jbig2stream.cc

来自「source code: Covert TXT to PDF」· CC 代码 · 共 2,563 行 · 第 1/5 页

  {   102, 6,  5,              0x037 },
  {   134, 6,  6,              0x038 },
  {   198, 6,  7,              0x039 },
  {   326, 6,  8,              0x03a },
  {   582, 6,  9,              0x03b },
  {  1094, 6, 10,              0x03c },
  {   -21, 7,  4,              0x07a },
  {    -4, 7,  0,              0x07b },
  {     4, 7,  0,              0x07c },
  {  2118, 7, 11,              0x07d },
  {    -5, 8,  0,              0x0fc },
  {     5, 8,  0,              0x0fd },
  {   -22, 8, jbig2HuffmanLOW, 0x0fe },
  {  4166, 8, 32,              0x0ff },
  {     0, 0, jbig2HuffmanEOT, 0     }
};

JBIG2HuffmanTable huffTableK[] = {
  {     1, 1,  0,              0x000 },
  {     2, 2,  1,              0x002 },
  {     4, 4,  0,              0x00c },
  {     5, 4,  1,              0x00d },
  {     7, 5,  1,              0x01c },
  {     9, 5,  2,              0x01d },
  {    13, 6,  2,              0x03c },
  {    17, 7,  2,              0x07a },
  {    21, 7,  3,              0x07b },
  {    29, 7,  4,              0x07c },
  {    45, 7,  5,              0x07d },
  {    77, 7,  6,              0x07e },
  {   141, 7, 32,              0x07f },
  {     0, 0, jbig2HuffmanEOT, 0     }
};

JBIG2HuffmanTable huffTableL[] = {
  {     1, 1,  0,              0x000 },
  {     2, 2,  0,              0x002 },
  {     3, 3,  1,              0x006 },
  {     5, 5,  0,              0x01c },
  {     6, 5,  1,              0x01d },
  {     8, 6,  1,              0x03c },
  {    10, 7,  0,              0x07a },
  {    11, 7,  1,              0x07b },
  {    13, 7,  2,              0x07c },
  {    17, 7,  3,              0x07d },
  {    25, 7,  4,              0x07e },
  {    41, 8,  5,              0x0fe },
  {    73, 8, 32,              0x0ff },
  {     0, 0, jbig2HuffmanEOT, 0     }
};

JBIG2HuffmanTable huffTableM[] = {
  {     1, 1,  0,              0x000 },
  {     2, 3,  0,              0x004 },
  {     7, 3,  3,              0x005 },
  {     3, 4,  0,              0x00c },
  {     5, 4,  1,              0x00d },
  {     4, 5,  0,              0x01c },
  {    15, 6,  1,              0x03a },
  {    17, 6,  2,              0x03b },
  {    21, 6,  3,              0x03c },
  {    29, 6,  4,              0x03d },
  {    45, 6,  5,              0x03e },
  {    77, 7,  6,              0x07e },
  {   141, 7, 32,              0x07f },
  {     0, 0, jbig2HuffmanEOT, 0     }
};

JBIG2HuffmanTable huffTableN[] = {
  {     0, 1,  0,              0x000 },
  {    -2, 3,  0,              0x004 },
  {    -1, 3,  0,              0x005 },
  {     1, 3,  0,              0x006 },
  {     2, 3,  0,              0x007 },
  {     0, 0, jbig2HuffmanEOT, 0     }
};

JBIG2HuffmanTable huffTableO[] = {
  {     0, 1,  0,              0x000 },
  {    -1, 3,  0,              0x004 },
  {     1, 3,  0,              0x005 },
  {    -2, 4,  0,              0x00c },
  {     2, 4,  0,              0x00d },
  {    -4, 5,  1,              0x01c },
  {     3, 5,  1,              0x01d },
  {    -8, 6,  2,              0x03c },
  {     5, 6,  2,              0x03d },
  {   -24, 7,  4,              0x07c },
  {     9, 7,  4,              0x07d },
  {   -25, 7, jbig2HuffmanLOW, 0x07e },
  {    25, 7, 32,              0x07f },
  {     0, 0, jbig2HuffmanEOT, 0     }
};

//------------------------------------------------------------------------
// JBIG2HuffmanDecoder
//------------------------------------------------------------------------

class JBIG2HuffmanDecoder {
public:

