stream.h

source code: Covert TXT to PDF

  virtual int lookChar();
  virtual int getRawChar();
  virtual GString *getPSFilter(char *indent);
  virtual GBool isBinary(GBool last = gTrue);

private:

  StreamPredictor *pred;	// predictor
  int early;			// early parameter
  GBool eof;			// true if at eof
  int inputBuf;			// input buffer
  int inputBits;		// number of bits in input buffer
  struct {			// decoding table
    int length;
    int head;
    Guchar tail;
  } table[4097];
  int nextCode;			// next code to be used
  int nextBits;			// number of bits in next code word
  int prevCode;			// previous code used in stream
  int newChar;			// next char to be added to table
  Guchar seqBuf[4097];		// buffer for current sequence
  int seqLength;		// length of current sequence
  int seqIndex;			// index into current sequence
  GBool first;			// first code after a table clear

  GBool processNextCode();
  void clearTable();
  int getCode();
};

//------------------------------------------------------------------------
// RunLengthStream
//------------------------------------------------------------------------

class RunLengthStream: public FilterStream {
public:

  RunLengthStream(Stream *strA);
  virtual ~RunLengthStream();
  virtual StreamKind getKind() { return strRunLength; }
  virtual void reset();
  virtual int getChar()
    { return (bufPtr >= bufEnd && !fillBuf()) ? EOF : (*bufPtr++ & 0xff); }
  virtual int lookChar()
    { return (bufPtr >= bufEnd && !fillBuf()) ? EOF : (*bufPtr & 0xff); }
  virtual GString *getPSFilter(char *indent);
  virtual GBool isBinary(GBool last = gTrue);

private:

  char buf[128];		// buffer
  char *bufPtr;			// next char to read
  char *bufEnd;			// end of buffer
  GBool eof;

  GBool fillBuf();
};

//------------------------------------------------------------------------
// CCITTFaxStream
//------------------------------------------------------------------------

struct CCITTCodeTable;

class CCITTFaxStream: public FilterStream {
public:

  CCITTFaxStream(Stream *strA, int encodingA, GBool endOfLineA,
		 GBool byteAlignA, int columnsA, int rowsA,
		 GBool endOfBlockA, GBool blackA);
  virtual ~CCITTFaxStream();
  virtual StreamKind getKind() { return strCCITTFax; }
  virtual void reset();
  virtual int getChar()
    { int c = lookChar(); buf = EOF; return c; }
  virtual int lookChar();
  virtual GString *getPSFilter(char *indent);
  virtual GBool isBinary(GBool last = gTrue);

private:

  int encoding;			// 'K' parameter
  GBool endOfLine;		// 'EndOfLine' parameter
  GBool byteAlign;		// 'EncodedByteAlign' parameter
  int columns;			// 'Columns' parameter
  int rows;			// 'Rows' parameter
  GBool endOfBlock;		// 'EndOfBlock' parameter
  GBool black;			// 'BlackIs1' parameter
  GBool eof;			// true if at eof
  GBool nextLine2D;		// true if next line uses 2D encoding
  int row;			// current row
  int inputBuf;			// input buffer
  int inputBits;		// number of bits in input buffer
  short *refLine;		// reference line changing elements
  int b1;			// index into refLine
  short *codingLine;		// coding line changing elements
  int a0;			// index into codingLine
  int outputBits;		// remaining ouput bits
  int buf;			// character buffer

  short getTwoDimCode();
  short getWhiteCode();
  short getBlackCode();
  short lookBits(int n);
  void eatBits(int n) { inputBits -= n; }
};

//------------------------------------------------------------------------
// DCTStream
//------------------------------------------------------------------------

// DCT component info
struct DCTCompInfo {
  int id;			// component ID
  int hSample, vSample;		// horiz/vert sampling resolutions
  int quantTable;		// quantization table number
  int prevDC;			// DC coefficient accumulator
};

struct DCTScanInfo {
  GBool comp[4];		// comp[i] is set if component i is
				//   included in this scan
  int numComps;			// number of components in the scan
  int dcHuffTable[4];		// DC Huffman table numbers
  int acHuffTable[4];		// AC Huffman table numbers
  int firstCoeff, lastCoeff;	// first and last DCT coefficient
  int ah, al;			// successive approximation parameters
};

// DCT Huffman decoding table
struct DCTHuffTable {
  Guchar firstSym[17];		// first symbol for this bit length
  Gushort firstCode[17];	// first code for this bit length
  Gushort numCodes[17];		// number of codes of this bit length
  Guchar sym[256];		// symbols
};

class DCTStream: public FilterStream {
public:

