/*
 * HEVC video decoder
 *
 * Copyright (C) 2012 - 2013 Guillaume Martres
 *
 * 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 "libavutil/pixdesc.h"

#include "bit_depth_template.c"
#include "hevcpred.h"

#define POS(x, y) src[(x) + stride * (y)]

static av_always_inline void FUNC(intra_pred)(HEVCContext *s, int x0, int y0,
                                              int log2_size, int c_idx)
{
#define PU(x) \
    ((x) >> s->ps.sps->log2_min_pu_size)
#define MVF(x, y) \
    (s->ref->tab_mvf[(x) + (y) * min_pu_width])
#define MVF_PU(x, y) \
    MVF(PU(x0 + ((x) << hshift)), PU(y0 + ((y) << vshift)))
#define IS_INTRA(x, y) \
    (MVF_PU(x, y).pred_flag == PF_INTRA)
#define MIN_TB_ADDR_ZS(x, y) \
    s->ps.pps->min_tb_addr_zs[(y) * (s->ps.sps->tb_mask+2) + (x)]
#define EXTEND(ptr, val, len)         \
do {                                  \
    pixel4 pix = PIXEL_SPLAT_X4(val); \
    for (i = 0; i < (len); i += 4)    \
        AV_WN4P(ptr + i, pix);        \
} while (0)

#define EXTEND_RIGHT_CIP(ptr, start, length)                                   \
        for (i = start; i < (start) + (length); i += 4)                        \
            if (!IS_INTRA(i, -1))                                              \
                AV_WN4P(&ptr[i], a);                                           \
            else                                                               \
                a = PIXEL_SPLAT_X4(ptr[i+3])
#define EXTEND_LEFT_CIP(ptr, start, length) \
        for (i = start; i > (start) - (length); i--) \
            if (!IS_INTRA(i - 1, -1)) \
                ptr[i - 1] = ptr[i]
#define EXTEND_UP_CIP(ptr, start, length)                                      \
        for (i = (start); i > (start) - (length); i -= 4)                      \
            if (!IS_INTRA(-1, i - 3))                                          \
                AV_WN4P(&ptr[i - 3], a);                                       \
            else                                                               \
                a = PIXEL_SPLAT_X4(ptr[i - 3])
#define EXTEND_DOWN_CIP(ptr, start, length)                                    \
        for (i = start; i < (start) + (length); i += 4)                        \
            if (!IS_INTRA(-1, i))                                              \
                AV_WN4P(&ptr[i], a);                                           \
            else                                                               \
                a = PIXEL_SPLAT_X4(ptr[i + 3])

    HEVCLocalContext *lc = s->HEVClc;
    int i;
    int hshift = s->ps.sps->hshift[c_idx];
    int vshift = s->ps.sps->vshift[c_idx];
    int size = (1 << log2_size);
    int size_in_luma_h = size << hshift;
    int size_in_tbs_h  = size_in_luma_h >> s->ps.sps->log2_min_tb_size;
    int size_in_luma_v = size << vshift;
    int size_in_tbs_v  = size_in_luma_v >> s->ps.sps->log2_min_tb_size;
    int x = x0 >> hshift;
    int y = y0 >> vshift;
    int x_tb = (x0 >> s->ps.sps->log2_min_tb_size) & s->ps.sps->tb_mask;
    int y_tb = (y0 >> s->ps.sps->log2_min_tb_size) & s->ps.sps->tb_mask;

    int cur_tb_addr = MIN_TB_ADDR_ZS(x_tb, y_tb);

    ptrdiff_t stride = s->frame->linesize[c_idx] / sizeof(pixel);
    pixel *src = (pixel*)s->frame->data[c_idx] + x + y * stride;

    int min_pu_width = s->ps.sps->min_pu_width;

    enum IntraPredMode mode = c_idx ? lc->tu.intra_pred_mode_c :
                              lc->tu.intra_pred_mode;
    pixel4 a;
    pixel  left_array[2 * MAX_TB_SIZE + 1];
    pixel  filtered_left_array[2 * MAX_TB_SIZE + 1];
    pixel  top_array[2 * MAX_TB_SIZE + 1];
    pixel  filtered_top_array[2 * MAX_TB_SIZE + 1];

