//========================================================================

//

// Stream.h

//

// Copyright 1996-2003 Glyph & Cog, LLC

//

//========================================================================

#ifndef STREAM_H

#define STREAM_H

#include <aconf.h>

#include <stdio.h>

#if HAVE_JPEGLIB

#include <jpeglib.h>

#include <setjmp.h>

#endif

#include "gtypes.h"

#include "gfile.h"

#include "Object.h"

class BaseStream;

class SharedFile;

//------------------------------------------------------------------------

enum StreamKind {

  strFile,

  strASCIIHex,

  strASCII85,

  strLZW,

  strRunLength,

  strCCITTFax,

  strDCT,

  strFlate,

  strJBIG2,

  strJPX,

  strWeird      // internal-use stream types

};

enum StreamColorSpaceMode {

  streamCSNone,

  streamCSDeviceGray,

  streamCSDeviceRGB,

  streamCSDeviceCMYK

};

//------------------------------------------------------------------------

// This is in Stream.h instead of Decrypt.h to avoid really annoying

// include file dependency loops.

enum CryptAlgorithm {

  cryptRC4,

  cryptAES,

  cryptAES256

};

//------------------------------------------------------------------------

// Stream (base class)

//------------------------------------------------------------------------

class Stream {

public:

  // Constructor.

  Stream();

  // Destructor.

  virtual ~Stream();

  virtual Stream *copy() = 0;

  // Get kind of stream.

  virtual StreamKind getKind() = 0;

  virtual GBool isEmbedStream() { return gFalse; }

  // Disable checking for 'decompression bombs', i.e., cases where the

  // encryption ratio looks suspiciously high.  This should be called

  // for things like images which (a) can have very high compression

  // ratios in certain cases, and (b) have fixed data sizes controlled

  // by the reader.

  virtual void disableDecompressionBombChecking() {}

  // Reset stream to beginning.

  virtual void reset() = 0;

  // Close down the stream.

  virtual void close();

  // Get next char from stream.

  virtual int getChar() = 0;

  // Peek at next char in stream.

  virtual int lookChar() = 0;

  // Get next char from stream without using the predictor.

  // This is only used by StreamPredictor.

  virtual int getRawChar();

  // Get exactly <size> bytes from stream.  Returns the number of

  // bytes read -- the returned count will be less than <size> at EOF.

  virtual int getBlock(char *blk, int size);

  // Get next line from stream.

  virtual char *getLine(char *buf, int size);

  // Discard the next <n> bytes from stream.  Returns the number of

  // bytes discarded, which will be less than <n> only if EOF is

  // reached.

  virtual Guint discardChars(Guint n);

  // Get current position in file.

  virtual GFileOffset getPos() = 0;

  // Go to a position in the stream.  If <dir> is negative, the

  // position is from the end of the file; otherwise the position is

  // from the start of the file.

  virtual void setPos(GFileOffset pos, int dir = 0) = 0;

  // Get PostScript command for the filter(s).

  virtual GString *getPSFilter(int psLevel, const char *indent,

             GBool okToReadStream);

  // Does this stream type potentially contain non-printable chars?

  virtual GBool isBinary(GBool last = gTrue) = 0;

  // Does this stream include a "strong" compression filter (anything

  // other than RLE)?

  virtual GBool hasStrongCompression() { return gFalse; }

  // Get the BaseStream of this stream.

  virtual BaseStream *getBaseStream() = 0;

  // Get the stream after the last decoder (this may be a BaseStream

  // or a DecryptStream).

  virtual Stream *getUndecodedStream() = 0;

  // Get the dictionary associated with this stream.

  virtual Dict *getDict() = 0;

  // Is this an encoding filter?

  virtual GBool isEncoder() { return gFalse; }

  // Get image parameters which are defined by the stream contents.

  virtual void getImageParams(int *bitsPerComponent,

            StreamColorSpaceMode *csMode) {}

  // Return the next stream in the "stack".

  virtual Stream *getNextStream() { return NULL; }

  // Add filters to this stream according to the parameters in <dict>.

  // Returns the new stream.

