xref: /aosp_15_r20/external/libavc/common/ih264_ihadamard_scaling.c (revision 495ae853bb871d1e5a258cb02c2cc13cde8ddb9a)

/******************************************************************************
 *
 * Copyright (C) 2015 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.
 *
 *****************************************************************************
 * Originally developed and contributed by Ittiam Systems Pvt. Ltd, Bangalore
*/

/**
*******************************************************************************
* @file
*  ih264_ihadamard_scaling.c
*
* @brief
*  Contains definition of functions for h264 inverse hadamard 4x4 transform and
*  scaling
*
* @author
*  ittiam
*
* @par List of Functions:
*  - ih264_ihadamard_scaling_4x4
*  - ih264_ihadamard_scaling_2x2_uv
*
* @remarks
*  none
*
*******************************************************************************
*/

/*****************************************************************************/
/* File Includes                                                             */
/*****************************************************************************/

/* User Include Files */
#include "ih264_typedefs.h"
#include "ih264_macros.h"
#include "ih264_defs.h"
#include "ih264_trans_macros.h"
#include "ih264_trans_data.h"
#include "ih264_size_defs.h"
#include "ih264_structs.h"
#include "ih264_trans_quant_itrans_iquant.h"


/*****************************************************************************/
/* Function Definitions                                                      */
/*****************************************************************************/

/**
********************************************************************************
*
* @brief This function performs a 4x4 inverse hadamard transform on the luma
* DC coefficients and then performs scaling.
*
* @par Description:
*  The DC coefficients pass through a 2-stage inverse hadamard transform.
*  This inverse transformed content is scaled to based on Qp value.
*
* @param[in] pi2_src
*  input 4x4 block of DC coefficients
*
* @param[out] pi2_out
*  output 4x4 block
*
* @param[in] pu2_iscal_mat
*  pointer to scaling list
*
* @param[in] pu2_weigh_mat
*  pointer to weight matrix
*
* @param[in] u4_qp_div_6
*  Floor (qp/6)
*
* @param[in] pi4_tmp
*  temporary buffer of size 1*16
*
* @returns none
*
* @remarks none
*
*******************************************************************************
*/
void ih264_ihadamard_scaling_4x4(WORD16* pi2_src,
                                 WORD16* pi2_out,
                                 const UWORD16 *pu2_iscal_mat,
                                 const UWORD16 *pu2_weigh_mat,
                                 UWORD32 u4_qp_div_6,
                                 WORD32* pi4_tmp)
{
    WORD32 i;
    WORD32 x0, x1, x2, x3, x4, x5, x6, x7;
    WORD16 *pi2_src_ptr, *pi2_out_ptr;
    WORD32 *pi4_tmp_ptr;
    WORD32 rnd_fact = (u4_qp_div_6 < 6) ? (1 << (5 - u4_qp_div_6)) : 0;

    pi4_tmp_ptr = pi4_tmp;
    pi2_src_ptr = pi2_src;
    pi2_out_ptr = pi2_out;

    /* horizontal transform */
    for(i = 0; i < SUB_BLK_WIDTH_4x4; i++)
    {
        x4 = pi2_src_ptr[0];
        x5 = pi2_src_ptr[1];
        x6 = pi2_src_ptr[2];
        x7 = pi2_src_ptr[3];

        x0 = x4 + x7;
        x1 = x5 + x6;
        x2 = x5 - x6;
        x3 = x4 - x7;

        pi4_tmp_ptr[0] = x0 + x1;
        pi4_tmp_ptr[1] = x2 + x3;
        pi4_tmp_ptr[2] = x0 - x1;
        pi4_tmp_ptr[3] = x3 - x2;

        pi4_tmp_ptr += SUB_BLK_WIDTH_4x4;
        pi2_src_ptr += SUB_BLK_WIDTH_4x4;
    }

    /* vertical transform */
    pi4_tmp_ptr = pi4_tmp;
    for(i = 0; i < SUB_BLK_WIDTH_4x4; i++)
    {
        x4 = pi4_tmp_ptr[0];
        x5 = pi4_tmp_ptr[4];
        x6 = pi4_tmp_ptr[8];
        x7 = pi4_tmp_ptr[12];

        x0 = x4 + x7;
        x1 = x5 + x6;
        x2 = x5 - x6;
        x3 = x4 - x7;

        pi4_tmp_ptr[0] = x0 + x1;
        pi4_tmp_ptr[4] = x2 + x3;
        pi4_tmp_ptr[8] = x0 - x1;
        pi4_tmp_ptr[12] = x3 - x2;

        pi4_tmp_ptr++;
    }
    pi4_tmp_ptr = pi4_tmp;

