root/lib/pdf/xpdf/Stream.cc

DEFINITIONS

1. close
2. getRawChar
3. getLine
4. getPSFilter
5. addFilters
6. makeFilter
7. close
8. setPos
9. reset
10. getPixel
11. getLine
12. skipLine
13. lookChar
14. getChar
15. getNextLine
16. makeSubStream
17. reset
18. close
19. fillBuf
20. setPos
21. moveStart
22. makeSubStream
23. reset
24. close
25. setPos
26. moveStart
27. makeSubStream
28. getChar
29. lookChar
30. setPos
31. getStart
32. moveStart
33. reset
34. lookChar
35. getPSFilter
36. isBinary
37. reset
38. lookChar
39. getPSFilter
40. isBinary
41. getChar
42. lookChar
43. getRawChar
44. reset
45. processNextCode
46. clearTable
47. getCode
48. getPSFilter
49. isBinary
50. reset
51. getPSFilter
52. isBinary
53. fillBuf
54. reset
55. addPixels
56. addPixelsNeg
57. lookChar
58. getTwoDimCode
59. getWhiteCode
60. getBlackCode
61. lookBits
62. getPSFilter
63. isBinary
64. reset
65. close
66. getChar
67. lookChar
68. restart
69. readMCURow
70. readScan
71. readDataUnit
72. readProgressiveDataUnit
73. decodeImage
74. transformDataUnit
75. readHuffSym
76. readAmp
77. readBit
78. readHeader
79. readBaselineSOF
80. readProgressiveSOF
81. readScanInfo
82. readQuantTables
83. readHuffmanTables
84. readRestartInterval
85. readJFIFMarker
86. readAdobeMarker
87. readTrailer
88. readMarker
89. read16
90. getPSFilter
91. isBinary
92. reset
93. getChar
94. lookChar
95. getRawChar
96. getPSFilter
97. isBinary
98. readSome
99. startBlock
100. loadFixedCodes
101. readDynamicCodes
102. compHuffmanCodes
103. getHuffmanCodeWord
104. getCodeWord
105. reset
106. getChar
107. lookChar
108. isBinary
109. reset
110. fillBuf
111. reset
112. fillBuf
113. reset
114. fillBuf

//========================================================================
//
// Stream.cc
//
// Copyright 1996-2003 Glyph & Cog, LLC
//
//========================================================================

#include <aconf.h>

#ifdef USE_GCC_PRAGMAS
#pragma implementation
#endif

#include <stdio.h>
#include <stdlib.h>
#include <stddef.h>
#include <limits.h>
#ifndef WIN32
#include <unistd.h>
#else
extern "C" int unlink(char *filename);
#endif
#include <string.h>
#include <ctype.h>
#include "gmem.h"
#include "gfile.h"
#include "config.h"
#include "Error.h"
#include "Object.h"
#include "Lexer.h"
#include "GfxState.h"
#include "Stream.h"
#include "JBIG2Stream.h"
#include "JPXStream.h"
#include "Stream-CCITT.h"

#ifdef __DJGPP__
static GBool setDJSYSFLAGS = gFalse;
#endif

#ifdef VMS
#ifdef __GNUC__
#define SEEK_SET 0
#define SEEK_CUR 1
#define SEEK_END 2
#endif
#endif

//------------------------------------------------------------------------
// Stream (base class)
//------------------------------------------------------------------------

Stream::Stream() {
  ref = 1;
}

Stream::~Stream() {
}

void Stream::close() {
}

int Stream::getRawChar() {
  error(-1, "Internal: called getRawChar() on non-predictor stream");
  return EOF;
}

char *Stream::getLine(char *buf, int size) {
  int i;
  int c;

  if (lookChar() == EOF)
    return NULL;
  for (i = 0; i < size - 1; ++i) {
    c = getChar();
    if (c == EOF || c == '\n')
      break;
    if (c == '\r') {
      if ((c = lookChar()) == '\n')
        getChar();
      break;
    }
    buf[i] = c;
  }
  buf[i] = '\0';
  return buf;
}

GString *Stream::getPSFilter(int psLevel, char *indent) {
  return new GString();
}

Stream *Stream::addFilters(Object *dict) {
  Object obj, obj2;
  Object params, params2;
  Stream *str;
  int i;

  str = this;
  dict->dictLookup("Filter", &obj);
  if (obj.isNull()) {
    obj.free();
    dict->dictLookup("F", &obj);
  }
  dict->dictLookup("DecodeParms", &params);
  if (params.isNull()) {
    params.free();
    dict->dictLookup("DP", &params);
  }
  if (obj.isName()) {
    str = makeFilter(obj.getName(), str, &params);
  } else if (obj.isArray()) {
    for (i = 0; i < obj.arrayGetLength(); ++i) {
      obj.arrayGet(i, &obj2);
      if (params.isArray())
        params.arrayGet(i, &params2);
      else
        params2.initNull();
      if (obj2.isName()) {
        str = makeFilter(obj2.getName(), str, &params2);
      } else {
        error(getPos(), "Bad filter name");
        str = new EOFStream(str);
      }
      obj2.free();
      params2.free();
    }
  } else if (!obj.isNull()) {
    error(getPos(), "Bad 'Filter' attribute in stream");
  }
  obj.free();
  params.free();

  return str;
}

Stream *Stream::makeFilter(char *name, Stream *str, Object *params) {
  int pred;                     // parameters
  int colors;
  int bits;
  int early;
  int encoding;
  GBool endOfLine, byteAlign, endOfBlock, black;
  int columns, rows;
  int colorXform;
  Object globals, obj;

  if (!strcmp(name, "ASCIIHexDecode") || !strcmp(name, "AHx")) {
    str = new ASCIIHexStream(str);
  } else if (!strcmp(name, "ASCII85Decode") || !strcmp(name, "A85")) {
    str = new ASCII85Stream(str);
  } else if (!strcmp(name, "LZWDecode") || !strcmp(name, "LZW")) {
    pred = 1;
    columns = 1;
    colors = 1;
    bits = 8;
    early = 1;
    if (params->isDict()) {
      params->dictLookup("Predictor", &obj);
      if (obj.isInt())
        pred = obj.getInt();
      obj.free();
      params->dictLookup("Columns", &obj);
      if (obj.isInt())
        columns = obj.getInt();
      obj.free();
      params->dictLookup("Colors", &obj);
      if (obj.isInt())
        colors = obj.getInt();
      obj.free();
      params->dictLookup("BitsPerComponent", &obj);
      if (obj.isInt())
        bits = obj.getInt();
      obj.free();
      params->dictLookup("EarlyChange", &obj);
      if (obj.isInt())
        early = obj.getInt();
      obj.free();
    }
    str = new LZWStream(str, pred, columns, colors, bits, early);
  } else if (!strcmp(name, "RunLengthDecode") || !strcmp(name, "RL")) {
    str = new RunLengthStream(str);
  } else if (!strcmp(name, "CCITTFaxDecode") || !strcmp(name, "CCF")) {
    encoding = 0;
    endOfLine = gFalse;
    byteAlign = gFalse;
    columns = 1728;
    rows = 0;
    endOfBlock = gTrue;
    black = gFalse;
    if (params->isDict()) {
      params->dictLookup("K", &obj);
      if (obj.isInt()) {
        encoding = obj.getInt();
      }
      obj.free();
      params->dictLookup("EndOfLine", &obj);
      if (obj.isBool()) {
        endOfLine = obj.getBool();
      }
      obj.free();
      params->dictLookup("EncodedByteAlign", &obj);
      if (obj.isBool()) {
        byteAlign = obj.getBool();
      }
      obj.free();
      params->dictLookup("Columns", &obj);
      if (obj.isInt()) {
        columns = obj.getInt();
      }
      obj.free();
      params->dictLookup("Rows", &obj);
      if (obj.isInt()) {
        rows = obj.getInt();
      }
      obj.free();
      params->dictLookup("EndOfBlock", &obj);
      if (obj.isBool()) {
        endOfBlock = obj.getBool();
      }
      obj.free();
      params->dictLookup("BlackIs1", &obj);
      if (obj.isBool()) {
        black = obj.getBool();
      }
      obj.free();
    }
    str = new CCITTFaxStream(str, encoding, endOfLine, byteAlign,
                             columns, rows, endOfBlock, black);
  } else if (!strcmp(name, "DCTDecode") || !strcmp(name, "DCT")) {
    colorXform = -1;
    if (params->isDict()) {
      if (params->dictLookup("ColorTransform", &obj)->isInt()) {
        colorXform = obj.getInt();
      }
      obj.free();
    }
    str = new DCTStream(str, colorXform);
  } else if (!strcmp(name, "FlateDecode") || !strcmp(name, "Fl")) {
    pred = 1;
    columns = 1;
    colors = 1;
    bits = 8;
    if (params->isDict()) {
      params->dictLookup("Predictor", &obj);
      if (obj.isInt())
        pred = obj.getInt();
      obj.free();
      params->dictLookup("Columns", &obj);
      if (obj.isInt())
        columns = obj.getInt();
      obj.free();
      params->dictLookup("Colors", &obj);
      if (obj.isInt())
        colors = obj.getInt();
      obj.free();
      params->dictLookup("BitsPerComponent", &obj);
      if (obj.isInt())
        bits = obj.getInt();
      obj.free();
    }
    str = new FlateStream(str, pred, columns, colors, bits);
  } else if (!strcmp(name, "JBIG2Decode")) {
    if (params->isDict()) {
      params->dictLookup("JBIG2Globals", &globals);
    }
    str = new JBIG2Stream(str, &globals);
    globals.free();
  } else if (!strcmp(name, "JPXDecode")) {
    str = new JPXStream(str);
  } else {
    error(getPos(), "Unknown filter '%s'", name);
    str = new EOFStream(str);
  }
  return str;
}

//------------------------------------------------------------------------
// BaseStream
//------------------------------------------------------------------------

BaseStream::BaseStream(Object *dictA) {
  dict = *dictA;
}

BaseStream::~BaseStream() {
  dict.free();
}

//------------------------------------------------------------------------
// FilterStream
//------------------------------------------------------------------------

FilterStream::FilterStream(Stream *strA) {
  str = strA;
}

FilterStream::~FilterStream() {
}

void FilterStream::close() {
  str->close();
}

void FilterStream::setPos(Guint pos, int dir) {
  error(-1, "Internal: called setPos() on FilterStream");
}

//------------------------------------------------------------------------
// ImageStream
//------------------------------------------------------------------------

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

  str = strA;
  width = widthA;
  nComps = nCompsA;
  nBits = nBitsA;

  nVals = width * nComps;
  if (nBits == 1) {
    imgLineSize = (nVals + 7) & ~7;
  } else {
    imgLineSize = nVals;
  }
  imgLine = (Guchar *)gmallocn(imgLineSize, sizeof(Guchar));
  imgIdx = nVals;
}

ImageStream::~ImageStream() {
  gfree(imgLine);
}

void ImageStream::reset() {
  str->reset();
}

GBool ImageStream::getPixel(Guchar *pix) {
  int i;

  if (imgIdx >= nVals) {
    getLine();
    imgIdx = 0;
  }
  for (i = 0; i < nComps; ++i) {
    pix[i] = imgLine[imgIdx++];
  }
  return gTrue;
}

Guchar *ImageStream::getLine() {
  Gulong buf, bitMask;
  int bits;
  int c;
  int i;

  if (nBits == 1) {
    for (i = 0; i < nVals; i += 8) {
      c = str->getChar();
      imgLine[i+0] = (Guchar)((c >> 7) & 1);
      imgLine[i+1] = (Guchar)((c >> 6) & 1);
      imgLine[i+2] = (Guchar)((c >> 5) & 1);
      imgLine[i+3] = (Guchar)((c >> 4) & 1);
      imgLine[i+4] = (Guchar)((c >> 3) & 1);
      imgLine[i+5] = (Guchar)((c >> 2) & 1);
      imgLine[i+6] = (Guchar)((c >> 1) & 1);
      imgLine[i+7] = (Guchar)(c & 1);
    }
  } else if (nBits == 8) {
    for (i = 0; i < nVals; ++i) {
      imgLine[i] = str->getChar();
    }
  } else {
    bitMask = (1 << nBits) - 1;
    buf = 0;
    bits = 0;
    for (i = 0; i < nVals; ++i) {
      if (bits < nBits) {
        buf = (buf << 8) | (str->getChar() & 0xff);
        bits += 8;
      }
      imgLine[i] = (Guchar)((buf >> (bits - nBits)) & bitMask);
      bits -= nBits;
    }
  }
  return imgLine;
}

void ImageStream::skipLine() {
  int n, i;

  n = (nVals * nBits + 7) >> 3;
  for (i = 0; i < n; ++i) {
    str->getChar();
  }
}

//------------------------------------------------------------------------
// StreamPredictor
//------------------------------------------------------------------------

StreamPredictor::StreamPredictor(Stream *strA, int predictorA,
                                 int widthA, int nCompsA, int nBitsA) {
  str = strA;
  predictor = predictorA;
  width = widthA;
  nComps = nCompsA;
  nBits = nBitsA;
  predLine = NULL;
  ok = gFalse;

  nVals = width * nComps;
  pixBytes = (nComps * nBits + 7) >> 3;
  rowBytes = ((nVals * nBits + 7) >> 3) + pixBytes;
  if (width <= 0 || nComps <= 0 || nBits <= 0 ||
      nComps > gfxColorMaxComps ||
      nBits > 16 ||
      width >= INT_MAX / nComps ||      // check for overflow in nVals 
      nVals >= (INT_MAX - 7) / nBits) { // check for overflow in rowBytes
    return;
  }
  predLine = (Guchar *)gmalloc(rowBytes);
  memset(predLine, 0, rowBytes);
  predIdx = rowBytes;

  ok = gTrue;
}

StreamPredictor::~StreamPredictor() {
  gfree(predLine);
}

int StreamPredictor::lookChar() {
  if (predIdx >= rowBytes) {
    if (!getNextLine()) {
      return EOF;
    }
  }
  return predLine[predIdx];
}

int StreamPredictor::getChar() {
  if (predIdx >= rowBytes) {
    if (!getNextLine()) {
      return EOF;
    }
  }
  return predLine[predIdx++];
}

GBool StreamPredictor::getNextLine() {
  int curPred;
  Guchar upLeftBuf[gfxColorMaxComps * 2 + 1];
  int left, up, upLeft, p, pa, pb, pc;
  int c;
  Gulong inBuf, outBuf, bitMask;
  int inBits, outBits;
  int i, j, k, kk;

  // get PNG optimum predictor number
  if (predictor >= 10) {
    if ((curPred = str->getRawChar()) == EOF) {
      return gFalse;
    }
    curPred += 10;
  } else {
    curPred = predictor;
  }

  // read the raw line, apply PNG (byte) predictor
  memset(upLeftBuf, 0, pixBytes + 1);
  for (i = pixBytes; i < rowBytes; ++i) {
    for (j = pixBytes; j > 0; --j) {
      upLeftBuf[j] = upLeftBuf[j-1];
    }
    upLeftBuf[0] = predLine[i];
    if ((c = str->getRawChar()) == EOF) {
      if (i > pixBytes) {
        // this ought to return false, but some (broken) PDF files
        // contain truncated image data, and Adobe apparently reads the
        // last partial line
        break;
      }
      return gFalse;
    }
    switch (curPred) {
    case 11:                    // PNG sub
      predLine[i] = predLine[i - pixBytes] + (Guchar)c;
      break;
    case 12:                    // PNG up
      predLine[i] = predLine[i] + (Guchar)c;
      break;
    case 13:                    // PNG average
      predLine[i] = ((predLine[i - pixBytes] + predLine[i]) >> 1) +
                    (Guchar)c;
      break;
    case 14:                    // PNG Paeth
      left = predLine[i - pixBytes];
      up = predLine[i];
      upLeft = upLeftBuf[pixBytes];
      p = left + up - upLeft;
      if ((pa = p - left) < 0)
        pa = -pa;
      if ((pb = p - up) < 0)
        pb = -pb;
      if ((pc = p - upLeft) < 0)
        pc = -pc;
      if (pa <= pb && pa <= pc)
        predLine[i] = left + (Guchar)c;
      else if (pb <= pc)
        predLine[i] = up + (Guchar)c;
      else
        predLine[i] = upLeft + (Guchar)c;
      break;
    case 10:                    // PNG none
    default:                    // no predictor or TIFF predictor
      predLine[i] = (Guchar)c;
      break;
    }
  }

