/*

 * This file is part of FFmpeg.

 *

 * FFmpeg is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation; either

 * version 2.1 of the License, or (at your option) any later version.

 *

 * FFmpeg 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

 * Lesser General Public License for more details.

 *

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

 * License along with FFmpeg; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

 */

#include <assert.h>

#include <stdint.h>

#include <string.h>

#include "config.h"

#include "libavutil/avassert.h"

#include "libavutil/attributes.h"

#include "libavutil/imgutils.h"

#include "avcodec.h"

#include "mathops.h"

#include "mpegvideoencdsp.h"

static void denoise_dct_c(int16_t block[64], int dct_error_sum[64],

                          const uint16_t dct_offset[64])

{

    for (int i = 0; i < 64; ++i) {

        int level = block[i];

        if (level) {

            if (level > 0) {

                dct_error_sum[i] += level;

                level -= dct_offset[i];

                if (level < 0)

                    level = 0;

            } else {

                dct_error_sum[i] -= level;

                level += dct_offset[i];

                if (level > 0)

                    level = 0;

            }

            block[i] = level;

        }

    }

}

static int try_8x8basis_c(const int16_t rem[64], const int16_t weight[64],

                          const int16_t basis[64], int scale)

{

    int i;

    unsigned int sum = 0;

    for (i = 0; i < 8 * 8; i++) {

        int b = rem[i] + ((basis[i] * scale +

                           (1 << (BASIS_SHIFT - RECON_SHIFT - 1))) >>

                          (BASIS_SHIFT - RECON_SHIFT));

        int w = weight[i];

        b >>= RECON_SHIFT;

        av_assert2(-512 < b && b < 512);

        sum += (w * b) * (w * b) >> 4;

    }

    return sum >> 2;

}

static void add_8x8basis_c(int16_t rem[64], const int16_t basis[64], int scale)

{

    int i;

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

        rem[i] += (basis[i] * scale +

                   (1 << (BASIS_SHIFT - RECON_SHIFT - 1))) >>

                  (BASIS_SHIFT - RECON_SHIFT);

}

static int pix_sum_c(const uint8_t *pix, ptrdiff_t line_size)

{

    int s = 0, i, j;

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

        for (j = 0; j < 16; j += 8) {

            s   += pix[0];

            s   += pix[1];

            s   += pix[2];

            s   += pix[3];

            s   += pix[4];

            s   += pix[5];

            s   += pix[6];

            s   += pix[7];

            pix += 8;

        }

        pix += line_size - 16;

    }

    return s;

}

static int pix_norm1_c(const uint8_t *pix, ptrdiff_t line_size)

{

    int s = 0, i, j;

    const uint32_t *sq = ff_square_tab + 256;

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

        for (j = 0; j < 16; j += 8) {

#if HAVE_FAST_64BIT

            register uint64_t x = *(uint64_t *) pix;

            s += sq[x         & 0xff];

            s += sq[(x >>  8) & 0xff];

            s += sq[(x >> 16) & 0xff];

            s += sq[(x >> 24) & 0xff];

            s += sq[(x >> 32) & 0xff];

            s += sq[(x >> 40) & 0xff];

            s += sq[(x >> 48) & 0xff];

            s += sq[(x >> 56) & 0xff];

#else

            register uint32_t x = *(uint32_t *) pix;

            s += sq[x         & 0xff];

            s += sq[(x >>  8) & 0xff];

            s += sq[(x >> 16) & 0xff];

            s += sq[(x >> 24) & 0xff];

            x  = *(uint32_t *) (pix + 4);

            s += sq[x         & 0xff];

            s += sq[(x >>  8) & 0xff];

            s += sq[(x >> 16) & 0xff];

            s += sq[(x >> 24) & 0xff];

#endif

            pix += 8;

        }

        pix += line_size - 16;

    }

    return s;

}

static av_always_inline void draw_edges_lr(uint8_t *ptr, ptrdiff_t wrap, int width, int height, int w)

{

    for (int i = 0; i < height; i++) {

        memset(ptr - w, ptr[0], w);

        memset(ptr + width, ptr[width - 1], w);

        ptr += wrap;

    }

}

/* draw the edges of width 'w' of an image of size width, height */

// FIXME: Check that this is OK for MPEG-4 interlaced.

static void draw_edges_8_c(uint8_t *buf, ptrdiff_t wrap, int width, int height,

                           int w, int h, int sides)

{

    uint8_t *last_line;

    int i;

    /* left and right */

    if (w == 16) {

        draw_edges_lr(buf, wrap, width, height, 16);

    } else if (w == 8) {

        draw_edges_lr(buf, wrap, width, height, 8);

    } else {

        av_assert1(w == 4);

        draw_edges_lr(buf, wrap, width, height, 4);

    }

    /* top and bottom + corners */

    buf -= w;

    last_line = buf + (height - 1) * wrap;

    if (sides & EDGE_TOP)

