/*

 * Copyright(c) 2019 Netflix, Inc.

 * Copyright (c) 2016, Alliance for Open Media. All rights reserved

 *

 * This source code is subject to the terms of the BSD 2 Clause License and

 * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License

 * was not distributed with this source code in the LICENSE file, you can

 * obtain it at https://www.aomedia.org/license/software-license. If the Alliance for Open

 * Media Patent License 1.0 was not distributed with this source code in the

 * PATENTS file, you can obtain it at https://www.aomedia.org/license/patent-license.

 */

#include "resize.h"

#include "utility.h"

#include "super_res.h"

#include "intra_prediction.h"

#define FILTER_BITS 7

const int16_t svt_av1_resize_filter_normative[(1 << RS_SUBPEL_BITS)][UPSCALE_NORMATIVE_TAPS] = {

#if UPSCALE_NORMATIVE_TAPS == 8

    {0, 0, 0, 128, 0, 0, 0, 0},        {0, 0, -1, 128, 2, -1, 0, 0},      {0, 1, -3, 127, 4, -2, 1, 0},

    {0, 1, -4, 127, 6, -3, 1, 0},      {0, 2, -6, 126, 8, -3, 1, 0},      {0, 2, -7, 125, 11, -4, 1, 0},

    {-1, 2, -8, 125, 13, -5, 2, 0},    {-1, 3, -9, 124, 15, -6, 2, 0},    {-1, 3, -10, 123, 18, -6, 2, -1},

    {-1, 3, -11, 122, 20, -7, 3, -1},  {-1, 4, -12, 121, 22, -8, 3, -1},  {-1, 4, -13, 120, 25, -9, 3, -1},

    {-1, 4, -14, 118, 28, -9, 3, -1},  {-1, 4, -15, 117, 30, -10, 4, -1}, {-1, 5, -16, 116, 32, -11, 4, -1},

    {-1, 5, -16, 114, 35, -12, 4, -1}, {-1, 5, -17, 112, 38, -12, 4, -1}, {-1, 5, -18, 111, 40, -13, 5, -1},

    {-1, 5, -18, 109, 43, -14, 5, -1}, {-1, 6, -19, 107, 45, -14, 5, -1}, {-1, 6, -19, 105, 48, -15, 5, -1},

    {-1, 6, -19, 103, 51, -16, 5, -1}, {-1, 6, -20, 101, 53, -16, 6, -1}, {-1, 6, -20, 99, 56, -17, 6, -1},

    {-1, 6, -20, 97, 58, -17, 6, -1},  {-1, 6, -20, 95, 61, -18, 6, -1},  {-2, 7, -20, 93, 64, -18, 6, -2},

    {-2, 7, -20, 91, 66, -19, 6, -1},  {-2, 7, -20, 88, 69, -19, 6, -1},  {-2, 7, -20, 86, 71, -19, 6, -1},

    {-2, 7, -20, 84, 74, -20, 7, -2},  {-2, 7, -20, 81, 76, -20, 7, -1},  {-2, 7, -20, 79, 79, -20, 7, -2},

    {-1, 7, -20, 76, 81, -20, 7, -2},  {-2, 7, -20, 74, 84, -20, 7, -2},  {-1, 6, -19, 71, 86, -20, 7, -2},

    {-1, 6, -19, 69, 88, -20, 7, -2},  {-1, 6, -19, 66, 91, -20, 7, -2},  {-2, 6, -18, 64, 93, -20, 7, -2},

    {-1, 6, -18, 61, 95, -20, 6, -1},  {-1, 6, -17, 58, 97, -20, 6, -1},  {-1, 6, -17, 56, 99, -20, 6, -1},

    {-1, 6, -16, 53, 101, -20, 6, -1}, {-1, 5, -16, 51, 103, -19, 6, -1}, {-1, 5, -15, 48, 105, -19, 6, -1},

    {-1, 5, -14, 45, 107, -19, 6, -1}, {-1, 5, -14, 43, 109, -18, 5, -1}, {-1, 5, -13, 40, 111, -18, 5, -1},

    {-1, 4, -12, 38, 112, -17, 5, -1}, {-1, 4, -12, 35, 114, -16, 5, -1}, {-1, 4, -11, 32, 116, -16, 5, -1},

    {-1, 4, -10, 30, 117, -15, 4, -1}, {-1, 3, -9, 28, 118, -14, 4, -1},  {-1, 3, -9, 25, 120, -13, 4, -1},

    {-1, 3, -8, 22, 121, -12, 4, -1},  {-1, 3, -7, 20, 122, -11, 3, -1},  {-1, 2, -6, 18, 123, -10, 3, -1},