  JBIG2HuffmanDecoder();
  ~JBIG2HuffmanDecoder();
  void setStream(Stream *strA) { str = strA; }

  void reset();

  // Returns false for OOB, otherwise sets *<x> and returns true.
  GBool decodeInt(int *x, JBIG2HuffmanTable *table);

  Guint readBits(Guint n);
  Guint readBit();

  // Sort the table by prefix length and assign prefix values.
  void buildTable(JBIG2HuffmanTable *table, Guint len);

private:

  Stream *str;
  Guint buf;
  Guint bufLen;
};

JBIG2HuffmanDecoder::JBIG2HuffmanDecoder() {
  str = NULL;
  reset();
}

JBIG2HuffmanDecoder::~JBIG2HuffmanDecoder() {
}

void JBIG2HuffmanDecoder::reset() {
  buf = 0;
  bufLen = 0;
}

//~ optimize this
GBool JBIG2HuffmanDecoder::decodeInt(int *x, JBIG2HuffmanTable *table) {
  Guint i, len, prefix;

  i = 0;
  len = 0;
  prefix = 0;
  while (table[i].rangeLen != jbig2HuffmanEOT) {
    //~ if buildTable removes the entries with prefixLen=0, this is unneeded
    if (table[i].prefixLen > 0) {
      while (len < table[i].prefixLen) {
	prefix = (prefix << 1) | readBit();
	++len;
      }
      if (prefix == table[i].prefix) {
	if (table[i].rangeLen == jbig2HuffmanOOB) {
	  return gFalse;
	}
	if (table[i].rangeLen == jbig2HuffmanLOW) {
	  *x = table[i].val - readBits(32);
	} else if (table[i].rangeLen > 0) {
	  *x = table[i].val + readBits(table[i].rangeLen);
	} else {
	  *x = table[i].val;
	}
	return gTrue;
      }
    }
    ++i;
  }
  return gFalse;
}

Guint JBIG2HuffmanDecoder::readBits(Guint n) {
  Guint x, mask, nLeft;

  mask = (n == 32) ? 0xffffffff : ((1 << n) - 1);
  if (bufLen >= n) {
    x = (buf >> (bufLen - n)) & mask;
    bufLen -= n;
  } else {
    x = buf & ((1 << bufLen) - 1);
    nLeft = n - bufLen;
    bufLen = 0;
    while (nLeft >= 8) {
      x = (x << 8) | (str->getChar() & 0xff);
      nLeft -= 8;
    }
    if (nLeft > 0) {
      buf = str->getChar();
      bufLen = 8 - nLeft;
      x = (x << nLeft) | ((buf >> bufLen) & ((1 << nLeft) - 1));
    }
  }
  return x;
}

Guint JBIG2HuffmanDecoder::readBit() {
  if (bufLen == 0) {
    buf = str->getChar();
    bufLen = 8;
  }
  --bufLen;
  return (buf >> bufLen) & 1;
}

static int cmpHuffmanTabEntries(const void *p1, const void *p2) {
  return ((JBIG2HuffmanTable *)p1)->prefixLen
         - ((JBIG2HuffmanTable *)p2)->prefixLen;
}

//~ should remove entries with prefixLen = 0
void JBIG2HuffmanDecoder::buildTable(JBIG2HuffmanTable *table, Guint len) {
  Guint i, prefix;

  qsort(table, len, sizeof(JBIG2HuffmanTable), &cmpHuffmanTabEntries);
  for (i = 0; i < len && table[i].prefixLen == 0; ++i) {
    table[i].prefix = 0;
  }
  prefix = 0;
  table[i++].prefix = prefix++;
  for (; i < len; ++i) {
    prefix <<= table[i].prefixLen - table[i-1].prefixLen;
    table[i].prefix = prefix++;
  }
}

//------------------------------------------------------------------------
// JBIG2MMRDecoder
//------------------------------------------------------------------------

class JBIG2MMRDecoder {
public:

  JBIG2MMRDecoder();
  ~JBIG2MMRDecoder();
  void setStream(Stream *strA) { str = strA; }
  void reset();
  int get2DCode();
  int getBlackCode();
  int getWhiteCode();
  Guint get24Bits();
  void skipTo(Guint length);

private:

  Stream *str;
  Guint buf;
  Guint bufLen;
  Guint nBytesRead;
};

JBIG2MMRDecoder::JBIG2MMRDecoder() {
  str = NULL;
  reset();
}

JBIG2MMRDecoder::~JBIG2MMRDecoder() {
}

void JBIG2MMRDecoder::reset() {
  buf = 0;
  bufLen = 0;
  nBytesRead = 0;
}

int JBIG2MMRDecoder::get2DCode() {
  CCITTCode *p;

  if (bufLen == 0) {
    buf = str->getChar() & 0xff;
    bufLen = 8;
    ++nBytesRead;
    p = &twoDimTab1[(buf >> 1) & 0x7f];
  } else if (bufLen == 8) {
    p = &twoDimTab1[(buf >> 1) & 0x7f];
  } else {
    p = &twoDimTab1[(buf << (7 - bufLen)) & 0x7f];
    if (p->bits < 0 || p->bits > (int)bufLen) {
      buf = (buf << 8) | (str->getChar() & 0xff);
      bufLen += 8;
      ++nBytesRead;
      p = &twoDimTab1[(buf >> (bufLen - 7)) & 0x7f];
    }
  }
  if (p->bits < 0) {
    error(str->getPos(), "Bad two dim code in JBIG2 MMR stream");
    return 0;
  }
  bufLen -= p->bits;
  return p->n;
}

int JBIG2MMRDecoder::getWhiteCode() {
  CCITTCode *p;
  Guint code;

  if (bufLen == 0) {
    buf = str->getChar() & 0xff;
    bufLen = 8;
    ++nBytesRead;
  }
  while (1) {
    if (bufLen > 7 && ((buf >> (bufLen - 7)) & 0x7f) == 0) {
      if (bufLen <= 12) {
	code = buf << (12 - bufLen);
      } else {
	code = buf >> (bufLen - 12);
      }
      p = &whiteTab1[code & 0x1f];
    } else {
      if (bufLen <= 9) {
	code = buf << (9 - bufLen);
      } else {
	code = buf >> (bufLen - 9);
      }
      p = &whiteTab2[code & 0x1ff];
    }
    if (p->bits > 0 && p->bits < (int)bufLen) {
      bufLen -= p->bits;
      return p->n;
    }
    if (bufLen >= 12) {
      break;
    }
    buf = (buf << 8) | (str->getChar() & 0xff);
    bufLen += 8;
    ++nBytesRead;
  }
  error(str->getPos(), "Bad white code in JBIG2 MMR stream");
  // eat a bit and return a positive number so that the caller doesn't
  // go into an infinite loop
  --bufLen;
  return 1;
}

int JBIG2MMRDecoder::getBlackCode() {
  CCITTCode *p;
  Guint code;

  if (bufLen == 0) {
    buf = str->getChar() & 0xff;
    bufLen = 8;
    ++nBytesRead;
  }
  while (1) {
    if (bufLen > 6 && ((buf >> (bufLen - 6)) & 0x3f) == 0) {
      if (bufLen <= 13) {
	code = buf << (13 - bufLen);
      } else {
	code = buf >> (bufLen - 13);
      }
      p = &blackTab1[code & 0x7f];
    } else if (bufLen > 4 && ((buf >> (bufLen - 4)) & 0x0f) == 0) {
      if (bufLen <= 12) {
	code = buf << (12 - bufLen);
      } else {
	code = buf >> (bufLen - 12);
      }
      p = &blackTab2[(code & 0xff) - 64];
    } else {
      if (bufLen <= 6) {
	code = buf << (6 - bufLen);
      } else {
	code = buf >> (bufLen - 6);
      }
      p = &blackTab3[code & 0x3f];
    }
    if (p->bits > 0 && p->bits < (int)bufLen) {
      bufLen -= p->bits;
      return p->n;
    }
    if (bufLen >= 13) {
      break;
    }
    buf = (buf << 8) | (str->getChar() & 0xff);
    bufLen += 8;
    ++nBytesRead;
  }
  error(str->getPos(), "Bad black code in JBIG2 MMR stream");
  // eat a bit and return a positive number so that the caller doesn't
  // go into an infinite loop
  --bufLen;
  return 1;
}