  // apply TIFF (component) predictor
  if (predictor == 2) {
    if (nBits == 1) {
      inBuf = predLine[pixBytes - 1];
      for (i = pixBytes; i < rowBytes; i += 8) {
        // 1-bit add is just xor
        inBuf = (inBuf << 8) | predLine[i];
        predLine[i] ^= inBuf >> nComps;
      }
    } else if (nBits == 8) {
      for (i = pixBytes; i < rowBytes; ++i) {
        predLine[i] += predLine[i - nComps];
      }
    } else {
      memset(upLeftBuf, 0, nComps + 1);
      bitMask = (1 << nBits) - 1;
      inBuf = outBuf = 0;
      inBits = outBits = 0;
      j = k = pixBytes;
      for (i = 0; i < width; ++i) {
        for (kk = 0; kk < nComps; ++kk) {
          if (inBits < nBits) {
            inBuf = (inBuf << 8) | (predLine[j++] & 0xff);
            inBits += 8;
          }
          upLeftBuf[kk] = (Guchar)((upLeftBuf[kk] +
                                    (inBuf >> (inBits - nBits))) & bitMask);
          inBits -= nBits;
          outBuf = (outBuf << nBits) | upLeftBuf[kk];
          outBits += nBits;
          if (outBits >= 8) {
            predLine[k++] = (Guchar)(outBuf >> (outBits - 8));
            outBits -= 8;
          }
        }
      }
      if (outBits > 0) {
        predLine[k++] = (Guchar)((outBuf << (8 - outBits)) +
                                 (inBuf & ((1 << (8 - outBits)) - 1)));
      }
    }
  }

  // reset to start of line
  predIdx = pixBytes;

  return gTrue;
}

//------------------------------------------------------------------------
// FileStream
//------------------------------------------------------------------------

FileStream::FileStream(FILE *fA, Guint startA, GBool limitedA,
                       Guint lengthA, Object *dictA):
    BaseStream(dictA) {
  f = fA;
  start = startA;
  limited = limitedA;
  length = lengthA;
  bufPtr = bufEnd = buf;
  bufPos = start;
  savePos = 0;
  saved = gFalse;
}

FileStream::~FileStream() {
  close();
}

Stream *FileStream::makeSubStream(Guint startA, GBool limitedA,
                                  Guint lengthA, Object *dictA) {
  return new FileStream(f, startA, limitedA, lengthA, dictA);
}

void FileStream::reset() {
#if HAVE_FSEEKO
  savePos = (Guint)ftello(f);
  fseeko(f, start, SEEK_SET);
#elif HAVE_FSEEK64
  savePos = (Guint)ftell64(f);
  fseek64(f, start, SEEK_SET);
#else
  savePos = (Guint)ftell(f);
  fseek(f, start, SEEK_SET);
#endif
  saved = gTrue;
  bufPtr = bufEnd = buf;
  bufPos = start;
}

void FileStream::close() {
  if (saved) {
#if HAVE_FSEEKO
    fseeko(f, savePos, SEEK_SET);
#elif HAVE_FSEEK64
    fseek64(f, savePos, SEEK_SET);
#else
    fseek(f, savePos, SEEK_SET);
#endif
    saved = gFalse;
  }
}

GBool FileStream::fillBuf() {
  int n;

  bufPos += bufEnd - buf;
  bufPtr = bufEnd = buf;
  if (limited && bufPos >= start + length) {
    return gFalse;
  }
  if (limited && bufPos + fileStreamBufSize > start + length) {
    n = start + length - bufPos;
  } else {
    n = fileStreamBufSize;
  }
  n = fread(buf, 1, n, f);
  bufEnd = buf + n;
  if (bufPtr >= bufEnd) {
    return gFalse;
  }
  return gTrue;
}

void FileStream::setPos(Guint pos, int dir) {
  Guint size;

  if (dir >= 0) {
#if HAVE_FSEEKO
    fseeko(f, pos, SEEK_SET);
#elif HAVE_FSEEK64
    fseek64(f, pos, SEEK_SET);
#else
    fseek(f, pos, SEEK_SET);
#endif
    bufPos = pos;
  } else {
#if HAVE_FSEEKO
    fseeko(f, 0, SEEK_END);
    size = (Guint)ftello(f);
#elif HAVE_FSEEK64
    fseek64(f, 0, SEEK_END);
    size = (Guint)ftell64(f);
#else
    fseek(f, 0, SEEK_END);
    size = (Guint)ftell(f);
#endif
    if (pos > size)
      pos = (Guint)size;
#ifdef __CYGWIN32__
    //~ work around a bug in cygwin's implementation of fseek
    rewind(f);
#endif
#if HAVE_FSEEKO
    fseeko(f, -(int)pos, SEEK_END);
    bufPos = (Guint)ftello(f);
#elif HAVE_FSEEK64
    fseek64(f, -(int)pos, SEEK_END);
    bufPos = (Guint)ftell64(f);
#else
    fseek(f, -(int)pos, SEEK_END);
    bufPos = (Guint)ftell(f);
#endif
  }
  bufPtr = bufEnd = buf;
}

void FileStream::moveStart(int delta) {
  start += delta;
  bufPtr = bufEnd = buf;
  bufPos = start;
}

//------------------------------------------------------------------------
// MemStream
//------------------------------------------------------------------------

MemStream::MemStream(char *bufA, Guint startA, Guint lengthA, Object *dictA):
    BaseStream(dictA) {
  buf = bufA;
  start = startA;
  length = lengthA;
  bufEnd = buf + start + length;
  bufPtr = buf + start;
  needFree = gFalse;
}

MemStream::~MemStream() {
  if (needFree) {
    gfree(buf);
  }
}

Stream *MemStream::makeSubStream(Guint startA, GBool limited,
                                 Guint lengthA, Object *dictA) {
  MemStream *subStr;
  Guint newLength;

  if (!limited || startA + lengthA > start + length) {
    newLength = start + length - startA;
  } else {
    newLength = lengthA;
  }
  subStr = new MemStream(buf, startA, newLength, dictA);
  return subStr;
}

void MemStream::reset() {
  bufPtr = buf + start;
}

void MemStream::close() {
}

void MemStream::setPos(Guint pos, int dir) {
  Guint i;

  if (dir >= 0) {
    i = pos;
  } else {
    i = start + length - pos;
  }
  if (i < start) {
    i = start;
  } else if (i > start + length) {
    i = start + length;
  }
  bufPtr = buf + i;
}

void MemStream::moveStart(int delta) {
  start += delta;
  length -= delta;
  bufPtr = buf + start;
}

//------------------------------------------------------------------------
// EmbedStream
//------------------------------------------------------------------------

EmbedStream::EmbedStream(Stream *strA, Object *dictA,
                         GBool limitedA, Guint lengthA):
    BaseStream(dictA) {
  str = strA;
  limited = limitedA;
  length = lengthA;
}

EmbedStream::~EmbedStream() {
}

Stream *EmbedStream::makeSubStream(Guint start, GBool limitedA,
                                   Guint lengthA, Object *dictA) {
  error(-1, "Internal: called makeSubStream() on EmbedStream");
  return NULL;
}

int EmbedStream::getChar() {
  if (limited && !length) {
    return EOF;
  }
  --length;
  return str->getChar();
}

int EmbedStream::lookChar() {
  if (limited && !length) {
    return EOF;
  }
  return str->lookChar();
}

void EmbedStream::setPos(Guint pos, int dir) {
  error(-1, "Internal: called setPos() on EmbedStream");
}

Guint EmbedStream::getStart() {
  error(-1, "Internal: called getStart() on EmbedStream");
  return 0;
}

void EmbedStream::moveStart(int delta) {
  error(-1, "Internal: called moveStart() on EmbedStream");
}

//------------------------------------------------------------------------
// ASCIIHexStream
//------------------------------------------------------------------------

ASCIIHexStream::ASCIIHexStream(Stream *strA):
    FilterStream(strA) {
  buf = EOF;
  eof = gFalse;
}

ASCIIHexStream::~ASCIIHexStream() {
  delete str;
}

void ASCIIHexStream::reset() {
  str->reset();
  buf = EOF;
  eof = gFalse;
}

int ASCIIHexStream::lookChar() {
  int c1, c2, x;

  if (buf != EOF)
    return buf;
  if (eof) {
    buf = EOF;
    return EOF;
  }
  do {
    c1 = str->getChar();
  } while (isspace(c1));
  if (c1 == '>') {
    eof = gTrue;
    buf = EOF;
    return buf;
  }
  do {
    c2 = str->getChar();
  } while (isspace(c2));
  if (c2 == '>') {
    eof = gTrue;
    c2 = '0';
  }
  if (c1 >= '0' && c1 <= '9') {
    x = (c1 - '0') << 4;
  } else if (c1 >= 'A' && c1 <= 'F') {
    x = (c1 - 'A' + 10) << 4;
  } else if (c1 >= 'a' && c1 <= 'f') {
    x = (c1 - 'a' + 10) << 4;
  } else if (c1 == EOF) {
    eof = gTrue;
    x = 0;
  } else {
    error(getPos(), "Illegal character <%02x> in ASCIIHex stream", c1);
    x = 0;
  }
  if (c2 >= '0' && c2 <= '9') {
    x += c2 - '0';
  } else if (c2 >= 'A' && c2 <= 'F') {
    x += c2 - 'A' + 10;
  } else if (c2 >= 'a' && c2 <= 'f') {
    x += c2 - 'a' + 10;
  } else if (c2 == EOF) {
    eof = gTrue;
    x = 0;
  } else {
    error(getPos(), "Illegal character <%02x> in ASCIIHex stream", c2);
  }
  buf = x & 0xff;
  return buf;
}

GString *ASCIIHexStream::getPSFilter(int psLevel, char *indent) {
  GString *s;

  if (psLevel < 2) {
    return NULL;
  }
  if (!(s = str->getPSFilter(psLevel, indent))) {
    return NULL;
  }
  s->append(indent)->append("/ASCIIHexDecode filter\n");
  return s;
}

GBool ASCIIHexStream::isBinary(GBool last) {
  return str->isBinary(gFalse);
}

//------------------------------------------------------------------------
// ASCII85Stream
//------------------------------------------------------------------------

ASCII85Stream::ASCII85Stream(Stream *strA):
    FilterStream(strA) {
  index = n = 0;
  eof = gFalse;
}

ASCII85Stream::~ASCII85Stream() {
  delete str;
}

void ASCII85Stream::reset() {
  str->reset();
  index = n = 0;
  eof = gFalse;
}

int ASCII85Stream::lookChar() {
  int k;
  Gulong t;

  if (index >= n) {
    if (eof)
      return EOF;
    index = 0;
    do {
      c[0] = str->getChar();
    } while (Lexer::isSpace(c[0]));
    if (c[0] == '~' || c[0] == EOF) {
      eof = gTrue;
      n = 0;
      return EOF;
    } else if (c[0] == 'z') {
      b[0] = b[1] = b[2] = b[3] = 0;
      n = 4;
    } else {
      for (k = 1; k < 5; ++k) {
        do {
          c[k] = str->getChar();
        } while (Lexer::isSpace(c[k]));
        if (c[k] == '~' || c[k] == EOF)
          break;
      }
      n = k - 1;
      if (k < 5 && (c[k] == '~' || c[k] == EOF)) {
        for (++k; k < 5; ++k)
          c[k] = 0x21 + 84;
        eof = gTrue;
      }
      t = 0;
      for (k = 0; k < 5; ++k)
        t = t * 85 + (c[k] - 0x21);
      for (k = 3; k >= 0; --k) {
        b[k] = (int)(t & 0xff);
        t >>= 8;
      }
    }
  }
  return b[index];
}

GString *ASCII85Stream::getPSFilter(int psLevel, char *indent) {
  GString *s;

  if (psLevel < 2) {
    return NULL;
  }
  if (!(s = str->getPSFilter(psLevel, indent))) {
    return NULL;
  }
  s->append(indent)->append("/ASCII85Decode filter\n");
  return s;
}

GBool ASCII85Stream::isBinary(GBool last) {
  return str->isBinary(gFalse);
}

//------------------------------------------------------------------------
// LZWStream
//------------------------------------------------------------------------

LZWStream::LZWStream(Stream *strA, int predictor, int columns, int colors,
                     int bits, int earlyA):
    FilterStream(strA) {
  if (predictor != 1) {
    pred = new StreamPredictor(this, predictor, columns, colors, bits);
    if (!pred->isOk()) {
      delete pred;
      pred = NULL;
    }
  } else {
    pred = NULL;
  }
  early = earlyA;
  eof = gFalse;
  inputBits = 0;
  clearTable();
}

LZWStream::~LZWStream() {
  if (pred) {
    delete pred;
  }
  delete str;
}

int LZWStream::getChar() {
  if (pred) {
    return pred->getChar();
  }
  if (eof) {
    return EOF;
  }
  if (seqIndex >= seqLength) {
    if (!processNextCode()) {
      return EOF;
    }
  }
  return seqBuf[seqIndex++];
}

int LZWStream::lookChar() {
  if (pred) {
    return pred->lookChar();
  }
  if (eof) {
    return EOF;
  }
  if (seqIndex >= seqLength) {
    if (!processNextCode()) {
      return EOF;
    }
  }
  return seqBuf[seqIndex];
}

int LZWStream::getRawChar() {
  if (eof) {
    return EOF;
  }
  if (seqIndex >= seqLength) {
    if (!processNextCode()) {
      return EOF;
    }
  }
  return seqBuf[seqIndex++];
}

void LZWStream::reset() {
  str->reset();
  eof = gFalse;
  inputBits = 0;
  clearTable();
}

GBool LZWStream::processNextCode() {
  int code;
  int nextLength;
  int i, j;

  // check for EOF
  if (eof) {
    return gFalse;
  }

  // check for eod and clear-table codes
 start:
  code = getCode();
  if (code == EOF || code == 257) {
    eof = gTrue;
    return gFalse;
  }
  if (code == 256) {
    clearTable();
    goto start;
  }
  if (nextCode >= 4097) {
    error(getPos(), "Bad LZW stream - expected clear-table code");
    clearTable();
  }

  // process the next code
  nextLength = seqLength + 1;
  if (code < 256) {
    seqBuf[0] = code;
    seqLength = 1;
  } else if (code < nextCode) {
    seqLength = table[code].length;
    for (i = seqLength - 1, j = code; i > 0; --i) {
      seqBuf[i] = table[j].tail;
      j = table[j].head;
    }
    seqBuf[0] = j;
  } else if (code == nextCode) {
    seqBuf[seqLength] = newChar;
    ++seqLength;
  } else {
    error(getPos(), "Bad LZW stream - unexpected code");
    eof = gTrue;
    return gFalse;
  }
  newChar = seqBuf[0];
  if (first) {
    first = gFalse;
  } else {
    table[nextCode].length = nextLength;
    table[nextCode].head = prevCode;
    table[nextCode].tail = newChar;
    ++nextCode;
    if (nextCode + early == 512)
      nextBits = 10;
    else if (nextCode + early == 1024)
      nextBits = 11;
    else if (nextCode + early == 2048)
      nextBits = 12;
  }
  prevCode = code;

  // reset buffer
  seqIndex = 0;

  return gTrue;
}

void LZWStream::clearTable() {
  nextCode = 258;
  nextBits = 9;
  seqIndex = seqLength = 0;
  first = gTrue;
}

int LZWStream::getCode() {
  int c;
  int code;

  while (inputBits < nextBits) {
    if ((c = str->getChar()) == EOF)
      return EOF;
    inputBuf = (inputBuf << 8) | (c & 0xff);
    inputBits += 8;
  }
  code = (inputBuf >> (inputBits - nextBits)) & ((1 << nextBits) - 1);
  inputBits -= nextBits;
  return code;
}

GString *LZWStream::getPSFilter(int psLevel, char *indent) {
  GString *s;

  if (psLevel < 2 || pred) {
    return NULL;
  }
  if (!(s = str->getPSFilter(psLevel, indent))) {
    return NULL;
  }
  s->append(indent)->append("<< ");
  if (!early) {
    s->append("/EarlyChange 0 ");
  }
  s->append(">> /LZWDecode filter\n");
  return s;
}

GBool LZWStream::isBinary(GBool last) {
  return str->isBinary(gTrue);
}

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

RunLengthStream::RunLengthStream(Stream *strA):
    FilterStream(strA) {
  bufPtr = bufEnd = buf;
  eof = gFalse;
}

