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/src/fxcodec/jbig2/JBig2_HuffmanTable.h"
8
9 #include <algorithm>
10 #include <vector>
11
12 #include "core/include/fxcrt/fx_memory.h"
13 #include "core/src/fxcodec/jbig2/JBig2_BitStream.h"
14 #include "core/src/fxcodec/jbig2/JBig2_Define.h"
15 #include "core/src/fxcodec/jbig2/JBig2_HuffmanTable_Standard.h"
16
CJBig2_HuffmanTable(const JBig2TableLine * pTable,FX_DWORD nLines,bool bHTOOB)17 CJBig2_HuffmanTable::CJBig2_HuffmanTable(const JBig2TableLine* pTable,
18 FX_DWORD nLines,
19 bool bHTOOB)
20 : m_bOK(true), HTOOB(bHTOOB), NTEMP(nLines) {
21 ParseFromStandardTable(pTable);
22 }
23
CJBig2_HuffmanTable(CJBig2_BitStream * pStream)24 CJBig2_HuffmanTable::CJBig2_HuffmanTable(CJBig2_BitStream* pStream)
25 : HTOOB(false), NTEMP(0) {
26 m_bOK = ParseFromCodedBuffer(pStream);
27 }
28
~CJBig2_HuffmanTable()29 CJBig2_HuffmanTable::~CJBig2_HuffmanTable() {
30 }
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 (FX_DWORD 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 FX_DWORD HTLOW;
53 FX_DWORD 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 int cur_low = low;
66 do {
67 if ((pStream->readNBits(HTPS, &PREFLEN[NTEMP]) == -1) ||
68 (pStream->readNBits(HTRS, &RANGELEN[NTEMP]) == -1)) {
69 return false;
70 }
71 RANGELOW[NTEMP] = cur_low;
72 cur_low += (1 << RANGELEN[NTEMP]);
73 ExtendBuffers(true);
74 } while (cur_low < high);
75
76 if (pStream->readNBits(HTPS, &PREFLEN[NTEMP]) == -1)
77 return false;
78
79 RANGELEN[NTEMP] = 32;
80 RANGELOW[NTEMP] = low - 1;
81 ExtendBuffers(true);
82
83 if (pStream->readNBits(HTPS, &PREFLEN[NTEMP]) == -1)
84 return false;
85
86 RANGELEN[NTEMP] = 32;
87 RANGELOW[NTEMP] = high;
88 ExtendBuffers(true);
89
90 if (HTOOB) {
91 if (pStream->readNBits(HTPS, &PREFLEN[NTEMP]) == -1)
92 return false;
93
94 ++NTEMP;
95 }
96
97 InitCodes();
98 return true;
99 }
100
InitCodes()101 void CJBig2_HuffmanTable::InitCodes() {
102 int lenmax = 0;
103 for (FX_DWORD i = 0; i < NTEMP; ++i)
104 lenmax = std::max(PREFLEN[i], lenmax);
105
106 CODES.resize(NTEMP);
107 std::vector<int> LENCOUNT(lenmax + 1);
108 std::vector<int> FIRSTCODE(lenmax + 1);
109 for (int len : PREFLEN)
110 ++LENCOUNT[len];
111
112 FIRSTCODE[0] = 0;
113 LENCOUNT[0] = 0;
114 for (int i = 1; i <= lenmax; ++i) {
115 FIRSTCODE[i] = (FIRSTCODE[i - 1] + LENCOUNT[i - 1]) << 1;
116 int CURCODE = FIRSTCODE[i];
117 for (FX_DWORD j = 0; j < NTEMP; ++j) {
118 if (PREFLEN[j] == i)
119 CODES[j] = CURCODE++;
120 }
121 }
122 }
123
ExtendBuffers(bool increment)124 void CJBig2_HuffmanTable::ExtendBuffers(bool increment) {
125 if (increment)
126 ++NTEMP;
127
128 size_t size = PREFLEN.size();
129 if (NTEMP < size)
130 return;
131
132 size += 16;
133 ASSERT(NTEMP < size);
134 PREFLEN.resize(size);
135 RANGELEN.resize(size);
136 RANGELOW.resize(size);
137 }
138