50 lines
1.1 KiB
C
50 lines
1.1 KiB
C
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// BitmEncoder.h -- the Most Significant Bit of byte is First
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#ifndef __BITM_ENCODER_H
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#define __BITM_ENCODER_H
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#include "../IStream.h"
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template<class TOutByte>
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class CBitmEncoder
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{
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unsigned _bitPos;
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Byte _curByte;
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TOutByte _stream;
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public:
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bool Create(UInt32 bufferSize) { return _stream.Create(bufferSize); }
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void SetStream(ISequentialOutStream *outStream) { _stream.SetStream(outStream);}
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UInt64 GetProcessedSize() const { return _stream.GetProcessedSize() + ((8 - _bitPos + 7) >> 3); }
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void Init()
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{
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_stream.Init();
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_bitPos = 8;
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_curByte = 0;
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}
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HRESULT Flush()
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{
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if (_bitPos < 8)
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WriteBits(0, _bitPos);
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return _stream.Flush();
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}
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void WriteBits(UInt32 value, unsigned numBits)
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{
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while (numBits > 0)
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{
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if (numBits < _bitPos)
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{
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_curByte |= ((Byte)value << (_bitPos -= numBits));
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return;
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}
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numBits -= _bitPos;
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UInt32 newBits = (value >> numBits);
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value -= (newBits << numBits);
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_stream.WriteByte((Byte)(_curByte | newBits));
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_bitPos = 8;
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_curByte = 0;
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}
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}
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};
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#endif
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