/*

 *  Copyright (c) 2010 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_treewriter.h"

static void tree2tok(struct vp9_token *tokens, const vpx_tree_index *tree,

                     int i, int v, int l) {

  v += v;

  ++l;

  do {

    const vpx_tree_index j = tree[i++];

    if (j <= 0) {

      tokens[-j].value = v;

      tokens[-j].len = l;

    } else {

      tree2tok(tokens, tree, j, v, l);

    }

  } while (++v & 1);

}

void vp9_tokens_from_tree(struct vp9_token *tokens,

                          const vpx_tree_index *tree) {

  tree2tok(tokens, tree, 0, 0, 0);

}

static unsigned int convert_distribution(unsigned int i, vpx_tree tree,

                                         unsigned int branch_ct[][2],

                                         const unsigned int num_events[]) {

  unsigned int left, right;

  if (tree[i] <= 0)

    left = num_events[-tree[i]];

  else

    left = convert_distribution(tree[i], tree, branch_ct, num_events);

  if (tree[i + 1] <= 0)

    right = num_events[-tree[i + 1]];

  else

    right = convert_distribution(tree[i + 1], tree, branch_ct, num_events);

  branch_ct[i >> 1][0] = left;

  branch_ct[i >> 1][1] = right;

  return left + right;

}

void vp9_tree_probs_from_distribution(vpx_tree tree,

                                      unsigned int branch_ct[/* n-1 */][2],

                                      const unsigned int num_events[/* n */]) {

  convert_distribution(0, tree, branch_ct, num_events);

}