  DCTStream(Stream *strA);
  virtual ~DCTStream();
  virtual StreamKind getKind() { return strDCT; }
  virtual void reset();
  virtual int getChar();
  virtual int lookChar();
  virtual GString *getPSFilter(char *indent);
  virtual GBool isBinary(GBool last = gTrue);
  Stream *getRawStream() { return str; }

private:

  GBool progressive;		// set if in progressive mode
  GBool interleaved;		// set if in interleaved mode
  int width, height;		// image size
  int mcuWidth, mcuHeight;	// size of min coding unit, in data units
  int bufWidth, bufHeight;	// frameBuf size
  DCTCompInfo compInfo[4];	// info for each component
  DCTScanInfo scanInfo;		// info for the current scan
  int numComps;			// number of components in image
  int colorXform;		// need YCbCr-to-RGB transform?
  GBool gotAdobeMarker;		// set if APP14 Adobe marker was present
  int restartInterval;		// restart interval, in MCUs
  Guchar quantTables[4][64];	// quantization tables
  int numQuantTables;		// number of quantization tables
  DCTHuffTable dcHuffTables[4];	// DC Huffman tables
  DCTHuffTable acHuffTables[4];	// AC Huffman tables
  int numDCHuffTables;		// number of DC Huffman tables
  int numACHuffTables;		// number of AC Huffman tables
  Guchar *rowBuf[4][32];	// buffer for one MCU (non-progressive mode)
  int *frameBuf[4];		// buffer for frame (progressive mode)
  int comp, x, y, dy;		// current position within image/MCU
  int restartCtr;		// MCUs left until restart
  int restartMarker;		// next restart marker
  int eobRun;			// number of EOBs left in the current run
  int inputBuf;			// input buffer for variable length codes
  int inputBits;		// number of valid bits in input buffer

  void restart();
  GBool readMCURow();
  void readScan();
  GBool readDataUnit(DCTHuffTable *dcHuffTable,
		     DCTHuffTable *acHuffTable,
		     int *prevDC, int data[64]);
  GBool readProgressiveDataUnit(DCTHuffTable *dcHuffTable,
				DCTHuffTable *acHuffTable,
				int *prevDC, int data[64]);
  void decodeImage();
  void transformDataUnit(Guchar *quantTable,
			 int dataIn[64], Guchar dataOut[64]);
  int readHuffSym(DCTHuffTable *table);
  int readAmp(int size);
  int readBit();
  GBool readHeader();
  GBool readBaselineSOF();
  GBool readProgressiveSOF();
  GBool readScanInfo();
  GBool readQuantTables();
  GBool readHuffmanTables();
  GBool readRestartInterval();
  GBool readAdobeMarker();
  GBool readTrailer();
  int readMarker();
  int read16();
};

//------------------------------------------------------------------------
// FlateStream
//------------------------------------------------------------------------

#define flateWindow          32768    // buffer size
#define flateMask            (flateWindow-1)
#define flateMaxHuffman         15    // max Huffman code length
#define flateMaxCodeLenCodes    19    // max # code length codes
#define flateMaxLitCodes       288    // max # literal codes
#define flateMaxDistCodes       30    // max # distance codes

// Huffman code table entry
struct FlateCode {
  Gushort len;			// code length, in bits
  Gushort val;			// value represented by this code
};

struct FlateHuffmanTab {
  FlateCode *codes;
  int maxLen;
};

// Decoding info for length and distance code words
struct FlateDecode {
  int bits;			// # extra bits
  int first;			// first length/distance
};

class FlateStream: public FilterStream {
public:

  FlateStream(Stream *strA, int predictor, int columns,
	      int colors, int bits);
  virtual ~FlateStream();
  virtual StreamKind getKind() { return strFlate; }
  virtual void reset();
  virtual int getChar();
  virtual int lookChar();
  virtual int getRawChar();
  virtual GString *getPSFilter(char *indent);
  virtual GBool isBinary(GBool last = gTrue);

private:

  StreamPredictor *pred;	// predictor
  Guchar buf[flateWindow];	// output data buffer
  int index;			// current index into output buffer
  int remain;			// number valid bytes in output buffer
  int codeBuf;			// input buffer
  int codeSize;			// number of bits in input buffer
  int				// literal and distance code lengths
    codeLengths[flateMaxLitCodes + flateMaxDistCodes];
  FlateHuffmanTab litCodeTab;	// literal code table
  FlateHuffmanTab distCodeTab;	// distance code table
  GBool compressedBlock;	// set if reading a compressed block
  int blockLen;			// remaining length of uncompressed block
  GBool endOfBlock;		// set when end of block is reached
  GBool eof;			// set when end of stream is reached

  static int			// code length code reordering
    codeLenCodeMap[flateMaxCodeLenCodes];
  static FlateDecode		// length decoding info
    lengthDecode[flateMaxLitCodes-257];
  static FlateDecode		// distance decoding info
    distDecode[flateMaxDistCodes];

  void readSome();
  GBool startBlock();
  void loadFixedCodes();
  GBool readDynamicCodes();
  void compHuffmanCodes(int *lengths, int n, FlateHuffmanTab *tab);
  int getHuffmanCodeWord(FlateHuffmanTab *tab);
  int getCodeWord(int bits);
};