    /* scaling */
    for(i = 0; i < (SUB_BLK_WIDTH_4x4 * SUB_BLK_WIDTH_4x4); i++)
    {
        INV_QUANT(pi4_tmp_ptr[i], pu2_iscal_mat[0], pu2_weigh_mat[0],
                  u4_qp_div_6, rnd_fact, 6);
        pi2_out_ptr[i] = pi4_tmp_ptr[i];
    }
}

/**
********************************************************************************
*
* @brief This function performs a 2x2 inverse hadamard transform on the chroma
* DC coefficients and then performs scaling.
*
* @par Description:
*  The DC coefficients pass through a 2-stage inverse hadamard transform.
*  This inverse transformed content is scaled to based on Qp value.
*
* @param[in] pi2_src
*  input 2x2 block of DC coefficients
*
* @param[out] pi2_out
*  output 2x2 block
*
* @param[in] pu2_iscal_mat
*  pointer to scaling list
*
* @param[in] pu2_weigh_mat
*  pointer to weight matrix
*
* @param[in] u4_qp_div_6
*  Floor (qp/6)
*
* @param[in] pi4_tmp
*  temporary buffer of size 1*16
*
* @returns none
*
* @remarks none
*
*******************************************************************************
*/
void ih264_ihadamard_scaling_2x2_uv(WORD16* pi2_src,
                                    WORD16* pi2_out,
                                    const UWORD16 *pu2_iscal_mat,
                                    const UWORD16 *pu2_weigh_mat,
                                    UWORD32 u4_qp_div_6,
                                    WORD32* pi4_tmp)
{
    WORD32 i4_x0, i4_x1, i4_x2, i4_x3, i4_x4, i4_x5, i4_x6, i4_x7;
    WORD32 i4_y0, i4_y1, i4_y2, i4_y3, i4_y4, i4_y5, i4_y6, i4_y7;

    UNUSED(pi4_tmp);

    /* U Plane */
    i4_x4 = pi2_src[0];
    i4_x5 = pi2_src[1];
    i4_x6 = pi2_src[2];
    i4_x7 = pi2_src[3];

    i4_x0 = i4_x4 + i4_x5;
    i4_x1 = i4_x4 - i4_x5;
    i4_x2 = i4_x6 + i4_x7;
    i4_x3 = i4_x6 - i4_x7;

    i4_x4 = i4_x0 + i4_x2;
    i4_x5 = i4_x1 + i4_x3;
    i4_x6 = i4_x0 - i4_x2;
    i4_x7 = i4_x1 - i4_x3;

    INV_QUANT(i4_x4, pu2_iscal_mat[0], pu2_weigh_mat[0], u4_qp_div_6, 0, 5);
    INV_QUANT(i4_x5, pu2_iscal_mat[0], pu2_weigh_mat[0], u4_qp_div_6, 0, 5);
    INV_QUANT(i4_x6, pu2_iscal_mat[0], pu2_weigh_mat[0], u4_qp_div_6, 0, 5);
    INV_QUANT(i4_x7, pu2_iscal_mat[0], pu2_weigh_mat[0], u4_qp_div_6, 0, 5);

    pi2_out[0] = i4_x4;
    pi2_out[1] = i4_x5;
    pi2_out[2] = i4_x6;
    pi2_out[3] = i4_x7;

    /* V Plane */
    i4_y4 = pi2_src[4];
    i4_y5 = pi2_src[5];
    i4_y6 = pi2_src[6];
    i4_y7 = pi2_src[7];

    i4_y0 = i4_y4 + i4_y5;
    i4_y1 = i4_y4 - i4_y5;
    i4_y2 = i4_y6 + i4_y7;
    i4_y3 = i4_y6 - i4_y7;

    i4_y4 = i4_y0 + i4_y2;
    i4_y5 = i4_y1 + i4_y3;
    i4_y6 = i4_y0 - i4_y2;
    i4_y7 = i4_y1 - i4_y3;

    INV_QUANT(i4_y4, pu2_iscal_mat[0], pu2_weigh_mat[0], u4_qp_div_6, 0, 5);
    INV_QUANT(i4_y5, pu2_iscal_mat[0], pu2_weigh_mat[0], u4_qp_div_6, 0, 5);
    INV_QUANT(i4_y6, pu2_iscal_mat[0], pu2_weigh_mat[0], u4_qp_div_6, 0, 5);
    INV_QUANT(i4_y7, pu2_iscal_mat[0], pu2_weigh_mat[0], u4_qp_div_6, 0, 5);

    pi2_out[4] = i4_y4;
    pi2_out[5] = i4_y5;
    pi2_out[6] = i4_y6;
    pi2_out[7] = i4_y7;
}