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

 * Copyright (C) 2013-2020 MulticoreWare, Inc

 *

 * Authors: Mandar Gurav <mandar@multicorewareinc.com>

 *          Deepthi Devaki Akkoorath <deepthidevaki@multicorewareinc.com>

 *          Mahesh Pittala <mahesh@multicorewareinc.com>

 *          Rajesh Paulraj <rajesh@multicorewareinc.com>

 *          Min Chen <min.chen@multicorewareinc.com>

 *          Praveen Kumar Tiwari <praveen@multicorewareinc.com>

 *          Nabajit Deka <nabajit@multicorewareinc.com>

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02111, USA.

 *

 * This program is also available under a commercial proprietary license.

 * For more information, contact us at license @ x265.com.

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

#include "common.h"

#include "primitives.h"

#include "contexts.h"   // costCoeffNxN_c

#include "threading.h"  // BSR

using namespace X265_NS;

#if _MSC_VER

#pragma warning(disable: 4127) // conditional expression is constant, typical for templated functions

#endif

// Fast DST Algorithm. Full matrix multiplication for DST and Fast DST algorithm

// give identical results

static void fastForwardDst(const int16_t* block, int16_t* coeff, int shift)  // input block, output coeff

{

    int c[4];

    int rnd_factor = 1 << (shift - 1);

    for (int i = 0; i < 4; i++)

    {

        // Intermediate Variables

        c[0] = block[4 * i + 0] + block[4 * i + 3];

        c[1] = block[4 * i + 1] + block[4 * i + 3];

        c[2] = block[4 * i + 0] - block[4 * i + 1];

        c[3] = 74 * block[4 * i + 2];

        coeff[i] =      (int16_t)((29 * c[0] + 55 * c[1]  + c[3] + rnd_factor) >> shift);

        coeff[4 + i] =  (int16_t)((74 * (block[4 * i + 0] + block[4 * i + 1] - block[4 * i + 3]) + rnd_factor) >> shift);

        coeff[8 + i] =  (int16_t)((29 * c[2] + 55 * c[0]  - c[3] + rnd_factor) >> shift);

        coeff[12 + i] = (int16_t)((55 * c[2] - 29 * c[1] + c[3] + rnd_factor) >> shift);

    }

}

static void inversedst(const int16_t* tmp, int16_t* block, int shift)  // input tmp, output block

{

    int i, c[4];

    int rnd_factor = 1 << (shift - 1);

    for (i = 0; i < 4; i++)

    {

        // Intermediate Variables

        c[0] = tmp[i] + tmp[8 + i];

        c[1] = tmp[8 + i] + tmp[12 + i];

        c[2] = tmp[i] - tmp[12 + i];

        c[3] = 74 * tmp[4 + i];

        block[4 * i + 0] = (int16_t)x265_clip3(-32768, 32767, (29 * c[0] + 55 * c[1]     + c[3]               + rnd_factor) >> shift);

        block[4 * i + 1] = (int16_t)x265_clip3(-32768, 32767, (55 * c[2] - 29 * c[1]     + c[3]               + rnd_factor) >> shift);

        block[4 * i + 2] = (int16_t)x265_clip3(-32768, 32767, (74 * (tmp[i] - tmp[8 + i]  + tmp[12 + i])      + rnd_factor) >> shift);

        block[4 * i + 3] = (int16_t)x265_clip3(-32768, 32767, (55 * c[0] + 29 * c[2]     - c[3]               + rnd_factor) >> shift);

    }

}

static void partialButterfly16(const int16_t* src, int16_t* dst, int shift, int line)

{

    int j, k;

    int E[8], O[8];

    int EE[4], EO[4];

    int EEE[2], EEO[2];

    int add = 1 << (shift - 1);

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

    {

        /* E and O */

        for (k = 0; k < 8; k++)

        {

            E[k] = src[k] + src[15 - k];

            O[k] = src[k] - src[15 - k];

        }

        /* EE and EO */

        for (k = 0; k < 4; k++)

        {

            EE[k] = E[k] + E[7 - k];

            EO[k] = E[k] - E[7 - k];

        }

        /* EEE and EEO */

        EEE[0] = EE[0] + EE[3];

        EEO[0] = EE[0] - EE[3];

        EEE[1] = EE[1] + EE[2];

        EEO[1] = EE[1] - EE[2];

        dst[0] = (int16_t)((g_t16[0][0] * EEE[0] + g_t16[0][1] * EEE[1] + add) >> shift);

        dst[8 * line] = (int16_t)((g_t16[8][0] * EEE[0] + g_t16[8][1] * EEE[1] + add) >> shift);

        dst[4 * line] = (int16_t)((g_t16[4][0] * EEO[0] + g_t16[4][1] * EEO[1] + add) >> shift);

        dst[12 * line] = (int16_t)((g_t16[12][0] * EEO[0] + g_t16[12][1] * EEO[1] + add) >> shift);

        for (k = 2; k < 16; k += 4)

