Index: core/src/fxcodec/jbig2/JBig2_BitStream.cpp |
diff --git a/core/src/fxcodec/jbig2/JBig2_BitStream.cpp b/core/src/fxcodec/jbig2/JBig2_BitStream.cpp |
new file mode 100644 |
index 0000000000000000000000000000000000000000..4a4ed992c7fe387045546d7f4be81b8cd1e699f2 |
--- /dev/null |
+++ b/core/src/fxcodec/jbig2/JBig2_BitStream.cpp |
@@ -0,0 +1,178 @@ |
+// Copyright 2015 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 "JBig2_BitStream.h" |
+ |
+#include <algorithm> |
+ |
+CJBig2_BitStream::CJBig2_BitStream(const uint8_t* pBuffer, FX_DWORD dwLength) |
+ : m_pBuf(pBuffer), m_dwLength(dwLength), m_dwByteIdx(0), m_dwBitIdx(0) { |
+ if (m_dwLength > 256 * 1024 * 1024) { |
+ m_dwLength = 0; |
+ m_pBuf = nullptr; |
+ } |
+} |
+ |
+CJBig2_BitStream::~CJBig2_BitStream() { |
+} |
+ |
+int32_t CJBig2_BitStream::readNBits(FX_DWORD dwBits, FX_DWORD* dwResult) { |
+ FX_DWORD dwBitPos = getBitPos(); |
+ if (dwBitPos > LengthInBits()) |
+ return -1; |
+ |
+ *dwResult = 0; |
+ if (dwBitPos + dwBits <= LengthInBits()) |
+ dwBitPos = dwBits; |
+ else |
+ dwBitPos = LengthInBits() - dwBitPos; |
+ |
+ for (; dwBitPos > 0; --dwBitPos) { |
+ *dwResult = |
+ (*dwResult << 1) | ((m_pBuf[m_dwByteIdx] >> (7 - m_dwBitIdx)) & 0x01); |
+ AdvanceBit(); |
+ } |
+ return 0; |
+} |
+ |
+int32_t CJBig2_BitStream::readNBits(FX_DWORD dwBits, int32_t* nResult) { |
+ FX_DWORD dwBitPos = getBitPos(); |
+ if (dwBitPos > LengthInBits()) |
+ return -1; |
+ |
+ *nResult = 0; |
+ if (dwBitPos + dwBits <= LengthInBits()) |
+ dwBitPos = dwBits; |
+ else |
+ dwBitPos = LengthInBits() - dwBitPos; |
+ |
+ for (; dwBitPos > 0; --dwBitPos) { |
+ *nResult = |
+ (*nResult << 1) | ((m_pBuf[m_dwByteIdx] >> (7 - m_dwBitIdx)) & 0x01); |
+ AdvanceBit(); |
+ } |
+ return 0; |
+} |
+ |
+int32_t CJBig2_BitStream::read1Bit(FX_DWORD* dwResult) { |
+ if (!IsInBound()) |
+ return -1; |
+ |
+ *dwResult = (m_pBuf[m_dwByteIdx] >> (7 - m_dwBitIdx)) & 0x01; |
+ AdvanceBit(); |
+ return 0; |
+} |
+ |
+int32_t CJBig2_BitStream::read1Bit(FX_BOOL* bResult) { |
+ if (!IsInBound()) |
+ return -1; |
+ |
+ *bResult = (m_pBuf[m_dwByteIdx] >> (7 - m_dwBitIdx)) & 0x01; |
+ AdvanceBit(); |
+ return 0; |
+} |
+ |
+int32_t CJBig2_BitStream::read1Byte(uint8_t* cResult) { |
+ if (!IsInBound()) |
+ return -1; |
+ |
+ *cResult = m_pBuf[m_dwByteIdx]; |
+ ++m_dwByteIdx; |
+ return 0; |
+} |
+ |
+int32_t CJBig2_BitStream::readInteger(FX_DWORD* dwResult) { |
+ if (m_dwByteIdx + 3 >= m_dwLength) |
+ return -1; |
+ |
+ *dwResult = (m_pBuf[m_dwByteIdx] << 24) | (m_pBuf[m_dwByteIdx + 1] << 16) | |
+ (m_pBuf[m_dwByteIdx + 2] << 8) | m_pBuf[m_dwByteIdx + 3]; |
+ m_dwByteIdx += 4; |
+ return 0; |
+} |
+ |
+int32_t CJBig2_BitStream::readShortInteger(FX_WORD* dwResult) { |
+ if (m_dwByteIdx + 1 >= m_dwLength) |
+ return -1; |
+ |
+ *dwResult = (m_pBuf[m_dwByteIdx] << 8) | m_pBuf[m_dwByteIdx + 1]; |
+ m_dwByteIdx += 2; |
+ return 0; |
+} |
+ |
+void CJBig2_BitStream::alignByte() { |
+ if (m_dwBitIdx != 0) { |
+ ++m_dwByteIdx; |
+ m_dwBitIdx = 0; |
+ } |
+} |
+ |
+uint8_t CJBig2_BitStream::getCurByte() const { |
+ return IsInBound() ? m_pBuf[m_dwByteIdx] : 0; |
+} |
+ |
+void CJBig2_BitStream::incByteIdx() { |
+ if (IsInBound()) |
+ ++m_dwByteIdx; |
+} |
+ |
+uint8_t CJBig2_BitStream::getCurByte_arith() const { |
+ return IsInBound() ? m_pBuf[m_dwByteIdx] : 0xFF; |
+} |
+ |
+uint8_t CJBig2_BitStream::getNextByte_arith() const { |
+ return m_dwByteIdx + 1 < m_dwLength ? m_pBuf[m_dwByteIdx + 1] : 0xFF; |
+} |
+ |
+FX_DWORD CJBig2_BitStream::getOffset() const { |
+ return m_dwByteIdx; |
+} |
+ |
+void CJBig2_BitStream::setOffset(FX_DWORD dwOffset) { |
+ m_dwByteIdx = std::min(dwOffset, m_dwLength); |
+} |
+ |
+FX_DWORD CJBig2_BitStream::getBitPos() const { |
+ return (m_dwByteIdx << 3) + m_dwBitIdx; |
+} |
+ |
+void CJBig2_BitStream::setBitPos(FX_DWORD dwBitPos) { |
+ m_dwByteIdx = dwBitPos >> 3; |
+ m_dwBitIdx = dwBitPos & 7; |
+} |
+ |
+const uint8_t* CJBig2_BitStream::getBuf() const { |
+ return m_pBuf; |
+} |
+ |
+const uint8_t* CJBig2_BitStream::getPointer() const { |
+ return m_pBuf + m_dwByteIdx; |
+} |
+ |
+void CJBig2_BitStream::offset(FX_DWORD dwOffset) { |
+ m_dwByteIdx += dwOffset; |
+} |
+ |
+FX_DWORD CJBig2_BitStream::getByteLeft() const { |
+ return m_dwLength - m_dwByteIdx; |
+} |
+ |
+void CJBig2_BitStream::AdvanceBit() { |
+ if (m_dwBitIdx == 7) { |
+ ++m_dwByteIdx; |
+ m_dwBitIdx = 0; |
+ } else { |
+ ++m_dwBitIdx; |
+ } |
+} |
+ |
+bool CJBig2_BitStream::IsInBound() const { |
+ return m_dwByteIdx < m_dwLength; |
+} |
+ |
+FX_DWORD CJBig2_BitStream::LengthInBits() const { |
+ return m_dwLength << 3; |
+} |