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Split MS-CAB wrapper

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Matt Nadareski
2022-12-26 15:04:17 -08:00
parent bb130849ee
commit fcda1f119b
4 changed files with 526 additions and 520 deletions
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7
BurnOutSharp.Wrappers/MicrosoftCabinet.LZX.cs Normal file
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namespace BurnOutSharp.Wrappers
{
public partial class MicrosoftCabinet : WrapperBase
{
// TODO: Implement LZX decompression
}
}

511
BurnOutSharp.Wrappers/MicrosoftCabinet.MSZIP.cs Normal file
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using System;
using System.Collections.Generic;
using BurnOutSharp.Utilities;
namespace BurnOutSharp.Wrappers
{
public partial class MicrosoftCabinet : WrapperBase
{
#region Constants
/// <summary>
/// Maximum Huffman code bit count
/// </summary>
private const int MAX_BITS = 16;
#endregion
#region Properties
/// <summary>
/// Match lengths for literal codes 257..285
/// </summary>
/// <remarks>Each value here is the lower bound for lengths represented</remarks>
private static Dictionary<int, int> LiteralLengths
{
get
{
// If we have cached length mappings, use those
if (_literalLengths != null)
return _literalLengths;
// Otherwise, build it from scratch
_literalLengths = new Dictionary<int, int>
{
[257] = 3,
[258] = 4,
[259] = 5,
[260] = 6,
[261] = 7,
[262] = 8,
[263] = 9,
[264] = 10,
[265] = 11, // 11,12
[266] = 13, // 13,14
[267] = 15, // 15,16
[268] = 17, // 17,18
[269] = 19, // 19-22
[270] = 23, // 23-26
[271] = 27, // 27-30
[272] = 31, // 31-34
[273] = 35, // 35-42
[274] = 43, // 43-50
[275] = 51, // 51-58
[276] = 59, // 59-66
[277] = 67, // 67-82
[278] = 83, // 83-98
[279] = 99, // 99-114
[280] = 115, // 115-130
[281] = 131, // 131-162
[282] = 163, // 163-194
[283] = 195, // 195-226
[284] = 227, // 227-257
[285] = 258,
};
return _literalLengths;
}
}
/// <summary>
/// Extra bits for literal codes 257..285
/// </summary>
private static Dictionary<int, int> LiteralExtraBits
{
get
{
// If we have cached bit mappings, use those
if (_literalExtraBits != null)
return _literalExtraBits;
// Otherwise, build it from scratch
_literalExtraBits = new Dictionary<int, int>();
// Literal Value 257 - 264, 0 bits
for (int i = 257; i < 265; i++)
_literalExtraBits[i] = 0;
// Literal Value 265 - 268, 1 bit
for (int i = 265; i < 269; i++)
_literalExtraBits[i] = 1;
// Literal Value 269 - 272, 2 bits
for (int i = 269; i < 273; i++)
_literalExtraBits[i] = 2;
// Literal Value 273 - 276, 3 bits
for (int i = 273; i < 277; i++)
_literalExtraBits[i] = 3;
// Literal Value 277 - 280, 4 bits
for (int i = 277; i < 281; i++)
_literalExtraBits[i] = 4;
// Literal Value 281 - 284, 5 bits
for (int i = 281; i < 285; i++)
_literalExtraBits[i] = 5;
// Literal Value 285, 0 bits
_literalExtraBits[285] = 0;
return _literalExtraBits;
}
}
/// <summary>
/// Match offsets for distance codes 0..29
/// </summary>
/// <remarks>Each value here is the lower bound for lengths represented</remarks>
public static readonly int[] DistanceOffsets = new int[30]
{
1, 2, 3, 4, 5, 7, 9, 13, 17, 25,
33, 49, 65, 97, 129, 193, 257, 385, 513, 769,