    pixel  *left          = left_array + 1;
    pixel  *top           = top_array  + 1;
    pixel  *filtered_left = filtered_left_array + 1;
    pixel  *filtered_top  = filtered_top_array  + 1;
    int cand_bottom_left = lc->na.cand_bottom_left && cur_tb_addr > MIN_TB_ADDR_ZS( x_tb - 1, (y_tb + size_in_tbs_v) & s->ps.sps->tb_mask);
    int cand_left        = lc->na.cand_left;
    int cand_up_left     = lc->na.cand_up_left;
    int cand_up          = lc->na.cand_up;
    int cand_up_right    = lc->na.cand_up_right    && cur_tb_addr > MIN_TB_ADDR_ZS((x_tb + size_in_tbs_h) & s->ps.sps->tb_mask, y_tb - 1);

    int bottom_left_size = (FFMIN(y0 + 2 * size_in_luma_v, s->ps.sps->height) -
                           (y0 + size_in_luma_v)) >> vshift;
    int top_right_size   = (FFMIN(x0 + 2 * size_in_luma_h, s->ps.sps->width) -
                           (x0 + size_in_luma_h)) >> hshift;

    if (s->ps.pps->constrained_intra_pred_flag == 1) {
        int size_in_luma_pu_v = PU(size_in_luma_v);
        int size_in_luma_pu_h = PU(size_in_luma_h);
        int on_pu_edge_x    = !av_mod_uintp2(x0, s->ps.sps->log2_min_pu_size);
        int on_pu_edge_y    = !av_mod_uintp2(y0, s->ps.sps->log2_min_pu_size);
        if (!size_in_luma_pu_h)
            size_in_luma_pu_h++;
        if (cand_bottom_left == 1 && on_pu_edge_x) {
            int x_left_pu   = PU(x0 - 1);
            int y_bottom_pu = PU(y0 + size_in_luma_v);
            int max = FFMIN(size_in_luma_pu_v, s->ps.sps->min_pu_height - y_bottom_pu);
            cand_bottom_left = 0;
            for (i = 0; i < max; i += 2)
                cand_bottom_left |= (MVF(x_left_pu, y_bottom_pu + i).pred_flag == PF_INTRA);
        }
        if (cand_left == 1 && on_pu_edge_x) {
            int x_left_pu   = PU(x0 - 1);
            int y_left_pu   = PU(y0);
            int max = FFMIN(size_in_luma_pu_v, s->ps.sps->min_pu_height - y_left_pu);
            cand_left = 0;
            for (i = 0; i < max; i += 2)
                cand_left |= (MVF(x_left_pu, y_left_pu + i).pred_flag == PF_INTRA);
        }
        if (cand_up_left == 1) {
            int x_left_pu   = PU(x0 - 1);
            int y_top_pu    = PU(y0 - 1);
            cand_up_left = MVF(x_left_pu, y_top_pu).pred_flag == PF_INTRA;
        }
        if (cand_up == 1 && on_pu_edge_y) {
            int x_top_pu    = PU(x0);
            int y_top_pu    = PU(y0 - 1);
            int max = FFMIN(size_in_luma_pu_h, s->ps.sps->min_pu_width - x_top_pu);
            cand_up = 0;
            for (i = 0; i < max; i += 2)
                cand_up |= (MVF(x_top_pu + i, y_top_pu).pred_flag == PF_INTRA);
        }
        if (cand_up_right == 1 && on_pu_edge_y) {
            int y_top_pu    = PU(y0 - 1);
            int x_right_pu  = PU(x0 + size_in_luma_h);
            int max = FFMIN(size_in_luma_pu_h, s->ps.sps->min_pu_width - x_right_pu);
            cand_up_right = 0;
            for (i = 0; i < max; i += 2)
                cand_up_right |= (MVF(x_right_pu + i, y_top_pu).pred_flag == PF_INTRA);
        }
        memset(left, 128, 2 * MAX_TB_SIZE*sizeof(pixel));
        memset(top , 128, 2 * MAX_TB_SIZE*sizeof(pixel));
        top[-1] = 128;
    }
    if (cand_up_left) {
        left[-1] = POS(-1, -1);
        top[-1]  = left[-1];
    }
    if (cand_up)
        memcpy(top, src - stride, size * sizeof(pixel));
    if (cand_up_right) {
        memcpy(top + size, src - stride + size, size * sizeof(pixel));
        EXTEND(top + size + top_right_size, POS(size + top_right_size - 1, -1),
               size - top_right_size);
    }
    if (cand_left)
        for (i = 0; i < size; i++)
            left[i] = POS(-1, i);
    if (cand_bottom_left) {
        for (i = size; i < size + bottom_left_size; i++)
            left[i] = POS(-1, i);
        EXTEND(left + size + bottom_left_size, POS(-1, size + bottom_left_size - 1),
               size - bottom_left_size);
    }

