/*

 * 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 www.aomedia.org/license/software. 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 www.aomedia.org/license/patent.

 */

#include <limits.h>

#include "aom_mem/aom_mem.h"

#include "av1/common/pred_common.h"

#include "av1/common/tile_common.h"

#include "av1/encoder/cost.h"

#include "av1/encoder/segmentation.h"

void av1_enable_segmentation(struct segmentation *seg) {

  seg->enabled = 1;

  seg->update_map = 1;

  seg->update_data = 1;

  seg->temporal_update = 0;

}

void av1_disable_segmentation(struct segmentation *seg) {

  seg->enabled = 0;

  seg->update_map = 0;

  seg->update_data = 0;

  seg->temporal_update = 0;

}

void av1_disable_segfeature(struct segmentation *seg, int segment_id,

                            SEG_LVL_FEATURES feature_id) {

  seg->feature_mask[segment_id] &= ~(1 << feature_id);

}

void av1_clear_segdata(struct segmentation *seg, int segment_id,

                       SEG_LVL_FEATURES feature_id) {

  seg->feature_data[segment_id][feature_id] = 0;

}

static void count_segs(const AV1_COMMON *cm, MACROBLOCKD *xd,

                       const TileInfo *tile, MB_MODE_INFO **mi,

                       unsigned *no_pred_segcounts,

                       unsigned (*temporal_predictor_count)[2],

                       unsigned *t_unpred_seg_counts, int bw, int bh,

                       int mi_row, int mi_col) {

  const CommonModeInfoParams *const mi_params = &cm->mi_params;

  if (mi_row >= mi_params->mi_rows || mi_col >= mi_params->mi_cols) return;

  xd->mi = mi;

  set_mi_row_col(xd, tile, mi_row, bh, mi_col, bw, mi_params->mi_rows,

                 mi_params->mi_cols);

  // Count the number of hits on each segment with no prediction

  const int segment_id = xd->mi[0]->segment_id;

  no_pred_segcounts[segment_id]++;

  // Temporal prediction not allowed on key frames

  if (cm->current_frame.frame_type != KEY_FRAME) {

    const BLOCK_SIZE bsize = xd->mi[0]->bsize;

    // Test to see if the segment id matches the predicted value.

    const int pred_segment_id =

        cm->last_frame_seg_map

            ? get_segment_id(mi_params, cm->last_frame_seg_map, bsize, mi_row,

                             mi_col)

            : 0;

    const int pred_flag = pred_segment_id == segment_id;

    const int pred_context = av1_get_pred_context_seg_id(xd);

    // Store the prediction status for this mb and update counts

    // as appropriate

    xd->mi[0]->seg_id_predicted = pred_flag;

    temporal_predictor_count[pred_context][pred_flag]++;

    // Update the "unpredicted" segment count

    if (!pred_flag) t_unpred_seg_counts[segment_id]++;

  }

}

static void count_segs_sb(const AV1_COMMON *cm, MACROBLOCKD *xd,

                          const TileInfo *tile, MB_MODE_INFO **mi,

                          unsigned *no_pred_segcounts,

                          unsigned (*temporal_predictor_count)[2],

                          unsigned *t_unpred_seg_counts, int mi_row, int mi_col,

                          BLOCK_SIZE bsize) {

  const CommonModeInfoParams *const mi_params = &cm->mi_params;

  const int mis = mi_params->mi_stride;

  const int bs = mi_size_wide[bsize], hbs = bs / 2;

  PARTITION_TYPE partition;

  const int qbs = bs / 4;

  if (mi_row >= mi_params->mi_rows || mi_col >= mi_params->mi_cols) return;

#define CSEGS(cs_bw, cs_bh, cs_rowoff, cs_coloff)                              \

  count_segs(cm, xd, tile, mi + mis * (cs_rowoff) + (cs_coloff),               \

             no_pred_segcounts, temporal_predictor_count, t_unpred_seg_counts, \

             (cs_bw), (cs_bh), mi_row + (cs_rowoff), mi_col + (cs_coloff));

  if (bsize == BLOCK_8X8)

    partition = PARTITION_NONE;

  else

    partition = get_partition(cm, mi_row, mi_col, bsize);

  switch (partition) {

    case PARTITION_NONE: CSEGS(bs, bs, 0, 0); break;

    case PARTITION_HORZ:

      CSEGS(bs, hbs, 0, 0);

      CSEGS(bs, hbs, hbs, 0);

      break;

    case PARTITION_VERT:

      CSEGS(hbs, bs, 0, 0);

      CSEGS(hbs, bs, 0, hbs);

      break;

    case PARTITION_HORZ_A:

      CSEGS(hbs, hbs, 0, 0);

      CSEGS(hbs, hbs, 0, hbs);

      CSEGS(bs, hbs, hbs, 0);

      break;

    case PARTITION_HORZ_B:

      CSEGS(bs, hbs, 0, 0);

      CSEGS(hbs, hbs, hbs, 0);

      CSEGS(hbs, hbs, hbs, hbs);

      break;

    case PARTITION_VERT_A:

      CSEGS(hbs, hbs, 0, 0);

      CSEGS(hbs, hbs, hbs, 0);

      CSEGS(hbs, bs, 0, hbs);

      break;

    case PARTITION_VERT_B:

      CSEGS(hbs, bs, 0, 0);

      CSEGS(hbs, hbs, 0, hbs);