1025, 1537, 2049, 3073, 4097, 6145, 8193, 12289, 16385, 24577,
};
/// <summary>
/// Extra bits for distance codes 0..29
/// </summary>
private static readonly int[] DistanceExtraBits = new int[30]
{
0, 0, 0, 0, 1, 1, 2, 2, 3, 3,
4, 4, 5, 5, 6, 6, 7, 7, 8, 8,
9, 9, 10, 10, 11, 11, 12, 12, 13, 13,
};
/// <summary>
/// The order of the bit length Huffman code lengths
/// </summary>
private static readonly int[] BitLengthOrder = new int[19]
{
16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15,
};
#endregion
#region Instance Variables
/// <summary>
/// Match lengths for literal codes 257..285
/// </summary>
private static Dictionary<int, int> _literalLengths = null;
/// <summary>
/// Extra bits for literal codes 257..285
/// </summary>
private static Dictionary<int, int> _literalExtraBits = null;
#endregion
#region Parsing
/// <summary>
/// Read the block header from the block data, if possible
/// </summary>
/// <param name="data">BitStream representing the block</param>
/// <param name="offset">Offset within the array to parse</param>
/// <returns>Filled block header on success, null on error</returns>
private static Models.MicrosoftCabinet.MSZIP.BlockHeader AsBlockHeader(BitStream data)
{
// If the data is invalid
if (data == null)
return null;
var header = new Models.MicrosoftCabinet.MSZIP.BlockHeader();
header.Signature = data.ReadAlignedUInt16();
if (header.Signature != 0x4B43)
return null;
return header;
}
/// <summary>
/// Read the deflate block header from the block data, if possible
/// </summary>
/// <param name="data">Byte array representing the block</param>
/// <param name="offset">Offset within the array to parse</param>
/// <returns>Filled deflate block header on success, null on error</returns>
private static Models.MicrosoftCabinet.MSZIP.DeflateBlockHeader AsDeflateBlockHeader(BitStream data)
{
// If the data is invalid
if (data == null)
return null;
var header = new Models.MicrosoftCabinet.MSZIP.DeflateBlockHeader();
header.BFINAL = data.ReadBits(1)[0];
header.BTYPE = (Models.MicrosoftCabinet.DeflateCompressionType)data.ReadBits(2).AsByte();
return header;
}
/// <summary>
/// Read the block header from the block data, if possible
/// </summary>
/// <param name="data">Byte array representing the block</param>
/// <param name="offset">Offset within the array to parse</param>
/// <returns>Filled dynamic Huffman compressed block header on success, null on error</returns>
private static Models.MicrosoftCabinet.MSZIP.DynamicHuffmanCompressedBlockHeader AsDynamicHuffmanCompressedBlockHeader(BitStream data)
{
// If the data is invalid
if (data == null)
return null;
var header = new Models.MicrosoftCabinet.MSZIP.DynamicHuffmanCompressedBlockHeader();
// # of Literal/Length codes - 257
ushort HLIT = (ushort)(data.ReadBits(5).AsUInt16() + 257);
// # of Distance codes - 1
byte HDIST = (byte)(data.ReadBits(5).AsByte() + 1);
// HCLEN, # of Code Length codes - 4
byte HCLEN = (byte)(data.ReadBits(4).AsByte() + 4);
// (HCLEN + 4) x 3 bits: code lengths for the code length
// alphabet given just above
//
// These code lengths are interpreted as 3-bit integers
// (0-7); as above, a code length of 0 means the
// corresponding symbol (literal/ length or distance code
// length) is not used.