    if (s->ps.pps->constrained_intra_pred_flag == 1) {
        if (cand_bottom_left || cand_left || cand_up_left || cand_up || cand_up_right) {
            int size_max_x = x0 + ((2 * size) << hshift) < s->ps.sps->width ?
                                    2 * size : (s->ps.sps->width - x0) >> hshift;
            int size_max_y = y0 + ((2 * size) << vshift) < s->ps.sps->height ?
                                    2 * size : (s->ps.sps->height - y0) >> vshift;
            int j = size + (cand_bottom_left? bottom_left_size: 0) -1;
            if (!cand_up_right) {
                size_max_x = x0 + ((size) << hshift) < s->ps.sps->width ?
                                                    size : (s->ps.sps->width - x0) >> hshift;
            }
            if (!cand_bottom_left) {
                size_max_y = y0 + (( size) << vshift) < s->ps.sps->height ?
                                                     size : (s->ps.sps->height - y0) >> vshift;
            }
            if (cand_bottom_left || cand_left || cand_up_left) {
                while (j > -1 && !IS_INTRA(-1, j))
                    j--;
                if (!IS_INTRA(-1, j)) {
                    j = 0;
                    while (j < size_max_x && !IS_INTRA(j, -1))
                        j++;
                    EXTEND_LEFT_CIP(top, j, j + 1);
                    left[-1] = top[-1];
                }
            } else {
                j = 0;
                while (j < size_max_x && !IS_INTRA(j, -1))
                    j++;
                if (j > 0)
                    if (x0 > 0) {
                        EXTEND_LEFT_CIP(top, j, j + 1);
                    } else {
                        EXTEND_LEFT_CIP(top, j, j);
                        top[-1] = top[0];
                    }
                left[-1] = top[-1];
            }
            left[-1] = top[-1];
            if (cand_bottom_left || cand_left) {
                a = PIXEL_SPLAT_X4(left[-1]);
                EXTEND_DOWN_CIP(left, 0, size_max_y);
            }
            if (!cand_left)
                EXTEND(left, left[-1], size);
            if (!cand_bottom_left)
                EXTEND(left + size, left[size - 1], size);
            if (x0 != 0 && y0 != 0) {
                a = PIXEL_SPLAT_X4(left[size_max_y - 1]);
                EXTEND_UP_CIP(left, size_max_y - 1, size_max_y);
                if (!IS_INTRA(-1, - 1))
                    left[-1] = left[0];
            } else if (x0 == 0) {
                EXTEND(left, 0, size_max_y);
            } else {
                a = PIXEL_SPLAT_X4(left[size_max_y - 1]);
                EXTEND_UP_CIP(left, size_max_y - 1, size_max_y);
            }
            top[-1] = left[-1];
            if (y0 != 0) {
                a = PIXEL_SPLAT_X4(left[-1]);
                EXTEND_RIGHT_CIP(top, 0, size_max_x);
            }
        }
    }
    // Infer the unavailable samples
    if (!cand_bottom_left) {
        if (cand_left) {
            EXTEND(left + size, left[size - 1], size);
        } else if (cand_up_left) {
            EXTEND(left, left[-1], 2 * size);
            cand_left = 1;
        } else if (cand_up) {
            left[-1] = top[0];
            EXTEND(left, left[-1], 2 * size);
            cand_up_left = 1;
            cand_left    = 1;
        } else if (cand_up_right) {
            EXTEND(top, top[size], size);
            left[-1] = top[size];
            EXTEND(left, left[-1], 2 * size);
            cand_up      = 1;
            cand_up_left = 1;
            cand_left    = 1;
        } else { // No samples available
            left[-1] = (1 << (BIT_DEPTH - 1));
            EXTEND(top,  left[-1], 2 * size);
            EXTEND(left, left[-1], 2 * size);
        }
    }

