Home | History | Annotate | Download | only in jbig2 
      1 // Copyright 2014 PDFium Authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style license that can be
      3 // found in the LICENSE file.
      4 
      5 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
      6 
      7 #include "core/fxcodec/jbig2/JBig2_HuffmanTable.h"
      8 
      9 #include <algorithm>
     10 #include <limits>
     11 #include <vector>
     12 
     13 #include "core/fxcodec/jbig2/JBig2_BitStream.h"
     14 #include "core/fxcodec/jbig2/JBig2_Define.h"
     15 #include "core/fxcodec/jbig2/JBig2_HuffmanTable_Standard.h"
     16 #include "core/fxcrt/fx_memory.h"
     17 #include "third_party/base/numerics/safe_math.h"
     18 
     19 CJBig2_HuffmanTable::CJBig2_HuffmanTable(const JBig2TableLine* pTable,
     20                                          uint32_t nLines,
     21                                          bool bHTOOB)
     22     : m_bOK(true), HTOOB(bHTOOB), NTEMP(nLines) {
     23   ParseFromStandardTable(pTable);
     24 }
     25 
     26 CJBig2_HuffmanTable::CJBig2_HuffmanTable(CJBig2_BitStream* pStream)
     27     : HTOOB(false), NTEMP(0) {
     28   m_bOK = ParseFromCodedBuffer(pStream);
     29 }
     30 
     31 CJBig2_HuffmanTable::~CJBig2_HuffmanTable() {}
     32 
     33 void CJBig2_HuffmanTable::ParseFromStandardTable(const JBig2TableLine* pTable) {
     34   PREFLEN.resize(NTEMP);
     35   RANGELEN.resize(NTEMP);
     36   RANGELOW.resize(NTEMP);
     37   for (uint32_t i = 0; i < NTEMP; ++i) {
     38     PREFLEN[i] = pTable[i].PREFLEN;
     39     RANGELEN[i] = pTable[i].RANDELEN;
     40     RANGELOW[i] = pTable[i].RANGELOW;
     41   }
     42   InitCodes();
     43 }
     44 
     45 bool CJBig2_HuffmanTable::ParseFromCodedBuffer(CJBig2_BitStream* pStream) {
     46   unsigned char cTemp;
     47   if (pStream->read1Byte(&cTemp) == -1)
     48     return false;
     49 
     50   HTOOB = !!(cTemp & 0x01);
     51   unsigned char HTPS = ((cTemp >> 1) & 0x07) + 1;
     52   unsigned char HTRS = ((cTemp >> 4) & 0x07) + 1;
     53   uint32_t HTLOW;
     54   uint32_t HTHIGH;
     55   if (pStream->readInteger(&HTLOW) == -1 ||
     56       pStream->readInteger(&HTHIGH) == -1 ||
     57       HTLOW > static_cast<uint32_t>(std::numeric_limits<int>::max()) ||
     58       HTHIGH > static_cast<uint32_t>(std::numeric_limits<int>::max())) {
     59     return false;
     60   }
     61 
     62   const int low = static_cast<int>(HTLOW);
     63   const int high = static_cast<int>(HTHIGH);
     64   if (low > high)
     65     return false;
     66 
     67   ExtendBuffers(false);
     68   pdfium::base::CheckedNumeric<int> cur_low = low;
     69   do {
     70     if ((pStream->readNBits(HTPS, &PREFLEN[NTEMP]) == -1) ||
     71         (pStream->readNBits(HTRS, &RANGELEN[NTEMP]) == -1) ||
     72         (static_cast<size_t>(RANGELEN[NTEMP]) >= 8 * sizeof(cur_low))) {
     73       return false;
     74     }
     75     RANGELOW[NTEMP] = cur_low.ValueOrDie();
     76 
     77     if (RANGELEN[NTEMP] >= 32)
     78       return false;
     79 
     80     cur_low += (1 << RANGELEN[NTEMP]);
     81     if (!cur_low.IsValid())
     82       return false;
     83     ExtendBuffers(true);
     84   } while (cur_low.ValueOrDie() < high);
     85 
     86   if (pStream->readNBits(HTPS, &PREFLEN[NTEMP]) == -1)
     87     return false;
     88 
     89   RANGELEN[NTEMP] = 32;
     90   RANGELOW[NTEMP] = low - 1;
     91   ExtendBuffers(true);
     92 
     93   if (pStream->readNBits(HTPS, &PREFLEN[NTEMP]) == -1)
     94     return false;
     95 
     96   RANGELEN[NTEMP] = 32;
     97   RANGELOW[NTEMP] = high;
     98   ExtendBuffers(true);
     99 
    100   if (HTOOB) {
    101     if (pStream->readNBits(HTPS, &PREFLEN[NTEMP]) == -1)
    102       return false;
    103 
    104     ++NTEMP;
    105   }
    106 
    107   return InitCodes();
    108 }
    109 
    110 bool CJBig2_HuffmanTable::InitCodes() {
    111   int lenmax = 0;
    112   for (uint32_t i = 0; i < NTEMP; ++i)
    113     lenmax = std::max(PREFLEN[i], lenmax);
    114 
    115   CODES.resize(NTEMP);
    116   std::vector<int> LENCOUNT(lenmax + 1);
    117   std::vector<int> FIRSTCODE(lenmax + 1);
    118   for (int len : PREFLEN)
    119     ++LENCOUNT[len];
    120 
    121   FIRSTCODE[0] = 0;
    122   LENCOUNT[0] = 0;
    123   for (int i = 1; i <= lenmax; ++i) {
    124     pdfium::base::CheckedNumeric<int> shifted;
    125     shifted = FIRSTCODE[i - 1] + LENCOUNT[i - 1];
    126     shifted <<= 1;
    127     if (!shifted.IsValid())
    128       return false;
    129 
    130     FIRSTCODE[i] = shifted.ValueOrDie();
    131     int CURCODE = FIRSTCODE[i];
    132     for (uint32_t j = 0; j < NTEMP; ++j) {
    133       if (PREFLEN[j] == i)
    134         CODES[j] = CURCODE++;
    135     }
    136   }
    137 
    138   return true;
    139 }
    140 
    141 void CJBig2_HuffmanTable::ExtendBuffers(bool increment) {
    142   if (increment)
    143     ++NTEMP;
    144 
    145   size_t size = PREFLEN.size();
    146   if (NTEMP < size)
    147     return;
    148 
    149   size += 16;
    150   ASSERT(NTEMP < size);
    151   PREFLEN.resize(size);
    152   RANGELEN.resize(size);
    153   RANGELOW.resize(size);
    154 }
    155