int[] bitLengths = new int[19];
for (ulong i = 0; i < HCLEN; i++)
bitLengths[BitLengthOrder[i]] = data.ReadBits(3).AsByte();
// Code length Huffman code
int[] bitLengthTable = CreateTable(bitLengths);
// HLIT + 257 code lengths for the literal/length alphabet,
// encoded using the code length Huffman code
header.LiteralLengths = BuildHuffmanTree(data, HLIT, bitLengthTable);
// HDIST + 1 code lengths for the distance alphabet,
// encoded using the code length Huffman code
header.DistanceCodes = BuildHuffmanTree(data, HDIST, bitLengthTable);
return header;
}
/// <summary>
/// Read the block header from the block data, if possible
/// </summary>
/// <param name="data">Byte array representing the block</param>
/// <param name="offset">Offset within the array to parse</param>
/// <returns>Filled non-compressed block header on success, null on error</returns>
private static Models.MicrosoftCabinet.MSZIP.NonCompressedBlockHeader AsNonCompressedBlockHeader(BitStream data)
{
// If the data is invalid
if (data == null)
return null;
var header = new Models.MicrosoftCabinet.MSZIP.NonCompressedBlockHeader();
header.LEN = data.ReadAlignedUInt16();
header.NLEN = data.ReadAlignedUInt16();
// TODO: Confirm NLEN is 1's compliment of LEN
return header;
}
#endregion
#region Helpers
/// <summary>
/// The alphabet for code lengths is as follows
/// </summary>
private static int[] BuildHuffmanTree(BitStream data, ushort codeCount, int[] codeLengths)
{
// Setup the huffman tree
int[] tree = new int[codeCount];
// Setup the loop variables
int lastCode = 0, repeatLength = 0;
for (ulong i = 0; i < codeCount; i++)
{
int codeLength = codeLengths[data.ReadBits(7).AsUInt16()];
if (codeLengths[codeLength] > 7)
_ = data.ReadBits(codeLengths[codeLength] - 7);
// Represent code lengths of 0 - 15
if (codeLength > 0 && codeLength <= 15)
{
lastCode = codeLength;
tree[i] = codeLength;
}
// Copy the previous code length 3 - 6 times.
// The next 2 bits indicate repeat length (0 = 3, ... , 3 = 6)
// Example: Codes 8, 16 (+2 bits 11), 16 (+2 bits 10) will expand to 12 code lengths of 8 (1 + 6 + 5)
else if (codeLength == 16)
{
repeatLength = data.ReadBits(2).AsByte();
repeatLength += 2;
codeLength = lastCode;
}
// Repeat a code length of 0 for 3 - 10 times.
// (3 bits of length)
else if (codeLength == 17)
{
repeatLength = data.ReadBits(3).AsByte();
repeatLength += 3;
codeLength = 0;
}
// Repeat a code length of 0 for 11 - 138 times
// (7 bits of length)
else if (codeLength == 18)
{
repeatLength = data.ReadBits(7).AsByte();
repeatLength += 11;
codeLength = 0;
}
// Everything else
else
{
throw new ArgumentOutOfRangeException();
}
// If we had a repeat length
for (; repeatLength > 0; repeatLength--)
{
tree[i++] = codeLength;
}
}
return tree;
}
/// <summary>
/// Given this rule, we can define the Huffman code for an alphabet
/// just by giving the bit lengths of the codes for each symbol of
/// the alphabet in order; this is sufficient to determine the
/// actual codes. In our example, the code is completely defined
/// by the sequence of bit lengths (2, 1, 3, 3). The following
/// algorithm generates the codes as integers, intended to be read
/// from most- to least-significant bit. The code lengths are
/// initially in tree[I].Len; the codes are produced in
/// tree[I].Code.
/// </summary>
private static int[] CreateTable(int[] lengths)
{
// Count the number of codes for each code length. Let
// bl_count[N] be the number of codes of length N, N >= 1.
int[] bl_count = new int[259];
for (int i = 0; i < lengths.Length; i++)
{
bl_count[lengths[i]]++;
}
// Find the numerical value of the smallest code for each
// code length.
int[] next_code = new int[MAX_BITS + 1];
int code = 0;
bl_count[0] = 0;
for (int bits = 1; bits <= MAX_BITS; bits++)
{
code = (code + bl_count[bits - 1]) << 1;
next_code[bits] = code;
}
// Assign numerical values to all codes, using consecutive
// values for all codes of the same length with the base
// values determined at step 2. Codes that are never used
// (which have a bit length of zero) must not be assigned a
// value.