    if (!cand_left)
        EXTEND(left, left[size], size);
    if (!cand_up_left) {
        left[-1] = left[0];
    }
    if (!cand_up)
        EXTEND(top, left[-1], size);
    if (!cand_up_right)
        EXTEND(top + size, top[size - 1], size);

    top[-1] = left[-1];

    // Filtering process
    if (!s->ps.sps->intra_smoothing_disabled_flag && (c_idx == 0  || s->ps.sps->chroma_format_idc == 3)) {
        if (mode != INTRA_DC && size != 4){
            int intra_hor_ver_dist_thresh[] = { 7, 1, 0 };
            int min_dist_vert_hor = FFMIN(FFABS((int)(mode - 26U)),
                                          FFABS((int)(mode - 10U)));
            if (min_dist_vert_hor > intra_hor_ver_dist_thresh[log2_size - 3]) {
                int threshold = 1 << (BIT_DEPTH - 5);
                if (s->ps.sps->sps_strong_intra_smoothing_enable_flag && c_idx == 0 &&
                    log2_size == 5 &&
                    FFABS(top[-1]  + top[63]  - 2 * top[31])  < threshold &&
                    FFABS(left[-1] + left[63] - 2 * left[31]) < threshold) {
                    // We can't just overwrite values in top because it could be
                    // a pointer into src
                    filtered_top[-1] = top[-1];
                    filtered_top[63] = top[63];
                    for (i = 0; i < 63; i++)
                        filtered_top[i] = ((64 - (i + 1)) * top[-1] +
                                           (i + 1)  * top[63] + 32) >> 6;
                    for (i = 0; i < 63; i++)
                        left[i] = ((64 - (i + 1)) * left[-1] +
                                   (i + 1)  * left[63] + 32) >> 6;
                    top = filtered_top;
                } else {
                    filtered_left[2 * size - 1] = left[2 * size - 1];
                    filtered_top[2 * size - 1]  = top[2 * size - 1];
                    for (i = 2 * size - 2; i >= 0; i--)
                        filtered_left[i] = (left[i + 1] + 2 * left[i] +
                                            left[i - 1] + 2) >> 2;
                    filtered_top[-1]  =
                    filtered_left[-1] = (left[0] + 2 * left[-1] + top[0] + 2) >> 2;
                    for (i = 2 * size - 2; i >= 0; i--)
                        filtered_top[i] = (top[i + 1] + 2 * top[i] +
                                           top[i - 1] + 2) >> 2;
                    left = filtered_left;
                    top  = filtered_top;
                }
            }
        }
    }

    switch (mode) {
    case INTRA_PLANAR:
        s->hpc.pred_planar[log2_size - 2]((uint8_t *)src, (uint8_t *)top,
                                          (uint8_t *)left, stride);
        break;
    case INTRA_DC:
        s->hpc.pred_dc((uint8_t *)src, (uint8_t *)top,
                       (uint8_t *)left, stride, log2_size, c_idx);
        break;
    default:
        s->hpc.pred_angular[log2_size - 2]((uint8_t *)src, (uint8_t *)top,
                                           (uint8_t *)left, stride, c_idx,
                                           mode);
        break;
    }
}

#define INTRA_PRED(size)                                                            \
static void FUNC(intra_pred_ ## size)(HEVCContext *s, int x0, int y0, int c_idx)    \
{                                                                                   \
    FUNC(intra_pred)(s, x0, y0, size, c_idx);                                       \
}

INTRA_PRED(2)
INTRA_PRED(3)
INTRA_PRED(4)
INTRA_PRED(5)