RunLengthStream::~RunLengthStream() {
  delete str;
}

void RunLengthStream::reset() {
  str->reset();
  bufPtr = bufEnd = buf;
  eof = gFalse;
}

GString *RunLengthStream::getPSFilter(int psLevel, char *indent) {
  GString *s;

  if (psLevel < 2) {
    return NULL;
  }
  if (!(s = str->getPSFilter(psLevel, indent))) {
    return NULL;
  }
  s->append(indent)->append("/RunLengthDecode filter\n");
  return s;
}

GBool RunLengthStream::isBinary(GBool last) {
  return str->isBinary(gTrue);
}

GBool RunLengthStream::fillBuf() {
  int c;
  int n, i;

  if (eof)
    return gFalse;
  c = str->getChar();
  if (c == 0x80 || c == EOF) {
    eof = gTrue;
    return gFalse;
  }
  if (c < 0x80) {
    n = c + 1;
    for (i = 0; i < n; ++i)
      buf[i] = (char)str->getChar();
  } else {
    n = 0x101 - c;
    c = str->getChar();
    for (i = 0; i < n; ++i)
      buf[i] = (char)c;
  }
  bufPtr = buf;
  bufEnd = buf + n;
  return gTrue;
}

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

CCITTFaxStream::CCITTFaxStream(Stream *strA, int encodingA, GBool endOfLineA,
                               GBool byteAlignA, int columnsA, int rowsA,
                               GBool endOfBlockA, GBool blackA):
    FilterStream(strA) {
  encoding = encodingA;
  endOfLine = endOfLineA;
  byteAlign = byteAlignA;
  columns = columnsA;
  if (columns < 1) {
    columns = 1;
  } else if (columns > INT_MAX - 2) {
    columns = INT_MAX - 2;
  }
  rows = rowsA;
  endOfBlock = endOfBlockA;
  black = blackA;
  // 0 <= codingLine[0] < codingLine[1] < ... < codingLine[n] = columns
  // ---> max codingLine size = columns + 1
  // refLine has one extra guard entry at the end
  // ---> max refLine size = columns + 2
  codingLine = (int *)gmallocn(columns + 1, sizeof(int));
  refLine = (int *)gmallocn(columns + 2, sizeof(int));

  eof = gFalse;
  row = 0;
  nextLine2D = encoding < 0;
  inputBits = 0;
  codingLine[0] = columns;
  a0i = 0;
  outputBits = 0;

  buf = EOF;
}

CCITTFaxStream::~CCITTFaxStream() {
  delete str;
  gfree(refLine);
  gfree(codingLine);
}

void CCITTFaxStream::reset() {
  short code1;

  str->reset();
  eof = gFalse;
  row = 0;
  nextLine2D = encoding < 0;
  inputBits = 0;
  codingLine[0] = columns;
  a0i = 0;
  outputBits = 0;
  buf = EOF;

  // skip any initial zero bits and end-of-line marker, and get the 2D
  // encoding tag
  while ((code1 = lookBits(12)) == 0) {
    eatBits(1);
  }
  if (code1 == 0x001) {
    eatBits(12);
  }
  if (encoding > 0) {
    nextLine2D = !lookBits(1);
    eatBits(1);
  }
}

inline void CCITTFaxStream::addPixels(int a1, int blackPixels) {
  if (a1 > codingLine[a0i]) {
    if (a1 > columns) {
      error(getPos(), "CCITTFax row is wrong length (%d)", a1);
      err = gTrue;
      a1 = columns;
    }
    if ((a0i & 1) ^ blackPixels) {
      ++a0i;
    }
    codingLine[a0i] = a1;
  }
}

inline void CCITTFaxStream::addPixelsNeg(int a1, int blackPixels) {
  if (a1 > codingLine[a0i]) {
    if (a1 > columns) {
      error(getPos(), "CCITTFax row is wrong length (%d)", a1);
      err = gTrue;
      a1 = columns;
    }
    if ((a0i & 1) ^ blackPixels) {
      ++a0i;
    }
    codingLine[a0i] = a1;
  } else if (a1 < codingLine[a0i]) {
    if (a1 < 0) {
      error(getPos(), "Invalid CCITTFax code");
      err = gTrue;
      a1 = 0;
    }
    while (a0i > 0 && a1 <= codingLine[a0i - 1]) {
      --a0i;
    }
    codingLine[a0i] = a1;
  }
}

int CCITTFaxStream::lookChar() {
  short code1, code2, code3;
  int b1i, blackPixels, i, bits;
  GBool gotEOL;

  if (buf != EOF) {
    return buf;
  }

  // read the next row
  if (outputBits == 0) {

    // if at eof just return EOF
    if (eof) {
      return EOF;
    }

    err = gFalse;

    // 2-D encoding
    if (nextLine2D) {
      for (i = 0; codingLine[i] < columns; ++i) {
        refLine[i] = codingLine[i];
      }
      refLine[i++] = columns;
      refLine[i] = columns;
      codingLine[0] = 0;
      a0i = 0;
      b1i = 0;
      blackPixels = 0;
      // invariant:
      // refLine[b1i-1] <= codingLine[a0i] < refLine[b1i] < refLine[b1i+1]
      //                                                             <= columns
      // exception at left edge:
      //   codingLine[a0i = 0] = refLine[b1i = 0] = 0 is possible
      // exception at right edge:
      //   refLine[b1i] = refLine[b1i+1] = columns is possible
      while (codingLine[a0i] < columns) {
        code1 = getTwoDimCode();
        switch (code1) {
        case twoDimPass:
          addPixels(refLine[b1i + 1], blackPixels);
          if (refLine[b1i + 1] < columns) {
            b1i += 2;
          }
          break;
        case twoDimHoriz:
          code1 = code2 = 0;
          if (blackPixels) {
            do {
              code1 += code3 = getBlackCode();
            } while (code3 >= 64);
            do {
              code2 += code3 = getWhiteCode();
            } while (code3 >= 64);
          } else {
            do {
              code1 += code3 = getWhiteCode();
            } while (code3 >= 64);
            do {
              code2 += code3 = getBlackCode();
            } while (code3 >= 64);
          }
          addPixels(codingLine[a0i] + code1, blackPixels);
          if (codingLine[a0i] < columns) {
            addPixels(codingLine[a0i] + code2, blackPixels ^ 1);
          }
          while (refLine[b1i] <= codingLine[a0i] && refLine[b1i] < columns) {
            b1i += 2;
          }
          break;
        case twoDimVertR3:
          addPixels(refLine[b1i] + 3, blackPixels);
          blackPixels ^= 1;
          if (codingLine[a0i] < columns) {
            ++b1i;
            while (refLine[b1i] <= codingLine[a0i] && refLine[b1i] < columns) {
              b1i += 2;
            }
          }
          break;
        case twoDimVertR2:
          addPixels(refLine[b1i] + 2, blackPixels);
          blackPixels ^= 1;
          if (codingLine[a0i] < columns) {
            ++b1i;
            while (refLine[b1i] <= codingLine[a0i] && refLine[b1i] < columns) {
              b1i += 2;
            }
          }
          break;
        case twoDimVertR1:
          addPixels(refLine[b1i] + 1, blackPixels);
          blackPixels ^= 1;
          if (codingLine[a0i] < columns) {
            ++b1i;
            while (refLine[b1i] <= codingLine[a0i] && refLine[b1i] < columns) {
              b1i += 2;
            }
          }
          break;
        case twoDimVert0:
          addPixels(refLine[b1i], blackPixels);
          blackPixels ^= 1;
          if (codingLine[a0i] < columns) {
            ++b1i;
            while (refLine[b1i] <= codingLine[a0i] && refLine[b1i] < columns) {
              b1i += 2;
            }
          }
          break;
        case twoDimVertL3:
          addPixelsNeg(refLine[b1i] - 3, blackPixels);
          blackPixels ^= 1;
          if (codingLine[a0i] < columns) {
            if (b1i > 0) {
              --b1i;
            } else {
              ++b1i;
            }
            while (refLine[b1i] <= codingLine[a0i] && refLine[b1i] < columns) {
              b1i += 2;
            }
          }
          break;
        case twoDimVertL2:
          addPixelsNeg(refLine[b1i] - 2, blackPixels);
          blackPixels ^= 1;
          if (codingLine[a0i] < columns) {
            if (b1i > 0) {
              --b1i;
            } else {
              ++b1i;
            }
            while (refLine[b1i] <= codingLine[a0i] && refLine[b1i] < columns) {
              b1i += 2;
            }
          }
          break;
        case twoDimVertL1:
          addPixelsNeg(refLine[b1i] - 1, blackPixels);
          blackPixels ^= 1;
          if (codingLine[a0i] < columns) {
            if (b1i > 0) {
              --b1i;
            } else {
              ++b1i;
            }
            while (refLine[b1i] <= codingLine[a0i] && refLine[b1i] < columns) {
              b1i += 2;
            }
          }
          break;
        case EOF:
          addPixels(columns, 0);
          eof = gTrue;
          break;
        default:
          error(getPos(), "Bad 2D code %04x in CCITTFax stream", code1);
          addPixels(columns, 0);
          err = gTrue;
          break;
        }
      }

    // 1-D encoding
    } else {
      codingLine[0] = 0;
      a0i = 0;
      blackPixels = 0;
      while (codingLine[a0i] < columns) {
        code1 = 0;
        if (blackPixels) {
          do {
            code1 += code3 = getBlackCode();
          } while (code3 >= 64);
        } else {
          do {
            code1 += code3 = getWhiteCode();
          } while (code3 >= 64);
        }
        addPixels(codingLine[a0i] + code1, blackPixels);
        blackPixels ^= 1;
      }
    }

    // byte-align the row
    if (byteAlign) {
      inputBits &= ~7;
    }

    // check for end-of-line marker, skipping over any extra zero bits
    gotEOL = gFalse;
    if (!endOfBlock && row == rows - 1) {
      eof = gTrue;
    } else {
      code1 = lookBits(12);
      while (code1 == 0) {
        eatBits(1);
        code1 = lookBits(12);
      }
      if (code1 == 0x001) {
        eatBits(12);
        gotEOL = gTrue;
      } else if (code1 == EOF) {
        eof = gTrue;
      }
    }

    // get 2D encoding tag
    if (!eof && encoding > 0) {
      nextLine2D = !lookBits(1);
      eatBits(1);
    }

    // check for end-of-block marker
    if (endOfBlock && gotEOL) {
      code1 = lookBits(12);
      if (code1 == 0x001) {
        eatBits(12);
        if (encoding > 0) {
          lookBits(1);
          eatBits(1);
        }
        if (encoding >= 0) {
          for (i = 0; i < 4; ++i) {
            code1 = lookBits(12);
            if (code1 != 0x001) {
              error(getPos(), "Bad RTC code in CCITTFax stream");
            }
            eatBits(12);
            if (encoding > 0) {
              lookBits(1);
              eatBits(1);
            }
          }
        }
        eof = gTrue;
      }

    // look for an end-of-line marker after an error -- we only do
    // this if we know the stream contains end-of-line markers because
    // the "just plow on" technique tends to work better otherwise
    } else if (err && endOfLine) {
      while (1) {
        code1 = lookBits(13);
        if (code1 == EOF) {
          eof = gTrue;
          return EOF;
        }
        if ((code1 >> 1) == 0x001) {
          break;
        }
        eatBits(1);
      }
      eatBits(12); 
      if (encoding > 0) {
        eatBits(1);
        nextLine2D = !(code1 & 1);
      }
    }

    // set up for output
    if (codingLine[0] > 0) {
      outputBits = codingLine[a0i = 0];
    } else {
      outputBits = codingLine[a0i = 1];
    }

    ++row;
  }

  // get a byte
  if (outputBits >= 8) {
    buf = (a0i & 1) ? 0x00 : 0xff;
    outputBits -= 8;
    if (outputBits == 0 && codingLine[a0i] < columns) {
      ++a0i;
      outputBits = codingLine[a0i] - codingLine[a0i - 1];
    }
  } else {
    bits = 8;
    buf = 0;
    do {
      if (outputBits > bits) {
        buf <<= bits;
        if (!(a0i & 1)) {
          buf |= 0xff >> (8 - bits);
        }
        outputBits -= bits;
        bits = 0;
      } else {
        buf <<= outputBits;
        if (!(a0i & 1)) {
          buf |= 0xff >> (8 - outputBits);
        }
        bits -= outputBits;
        outputBits = 0;
        if (codingLine[a0i] < columns) {
          ++a0i;
          outputBits = codingLine[a0i] - codingLine[a0i - 1];
        } else if (bits > 0) {
          buf <<= bits;
          bits = 0;
        }
      }
    } while (bits);
  }
  if (black) {
    buf ^= 0xff;
  }
  return buf;
}

short CCITTFaxStream::getTwoDimCode() {
  short code;
  CCITTCode *p;
  int n;

  code = 0; // make gcc happy
  if (endOfBlock) {
    code = lookBits(7);
    p = &twoDimTab1[code];
    if (p->bits > 0) {
      eatBits(p->bits);
      return p->n;
    }
  } else {
    for (n = 1; n <= 7; ++n) {
      code = lookBits(n);
      if (n < 7) {
        code <<= 7 - n;
      }
      p = &twoDimTab1[code];
      if (p->bits == n) {
        eatBits(n);
        return p->n;
      }
    }
  }
  error(getPos(), "Bad two dim code (%04x) in CCITTFax stream", code);
  return EOF;
}

short CCITTFaxStream::getWhiteCode() {
  short code;
  CCITTCode *p;
  int n;

  code = 0; // make gcc happy
  if (endOfBlock) {
    code = lookBits(12);
    if (code == EOF) {
      return 1;
    }
    if ((code >> 5) == 0) {
      p = &whiteTab1[code];
    } else {
      p = &whiteTab2[code >> 3];
    }
    if (p->bits > 0) {
      eatBits(p->bits);
      return p->n;
    }
  } else {
    for (n = 1; n <= 9; ++n) {
      code = lookBits(n);
      if (code == EOF) {
        return 1;
      }
      if (n < 9) {
        code <<= 9 - n;
      }
      p = &whiteTab2[code];
      if (p->bits == n) {
        eatBits(n);
        return p->n;
      }
    }
    for (n = 11; n <= 12; ++n) {
      code = lookBits(n);
      if (code == EOF) {
        return 1;
      }
      if (n < 12) {
        code <<= 12 - n;
      }
      p = &whiteTab1[code];
      if (p->bits == n) {
        eatBits(n);
        return p->n;
      }
    }
  }
  error(getPos(), "Bad white code (%04x) in CCITTFax stream", code);
  // eat a bit and return a positive number so that the caller doesn't
  // go into an infinite loop
  eatBits(1);
  return 1;
}

short CCITTFaxStream::getBlackCode() {
  short code;
  CCITTCode *p;
  int n;

  code = 0; // make gcc happy
  if (endOfBlock) {
    code = lookBits(13);
    if (code == EOF) {
      return 1;
    }
    if ((code >> 7) == 0) {
      p = &blackTab1[code];
    } else if ((code >> 9) == 0 && (code >> 7) != 0) {
      p = &blackTab2[(code >> 1) - 64];
    } else {
      p = &blackTab3[code >> 7];
    }
    if (p->bits > 0) {
      eatBits(p->bits);
      return p->n;
    }
  } else {
    for (n = 2; n <= 6; ++n) {
      code = lookBits(n);
      if (code == EOF) {
        return 1;
      }
      if (n < 6) {
        code <<= 6 - n;
      }
      p = &blackTab3[code];
      if (p->bits == n) {
        eatBits(n);
        return p->n;
      }
    }
    for (n = 7; n <= 12; ++n) {
      code = lookBits(n);
      if (code == EOF) {
        return 1;
      }
      if (n < 12) {
        code <<= 12 - n;
      }
      if (code >= 64) {
        p = &blackTab2[code - 64];
        if (p->bits == n) {
          eatBits(n);
          return p->n;
        }
      }
    }
    for (n = 10; n <= 13; ++n) {
      code = lookBits(n);
      if (code == EOF) {
        return 1;
      }
      if (n < 13) {
        code <<= 13 - n;
      }
      p = &blackTab1[code];
      if (p->bits == n) {
        eatBits(n);
        return p->n;
      }
    }
  }
  error(getPos(), "Bad black code (%04x) in CCITTFax stream", code);
  // eat a bit and return a positive number so that the caller doesn't
  // go into an infinite loop
  eatBits(1);
  return 1;
}

short CCITTFaxStream::lookBits(int n) {
  int c;

  while (inputBits < n) {
    if ((c = str->getChar()) == EOF) {
      if (inputBits == 0) {
        return EOF;
      }
      // near the end of the stream, the caller may ask for more bits
      // than are available, but there may still be a valid code in
      // however many bits are available -- we need to return correct
      // data in this case
      return (inputBuf << (n - inputBits)) & (0xffff >> (16 - n));
    }
    inputBuf = (inputBuf << 8) + c;
    inputBits += 8;
  }
  return (inputBuf >> (inputBits - n)) & (0xffff >> (16 - n));
}

