/*

 *  Copyright (c) 2014 The WebM project authors. All Rights Reserved.

 *

 *  Use of this source code is governed by a BSD-style license

 *  that can be found in the LICENSE file in the root of the source

 *  tree. An additional intellectual property rights grant can be found

 *  in the file PATENTS.  All contributing project authors may

 *  be found in the AUTHORS file in the root of the source tree.

 */

#include "vp9/encoder/vp9_context_tree.h"

#include "vp9/encoder/vp9_encoder.h"

static const BLOCK_SIZE square[] = {

  BLOCK_8X8,

  BLOCK_16X16,

  BLOCK_32X32,

  BLOCK_64X64,

};

static void alloc_mode_context(VP9_COMMON *cm, int num_4x4_blk,

                               PICK_MODE_CONTEXT *ctx) {

  const int num_blk = (num_4x4_blk < 4 ? 4 : num_4x4_blk);

  const int num_pix = num_blk << 4;

  int i, k;

  ctx->num_4x4_blk = num_blk;

  CHECK_MEM_ERROR(&cm->error, ctx->zcoeff_blk,

                  vpx_calloc(num_blk, sizeof(uint8_t)));

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

    for (k = 0; k < 3; ++k) {

      CHECK_MEM_ERROR(&cm->error, ctx->coeff[i][k],

                      vpx_memalign(32, num_pix * sizeof(*ctx->coeff[i][k])));

      CHECK_MEM_ERROR(&cm->error, ctx->qcoeff[i][k],

                      vpx_memalign(32, num_pix * sizeof(*ctx->qcoeff[i][k])));

      CHECK_MEM_ERROR(&cm->error, ctx->dqcoeff[i][k],

                      vpx_memalign(32, num_pix * sizeof(*ctx->dqcoeff[i][k])));

      CHECK_MEM_ERROR(&cm->error, ctx->eobs[i][k],

                      vpx_memalign(32, num_blk * sizeof(*ctx->eobs[i][k])));

      ctx->coeff_pbuf[i][k] = ctx->coeff[i][k];

      ctx->qcoeff_pbuf[i][k] = ctx->qcoeff[i][k];

      ctx->dqcoeff_pbuf[i][k] = ctx->dqcoeff[i][k];

      ctx->eobs_pbuf[i][k] = ctx->eobs[i][k];

    }

  }

}

static void free_mode_context(PICK_MODE_CONTEXT *ctx) {

  int i, k;

  vpx_free(ctx->zcoeff_blk);

  ctx->zcoeff_blk = 0;

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

    for (k = 0; k < 3; ++k) {

      vpx_free(ctx->coeff[i][k]);

      ctx->coeff[i][k] = 0;

      vpx_free(ctx->qcoeff[i][k]);

      ctx->qcoeff[i][k] = 0;

      vpx_free(ctx->dqcoeff[i][k]);

      ctx->dqcoeff[i][k] = 0;

      vpx_free(ctx->eobs[i][k]);

      ctx->eobs[i][k] = 0;

    }

  }

}

static void alloc_tree_contexts(VP9_COMMON *cm, PC_TREE *tree,

                                int num_4x4_blk) {

  alloc_mode_context(cm, num_4x4_blk, &tree->none);

  alloc_mode_context(cm, num_4x4_blk / 2, &tree->horizontal[0]);

  alloc_mode_context(cm, num_4x4_blk / 2, &tree->vertical[0]);

  if (num_4x4_blk > 4) {

    alloc_mode_context(cm, num_4x4_blk / 2, &tree->horizontal[1]);

    alloc_mode_context(cm, num_4x4_blk / 2, &tree->vertical[1]);

  } else {

    memset(&tree->horizontal[1], 0, sizeof(tree->horizontal[1]));

    memset(&tree->vertical[1], 0, sizeof(tree->vertical[1]));

  }

}

static void free_tree_contexts(PC_TREE *tree) {

  free_mode_context(&tree->none);

  free_mode_context(&tree->horizontal[0]);

  free_mode_context(&tree->horizontal[1]);

  free_mode_context(&tree->vertical[0]);

  free_mode_context(&tree->vertical[1]);

}

// This function sets up a tree of contexts such that at each square

// partition level. There are contexts for none, horizontal, vertical, and

// split.  Along with a block_size value and a selected block_size which

// represents the state of our search.

void vp9_setup_pc_tree(VP9_COMMON *cm, ThreadData *td) {

  int i, j;

  const int leaf_nodes = 64;

  const int tree_nodes = 64 + 16 + 4 + 1;

  int pc_tree_index = 0;

  PC_TREE *this_pc;

  PICK_MODE_CONTEXT *this_leaf;

  int square_index = 1;

  int nodes;

  vpx_free(td->leaf_tree);

  CHECK_MEM_ERROR(&cm->error, td->leaf_tree,

                  vpx_calloc(leaf_nodes, sizeof(*td->leaf_tree)));

  vpx_free(td->pc_tree);

  CHECK_MEM_ERROR(&cm->error, td->pc_tree,

                  vpx_calloc(tree_nodes, sizeof(*td->pc_tree)));

  this_pc = &td->pc_tree[0];

  this_leaf = &td->leaf_tree[0];

  // 4x4 blocks smaller than 8x8 but in the same 8x8 block share the same

  // context so we only need to allocate 1 for each 8x8 block.

  for (i = 0; i < leaf_nodes; ++i) alloc_mode_context(cm, 1, &td->leaf_tree[i]);

  // Sets up all the leaf nodes in the tree.

  for (pc_tree_index = 0; pc_tree_index < leaf_nodes; ++pc_tree_index) {

    PC_TREE *const tree = &td->pc_tree[pc_tree_index];

    tree->block_size = square[0];

    alloc_tree_contexts(cm, tree, 4);

    tree->u.leaf_split[0] = this_leaf++;

    for (j = 1; j < 4; j++) tree->u.leaf_split[j] = tree->u.leaf_split[0];

  }

  // Each node has 4 leaf nodes, fill each block_size level of the tree

  // from leafs to the root.

  for (nodes = 16; nodes > 0; nodes >>= 2) {

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

      PC_TREE *const tree = &td->pc_tree[pc_tree_index];

      alloc_tree_contexts(cm, tree, 4 << (2 * square_index));

      tree->block_size = square[square_index];

      for (j = 0; j < 4; j++) tree->u.split[j] = this_pc++;

      ++pc_tree_index;

    }

    ++square_index;

  }

  td->pc_root = &td->pc_tree[tree_nodes - 1];

  td->pc_root[0].none.best_mode_index = 2;

}

void vp9_free_pc_tree(ThreadData *td) {

  int i;

  if (td == NULL) return;

  if (td->leaf_tree != NULL) {

    // Set up all 4x4 mode contexts

    for (i = 0; i < 64; ++i) free_mode_context(&td->leaf_tree[i]);

    vpx_free(td->leaf_tree);

    td->leaf_tree = NULL;

  }

  if (td->pc_tree != NULL) {

    const int tree_nodes = 64 + 16 + 4 + 1;

    // Sets up all the leaf nodes in the tree.

    for (i = 0; i < tree_nodes; ++i) free_tree_contexts(&td->pc_tree[i]);

    vpx_free(td->pc_tree);

    td->pc_tree = NULL;

  }

}