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author | Dan Sinclair <dsinclair@chromium.org> | 2016-03-14 13:35:12 -0400 |
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committer | Dan Sinclair <dsinclair@chromium.org> | 2016-03-14 13:35:12 -0400 |
commit | 764ec513eecbebd12781bcc96ce81ed5e736ee92 (patch) | |
tree | 12763fde4be1f10ea1183d92185917b2b587e00b /core/fxcodec/jbig2/JBig2_ArithDecoder.cpp | |
parent | 97da97662417085774f75c26e535c6fbe70266ae (diff) | |
download | pdfium-764ec513eecbebd12781bcc96ce81ed5e736ee92.tar.xz |
Move core/src/ up to core/.
This CL moves the core/src/ files up to core/ and fixes up the include guards,
includes and build files.
R=tsepez@chromium.org
Review URL: https://codereview.chromium.org/1800523005 .
Diffstat (limited to 'core/fxcodec/jbig2/JBig2_ArithDecoder.cpp')
-rw-r--r-- | core/fxcodec/jbig2/JBig2_ArithDecoder.cpp | 120 |
1 files changed, 120 insertions, 0 deletions
diff --git a/core/fxcodec/jbig2/JBig2_ArithDecoder.cpp b/core/fxcodec/jbig2/JBig2_ArithDecoder.cpp new file mode 100644 index 0000000000..1673110c7e --- /dev/null +++ b/core/fxcodec/jbig2/JBig2_ArithDecoder.cpp @@ -0,0 +1,120 @@ +// Copyright 2014 PDFium Authors. All rights reserved. +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. + +// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com + +#include "core/fxcodec/jbig2/JBig2_ArithDecoder.h" + +#include "core/fxcodec/jbig2/JBig2_BitStream.h" +#include "core/include/fxcrt/fx_basic.h" + +namespace { + +struct JBig2ArithQe { + unsigned int Qe; + unsigned int NMPS; + unsigned int NLPS; + unsigned int nSwitch; +}; + +const JBig2ArithQe kQeTable[] = { + // Stupid hack to keep clang-format from reformatting this badly. + {0x5601, 1, 1, 1}, {0x3401, 2, 6, 0}, {0x1801, 3, 9, 0}, + {0x0AC1, 4, 12, 0}, {0x0521, 5, 29, 0}, {0x0221, 38, 33, 0}, + {0x5601, 7, 6, 1}, {0x5401, 8, 14, 0}, {0x4801, 9, 14, 0}, + {0x3801, 10, 14, 0}, {0x3001, 11, 17, 0}, {0x2401, 12, 18, 0}, + {0x1C01, 13, 20, 0}, {0x1601, 29, 21, 0}, {0x5601, 15, 14, 1}, + {0x5401, 16, 14, 0}, {0x5101, 17, 15, 0}, {0x4801, 18, 16, 0}, + {0x3801, 19, 17, 0}, {0x3401, 20, 18, 0}, {0x3001, 21, 19, 0}, + {0x2801, 22, 19, 0}, {0x2401, 23, 20, 0}, {0x2201, 24, 21, 0}, + {0x1C01, 25, 22, 0}, {0x1801, 26, 23, 0}, {0x1601, 27, 24, 0}, + {0x1401, 28, 25, 0}, {0x1201, 29, 26, 0}, {0x1101, 30, 27, 0}, + {0x0AC1, 31, 28, 0}, {0x09C1, 32, 29, 0}, {0x08A1, 33, 30, 0}, + {0x0521, 34, 31, 0}, {0x0441, 35, 32, 0}, {0x02A1, 36, 33, 0}, + {0x0221, 37, 34, 0}, {0x0141, 38, 35, 0}, {0x0111, 39, 36, 0}, + {0x0085, 40, 37, 0}, {0x0049, 41, 38, 0}, {0x0025, 42, 39, 0}, + {0x0015, 43, 40, 0}, {0x0009, 44, 41, 0}, {0x0005, 45, 42, 0}, + {0x0001, 45, 43, 0}, {0x5601, 46, 46, 0}}; + +const unsigned int kDefaultAValue = 0x8000; + +int DecodeNMPS(JBig2ArithCtx* pCX, const JBig2ArithQe& qe) { + pCX->I = qe.NMPS; + return pCX->MPS; +} + +int DecodeNLPS(JBig2ArithCtx* pCX, const JBig2ArithQe& qe) { + // TODO(thestig): |D|, |MPS| and friends probably should be booleans. + int D = 1 - pCX->MPS; + if (qe.nSwitch == 1) + pCX->MPS = 1 - pCX->MPS; + pCX->I = qe.NLPS; + return D; +} + +} // namespace + +CJBig2_ArithDecoder::CJBig2_ArithDecoder(CJBig2_BitStream* pStream) + : m_pStream(pStream) { + m_B = m_pStream->getCurByte_arith(); + m_C = (m_B ^ 0xff) << 16; + BYTEIN(); + m_C = m_C << 7; + m_CT = m_CT - 7; + m_A = kDefaultAValue; +} + +CJBig2_ArithDecoder::~CJBig2_ArithDecoder() {} + +int CJBig2_ArithDecoder::DECODE(JBig2ArithCtx* pCX) { + if (!pCX || pCX->I >= FX_ArraySize(kQeTable)) + return 0; + + const JBig2ArithQe& qe = kQeTable[pCX->I]; + m_A -= qe.Qe; + if ((m_C >> 16) < m_A) { + if (m_A & kDefaultAValue) + return pCX->MPS; + + const int D = m_A < qe.Qe ? DecodeNLPS(pCX, qe) : DecodeNMPS(pCX, qe); + ReadValueA(); + return D; + } + + m_C -= m_A << 16; + const int D = m_A < qe.Qe ? DecodeNMPS(pCX, qe) : DecodeNLPS(pCX, qe); + m_A = qe.Qe; + ReadValueA(); + return D; +} + +void CJBig2_ArithDecoder::BYTEIN() { + unsigned char B1; + if (m_B == 0xff) { + B1 = m_pStream->getNextByte_arith(); + if (B1 > 0x8f) { + m_CT = 8; + } else { + m_pStream->incByteIdx(); + m_B = B1; + m_C = m_C + 0xfe00 - (m_B << 9); + m_CT = 7; + } + } else { + m_pStream->incByteIdx(); + m_B = m_pStream->getCurByte_arith(); + m_C = m_C + 0xff00 - (m_B << 8); + m_CT = 8; + } +} + +void CJBig2_ArithDecoder::ReadValueA() { + do { + if (m_CT == 0) + BYTEIN(); + m_A <<= 1; + m_C <<= 1; + --m_CT; + } while ((m_A & kDefaultAValue) == 0); +} |