        {

            dst[k * line] = (int16_t)((g_t16[k][0] * EO[0] + g_t16[k][1] * EO[1] + g_t16[k][2] * EO[2] +

                                       g_t16[k][3] * EO[3] + add) >> shift);

        }

        for (k = 1; k < 16; k += 2)

        {

            dst[k * line] =  (int16_t)((g_t16[k][0] * O[0] + g_t16[k][1] * O[1] + g_t16[k][2] * O[2] + g_t16[k][3] * O[3] +

                                        g_t16[k][4] * O[4] + g_t16[k][5] * O[5] + g_t16[k][6] * O[6] + g_t16[k][7] * O[7] +

                                        add) >> shift);

        }

        src += 16;

        dst++;

    }

}

static void partialButterfly32(const int16_t* src, int16_t* dst, int shift, int line)

{

    int j, k;

    int E[16], O[16];

    int EE[8], EO[8];

    int EEE[4], EEO[4];

    int EEEE[2], EEEO[2];

    int add = 1 << (shift - 1);

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

    {

        /* E and O*/

        for (k = 0; k < 16; k++)

        {

            E[k] = src[k] + src[31 - k];

            O[k] = src[k] - src[31 - k];

        }

        /* EE and EO */

        for (k = 0; k < 8; k++)

        {

            EE[k] = E[k] + E[15 - k];

            EO[k] = E[k] - E[15 - k];

        }

        /* EEE and EEO */

        for (k = 0; k < 4; k++)

        {

            EEE[k] = EE[k] + EE[7 - k];

            EEO[k] = EE[k] - EE[7 - k];

        }

        /* EEEE and EEEO */

        EEEE[0] = EEE[0] + EEE[3];

        EEEO[0] = EEE[0] - EEE[3];

        EEEE[1] = EEE[1] + EEE[2];

        EEEO[1] = EEE[1] - EEE[2];

        dst[0] = (int16_t)((g_t32[0][0] * EEEE[0] + g_t32[0][1] * EEEE[1] + add) >> shift);

        dst[16 * line] = (int16_t)((g_t32[16][0] * EEEE[0] + g_t32[16][1] * EEEE[1] + add) >> shift);

        dst[8 * line] = (int16_t)((g_t32[8][0] * EEEO[0] + g_t32[8][1] * EEEO[1] + add) >> shift);

        dst[24 * line] = (int16_t)((g_t32[24][0] * EEEO[0] + g_t32[24][1] * EEEO[1] + add) >> shift);

        for (k = 4; k < 32; k += 8)

        {

            dst[k * line] = (int16_t)((g_t32[k][0] * EEO[0] + g_t32[k][1] * EEO[1] + g_t32[k][2] * EEO[2] +

                                       g_t32[k][3] * EEO[3] + add) >> shift);

        }

        for (k = 2; k < 32; k += 4)

        {

            dst[k * line] = (int16_t)((g_t32[k][0] * EO[0] + g_t32[k][1] * EO[1] + g_t32[k][2] * EO[2] +

                                       g_t32[k][3] * EO[3] + g_t32[k][4] * EO[4] + g_t32[k][5] * EO[5] +

                                       g_t32[k][6] * EO[6] + g_t32[k][7] * EO[7] + add) >> shift);

        }

        for (k = 1; k < 32; k += 2)

        {

            dst[k * line] = (int16_t)((g_t32[k][0] * O[0] + g_t32[k][1] * O[1] + g_t32[k][2] * O[2] + g_t32[k][3] * O[3] +

                                       g_t32[k][4] * O[4] + g_t32[k][5] * O[5] + g_t32[k][6] * O[6] + g_t32[k][7] * O[7] +

                                       g_t32[k][8] * O[8] + g_t32[k][9] * O[9] + g_t32[k][10] * O[10] + g_t32[k][11] *

                                       O[11] + g_t32[k][12] * O[12] + g_t32[k][13] * O[13] + g_t32[k][14] * O[14] +

                                       g_t32[k][15] * O[15] + add) >> shift);

        }

        src += 32;

        dst++;

    }

}

static void partialButterfly8(const int16_t* src, int16_t* dst, int shift, int line)

{

    int j, k;

    int E[4], O[4];

    int EE[2], EO[2];

    int add = 1 << (shift - 1);

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

    {

        /* E and O*/

        for (k = 0; k < 4; k++)

        {

            E[k] = src[k] + src[7 - k];

            O[k] = src[k] - src[7 - k];

        }

        /* EE and EO */

        EE[0] = E[0] + E[3];

        EO[0] = E[0] - E[3];

        EE[1] = E[1] + E[2];