int[] distances = new int[lengths.Length];
for (int n = 0; n < lengths.Length; n++)
{
int len = lengths[n];
if (len != 0)
{
distances[n] = next_code[len];
next_code[len]++;
}
}
return distances;
}
#endregion
#region Folders
/// <summary>
/// Decompress MSZIP data
/// </summary>
private byte[] DecompressMSZIPData(byte[] data)
{
// Create the bitstream to read from
var dataStream = new BitStream(data);
// Get the block header
var blockHeader = AsBlockHeader(dataStream);
if (blockHeader == null)
return null;
// Create the output byte array
List<byte> decodedBytes = new List<byte>();
// Create the loop variable block
Models.MicrosoftCabinet.MSZIP.DeflateBlockHeader deflateBlockHeader;
do
{
deflateBlockHeader = AsDeflateBlockHeader(dataStream);
// We should never get a reserved block
if (deflateBlockHeader.BTYPE == Models.MicrosoftCabinet.DeflateCompressionType.Reserved)
throw new Exception();
// If stored with no compression
if (deflateBlockHeader.BTYPE == Models.MicrosoftCabinet.DeflateCompressionType.NoCompression)
{
// Skip any remaining bits in current partially processed byte
dataStream.DiscardBuffer();
// Read the block header
deflateBlockHeader.BlockDataHeader = AsNonCompressedBlockHeader(dataStream);
// Copy LEN bytes of data to output
var header = deflateBlockHeader.BlockDataHeader as Models.MicrosoftCabinet.MSZIP.NonCompressedBlockHeader;
ushort length = header.LEN;
decodedBytes.AddRange(dataStream.ReadAlignedBytes(length));
}
// Otherwise
else
{
// If compressed with dynamic Huffman codes
// read representation of code trees
deflateBlockHeader.BlockDataHeader = deflateBlockHeader.BTYPE == Models.MicrosoftCabinet.DeflateCompressionType.DynamicHuffman
? (Models.MicrosoftCabinet.MSZIP.IBlockDataHeader)AsDynamicHuffmanCompressedBlockHeader(dataStream)
: (Models.MicrosoftCabinet.MSZIP.IBlockDataHeader)new Models.MicrosoftCabinet.MSZIP.FixedHuffmanCompressedBlockHeader();
var header = deflateBlockHeader.BlockDataHeader as Models.MicrosoftCabinet.MSZIP.CompressedBlockHeader;
// 9 bits per entry, 288 max symbols
int[] literalDecodeTable = CreateTable(header.LiteralLengths);
// 6 bits per entry, 32 max symbols
int[] distanceDecodeTable = CreateTable(header.DistanceCodes);
// Loop until end of block code recognized
while (true)
{
// Decode literal/length value from input stream
int symbol = literalDecodeTable[dataStream.ReadBits(9).AsUInt16()];
// Copy value (literal byte) to output stream
if (symbol < 256)
{
decodedBytes.Add((byte)symbol);
}
// End of block (256)
else if (symbol == 256)
{
break;
}
else
{
// Decode distance from input stream
ulong length = dataStream.ReadBits(LiteralExtraBits[symbol]).AsUInt64();
length += (ulong)LiteralLengths[symbol];
int code = distanceDecodeTable[length];
ulong distance = dataStream.ReadBits(DistanceExtraBits[code]).AsUInt64();
distance += (ulong)DistanceOffsets[code];
// Move backwards distance bytes in the output
// stream, and copy length bytes from this
// position to the output stream.
}
}
}
} while (!deflateBlockHeader.BFINAL);
/*
Note that a duplicated string reference may refer to a string
in a previous block; i.e., the backward distance may cross one
or more block boundaries. However a distance cannot refer past
the beginning of the output stream. (An application using a
preset dictionary might discard part of the output stream; a
distance can refer to that part of the output stream anyway)
Note also that the referenced string may overlap the current
position; for example, if the last 2 bytes decoded have values
X and Y, a string reference with <length = 5, distance = 2>
adds X,Y,X,Y,X to the output stream.