      CSEGS(hbs, hbs, hbs, hbs);

      break;

    case PARTITION_HORZ_4:

      CSEGS(bs, qbs, 0, 0);

      CSEGS(bs, qbs, qbs, 0);

      CSEGS(bs, qbs, 2 * qbs, 0);

      if (mi_row + 3 * qbs < mi_params->mi_rows) CSEGS(bs, qbs, 3 * qbs, 0);

      break;

    case PARTITION_VERT_4:

      CSEGS(qbs, bs, 0, 0);

      CSEGS(qbs, bs, 0, qbs);

      CSEGS(qbs, bs, 0, 2 * qbs);

      if (mi_col + 3 * qbs < mi_params->mi_cols) CSEGS(qbs, bs, 0, 3 * qbs);

      break;

    case PARTITION_SPLIT: {

      const BLOCK_SIZE subsize = get_partition_subsize(bsize, PARTITION_SPLIT);

      int n;

      assert(subsize < BLOCK_SIZES_ALL);

      for (n = 0; n < 4; n++) {

        const int mi_dc = hbs * (n & 1);

        const int mi_dr = hbs * (n >> 1);

        count_segs_sb(cm, xd, tile, &mi[mi_dr * mis + mi_dc], no_pred_segcounts,

                      temporal_predictor_count, t_unpred_seg_counts,

                      mi_row + mi_dr, mi_col + mi_dc, subsize);

      }

    } break;

    default: assert(0);

  }

#undef CSEGS

}

void av1_choose_segmap_coding_method(AV1_COMMON *cm, MACROBLOCKD *xd) {

  struct segmentation *seg = &cm->seg;

  struct segmentation_probs *segp = &cm->fc->seg;

  int no_pred_cost;

  int t_pred_cost = INT_MAX;

  int tile_col, tile_row, mi_row, mi_col;

  if (!seg->update_map) return;

  if (cm->features.primary_ref_frame == PRIMARY_REF_NONE) {

    seg->temporal_update = 0;

    assert(seg->update_data == 1);

    return;

  }

  unsigned temporal_predictor_count[SEG_TEMPORAL_PRED_CTXS][2] = { { 0 } };

  unsigned no_pred_segcounts[MAX_SEGMENTS] = { 0 };

  unsigned t_unpred_seg_counts[MAX_SEGMENTS] = { 0 };

  (void)xd;

  int scale_up = cm->prev_frame && (cm->width > cm->prev_frame->width ||

                                    cm->height > cm->prev_frame->height);

  // First of all generate stats regarding how well the last segment map

  // predicts this one

  if (!scale_up) {

    for (tile_row = 0; tile_row < cm->tiles.rows; tile_row++) {

      TileInfo tile_info;

      av1_tile_set_row(&tile_info, cm, tile_row);

      for (tile_col = 0; tile_col < cm->tiles.cols; tile_col++) {

        MB_MODE_INFO **mi_ptr;

        av1_tile_set_col(&tile_info, cm, tile_col);

        mi_ptr = cm->mi_params.mi_grid_base +

                 tile_info.mi_row_start * cm->mi_params.mi_stride +

                 tile_info.mi_col_start;

        for (mi_row = tile_info.mi_row_start; mi_row < tile_info.mi_row_end;

             mi_row += cm->seq_params->mib_size,

            mi_ptr += cm->seq_params->mib_size * cm->mi_params.mi_stride) {

          MB_MODE_INFO **mi = mi_ptr;

          for (mi_col = tile_info.mi_col_start; mi_col < tile_info.mi_col_end;

               mi_col += cm->seq_params->mib_size,

              mi += cm->seq_params->mib_size) {

            count_segs_sb(cm, xd, &tile_info, mi, no_pred_segcounts,

                          temporal_predictor_count, t_unpred_seg_counts, mi_row,

                          mi_col, cm->seq_params->sb_size);

          }

        }

      }

    }

  }

  int seg_id_cost[MAX_SEGMENTS];

  av1_cost_tokens_from_cdf(seg_id_cost, segp->tree_cdf, NULL);

  no_pred_cost = 0;

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

    no_pred_cost += no_pred_segcounts[i] * seg_id_cost[i];

  // Frames without past dependency cannot use temporal prediction

  if (cm->features.primary_ref_frame != PRIMARY_REF_NONE) {

    int pred_flag_cost[SEG_TEMPORAL_PRED_CTXS][2];

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

      av1_cost_tokens_from_cdf(pred_flag_cost[i], segp->pred_cdf[i], NULL);

    t_pred_cost = 0;

    // Cost for signaling the prediction flag.

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

      for (int j = 0; j < 2; ++j)

        t_pred_cost += temporal_predictor_count[i][j] * pred_flag_cost[i][j];

    }

    // Cost for signaling the unpredicted segment id.

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

      t_pred_cost += t_unpred_seg_counts[i] * seg_id_cost[i];

  }

  // Now choose which coding method to use.

  if (t_pred_cost < no_pred_cost) {

    assert(!cm->features.error_resilient_mode);

    seg->temporal_update = 1;

  } else {

    seg->temporal_update = 0;

  }

}

void av1_reset_segment_features(AV1_COMMON *cm) {

  struct segmentation *seg = &cm->seg;

  // Set up default state for MB feature flags

  seg->enabled = 0;

  seg->update_map = 0;

  seg->update_data = 0;

  av1_clearall_segfeatures(seg);

}