        EO[1] = E[1] - E[2];

        dst[0] = (int16_t)((g_t8[0][0] * EE[0] + g_t8[0][1] * EE[1] + add) >> shift);

        dst[4 * line] = (int16_t)((g_t8[4][0] * EE[0] + g_t8[4][1] * EE[1] + add) >> shift);

        dst[2 * line] = (int16_t)((g_t8[2][0] * EO[0] + g_t8[2][1] * EO[1] + add) >> shift);

        dst[6 * line] = (int16_t)((g_t8[6][0] * EO[0] + g_t8[6][1] * EO[1] + add) >> shift);

        dst[line] = (int16_t)((g_t8[1][0] * O[0] + g_t8[1][1] * O[1] + g_t8[1][2] * O[2] + g_t8[1][3] * O[3] + add) >> shift);

        dst[3 * line] = (int16_t)((g_t8[3][0] * O[0] + g_t8[3][1] * O[1] + g_t8[3][2] * O[2] + g_t8[3][3] * O[3] + add) >> shift);

        dst[5 * line] = (int16_t)((g_t8[5][0] * O[0] + g_t8[5][1] * O[1] + g_t8[5][2] * O[2] + g_t8[5][3] * O[3] + add) >> shift);

        dst[7 * line] = (int16_t)((g_t8[7][0] * O[0] + g_t8[7][1] * O[1] + g_t8[7][2] * O[2] + g_t8[7][3] * O[3] + add) >> shift);

        src += 8;

        dst++;

    }

}

static void partialButterflyInverse4(const int16_t* src, int16_t* dst, int shift, int line)

{

    int j;

    int E[2], O[2];

    int add = 1 << (shift - 1);

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

    {

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

        O[0] = g_t4[1][0] * src[line] + g_t4[3][0] * src[3 * line];

        O[1] = g_t4[1][1] * src[line] + g_t4[3][1] * src[3 * line];

        E[0] = g_t4[0][0] * src[0] + g_t4[2][0] * src[2 * line];

        E[1] = g_t4[0][1] * src[0] + g_t4[2][1] * src[2 * line];

        /* Combining even and odd terms at each hierarchy levels to calculate the final spatial domain vector */

        dst[0] = (int16_t)(x265_clip3(-32768, 32767, (E[0] + O[0] + add) >> shift));

        dst[1] = (int16_t)(x265_clip3(-32768, 32767, (E[1] + O[1] + add) >> shift));

        dst[2] = (int16_t)(x265_clip3(-32768, 32767, (E[1] - O[1] + add) >> shift));

        dst[3] = (int16_t)(x265_clip3(-32768, 32767, (E[0] - O[0] + add) >> shift));

        src++;

        dst += 4;

    }

}

static void partialButterflyInverse8(const int16_t* src, int16_t* dst, int shift, int line)

{

    int j, k;

    int E[4], O[4];

    int EE[2], EO[2];

    int add = 1 << (shift - 1);

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

    {

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

        for (k = 0; k < 4; k++)

        {

            O[k] = g_t8[1][k] * src[line] + g_t8[3][k] * src[3 * line] + g_t8[5][k] * src[5 * line] + g_t8[7][k] * src[7 * line];

        }

        EO[0] = g_t8[2][0] * src[2 * line] + g_t8[6][0] * src[6 * line];

        EO[1] = g_t8[2][1] * src[2 * line] + g_t8[6][1] * src[6 * line];

        EE[0] = g_t8[0][0] * src[0] + g_t8[4][0] * src[4 * line];

        EE[1] = g_t8[0][1] * src[0] + g_t8[4][1] * src[4 * line];

        /* Combining even and odd terms at each hierarchy levels to calculate the final spatial domain vector */

        E[0] = EE[0] + EO[0];

        E[3] = EE[0] - EO[0];

        E[1] = EE[1] + EO[1];

        E[2] = EE[1] - EO[1];

        for (k = 0; k < 4; k++)

        {

            dst[k] = (int16_t)x265_clip3(-32768, 32767, (E[k] + O[k] + add) >> shift);

            dst[k + 4] = (int16_t)x265_clip3(-32768, 32767, (E[3 - k] - O[3 - k] + add) >> shift);

        }

        src++;

        dst += 8;

    }

}

static void partialButterflyInverse16(const int16_t* src, int16_t* dst, int shift, int line)

{

    int j, k;

    int E[8], O[8];

    int EE[4], EO[4];

    int EEE[2], EEO[2];

    int add = 1 << (shift - 1);

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

    {

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

        for (k = 0; k < 8; k++)

        {

            O[k] = g_t16[1][k] * src[line] + g_t16[3][k] * src[3 * line] + g_t16[5][k] * src[5 * line] + g_t16[7][k] * src[7 * line] +

                g_t16[9][k] * src[9 * line] + g_t16[11][k] * src[11 * line] + g_t16[13][k] * src[13 * line] + g_t16[15][k] * src[15 * line];

        }

        for (k = 0; k < 4; k++)

        {

            EO[k] = g_t16[2][k] * src[2 * line] + g_t16[6][k] * src[6 * line] + g_t16[10][k] * src[10 * line] + g_t16[14][k] * src[14 * line];

        }

        EEO[0] = g_t16[4][0] * src[4 * line] + g_t16[12][0] * src[12 * line];