  Stream *addFilters(Object *dict, int recursion = 0);

private:

  Stream *makeFilter(char *name, Stream *str, Object *params,

         int recursion, GBool *ok);

};

//------------------------------------------------------------------------

// BaseStream

//

// This is the base class for all streams that read directly from a file.

//------------------------------------------------------------------------

class BaseStream: public Stream {

public:

  BaseStream(Object *dictA);

  virtual ~BaseStream();

  virtual Stream *makeSubStream(GFileOffset start, GBool limited,

        GFileOffset length, Object *dict) = 0;

  virtual void setPos(GFileOffset pos, int dir = 0) = 0;

  virtual GBool isBinary(GBool last = gTrue) { return last; }

  virtual BaseStream *getBaseStream() { return this; }

  virtual Stream *getUndecodedStream() { return this; }

  virtual Dict *getDict() { return dict.getDict(); }

  virtual GString *getFileName() { return NULL; }

  // Get/set position of first byte of stream within the file.

  virtual GFileOffset getStart() = 0;

  virtual void moveStart(int delta) = 0;

protected:

  Object dict;

};

//------------------------------------------------------------------------

// FilterStream

//

// This is the base class for all streams that filter another stream.

//------------------------------------------------------------------------

class FilterStream: public Stream {

public:

  FilterStream(Stream *strA);

  virtual ~FilterStream();

  virtual void disableDecompressionBombChecking()

    { str->disableDecompressionBombChecking(); }

  virtual void close();

  virtual GFileOffset getPos() { return str->getPos(); }

  virtual void setPos(GFileOffset pos, int dir = 0);

  virtual BaseStream *getBaseStream() { return str->getBaseStream(); }

  virtual Stream *getUndecodedStream() { return str->getUndecodedStream(); }

  virtual Dict *getDict() { return str->getDict(); }

  virtual Stream *getNextStream() { return str; }

protected:

  Stream *str;

};

//------------------------------------------------------------------------

// ImageStream

//------------------------------------------------------------------------

class ImageStream {

public:

  // Create an image stream object for an image with the specified

  // parameters.  Note that these are the actual image parameters,

  // which may be different from the predictor parameters.

  ImageStream(Stream *strA, int widthA, int nCompsA, int nBitsA);

  ~ImageStream();

  // Reset the stream.

  void reset();

  // Close down the stream.

  void close();

  // Gets the next pixel from the stream.  <pix> should be able to hold

  // at least nComps elements.  Returns false at end of file.

  GBool getPixel(Guchar *pix);

  // Returns a pointer to the next line of pixels.  Returns NULL at

  // end of file.

  Guchar *getLine();

  // Skip an entire line from the image.

  void skipLine();

private:

  Stream *str;      // base stream

  int width;      // pixels per line

  int nComps;     // components per pixel

  int nBits;      // bits per component

  int nVals;      // components per line

  int inputLineSize;    // input line buffer size

  char *inputLine;    // input line buffer

  Guchar *imgLine;    // line buffer

  int imgIdx;     // current index in imgLine

};

//------------------------------------------------------------------------

// StreamPredictor

//------------------------------------------------------------------------

class StreamPredictor {

public:

  // Create a predictor object.  Note that the parameters are for the

  // predictor, and may not match the actual image parameters.

  StreamPredictor(Stream *strA, int predictorA,

      int widthA, int nCompsA, int nBitsA);

  ~StreamPredictor();

  GBool isOk() { return ok; }

  void reset();

  int lookChar();

  int getChar();

  int getBlock(char *blk, int size);

  int getPredictor() { return predictor; }

  int getWidth() { return width; }

  int getNComps() { return nComps; }

  int getNBits() { return nBits; }

private:

  GBool getNextLine();

  Stream *str;      // base stream

  int predictor;    // predictor

  int width;      // pixels per line

  int nComps;     // components per pixel

  int nBits;      // bits per component

  int nVals;      // components per line

  int pixBytes;     // bytes per pixel

  int rowBytes;     // bytes per line

  Guchar *predLine;   // line buffer

  int predIdx;      // current index in predLine

  GBool ok;

};