*/
return decodedBytes.ToArray();
}
#endregion
}
}

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BurnOutSharp.Wrappers/MicrosoftCabinet.Quantum.cs Normal file
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namespace BurnOutSharp.Wrappers
{
public partial class MicrosoftCabinet : WrapperBase
{
// TODO: Implement Quantum decompression
}
}

521
BurnOutSharp.Wrappers/MicrosoftCabinet.cs
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@@ -2,11 +2,10 @@
using System.Collections.Generic;
using System.IO;
using System.Linq;
using BurnOutSharp.Utilities;
namespace BurnOutSharp.Wrappers
{
public class MicrosoftCabinet : WrapperBase
public partial class MicrosoftCabinet : WrapperBase
{
#region Pass-Through Properties
@@ -194,413 +193,6 @@ namespace BurnOutSharp.Wrappers
#endregion
#region Compression
#region LZX
// TODO: Implement LZX decompression
#endregion
#region MSZIP
#region Constants
/// <summary>
/// Maximum Huffman code bit count
/// </summary>
private const int MAX_BITS = 16;
#endregion
#region Properties
/// <summary>
/// Match lengths for literal codes 257..285
/// </summary>
/// <remarks>Each value here is the lower bound for lengths represented</remarks>
private static Dictionary<int, int> LiteralLengths
{
get
{
// If we have cached length mappings, use those
if (_literalLengths != null)
return _literalLengths;
// Otherwise, build it from scratch
_literalLengths = new Dictionary<int, int>
{
[257] = 3,
[258] = 4,
[259] = 5,
[260] = 6,
[261] = 7,
[262] = 8,
[263] = 9,
[264] = 10,
[265] = 11, // 11,12
[266] = 13, // 13,14
[267] = 15, // 15,16
[268] = 17, // 17,18
[269] = 19, // 19-22
[270] = 23, // 23-26
[271] = 27, // 27-30
[272] = 31, // 31-34
[273] = 35, // 35-42
[274] = 43, // 43-50
[275] = 51, // 51-58
[276] = 59, // 59-66
[277] = 67, // 67-82
[278] = 83, // 83-98
[279] = 99, // 99-114
[280] = 115, // 115-130
[281] = 131, // 131-162
[282] = 163, // 163-194
[283] = 195, // 195-226
[284] = 227, // 227-257
[285] = 258,
};
return _literalLengths;
}
}
/// <summary>
/// Extra bits for literal codes 257..285
/// </summary>
private static Dictionary<int, int> LiteralExtraBits
{
get
{
// If we have cached bit mappings, use those
if (_literalExtraBits != null)
return _literalExtraBits;
// Otherwise, build it from scratch
_literalExtraBits = new Dictionary<int, int>();
// Literal Value 257 - 264, 0 bits
for (int i = 257; i < 265; i++)
_literalExtraBits[i] = 0;
// Literal Value 265 - 268, 1 bit
for (int i = 265; i < 269; i++)
_literalExtraBits[i] = 1;
// Literal Value 269 - 272, 2 bits
for (int i = 269; i < 273; i++)
_literalExtraBits[i] = 2;
// Literal Value 273 - 276, 3 bits
for (int i = 273; i < 277; i++)
_literalExtraBits[i] = 3;
// Literal Value 277 - 280, 4 bits
for (int i = 277; i < 281; i++)
_literalExtraBits[i] = 4;
// Literal Value 281 - 284, 5 bits
for (int i = 281; i < 285; i++)
_literalExtraBits[i] = 5;
// Literal Value 285, 0 bits
_literalExtraBits[285] = 0;
return _literalExtraBits;
}
}
/// <summary>
/// Match offsets for distance codes 0..29
/// </summary>
/// <remarks>Each value here is the lower bound for lengths represented</remarks>
public static readonly int[] DistanceOffsets = new int[30]
{
1, 2, 3, 4, 5, 7, 9, 13, 17, 25,
33, 49, 65, 97, 129, 193, 257, 385, 513, 769,
