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 VP8_DECODER_TREEREADER_H_
13 #define VP8_DECODER_TREEREADER_H_
14 
15 #include "./vpx_config.h"
16 #include "vp8/common/treecoder.h"
17 #include "dboolhuff.h"
18 
19 #ifdef __cplusplus
20 extern "C" {
21 #endif
22 
23 typedef BOOL_DECODER vp8_reader;
24 
25 #define vp8_read vp8dx_decode_bool
26 #define vp8_read_literal vp8_decode_value
27 #define vp8_read_bit(R) vp8_read(R, vp8_prob_half)
28 
29 
30 /* Intent of tree data structure is to make decoding trivial. */
31 
vp8_treed_read(vp8_reader * const r,vp8_tree t,const vp8_prob * const p)32 static INLINE int vp8_treed_read(
33     vp8_reader *const r,        /* !!! must return a 0 or 1 !!! */
34     vp8_tree t,
35     const vp8_prob *const p
36 )
37 {
38     register vp8_tree_index i = 0;
39 
40     while ((i = t[ i + vp8_read(r, p[i>>1])]) > 0) ;
41 
42     return -i;
43 }
44 
45 #ifdef __cplusplus
46 }  // extern "C"
47 #endif
48 
49 #endif  // VP8_DECODER_TREEREADER_H_
50