//------------------------------------------------------------------------
// EOFStream
//------------------------------------------------------------------------

class EOFStream: public FilterStream {
public:

  EOFStream(Stream *strA);
  virtual ~EOFStream();
  virtual StreamKind getKind() { return strWeird; }
  virtual void reset() {}
  virtual int getChar() { return EOF; }
  virtual int lookChar() { return EOF; }
  virtual GString *getPSFilter(char *indent)  { return NULL; }
  virtual GBool isBinary(GBool last = gTrue) { return gFalse; }
};

//------------------------------------------------------------------------
// FixedLengthEncoder
//------------------------------------------------------------------------

class FixedLengthEncoder: public FilterStream {
public:

  FixedLengthEncoder(Stream *strA, int lengthA);
  ~FixedLengthEncoder();
  virtual StreamKind getKind() { return strWeird; }
  virtual void reset();
  virtual void close();
  virtual int getChar();
  virtual int lookChar();
  virtual GString *getPSFilter(char *indent) { return NULL; }
  virtual GBool isBinary(GBool last = gTrue) { return gFalse; }
  virtual GBool isEncoder() { return gTrue; }

private:

  int length;
  int count;
};

//------------------------------------------------------------------------
// ASCIIHexEncoder
//------------------------------------------------------------------------

class ASCIIHexEncoder: public FilterStream {
public:

  ASCIIHexEncoder(Stream *strA);
  virtual ~ASCIIHexEncoder();
  virtual StreamKind getKind() { return strWeird; }
  virtual void reset();
  virtual void close();
  virtual int getChar()
    { return (bufPtr >= bufEnd && !fillBuf()) ? EOF : (*bufPtr++ & 0xff); }
  virtual int lookChar()
    { return (bufPtr >= bufEnd && !fillBuf()) ? EOF : (*bufPtr & 0xff); }
  virtual GString *getPSFilter(char *indent) { return NULL; }
  virtual GBool isBinary(GBool last = gTrue) { return gFalse; }
  virtual GBool isEncoder() { return gTrue; }

private:

  char buf[4];
  char *bufPtr;
  char *bufEnd;
  int lineLen;
  GBool eof;

  GBool fillBuf();
};

//------------------------------------------------------------------------
// ASCII85Encoder
//------------------------------------------------------------------------

class ASCII85Encoder: public FilterStream {
public:

  ASCII85Encoder(Stream *strA);
  virtual ~ASCII85Encoder();
  virtual StreamKind getKind() { return strWeird; }
  virtual void reset();
  virtual void close();
  virtual int getChar()
    { return (bufPtr >= bufEnd && !fillBuf()) ? EOF : (*bufPtr++ & 0xff); }
  virtual int lookChar()
    { return (bufPtr >= bufEnd && !fillBuf()) ? EOF : (*bufPtr & 0xff); }
  virtual GString *getPSFilter(char *indent) { return NULL; }
  virtual GBool isBinary(GBool last = gTrue) { return gFalse; }
  virtual GBool isEncoder() { return gTrue; }

private:

  char buf[8];
  char *bufPtr;
  char *bufEnd;
  int lineLen;
  GBool eof;

  GBool fillBuf();
};

//------------------------------------------------------------------------
// RunLengthEncoder
//------------------------------------------------------------------------

class RunLengthEncoder: public FilterStream {
public:

  RunLengthEncoder(Stream *strA);
  virtual ~RunLengthEncoder();
  virtual StreamKind getKind() { return strWeird; }
  virtual void reset();
  virtual void close();
  virtual int getChar()
    { return (bufPtr >= bufEnd && !fillBuf()) ? EOF : (*bufPtr++ & 0xff); }
  virtual int lookChar()
    { return (bufPtr >= bufEnd && !fillBuf()) ? EOF : (*bufPtr & 0xff); }
  virtual GString *getPSFilter(char *indent) { return NULL; }
  virtual GBool isBinary(GBool last = gTrue) { return gFalse; }
  virtual GBool isEncoder() { return gTrue; }

private:

  char buf[131];
  char *bufPtr;
  char *bufEnd;
  char *nextEnd;
  GBool eof;

  GBool fillBuf();
};

#endif