//------------------------------------------------------------------------

// FileStream

//------------------------------------------------------------------------

#define fileStreamBufSize 256

class FileStream: public BaseStream {

public:

  FileStream(FILE *fA, GFileOffset startA, GBool limitedA,

       GFileOffset lengthA, Object *dictA);

  virtual ~FileStream();

  virtual Stream *copy();

  virtual Stream *makeSubStream(GFileOffset startA, GBool limitedA,

        GFileOffset lengthA, Object *dictA);

  virtual StreamKind getKind() { return strFile; }

  virtual void reset();

  virtual int getChar()

    { return (bufPtr >= bufEnd && !fillBuf()) ? EOF : (*bufPtr++ & 0xff); }

  virtual int lookChar()

    { return (bufPtr >= bufEnd && !fillBuf()) ? EOF : (*bufPtr & 0xff); }

  virtual int getBlock(char *blk, int size);

  virtual GFileOffset getPos() { return bufPos + (int)(bufPtr - buf); }

  virtual void setPos(GFileOffset pos, int dir = 0);

  virtual GFileOffset getStart() { return start; }

  virtual void moveStart(int delta);

private:

  FileStream(SharedFile *fA, GFileOffset startA, GBool limitedA,

       GFileOffset lengthA, Object *dictA);

  GBool fillBuf();

  SharedFile *f;

  GFileOffset start;

  GBool limited;

  GFileOffset length;

  char buf[fileStreamBufSize];

  char *bufPtr;

  char *bufEnd;

  GFileOffset bufPos;

};

//------------------------------------------------------------------------

// MemStream

//------------------------------------------------------------------------

class MemStream: public BaseStream {

public:

  MemStream(char *bufA, Guint startA, Guint lengthA, Object *dictA);

  virtual ~MemStream();

  virtual Stream *copy();

  virtual Stream *makeSubStream(GFileOffset start, GBool limited,

        GFileOffset lengthA, Object *dictA);

  virtual StreamKind getKind() { return strWeird; }

  virtual void reset();

  virtual void close();

  virtual int getChar()

    { return (bufPtr < bufEnd) ? (*bufPtr++ & 0xff) : EOF; }

  virtual int lookChar()

    { return (bufPtr < bufEnd) ? (*bufPtr & 0xff) : EOF; }

  virtual int getBlock(char *blk, int size);

  virtual GFileOffset getPos() { return (GFileOffset)(bufPtr - buf); }

  virtual void setPos(GFileOffset pos, int dir = 0);

  virtual GFileOffset getStart() { return start; }

  virtual void moveStart(int delta);

private:

  char *buf;

  Guint start;

  Guint length;

  char *bufEnd;

  char *bufPtr;

  GBool needFree;

};

//------------------------------------------------------------------------

// EmbedStream

//

// This is a special stream type used for embedded streams (inline

// images).  It reads directly from the base stream -- after the

// EmbedStream is deleted, reads from the base stream will proceed where

// the BaseStream left off.  Note that this is very different behavior

// that creating a new FileStream (using makeSubStream).

//------------------------------------------------------------------------

class EmbedStream: public BaseStream {

public:

  EmbedStream(Stream *strA, Object *dictA, GBool limitedA, GFileOffset lengthA);

  virtual ~EmbedStream();

  virtual Stream *copy();

  virtual Stream *makeSubStream(GFileOffset start, GBool limitedA,

        GFileOffset lengthA, Object *dictA);

  virtual StreamKind getKind() { return str->getKind(); }

  virtual GBool isEmbedStream() { return gTrue; }

  virtual void reset() {}

  virtual int getChar();

  virtual int lookChar();

  virtual int getBlock(char *blk, int size);

  virtual GFileOffset getPos() { return str->getPos(); }

  virtual void setPos(GFileOffset pos, int dir = 0);

  virtual GFileOffset getStart();

  virtual void moveStart(int delta);

private:

  Stream *str;

  GBool limited;

  GFileOffset length;

};

//------------------------------------------------------------------------

// ASCIIHexStream

//------------------------------------------------------------------------

class ASCIIHexStream: public FilterStream {

public:

  ASCIIHexStream(Stream *strA);

  virtual ~ASCIIHexStream();

  virtual Stream *copy();

  virtual StreamKind getKind() { return strASCIIHex; }

  virtual void reset();

  virtual int getChar()

    { int c = lookChar(); buf = EOF; return c; }

  virtual int lookChar();

  virtual GString *getPSFilter(int psLevel, const char *indent,

             GBool okToReadStream);

  virtual GBool isBinary(GBool last = gTrue);

private:

  int buf;

  GBool eof;

};

//------------------------------------------------------------------------

// ASCII85Stream

//------------------------------------------------------------------------

class ASCII85Stream: public FilterStream {

public:

  ASCII85Stream(Stream *strA);

  virtual ~ASCII85Stream();

  virtual Stream *copy();

  virtual StreamKind getKind() { return strASCII85; }

  virtual void reset();

  virtual int getChar()

    { int ch = lookChar(); ++index; return ch; }

  virtual int lookChar();

  virtual GString *getPSFilter(int psLevel, const char *indent,

             GBool okToReadStream);

  virtual GBool isBinary(GBool last = gTrue);

private:

  int c[5];

  int b[4];

  int index, n;

  GBool eof;

};

//------------------------------------------------------------------------

// LZWStream

//------------------------------------------------------------------------

class LZWStream: public FilterStream {

public:

  LZWStream(Stream *strA, int predictor, int columns, int colors,

      int bits, int earlyA);

  virtual ~LZWStream();

  virtual Stream *copy();

  virtual StreamKind getKind() { return strLZW; }

  virtual void disableDecompressionBombChecking();

  virtual void reset();

  virtual int getChar();

  virtual int lookChar();

  virtual int getRawChar();

  virtual int getBlock(char *blk, int size);

  virtual GString *getPSFilter(int psLevel, const char *indent,

             GBool okToReadStream);

  virtual GBool isBinary(GBool last = gTrue);

  virtual GBool hasStrongCompression() { return 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 checkForDecompressionBombs;

  unsigned long long totalIn; // total number of encoded bytes read so far

  unsigned long long totalOut;  // total number of bytes decoded so far

  GBool processNextCode();

  void clearTable();

  int getCode();

};

//------------------------------------------------------------------------

// RunLengthStream

//------------------------------------------------------------------------

class RunLengthStream: public FilterStream {

public:

  RunLengthStream(Stream *strA);

  virtual ~RunLengthStream();

  virtual Stream *copy();

  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 int getBlock(char *blk, int size);

  virtual GString *getPSFilter(int psLevel, const char *indent,

             GBool okToReadStream);

  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 Stream *copy();

  virtual StreamKind getKind() { return strCCITTFax; }

  virtual void reset();

  virtual int getChar();

  virtual int lookChar();

  virtual int getBlock(char *blk, int size);

  virtual GString *getPSFilter(int psLevel, const char *indent,

             GBool okToReadStream);

  virtual GBool isBinary(GBool last = gTrue);

  virtual GBool hasStrongCompression() { return 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

  int blackXOR;

  GBool eof;      // true if at eof

  GBool nextLine2D;   // true if next line uses 2D encoding

  int row;      // current row

  Guint inputBuf;   // input buffer

  int inputBits;    // number of bits in input buffer

  int *codingLine;    // coding line changing elements

  int *refLine;     // reference line changing elements

  int nextCol;      // next column to read

  int a0i;      // index into codingLine

  GBool err;      // error on current line

  int nErrors;      // number of errors so far in this stream

  void addPixels(int a1, int blackPixels);

  void addPixelsNeg(int a1, int blackPixels);

  GBool readRow();

  short getTwoDimCode();

  short getWhiteCode();

  short getBlackCode();

  short lookBits(int n);

  void eatBits(int n) { if ((inputBits -= n) < 0) inputBits = 0; }

};

//------------------------------------------------------------------------

// DCTStream

//------------------------------------------------------------------------

#if HAVE_JPEGLIB

class DCTStream;

#define dctStreamBufSize 4096

struct DCTSourceMgr {

  jpeg_source_mgr src;