GString *CCITTFaxStream::getPSFilter(int psLevel, char *indent) {
  GString *s;
  char s1[50];

  if (psLevel < 2) {
    return NULL;
  }
  if (!(s = str->getPSFilter(psLevel, indent))) {
    return NULL;
  }
  s->append(indent)->append("<< ");
  if (encoding != 0) {
    sprintf(s1, "/K %d ", encoding);
    s->append(s1);
  }
  if (endOfLine) {
    s->append("/EndOfLine true ");
  }
  if (byteAlign) {
    s->append("/EncodedByteAlign true ");
  }
  sprintf(s1, "/Columns %d ", columns);
  s->append(s1);
  if (rows != 0) {
    sprintf(s1, "/Rows %d ", rows);
    s->append(s1);
  }
  if (!endOfBlock) {
    s->append("/EndOfBlock false ");
  }
  if (black) {
    s->append("/BlackIs1 true ");
  }
  s->append(">> /CCITTFaxDecode filter\n");
  return s;
}

GBool CCITTFaxStream::isBinary(GBool last) {
  return str->isBinary(gTrue);
}

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

// IDCT constants (20.12 fixed point format)
#define dctCos1    4017         // cos(pi/16)
#define dctSin1     799         // sin(pi/16)
#define dctCos3    3406         // cos(3*pi/16)
#define dctSin3    2276         // sin(3*pi/16)
#define dctCos6    1567         // cos(6*pi/16)
#define dctSin6    3784         // sin(6*pi/16)
#define dctSqrt2   5793         // sqrt(2)
#define dctSqrt1d2 2896         // sqrt(2) / 2

// color conversion parameters (16.16 fixed point format)
#define dctCrToR   91881        //  1.4020
#define dctCbToG  -22553        // -0.3441363
#define dctCrToG  -46802        // -0.71413636
#define dctCbToB  116130        //  1.772

// clip [-256,511] --> [0,255]
#define dctClipOffset 256
static Guchar dctClip[768];
static int dctClipInit = 0;

// zig zag decode map
static int dctZigZag[64] = {
   0,
   1,  8,
  16,  9,  2,
   3, 10, 17, 24,
  32, 25, 18, 11, 4,
   5, 12, 19, 26, 33, 40,
  48, 41, 34, 27, 20, 13,  6,
   7, 14, 21, 28, 35, 42, 49, 56,
  57, 50, 43, 36, 29, 22, 15,
  23, 30, 37, 44, 51, 58,
  59, 52, 45, 38, 31,
  39, 46, 53, 60,
  61, 54, 47,
  55, 62,
};

DCTStream::DCTStream(Stream *strA, GBool colorXformA):
    FilterStream(strA) {
  int i, j;

  colorXform = colorXformA;
  progressive = interleaved = gFalse;
  width = height = 0;
  mcuWidth = mcuHeight = 0;
  numComps = 0;
  comp = 0;
  x = y = dy = 0;
  for (i = 0; i < 4; ++i) {
    for (j = 0; j < 32; ++j) {
      rowBuf[i][j] = NULL;
    }
    frameBuf[i] = NULL;
  }

  if (!dctClipInit) {
    for (i = -256; i < 0; ++i)
      dctClip[dctClipOffset + i] = 0;
    for (i = 0; i < 256; ++i)
      dctClip[dctClipOffset + i] = i;
    for (i = 256; i < 512; ++i)
      dctClip[dctClipOffset + i] = 255;
    dctClipInit = 1;
  }
}

DCTStream::~DCTStream() {
  close();
  delete str;
}

void DCTStream::reset() {
  int i, j;

  str->reset();

  progressive = interleaved = gFalse;
  width = height = 0;
  numComps = 0;
  numQuantTables = 0;
  numDCHuffTables = 0;
  numACHuffTables = 0;
  gotJFIFMarker = gFalse;
  gotAdobeMarker = gFalse;
  restartInterval = 0;

  if (!readHeader()) {
    y = height;
    return;
  }

  // compute MCU size
  if (numComps == 1) {
    compInfo[0].hSample = compInfo[0].vSample = 1;
  }
  mcuWidth = compInfo[0].hSample;
  mcuHeight = compInfo[0].vSample;
  for (i = 1; i < numComps; ++i) {
    if (compInfo[i].hSample > mcuWidth) {
      mcuWidth = compInfo[i].hSample;
    }
    if (compInfo[i].vSample > mcuHeight) {
      mcuHeight = compInfo[i].vSample;
    }
  }
  mcuWidth *= 8;
  mcuHeight *= 8;

  // figure out color transform
  if (colorXform == -1) {
    if (numComps == 3) {
      if (gotJFIFMarker) {
        colorXform = 1;
      } else if (compInfo[0].id == 82 && compInfo[1].id == 71 &&
                 compInfo[2].id == 66) { // ASCII "RGB"
        colorXform = 0;
      } else {
        colorXform = 1;
      }
    } else {
      colorXform = 0;
    }
  }

  if (progressive || !interleaved) {

    // allocate a buffer for the whole image
    bufWidth = ((width + mcuWidth - 1) / mcuWidth) * mcuWidth;
    bufHeight = ((height + mcuHeight - 1) / mcuHeight) * mcuHeight;
    if (bufWidth <= 0 || bufHeight <= 0 ||
        bufWidth > INT_MAX / bufWidth / (int)sizeof(int)) {
      error(getPos(), "Invalid image size in DCT stream");
      y = height;
      return;
    }
    for (i = 0; i < numComps; ++i) {
      frameBuf[i] = (int *)gmallocn(bufWidth * bufHeight, sizeof(int));
      memset(frameBuf[i], 0, bufWidth * bufHeight * sizeof(int));
    }

    // read the image data
    do {
      restartMarker = 0xd0;
      restart();
      readScan();
    } while (readHeader());

    // decode
    decodeImage();

    // initialize counters
    comp = 0;
    x = 0;
    y = 0;

  } else {

    // allocate a buffer for one row of MCUs
    bufWidth = ((width + mcuWidth - 1) / mcuWidth) * mcuWidth;
    for (i = 0; i < numComps; ++i) {
      for (j = 0; j < mcuHeight; ++j) {
        rowBuf[i][j] = (Guchar *)gmallocn(bufWidth, sizeof(Guchar));
      }
    }

    // initialize counters
    comp = 0;
    x = 0;
    y = 0;
    dy = mcuHeight;

    restartMarker = 0xd0;
    restart();
  }
}

void DCTStream::close() {
  int i, j;

  for (i = 0; i < 4; ++i) {
    for (j = 0; j < 32; ++j) {
      gfree(rowBuf[i][j]);
      rowBuf[i][j] = NULL;
    }
    gfree(frameBuf[i]);
    frameBuf[i] = NULL;
  }
  FilterStream::close();
}

int DCTStream::getChar() {
  int c;

  if (y >= height) {
    return EOF;
  }
  if (progressive || !interleaved) {
    c = frameBuf[comp][y * bufWidth + x];
    if (++comp == numComps) {
      comp = 0;
      if (++x == width) {
        x = 0;
        ++y;
      }
    }
  } else {
    if (dy >= mcuHeight) {
      if (!readMCURow()) {
        y = height;
        return EOF;
      }
      comp = 0;
      x = 0;
      dy = 0;
    }
    c = rowBuf[comp][dy][x];
    if (++comp == numComps) {
      comp = 0;
      if (++x == width) {
        x = 0;
        ++y;
        ++dy;
        if (y == height) {
          readTrailer();
        }
      }
    }
  }
  return c;
}

int DCTStream::lookChar() {
  if (y >= height) {
    return EOF;
  }
  if (progressive || !interleaved) {
    return frameBuf[comp][y * bufWidth + x];
  } else {
    if (dy >= mcuHeight) {
      if (!readMCURow()) {
        y = height;
        return EOF;
      }
      comp = 0;
      x = 0;
      dy = 0;
    }
    return rowBuf[comp][dy][x];
  }
}

void DCTStream::restart() {
  int i;

  inputBits = 0;
  restartCtr = restartInterval;
  for (i = 0; i < numComps; ++i) {
    compInfo[i].prevDC = 0;
  }
  eobRun = 0;
}

// Read one row of MCUs from a sequential JPEG stream.
GBool DCTStream::readMCURow() {
  int data1[64];
  Guchar data2[64];
  Guchar *p1, *p2;
  int pY, pCb, pCr, pR, pG, pB;
  int h, v, horiz, vert, hSub, vSub;
  int x1, x2, y2, x3, y3, x4, y4, x5, y5, cc, i;
  int c;

  for (x1 = 0; x1 < width; x1 += mcuWidth) {

    // deal with restart marker
    if (restartInterval > 0 && restartCtr == 0) {
      c = readMarker();
      if (c != restartMarker) {
        error(getPos(), "Bad DCT data: incorrect restart marker");
        return gFalse;
      }
      if (++restartMarker == 0xd8)
        restartMarker = 0xd0;
      restart();
    }

    // read one MCU
    for (cc = 0; cc < numComps; ++cc) {
      h = compInfo[cc].hSample;
      v = compInfo[cc].vSample;
      horiz = mcuWidth / h;
      vert = mcuHeight / v;
      hSub = horiz / 8;
      vSub = vert / 8;
      for (y2 = 0; y2 < mcuHeight; y2 += vert) {
        for (x2 = 0; x2 < mcuWidth; x2 += horiz) {
          if (!readDataUnit(&dcHuffTables[scanInfo.dcHuffTable[cc]],
                            &acHuffTables[scanInfo.acHuffTable[cc]],
                            &compInfo[cc].prevDC,
                            data1)) {
            return gFalse;
          }
          transformDataUnit(quantTables[compInfo[cc].quantTable],
                            data1, data2);
          if (hSub == 1 && vSub == 1) {
            for (y3 = 0, i = 0; y3 < 8; ++y3, i += 8) {
              p1 = &rowBuf[cc][y2+y3][x1+x2];
              p1[0] = data2[i];
              p1[1] = data2[i+1];
              p1[2] = data2[i+2];
              p1[3] = data2[i+3];
              p1[4] = data2[i+4];
              p1[5] = data2[i+5];
              p1[6] = data2[i+6];
              p1[7] = data2[i+7];
            }
          } else if (hSub == 2 && vSub == 2) {
            for (y3 = 0, i = 0; y3 < 16; y3 += 2, i += 8) {
              p1 = &rowBuf[cc][y2+y3][x1+x2];
              p2 = &rowBuf[cc][y2+y3+1][x1+x2];
              p1[0] = p1[1] = p2[0] = p2[1] = data2[i];
              p1[2] = p1[3] = p2[2] = p2[3] = data2[i+1];
              p1[4] = p1[5] = p2[4] = p2[5] = data2[i+2];
              p1[6] = p1[7] = p2[6] = p2[7] = data2[i+3];
              p1[8] = p1[9] = p2[8] = p2[9] = data2[i+4];
              p1[10] = p1[11] = p2[10] = p2[11] = data2[i+5];
              p1[12] = p1[13] = p2[12] = p2[13] = data2[i+6];
              p1[14] = p1[15] = p2[14] = p2[15] = data2[i+7];
            }
          } else {
            i = 0;
            for (y3 = 0, y4 = 0; y3 < 8; ++y3, y4 += vSub) {
              for (x3 = 0, x4 = 0; x3 < 8; ++x3, x4 += hSub) {
                for (y5 = 0; y5 < vSub; ++y5)
                  for (x5 = 0; x5 < hSub; ++x5)
                    rowBuf[cc][y2+y4+y5][x1+x2+x4+x5] = data2[i];
                ++i;
              }
            }
          }
        }
      }
    }
    --restartCtr;

    // color space conversion
    if (colorXform) {
      // convert YCbCr to RGB
      if (numComps == 3) {
        for (y2 = 0; y2 < mcuHeight; ++y2) {
          for (x2 = 0; x2 < mcuWidth; ++x2) {
            pY = rowBuf[0][y2][x1+x2];
            pCb = rowBuf[1][y2][x1+x2] - 128;
            pCr = rowBuf[2][y2][x1+x2] - 128;
            pR = ((pY << 16) + dctCrToR * pCr + 32768) >> 16;
            rowBuf[0][y2][x1+x2] = dctClip[dctClipOffset + pR];
            pG = ((pY << 16) + dctCbToG * pCb + dctCrToG * pCr + 32768) >> 16;
            rowBuf[1][y2][x1+x2] = dctClip[dctClipOffset + pG];
            pB = ((pY << 16) + dctCbToB * pCb + 32768) >> 16;
            rowBuf[2][y2][x1+x2] = dctClip[dctClipOffset + pB];
          }
        }
      // convert YCbCrK to CMYK (K is passed through unchanged)
      } else if (numComps == 4) {
        for (y2 = 0; y2 < mcuHeight; ++y2) {
          for (x2 = 0; x2 < mcuWidth; ++x2) {
            pY = rowBuf[0][y2][x1+x2];
            pCb = rowBuf[1][y2][x1+x2] - 128;
            pCr = rowBuf[2][y2][x1+x2] - 128;
            pR = ((pY << 16) + dctCrToR * pCr + 32768) >> 16;
            rowBuf[0][y2][x1+x2] = 255 - dctClip[dctClipOffset + pR];
            pG = ((pY << 16) + dctCbToG * pCb + dctCrToG * pCr + 32768) >> 16;
            rowBuf[1][y2][x1+x2] = 255 - dctClip[dctClipOffset + pG];
            pB = ((pY << 16) + dctCbToB * pCb + 32768) >> 16;
            rowBuf[2][y2][x1+x2] = 255 - dctClip[dctClipOffset + pB];
          }
        }
      }
    }
  }
  return gTrue;
}

// Read one scan from a progressive or non-interleaved JPEG stream.
void DCTStream::readScan() {
  int data[64];
  int x1, y1, dx1, dy1, x2, y2, y3, cc, i;
  int h, v, horiz, vert, vSub;
  int *p1;
  int c;

  if (scanInfo.numComps == 1) {
    for (cc = 0; cc < numComps; ++cc) {
      if (scanInfo.comp[cc]) {
        break;
      }
    }
    dx1 = mcuWidth / compInfo[cc].hSample;
    dy1 = mcuHeight / compInfo[cc].vSample;
  } else {
    dx1 = mcuWidth;
    dy1 = mcuHeight;
  }

  for (y1 = 0; y1 < height; y1 += dy1) {
    for (x1 = 0; x1 < width; x1 += dx1) {

      // deal with restart marker
      if (restartInterval > 0 && restartCtr == 0) {
        c = readMarker();
        if (c != restartMarker) {
          error(getPos(), "Bad DCT data: incorrect restart marker");
          return;
        }
        if (++restartMarker == 0xd8) {
          restartMarker = 0xd0;
        }
        restart();
      }

      // read one MCU
      for (cc = 0; cc < numComps; ++cc) {
        if (!scanInfo.comp[cc]) {
          continue;
        }

        h = compInfo[cc].hSample;
        v = compInfo[cc].vSample;
        horiz = mcuWidth / h;
        vert = mcuHeight / v;
        vSub = vert / 8;
        for (y2 = 0; y2 < dy1; y2 += vert) {
          for (x2 = 0; x2 < dx1; x2 += horiz) {

            // pull out the current values
            p1 = &frameBuf[cc][(y1+y2) * bufWidth + (x1+x2)];
            for (y3 = 0, i = 0; y3 < 8; ++y3, i += 8) {
              data[i] = p1[0];
              data[i+1] = p1[1];
              data[i+2] = p1[2];
              data[i+3] = p1[3];
              data[i+4] = p1[4];
              data[i+5] = p1[5];
              data[i+6] = p1[6];
              data[i+7] = p1[7];
              p1 += bufWidth * vSub;
            }

