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 <vector>
11
12 #include "core/fxcodec/jbig2/JBig2_BitStream.h"
13 #include "core/fxcodec/jbig2/JBig2_Define.h"
14 #include "core/fxcodec/jbig2/JBig2_HuffmanTable_Standard.h"
15 #include "core/fxcrt/fx_memory.h"
16 #include "third_party/base/numerics/safe_math.h"
17
CJBig2_HuffmanTable(const JBig2TableLine * pTable,uint32_t nLines,bool bHTOOB)18 CJBig2_HuffmanTable::CJBig2_HuffmanTable(const JBig2TableLine* pTable,
19 uint32_t nLines,
20 bool bHTOOB)
21 : m_bOK(true), HTOOB(bHTOOB), NTEMP(nLines) {
22 ParseFromStandardTable(pTable);
23 }
24
CJBig2_HuffmanTable(CJBig2_BitStream * pStream)25 CJBig2_HuffmanTable::CJBig2_HuffmanTable(CJBig2_BitStream* pStream)
26 : HTOOB(false), NTEMP(0) {
27 m_bOK = ParseFromCodedBuffer(pStream);
28 }
29
~CJBig2_HuffmanTable()30 CJBig2_HuffmanTable::~CJBig2_HuffmanTable() {}
31
ParseFromStandardTable(const JBig2TableLine * pTable)32 void CJBig2_HuffmanTable::ParseFromStandardTable(const JBig2TableLine* pTable) {
33 PREFLEN.resize(NTEMP);
34 RANGELEN.resize(NTEMP);
35 RANGELOW.resize(NTEMP);
36 for (uint32_t i = 0; i < NTEMP; ++i) {
37 PREFLEN[i] = pTable[i].PREFLEN;
38 RANGELEN[i] = pTable[i].RANDELEN;
39 RANGELOW[i] = pTable[i].RANGELOW;
40 }
41 InitCodes();
42 }
43
ParseFromCodedBuffer(CJBig2_BitStream * pStream)44 bool CJBig2_HuffmanTable::ParseFromCodedBuffer(CJBig2_BitStream* pStream) {
45 unsigned char cTemp;
46 if (pStream->read1Byte(&cTemp) == -1)
47 return false;
48
49 HTOOB = !!(cTemp & 0x01);
50 unsigned char HTPS = ((cTemp >> 1) & 0x07) + 1;
51 unsigned char HTRS = ((cTemp >> 4) & 0x07) + 1;
52 uint32_t HTLOW;
53 uint32_t HTHIGH;
54 if (pStream->readInteger(&HTLOW) == -1 ||
55 pStream->readInteger(&HTHIGH) == -1) {
56 return false;
57 }
58
59 const int low = static_cast<int>(HTLOW);
60 const int high = static_cast<int>(HTHIGH);
61 if (low > high)
62 return false;
63
64 ExtendBuffers(false);
65 pdfium::base::CheckedNumeric<int> cur_low = low;
66 do {
67 if ((pStream->readNBits(HTPS, &PREFLEN[NTEMP]) == -1) ||
68 (pStream->readNBits(HTRS, &RANGELEN[NTEMP]) == -1) ||
69 (static_cast<size_t>(RANGELEN[NTEMP]) >= 8 * sizeof(cur_low))) {
70 return false;
71 }
72 RANGELOW[NTEMP] = cur_low.ValueOrDie();
73 cur_low += (1 << RANGELEN[NTEMP]);
74 if (!cur_low.IsValid())
75 return false;
76 ExtendBuffers(true);
77 } while (cur_low.ValueOrDie() < high);
78
79 if (pStream->readNBits(HTPS, &PREFLEN[NTEMP]) == -1)
80 return false;
81
82 RANGELEN[NTEMP] = 32;
83 RANGELOW[NTEMP] = low - 1;
84 ExtendBuffers(true);
85
86 if (pStream->readNBits(HTPS, &PREFLEN[NTEMP]) == -1)
87 return false;
88
89 RANGELEN[NTEMP] = 32;
90 RANGELOW[NTEMP] = high;
91 ExtendBuffers(true);
92
93 if (HTOOB) {
94 if (pStream->readNBits(HTPS, &PREFLEN[NTEMP]) == -1)
95 return false;
96
97 ++NTEMP;
98 }
99
100 InitCodes();
101 return true;
102 }
103
InitCodes()104 void CJBig2_HuffmanTable::InitCodes() {
105 int lenmax = 0;
106 for (uint32_t i = 0; i < NTEMP; ++i)
107 lenmax = std::max(PREFLEN[i], lenmax);
108
109 CODES.resize(NTEMP);
110 std::vector<int> LENCOUNT(lenmax + 1);
111 std::vector<int> FIRSTCODE(lenmax + 1);
112 for (int len : PREFLEN)
113 ++LENCOUNT[len];
114
115 FIRSTCODE[0] = 0;
116 LENCOUNT[0] = 0;
117 for (int i = 1; i <= lenmax; ++i) {
118 FIRSTCODE[i] = (FIRSTCODE[i - 1] + LENCOUNT[i - 1]) << 1;
119 int CURCODE = FIRSTCODE[i];
120 for (uint32_t j = 0; j < NTEMP; ++j) {
121 if (PREFLEN[j] == i)
122 CODES[j] = CURCODE++;
123 }
124 }
125 }
126
ExtendBuffers(bool increment)127 void CJBig2_HuffmanTable::ExtendBuffers(bool increment) {
128 if (increment)
129 ++NTEMP;
130
131 size_t size = PREFLEN.size();
132 if (NTEMP < size)
133 return;
134
135 size += 16;
136 ASSERT(NTEMP < size);
137 PREFLEN.resize(size);
138 RANGELEN.resize(size);
139 RANGELOW.resize(size);
140 }
141