/******************************************************************************

*

* Copyright (C) 2012 Ittiam Systems Pvt Ltd, Bangalore

*

* 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.

*

******************************************************************************/

/**

 *******************************************************************************

 * @file

 *  ihevc_chroma_itrans_recon.c

 *

 * @brief

 *  Contains function definitions for inverse transform  and reconstruction

 * of chroma interleaved data.

 *

 * @author

 *  100470

 *

 * @par List of Functions:

 *  - ihevc_chroma_itrans_recon_4x4()

 *

 * @remarks

 *  None

 *

 *******************************************************************************

 */

#include <stdio.h>

#include <string.h>

#include "ihevc_typedefs.h"

#include "ihevc_macros.h"

#include "ihevc_platform_macros.h"

#include "ihevc_defs.h"

#include "ihevc_trans_tables.h"

#include "ihevc_chroma_itrans_recon.h"

#include "ihevc_trans_macros.h"

/* All the functions work one component(U or V) of interleaved data depending upon pointers passed to it */

/* Data visualization */

/* U V U V U V U V */

/* U V U V U V U V */

/* U V U V U V U V */

/* U V U V U V U V */

/* If the pointer points to first byte of above stream (U) , functions will operate on U component */

/* If the pointer points to second byte of above stream (V) , functions will operate on V component */

/**

 *******************************************************************************

 *

 * @brief

 *  This function performs Inverse transform  and reconstruction for 4x4

 * input block

 *

 * @par Description:

 *  Performs inverse transform and adds the prediction  data and clips output

 * to 8 bit

 *

 * @param[in] pi2_src

 *  Input 4x4 coefficients

 *

 * @param[in] pi2_tmp

 *  Temporary 4x4 buffer for storing inverse transform

 *  1st stage output

 *

 * @param[in] pu1_pred

 *  Prediction 4x4 block

 *

 * @param[out] pu1_dst

 *  Output 4x4 block

 *

 * @param[in] src_strd

 *  Input stride

 *

 * @param[in] pred_strd

 *  Prediction stride

 *

 * @param[in] dst_strd

 *  Output Stride

 *

 * @param[in] shift

 *  Output shift

 *

 * @param[in] zero_cols

 *  Zero columns in pi2_src

 *

 * @returns  Void

 *

 * @remarks

 *  None

 *

 *******************************************************************************

 */

void ihevc_chroma_itrans_recon_4x4(WORD16 *pi2_src,

                                   WORD16 *pi2_tmp,

                                   UWORD8 *pu1_pred,

                                   UWORD8 *pu1_dst,

                                   WORD32 src_strd,

                                   WORD32 pred_strd,

                                   WORD32 dst_strd,

                                   WORD32 zero_cols,

                                   WORD32 zero_rows)

{

    WORD32 j;

    WORD32 e[2], o[2];

    WORD32 add;

    WORD32 shift;

    WORD16 *pi2_tmp_orig;

    WORD32 trans_size;

    UNUSED(zero_rows);

    trans_size = TRANS_SIZE_4;

    pi2_tmp_orig = pi2_tmp;

    /* Inverse Transform 1st stage */

    shift = IT_SHIFT_STAGE_1;

    add = 1 << (shift - 1);

    for(j = 0; j < trans_size; j++)

    {

        /* Checking for Zero Cols */

        if((zero_cols & 1) == 1)

        {

            memset(pi2_tmp, 0, trans_size * sizeof(WORD16));

        }

        else

        {

            /* Utilizing symmetry properties to the maximum to minimize the number of multiplications */

            o[0] = g_ai2_ihevc_trans_4[1][0] * pi2_src[src_strd]

                            + g_ai2_ihevc_trans_4[3][0] * pi2_src[3 * src_strd];

            o[1] = g_ai2_ihevc_trans_4[1][1] * pi2_src[src_strd]

                            + g_ai2_ihevc_trans_4[3][1] * pi2_src[3 * src_strd];

            e[0] = g_ai2_ihevc_trans_4[0][0] * pi2_src[0]

                            + g_ai2_ihevc_trans_4[2][0] * pi2_src[2 * src_strd];

            e[1] = g_ai2_ihevc_trans_4[0][1] * pi2_src[0]

                            + g_ai2_ihevc_trans_4[2][1] * pi2_src[2 * src_strd];

            pi2_tmp[0] =

                            CLIP_S16(((e[0] + o[0] + add) >> shift));

            pi2_tmp[1] =

                            CLIP_S16(((e[1] + o[1] + add) >> shift));

            pi2_tmp[2] =

                            CLIP_S16(((e[1] - o[1] + add) >> shift));

            pi2_tmp[3] =

                            CLIP_S16(((e[0] - o[0] + add) >> shift));

        }

        pi2_src++;

        pi2_tmp += trans_size;

        zero_cols = zero_cols >> 1;

    }

    pi2_tmp = pi2_tmp_orig;

    /* Inverse Transform 2nd stage */

    shift = IT_SHIFT_STAGE_2;

    add = 1 << (shift - 1);

    for(j = 0; j < trans_size; j++)

    {

        WORD32 itrans_out;

        /* Utilizing symmetry properties to the maximum to minimize the number of multiplications */

        o[0] = g_ai2_ihevc_trans_4[1][0] * pi2_tmp[trans_size]

                        + g_ai2_ihevc_trans_4[3][0] * pi2_tmp[3 * trans_size];

        o[1] = g_ai2_ihevc_trans_4[1][1] * pi2_tmp[trans_size]

                        + g_ai2_ihevc_trans_4[3][1] * pi2_tmp[3 * trans_size];

        e[0] = g_ai2_ihevc_trans_4[0][0] * pi2_tmp[0]

                        + g_ai2_ihevc_trans_4[2][0] * pi2_tmp[2 * trans_size];

        e[1] = g_ai2_ihevc_trans_4[0][1] * pi2_tmp[0]

                        + g_ai2_ihevc_trans_4[2][1] * pi2_tmp[2 * trans_size];

        itrans_out =

                        CLIP_S16(((e[0] + o[0] + add) >> shift));

        pu1_dst[0 * 2] = CLIP_U8((itrans_out + pu1_pred[0 * 2]));

        itrans_out =

                        CLIP_S16(((e[1] + o[1] + add) >> shift));

        pu1_dst[1 * 2] = CLIP_U8((itrans_out + pu1_pred[1 * 2]));

        itrans_out =

                        CLIP_S16(((e[1] - o[1] + add) >> shift));

        pu1_dst[2 * 2] = CLIP_U8((itrans_out + pu1_pred[2 * 2]));

        itrans_out =

                        CLIP_S16(((e[0] - o[0] + add) >> shift));

        pu1_dst[3 * 2] = CLIP_U8((itrans_out + pu1_pred[3 * 2]));

        pi2_tmp++;

        pu1_pred += pred_strd;

        pu1_dst += dst_strd;

    }

}