Q0))>>11) in Q0*/
            MUL32x16INTO32(ynR,pBiquadState->coefs[3],ynRO,11)

            /* ynRO=( ynRO(Q0) + x(n)R (Q0) ) in Q0*/
            ynRO+= (*(pDataIn+1));

            /**************************************************************************
                            UPDATING THE DELAYS
            ***************************************************************************/
            pBiquadState->pDelays[7]=pBiquadState->pDelays[5]; /* y(n-2)R=y(n-1)R*/
            pBiquadState->pDelays[6]=pBiquadState->pDelays[4]; /* y(n-2)L=y(n-1)L*/
            pBiquadState->pDelays[3]=pBiquadState->pDelays[1]; /* x(n-2)R=x(n-1)R*/
            pBiquadState->pDelays[2]=pBiquadState->pDelays[0]; /* x(n-2)L=x(n-1)L*/
            pBiquadState->pDelays[5]=ynR; /* Update y(n-1)R in Q0*/
            pBiquadState->pDelays[4]=ynL; /* Update y(n-1)L in Q0*/
            pBiquadState->pDelays[0]=(*pDataIn); /* Update x(n-1)L in Q0*/
            pDataIn++;
            pBiquadState->pDelays[1]=(*pDataIn); /* Update x(n-1)R in Q0*/
            pDataIn++;

            /**************************************************************************
                            WRITING THE OUTPUT
            ***************************************************************************/
            *pDataOut=ynLO; /* Write Left output in Q0*/
            pDataOut++;
            *pDataOut=ynRO; /* Write Right ouput in Q0*/
            pDataOut++;

        }

    }