mirror of
https://gitlab.winehq.org/wine/wine-gecko.git
synced 2024-09-13 09:24:08 -07:00
65 lines
1.5 KiB
C
65 lines
1.5 KiB
C
/*
|
|
* Copyright (c) 2010 The VP8 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 "treecoder.h"
|
|
|
|
#include "dboolhuff.h"
|
|
|
|
typedef BOOL_DECODER vp8_reader;
|
|
|
|
#define vp8_read vp8dx_decode_bool
|
|
#define vp8_read_literal vp8_decode_value
|
|
#define vp8_read_bit( R) vp8_read( R, vp8_prob_half)
|
|
|
|
|
|
/* Intent of tree data structure is to make decoding trivial. */
|
|
|
|
static int vp8_treed_read(
|
|
vp8_reader *const r, /* !!! must return a 0 or 1 !!! */
|
|
vp8_tree t,
|
|
const vp8_prob *const p
|
|
)
|
|
{
|
|
register vp8_tree_index i = 0;
|
|
|
|
while ((i = t[ i + vp8_read(r, p[i>>1])]) > 0) ;
|
|
|
|
return -i;
|
|
}
|
|
|
|
|
|
/* Variant reads a binary number given distributions on each bit.
|
|
Note that tree is arbitrary; probability of decoding a zero
|
|
may or may not depend on previously decoded bits. */
|
|
|
|
static int vp8_treed_read_num(
|
|
vp8_reader *const r, /* !!! must return a 0 or 1 !!! */
|
|
vp8_tree t,
|
|
const vp8_prob *const p
|
|
)
|
|
{
|
|
vp8_tree_index i = 0;
|
|
int v = 0, b;
|
|
|
|
do
|
|
{
|
|
b = vp8_read(r, p[i>>1]);
|
|
v = (v << 1) + b;
|
|
}
|
|
while ((i = t[i+b]) > 0);
|
|
|
|
return v;
|
|
}
|
|
#endif /* tree_reader_h */
|