| OLD | NEW |
| 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 #ifndef _JBIG2_ARITHMETIC_DECODER_H_ | 7 #ifndef _JBIG2_ARITHMETIC_DECODER_H_ |
| 8 #define _JBIG2_ARITHMETIC_DECODER_H_ | 8 #define _JBIG2_ARITHMETIC_DECODER_H_ |
| 9 #include "JBig2_Define.h" | 9 #include "JBig2_Define.h" |
| 10 #include "JBig2_BitStream.h" | 10 #include "JBig2_BitStream.h" |
| 11 #include "JBig2_ArithQe.h" | 11 #include "JBig2_ArithQe.h" |
| 12 typedef struct { | 12 typedef struct { |
| 13 unsigned int MPS; | 13 unsigned int MPS; |
| 14 unsigned int I; | 14 unsigned int I; |
| 15 } JBig2ArithCtx; | 15 } JBig2ArithCtx; |
| 16 class CJBig2_ArithDecoder : public CJBig2_Object | 16 class CJBig2_ArithDecoder : public CJBig2_Object { |
| 17 { | 17 public: |
| 18 public: | 18 CJBig2_ArithDecoder(CJBig2_BitStream* pStream); |
| 19 | 19 |
| 20 CJBig2_ArithDecoder(CJBig2_BitStream *pStream); | 20 ~CJBig2_ArithDecoder(); |
| 21 | 21 |
| 22 ~CJBig2_ArithDecoder(); | 22 int DECODE(JBig2ArithCtx* pCX); |
| 23 | 23 |
| 24 int DECODE(JBig2ArithCtx *pCX); | 24 private: |
| 25 private: | 25 void INITDEC(); |
| 26 | 26 |
| 27 void INITDEC(); | 27 void BYTEIN(); |
| 28 | 28 unsigned char B; |
| 29 void BYTEIN(); | 29 unsigned int C; |
| 30 unsigned char B; | 30 unsigned int A; |
| 31 unsigned int C; | 31 unsigned int CT; |
| 32 unsigned int A; | 32 CJBig2_BitStream* m_pStream; |
| 33 unsigned int CT; | |
| 34 CJBig2_BitStream *m_pStream; | |
| 35 }; | 33 }; |
| 36 inline CJBig2_ArithDecoder::CJBig2_ArithDecoder(CJBig2_BitStream *pStream) | 34 inline CJBig2_ArithDecoder::CJBig2_ArithDecoder(CJBig2_BitStream* pStream) { |
| 37 { | 35 m_pStream = pStream; |
| 38 m_pStream = pStream; | 36 INITDEC(); |
| 39 INITDEC(); | |
| 40 } | 37 } |
| 41 inline CJBig2_ArithDecoder::~CJBig2_ArithDecoder() | 38 inline CJBig2_ArithDecoder::~CJBig2_ArithDecoder() { |
| 42 { | |
| 43 } | 39 } |
| 44 inline void CJBig2_ArithDecoder::INITDEC() | 40 inline void CJBig2_ArithDecoder::INITDEC() { |
| 45 { | 41 B = m_pStream->getCurByte_arith(); |
| 42 C = (B ^ 0xff) << 16; |
| 43 ; |
| 44 BYTEIN(); |
| 45 C = C << 7; |
| 46 CT = CT - 7; |
| 47 A = 0x8000; |
| 48 } |
| 49 inline void CJBig2_ArithDecoder::BYTEIN() { |
| 50 unsigned char B1; |
| 51 if (B == 0xff) { |
| 52 B1 = m_pStream->getNextByte_arith(); |
| 53 if (B1 > 0x8f) { |
| 54 CT = 8; |
| 55 } else { |
| 56 m_pStream->incByteIdx(); |
| 57 B = B1; |
| 58 C = C + 0xfe00 - (B << 9); |
| 59 CT = 7; |
| 60 } |
| 61 } else { |
| 62 m_pStream->incByteIdx(); |
| 46 B = m_pStream->getCurByte_arith(); | 63 B = m_pStream->getCurByte_arith(); |
| 47 C = (B ^ 0xff) << 16;; | 64 C = C + 0xff00 - (B << 8); |
| 48 BYTEIN(); | 65 CT = 8; |
| 49 C = C << 7; | 66 } |
| 50 CT = CT - 7; | |
| 51 A = 0x8000; | |
| 52 } | 67 } |