1025, 1537, 2049, 3073, 4097, 6145, 8193, 12289, 16385, 24577,
};
/// <summary>
/// Extra bits for distance codes 0..29
/// </summary>
private static readonly int[] DistanceExtraBits = new int[30]
{
0, 0, 0, 0, 1, 1, 2, 2, 3, 3,
4, 4, 5, 5, 6, 6, 7, 7, 8, 8,
9, 9, 10, 10, 11, 11, 12, 12, 13, 13,
};
/// <summary>
/// The order of the bit length Huffman code lengths
/// </summary>
private static readonly int[] BitLengthOrder = new int[19]
{
16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15,
};
#endregion
#region Instance Variables
/// <summary>
/// Match lengths for literal codes 257..285
/// </summary>
private static Dictionary<int, int> _literalLengths = null;
/// <summary>
/// Extra bits for literal codes 257..285
/// </summary>
private static Dictionary<int, int> _literalExtraBits = null;
#endregion
#region Parsing
/// <summary>
/// Read the block header from the block data, if possible
/// </summary>
/// <param name="data">BitStream representing the block</param>
/// <param name="offset">Offset within the array to parse</param>
/// <returns>Filled block header on success, null on error</returns>
private static Models.MicrosoftCabinet.MSZIP.BlockHeader AsBlockHeader(BitStream data)
{
// If the data is invalid
if (data == null)
return null;
var header = new Models.MicrosoftCabinet.MSZIP.BlockHeader();
header.Signature = data.ReadAlignedUInt16();
if (header.Signature != 0x4B43)
return null;
return header;
}
/// <summary>
/// Read the deflate block header from the block data, if possible
/// </summary>
/// <param name="data">Byte array representing the block</param>
/// <param name="offset">Offset within the array to parse</param>
/// <returns>Filled deflate block header on success, null on error</returns>
private static Models.MicrosoftCabinet.MSZIP.DeflateBlockHeader AsDeflateBlockHeader(BitStream data)
{
// If the data is invalid
if (data == null)
return null;
var header = new Models.MicrosoftCabinet.MSZIP.DeflateBlockHeader();
header.BFINAL = data.ReadBits(1)[0];
header.BTYPE = (Models.MicrosoftCabinet.DeflateCompressionType)data.ReadBits(2).AsByte();
return header;
}
/// <summary>
/// Read the block header from the block data, if possible
/// </summary>
/// <param name="data">Byte array representing the block</param>
/// <param name="offset">Offset within the array to parse</param>
/// <returns>Filled dynamic Huffman compressed block header on success, null on error</returns>
private static Models.MicrosoftCabinet.MSZIP.DynamicHuffmanCompressedBlockHeader AsDynamicHuffmanCompressedBlockHeader(BitStream data)
{
// If the data is invalid
if (data == null)
return null;
var header = new Models.MicrosoftCabinet.MSZIP.DynamicHuffmanCompressedBlockHeader();
// # of Literal/Length codes - 257
ushort HLIT = (ushort)(data.ReadBits(5).AsUInt16() + 257);
// # of Distance codes - 1
byte HDIST = (byte)(data.ReadBits(5).AsByte() + 1);
// HCLEN, # of Code Length codes - 4
byte HCLEN = (byte)(data.ReadBits(4).AsByte() + 4);
// (HCLEN + 4) x 3 bits: code lengths for the code length
// alphabet given just above
//
// These code lengths are interpreted as 3-bit integers
// (0-7); as above, a code length of 0 means the
// corresponding symbol (literal/ length or distance code
// length) is not used.
