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