            // read one data unit
            if (progressive) {
              if (!readProgressiveDataUnit(
                       &dcHuffTables[scanInfo.dcHuffTable[cc]],
                       &acHuffTables[scanInfo.acHuffTable[cc]],
                       &compInfo[cc].prevDC,
                       data)) {
                return;
              }
            } else {
              if (!readDataUnit(&dcHuffTables[scanInfo.dcHuffTable[cc]],
                                &acHuffTables[scanInfo.acHuffTable[cc]],
                                &compInfo[cc].prevDC,
                                data)) {
                return;
              }
            }

            // add the data unit into frameBuf
            p1 = &frameBuf[cc][(y1+y2) * bufWidth + (x1+x2)];
            for (y3 = 0, i = 0; y3 < 8; ++y3, i += 8) {
              p1[0] = data[i];
              p1[1] = data[i+1];
              p1[2] = data[i+2];
              p1[3] = data[i+3];
              p1[4] = data[i+4];
              p1[5] = data[i+5];
              p1[6] = data[i+6];
              p1[7] = data[i+7];
              p1 += bufWidth * vSub;
            }
          }
        }
      }
      --restartCtr;
    }
  }
}

// Read one data unit from a sequential JPEG stream.
GBool DCTStream::readDataUnit(DCTHuffTable *dcHuffTable,
                              DCTHuffTable *acHuffTable,
                              int *prevDC, int data[64]) {
  int run, size, amp;
  int c;
  int i, j;

  if ((size = readHuffSym(dcHuffTable)) == 9999) {
    return gFalse;
  }
  if (size > 0) {
    if ((amp = readAmp(size)) == 9999) {
      return gFalse;
    }
  } else {
    amp = 0;
  }
  data[0] = *prevDC += amp;
  for (i = 1; i < 64; ++i) {
    data[i] = 0;
  }
  i = 1;
  while (i < 64) {
    run = 0;
    while ((c = readHuffSym(acHuffTable)) == 0xf0 && run < 0x30) {
      run += 0x10;
    }
    if (c == 9999) {
      return gFalse;
    }
    if (c == 0x00) {
      break;
    } else {
      run += (c >> 4) & 0x0f;
      size = c & 0x0f;
      amp = readAmp(size);
      if (amp == 9999) {
        return gFalse;
      }
      i += run;
      if (i < 64) {
        j = dctZigZag[i++];
        data[j] = amp;
      }
    }
  }
  return gTrue;
}

// Read one data unit from a sequential JPEG stream.
GBool DCTStream::readProgressiveDataUnit(DCTHuffTable *dcHuffTable,
                                         DCTHuffTable *acHuffTable,
                                         int *prevDC, int data[64]) {
  int run, size, amp, bit, c;
  int i, j, k;

  // get the DC coefficient
  i = scanInfo.firstCoeff;
  if (i == 0) {
    if (scanInfo.ah == 0) {
      if ((size = readHuffSym(dcHuffTable)) == 9999) {
        return gFalse;
      }
      if (size > 0) {
        if ((amp = readAmp(size)) == 9999) {
          return gFalse;
        }
      } else {
        amp = 0;
      }
      data[0] += (*prevDC += amp) << scanInfo.al;
    } else {
      if ((bit = readBit()) == 9999) {
        return gFalse;
      }
      data[0] += bit << scanInfo.al;
    }
    ++i;
  }
  if (scanInfo.lastCoeff == 0) {
    return gTrue;
  }

  // check for an EOB run
  if (eobRun > 0) {
    while (i <= scanInfo.lastCoeff) {
      j = dctZigZag[i++];
      if (data[j] != 0) {
        if ((bit = readBit()) == EOF) {
          return gFalse;
        }
        if (bit) {
          data[j] += 1 << scanInfo.al;
        }
      }
    }
    --eobRun;
    return gTrue;
  }

  // read the AC coefficients
  while (i <= scanInfo.lastCoeff) {
    if ((c = readHuffSym(acHuffTable)) == 9999) {
      return gFalse;
    }

    // ZRL
    if (c == 0xf0) {
      k = 0;
      while (k < 16) {
        j = dctZigZag[i++];
        if (data[j] == 0) {
          ++k;
        } else {
          if ((bit = readBit()) == EOF) {
            return gFalse;
          }
          if (bit) {
            data[j] += 1 << scanInfo.al;
          }
        }
      }

    // EOB run
    } else if ((c & 0x0f) == 0x00) {
      j = c >> 4;
      eobRun = 0;
      for (k = 0; k < j; ++k) {
        if ((bit = readBit()) == EOF) {
          return gFalse;
        }
        eobRun = (eobRun << 1) | bit;
      }
      eobRun += 1 << j;
      while (i <= scanInfo.lastCoeff) {
        j = dctZigZag[i++];
        if (data[j] != 0) {
          if ((bit = readBit()) == EOF) {
            return gFalse;
          }
          if (bit) {
            data[j] += 1 << scanInfo.al;
          }
        }
      }
      --eobRun;
      break;

    // zero run and one AC coefficient
    } else {
      run = (c >> 4) & 0x0f;
      size = c & 0x0f;
      if ((amp = readAmp(size)) == 9999) {
        return gFalse;
      }
      k = 0;
      do {
        j = dctZigZag[i++];
        while (data[j] != 0) {
          if ((bit = readBit()) == EOF) {
            return gFalse;
          }
          if (bit) {
            data[j] += 1 << scanInfo.al;
          }
          j = dctZigZag[i++];
        }
        ++k;
      } while (k <= run);
      data[j] = amp << scanInfo.al;
    }
  }

  return gTrue;
}

// Decode a progressive JPEG image.
void DCTStream::decodeImage() {
  int dataIn[64];
  Guchar dataOut[64];
  Gushort *quantTable;
  int pY, pCb, pCr, pR, pG, pB;
  int x1, y1, x2, y2, x3, y3, x4, y4, x5, y5, cc, i;
  int h, v, horiz, vert, hSub, vSub;
  int *p0, *p1, *p2;

  for (y1 = 0; y1 < bufHeight; y1 += mcuHeight) {
    for (x1 = 0; x1 < bufWidth; x1 += mcuWidth) {
      for (cc = 0; cc < numComps; ++cc) {
        quantTable = quantTables[compInfo[cc].quantTable];
        h = compInfo[cc].hSample;
        v = compInfo[cc].vSample;
        horiz = mcuWidth / h;
        vert = mcuHeight / v;
        hSub = horiz / 8;
        vSub = vert / 8;
        for (y2 = 0; y2 < mcuHeight; y2 += vert) {
          for (x2 = 0; x2 < mcuWidth; x2 += horiz) {

            // pull out the coded data unit
            p1 = &frameBuf[cc][(y1+y2) * bufWidth + (x1+x2)];
            for (y3 = 0, i = 0; y3 < 8; ++y3, i += 8) {
              dataIn[i]   = p1[0];
              dataIn[i+1] = p1[1];
              dataIn[i+2] = p1[2];
              dataIn[i+3] = p1[3];
              dataIn[i+4] = p1[4];
              dataIn[i+5] = p1[5];
              dataIn[i+6] = p1[6];
              dataIn[i+7] = p1[7];
              p1 += bufWidth * vSub;
            }

            // transform
            transformDataUnit(quantTable, dataIn, dataOut);

            // store back into frameBuf, doing replication for
            // subsampled components
            p1 = &frameBuf[cc][(y1+y2) * bufWidth + (x1+x2)];
            if (hSub == 1 && vSub == 1) {
              for (y3 = 0, i = 0; y3 < 8; ++y3, i += 8) {
                p1[0] = dataOut[i] & 0xff;
                p1[1] = dataOut[i+1] & 0xff;
                p1[2] = dataOut[i+2] & 0xff;
                p1[3] = dataOut[i+3] & 0xff;
                p1[4] = dataOut[i+4] & 0xff;
                p1[5] = dataOut[i+5] & 0xff;
                p1[6] = dataOut[i+6] & 0xff;
                p1[7] = dataOut[i+7] & 0xff;
                p1 += bufWidth;
              }
            } else if (hSub == 2 && vSub == 2) {
              p2 = p1 + bufWidth;
              for (y3 = 0, i = 0; y3 < 16; y3 += 2, i += 8) {
                p1[0] = p1[1] = p2[0] = p2[1] = dataOut[i] & 0xff;
                p1[2] = p1[3] = p2[2] = p2[3] = dataOut[i+1] & 0xff;
                p1[4] = p1[5] = p2[4] = p2[5] = dataOut[i+2] & 0xff;
                p1[6] = p1[7] = p2[6] = p2[7] = dataOut[i+3] & 0xff;
                p1[8] = p1[9] = p2[8] = p2[9] = dataOut[i+4] & 0xff;
                p1[10] = p1[11] = p2[10] = p2[11] = dataOut[i+5] & 0xff;
                p1[12] = p1[13] = p2[12] = p2[13] = dataOut[i+6] & 0xff;
                p1[14] = p1[15] = p2[14] = p2[15] = dataOut[i+7] & 0xff;
                p1 += bufWidth * 2;
                p2 += bufWidth * 2;
              }
            } else {
              i = 0;
              for (y3 = 0, y4 = 0; y3 < 8; ++y3, y4 += vSub) {
                for (x3 = 0, x4 = 0; x3 < 8; ++x3, x4 += hSub) {
                  p2 = p1 + x4;
                  for (y5 = 0; y5 < vSub; ++y5) {
                    for (x5 = 0; x5 < hSub; ++x5) {
                      p2[x5] = dataOut[i] & 0xff;
                    }
                    p2 += bufWidth;
                  }
                  ++i;
                }
                p1 += bufWidth * vSub;
              }
            }
          }
        }
      }

      // color space conversion
      if (colorXform) {
        // convert YCbCr to RGB
        if (numComps == 3) {
          for (y2 = 0; y2 < mcuHeight; ++y2) {
            p0 = &frameBuf[0][(y1+y2) * bufWidth + x1];
            p1 = &frameBuf[1][(y1+y2) * bufWidth + x1];
            p2 = &frameBuf[2][(y1+y2) * bufWidth + x1];
            for (x2 = 0; x2 < mcuWidth; ++x2) {
              pY = *p0;
              pCb = *p1 - 128;
              pCr = *p2 - 128;
              pR = ((pY << 16) + dctCrToR * pCr + 32768) >> 16;
              *p0++ = dctClip[dctClipOffset + pR];
              pG = ((pY << 16) + dctCbToG * pCb + dctCrToG * pCr +
                    32768) >> 16;
              *p1++ = dctClip[dctClipOffset + pG];
              pB = ((pY << 16) + dctCbToB * pCb + 32768) >> 16;
              *p2++ = dctClip[dctClipOffset + pB];
            }
          }
        // convert YCbCrK to CMYK (K is passed through unchanged)
        } else if (numComps == 4) {
          for (y2 = 0; y2 < mcuHeight; ++y2) {
            p0 = &frameBuf[0][(y1+y2) * bufWidth + x1];
            p1 = &frameBuf[1][(y1+y2) * bufWidth + x1];
            p2 = &frameBuf[2][(y1+y2) * bufWidth + x1];
            for (x2 = 0; x2 < mcuWidth; ++x2) {
              pY = *p0;
              pCb = *p1 - 128;
              pCr = *p2 - 128;
              pR = ((pY << 16) + dctCrToR * pCr + 32768) >> 16;
              *p0++ = 255 - dctClip[dctClipOffset + pR];
              pG = ((pY << 16) + dctCbToG * pCb + dctCrToG * pCr +
                    32768) >> 16;
              *p1++ = 255 - dctClip[dctClipOffset + pG];
              pB = ((pY << 16) + dctCbToB * pCb + 32768) >> 16;
              *p2++ = 255 - dctClip[dctClipOffset + pB];
            }
          }
        }
      }
    }
  }
}

// Transform one data unit -- this performs the dequantization and
// IDCT steps.  This IDCT algorithm is taken from:
//   Christoph Loeffler, Adriaan Ligtenberg, George S. Moschytz,
//   "Practical Fast 1-D DCT Algorithms with 11 Multiplications",
//   IEEE Intl. Conf. on Acoustics, Speech & Signal Processing, 1989,
//   988-991.
// The stage numbers mentioned in the comments refer to Figure 1 in this
// paper.
void DCTStream::transformDataUnit(Gushort *quantTable,
                                  int dataIn[64], Guchar dataOut[64]) {
  int v0, v1, v2, v3, v4, v5, v6, v7, t;
  int *p;
  int i;

  // dequant
  for (i = 0; i < 64; ++i) {
    dataIn[i] *= quantTable[i];
  }

  // inverse DCT on rows
  for (i = 0; i < 64; i += 8) {
    p = dataIn + i;

    // check for all-zero AC coefficients
    if (p[1] == 0 && p[2] == 0 && p[3] == 0 &&
        p[4] == 0 && p[5] == 0 && p[6] == 0 && p[7] == 0) {
      t = (dctSqrt2 * p[0] + 512) >> 10;
      p[0] = t;
      p[1] = t;
      p[2] = t;
      p[3] = t;
      p[4] = t;
      p[5] = t;
      p[6] = t;
      p[7] = t;
      continue;
    }

    // stage 4
    v0 = (dctSqrt2 * p[0] + 128) >> 8;
    v1 = (dctSqrt2 * p[4] + 128) >> 8;
    v2 = p[2];
    v3 = p[6];
    v4 = (dctSqrt1d2 * (p[1] - p[7]) + 128) >> 8;
    v7 = (dctSqrt1d2 * (p[1] + p[7]) + 128) >> 8;
    v5 = p[3] << 4;
    v6 = p[5] << 4;

    // stage 3
    t = (v0 - v1+ 1) >> 1;
    v0 = (v0 + v1 + 1) >> 1;
    v1 = t;
    t = (v2 * dctSin6 + v3 * dctCos6 + 128) >> 8;
    v2 = (v2 * dctCos6 - v3 * dctSin6 + 128) >> 8;
    v3 = t;
    t = (v4 - v6 + 1) >> 1;
    v4 = (v4 + v6 + 1) >> 1;
    v6 = t;
    t = (v7 + v5 + 1) >> 1;
    v5 = (v7 - v5 + 1) >> 1;
    v7 = t;

    // stage 2
    t = (v0 - v3 + 1) >> 1;
    v0 = (v0 + v3 + 1) >> 1;
    v3 = t;
    t = (v1 - v2 + 1) >> 1;
    v1 = (v1 + v2 + 1) >> 1;
    v2 = t;
    t = (v4 * dctSin3 + v7 * dctCos3 + 2048) >> 12;
    v4 = (v4 * dctCos3 - v7 * dctSin3 + 2048) >> 12;
    v7 = t;
    t = (v5 * dctSin1 + v6 * dctCos1 + 2048) >> 12;
    v5 = (v5 * dctCos1 - v6 * dctSin1 + 2048) >> 12;
    v6 = t;

    // stage 1
    p[0] = v0 + v7;
    p[7] = v0 - v7;
    p[1] = v1 + v6;
    p[6] = v1 - v6;
    p[2] = v2 + v5;
    p[5] = v2 - v5;
    p[3] = v3 + v4;
    p[4] = v3 - v4;
  }

  // inverse DCT on columns
  for (i = 0; i < 8; ++i) {
    p = dataIn + i;

    // check for all-zero AC coefficients
    if (p[1*8] == 0 && p[2*8] == 0 && p[3*8] == 0 &&
        p[4*8] == 0 && p[5*8] == 0 && p[6*8] == 0 && p[7*8] == 0) {
      t = (dctSqrt2 * dataIn[i+0] + 8192) >> 14;
      p[0*8] = t;
      p[1*8] = t;
      p[2*8] = t;
      p[3*8] = t;
      p[4*8] = t;
      p[5*8] = t;
      p[6*8] = t;
      p[7*8] = t;
      continue;
    }

    // stage 4
    v0 = (dctSqrt2 * p[0*8] + 2048) >> 12;
    v1 = (dctSqrt2 * p[4*8] + 2048) >> 12;
    v2 = p[2*8];
    v3 = p[6*8];
    v4 = (dctSqrt1d2 * (p[1*8] - p[7*8]) + 2048) >> 12;
    v7 = (dctSqrt1d2 * (p[1*8] + p[7*8]) + 2048) >> 12;
    v5 = p[3*8];
    v6 = p[5*8];