  DCTStream *str;

  char buf[dctStreamBufSize];

};

struct DCTErrorMgr {

  struct jpeg_error_mgr err;

  jmp_buf setjmpBuf;

};

#else // HAVE_JPEGLIB

// 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

};

#endif // HAVE_JPEGLIB

class DCTStream: public FilterStream {

public:

  DCTStream(Stream *strA, int colorXformA);

  virtual ~DCTStream();

  virtual Stream *copy();

  virtual StreamKind getKind() { return strDCT; }

  virtual void reset();

  virtual void close();

  virtual int getChar();

  virtual int lookChar();

  virtual int getBlock(char *blk, int size);

  virtual GString *getPSFilter(int psLevel, const char *indent,

             GBool okToReadStream);

  virtual GBool isBinary(GBool last = gTrue);

  virtual GBool hasStrongCompression() { return gTrue; }

  Stream *getRawStream() { return str; }

private:

  GBool checkSequentialInterleaved();

#if HAVE_JPEGLIB

  int colorXform;   // color transform: -1 = unspecified

        //                   0 = none

        //                   1 = YUV/YUVK -> RGB/CMYK

  jpeg_decompress_struct decomp;

  DCTErrorMgr errorMgr;

  DCTSourceMgr sourceMgr;

  GBool error;

  char *lineBuf;

  int lineBufHeight;

  char *lineBufRows[4];

  char *bufPtr;

  char *bufEnd;

  GBool inlineImage;

  GBool fillBuf();

  static void errorExit(j_common_ptr d);

  static void errorMessage(j_common_ptr d);

  static void initSourceCbk(j_decompress_ptr d);

  static boolean fillInputBufferCbk(j_decompress_ptr d);

  static void skipInputDataCbk(j_decompress_ptr d, long numBytes);

  static void termSourceCbk(j_decompress_ptr d);

#else // HAVE_JPEGLIB

  GBool prepared;   // set after prepare() is called

  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;   // color transform: -1 = unspecified

        //                   0 = none

        //                   1 = YUV/YUVK -> RGB/CMYK

  GBool gotJFIFMarker;    // set if APP0 JFIF marker was present

  GBool gotAdobeMarker;   // set if APP14 Adobe marker was present

  int restartInterval;    // restart interval, in MCUs

  Gushort 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;

  Guchar *rowBufPtr;    // current position within rowBuf

  Guchar *rowBufEnd;    // end of valid data in rowBuf

  int *frameBuf[4];   // buffer for frame (progressive mode)

  int comp, x, y;   // 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 prepare();

  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(Gushort *quantTable,

       int dataIn[64], Guchar dataOut[64]);

  int readHuffSym(DCTHuffTable *table);

  int readAmp(int size);

  int readBit();

  GBool readHeader(GBool frame);

  GBool readBaselineSOF();

  GBool readProgressiveSOF();

  GBool readScanInfo();

  GBool readQuantTables();

  GBool readHuffmanTables();

  GBool readRestartInterval();

  GBool readJFIFMarker();

  GBool readAdobeMarker();

  GBool readTrailer();

  int readMarker();

  int read16();

#endif // HAVE_JPEGLIB

};

//------------------------------------------------------------------------

// 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 Stream *copy();

  virtual StreamKind getKind() { return strFlate; }

  virtual void disableDecompressionBombChecking();

  virtual void reset();

  virtual int getChar();

  virtual int lookChar();

  virtual int getRawChar();

  virtual int getBlock(char *blk, int size);

  virtual GString *getPSFilter(int psLevel, const char *indent,

             GBool okToReadStream);

  virtual GBool isBinary(GBool last = gTrue);

  virtual GBool hasStrongCompression() { return 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

  GBool checkForDecompressionBombs;

  unsigned long long totalIn; // total number of encoded bytes read so far

  unsigned long long totalOut;  // total number of bytes decoded so far

  static int      // code length code reordering

    codeLenCodeMap[flateMaxCodeLenCodes];

  static FlateDecode    // length decoding info

    lengthDecode[flateMaxLitCodes-257];

  static FlateDecode    // distance decoding info

    distDecode[flateMaxDistCodes];

  static FlateHuffmanTab  // fixed literal code table

    fixedLitCodeTab;

  static FlateHuffmanTab  // fixed distance code table

    fixedDistCodeTab;

