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#ifndef __COMPRESSION_BITCODER_H
#define __COMPRESSION_BITCODER_H
#include "RangeCoder.h"
#define kNumBitModelTotalBits 11
#define kBitModelTotal (1 << kNumBitModelTotalBits)
#define kNumMoveReducingBits 2
typedef UINT32 CBitDecoder;
INLINE void BitDecoderInit(CBitDecoder *bitDecoder)
{
*bitDecoder = kBitModelTotal / 2;
}
#if 0
UINT32 BitDecode(ISequentialInStream *in_stream, CBitDecoder *bitDecoder, CRangeDecoder *aRangeDecoder);
#else
INLINE UINT32 BitDecode(ISequentialInStream *in_stream, CBitDecoder *bitDecoder, CRangeDecoder *aRangeDecoder)
{
UINT32 aNewBound = (aRangeDecoder->m_Range >> kNumBitModelTotalBits) * (*bitDecoder);
if (aRangeDecoder->m_Code < aNewBound)
{
aRangeDecoder->m_Range = aNewBound;
*bitDecoder += (kBitModelTotal - *bitDecoder) >> kNumMoveBits;
if (aRangeDecoder->m_Range < kTopValue)
{
aRangeDecoder->m_Code = (aRangeDecoder->m_Code << 8) | InStreamReadByte(in_stream);
aRangeDecoder->m_Range <<= 8;
}
return 0;
}
else
{
aRangeDecoder->m_Range -= aNewBound;
aRangeDecoder->m_Code -= aNewBound;
*bitDecoder -= (*bitDecoder) >> kNumMoveBits;
if (aRangeDecoder->m_Range < kTopValue)
{
aRangeDecoder->m_Code = (aRangeDecoder->m_Code << 8) | InStreamReadByte(in_stream);
aRangeDecoder->m_Range <<= 8;
}
return 1;
}
}
#endif
#endif
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