    {0, 2, -6, 15, 124, -9, 3, -1},    {0, 2, -5, 13, 125, -8, 2, -1},    {0, 1, -4, 11, 125, -7, 2, 0},

    {0, 1, -3, 8, 126, -6, 2, 0},      {0, 1, -3, 6, 127, -4, 1, 0},      {0, 1, -2, 4, 127, -3, 1, 0},

    {0, 0, -1, 2, 128, -1, 0, 0},

#else

#error "Invalid value of UPSCALE_NORMATIVE_TAPS"

#endif // UPSCALE_NORMATIVE_TAPS == 8

};

// Calculates the scaled dimension given the original dimension and the scale

// denominator.

void calculate_scaled_size_helper(uint16_t* dim, uint8_t denom) {

    if (denom != SCALE_NUMERATOR && denom <= SCALE_DENOMINATOR_MAX) {

        // We need to ensure the constraint in "Appendix A" of the spec:

        // * FrameWidth is greater than or equal to 16

        // * FrameHeight is greater than or equal to 16

        // For this, we clamp the downscaled dimension to at least 16. One

        // exception: if original dimension itself was < 16, then we keep the

        // downscaled dimension to be same as the original, to ensure that resizing

        // is valid.

        const int min_dim = AOMMIN(16, *dim);

        // Use this version if we need *dim to be even

        // *width = (*width * SCALE_NUMERATOR + denom) / (2 * denom);

        // *width <<= 1;

        *dim = (uint16_t)((*dim * SCALE_NUMERATOR + denom / 2) / (denom));

        *dim = (uint16_t)AOMMAX(*dim, min_dim);

    } else if (denom == SCALE_THREE_QUATER) {

        // reference scaling resize defines denom 17 as 3/4

        *dim = (uint16_t)((3 + (*dim * 3)) >> 2);

    }

}

static int32_t av1_get_upscale_convolve_step(int in_length, int out_length) {

    return ((in_length << RS_SCALE_SUBPEL_BITS) + out_length / 2) / out_length;

}

static int32_t get_upscale_convolve_x0(int in_length, int out_length, int32_t x_step_qn) {

    const int     err = out_length * x_step_qn - (in_length << RS_SCALE_SUBPEL_BITS);

    const int32_t x0  = (-((out_length - in_length) << (RS_SCALE_SUBPEL_BITS - 1)) + out_length / 2) / out_length +

        RS_SCALE_EXTRA_OFF - err / 2;

    return (int32_t)((uint32_t)x0 & RS_SCALE_SUBPEL_MASK);

}

static void av1_convolve_horiz_rs_c(const uint8_t* src, int src_stride, uint8_t* dst, int dst_stride, int w, int h,

                                    const int16_t* x_filters, int x0_qn, int x_step_qn) {

    src -= UPSCALE_NORMATIVE_TAPS / 2 - 1;

    for (int y = 0; y < h; ++y) {

        int x_qn = x0_qn;

        for (int x = 0; x < w; ++x) {

            const uint8_t* const src_x        = &src[x_qn >> RS_SCALE_SUBPEL_BITS];

            const int            x_filter_idx = (x_qn & RS_SCALE_SUBPEL_MASK) >> RS_SCALE_EXTRA_BITS;

            assert(x_filter_idx <= RS_SUBPEL_MASK);

            const int16_t* const x_filter = &x_filters[x_filter_idx * UPSCALE_NORMATIVE_TAPS];

            int                  sum      = 0;

            for (int k = 0; k < UPSCALE_NORMATIVE_TAPS; ++k) {

                sum += src_x[k] * x_filter[k];

            }

            dst[x] = clip_pixel(ROUND_POWER_OF_TWO(sum, FILTER_BITS));

            x_qn += x_step_qn;

        }

        src += src_stride;

        dst += dst_stride;

    }

}

static void av1_highbd_convolve_horiz_rs_c(const uint16_t* src, int src_stride, uint16_t* dst, int dst_stride, int w,

                                           int h, const int16_t* x_filters, int x0_qn, int x_step_qn, int bd) {

    src -= UPSCALE_NORMATIVE_TAPS / 2 - 1;

    for (int y = 0; y < h; ++y) {

        int x_qn = x0_qn;

        for (int x = 0; x < w; ++x) {

            const uint16_t* const src_x        = &src[x_qn >> RS_SCALE_SUBPEL_BITS];

            const int             x_filter_idx = (x_qn & RS_SCALE_SUBPEL_MASK) >> RS_SCALE_EXTRA_BITS;

            assert(x_filter_idx <= RS_SUBPEL_MASK);

            const int16_t* const x_filter = &x_filters[x_filter_idx * UPSCALE_NORMATIVE_TAPS];

            int                  sum      = 0;

            for (int k = 0; k < UPSCALE_NORMATIVE_TAPS; ++k) {

                sum += src_x[k] * x_filter[k];