        EEE[0] = g_t16[0][0] * src[0] + g_t16[8][0] * src[8 * line];

        EEO[1] = g_t16[4][1] * src[4 * line] + g_t16[12][1] * src[12 * line];

        EEE[1] = g_t16[0][1] * src[0] + g_t16[8][1] * src[8 * line];

        /* Combining even and odd terms at each hierarchy levels to calculate the final spatial domain vector */

        for (k = 0; k < 2; k++)

        {

            EE[k] = EEE[k] + EEO[k];

            EE[k + 2] = EEE[1 - k] - EEO[1 - k];

        }

        for (k = 0; k < 4; k++)

        {

            E[k] = EE[k] + EO[k];

            E[k + 4] = EE[3 - k] - EO[3 - k];

        }

        for (k = 0; k < 8; k++)

        {

            dst[k]   = (int16_t)x265_clip3(-32768, 32767, (E[k] + O[k] + add) >> shift);

            dst[k + 8] = (int16_t)x265_clip3(-32768, 32767, (E[7 - k] - O[7 - k] + add) >> shift);

        }

        src++;

        dst += 16;

    }

}

static void partialButterflyInverse32(const int16_t* src, int16_t* dst, int shift, int line)

{

    int j, k;

    int E[16], O[16];

    int EE[8], EO[8];

    int EEE[4], EEO[4];

    int EEEE[2], EEEO[2];

    int add = 1 << (shift - 1);

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

    {

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

        for (k = 0; k < 16; k++)

        {

            O[k] = g_t32[1][k] * src[line] + g_t32[3][k] * src[3 * line] + g_t32[5][k] * src[5 * line] + g_t32[7][k] * src[7 * line] +

                g_t32[9][k] * src[9 * line] + g_t32[11][k] * src[11 * line] + g_t32[13][k] * src[13 * line] + g_t32[15][k] * src[15 * line] +

                g_t32[17][k] * src[17 * line] + g_t32[19][k] * src[19 * line] + g_t32[21][k] * src[21 * line] + g_t32[23][k] * src[23 * line] +

                g_t32[25][k] * src[25 * line] + g_t32[27][k] * src[27 * line] + g_t32[29][k] * src[29 * line] + g_t32[31][k] * src[31 * line];

        }

        for (k = 0; k < 8; k++)

        {

            EO[k] = g_t32[2][k] * src[2 * line] + g_t32[6][k] * src[6 * line] + g_t32[10][k] * src[10 * line] + g_t32[14][k] * src[14 * line] +

                g_t32[18][k] * src[18 * line] + g_t32[22][k] * src[22 * line] + g_t32[26][k] * src[26 * line] + g_t32[30][k] * src[30 * line];

        }

        for (k = 0; k < 4; k++)

        {

            EEO[k] = g_t32[4][k] * src[4 * line] + g_t32[12][k] * src[12 * line] + g_t32[20][k] * src[20 * line] + g_t32[28][k] * src[28 * line];

        }

        EEEO[0] = g_t32[8][0] * src[8 * line] + g_t32[24][0] * src[24 * line];

        EEEO[1] = g_t32[8][1] * src[8 * line] + g_t32[24][1] * src[24 * line];

        EEEE[0] = g_t32[0][0] * src[0] + g_t32[16][0] * src[16 * line];

        EEEE[1] = g_t32[0][1] * src[0] + g_t32[16][1] * src[16 * line];

        /* Combining even and odd terms at each hierarchy levels to calculate the final spatial domain vector */

        EEE[0] = EEEE[0] + EEEO[0];

        EEE[3] = EEEE[0] - EEEO[0];

        EEE[1] = EEEE[1] + EEEO[1];

        EEE[2] = EEEE[1] - EEEO[1];

        for (k = 0; k < 4; k++)

        {

            EE[k] = EEE[k] + EEO[k];

            EE[k + 4] = EEE[3 - k] - EEO[3 - k];

        }

        for (k = 0; k < 8; k++)

        {

            E[k] = EE[k] + EO[k];

            E[k + 8] = EE[7 - k] - EO[7 - k];

        }

        for (k = 0; k < 16; k++)

        {

            dst[k] = (int16_t)x265_clip3(-32768, 32767, (E[k] + O[k] + add) >> shift);

            dst[k + 16] = (int16_t)x265_clip3(-32768, 32767, (E[15 - k] - O[15 - k] + add) >> shift);

        }

        src++;

        dst += 32;

    }

}

static void partialButterfly4(const int16_t* src, int16_t* dst, int shift, int line)

{

    int j;

    int E[2], O[2];

    int add = 1 << (shift - 1);

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

    {

        /* E and O */

        E[0] = src[0] + src[3];

        O[0] = src[0] - src[3];

        E[1] = src[1] + src[2];