#undef INTRA_PRED

static av_always_inline void FUNC(pred_planar)(uint8_t *_src, const uint8_t *_top,
                                  const uint8_t *_left, ptrdiff_t stride,
                                  int trafo_size)
{
    int x, y;
    pixel *src        = (pixel *)_src;
    const pixel *top  = (const pixel *)_top;
    const pixel *left = (const pixel *)_left;
    int size = 1 << trafo_size;
    for (y = 0; y < size; y++)
        for (x = 0; x < size; x++)
            POS(x, y) = ((size - 1 - x) * left[y] + (x + 1) * top[size]  +
                         (size - 1 - y) * top[x]  + (y + 1) * left[size] + size) >> (trafo_size + 1);
}

#define PRED_PLANAR(size)\
static void FUNC(pred_planar_ ## size)(uint8_t *src, const uint8_t *top,        \
                                       const uint8_t *left, ptrdiff_t stride)   \
{                                                                               \
    FUNC(pred_planar)(src, top, left, stride, size + 2);                        \
}

PRED_PLANAR(0)
PRED_PLANAR(1)
PRED_PLANAR(2)
PRED_PLANAR(3)

#undef PRED_PLANAR

static void FUNC(pred_dc)(uint8_t *_src, const uint8_t *_top,
                          const uint8_t *_left,
                          ptrdiff_t stride, int log2_size, int c_idx)
{
    int i, j, x, y;
    int size          = (1 << log2_size);
    pixel *src        = (pixel *)_src;
    const pixel *top  = (const pixel *)_top;
    const pixel *left = (const pixel *)_left;
    int dc            = size;
    pixel4 a;
    for (i = 0; i < size; i++)
        dc += left[i] + top[i];

    dc >>= log2_size + 1;

    a = PIXEL_SPLAT_X4(dc);

    for (i = 0; i < size; i++)
        for (j = 0; j < size; j+=4)
            AV_WN4P(&POS(j, i), a);

    if (c_idx == 0 && size < 32) {
        POS(0, 0) = (left[0] + 2 * dc + top[0] + 2) >> 2;
        for (x = 1; x < size; x++)
            POS(x, 0) = (top[x] + 3 * dc + 2) >> 2;
        for (y = 1; y < size; y++)
            POS(0, y) = (left[y] + 3 * dc + 2) >> 2;
    }
}

static av_always_inline void FUNC(pred_angular)(uint8_t *_src,
                                                const uint8_t *_top,
                                                const uint8_t *_left,
                                                ptrdiff_t stride, int c_idx,
                                                int mode, int size)
{
    int x, y;
    pixel *src        = (pixel *)_src;
    const pixel *top  = (const pixel *)_top;
    const pixel *left = (const pixel *)_left;

    static const int intra_pred_angle[] = {
         32,  26,  21,  17, 13,  9,  5, 2, 0, -2, -5, -9, -13, -17, -21, -26, -32,
        -26, -21, -17, -13, -9, -5, -2, 0, 2,  5,  9, 13,  17,  21,  26,  32
    };
    static const int inv_angle[] = {
        -4096, -1638, -910, -630, -482, -390, -315, -256, -315, -390, -482,
        -630, -910, -1638, -4096
    };

    int angle = intra_pred_angle[mode - 2];
    pixel ref_array[3 * MAX_TB_SIZE + 4];
    pixel *ref_tmp = ref_array + size;
    const pixel *ref;
    int last = (size * angle) >> 5;

    if (mode >= 18) {
        ref = top - 1;
        if (angle < 0 && last < -1) {
            for (x = 0; x <= size; x += 4)
                AV_WN4P(&ref_tmp[x], AV_RN4P(&top[x - 1]));
            for (x = last; x <= -1; x++)
                ref_tmp[x] = left[-1 + ((x * inv_angle[mode - 11] + 128) >> 8)];
            ref = ref_tmp;
        }