int[] bitLengths = new int[19];
for (ulong i = 0; i < HCLEN; i++)
bitLengths[BitLengthOrder[i]] = data.ReadBits(3).AsByte();
// Code length Huffman code
int[] bitLengthTable = CreateTable(bitLengths);
// HLIT + 257 code lengths for the literal/length alphabet,
// encoded using the code length Huffman code
header.LiteralLengths = BuildHuffmanTree(data, HLIT, bitLengthTable);
// HDIST + 1 code lengths for the distance alphabet,
// encoded using the code length Huffman code
header.DistanceCodes = BuildHuffmanTree(data, HDIST, bitLengthTable);
return header;
}
/// <summary>
/// Read the block header from the block data, if possible
/// </summary>
/// <param name="data">Byte array representing the block</param>
/// <param name="offset">Offset within the array to parse</param>
/// <returns>Filled non-compressed block header on success, null on error</returns>
private static Models.MicrosoftCabinet.MSZIP.NonCompressedBlockHeader AsNonCompressedBlockHeader(BitStream data)
{
// If the data is invalid
if (data == null)
return null;
var header = new Models.MicrosoftCabinet.MSZIP.NonCompressedBlockHeader();
header.LEN = data.ReadAlignedUInt16();
header.NLEN = data.ReadAlignedUInt16();
// TODO: Confirm NLEN is 1's compliment of LEN
return header;
}
#endregion
#region Helpers
/// <summary>
/// The alphabet for code lengths is as follows
/// </summary>
private static int[] BuildHuffmanTree(BitStream data, ushort codeCount, int[] codeLengths)
{
// Setup the huffman tree
int[] tree = new int[codeCount];
// Setup the loop variables
int lastCode = 0, repeatLength = 0;
for (ulong i = 0; i < codeCount; i++)
{
int codeLength = codeLengths[data.ReadBits(7).AsUInt16()];
if (codeLengths[codeLength] > 7)
_ = data.ReadBits(codeLengths[codeLength] - 7);
// Represent code lengths of 0 - 15
if (codeLength > 0 && codeLength <= 15)
{
lastCode = codeLength;
tree[i] = codeLength;
}
// Copy the previous code length 3 - 6 times.
// The next 2 bits indicate repeat length (0 = 3, ... , 3 = 6)
// Example: Codes 8, 16 (+2 bits 11), 16 (+2 bits 10) will expand to 12 code lengths of 8 (1 + 6 + 5)
else if (codeLength == 16)
{
repeatLength = data.ReadBits(2).AsByte();
repeatLength += 2;
codeLength = lastCode;
}
// Repeat a code length of 0 for 3 - 10 times.
// (3 bits of length)
else if (codeLength == 17)
{
repeatLength = data.ReadBits(3).AsByte();
repeatLength += 3;
codeLength = 0;
}
// Repeat a code length of 0 for 11 - 138 times
// (7 bits of length)
else if (codeLength == 18)
{
repeatLength = data.ReadBits(7).AsByte();
repeatLength += 11;
codeLength = 0;
}
// Everything else
else
{
throw new ArgumentOutOfRangeException();
}
// If we had a repeat length
for (; repeatLength > 0; repeatLength--)
{
tree[i++] = codeLength;
}
}
return tree;
}
/// <summary>
/// Given this rule, we can define the Huffman code for an alphabet
/// just by giving the bit lengths of the codes for each symbol of
/// the alphabet in order; this is sufficient to determine the
/// actual codes. In our example, the code is completely defined
/// by the sequence of bit lengths (2, 1, 3, 3). The following
/// algorithm generates the codes as integers, intended to be read
/// from most- to least-significant bit. The code lengths are
/// initially in tree[I].Len; the codes are produced in
/// tree[I].Code.
/// </summary>
private static int[] CreateTable(int[] lengths)
{
// Count the number of codes for each code length. Let
// bl_count[N] be the number of codes of length N, N >= 1.
int[] bl_count = new int[259];
for (int i = 0; i < lengths.Length; i++)
{
bl_count[lengths[i]]++;
}
// Find the numerical value of the smallest code for each
// code length.
int[] next_code = new int[MAX_BITS + 1];
int code = 0;
bl_count[0] = 0;
for (int bits = 1; bits <= MAX_BITS; bits++)
{
code = (code + bl_count[bits - 1]) << 1;
next_code[bits] = code;
}
// Assign numerical values to all codes, using consecutive
// values for all codes of the same length with the base
// values determined at step 2. Codes that are never used
// (which have a bit length of zero) must not be assigned a
// value.
