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1 // Copyright 2014 PDFium Authors. All rights reserved. | 1 // Copyright 2014 PDFium Authors. All rights reserved. |
2 // Use of this source code is governed by a BSD-style license that can be | 2 // Use of this source code is governed by a BSD-style license that can be |
3 // found in the LICENSE file. | 3 // found in the LICENSE file. |
4 | 4 |
5 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com | 5 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com |
6 | 6 |
7 #include "JBig2_HuffmanDecoder.h" | 7 #include "JBig2_HuffmanDecoder.h" |
8 | 8 |
9 #include "JBig2_Define.h" | 9 #include "JBig2_Define.h" |
10 | 10 |
11 CJBig2_HuffmanDecoder::CJBig2_HuffmanDecoder(CJBig2_BitStream* pStream) { | 11 CJBig2_HuffmanDecoder::CJBig2_HuffmanDecoder(CJBig2_BitStream* pStream) |
12 m_pStream = pStream; | 12 : m_pStream(pStream) { |
13 } | 13 } |
| 14 |
14 CJBig2_HuffmanDecoder::~CJBig2_HuffmanDecoder() {} | 15 CJBig2_HuffmanDecoder::~CJBig2_HuffmanDecoder() {} |
| 16 |
15 int CJBig2_HuffmanDecoder::decodeAValue(CJBig2_HuffmanTable* pTable, | 17 int CJBig2_HuffmanDecoder::decodeAValue(CJBig2_HuffmanTable* pTable, |
16 int* nResult) { | 18 int* nResult) { |
17 int i; | |
18 int nVal = 0; | 19 int nVal = 0; |
19 int nBits = 0; | 20 int nBits = 0; |
20 FX_DWORD nTmp; | |
21 while (1) { | 21 while (1) { |
22 if (m_pStream->read1Bit(&nTmp) == -1) { | 22 FX_DWORD nTmp; |
| 23 if (m_pStream->read1Bit(&nTmp) == -1) |
23 return -1; | 24 return -1; |
24 } | 25 |
25 nVal = (nVal << 1) | nTmp; | 26 nVal = (nVal << 1) | nTmp; |
26 nBits++; | 27 ++nBits; |
27 for (i = 0; i < pTable->NTEMP; i++) { | 28 for (FX_DWORD i = 0; i < pTable->NTEMP; ++i) { |
28 if ((pTable->PREFLEN[i] == nBits) && (pTable->CODES[i] == nVal)) { | 29 if ((pTable->PREFLEN[i] == nBits) && (pTable->CODES[i] == nVal)) { |
29 if ((pTable->HTOOB == 1) && (i == pTable->NTEMP - 1)) { | 30 if ((pTable->HTOOB == 1) && (i == pTable->NTEMP - 1)) |
30 return JBIG2_OOB; | 31 return JBIG2_OOB; |
| 32 |
| 33 if (m_pStream->readNBits(pTable->RANGELEN[i], &nTmp) == -1) |
| 34 return -1; |
| 35 |
| 36 if (pTable->HTOOB) { |
| 37 if (i == pTable->NTEMP - 3) |
| 38 *nResult = pTable->RANGELOW[i] - nTmp; |
| 39 else |
| 40 *nResult = pTable->RANGELOW[i] + nTmp; |
| 41 return 0; |
31 } | 42 } |
32 if (m_pStream->readNBits(pTable->RANGELEN[i], &nTmp) == -1) { | 43 |
33 return -1; | 44 if (i == pTable->NTEMP - 2) |
34 } | 45 *nResult = pTable->RANGELOW[i] - nTmp; |
35 if (pTable->HTOOB) { | 46 else |
36 if (i == pTable->NTEMP - 3) { | 47 *nResult = pTable->RANGELOW[i] + nTmp; |
37 *nResult = pTable->RANGELOW[i] - nTmp; | 48 return 0; |
38 return 0; | |
39 } else { | |
40 *nResult = pTable->RANGELOW[i] + nTmp; | |
41 return 0; | |
42 } | |
43 } else { | |
44 if (i == pTable->NTEMP - 2) { | |
45 *nResult = pTable->RANGELOW[i] - nTmp; | |
46 return 0; | |
47 } else { | |
48 *nResult = pTable->RANGELOW[i] + nTmp; | |
49 return 0; | |
50 } | |
51 } | |
52 } | 49 } |
53 } | 50 } |
54 } | 51 } |
55 return -2; | 52 return -2; |
56 } | 53 } |
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