1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
|
/* Copyright (C) Teemu Suutari */
#include "LZWDecoder.hpp"
#include "common/Common.hpp"
namespace ancient::internal
{
LZWDecoder::LZWDecoder(uint32_t maxCode,uint32_t literalCodes,uint32_t stackLength,uint32_t firstCode) :
_maxCode{maxCode},
_literalCodes{literalCodes},
_stackLength{stackLength},
_freeIndex{literalCodes},
_prevCode{firstCode},
_prefix{std::make_unique<uint32_t[]>(maxCode-literalCodes)},
_suffix{std::make_unique<uint8_t[]>(maxCode-literalCodes)},
_stack{std::make_unique<uint8_t[]>(stackLength)}
{
// nothing needed
}
void LZWDecoder::reset(uint32_t firstCode)
{
_freeIndex=_literalCodes;
_prevCode=firstCode;
}
void LZWDecoder::add(uint32_t code)
{
if (_freeIndex<_maxCode)
{
_suffix[_freeIndex-_literalCodes]=_newCode;
_prefix[_freeIndex-_literalCodes]=_prevCode;
_freeIndex++;
}
_prevCode=code;
}
}
|