int[] distances = new int[lengths.Length];
for (int n = 0; n < lengths.Length; n++)
{
int len = lengths[n];
if (len != 0)
{
distances[n] = next_code[len];
next_code[len]++;
}
}
return distances;
}
#endregion
#endregion
#region Quantum
// TODO: Implement Quantum decompression
#endregion
#endregion
#region Folders
/// <summary>
@@ -659,117 +251,6 @@ namespace BurnOutSharp.Wrappers
return data.ToArray();
}
/// <summary>
/// Decompress MSZIP data
/// </summary>
private byte[] DecompressMSZIPData(byte[] data)
{
// Create the bitstream to read from
var dataStream = new BitStream(data);
// Get the block header
var blockHeader = AsBlockHeader(dataStream);
if (blockHeader == null)
return null;
// Create the output byte array
List<byte> decodedBytes = new List<byte>();
// Create the loop variable block
Models.MicrosoftCabinet.MSZIP.DeflateBlockHeader deflateBlockHeader;
do
{
deflateBlockHeader = AsDeflateBlockHeader(dataStream);
// We should never get a reserved block
if (deflateBlockHeader.BTYPE == Models.MicrosoftCabinet.DeflateCompressionType.Reserved)
throw new Exception();
// If stored with no compression
if (deflateBlockHeader.BTYPE == Models.MicrosoftCabinet.DeflateCompressionType.NoCompression)
{
// Skip any remaining bits in current partially processed byte
dataStream.DiscardBuffer();
// Read the block header
deflateBlockHeader.BlockDataHeader = AsNonCompressedBlockHeader(dataStream);
// Copy LEN bytes of data to output
var header = deflateBlockHeader.BlockDataHeader as Models.MicrosoftCabinet.MSZIP.NonCompressedBlockHeader;
ushort length = header.LEN;
decodedBytes.AddRange(dataStream.ReadAlignedBytes(length));
}
// Otherwise
else
{
// If compressed with dynamic Huffman codes
// read representation of code trees
deflateBlockHeader.BlockDataHeader = deflateBlockHeader.BTYPE == Models.MicrosoftCabinet.DeflateCompressionType.DynamicHuffman
? (Models.MicrosoftCabinet.MSZIP.IBlockDataHeader)AsDynamicHuffmanCompressedBlockHeader(dataStream)
: (Models.MicrosoftCabinet.MSZIP.IBlockDataHeader)new Models.MicrosoftCabinet.MSZIP.FixedHuffmanCompressedBlockHeader();
var header = deflateBlockHeader.BlockDataHeader as Models.MicrosoftCabinet.MSZIP.CompressedBlockHeader;
// 9 bits per entry, 288 max symbols
int[] literalDecodeTable = CreateTable(header.LiteralLengths);
// 6 bits per entry, 32 max symbols
int[] distanceDecodeTable = CreateTable(header.DistanceCodes);
// Loop until end of block code recognized
while (true)
{
// Decode literal/length value from input stream
int symbol = literalDecodeTable[dataStream.ReadBits(9).AsUInt16()];
// Copy value (literal byte) to output stream
if (symbol < 256)
{
decodedBytes.Add((byte)symbol);
}
// End of block (256)
else if (symbol == 256)
{
break;
}
else
{
// Decode distance from input stream
ulong length = dataStream.ReadBits(LiteralExtraBits[symbol]).AsUInt64();
length += (ulong)LiteralLengths[symbol];
int code = distanceDecodeTable[length];
ulong distance = dataStream.ReadBits(DistanceExtraBits[code]).AsUInt64();
distance += (ulong)DistanceOffsets[code];
// Move backwards distance bytes in the output
// stream, and copy length bytes from this
// position to the output stream.
}
}
}
} while (!deflateBlockHeader.BFINAL);
/*
Note that a duplicated string reference may refer to a string
in a previous block; i.e., the backward distance may cross one
or more block boundaries. However a distance cannot refer past
the beginning of the output stream. (An application using a
preset dictionary might discard part of the output stream; a
distance can refer to that part of the output stream anyway)
Note also that the referenced string may overlap the current
position; for example, if the last 2 bytes decoded have values
X and Y, a string reference with <length = 5, distance = 2>
adds X,Y,X,Y,X to the output stream.
*/
return decodedBytes.ToArray();
}
#endregion
#region Files