    // stage 3
    t = (v0 - v1 + 1) >> 1;
    v0 = (v0 + v1 + 1) >> 1;
    v1 = t;
    t = (v2 * dctSin6 + v3 * dctCos6 + 2048) >> 12;
    v2 = (v2 * dctCos6 - v3 * dctSin6 + 2048) >> 12;
    v3 = t;
    t = (v4 - v6 + 1) >> 1;
    v4 = (v4 + v6 + 1) >> 1;
    v6 = t;
    t = (v7 + v5 + 1) >> 1;
    v5 = (v7 - v5 + 1) >> 1;
    v7 = t;

    // stage 2
    t = (v0 - v3 + 1) >> 1;
    v0 = (v0 + v3 + 1) >> 1;
    v3 = t;
    t = (v1 - v2 + 1) >> 1;
    v1 = (v1 + v2 + 1) >> 1;
    v2 = t;
    t = (v4 * dctSin3 + v7 * dctCos3 + 2048) >> 12;
    v4 = (v4 * dctCos3 - v7 * dctSin3 + 2048) >> 12;
    v7 = t;
    t = (v5 * dctSin1 + v6 * dctCos1 + 2048) >> 12;
    v5 = (v5 * dctCos1 - v6 * dctSin1 + 2048) >> 12;
    v6 = t;

    // stage 1
    p[0*8] = v0 + v7;
    p[7*8] = v0 - v7;
    p[1*8] = v1 + v6;
    p[6*8] = v1 - v6;
    p[2*8] = v2 + v5;
    p[5*8] = v2 - v5;
    p[3*8] = v3 + v4;
    p[4*8] = v3 - v4;
  }

  // convert to 8-bit integers
  for (i = 0; i < 64; ++i) {
    dataOut[i] = dctClip[dctClipOffset + 128 + ((dataIn[i] + 8) >> 4)];
  }
}

int DCTStream::readHuffSym(DCTHuffTable *table) {
  Gushort code;
  int bit;
  int codeBits;

  code = 0;
  codeBits = 0;
  do {
    // add a bit to the code
    if ((bit = readBit()) == EOF)
      return 9999;
    code = (code << 1) + bit;
    ++codeBits;

    // look up code
    if (code - table->firstCode[codeBits] < table->numCodes[codeBits]) {
      code -= table->firstCode[codeBits];
      return table->sym[table->firstSym[codeBits] + code];
    }
  } while (codeBits < 16);

  error(getPos(), "Bad Huffman code in DCT stream");
  return 9999;
}

int DCTStream::readAmp(int size) {
  int amp, bit;
  int bits;

  amp = 0;
  for (bits = 0; bits < size; ++bits) {
    if ((bit = readBit()) == EOF)
      return 9999;
    amp = (amp << 1) + bit;
  }
  if (amp < (1 << (size - 1)))
    amp -= (1 << size) - 1;
  return amp;
}

int DCTStream::readBit() {
  int bit;
  int c, c2;

  if (inputBits == 0) {
    if ((c = str->getChar()) == EOF)
      return EOF;
    if (c == 0xff) {
      do {
        c2 = str->getChar();
      } while (c2 == 0xff);
      if (c2 != 0x00) {
        error(getPos(), "Bad DCT data: missing 00 after ff");
        return EOF;
      }
    }
    inputBuf = c;
    inputBits = 8;
  }
  bit = (inputBuf >> (inputBits - 1)) & 1;
  --inputBits;
  return bit;
}

GBool DCTStream::readHeader() {
  GBool doScan;
  int n;
  int c = 0;
  int i;

  // read headers
  doScan = gFalse;
  while (!doScan) {
    c = readMarker();
    switch (c) {
    case 0xc0:                  // SOF0 (sequential)
    case 0xc1:                  // SOF1 (extended sequential)
      if (!readBaselineSOF()) {
        return gFalse;
      }
      break;
    case 0xc2:                  // SOF2 (progressive)
      if (!readProgressiveSOF()) {
        return gFalse;
      }
      break;
    case 0xc4:                  // DHT
      if (!readHuffmanTables()) {
        return gFalse;
      }
      break;
    case 0xd8:                  // SOI
      break;
    case 0xd9:                  // EOI
      return gFalse;
    case 0xda:                  // SOS
      if (!readScanInfo()) {
        return gFalse;
      }
      doScan = gTrue;
      break;
    case 0xdb:                  // DQT
      if (!readQuantTables()) {
        return gFalse;
      }
      break;
    case 0xdd:                  // DRI
      if (!readRestartInterval()) {
        return gFalse;
      }
      break;
    case 0xe0:                  // APP0
      if (!readJFIFMarker()) {
        return gFalse;
      }
      break;
    case 0xee:                  // APP14
      if (!readAdobeMarker()) {
        return gFalse;
      }
      break;
    case EOF:
      error(getPos(), "Bad DCT header");
      return gFalse;
    default:
      // skip APPn / COM / etc.
      if (c >= 0xe0) {
        n = read16() - 2;
        for (i = 0; i < n; ++i) {
          str->getChar();
        }
      } else {
        error(getPos(), "Unknown DCT marker <%02x>", c);
        return gFalse;
      }
      break;
    }
  }

  return gTrue;
}

GBool DCTStream::readBaselineSOF() {
  int length;
  int prec;
  int i;
  int c;

  length = read16();
  prec = str->getChar();
  height = read16();
  width = read16();
  numComps = str->getChar();
  if (numComps <= 0 || numComps > 4) {
    error(getPos(), "Bad number of components in DCT stream");
    numComps = 0;
    return gFalse;
  }
  if (prec != 8) {
    error(getPos(), "Bad DCT precision %d", prec);
    return gFalse;
  }
  for (i = 0; i < numComps; ++i) {
    compInfo[i].id = str->getChar();
    c = str->getChar();
    compInfo[i].hSample = (c >> 4) & 0x0f;
    compInfo[i].vSample = c & 0x0f;
    compInfo[i].quantTable = str->getChar();
  }
  progressive = gFalse;
  return gTrue;
}

GBool DCTStream::readProgressiveSOF() {
  int length;
  int prec;
  int i;
  int c;

  length = read16();
  prec = str->getChar();
  height = read16();
  width = read16();
  numComps = str->getChar();
  if (numComps <= 0 || numComps > 4) {
    error(getPos(), "Bad number of components in DCT stream");
    numComps = 0;
    return gFalse;
  }
  if (prec != 8) {
    error(getPos(), "Bad DCT precision %d", prec);
    return gFalse;
  }
  for (i = 0; i < numComps; ++i) {
    compInfo[i].id = str->getChar();
    c = str->getChar();
    compInfo[i].hSample = (c >> 4) & 0x0f;
    compInfo[i].vSample = c & 0x0f;
    compInfo[i].quantTable = str->getChar();
  }
  progressive = gTrue;
  return gTrue;
}

GBool DCTStream::readScanInfo() {
  int length;
  int id, c;
  int i, j;

  length = read16() - 2;
  scanInfo.numComps = str->getChar();
  if (scanInfo.numComps <= 0 || scanInfo.numComps > 4) {
    error(getPos(), "Bad number of components in DCT stream");
    scanInfo.numComps = 0;
    return gFalse;
  }
  --length;
  if (length != 2 * scanInfo.numComps + 3) {
    error(getPos(), "Bad DCT scan info block");
    return gFalse;
  }
  interleaved = scanInfo.numComps == numComps;
  for (j = 0; j < numComps; ++j) {
    scanInfo.comp[j] = gFalse;
  }
  for (i = 0; i < scanInfo.numComps; ++i) {
    id = str->getChar();
    // some (broken) DCT streams reuse ID numbers, but at least they
    // keep the components in order, so we check compInfo[i] first to
    // work around the problem
    if (id == compInfo[i].id) {
      j = i;
    } else {
      for (j = 0; j < numComps; ++j) {
        if (id == compInfo[j].id) {
          break;
        }
      }
      if (j == numComps) {
        error(getPos(), "Bad DCT component ID in scan info block");
        return gFalse;
      }
    }
    scanInfo.comp[j] = gTrue;
    c = str->getChar();
    scanInfo.dcHuffTable[j] = (c >> 4) & 0x0f;
    scanInfo.acHuffTable[j] = c & 0x0f;
  }
  scanInfo.firstCoeff = str->getChar();
  scanInfo.lastCoeff = str->getChar();
  if (scanInfo.firstCoeff < 0 || scanInfo.lastCoeff > 63 ||
      scanInfo.firstCoeff > scanInfo.lastCoeff) {
    error(getPos(), "Bad DCT coefficient numbers in scan info block");
    return gFalse;
  }
  c = str->getChar();
  scanInfo.ah = (c >> 4) & 0x0f;
  scanInfo.al = c & 0x0f;
  return gTrue;
}

GBool DCTStream::readQuantTables() {
  int length, prec, i, index;

  length = read16() - 2;
  while (length > 0) {
    index = str->getChar();
    prec = (index >> 4) & 0x0f;
    index &= 0x0f;
    if (prec > 1 || index >= 4) {
      error(getPos(), "Bad DCT quantization table");
      return gFalse;
    }
    if (index == numQuantTables) {
      numQuantTables = index + 1;
    }
    for (i = 0; i < 64; ++i) {
      if (prec) {
        quantTables[index][dctZigZag[i]] = read16();
      } else {
        quantTables[index][dctZigZag[i]] = str->getChar();
      }
    }
    if (prec) {
      length -= 129;
    } else {
      length -= 65;
    }
  }
  return gTrue;
}

GBool DCTStream::readHuffmanTables() {
  DCTHuffTable *tbl;
  int length;
  int index;
  Gushort code;
  Guchar sym;
  int i;
  int c;

  length = read16() - 2;
  while (length > 0) {
    index = str->getChar();
    --length;
    if ((index & 0x0f) >= 4) {
      error(getPos(), "Bad DCT Huffman table");
      return gFalse;
    }
    if (index & 0x10) {
      index &= 0x0f;
      if (index >= numACHuffTables)
        numACHuffTables = index+1;
      tbl = &acHuffTables[index];
    } else {
      index &= 0x0f;
      if (index >= numDCHuffTables)
        numDCHuffTables = index+1;
      tbl = &dcHuffTables[index];
    }
    sym = 0;
    code = 0;
    for (i = 1; i <= 16; ++i) {
      c = str->getChar();
      tbl->firstSym[i] = sym;
      tbl->firstCode[i] = code;
      tbl->numCodes[i] = c;
      sym += c;
      code = (code + c) << 1;
    }
    length -= 16;
    for (i = 0; i < sym; ++i)
      tbl->sym[i] = str->getChar();
    length -= sym;
  }
  return gTrue;
}

GBool DCTStream::readRestartInterval() {
  int length;

  length = read16();
  if (length != 4) {
    error(getPos(), "Bad DCT restart interval");
    return gFalse;
  }
  restartInterval = read16();
  return gTrue;
}

GBool DCTStream::readJFIFMarker() {
  int length, i;
  char buf[5];
  int c;

  length = read16();
  length -= 2;
  if (length >= 5) {
    for (i = 0; i < 5; ++i) {
      if ((c = str->getChar()) == EOF) {
        error(getPos(), "Bad DCT APP0 marker");
        return gFalse;
      }
      buf[i] = c;
    }
    length -= 5;
    if (!memcmp(buf, "JFIF\0", 5)) {
      gotJFIFMarker = gTrue;
    }
  }
  while (length > 0) {
    if (str->getChar() == EOF) {
      error(getPos(), "Bad DCT APP0 marker");
      return gFalse;
    }
    --length;
  }
  return gTrue;
}

GBool DCTStream::readAdobeMarker() {
  int length, i;
  char buf[12];
  int c;

  length = read16();
  if (length < 14) {
    goto err;
  }
  for (i = 0; i < 12; ++i) {
    if ((c = str->getChar()) == EOF) {
      goto err;
    }
    buf[i] = c;
  }
  if (strncmp(buf, "Adobe", 5)) {
    goto err;
  }
  colorXform = buf[11];
  gotAdobeMarker = gTrue;
  for (i = 14; i < length; ++i) {
    if (str->getChar() == EOF) {
      goto err;
    }
  }
  return gTrue;

 err:
  error(getPos(), "Bad DCT Adobe APP14 marker");
  return gFalse;
}

GBool DCTStream::readTrailer() {
  int c;

  c = readMarker();
  if (c != 0xd9) {              // EOI
    error(getPos(), "Bad DCT trailer");
    return gFalse;
  }
  return gTrue;
}

int DCTStream::readMarker() {
  int c;

  do {
    do {
      c = str->getChar();
    } while (c != 0xff && c != EOF);
    do {
      c = str->getChar();
    } while (c == 0xff);
  } while (c == 0x00);
  return c;
}

int DCTStream::read16() {
  int c1, c2;

  if ((c1 = str->getChar()) == EOF)
    return EOF;
  if ((c2 = str->getChar()) == EOF)
    return EOF;
  return (c1 << 8) + c2;
}

GString *DCTStream::getPSFilter(int psLevel, char *indent) {
  GString *s;

  if (psLevel < 2) {
    return NULL;
  }
  if (!(s = str->getPSFilter(psLevel, indent))) {
    return NULL;
  }
  s->append(indent)->append("<< >> /DCTDecode filter\n");
  return s;
}

GBool DCTStream::isBinary(GBool last) {
  return str->isBinary(gTrue);
}

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

int FlateStream::codeLenCodeMap[flateMaxCodeLenCodes] = {
  16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15
};

FlateDecode FlateStream::lengthDecode[flateMaxLitCodes-257] = {
  {0,   3},
  {0,   4},
  {0,   5},
  {0,   6},
  {0,   7},
  {0,   8},
  {0,   9},
  {0,  10},
  {1,  11},
  {1,  13},
  {1,  15},
  {1,  17},
  {2,  19},
  {2,  23},
  {2,  27},
  {2,  31},
  {3,  35},
  {3,  43},
  {3,  51},
  {3,  59},
  {4,  67},
  {4,  83},
  {4,  99},
  {4, 115},
  {5, 131},
  {5, 163},
  {5, 195},
  {5, 227},
  {0, 258},
  {0, 258},
  {0, 258}
};