        O[1] = src[1] - src[2];

        dst[0] = (int16_t)((g_t4[0][0] * E[0] + g_t4[0][1] * E[1] + add) >> shift);

        dst[2 * line] = (int16_t)((g_t4[2][0] * E[0] + g_t4[2][1] * E[1] + add) >> shift);

        dst[line] = (int16_t)((g_t4[1][0] * O[0] + g_t4[1][1] * O[1] + add) >> shift);

        dst[3 * line] = (int16_t)((g_t4[3][0] * O[0] + g_t4[3][1] * O[1] + add) >> shift);

        src += 4;

        dst++;

    }

}

namespace X265_NS {

void dst4_c(const int16_t* src, int16_t* dst, intptr_t srcStride)

{

    const int shift_1st = 1 + X265_DEPTH - 8;

    const int shift_2nd = 8;

    ALIGN_VAR_32(int16_t, coef[4 * 4]);

    ALIGN_VAR_32(int16_t, block[4 * 4]);

    for (int i = 0; i < 4; i++)

    {

        memcpy(&block[i * 4], &src[i * srcStride], 4 * sizeof(int16_t));

    }

    fastForwardDst(block, coef, shift_1st);

    fastForwardDst(coef, dst, shift_2nd);

}

void dct4_c(const int16_t* src, int16_t* dst, intptr_t srcStride)

{

    const int shift_1st = 1 + X265_DEPTH - 8;

    const int shift_2nd = 8;

    ALIGN_VAR_32(int16_t, coef[4 * 4]);

    ALIGN_VAR_32(int16_t, block[4 * 4]);

    for (int i = 0; i < 4; i++)

    {

        memcpy(&block[i * 4], &src[i * srcStride], 4 * sizeof(int16_t));

    }

    partialButterfly4(block, coef, shift_1st, 4);

    partialButterfly4(coef, dst, shift_2nd, 4);

}

void dct8_c(const int16_t* src, int16_t* dst, intptr_t srcStride)

{

    const int shift_1st = 2 + X265_DEPTH - 8;

    const int shift_2nd = 9;

    ALIGN_VAR_32(int16_t, coef[8 * 8]);

    ALIGN_VAR_32(int16_t, block[8 * 8]);

    for (int i = 0; i < 8; i++)

    {

        memcpy(&block[i * 8], &src[i * srcStride], 8 * sizeof(int16_t));

    }

    partialButterfly8(block, coef, shift_1st, 8);

    partialButterfly8(coef, dst, shift_2nd, 8);

}

void dct16_c(const int16_t* src, int16_t* dst, intptr_t srcStride)

{

    const int shift_1st = 3 + X265_DEPTH - 8;

    const int shift_2nd = 10;

    ALIGN_VAR_32(int16_t, coef[16 * 16]);

    ALIGN_VAR_32(int16_t, block[16 * 16]);

    for (int i = 0; i < 16; i++)

    {

        memcpy(&block[i * 16], &src[i * srcStride], 16 * sizeof(int16_t));

    }

    partialButterfly16(block, coef, shift_1st, 16);

    partialButterfly16(coef, dst, shift_2nd, 16);

}

void dct32_c(const int16_t* src, int16_t* dst, intptr_t srcStride)

{

    const int shift_1st = 4 + X265_DEPTH - 8;

    const int shift_2nd = 11;

    ALIGN_VAR_32(int16_t, coef[32 * 32]);

    ALIGN_VAR_32(int16_t, block[32 * 32]);

    for (int i = 0; i < 32; i++)

    {

        memcpy(&block[i * 32], &src[i * srcStride], 32 * sizeof(int16_t));

    }

    partialButterfly32(block, coef, shift_1st, 32);

    partialButterfly32(coef, dst, shift_2nd, 32);

}

void idst4_c(const int16_t* src, int16_t* dst, intptr_t dstStride)

{

    const int shift_1st = 7;

    const int shift_2nd = 12 - (X265_DEPTH - 8);

    ALIGN_VAR_32(int16_t, coef[4 * 4]);

    ALIGN_VAR_32(int16_t, block[4 * 4]);

    inversedst(src, coef, shift_1st); // Forward DST BY FAST ALGORITHM, block input, coef output

    inversedst(coef, block, shift_2nd); // Forward DST BY FAST ALGORITHM, coef input, coeff output

    for (int i = 0; i < 4; i++)

    {

        memcpy(&dst[i * dstStride], &block[i * 4], 4 * sizeof(int16_t));

    }

}

void idct4_c(const int16_t* src, int16_t* dst, intptr_t dstStride)

{

    const int shift_1st = 7;

    const int shift_2nd = 12 - (X265_DEPTH - 8);

    ALIGN_VAR_32(int16_t, coef[4 * 4]);

    ALIGN_VAR_32(int16_t, block[4 * 4]);

    partialButterflyInverse4(src, coef, shift_1st, 4); // Forward DST BY FAST ALGORITHM, block input, coef output

    partialButterflyInverse4(coef, block, shift_2nd, 4); // Forward DST BY FAST ALGORITHM, coef input, coeff output

    for (int i = 0; i < 4; i++)

