upgrade to xpdf 3.00.

[swftools.git] / pdf2swf / xpdf / JArithmeticDecoder.cc

diff --git a/pdf2swf/xpdf/JArithmeticDecoder.cc b/pdf2swf/xpdf/JArithmeticDecoder.cc
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+++ b/pdf2swf/xpdf/JArithmeticDecoder.cc
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+//========================================================================
+//
+// JArithmeticDecoder.cc
+//
+// Copyright 2002-2004 Glyph & Cog, LLC
+//
+//========================================================================
+
+#include <aconf.h>
+
+#ifdef USE_GCC_PRAGMAS
+#pragma implementation
+#endif
+
+#include "Object.h"
+#include "Stream.h"
+#include "JArithmeticDecoder.h"
+
+//------------------------------------------------------------------------
+// JArithmeticDecoderStates
+//------------------------------------------------------------------------
+
+JArithmeticDecoderStats::JArithmeticDecoderStats(int contextSizeA) {
+  contextSize = contextSizeA;
+  cxTab = (Guchar *)gmalloc(contextSize * sizeof(Guchar));
+  reset();
+}
+
+JArithmeticDecoderStats::~JArithmeticDecoderStats() {
+  gfree(cxTab);
+}
+
+JArithmeticDecoderStats *JArithmeticDecoderStats::copy() {
+  JArithmeticDecoderStats *stats;
+
+  stats = new JArithmeticDecoderStats(contextSize);
+  memcpy(stats->cxTab, cxTab, contextSize);
+  return stats;
+}
+
+void JArithmeticDecoderStats::reset() {
+  memset(cxTab, 0, contextSize);
+}
+
+void JArithmeticDecoderStats::copyFrom(JArithmeticDecoderStats *stats) {
+  memcpy(cxTab, stats->cxTab, contextSize);
+}
+
+void JArithmeticDecoderStats::setEntry(Guint cx, int i, int mps) {
+  cxTab[cx] = (i << 1) + mps;
+}
+
+//------------------------------------------------------------------------
+// JArithmeticDecoder
+//------------------------------------------------------------------------
+
+Guint JArithmeticDecoder::qeTab[47] = {
+  0x56010000, 0x34010000, 0x18010000, 0x0AC10000,
+  0x05210000, 0x02210000, 0x56010000, 0x54010000,
+  0x48010000, 0x38010000, 0x30010000, 0x24010000,
+  0x1C010000, 0x16010000, 0x56010000, 0x54010000,
+  0x51010000, 0x48010000, 0x38010000, 0x34010000,
+  0x30010000, 0x28010000, 0x24010000, 0x22010000,
+  0x1C010000, 0x18010000, 0x16010000, 0x14010000,
+  0x12010000, 0x11010000, 0x0AC10000, 0x09C10000,
+  0x08A10000, 0x05210000, 0x04410000, 0x02A10000,
+  0x02210000, 0x01410000, 0x01110000, 0x00850000,
+  0x00490000, 0x00250000, 0x00150000, 0x00090000,
+  0x00050000, 0x00010000, 0x56010000
+};
+
+int JArithmeticDecoder::nmpsTab[47] = {
+   1,  2,  3,  4,  5, 38,  7,  8,  9, 10, 11, 12, 13, 29, 15, 16,
+  17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32,
+  33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 45, 46
+};
+
+int JArithmeticDecoder::nlpsTab[47] = {
+   1,  6,  9, 12, 29, 33,  6, 14, 14, 14, 17, 18, 20, 21, 14, 14,
+  15, 16, 17, 18, 19, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29,
+  30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 46
+};
+
+int JArithmeticDecoder::switchTab[47] = {
+  1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0,
+  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
+};
+
+JArithmeticDecoder::JArithmeticDecoder() {
+  str = NULL;
+}
+
+JArithmeticDecoder::~JArithmeticDecoder() {
+  while (dataLen > 0) {
+    readByte();
+  }
+}
+
+inline Guint JArithmeticDecoder::readByte() {
+  if (dataLen == 0) {
+    return 0xff;
+  }
+  if (dataLen > 0) {
+    --dataLen;
+  }
+  return (Guint)str->getChar() & 0xff;
+}
+
+void JArithmeticDecoder::start() {
+  buf0 = readByte();
+  buf1 = readByte();
+
+  // INITDEC
+  c = (buf0 ^ 0xff) << 16;
+  byteIn();
+  c <<= 7;
+  ct -= 7;
+  a = 0x80000000;
+}
+
+int JArithmeticDecoder::decodeBit(Guint context,
+                                 JArithmeticDecoderStats *stats) {
+  int bit;
+  Guint qe;