FlateDecode FlateStream::distDecode[flateMaxDistCodes] = {
  { 0,     1},
  { 0,     2},
  { 0,     3},
  { 0,     4},
  { 1,     5},
  { 1,     7},
  { 2,     9},
  { 2,    13},
  { 3,    17},
  { 3,    25},
  { 4,    33},
  { 4,    49},
  { 5,    65},
  { 5,    97},
  { 6,   129},
  { 6,   193},
  { 7,   257},
  { 7,   385},
  { 8,   513},
  { 8,   769},
  { 9,  1025},
  { 9,  1537},
  {10,  2049},
  {10,  3073},
  {11,  4097},
  {11,  6145},
  {12,  8193},
  {12, 12289},
  {13, 16385},
  {13, 24577}
};

static FlateCode flateFixedLitCodeTabCodes[512] = {
  {7, 0x0100},
  {8, 0x0050},
  {8, 0x0010},
  {8, 0x0118},
  {7, 0x0110},
  {8, 0x0070},
  {8, 0x0030},
  {9, 0x00c0},
  {7, 0x0108},
  {8, 0x0060},
  {8, 0x0020},
  {9, 0x00a0},
  {8, 0x0000},
  {8, 0x0080},
  {8, 0x0040},
  {9, 0x00e0},
  {7, 0x0104},
  {8, 0x0058},
  {8, 0x0018},
  {9, 0x0090},
  {7, 0x0114},
  {8, 0x0078},
  {8, 0x0038},
  {9, 0x00d0},
  {7, 0x010c},
  {8, 0x0068},
  {8, 0x0028},
  {9, 0x00b0},
  {8, 0x0008},
  {8, 0x0088},
  {8, 0x0048},
  {9, 0x00f0},
  {7, 0x0102},
  {8, 0x0054},
  {8, 0x0014},
  {8, 0x011c},
  {7, 0x0112},
  {8, 0x0074},
  {8, 0x0034},
  {9, 0x00c8},
  {7, 0x010a},
  {8, 0x0064},
  {8, 0x0024},
  {9, 0x00a8},
  {8, 0x0004},
  {8, 0x0084},
  {8, 0x0044},
  {9, 0x00e8},
  {7, 0x0106},
  {8, 0x005c},
  {8, 0x001c},
  {9, 0x0098},
  {7, 0x0116},
  {8, 0x007c},
  {8, 0x003c},
  {9, 0x00d8},
  {7, 0x010e},
  {8, 0x006c},
  {8, 0x002c},
  {9, 0x00b8},
  {8, 0x000c},
  {8, 0x008c},
  {8, 0x004c},
  {9, 0x00f8},
  {7, 0x0101},
  {8, 0x0052},
  {8, 0x0012},
  {8, 0x011a},
  {7, 0x0111},
  {8, 0x0072},
  {8, 0x0032},
  {9, 0x00c4},
  {7, 0x0109},
  {8, 0x0062},
  {8, 0x0022},
  {9, 0x00a4},
  {8, 0x0002},
  {8, 0x0082},
  {8, 0x0042},
  {9, 0x00e4},
  {7, 0x0105},
  {8, 0x005a},
  {8, 0x001a},
  {9, 0x0094},
  {7, 0x0115},
  {8, 0x007a},
  {8, 0x003a},
  {9, 0x00d4},
  {7, 0x010d},
  {8, 0x006a},
  {8, 0x002a},
  {9, 0x00b4},
  {8, 0x000a},
  {8, 0x008a},
  {8, 0x004a},
  {9, 0x00f4},
  {7, 0x0103},
  {8, 0x0056},
  {8, 0x0016},
  {8, 0x011e},
  {7, 0x0113},
  {8, 0x0076},
  {8, 0x0036},
  {9, 0x00cc},
  {7, 0x010b},
  {8, 0x0066},
  {8, 0x0026},
  {9, 0x00ac},
  {8, 0x0006},
  {8, 0x0086},
  {8, 0x0046},
  {9, 0x00ec},
  {7, 0x0107},
  {8, 0x005e},
  {8, 0x001e},
  {9, 0x009c},
  {7, 0x0117},
  {8, 0x007e},
  {8, 0x003e},
  {9, 0x00dc},
  {7, 0x010f},
  {8, 0x006e},
  {8, 0x002e},
  {9, 0x00bc},
  {8, 0x000e},
  {8, 0x008e},
  {8, 0x004e},
  {9, 0x00fc},
  {7, 0x0100},
  {8, 0x0051},
  {8, 0x0011},
  {8, 0x0119},
  {7, 0x0110},
  {8, 0x0071},
  {8, 0x0031},
  {9, 0x00c2},
  {7, 0x0108},
  {8, 0x0061},
  {8, 0x0021},
  {9, 0x00a2},
  {8, 0x0001},
  {8, 0x0081},
  {8, 0x0041},
  {9, 0x00e2},
  {7, 0x0104},
  {8, 0x0059},
  {8, 0x0019},
  {9, 0x0092},
  {7, 0x0114},
  {8, 0x0079},
  {8, 0x0039},
  {9, 0x00d2},
  {7, 0x010c},
  {8, 0x0069},
  {8, 0x0029},
  {9, 0x00b2},
  {8, 0x0009},
  {8, 0x0089},
  {8, 0x0049},
  {9, 0x00f2},
  {7, 0x0102},
  {8, 0x0055},
  {8, 0x0015},
  {8, 0x011d},
  {7, 0x0112},
  {8, 0x0075},
  {8, 0x0035},
  {9, 0x00ca},
  {7, 0x010a},
  {8, 0x0065},
  {8, 0x0025},
  {9, 0x00aa},
  {8, 0x0005},
  {8, 0x0085},
  {8, 0x0045},
  {9, 0x00ea},
  {7, 0x0106},
  {8, 0x005d},
  {8, 0x001d},
  {9, 0x009a},
  {7, 0x0116},
  {8, 0x007d},
  {8, 0x003d},
  {9, 0x00da},
  {7, 0x010e},
  {8, 0x006d},
  {8, 0x002d},
  {9, 0x00ba},
  {8, 0x000d},
  {8, 0x008d},
  {8, 0x004d},
  {9, 0x00fa},
  {7, 0x0101},
  {8, 0x0053},
  {8, 0x0013},
  {8, 0x011b},
  {7, 0x0111},
  {8, 0x0073},
  {8, 0x0033},
  {9, 0x00c6},
  {7, 0x0109},
  {8, 0x0063},
  {8, 0x0023},
  {9, 0x00a6},
  {8, 0x0003},
  {8, 0x0083},
  {8, 0x0043},
  {9, 0x00e6},
  {7, 0x0105},
  {8, 0x005b},
  {8, 0x001b},
  {9, 0x0096},
  {7, 0x0115},
  {8, 0x007b},
  {8, 0x003b},
  {9, 0x00d6},
  {7, 0x010d},
  {8, 0x006b},
  {8, 0x002b},
  {9, 0x00b6},
  {8, 0x000b},
  {8, 0x008b},
  {8, 0x004b},
  {9, 0x00f6},
  {7, 0x0103},
  {8, 0x0057},
  {8, 0x0017},
  {8, 0x011f},
  {7, 0x0113},
  {8, 0x0077},
  {8, 0x0037},
  {9, 0x00ce},
  {7, 0x010b},
  {8, 0x0067},
  {8, 0x0027},
  {9, 0x00ae},
  {8, 0x0007},
  {8, 0x0087},
  {8, 0x0047},
  {9, 0x00ee},
  {7, 0x0107},
  {8, 0x005f},
  {8, 0x001f},
  {9, 0x009e},
  {7, 0x0117},
  {8, 0x007f},
  {8, 0x003f},
  {9, 0x00de},
  {7, 0x010f},
  {8, 0x006f},
  {8, 0x002f},
  {9, 0x00be},
  {8, 0x000f},
  {8, 0x008f},
  {8, 0x004f},
  {9, 0x00fe},
  {7, 0x0100},
  {8, 0x0050},
  {8, 0x0010},
  {8, 0x0118},
  {7, 0x0110},
  {8, 0x0070},
  {8, 0x0030},
  {9, 0x00c1},
  {7, 0x0108},
  {8, 0x0060},
  {8, 0x0020},
  {9, 0x00a1},
  {8, 0x0000},
  {8, 0x0080},
  {8, 0x0040},
  {9, 0x00e1},
  {7, 0x0104},
  {8, 0x0058},
  {8, 0x0018},
  {9, 0x0091},
  {7, 0x0114},
  {8, 0x0078},
  {8, 0x0038},
  {9, 0x00d1},
  {7, 0x010c},
  {8, 0x0068},
  {8, 0x0028},
  {9, 0x00b1},
  {8, 0x0008},
  {8, 0x0088},
  {8, 0x0048},
  {9, 0x00f1},
  {7, 0x0102},
  {8, 0x0054},
  {8, 0x0014},
  {8, 0x011c},
  {7, 0x0112},
  {8, 0x0074},
  {8, 0x0034},
  {9, 0x00c9},
  {7, 0x010a},
  {8, 0x0064},
  {8, 0x0024},
  {9, 0x00a9},
  {8, 0x0004},
  {8, 0x0084},
  {8, 0x0044},
  {9, 0x00e9},
  {7, 0x0106},
  {8, 0x005c},
  {8, 0x001c},
  {9, 0x0099},
  {7, 0x0116},
  {8, 0x007c},
  {8, 0x003c},
  {9, 0x00d9},
  {7, 0x010e},
  {8, 0x006c},
  {8, 0x002c},
  {9, 0x00b9},
  {8, 0x000c},
  {8, 0x008c},
  {8, 0x004c},
  {9, 0x00f9},
  {7, 0x0101},
  {8, 0x0052},
  {8, 0x0012},
  {8, 0x011a},
  {7, 0x0111},
  {8, 0x0072},
  {8, 0x0032},
  {9, 0x00c5},
  {7, 0x0109},
  {8, 0x0062},
  {8, 0x0022},
  {9, 0x00a5},
  {8, 0x0002},
  {8, 0x0082},
  {8, 0x0042},
  {9, 0x00e5},
  {7, 0x0105},
  {8, 0x005a},
  {8, 0x001a},
  {9, 0x0095},
  {7, 0x0115},
  {8, 0x007a},
  {8, 0x003a},
  {9, 0x00d5},
  {7, 0x010d},
  {8, 0x006a},
  {8, 0x002a},
  {9, 0x00b5},
  {8, 0x000a},
  {8, 0x008a},
  {8, 0x004a},
  {9, 0x00f5},
  {7, 0x0103},
  {8, 0x0056},
  {8, 0x0016},
  {8, 0x011e},
  {7, 0x0113},
  {8, 0x0076},
  {8, 0x0036},
  {9, 0x00cd},
  {7, 0x010b},
  {8, 0x0066},
  {8, 0x0026},
  {9, 0x00ad},
  {8, 0x0006},
  {8, 0x0086},
  {8, 0x0046},
  {9, 0x00ed},
  {7, 0x0107},
  {8, 0x005e},
  {8, 0x001e},
  {9, 0x009d},
  {7, 0x0117},
  {8, 0x007e},
  {8, 0x003e},
  {9, 0x00dd},
  {7, 0x010f},
  {8, 0x006e},
  {8, 0x002e},
  {9, 0x00bd},
  {8, 0x000e},
  {8, 0x008e},
  {8, 0x004e},
  {9, 0x00fd},
  {7, 0x0100},
  {8, 0x0051},
  {8, 0x0011},
  {8, 0x0119},
  {7, 0x0110},
  {8, 0x0071},
  {8, 0x0031},
  {9, 0x00c3},
  {7, 0x0108},
  {8, 0x0061},
  {8, 0x0021},
  {9, 0x00a3},
  {8, 0x0001},
  {8, 0x0081},
  {8, 0x0041},
  {9, 0x00e3},
  {7, 0x0104},
  {8, 0x0059},
  {8, 0x0019},
  {9, 0x0093},
  {7, 0x0114},
  {8, 0x0079},
  {8, 0x0039},
  {9, 0x00d3},
  {7, 0x010c},
  {8, 0x0069},
  {8, 0x0029},
  {9, 0x00b3},
  {8, 0x0009},
  {8, 0x0089},
  {8, 0x0049},
  {9, 0x00f3},
  {7, 0x0102},
  {8, 0x0055},
  {8, 0x0015},
  {8, 0x011d},
  {7, 0x0112},
  {8, 0x0075},
  {8, 0x0035},
  {9, 0x00cb},
  {7, 0x010a},
  {8, 0x0065},
  {8, 0x0025},
  {9, 0x00ab},
  {8, 0x0005},
  {8, 0x0085},
  {8, 0x0045},
  {9, 0x00eb},
  {7, 0x0106},
  {8, 0x005d},
  {8, 0x001d},
  {9, 0x009b},
  {7, 0x0116},
  {8, 0x007d},
  {8, 0x003d},
  {9, 0x00db},
  {7, 0x010e},
  {8, 0x006d},
  {8, 0x002d},
  {9, 0x00bb},
  {8, 0x000d},
  {8, 0x008d},
  {8, 0x004d},
  {9, 0x00fb},
  {7, 0x0101},
  {8, 0x0053},
  {8, 0x0013},
  {8, 0x011b},
  {7, 0x0111},
  {8, 0x0073},
  {8, 0x0033},
  {9, 0x00c7},
  {7, 0x0109},
  {8, 0x0063},
  {8, 0x0023},
  {9, 0x00a7},
  {8, 0x0003},
  {8, 0x0083},
  {8, 0x0043},
  {9, 0x00e7},
  {7, 0x0105},
  {8, 0x005b},
  {8, 0x001b},
  {9, 0x0097},
  {7, 0x0115},
  {8, 0x007b},
  {8, 0x003b},
  {9, 0x00d7},
  {7, 0x010d},
  {8, 0x006b},
  {8, 0x002b},
  {9, 0x00b7},
  {8, 0x000b},
  {8, 0x008b},
  {8, 0x004b},
  {9, 0x00f7},
  {7, 0x0103},
  {8, 0x0057},
  {8, 0x0017},
  {8, 0x011f},
  {7, 0x0113},
  {8, 0x0077},
  {8, 0x0037},
  {9, 0x00cf},
  {7, 0x010b},
  {8, 0x0067},
  {8, 0x0027},
  {9, 0x00af},
  {8, 0x0007},
  {8, 0x0087},
  {8, 0x0047},
  {9, 0x00ef},
  {7, 0x0107},
  {8, 0x005f},
  {8, 0x001f},
  {9, 0x009f},
  {7, 0x0117},
  {8, 0x007f},
  {8, 0x003f},
  {9, 0x00df},
  {7, 0x010f},
  {8, 0x006f},
  {8, 0x002f},
  {9, 0x00bf},
  {8, 0x000f},
  {8, 0x008f},
  {8, 0x004f},
  {9, 0x00ff}
};

FlateHuffmanTab FlateStream::fixedLitCodeTab = {
  flateFixedLitCodeTabCodes, 9
};

static FlateCode flateFixedDistCodeTabCodes[32] = {
  {5, 0x0000},
  {5, 0x0010},
  {5, 0x0008},
  {5, 0x0018},
  {5, 0x0004},
  {5, 0x0014},
  {5, 0x000c},
  {5, 0x001c},
  {5, 0x0002},
  {5, 0x0012},
  {5, 0x000a},
  {5, 0x001a},
  {5, 0x0006},
  {5, 0x0016},
  {5, 0x000e},
  {0, 0x0000},
  {5, 0x0001},
  {5, 0x0011},
  {5, 0x0009},
  {5, 0x0019},
  {5, 0x0005},
  {5, 0x0015},
  {5, 0x000d},
  {5, 0x001d},
  {5, 0x0003},
  {5, 0x0013},
  {5, 0x000b},
  {5, 0x001b},
  {5, 0x0007},
  {5, 0x0017},
  {5, 0x000f},
  {0, 0x0000}
};

FlateHuffmanTab FlateStream::fixedDistCodeTab = {
  flateFixedDistCodeTabCodes, 5
};

FlateStream::FlateStream(Stream *strA, int predictor, int columns,
                         int colors, int bits):
    FilterStream(strA) {
  if (predictor != 1) {
    pred = new StreamPredictor(this, predictor, columns, colors, bits);
    if (!pred->isOk()) {
      delete pred;
      pred = NULL;
    }
  } else {
    pred = NULL;
  }
  litCodeTab.codes = NULL;
  distCodeTab.codes = NULL;
  memset(buf, 0, flateWindow);
}

FlateStream::~FlateStream() {
  if (litCodeTab.codes != fixedLitCodeTab.codes) {
    gfree(litCodeTab.codes);
  }
  if (distCodeTab.codes != fixedDistCodeTab.codes) {
    gfree(distCodeTab.codes);
  }
  if (pred) {
    delete pred;
  }
  delete str;
}

void FlateStream::reset() {
  int cmf, flg;

  index = 0;
  remain = 0;
  codeBuf = 0;
  codeSize = 0;
  compressedBlock = gFalse;
  endOfBlock = gTrue;
  eof = gTrue;

  str->reset();

  // read header
  //~ need to look at window size?
  endOfBlock = eof = gTrue;
  cmf = str->getChar();
  flg = str->getChar();
  if (cmf == EOF || flg == EOF)
    return;
  if ((cmf & 0x0f) != 0x08) {
    error(getPos(), "Unknown compression method in flate stream");
    return;
  }
  if ((((cmf << 8) + flg) % 31) != 0) {
    error(getPos(), "Bad FCHECK in flate stream");
    return;
  }
  if (flg & 0x20) {
    error(getPos(), "FDICT bit set in flate stream");
    return;
  }

  eof = gFalse;
}

int FlateStream::getChar() {
  int c;

  if (pred) {
    return pred->getChar();
  }
  while (remain == 0) {
    if (endOfBlock && eof)
      return EOF;
    readSome();
  }
  c = buf[index];
  index = (index + 1) & flateMask;
  --remain;
  return c;
}

int FlateStream::lookChar() {
  int c;

  if (pred) {
    return pred->lookChar();
  }
  while (remain == 0) {
    if (endOfBlock && eof)
      return EOF;
    readSome();
  }
  c = buf[index];
  return c;
}

int FlateStream::getRawChar() {
  int c;

  while (remain == 0) {
    if (endOfBlock && eof)
      return EOF;
    readSome();
  }
  c = buf[index];
  index = (index + 1) & flateMask;
  --remain;
  return c;
}

GString *FlateStream::getPSFilter(int psLevel, char *indent) {
  GString *s;

  if (psLevel < 3 || pred) {
    return NULL;
  }
  if (!(s = str->getPSFilter(psLevel, indent))) {
    return NULL;
  }
  s->append(indent)->append("<< >> /FlateDecode filter\n");
  return s;
}