    {

        memcpy(&dst[i * dstStride], &block[i * 4], 4 * sizeof(int16_t));

    }

}

void idct8_c(const int16_t* src, int16_t* dst, intptr_t dstStride)

{

    const int shift_1st = 7;

    const int shift_2nd = 12 - (X265_DEPTH - 8);

    ALIGN_VAR_32(int16_t, coef[8 * 8]);

    ALIGN_VAR_32(int16_t, block[8 * 8]);

    partialButterflyInverse8(src, coef, shift_1st, 8);

    partialButterflyInverse8(coef, block, shift_2nd, 8);

    for (int i = 0; i < 8; i++)

    {

        memcpy(&dst[i * dstStride], &block[i * 8], 8 * sizeof(int16_t));

    }

}

void idct16_c(const int16_t* src, int16_t* dst, intptr_t dstStride)

{

    const int shift_1st = 7;

    const int shift_2nd = 12 - (X265_DEPTH - 8);

    ALIGN_VAR_32(int16_t, coef[16 * 16]);

    ALIGN_VAR_32(int16_t, block[16 * 16]);

    partialButterflyInverse16(src, coef, shift_1st, 16);

    partialButterflyInverse16(coef, block, shift_2nd, 16);

    for (int i = 0; i < 16; i++)

    {

        memcpy(&dst[i * dstStride], &block[i * 16], 16 * sizeof(int16_t));

    }

}

void idct32_c(const int16_t* src, int16_t* dst, intptr_t dstStride)

{

    const int shift_1st = 7;

    const int shift_2nd = 12 - (X265_DEPTH - 8);

    ALIGN_VAR_32(int16_t, coef[32 * 32]);

    ALIGN_VAR_32(int16_t, block[32 * 32]);

    partialButterflyInverse32(src, coef, shift_1st, 32);

    partialButterflyInverse32(coef, block, shift_2nd, 32);

    for (int i = 0; i < 32; i++)

    {

        memcpy(&dst[i * dstStride], &block[i * 32], 32 * sizeof(int16_t));

    }

}

} // namespace X265_NS

static void dequant_normal_c(const int16_t* quantCoef, int16_t* coef, int num, int scale, int shift)

{

#if HIGH_BIT_DEPTH

    X265_CHECK(scale < 32768 || ((scale & 3) == 0 && shift > (X265_DEPTH - 8)), "dequant invalid scale %d\n", scale);

#else

    // NOTE: maximum of scale is (72 * 256)

    X265_CHECK(scale < 32768, "dequant invalid scale %d\n", scale);

#endif

    X265_CHECK(num <= 32 * 32, "dequant num %d too large\n", num);

    X265_CHECK((num % 8) == 0, "dequant num %d not multiple of 8\n", num);

    X265_CHECK(shift <= 10, "shift too large %d\n", shift);

    X265_CHECK(((intptr_t)coef & 31) == 0, "dequant coef buffer not aligned\n");

    int add, coeffQ;

    add = 1 << (shift - 1);

    for (int n = 0; n < num; n++)

    {

        coeffQ = (quantCoef[n] * scale + add) >> shift;

        coef[n] = (int16_t)x265_clip3(-32768, 32767, coeffQ);

    }

}

static void dequant_scaling_c(const int16_t* quantCoef, const int32_t* deQuantCoef, int16_t* coef, int num, int per, int shift)

{

    X265_CHECK(num <= 32 * 32, "dequant num %d too large\n", num);

    int add, coeffQ;

    shift += 4;

    if (shift > per)

    {

        add = 1 << (shift - per - 1);

        for (int n = 0; n < num; n++)

        {

            coeffQ = ((quantCoef[n] * deQuantCoef[n]) + add) >> (shift - per);

            coef[n] = (int16_t)x265_clip3(-32768, 32767, coeffQ);

        }

    }

    else

    {

        for (int n = 0; n < num; n++)

        {

            coeffQ   = x265_clip3(-32768, 32767, quantCoef[n] * deQuantCoef[n]);

            coef[n] = (int16_t)x265_clip3(-32768, 32767, coeffQ << (per - shift));

        }

    }

}

static uint32_t quant_c(const int16_t* coef, const int32_t* quantCoeff, int32_t* deltaU, int16_t* qCoef, int qBits, int add, int numCoeff)

{

    X265_CHECK(qBits >= 8, "qBits less than 8\n");

    X265_CHECK((numCoeff % 16) == 0, "numCoeff must be multiple of 16\n");

    int qBits8 = qBits - 8;

    uint32_t numSig = 0;

    for (int blockpos = 0; blockpos < numCoeff; blockpos++)

    {

        int level = coef[blockpos];

        int sign  = (level < 0 ? -1 : 1);

        int tmplevel = abs(level) * quantCoeff[blockpos];

        level = ((tmplevel + add) >> qBits);

        deltaU[blockpos] = ((tmplevel - (level << qBits)) >> qBits8);

        if (level)

            ++numSig;

        level *= sign;

        qCoef[blockpos] = (int16_t)x265_clip3(-32768, 32767, level);