        for (y = 0; y < size; y++) {
            int idx  = ((y + 1) * angle) >> 5;
            int fact = ((y + 1) * angle) & 31;
            if (fact) {
                for (x = 0; x < size; x += 4) {
                    POS(x    , y) = ((32 - fact) * ref[x + idx + 1] +
                                           fact  * ref[x + idx + 2] + 16) >> 5;
                    POS(x + 1, y) = ((32 - fact) * ref[x + 1 + idx + 1] +
                                           fact  * ref[x + 1 + idx + 2] + 16) >> 5;
                    POS(x + 2, y) = ((32 - fact) * ref[x + 2 + idx + 1] +
                                           fact  * ref[x + 2 + idx + 2] + 16) >> 5;
                    POS(x + 3, y) = ((32 - fact) * ref[x + 3 + idx + 1] +
                                           fact  * ref[x + 3 + idx + 2] + 16) >> 5;
                }
            } else {
                for (x = 0; x < size; x += 4)
                    AV_WN4P(&POS(x, y), AV_RN4P(&ref[x + idx + 1]));
            }
        }
        if (mode == 26 && c_idx == 0 && size < 32) {
            for (y = 0; y < size; y++)
                POS(0, y) = av_clip_pixel(top[0] + ((left[y] - left[-1]) >> 1));
        }
    } else {
        ref = left - 1;
        if (angle < 0 && last < -1) {
            for (x = 0; x <= size; x += 4)
                AV_WN4P(&ref_tmp[x], AV_RN4P(&left[x - 1]));
            for (x = last; x <= -1; x++)
                ref_tmp[x] = top[-1 + ((x * inv_angle[mode - 11] + 128) >> 8)];
            ref = ref_tmp;
        }

        for (x = 0; x < size; x++) {
            int idx  = ((x + 1) * angle) >> 5;
            int fact = ((x + 1) * angle) & 31;
            if (fact) {
                for (y = 0; y < size; y++) {
                    POS(x, y) = ((32 - fact) * ref[y + idx + 1] +
                                       fact  * ref[y + idx + 2] + 16) >> 5;
                }
            } else {
                for (y = 0; y < size; y++)
                    POS(x, y) = ref[y + idx + 1];
            }
        }
        if (mode == 10 && c_idx == 0 && size < 32) {
            for (x = 0; x < size; x += 4) {
                POS(x,     0) = av_clip_pixel(left[0] + ((top[x    ] - top[-1]) >> 1));
                POS(x + 1, 0) = av_clip_pixel(left[0] + ((top[x + 1] - top[-1]) >> 1));
                POS(x + 2, 0) = av_clip_pixel(left[0] + ((top[x + 2] - top[-1]) >> 1));
                POS(x + 3, 0) = av_clip_pixel(left[0] + ((top[x + 3] - top[-1]) >> 1));
            }
        }
    }
}

static void FUNC(pred_angular_0)(uint8_t *src, const uint8_t *top,
                                 const uint8_t *left,
                                 ptrdiff_t stride, int c_idx, int mode)
{
    FUNC(pred_angular)(src, top, left, stride, c_idx, mode, 1 << 2);
}

static void FUNC(pred_angular_1)(uint8_t *src, const uint8_t *top,
                                 const uint8_t *left,
                                 ptrdiff_t stride, int c_idx, int mode)
{
    FUNC(pred_angular)(src, top, left, stride, c_idx, mode, 1 << 3);
}

static void FUNC(pred_angular_2)(uint8_t *src, const uint8_t *top,
                                 const uint8_t *left,
                                 ptrdiff_t stride, int c_idx, int mode)
{
    FUNC(pred_angular)(src, top, left, stride, c_idx, mode, 1 << 4);
}

static void FUNC(pred_angular_3)(uint8_t *src, const uint8_t *top,
                                 const uint8_t *left,
                                 ptrdiff_t stride, int c_idx, int mode)
{
    FUNC(pred_angular)(src, top, left, stride, c_idx, mode, 1 << 5);
}

#undef EXTEND_LEFT_CIP
#undef EXTEND_RIGHT_CIP
#undef EXTEND_UP_CIP
#undef EXTEND_DOWN_CIP
#undef IS_INTRA
#undef MVF_PU
#undef MVF
#undef PU
#undef EXTEND
#undef MIN_TB_ADDR_ZS
#undef POS