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69 lines
1.4 KiB
C++
Executable File
69 lines
1.4 KiB
C++
Executable File
// Compression/HuffmanEncoder.h
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#ifndef __COMPRESSION_HUFFMANENCODER_H
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#define __COMPRESSION_HUFFMANENCODER_H
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#include "../../../Common/Types.h"
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namespace NCompression {
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namespace NHuffman {
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const int kNumBitsInLongestCode = 20;
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struct CItem
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{
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UInt32 Freq;
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UInt32 Code;
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UInt32 Dad;
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UInt32 Len;
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};
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class CEncoder
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{
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public:
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UInt32 m_NumSymbols; // number of symbols in adwSymbol
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CItem *m_Items;
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UInt32 *m_Heap;
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UInt32 m_HeapSize;
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Byte *m_Depth;
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const Byte *m_ExtraBits;
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UInt32 m_ExtraBase;
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UInt32 m_MaxLength;
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UInt32 m_HeapLength;
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UInt32 m_BitLenCounters[kNumBitsInLongestCode + 1];
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UInt32 RemoveSmallest();
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bool Smaller(int n, int m);
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void DownHeap(UInt32 k);
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void GenerateBitLen(UInt32 maxCode, UInt32 heapMax);
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void GenerateCodes(UInt32 maxCode);
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UInt32 m_BlockBitLength;
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void Free();
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public:
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CEncoder();
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~CEncoder();
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bool Create(UInt32 numSymbols, const Byte *extraBits,
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UInt32 extraBase, UInt32 maxLength);
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void StartNewBlock();
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void AddSymbol(UInt32 symbol) { m_Items[symbol].Freq++; }
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void SetFreqs(const UInt32 *freqs);
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void BuildTree(Byte *levels);
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UInt32 GetBlockBitLength() const { return m_BlockBitLength; }
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template <class TBitEncoder>
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void CodeOneValue(TBitEncoder *bitEncoder, UInt32 symbol)
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{ bitEncoder->WriteBits(m_Items[symbol].Code, m_Items[symbol].Len); }
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};
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}}
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#endif
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