GBool FlateStream::isBinary(GBool last) {
  return str->isBinary(gTrue);
}

void FlateStream::readSome() {
  int code1, code2;
  int len, dist;
  int i, j, k;
  int c;

  if (endOfBlock) {
    if (!startBlock())
      return;
  }

  if (compressedBlock) {
    if ((code1 = getHuffmanCodeWord(&litCodeTab)) == EOF)
      goto err;
    if (code1 < 256) {
      buf[index] = code1;
      remain = 1;
    } else if (code1 == 256) {
      endOfBlock = gTrue;
      remain = 0;
    } else {
      code1 -= 257;
      code2 = lengthDecode[code1].bits;
      if (code2 > 0 && (code2 = getCodeWord(code2)) == EOF)
        goto err;
      len = lengthDecode[code1].first + code2;
      if ((code1 = getHuffmanCodeWord(&distCodeTab)) == EOF)
        goto err;
      code2 = distDecode[code1].bits;
      if (code2 > 0 && (code2 = getCodeWord(code2)) == EOF)
        goto err;
      dist = distDecode[code1].first + code2;
      i = index;
      j = (index - dist) & flateMask;
      for (k = 0; k < len; ++k) {
        buf[i] = buf[j];
        i = (i + 1) & flateMask;
        j = (j + 1) & flateMask;
      }
      remain = len;
    }

  } else {
    len = (blockLen < flateWindow) ? blockLen : flateWindow;
    for (i = 0, j = index; i < len; ++i, j = (j + 1) & flateMask) {
      if ((c = str->getChar()) == EOF) {
        endOfBlock = eof = gTrue;
        break;
      }
      buf[j] = c & 0xff;
    }
    remain = i;
    blockLen -= len;
    if (blockLen == 0)
      endOfBlock = gTrue;
  }

  return;

err:
  error(getPos(), "Unexpected end of file in flate stream");
  endOfBlock = eof = gTrue;
  remain = 0;
}

GBool FlateStream::startBlock() {
  int blockHdr;
  int c;
  int check;

  // free the code tables from the previous block
  if (litCodeTab.codes != fixedLitCodeTab.codes) {
    gfree(litCodeTab.codes);
  }
  litCodeTab.codes = NULL;
  if (distCodeTab.codes != fixedDistCodeTab.codes) {
    gfree(distCodeTab.codes);
  }
  distCodeTab.codes = NULL;

  // read block header
  blockHdr = getCodeWord(3);
  if (blockHdr & 1)
    eof = gTrue;
  blockHdr >>= 1;

  // uncompressed block
  if (blockHdr == 0) {
    compressedBlock = gFalse;
    if ((c = str->getChar()) == EOF)
      goto err;
    blockLen = c & 0xff;
    if ((c = str->getChar()) == EOF)
      goto err;
    blockLen |= (c & 0xff) << 8;
    if ((c = str->getChar()) == EOF)
      goto err;
    check = c & 0xff;
    if ((c = str->getChar()) == EOF)
      goto err;
    check |= (c & 0xff) << 8;
    if (check != (~blockLen & 0xffff))
      error(getPos(), "Bad uncompressed block length in flate stream");
    codeBuf = 0;
    codeSize = 0;

  // compressed block with fixed codes
  } else if (blockHdr == 1) {
    compressedBlock = gTrue;
    loadFixedCodes();

  // compressed block with dynamic codes
  } else if (blockHdr == 2) {
    compressedBlock = gTrue;
    if (!readDynamicCodes()) {
      goto err;
    }

  // unknown block type
  } else {
    goto err;
  }

  endOfBlock = gFalse;
  return gTrue;

err:
  error(getPos(), "Bad block header in flate stream");
  endOfBlock = eof = gTrue;
  return gFalse;
}

void FlateStream::loadFixedCodes() {
  litCodeTab.codes = fixedLitCodeTab.codes;
  litCodeTab.maxLen = fixedLitCodeTab.maxLen;
  distCodeTab.codes = fixedDistCodeTab.codes;
  distCodeTab.maxLen = fixedDistCodeTab.maxLen;
}

GBool FlateStream::readDynamicCodes() {
  int numCodeLenCodes;
  int numLitCodes;
  int numDistCodes;
  int codeLenCodeLengths[flateMaxCodeLenCodes];
  FlateHuffmanTab codeLenCodeTab;
  int len, repeat, code;
  int i;

  codeLenCodeTab.codes = NULL;

  // read lengths
  if ((numLitCodes = getCodeWord(5)) == EOF) {
    goto err;
  }
  numLitCodes += 257;
  if ((numDistCodes = getCodeWord(5)) == EOF) {
    goto err;
  }
  numDistCodes += 1;
  if ((numCodeLenCodes = getCodeWord(4)) == EOF) {
    goto err;
  }
  numCodeLenCodes += 4;
  if (numLitCodes > flateMaxLitCodes ||
      numDistCodes > flateMaxDistCodes ||
      numCodeLenCodes > flateMaxCodeLenCodes) {
    goto err;
  }

  // build the code length code table
  for (i = 0; i < flateMaxCodeLenCodes; ++i) {
    codeLenCodeLengths[i] = 0;
  }
  for (i = 0; i < numCodeLenCodes; ++i) {
    if ((codeLenCodeLengths[codeLenCodeMap[i]] = getCodeWord(3)) == -1) {
      goto err;
    }
  }
  compHuffmanCodes(codeLenCodeLengths, flateMaxCodeLenCodes, &codeLenCodeTab);

  // build the literal and distance code tables
  len = 0;
  repeat = 0;
  i = 0;
  while (i < numLitCodes + numDistCodes) {
    if ((code = getHuffmanCodeWord(&codeLenCodeTab)) == EOF) {
      goto err;
    }
    if (code == 16) {
      if ((repeat = getCodeWord(2)) == EOF) {
        goto err;
      }
      repeat += 3;
      if (i + repeat > numLitCodes + numDistCodes) {
        goto err;
      }
      for (; repeat > 0; --repeat) {
        codeLengths[i++] = len;
      }
    } else if (code == 17) {
      if ((repeat = getCodeWord(3)) == EOF) {
        goto err;
      }
      repeat += 3;
      if (i + repeat > numLitCodes + numDistCodes) {
        goto err;
      }
      len = 0;
      for (; repeat > 0; --repeat) {
        codeLengths[i++] = 0;
      }
    } else if (code == 18) {
      if ((repeat = getCodeWord(7)) == EOF) {
        goto err;
      }
      repeat += 11;
      if (i + repeat > numLitCodes + numDistCodes) {
        goto err;
      }
      len = 0;
      for (; repeat > 0; --repeat) {
        codeLengths[i++] = 0;
      }
    } else {
      codeLengths[i++] = len = code;
    }
  }
  compHuffmanCodes(codeLengths, numLitCodes, &litCodeTab);
  compHuffmanCodes(codeLengths + numLitCodes, numDistCodes, &distCodeTab);

  gfree(codeLenCodeTab.codes);
  return gTrue;

err:
  error(getPos(), "Bad dynamic code table in flate stream");
  gfree(codeLenCodeTab.codes);
  return gFalse;
}

// Convert an array <lengths> of <n> lengths, in value order, into a
// Huffman code lookup table.
void FlateStream::compHuffmanCodes(int *lengths, int n, FlateHuffmanTab *tab) {
  int tabSize, len, code, code2, skip, val, i, t;

  // find max code length
  tab->maxLen = 0;
  for (val = 0; val < n; ++val) {
    if (lengths[val] > tab->maxLen) {
      tab->maxLen = lengths[val];
    }
  }

  // allocate the table
  tabSize = 1 << tab->maxLen;
  tab->codes = (FlateCode *)gmallocn(tabSize, sizeof(FlateCode));

  // clear the table
  for (i = 0; i < tabSize; ++i) {
    tab->codes[i].len = 0;
    tab->codes[i].val = 0;
  }

  // build the table
  for (len = 1, code = 0, skip = 2;
       len <= tab->maxLen;
       ++len, code <<= 1, skip <<= 1) {
    for (val = 0; val < n; ++val) {
      if (lengths[val] == len) {

        // bit-reverse the code
        code2 = 0;
        t = code;
        for (i = 0; i < len; ++i) {
          code2 = (code2 << 1) | (t & 1);
          t >>= 1;
        }

        // fill in the table entries
        for (i = code2; i < tabSize; i += skip) {
          tab->codes[i].len = (Gushort)len;
          tab->codes[i].val = (Gushort)val;
        }

        ++code;
      }
    }
  }
}

int FlateStream::getHuffmanCodeWord(FlateHuffmanTab *tab) {
  FlateCode *code;
  int c;

  while (codeSize < tab->maxLen) {
    if ((c = str->getChar()) == EOF) {
      break;
    }
    codeBuf |= (c & 0xff) << codeSize;
    codeSize += 8;
  }
  code = &tab->codes[codeBuf & ((1 << tab->maxLen) - 1)];
  if (codeSize == 0 || codeSize < code->len || code->len == 0) {
    return EOF;
  }
  codeBuf >>= code->len;
  codeSize -= code->len;
  return (int)code->val;
}

int FlateStream::getCodeWord(int bits) {
  int c;

  while (codeSize < bits) {
    if ((c = str->getChar()) == EOF)
      return EOF;
    codeBuf |= (c & 0xff) << codeSize;
    codeSize += 8;
  }
  c = codeBuf & ((1 << bits) - 1);
  codeBuf >>= bits;
  codeSize -= bits;
  return c;
}

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

EOFStream::EOFStream(Stream *strA):
    FilterStream(strA) {
}

EOFStream::~EOFStream() {
  delete str;
}

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

FixedLengthEncoder::FixedLengthEncoder(Stream *strA, int lengthA):
    FilterStream(strA) {
  length = lengthA;
  count = 0;
}

FixedLengthEncoder::~FixedLengthEncoder() {
  if (str->isEncoder())
    delete str;
}

void FixedLengthEncoder::reset() {
  str->reset();
  count = 0;
}

int FixedLengthEncoder::getChar() {
  if (length >= 0 && count >= length)
    return EOF;
  ++count;
  return str->getChar();
}

int FixedLengthEncoder::lookChar() {
  if (length >= 0 && count >= length)
    return EOF;
  return str->getChar();
}

GBool FixedLengthEncoder::isBinary(GBool last) {
  return str->isBinary(gTrue);
}

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

ASCIIHexEncoder::ASCIIHexEncoder(Stream *strA):
    FilterStream(strA) {
  bufPtr = bufEnd = buf;
  lineLen = 0;
  eof = gFalse;
}

ASCIIHexEncoder::~ASCIIHexEncoder() {
  if (str->isEncoder()) {
    delete str;
  }
}

void ASCIIHexEncoder::reset() {
  str->reset();
  bufPtr = bufEnd = buf;
  lineLen = 0;
  eof = gFalse;
}

GBool ASCIIHexEncoder::fillBuf() {
  static char *hex = "0123456789abcdef";
  int c;

  if (eof) {
    return gFalse;
  }
  bufPtr = bufEnd = buf;
  if ((c = str->getChar()) == EOF) {
    *bufEnd++ = '>';
    eof = gTrue;
  } else {
    if (lineLen >= 64) {
      *bufEnd++ = '\n';
      lineLen = 0;
    }
    *bufEnd++ = hex[(c >> 4) & 0x0f];
    *bufEnd++ = hex[c & 0x0f];
    lineLen += 2;
  }
  return gTrue;
}

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

ASCII85Encoder::ASCII85Encoder(Stream *strA):
    FilterStream(strA) {
  bufPtr = bufEnd = buf;
  lineLen = 0;
  eof = gFalse;
}

ASCII85Encoder::~ASCII85Encoder() {
  if (str->isEncoder())
    delete str;
}

void ASCII85Encoder::reset() {
  str->reset();
  bufPtr = bufEnd = buf;
  lineLen = 0;
  eof = gFalse;
}

GBool ASCII85Encoder::fillBuf() {
  Gulong t;
  char buf1[5];
  int c0, c1, c2, c3;
  int n, i;

  if (eof) {
    return gFalse;
  }
  c0 = str->getChar();
  c1 = str->getChar();
  c2 = str->getChar();
  c3 = str->getChar();
  bufPtr = bufEnd = buf;
  if (c3 == EOF) {
    if (c0 == EOF) {
      n = 0;
      t = 0;
    } else {
      if (c1 == EOF) {
        n = 1;
        t = c0 << 24;
      } else if (c2 == EOF) {
        n = 2;
        t = (c0 << 24) | (c1 << 16);
      } else {
        n = 3;
        t = (c0 << 24) | (c1 << 16) | (c2 << 8);
      }
      for (i = 4; i >= 0; --i) {
        buf1[i] = (char)(t % 85 + 0x21);
        t /= 85;
      }
      for (i = 0; i <= n; ++i) {
        *bufEnd++ = buf1[i];
        if (++lineLen == 65) {
          *bufEnd++ = '\n';
          lineLen = 0;
        }
      }
    }
    *bufEnd++ = '~';
    *bufEnd++ = '>';
    eof = gTrue;
  } else {
    t = (c0 << 24) | (c1 << 16) | (c2 << 8) | c3;
    if (t == 0) {
      *bufEnd++ = 'z';
      if (++lineLen == 65) {
        *bufEnd++ = '\n';
        lineLen = 0;
      }
    } else {
      for (i = 4; i >= 0; --i) {
        buf1[i] = (char)(t % 85 + 0x21);
        t /= 85;
      }
      for (i = 0; i <= 4; ++i) {
        *bufEnd++ = buf1[i];
        if (++lineLen == 65) {
          *bufEnd++ = '\n';
          lineLen = 0;
        }
      }
    }
  }
  return gTrue;
}

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

RunLengthEncoder::RunLengthEncoder(Stream *strA):
    FilterStream(strA) {
  bufPtr = bufEnd = nextEnd = buf;
  eof = gFalse;
}

RunLengthEncoder::~RunLengthEncoder() {
  if (str->isEncoder())
    delete str;
}

void RunLengthEncoder::reset() {
  str->reset();
  bufPtr = bufEnd = nextEnd = buf;
  eof = gFalse;
}

//
// When fillBuf finishes, buf[] looks like this:
//   +-----+--------------+-----------------+--
//   + tag | ... data ... | next 0, 1, or 2 |
//   +-----+--------------+-----------------+--
//    ^                    ^                 ^
//    bufPtr               bufEnd            nextEnd
//
GBool RunLengthEncoder::fillBuf() {
  int c, c1, c2;
  int n;

  // already hit EOF?
  if (eof)
    return gFalse;

  // grab two bytes
  if (nextEnd < bufEnd + 1) {
    if ((c1 = str->getChar()) == EOF) {
      eof = gTrue;
      return gFalse;
    }
  } else {
    c1 = bufEnd[0] & 0xff;
  }
  if (nextEnd < bufEnd + 2) {
    if ((c2 = str->getChar()) == EOF) {
      eof = gTrue;
      buf[0] = 0;
      buf[1] = c1;
      bufPtr = buf;
      bufEnd = &buf[2];
      return gTrue;
    }
  } else {
    c2 = bufEnd[1] & 0xff;
  }

  // check for repeat
  c = 0; // make gcc happy
  if (c1 == c2) {
    n = 2;
    while (n < 128 && (c = str->getChar()) == c1)
      ++n;
    buf[0] = (char)(257 - n);
    buf[1] = c1;
    bufEnd = &buf[2];
    if (c == EOF) {
      eof = gTrue;
    } else if (n < 128) {
      buf[2] = c;
      nextEnd = &buf[3];
    } else {
      nextEnd = bufEnd;
    }

  // get up to 128 chars
  } else {
    buf[1] = c1;
    buf[2] = c2;
    n = 2;
    while (n < 128) {
      if ((c = str->getChar()) == EOF) {
        eof = gTrue;
        break;
      }
      ++n;
      buf[n] = c;
      if (buf[n] == buf[n-1])
        break;
    }
    if (buf[n] == buf[n-1]) {
      buf[0] = (char)(n-2-1);
      bufEnd = &buf[n-1];
      nextEnd = &buf[n+1];
    } else {
      buf[0] = (char)(n-1);
      bufEnd = nextEnd = &buf[n+1];
    }
  }
  bufPtr = buf;
  return gTrue;
}