p7zip/CPP/7zip/Compress/BitlEncoder.h
2017-10-11 12:35:36 +02:00

57 lines
1.3 KiB
C++

// BitlEncoder.h -- the Least Significant Bit of byte is First
#ifndef __BITL_ENCODER_H
#define __BITL_ENCODER_H
#include "../Common/OutBuffer.h"
class CBitlEncoder
{
COutBuffer _stream;
unsigned _bitPos;
Byte _curByte;
public:
bool Create(UInt32 bufSize) { return _stream.Create(bufSize); }
void SetStream(ISequentialOutStream *outStream) { _stream.SetStream(outStream); }
// unsigned GetBitPosition() const { return (8 - _bitPos); }
UInt64 GetProcessedSize() const { return _stream.GetProcessedSize() + ((8 - _bitPos + 7) >> 3); }
void Init()
{
_stream.Init();
_bitPos = 8;
_curByte = 0;
}
HRESULT Flush()
{
FlushByte();
return _stream.Flush();
}
void FlushByte()
{
if (_bitPos < 8)
_stream.WriteByte(_curByte);
_bitPos = 8;
_curByte = 0;
}
void WriteBits(UInt32 value, unsigned numBits)
{
while (numBits > 0)
{
if (numBits < _bitPos)
{
_curByte |= (value & ((1 << numBits) - 1)) << (8 - _bitPos);
_bitPos -= numBits;
return;
}
numBits -= _bitPos;
_stream.WriteByte((Byte)(_curByte | (value << (8 - _bitPos))));
value >>= _bitPos;
_bitPos = 8;
_curByte = 0;
}
}
void WriteByte(Byte b) { _stream.WriteByte(b);}
};
#endif