1 : /*
2 : * Copyright (c) 2010 The WebM project authors. All Rights Reserved.
3 : *
4 : * Use of this source code is governed by a BSD-style license
5 : * that can be found in the LICENSE file in the root of the source
6 : * tree. An additional intellectual property rights grant can be found
7 : * in the file PATENTS. All contributing project authors may
8 : * be found in the AUTHORS file in the root of the source tree.
9 : */
10 :
11 :
12 : #ifndef tree_reader_h
13 : #define tree_reader_h 1
14 :
15 : #include "vp8/common/treecoder.h"
16 :
17 : #include "dboolhuff.h"
18 :
19 : typedef BOOL_DECODER vp8_reader;
20 :
21 : #define vp8_read vp8dx_decode_bool
22 : #define vp8_read_literal vp8_decode_value
23 : #define vp8_read_bit( R) vp8_read( R, vp8_prob_half)
24 :
25 :
26 : /* Intent of tree data structure is to make decoding trivial. */
27 :
28 0 : static int vp8_treed_read(
29 : vp8_reader *const r, /* !!! must return a 0 or 1 !!! */
30 : vp8_tree t,
31 : const vp8_prob *const p
32 : )
33 : {
34 0 : register vp8_tree_index i = 0;
35 :
36 0 : while ((i = t[ i + vp8_read(r, p[i>>1])]) > 0) ;
37 :
38 0 : return -i;
39 : }
40 :
41 : #endif /* tree_reader_h */
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