+  int iCX, mpsCX;
+
+  iCX = stats->cxTab[context] >> 1;
+  mpsCX = stats->cxTab[context] & 1;
+  qe = qeTab[iCX];
+  a -= qe;
+  if (c < a) {
+    if (a & 0x80000000) {
+      bit = mpsCX;
+    } else {
+      // MPS_EXCHANGE
+      if (a < qe) {
+       bit = 1 - mpsCX;
+       if (switchTab[iCX]) {
+         stats->cxTab[context] = (nlpsTab[iCX] << 1) | (1 - mpsCX);
+       } else {
+         stats->cxTab[context] = (nlpsTab[iCX] << 1) | mpsCX;
+       }
+      } else {
+       bit = mpsCX;
+       stats->cxTab[context] = (nmpsTab[iCX] << 1) | mpsCX;
+      }
+      // RENORMD
+      do {
+       if (ct == 0) {
+         byteIn();
+       }
+       a <<= 1;
+       c <<= 1;
+       --ct;
+      } while (!(a & 0x80000000));
+    }
+  } else {
+    c -= a;
+    // LPS_EXCHANGE
+    if (a < qe) {
+      bit = mpsCX;
+      stats->cxTab[context] = (nmpsTab[iCX] << 1) | mpsCX;
+    } else {
+      bit = 1 - mpsCX;
+      if (switchTab[iCX]) {
+       stats->cxTab[context] = (nlpsTab[iCX] << 1) | (1 - mpsCX);
+      } else {
+       stats->cxTab[context] = (nlpsTab[iCX] << 1) | mpsCX;
+      }
+    }
+    a = qe;
+    // RENORMD
+    do {
+      if (ct == 0) {
+       byteIn();
+      }
+      a <<= 1;
+      c <<= 1;
+      --ct;
+    } while (!(a & 0x80000000));
+  }
+  return bit;
+}
+
+int JArithmeticDecoder::decodeByte(Guint context,
+                                  JArithmeticDecoderStats *stats) {
+  int byte;
+  int i;
+
+  byte = 0;
+  for (i = 0; i < 8; ++i) {
+    byte = (byte << 1) | decodeBit(context, stats);
+  }
+  return byte;
+}
+
+GBool JArithmeticDecoder::decodeInt(int *x, JArithmeticDecoderStats *stats) {
+  int s;
+  Guint v;
+  int i;
+
+  prev = 1;
+  s = decodeIntBit(stats);
+  if (decodeIntBit(stats)) {
+    if (decodeIntBit(stats)) {
+      if (decodeIntBit(stats)) {
+       if (decodeIntBit(stats)) {
+         if (decodeIntBit(stats)) {
+           v = 0;
+           for (i = 0; i < 32; ++i) {
+             v = (v << 1) | decodeIntBit(stats);
+           }
+           v += 4436;
+         } else {
+           v = 0;
+           for (i = 0; i < 12; ++i) {
+             v = (v << 1) | decodeIntBit(stats);
+           }
+           v += 340;
+         }
+       } else {
+         v = 0;
+         for (i = 0; i < 8; ++i) {
+           v = (v << 1) | decodeIntBit(stats);
+         }
+         v += 84;
+       }
+      } else {
+       v = 0;
+       for (i = 0; i < 6; ++i) {
+         v = (v << 1) | decodeIntBit(stats);
+       }
+       v += 20;
+      }
+    } else {
+      v = decodeIntBit(stats);
+      v = (v << 1) | decodeIntBit(stats);
+      v = (v << 1) | decodeIntBit(stats);
+      v = (v << 1) | decodeIntBit(stats);
+      v += 4;
+    }
+  } else {
+    v = decodeIntBit(stats);
+    v = (v << 1) | decodeIntBit(stats);
+  }
+
+  if (s) {
+    if (v == 0) {
+      return gFalse;
+    }
+    *x = -(int)v;
+  } else {
+    *x = (int)v;
+  }
+  return gTrue;
+}
+
+int JArithmeticDecoder::decodeIntBit(JArithmeticDecoderStats *stats) {
+  int bit;
+
+  bit = decodeBit(prev, stats);
+  if (prev < 0x100) {
+    prev = (prev << 1) | bit;
+  } else {
+    prev = (((prev << 1) | bit) & 0x1ff) | 0x100;
+  }
+  return bit;
+}
+
+Guint JArithmeticDecoder::decodeIAID(Guint codeLen,
+                                    JArithmeticDecoderStats *stats) {
+  Guint i;
+  int bit;
+
+  prev = 1;
+  for (i = 0; i < codeLen; ++i) {
+    bit = decodeBit(prev, stats);
+    prev = (prev << 1) | bit;
+  }
+  return prev - (1 << codeLen);
+}
+
+void JArithmeticDecoder::byteIn() {
+  if (buf0 == 0xff) {
+    if (buf1 > 0x8f) {
+      ct = 8;
+    } else {
+      buf0 = buf1;
+      buf1 = readByte();
+      c = c + 0xfe00 - (buf0 << 9);
+      ct = 7;
+    }
+  } else {
+    buf0 = buf1;
+    buf1 = readByte();
+    c = c + 0xff00 - (buf0 << 8);
+    ct = 8;
+  }
+}