/*
 * 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.
 */

#ifndef BIQUAD_OPT
#include "BIQUAD.h"
#include "BQ_2I_D16F32Css_TRC_WRA_01_Private.h"
#include "LVM_Macros.h"

/**************************************************************************
 ASSUMPTIONS:
 COEFS-
 pBiquadState->coefs[0] is A2, pBiquadState->coefs[1] is A1
 pBiquadState->coefs[2] is A0, pBiquadState->coefs[3] is -B2
 pBiquadState->coefs[4] is -B1, these are in Q15 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 Q16 format
 pBiquadState->pDelays[5] is y(n-1)R in Q16 format
 pBiquadState->pDelays[6] is y(n-2)L in Q16 format
 pBiquadState->pDelays[7] is y(n-2)R in Q16 format
***************************************************************************/
void BQ_2I_D16F32C15_TRC_WRA_01(Biquad_FLOAT_Instance_t* pInstance, LVM_FLOAT* pDataIn,
                                LVM_FLOAT* pDataOut, LVM_INT16 NrSamples) {
    LVM_FLOAT ynL, ynR;
    LVM_INT16 ii;
    PFilter_State_FLOAT pBiquadState = (PFilter_State_FLOAT)pInstance;

    for (ii = NrSamples; ii != 0; ii--) {
        /**************************************************************************
                        PROCESSING OF THE LEFT CHANNEL
        ***************************************************************************/
        /* ynL=A2  * x(n-2)L */
        ynL = (LVM_FLOAT)pBiquadState->coefs[0] * pBiquadState->pDelays[2];

        /* ynL+=A1  * x(n-1)L */
        ynL += (LVM_FLOAT)pBiquadState->coefs[1] * pBiquadState->pDelays[0];

        /* ynL+=A0  * x(n)L */
        ynL += (LVM_FLOAT)pBiquadState->coefs[2] * (*pDataIn);

        /* ynL+= ( (-B2  * y(n-2)L )  */
        ynL += pBiquadState->pDelays[6] * pBiquadState->coefs[3];

        /* ynL+=( (-B1  * y(n-1)L  ))  */
        ynL += pBiquadState->pDelays[4] * pBiquadState->coefs[4];

        /**************************************************************************
                        PROCESSING OF THE RIGHT CHANNEL
        ***************************************************************************/
        /* ynR=A2  * x(n-2)R */
        ynR = (LVM_FLOAT)pBiquadState->coefs[0] * pBiquadState->pDelays[3];

        /* ynR+=A1  * x(n-1)R */
        ynR += (LVM_FLOAT)pBiquadState->coefs[1] * pBiquadState->pDelays[1];

        /* ynR+=A0  * x(n)R */
        ynR += (LVM_FLOAT)pBiquadState->coefs[2] * (*(pDataIn + 1));

        /* ynR+= ( (-B2  * y(n-2)R ) */
        ynR += pBiquadState->pDelays[7] * pBiquadState->coefs[3];

        /* ynR+=( (-B1  * y(n-1)R  )) in Q15 */
        ynR += pBiquadState->pDelays[5] * pBiquadState->coefs[4];

        /**************************************************************************
                        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*/
        pBiquadState->pDelays[4] = ynL;                      /* Update y(n-1)L*/
        pBiquadState->pDelays[0] = (*pDataIn);               /* Update x(n-1)L*/
        pDataIn++;
        pBiquadState->pDelays[1] = (*pDataIn); /* Update x(n-1)R*/
        pDataIn++;

        /**************************************************************************
                        WRITING THE OUTPUT
        ***************************************************************************/
        *pDataOut = (LVM_FLOAT)(ynL); /* Write Left output*/
        pDataOut++;
        *pDataOut = (LVM_FLOAT)(ynR); /* Write Right output*/
        pDataOut++;
    }
}
#endif