vp8/decoder/treereader.h

/*
 *  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.
 */


#ifndef tree_reader_h
#define tree_reader_h 1

#include "vp8/common/treecoder.h"

#include "dboolhuff.h"

typedef BOOL_DECODER vp9_reader;

#define vp9_read decode_bool
#define vp9_read_literal decode_value
#define vp9_read_bit(R) vp9_read(R, vp9_prob_half)

/* Intent of tree data structure is to make decoding trivial. */

static int treed_read(vp9_reader *const r, /* !!! must return a 0 or 1 !!! */
                      vp9_tree t,
                      const vp9_prob *const p) {
  register vp9_tree_index i = 0;

  while ((i = t[ i + vp9_read(r, p[i >> 1])]) > 0);

  return -i;
}

#endif /* tree_reader_h */