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// 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
{
unsigned _bitPos;
Byte _curByte;
TOutByte _stream;
public:
bool Create(UInt32 bufferSize) { return _stream.Create(bufferSize); }
void SetStream(ISequentialOutStream *outStream) { _stream.SetStream(outStream);}
UInt64 GetProcessedSize() const { return _stream.GetProcessedSize() + ((8 - _bitPos + 7) >> 3); }
void Init()
{
_stream.Init();
_bitPos = 8;
_curByte = 0;
}
HRESULT Flush()
{
if (_bitPos < 8)
WriteBits(0, _bitPos);
return _stream.Flush();
}
void WriteBits(UInt32 value, unsigned numBits)
{
while (numBits > 0)
{
if (numBits < _bitPos)
{
_curByte |= ((Byte)value << (_bitPos -= numBits));
return;
}
numBits -= _bitPos;
UInt32 newBits = (value >> numBits);
value -= (newBits << numBits);
_stream.WriteByte((Byte)(_curByte | newBits));
_bitPos = 8;
_curByte = 0;
}
}
};
#endif
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