Initial community commit

Src/external_dependencies/openmpt-trunk/soundlib/OggStream.cpp

@@ -0,0 +1,213 @@
+/*
+ * OggStream.cpp
+ * -------------
+ * Purpose: Basic Ogg stream parsing functionality
+ * Notes  : (currently none)
+ * Authors: OpenMPT Devs
+ * The OpenMPT source code is released under the BSD license. Read LICENSE for more details.
+ */
+
+#include "stdafx.h"
+#include "OggStream.h"
+#include "mpt/crc/crc.hpp"
+#include "../common/FileReader.h"
+
+
+OPENMPT_NAMESPACE_BEGIN
+
+
+namespace Ogg
+{
+
+
+uint16 PageInfo::GetPagePhysicalSize() const
+{
+	uint16 size = 0;
+	size += sizeof(PageHeader);
+	size += header.page_segments;
+	for(uint8 segment = 0; segment < header.page_segments; ++segment)
+	{
+		size += segment_table[segment];
+	}
+	return size;
+}
+
+
+uint16 PageInfo::GetPageHeaderSize() const
+{
+	uint16 size = 0;
+	size += sizeof(PageHeader);
+	size += header.page_segments;
+	return size;
+}
+
+
+uint16 PageInfo::GetPageDataSize() const
+{
+	uint16 size = 0;
+	for(uint8 segment = 0; segment < header.page_segments; ++segment)
+	{
+		size += segment_table[segment];
+	}
+	return size;
+}
+
+
+bool AdvanceToPageMagic(FileReader &file)
+{
+#if MPT_COMPILER_MSVC
+#pragma warning(push)
+#pragma warning(disable:4127) // conditional expression is constant
+#endif // MPT_COMPILER_MSVC
+	while(true)
+#if MPT_COMPILER_MSVC
+#pragma warning(pop)
+#endif // MPT_COMPILER_MSVC
+	{
+		if(!file.CanRead(4))
+		{
+			return false;
+		}
+		if(file.ReadMagic("OggS"))
+		{
+			file.SkipBack(4);
+			return true;
+		}
+		file.Skip(1);
+	}
+}
+
+
+bool ReadPage(FileReader &file, PageInfo &pageInfo, std::vector<uint8> *pageData)
+{
+	pageInfo = PageInfo();
+	if(pageData)
+	{
+		(*pageData).clear();
+	}
+	if(!file.ReadMagic("OggS"))
+	{
+		return false;
+	}
+	file.SkipBack(4);
+	FileReader filePageReader = file; // do not modify original file read position
+	if(!filePageReader.ReadStruct(pageInfo.header))
+	{
+		return false;
+	}
+	if(!filePageReader.CanRead(pageInfo.header.page_segments))
+	{
+		return false;
+	}
+	uint16 pageDataSize = 0;
+	for(uint8 segment = 0; segment < pageInfo.header.page_segments; ++segment)
+	{
+		pageInfo.segment_table[segment] = filePageReader.ReadIntLE<uint8>();
+		pageDataSize += pageInfo.segment_table[segment];
+	}
+	if(!filePageReader.CanRead(pageDataSize))
+	{
+		return false;
+	}
+	if(pageData)
+	{
+		filePageReader.ReadVector(*pageData, pageDataSize);
+	} else
+	{
+		filePageReader.Skip(pageDataSize);
+	}
+	filePageReader.SkipBack(pageInfo.GetPagePhysicalSize());
+	{
+		mpt::crc32_ogg calculatedCRC;
+		uint8 rawHeader[sizeof(PageHeader)];
+		MemsetZero(rawHeader);
+		filePageReader.ReadArray(rawHeader);
+		std::memset(rawHeader + 22, 0, 4); // clear out old crc
+		calculatedCRC.process(rawHeader, rawHeader + sizeof(rawHeader));
+		filePageReader.Skip(pageInfo.header.page_segments);
+		calculatedCRC.process(pageInfo.segment_table, pageInfo.segment_table + pageInfo.header.page_segments);
+		if(pageData)
+		{
+			filePageReader.Skip(pageDataSize);
+			calculatedCRC.process(*pageData);
+		} else
+		{
+			FileReader pageDataReader = filePageReader.ReadChunk(pageDataSize);
+			auto pageDataView = pageDataReader.GetPinnedView();
+			calculatedCRC.process(pageDataView.GetSpan());
+		}
+		if(calculatedCRC != pageInfo.header.CRC_checksum)
+		{
+			return false;
+		}
+	}
+	file.Skip(pageInfo.GetPagePhysicalSize());
+	return true;
+}
+
+
+bool ReadPage(FileReader &file, PageInfo &pageInfo, std::vector<uint8> &pageData)
+{
+	return ReadPage(file, pageInfo, &pageData);
+}
+
+
+bool ReadPage(FileReader &file)
+{
+	PageInfo pageInfo;
+	return ReadPage(file, pageInfo);
+}
+
+
+bool ReadPageAndSkipJunk(FileReader &file, PageInfo &pageInfo, std::vector<uint8> &pageData)
+{
+	pageInfo = PageInfo();
+	pageData.clear();
+#if MPT_COMPILER_MSVC
+#pragma warning(push)
+#pragma warning(disable:4127) // conditional expression is constant
+#endif // MPT_COMPILER_MSVC
+	while(true)
+#if MPT_COMPILER_MSVC
+#pragma warning(pop)
+#endif // MPT_COMPILER_MSVC
+	{
+		if(!AdvanceToPageMagic(file))
+		{
+			return false;
+		}
+		if(ReadPage(file, pageInfo, pageData))
+		{
+			return true;
+		} else
+		{
+			pageInfo = PageInfo();
+			pageData.clear();
+		}
+		file.Skip(1);
+	}
+}
+
+
+bool UpdatePageCRC(PageInfo &pageInfo, const std::vector<uint8> &pageData)
+{
+	if(pageData.size() != pageInfo.GetPageDataSize())
+	{
+		return false;
+	}
+	mpt::crc32_ogg crc;
+	pageInfo.header.CRC_checksum = 0;
+	char rawHeader[sizeof(PageHeader)];
+	std::memcpy(rawHeader, &pageInfo.header, sizeof(PageHeader));
+	crc.process(rawHeader, rawHeader + sizeof(PageHeader));
+	crc.process(pageInfo.segment_table, pageInfo.segment_table + pageInfo.header.page_segments);
+	crc.process(pageData);
+	pageInfo.header.CRC_checksum = crc;
+	return true;
+}
+
+
+} // namespace Ogg
+
+
+OPENMPT_NAMESPACE_END