| 53 inline void CJBig2_ArithDecoder::BYTEIN() | 68 inline int CJBig2_ArithDecoder::DECODE(JBig2ArithCtx* pCX) { |
| 54 { | 69 int D; |
| 55 unsigned char B1; | 70 const JBig2ArithQe* qe = &QeTable[pCX->I]; |
| 56 if(B == 0xff) { | 71 A = A - qe->Qe; |
| 57 B1 = m_pStream->getNextByte_arith(); | 72 if ((C >> 16) < A) { |
| 58 if(B1 > 0x8f) { | 73 if (A & 0x8000) { |
| 59 CT = 8; | 74 D = pCX->MPS; |
| 60 } else { | 75 } else { |
| 61 m_pStream->incByteIdx(); | 76 if (A < qe->Qe) { |
| 62 B = B1; | 77 D = 1 - pCX->MPS; |
| 63 C = C + 0xfe00 - (B << 9); | 78 if (qe->nSwitch == 1) { |
| 64 CT = 7; | 79 pCX->MPS = 1 - pCX->MPS; |
| 65 } | 80 } |
| 81 pCX->I = qe->NLPS; |
| 82 } else { |
| 83 D = pCX->MPS; |
| 84 pCX->I = qe->NMPS; |
| 85 } |
| 86 do { |
| 87 if (CT == 0) { |
| 88 BYTEIN(); |
| 89 } |
| 90 A <<= 1; |
| 91 C <<= 1; |
| 92 CT--; |
| 93 } while ((A & 0x8000) == 0); |
| 94 } |
| 95 } else { |
| 96 C -= A << 16; |
| 97 if (A < qe->Qe) { |
| 98 A = qe->Qe; |
| 99 D = pCX->MPS; |
| 100 pCX->I = qe->NMPS; |
| 66 } else { | 101 } else { |
| 67 m_pStream->incByteIdx(); | 102 A = qe->Qe; |
| 68 B = m_pStream->getCurByte_arith(); | 103 D = 1 - pCX->MPS; |
| 69 C = C + 0xff00 - (B << 8); | 104 if (qe->nSwitch == 1) { |
| 70 CT = 8; | 105 pCX->MPS = 1 - pCX->MPS; |
| 106 } |
| 107 pCX->I = qe->NLPS; |
| 71 } | 108 } |
| 72 } | 109 do { |
| 73 inline int CJBig2_ArithDecoder::DECODE(JBig2ArithCtx *pCX) | 110 if (CT == 0) { |
| 74 { | 111 BYTEIN(); |
| 75 int D; | 112 } |
| 76 const JBig2ArithQe * qe = &QeTable[pCX->I]; | 113 A <<= 1; |
| 77 A = A - qe->Qe; | 114 C <<= 1; |
| 78 if((C >> 16) < A) { | 115 CT--; |
| 79 if(A & 0x8000) { | 116 } while ((A & 0x8000) == 0); |
| 80 D = pCX->MPS; | 117 } |
| 81 } else { | 118 return D; |
| 82 if(A < qe->Qe) { | |
| 83 D = 1 - pCX->MPS; | |
| 84 if(qe->nSwitch == 1) { | |
| 85 pCX->MPS = 1 - pCX->MPS; | |
| 86 } | |
| 87 pCX->I = qe->NLPS; | |
| 88 } else { | |
| 89 D = pCX->MPS; | |
| 90 pCX->I = qe->NMPS; | |
| 91 } | |
| 92 do { | |
| 93 if (CT == 0) { | |
| 94 BYTEIN(); | |
| 95 } | |
| 96 A <<= 1; | |
| 97 C <<= 1; | |
| 98 CT--; | |
| 99 } while ((A & 0x8000) == 0); | |
| 100 } | |
| 101 } else { | |
| 102 C -= A << 16; | |
| 103 if(A < qe->Qe) { | |
| 104 A = qe->Qe; | |
| 105 D = pCX->MPS; | |
| 106 pCX->I = qe->NMPS; | |
| 107 } else { | |
| 108 A = qe->Qe; | |
| 109 D = 1 - pCX->MPS; | |
| 110 if(qe->nSwitch == 1) { | |
| 111 pCX->MPS = 1 - pCX->MPS; | |
| 112 } | |
| 113 pCX->I = qe->NLPS; | |
| 114 } | |
| 115 do { | |
| 116 if (CT == 0) { | |
| 117 BYTEIN(); | |
| 118 } | |
| 119 A <<= 1; | |
| 120 C <<= 1; | |
| 121 CT--; | |
| 122 } while ((A & 0x8000) == 0); | |
| 123 } | |
| 124 return D; | |
| 125 } | 119 } |
| 126 #endif | 120 #endif |
| OLD | NEW |