            }

            dst[x] = clip_pixel_highbd(ROUND_POWER_OF_TWO(sum, FILTER_BITS), bd);

            x_qn += x_step_qn;

        }

        src += src_stride;

        dst += dst_stride;

    }

}

void upscale_normative_rect(const uint8_t* const input, int height, int width, int in_stride, uint8_t* output,

                            int height2, int width2, int out_stride, int x_step_qn, int x0_qn, int pad_left,

                            int pad_right) {

    assert(width > 0);

    assert(height > 0);

    assert(width2 > 0);

    assert(height2 > 0);

    assert(height2 == height);

    /* Extend the left/right pixels of the tile column if needed

    (either because we can't sample from other tiles, or because we're at

    a frame edge).

    Save the overwritten pixels into tmp_left and tmp_right.

    Note: Because we pass input-1 to av1_convolve_horiz_rs, we need one extra

    column of border pixels compared to what we'd naively think.*/

    const int      border_cols = UPSCALE_NORMATIVE_TAPS / 2 + 1;

    uint8_t*       tmp_left    = NULL;

    uint8_t*       tmp_right   = NULL;

    uint8_t* const in_tl       = (uint8_t*)(input - border_cols);

    uint8_t* const in_tr       = (uint8_t*)(input + width);

    if (pad_left) {

        tmp_left = (uint8_t*)svt_aom_malloc(sizeof(*tmp_left) * border_cols * height);

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

            svt_memcpy(tmp_left + i * border_cols, in_tl + i * in_stride, border_cols);

            memset(in_tl + i * in_stride, input[i * in_stride], border_cols);

        }

    }

    if (pad_right) {

        tmp_right = (uint8_t*)svt_aom_malloc(sizeof(*tmp_right) * border_cols * height);

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

            svt_memcpy(tmp_right + i * border_cols, in_tr + i * in_stride, border_cols);

            memset(in_tr + i * in_stride, input[i * in_stride + width - 1], border_cols);

        }

    }

    av1_convolve_horiz_rs_c(input - 1,

                            in_stride,

                            output,

                            out_stride,

                            width2,

                            height2,

                            &svt_av1_resize_filter_normative[0][0],

                            x0_qn,

                            x_step_qn);

    /* Restore the left/right border pixels */

    if (pad_left) {

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

            svt_memcpy(in_tl + i * in_stride, tmp_left + i * border_cols, border_cols);

        }

        svt_aom_free(tmp_left);

    }

    if (pad_right) {

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

            svt_memcpy(in_tr + i * in_stride, tmp_right + i * border_cols, border_cols);

        }

        svt_aom_free(tmp_right);

    }

}

static void highbd_upscale_normative_rect(const uint8_t* const input, int height, int width, int in_stride,

                                          uint8_t* output, int height2, int width2, int out_stride, int x_step_qn,

                                          int x0_qn, int pad_left, int pad_right, int bd) {

    assert(width > 0);

    assert(height > 0);

    assert(width2 > 0);

    assert(height2 > 0);

    assert(height2 == height);

    /* Extend the left/right pixels of the tile column if needed

    (either because we can't sample from other tiles, or because we're at

    a frame edge).

    Save the overwritten pixels into tmp_left and tmp_right.

    Note: Because we pass input-1 to av1_convolve_horiz_rs, we need one extra

    column of border pixels compared to what we'd naively think.*/

    const int       border_cols = UPSCALE_NORMATIVE_TAPS / 2 + 1;

    const int       border_size = border_cols * sizeof(uint16_t);

    uint16_t*       tmp_left    = NULL;

    uint16_t*       tmp_right   = NULL;

    uint16_t* const input16     = (uint16_t*)input; //CONVERT_TO_SHORTPTR(input);

    uint16_t* const in_tl       = input16 - border_cols;

    uint16_t* const in_tr       = input16 + width;

    if (pad_left) {

        tmp_left = (uint16_t*)svt_aom_malloc(sizeof(*tmp_left) * border_cols * height);

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

            svt_memcpy(tmp_left + i * border_cols, in_tl + i * in_stride, border_size);

            svt_aom_memset16(in_tl + i * in_stride, input16[i * in_stride], border_cols);