  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 Stream *copy();

  virtual StreamKind getKind() { return strWeird; }

  virtual void reset() {}

  virtual int getChar() { return EOF; }

  virtual int lookChar() { return EOF; }

  virtual int getBlock(char *blk, int size) { return 0; }

  virtual GString *getPSFilter(int psLevel, const char *indent,

             GBool okToReadStream)

    { return NULL; }

  virtual GBool isBinary(GBool last = gTrue) { return gFalse; }

};

//------------------------------------------------------------------------

// BufStream

//------------------------------------------------------------------------

class BufStream: public FilterStream {

public:

  BufStream(Stream *strA, int bufSizeA);

  virtual ~BufStream();

  virtual Stream *copy();

  virtual StreamKind getKind() { return strWeird; }

  virtual void reset();

  virtual int getChar();

  virtual int lookChar();

  virtual GString *getPSFilter(int psLevel, const char *indent,

             GBool okToReadStream)

    { return NULL; }

  virtual GBool isBinary(GBool last = gTrue);

  int lookChar(int idx);

private:

  int *buf;

  int bufSize;

};

//------------------------------------------------------------------------

// FixedLengthEncoder

//------------------------------------------------------------------------

class FixedLengthEncoder: public FilterStream {

public:

  FixedLengthEncoder(Stream *strA, int lengthA);

  ~FixedLengthEncoder();

  virtual Stream *copy();

  virtual StreamKind getKind() { return strWeird; }

  virtual void reset();

  virtual int getChar();

  virtual int lookChar();

  virtual GString *getPSFilter(int psLevel, const char *indent,

             GBool okToReadStream)

    { return NULL; }

  virtual GBool isBinary(GBool last = gTrue);

  virtual GBool isEncoder() { return gTrue; }

private:

  int length;

  int count;

};

//------------------------------------------------------------------------

// ASCIIHexEncoder

//------------------------------------------------------------------------

class ASCIIHexEncoder: public FilterStream {

public:

  ASCIIHexEncoder(Stream *strA);

  virtual ~ASCIIHexEncoder();

  virtual Stream *copy();

  virtual StreamKind getKind() { return strWeird; }

  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(int psLevel, const char *indent,

             GBool okToReadStream)

    { 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 Stream *copy();

  virtual StreamKind getKind() { return strWeird; }

  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(int psLevel, const char *indent,

             GBool okToReadStream)

    { 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 Stream *copy();

  virtual StreamKind getKind() { return strWeird; }

  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(int psLevel, const char *indent,

             GBool okToReadStream)

    { return NULL; }

  virtual GBool isBinary(GBool last = gTrue) { return gTrue; }

  virtual GBool isEncoder() { return gTrue; }

private:

  char buf[131];

  char *bufPtr;

  char *bufEnd;

  char *nextEnd;

  GBool eof;

  GBool fillBuf();

};

//------------------------------------------------------------------------

// LZWEncoder

//------------------------------------------------------------------------

struct LZWEncoderNode {

  int byte;

  LZWEncoderNode *next;   // next sibling

  LZWEncoderNode *children; // first child

};

class LZWEncoder: public FilterStream {

public:

  LZWEncoder(Stream *strA);

  virtual ~LZWEncoder();

  virtual Stream *copy();

  virtual StreamKind getKind() { return strWeird; }

  virtual void reset();

  virtual int getChar();

  virtual int lookChar();

  virtual GString *getPSFilter(int psLevel, const char *indent,

             GBool okToReadStream)

    { return NULL; }

  virtual GBool isBinary(GBool last = gTrue) { return gTrue; }

  virtual GBool isEncoder() { return gTrue; }

private:

  LZWEncoderNode table[4096];

  int nextSeq;

  int codeLen;

  Guchar inBuf[8192];

  int inBufStart;

  int inBufLen;

  int outBuf;

  int outBufLen;

  GBool needEOD;

  void fillBuf();

};

#endif