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