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

            // top

            memcpy(buf - (i + 1) * wrap, buf, width + w + w);

    if (sides & EDGE_BOTTOM)

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

            // bottom

            memcpy(last_line + (i + 1) * wrap, last_line, width + w + w);

}

/* This wrapper function only serves to convert the stride parameters

 * from ptrdiff_t to int for av_image_copy_plane(). */

static void copy_plane_wrapper(uint8_t *dst, ptrdiff_t dst_wrap,

                               const uint8_t *src, ptrdiff_t src_wrap,

                               int width, int height)

{

    av_image_copy_plane(dst, dst_wrap, src, src_wrap, width, height);

}

/* 2x2 -> 1x1 */

static void shrink22(uint8_t *dst, ptrdiff_t dst_wrap,

                     const uint8_t *src, ptrdiff_t src_wrap,

                     int width, int height)

{

    int w;

    const uint8_t *s1, *s2;

    uint8_t *d;

    for (; height > 0; height--) {

        s1 = src;

        s2 = s1 + src_wrap;

        d = dst;

        for (w = width; w >= 4; w -= 4) {

            d[0] = (s1[0] + s1[1] + s2[0] + s2[1] + 2) >> 2;

            d[1] = (s1[2] + s1[3] + s2[2] + s2[3] + 2) >> 2;

            d[2] = (s1[4] + s1[5] + s2[4] + s2[5] + 2) >> 2;

            d[3] = (s1[6] + s1[7] + s2[6] + s2[7] + 2) >> 2;

            s1 += 8;

            s2 += 8;

            d += 4;

        }

        for (; w > 0; w--) {

            d[0] = (s1[0] + s1[1] + s2[0] + s2[1] + 2) >> 2;

            s1 += 2;

            s2 += 2;

            d++;

        }

        src += 2 * src_wrap;

        dst += dst_wrap;

    }

}

/* 4x4 -> 1x1 */

static void shrink44(uint8_t *dst, ptrdiff_t dst_wrap,

                     const uint8_t *src, ptrdiff_t src_wrap,

                     int width, int height)

{

    int w;

    const uint8_t *s1, *s2, *s3, *s4;

    uint8_t *d;

    for (; height > 0; height--) {

        s1 = src;

        s2 = s1 + src_wrap;

        s3 = s2 + src_wrap;

        s4 = s3 + src_wrap;

        d = dst;

        for (w = width; w > 0; w--) {

            d[0] = (s1[0] + s1[1] + s1[2] + s1[3] +

                    s2[0] + s2[1] + s2[2] + s2[3] +

                    s3[0] + s3[1] + s3[2] + s3[3] +

                    s4[0] + s4[1] + s4[2] + s4[3] + 8) >> 4;

            s1 += 4;

            s2 += 4;

            s3 += 4;

            s4 += 4;

            d++;

        }

        src += 4 * src_wrap;

        dst += dst_wrap;

    }

}

/* 8x8 -> 1x1 */

static void shrink88(uint8_t *dst, ptrdiff_t dst_wrap,

                     const uint8_t *src, ptrdiff_t src_wrap,

                     int width, int height)

{

    int w, i;

    for (; height > 0; height--) {

        for(w = width;w > 0; w--) {

            int tmp = 0;

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

                tmp += src[0] + src[1] + src[2] + src[3] +

                       src[4] + src[5] + src[6] + src[7];

                src += src_wrap;

            }

            *(dst++) = (tmp + 32) >> 6;

            src += 8 - 8 * src_wrap;

        }

        src += 8 * src_wrap - 8 * width;

        dst += dst_wrap - width;

    }

}

av_cold void ff_mpegvideoencdsp_init(MpegvideoEncDSPContext *c,

                                     AVCodecContext *avctx)

{

    c->denoise_dct  = denoise_dct_c;

    c->try_8x8basis = try_8x8basis_c;

    c->add_8x8basis = add_8x8basis_c;

    c->shrink[0] = copy_plane_wrapper;

    c->shrink[1] = shrink22;

    c->shrink[2] = shrink44;

    c->shrink[3] = shrink88;

    c->pix_sum   = pix_sum_c;

    c->pix_norm1 = pix_norm1_c;

    c->draw_edges = draw_edges_8_c;

#if ARCH_AARCH64

    ff_mpegvideoencdsp_init_aarch64(c, avctx);

#elif ARCH_ARM

    ff_mpegvideoencdsp_init_arm(c, avctx);

#elif ARCH_PPC

    ff_mpegvideoencdsp_init_ppc(c, avctx);

#elif ARCH_RISCV

    ff_mpegvideoencdsp_init_riscv(c, avctx);

#elif ARCH_X86

    ff_mpegvideoencdsp_init_x86(c, avctx);

#elif ARCH_MIPS

    ff_mpegvideoencdsp_init_mips(c, avctx);

#endif

}