    }

    return numSig;

}

static uint32_t nquant_c(const int16_t* coef, const int32_t* quantCoeff, int16_t* qCoef, int qBits, int add, int numCoeff)

{

    X265_CHECK((numCoeff % 16) == 0, "number of quant coeff is not multiple of 4x4\n");

    X265_CHECK((uint32_t)add < ((uint32_t)1 << qBits), "2 ^ qBits less than add\n");

    X265_CHECK(((intptr_t)quantCoeff & 31) == 0, "quantCoeff buffer not aligned\n");

    uint32_t numSig = 0;

    for (int blockpos = 0; blockpos < numCoeff; blockpos++)

    {

        int level = coef[blockpos];

        int sign  = (level < 0 ? -1 : 1);

        int tmplevel = abs(level) * quantCoeff[blockpos];

        level = ((tmplevel + add) >> qBits);

        if (level)

            ++numSig;

        level *= sign;

        // TODO: when we limit range to [-32767, 32767], we can get more performance with output change

        //       But nquant is a little percent in rdoQuant, so I keep old dynamic range for compatible

        qCoef[blockpos] = (int16_t)abs(x265_clip3(-32768, 32767, level));

    }

    return numSig;

}

template<int trSize>

int  count_nonzero_c(const int16_t* quantCoeff)

{

    X265_CHECK(((intptr_t)quantCoeff & 15) == 0, "quant buffer not aligned\n");

    int count = 0;

    int numCoeff = trSize * trSize;

    for (int i = 0; i < numCoeff; i++)

    {

        count += quantCoeff[i] != 0;

    }

    return count;

}

Unexecuted instantiation: int count_nonzero_c<4>(short const*)

Unexecuted instantiation: int count_nonzero_c<8>(short const*)

Unexecuted instantiation: int count_nonzero_c<16>(short const*)

Unexecuted instantiation: int count_nonzero_c<32>(short const*)

template<int trSize>

uint32_t copy_count(int16_t* coeff, const int16_t* residual, intptr_t resiStride)

{

    uint32_t numSig = 0;

    for (int k = 0; k < trSize; k++)

    {

        for (int j = 0; j < trSize; j++)

        {

            coeff[k * trSize + j] = residual[k * resiStride + j];

            numSig += (residual[k * resiStride + j] != 0);

        }

    }

    return numSig;

}

Unexecuted instantiation: unsigned int copy_count<4>(short*, short const*, long)

Unexecuted instantiation: unsigned int copy_count<8>(short*, short const*, long)

Unexecuted instantiation: unsigned int copy_count<16>(short*, short const*, long)

Unexecuted instantiation: unsigned int copy_count<32>(short*, short const*, long)

static void denoiseDct_c(int16_t* dctCoef, uint32_t* resSum, const uint16_t* offset, int numCoeff)

{

    for (int i = 0; i < numCoeff; i++)

    {

        int level = dctCoef[i];

        int sign = level >> 31;

        level = (level + sign) ^ sign;

        resSum[i] += level;

        level -= offset[i];

        dctCoef[i] = (int16_t)(level < 0 ? 0 : (level ^ sign) - sign);

    }

}

static int scanPosLast_c(const uint16_t *scan, const coeff_t *coeff, uint16_t *coeffSign, uint16_t *coeffFlag, uint8_t *coeffNum, int numSig, const uint16_t* /*scanCG4x4*/, const int /*trSize*/)

{

    memset(coeffNum, 0, MLS_GRP_NUM * sizeof(*coeffNum));

    memset(coeffFlag, 0, MLS_GRP_NUM * sizeof(*coeffFlag));

    memset(coeffSign, 0, MLS_GRP_NUM * sizeof(*coeffSign));

    int scanPosLast = 0;

    do

    {

        const uint32_t cgIdx = (uint32_t)scanPosLast >> MLS_CG_SIZE;

        const uint32_t posLast = scan[scanPosLast++];

        const int curCoeff = coeff[posLast];

        const uint32_t isNZCoeff = (curCoeff != 0);

        // get L1 sig map

        // NOTE: the new algorithm is complicated, so I keep reference code here

        //uint32_t posy   = posLast >> log2TrSize;

        //uint32_t posx   = posLast - (posy << log2TrSize);

        //uint32_t blkIdx0 = ((posy >> MLS_CG_LOG2_SIZE) << codingParameters.log2TrSizeCG) + (posx >> MLS_CG_LOG2_SIZE);

        //const uint32_t blkIdx = ((posLast >> (2 * MLS_CG_LOG2_SIZE)) & ~maskPosXY) + ((posLast >> MLS_CG_LOG2_SIZE) & maskPosXY);

        //sigCoeffGroupFlag64 |= ((uint64_t)isNZCoeff << blkIdx);

        numSig -= isNZCoeff;

