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
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
|
#ifndef __COMPRESSION_HUFFMANENCODER_H
#define __COMPRESSION_HUFFMANENCODER_H
namespace NCompression {
namespace NHuffman {
const int kNumBitsInLongestCode = 15;
struct CItem
{
UINT32 Freq;
UINT32 Code;
UINT32 Dad;
UINT32 Len;
};
class CEncoder
{
UINT32 m_NumSymbols; // number of symbols in adwSymbol
CItem *m_Items;
UINT32 *m_Heap;
UINT32 m_HeapSize;
BYTE *m_Depth;
const BYTE *m_ExtraBits;
UINT32 m_ExtraBase;
UINT32 m_MaxLength;
UINT32 m_HeapLength;
UINT32 m_BitLenCounters[kNumBitsInLongestCode + 1];
UINT32 RemoveSmallest();
bool Smaller(int n, int m);
void DownHeap(UINT32 k);
void GenerateBitLen(UINT32 aMaxCode, UINT32 aHeapMax);
void GenerateCodes(UINT32 aMaxCode);
UINT32 m_BlockBitLength;
public:
CEncoder(UINT32 aNumSymbols, const BYTE *anExtraBits,
UINT32 anExtraBase, UINT32 aMaxLength);
~CEncoder();
void StartNewBlock();
void AddSymbol(UINT32 aSymbol)
{ m_Items[aSymbol].Freq++; }
void SetFreqs(const UINT32 *aFreqs);
void BuildTree(BYTE *aLevels);
DWORD GetBlockBitLength() const { return m_BlockBitLength; }
template <class TBitEncoder>
void CodeOneValue(TBitEncoder *aStream, UINT32 aSymbol)
{ aStream->WriteBits(m_Items[aSymbol].Code, m_Items[aSymbol].Len); }
};
}}
#endif
|