        }

    }

    if (pad_right) {

        tmp_right = (uint16_t*)svt_aom_malloc(sizeof(*tmp_right) * border_cols * height);

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

            svt_memcpy(tmp_right + i * border_cols, in_tr + i * in_stride, border_size);

            svt_aom_memset16(in_tr + i * in_stride, input16[i * in_stride + width - 1], border_cols);

        }

    }

    av1_highbd_convolve_horiz_rs_c(((uint16_t*)(input)-1),

                                   in_stride,

                                   (uint16_t*)(output),

                                   out_stride,

                                   width2,

                                   height2,

                                   &svt_av1_resize_filter_normative[0][0],

                                   x0_qn,

                                   x_step_qn,

                                   bd);

    /*Restore the left/right border pixels*/

    if (pad_left) {

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

            svt_memcpy(in_tl + i * in_stride, tmp_left + i * border_cols, border_size);

        }

        svt_aom_free(tmp_left);

    }

    if (pad_right) {

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

            svt_memcpy(in_tr + i * in_stride, tmp_right + i * border_cols, border_size);

        }

        svt_aom_free(tmp_right);

    }

}

void svt_av1_upscale_normative_rows(const Av1Common* cm, const uint8_t* src, int src_stride, uint8_t* dst,

                                    int dst_stride, int rows, int sub_x, int bd, bool is_16bit_pipeline) {

    int       high_bd                = bd > EB_EIGHT_BIT || is_16bit_pipeline;

    const int downscaled_plane_width = ROUND_POWER_OF_TWO(cm->frm_size.frame_width, sub_x);

    const int upscaled_plane_width   = ROUND_POWER_OF_TWO(cm->frm_size.superres_upscaled_width, sub_x);

    const int superres_denom         = cm->frm_size.superres_denominator;

    TileInfo      tile_col;

    const int32_t x_step_qn = av1_get_upscale_convolve_step(downscaled_plane_width, upscaled_plane_width);

    int32_t       x0_qn     = get_upscale_convolve_x0(downscaled_plane_width, upscaled_plane_width, x_step_qn);

    for (int j = 0; j < cm->tiles_info.tile_cols; j++) {

        svt_av1_tile_set_col(&tile_col, &cm->tiles_info, cm->mi_cols, j);

        /*Determine the limits of this tile column in both the source

        and destination images.

        Note: The actual location which we start sampling from is

        (downscaled_x0 - 1 + (x0_qn/2^14)), and this quantity increases

        by exactly dst_width * (x_step_qn/2^14) pixels each iteration.*/

        const int downscaled_x0 = tile_col.mi_col_start << (MI_SIZE_LOG2 - sub_x);

        const int downscaled_x1 = tile_col.mi_col_end << (MI_SIZE_LOG2 - sub_x);

        const int src_width     = downscaled_x1 - downscaled_x0;

        const int upscaled_x0 = (downscaled_x0 * superres_denom) / SCALE_NUMERATOR;

        int       upscaled_x1;

        if (j == cm->tiles_info.tile_cols - 1) {

            /*Note that we can't just use AOMMIN here - due to rounding,

            (downscaled_x1 * superres_denom) / SCALE_NUMERATOR may be less than

            upscaled_plane_width.*/

            upscaled_x1 = upscaled_plane_width;

        } else {

            upscaled_x1 = (downscaled_x1 * superres_denom) / SCALE_NUMERATOR;

        }

        const uint8_t* const src_ptr   = src + (downscaled_x0 << high_bd);

        uint8_t* const       dst_ptr   = dst + (upscaled_x0 << high_bd);

        const int            dst_width = upscaled_x1 - upscaled_x0;

        const int pad_left  = (j == 0);

        const int pad_right = (j == cm->tiles_info.tile_cols - 1);

        if (high_bd) {

            highbd_upscale_normative_rect(src_ptr,

                                          rows,

                                          src_width,

                                          src_stride,

                                          dst_ptr,

                                          rows,

                                          dst_width,

                                          dst_stride,

                                          x_step_qn,

                                          x0_qn,

                                          pad_left,

                                          pad_right,

                                          bd);

        } else {

            upscale_normative_rect(src_ptr,

                                   rows,

                                   src_width,

                                   src_stride,

                                   dst_ptr,

                                   rows,

                                   dst_width,

                                   dst_stride,

                                   x_step_qn,

                                   x0_qn,

                                   pad_left,

                                   pad_right);

        }

        /*Update the fractional pixel offset to prepare for the next tile col*/

        x0_qn += (dst_width * x_step_qn) - (src_width << RS_SCALE_SUBPEL_BITS);

    }

}