Guint JBIG2MMRDecoder::get24Bits() {
  while (bufLen < 24) {
    buf = (buf << 8) | (str->getChar() & 0xff);
    bufLen += 8;
    ++nBytesRead;
  }
  return (buf >> (bufLen - 24)) & 0xffffff;
}

void JBIG2MMRDecoder::skipTo(Guint length) {
  while (nBytesRead < length) {
    str->getChar();
    ++nBytesRead;
  }
}

//------------------------------------------------------------------------
// JBIG2Segment
//------------------------------------------------------------------------

enum JBIG2SegmentType {
  jbig2SegBitmap,
  jbig2SegSymbolDict,
  jbig2SegPatternDict,
  jbig2SegCodeTable
};

class JBIG2Segment {
public:

  JBIG2Segment(Guint segNumA) { segNum = segNumA; }
  virtual ~JBIG2Segment() {}
  void setSegNum(Guint segNumA) { segNum = segNumA; }
  Guint getSegNum() { return segNum; }
  virtual JBIG2SegmentType getType() = 0;

private:

  Guint segNum;
};

//------------------------------------------------------------------------
// JBIG2Bitmap
//------------------------------------------------------------------------

class JBIG2Bitmap: public JBIG2Segment {
public:

  JBIG2Bitmap(Guint segNumA, int wA, int hA);
  virtual ~JBIG2Bitmap();
  virtual JBIG2SegmentType getType() { return jbig2SegBitmap; }
  JBIG2Bitmap *copy() { return new JBIG2Bitmap(0, this); }
  JBIG2Bitmap *getSlice(Guint x, Guint y, Guint wA, Guint hA);
  void expand(int newH, Guint pixel);
  void clearToZero();
  void clearToOne();
  int getWidth() { return w; }
  int getHeight() { return h; }
  int getPixel(int x, int y)
    { return (x < 0 || x >= w || y < 0 || y >= h) ? 0 :
             (data[y * line + (x >> 3)] >> (7 - (x & 7))) & 1; }
  void setPixel(int x, int y)
    { data[y * line + (x >> 3)] |= 1 << (7 - (x & 7)); }
  void clearPixel(int x, int y)
    { data[y * line + (x >> 3)] &= 0x7f7f >> (x & 7); }
  void duplicateRow(int yDest, int ySrc);
  void combine(JBIG2Bitmap *bitmap, int x, int y, Guint combOp);
  Guchar *getDataPtr() { return data; }
  int getDataSize() { return h * line; }

private:

  JBIG2Bitmap(Guint segNumA, JBIG2Bitmap *bitmap);

  int w, h, line;
  Guchar *data;
};

JBIG2Bitmap::JBIG2Bitmap(Guint segNumA, int wA, int hA):
  JBIG2Segment(segNumA)
{
  w = wA;
  h = hA;
  line = (wA + 7) >> 3;
  data = (Guchar *)gmalloc(h * line);
}

JBIG2Bitmap::JBIG2Bitmap(Guint segNumA, JBIG2Bitmap *bitmap):
  JBIG2Segment(segNumA)
{
  w = bitmap->w;
  h = bitmap->h;
  line = bitmap->line;
  data = (Guchar *)gmalloc(h * line);
  memcpy(data, bitmap->data, h * line);
}

JBIG2Bitmap::~JBIG2Bitmap() {
  gfree(data);
}

//~ optimize this
JBIG2Bitmap *JBIG2Bitmap::getSlice(Guint x, Guint y, Guint wA, Guint hA) {
  JBIG2Bitmap *slice;
  Guint xx, yy;

  slice = new JBIG2Bitmap(0, wA, hA);
  slice->clearToZero();
  for (yy = 0; yy < hA; ++yy) {
    for (xx = 0; xx < wA; ++xx) {
      if (getPixel(x + xx, y + yy)) {
	slice->setPixel(xx, yy);
      }
    }
  }
  return slice;
}

void JBIG2Bitmap::expand(int newH, Guint pixel) {
  if (newH <= h) {
    return;
  }
  data = (Guchar *)grealloc(data, newH * line);
  if (pixel) {
    memset(data + h * line, 0xff, (newH - h) * line);
  } else {
    memset(data + h * line, 0x00, (newH - h) * line);
  }
  h = newH;
}