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
|
// BitmEncoder.h -- the Most Significant Bit of byte is First
#ifndef __BITM_ENCODER_H
#define __BITM_ENCODER_H
#include "../IStream.h"
template<class TOutByte>
class CBitmEncoder
{
TOutByte m_Stream;
unsigned m_BitPos;
Byte m_CurByte;
public:
bool Create(UInt32 bufferSize) { return m_Stream.Create(bufferSize); }
void SetStream(ISequentialOutStream *outStream) { m_Stream.SetStream(outStream);}
void ReleaseStream() { m_Stream.ReleaseStream(); }
UInt64 GetProcessedSize() const { return m_Stream.GetProcessedSize() + (8 - m_BitPos + 7) / 8; }
void Init()
{
m_Stream.Init();
m_BitPos = 8;
m_CurByte = 0;
}
HRESULT Flush()
{
if (m_BitPos < 8)
WriteBits(0, m_BitPos);
return m_Stream.Flush();
}
void WriteBits(UInt32 value, unsigned numBits)
{
while (numBits > 0)
{
if (numBits < m_BitPos)
{
m_CurByte |= ((Byte)value << (m_BitPos -= numBits));
return;
}
numBits -= m_BitPos;
UInt32 newBits = (value >> numBits);
value -= (newBits << numBits);
m_Stream.WriteByte((Byte)(m_CurByte | newBits));
m_BitPos = 8;
m_CurByte = 0;
}
}
};
#endif
|