        // TODO: optimize by instruction BTS

        coeffSign[cgIdx] += (uint16_t)(((uint32_t)curCoeff >> 31) << coeffNum[cgIdx]);

        coeffFlag[cgIdx] = (coeffFlag[cgIdx] << 1) + (uint16_t)isNZCoeff;

        coeffNum[cgIdx] += (uint8_t)isNZCoeff;

    }

    while (numSig > 0);

    return scanPosLast - 1;

}

// NOTE: no defined value on lastNZPosInCG & absSumSign when ALL ZEROS block as input

static uint32_t findPosFirstLast_c(const int16_t *dstCoeff, const intptr_t trSize, const uint16_t scanTbl[16])

{

    int n;

    for (n = SCAN_SET_SIZE - 1; n >= 0; n--)

    {

        const uint32_t idx = scanTbl[n];

        const uint32_t idxY = idx / MLS_CG_SIZE;

        const uint32_t idxX = idx % MLS_CG_SIZE;

        if (dstCoeff[idxY * trSize + idxX])

            break;

    }

    X265_CHECK(n >= -1, "non-zero coeff scan failuare!\n");

    uint32_t lastNZPosInCG = (uint32_t)n;

    for (n = 0; n < SCAN_SET_SIZE; n++)

    {

        const uint32_t idx = scanTbl[n];

        const uint32_t idxY = idx / MLS_CG_SIZE;

        const uint32_t idxX = idx % MLS_CG_SIZE;

        if (dstCoeff[idxY * trSize + idxX])

            break;

    }

    uint32_t firstNZPosInCG = (uint32_t)n;

    uint32_t absSumSign = 0;

    for (n = firstNZPosInCG; n <= (int)lastNZPosInCG; n++)

    {

        const uint32_t idx = scanTbl[n];

        const uint32_t idxY = idx / MLS_CG_SIZE;

        const uint32_t idxX = idx % MLS_CG_SIZE;

        absSumSign += dstCoeff[idxY * trSize + idxX];

    }

    // NOTE: when coeff block all ZERO, the lastNZPosInCG is undefined and firstNZPosInCG is 16

    return ((absSumSign << 31) | (lastNZPosInCG << 8) | firstNZPosInCG);

}

static uint32_t costCoeffNxN_c(const uint16_t *scan, const coeff_t *coeff, intptr_t trSize, uint16_t *absCoeff, const uint8_t *tabSigCtx, uint32_t scanFlagMask, uint8_t *baseCtx, int offset, int scanPosSigOff, int subPosBase)

{

    ALIGN_VAR_32(uint16_t, tmpCoeff[SCAN_SET_SIZE]);

    uint32_t numNonZero = (scanPosSigOff < (SCAN_SET_SIZE - 1) ? 1 : 0);

    uint32_t sum = 0;

    // correct offset to match assembly

    absCoeff -= numNonZero;

    for (int i = 0; i < MLS_CG_SIZE; i++)

    {

        tmpCoeff[i * MLS_CG_SIZE + 0] = (uint16_t)abs(coeff[i * trSize + 0]);

        tmpCoeff[i * MLS_CG_SIZE + 1] = (uint16_t)abs(coeff[i * trSize + 1]);

        tmpCoeff[i * MLS_CG_SIZE + 2] = (uint16_t)abs(coeff[i * trSize + 2]);

        tmpCoeff[i * MLS_CG_SIZE + 3] = (uint16_t)abs(coeff[i * trSize + 3]);

    }

    do

    {

        uint32_t blkPos, sig, ctxSig;

        blkPos = scan[scanPosSigOff];

        const uint32_t posZeroMask = (subPosBase + scanPosSigOff) ? ~0 : 0;

        sig     = scanFlagMask & 1;

        scanFlagMask >>= 1;

        X265_CHECK((uint32_t)(tmpCoeff[blkPos] != 0) == sig, "sign bit mistake\n");

        if ((scanPosSigOff != 0) || (subPosBase == 0) || numNonZero)

        {

            const uint32_t cnt = tabSigCtx[blkPos] + offset;

            ctxSig = cnt & posZeroMask;

            //X265_CHECK(ctxSig == Quant::getSigCtxInc(patternSigCtx, log2TrSize, trSize, codingParameters.scan[subPosBase + scanPosSigOff], bIsLuma, codingParameters.firstSignificanceMapContext), "sigCtx mistake!\n");;

            //encodeBin(sig, baseCtx[ctxSig]);

            const uint32_t mstate = baseCtx[ctxSig];

            const uint32_t mps = mstate & 1;

            const uint32_t stateBits = PFX(entropyStateBits)[mstate ^ sig];

            uint32_t nextState = (stateBits >> 24) + mps;

            if ((mstate ^ sig) == 1)

                nextState = sig;

            X265_CHECK(sbacNext(mstate, sig) == nextState, "nextState check failure\n");

            X265_CHECK(sbacGetEntropyBits(mstate, sig) == (stateBits & 0xFFFFFF), "entropyBits check failure\n");

            baseCtx[ctxSig] = (uint8_t)nextState;