mirror of https://github.com/qpdf/qpdf.git
44 lines
1023 B
C++
44 lines
1023 B
C++
#ifndef PL_LZWDECODER_HH
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#define PL_LZWDECODER_HH
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#include <qpdf/Pipeline.hh>
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#include <qpdf/Buffer.hh>
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#include <vector>
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class Pl_LZWDecoder: public Pipeline
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{
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public:
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QPDF_DLL
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Pl_LZWDecoder(char const* identifier, Pipeline* next,
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bool early_code_change);
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QPDF_DLL
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virtual ~Pl_LZWDecoder();
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QPDF_DLL
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virtual void write(unsigned char* buf, size_t len);
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QPDF_DLL
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virtual void finish();
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private:
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void sendNextCode();
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void handleCode(unsigned int code);
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unsigned char getFirstChar(unsigned int code);
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void addToTable(unsigned char next);
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// members used for converting bits to codes
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unsigned char buf[3];
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unsigned int code_size;
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unsigned int next;
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unsigned int byte_pos;
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unsigned int bit_pos; // left to right: 01234567
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unsigned int bits_available;
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// members used for handle LZW decompression
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bool code_change_delta;
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bool eod;
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std::vector<Buffer> table;
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unsigned int last_code;
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};
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#endif // PL_LZWDECODER_HH
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