Files
BinaryObjectScanner/BurnOutSharp/FileType/MicrosoftCAB.Quantum.cs
2022-12-14 13:17:29 -08:00

287 lines
8.7 KiB
C#

using System.Runtime.InteropServices;
/// <see href="http://www.russotto.net/quantumcomp.html"/>
/// <see href="https://handwiki.org/wiki/Software:Quantum_compression"/>
/// <see href="https://archive.org/details/datacompressionc00salo_251/page/n206/mode/2up"/>
/// <see href="https://github.com/kyz/libmspack/blob/master/libmspack/mspack/qtm.h"/>
/// <see href="https://github.com/kyz/libmspack/blob/master/libmspack/mspack/qtmc.c"/>
/// <see href="https://github.com/kyz/libmspack/blob/master/libmspack/mspack/qtmd.c"/>
namespace BurnOutSharp.FileType
{
internal enum SelectorModel
{
/// <summary>
/// Literal model, 64 entries, start at symbol 0
/// </summary>
SELECTOR_0 = 0,
/// <summary>
/// Literal model, 64 entries, start at symbol 64
/// </summary>
SELECTOR_1 = 1,
/// <summary>
/// Literal model, 64 entries, start at symbol 128
/// </summary>
SELECTOR_2 = 2,
/// <summary>
/// Literal model, 64 entries, start at symbol 192
/// </summary>
SELECTOR_3 = 3,
/// <summary>
/// LZ model, 3 character matches, max 24 entries, start at symbol 0
/// </summary>
SELECTOR_4 = 4,
/// <summary>
/// LZ model, 4 character matches, max 36 entries, start at symbol 0
/// </summary>
SELECTOR_5 = 5,
/// <summary>
/// LZ model, 5+ character matches, max 42 entries, start at symbol 0
/// </summary>
SELECTOR_6_POSITION = 6,
/// <summary>
/// LZ model, 5+ character matches, 27 entries, start at symbol 0
/// </summary>
SELECTOR_6_LENGTH = 7,
}
#region LZ Compression Tables
public static class QuantumConstants
{
/// <summary>
/// Base position for each position slot (0..41)
/// Used by selectors 4, 5, and 6
/// </summary>
public static readonly uint[] PositionBaseTable = new uint[]
{
0x000000, 0x000001, 0x000002, 0x000003, 0x000004, 0x000006, 0x000008, 0x00000c,
0x000010, 0x000018, 0x000020, 0x000030, 0x000040, 0x000060, 0x000080, 0x0000c0,
0x000100, 0x000180, 0x000200, 0x000300, 0x000400, 0x000600, 0x000800, 0x000c00,
0x001000, 0x001800, 0x002000, 0x003000, 0x004000, 0x006000, 0x008000, 0x00c000,
0x010000, 0x018000, 0x020000, 0x030000, 0x040000, 0x060000, 0x080000, 0x0c0000,
0x100000, 0x180000,
};
/// <summary>
/// Extra bits for each position slot (0..41)
/// Used by selectors 4, 5, and 6
/// </summary>
public static readonly int[] PositionExtraBitsTable = new int[]
{
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, 14, 14,
15, 15, 16, 16, 17, 17, 18, 18,
19, 19,
};
/// <summary>
/// Base length for each length slot (0..26)
/// Used by selector 6
/// </summary>
public static readonly byte[] LengthBaseTable = new byte[]
{
0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x08,
0x0a, 0x0c, 0x0e, 0x12, 0x16, 0x1a, 0x1e, 0x26,
0x2e, 0x36, 0x3e, 0x4e, 0x5e, 0x6e, 0x7e, 0x9e,
0xbe, 0xde, 0xfe
};
/// <summary>
/// Extra bits for each length slot (0..26)
/// Used by selector 6
/// </summary>
public static readonly int[] LengthExtraBitsTable = new int[]
{
0, 0, 0, 0, 0, 0, 1, 1,
1, 1, 2, 2, 2, 2, 3, 3,
3, 3, 4, 4, 4, 4, 5, 5,
5, 5, 0,
};
/// <summary>
/// Number of position slots for (tsize - 10)
/// </summary>
public static readonly int[] NumberOfPositionSlots = new int[]
{
20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42,
};
}
#endregion
/// <summary>
/// Quantum archive file structure
/// </summary>
[StructLayout(LayoutKind.Sequential)]
public class QuantumArchive
{
/// <summary>
/// Quantum signature: 0x44 0x53
/// </summary>
public ushort Signature;
/// <summary>
/// Quantum major version number
/// </summary>
public byte MajorVersion;
/// <summary>
/// Quantum minor version number
/// </summary>
public byte MinorVersion;
/// <summary>
/// Number of files within this archive
/// </summary>
public ushort FileCount;
/// <summary>
/// Table size required for decompression
/// </summary>
public byte TableSize;
/// <summary>
/// Compression flags
/// </summary>
public byte CompressionFlags;
/// <summary>
/// This is immediately followed by the list of files
/// </summary>
public QuantumFileDescriptor[] FileList;
// Immediately following the list of files is the compressed data.
}
/// <remarks>
/// Strings are prefixed with their length. If the length is less than
/// 128 then it is stored directly in one byte. If it is greater than 127
/// then the high bit of the first byte is set to 1 and the remaining
/// fifteen bits contain the actual length in big-endian format.
/// </remarks>
public class QuantumFileDescriptor
{
/// <summary>
/// File name, variable length string, not zero-terminated
/// </summary>
public string FileName;
/// <summary>
/// Comment field, variable length string, not zero-terminated
/// </summary>
public string CommentField;
/// <summary>
/// Fully expanded file size in bytes
/// </summary>
public uint ExpandedFileSize;
/// <summary>
/// File time (DOS format)
/// </summary>
public ushort FileTime;
/// <summary>
/// File date (DOS format)
/// </summary>
public ushort FileDate;
}
public static class QuantumCompressor
{
// TODO: Determine how these values are set
private static uint CS_C = 0;
private static uint CS_H = 0;
private static uint CS_L = 0;
/// <summary>
/// Get frequency from code
/// </summary>
public static ushort GetFrequency(ushort totfreq)
{
uint range = ((CS_H - CS_L) & 0xFFFF) + 1;
uint freq = ((CS_C - CS_L + 1) * totfreq - 1) / range;
return (ushort)(freq & 0xFFFF);
}
/// <summary>
/// The decoder renormalization loop
/// </summary>
public static int GetCode(int cumfreqm1, int cumfreq, int totfreq)
{
uint range = (CS_H - CS_L) + 1;
CS_H = CS_L + (uint)((cumfreqm1 * range) / totfreq) - 1;
CS_L = CS_L + (uint)((cumfreq * range) / totfreq);
while (true)
{
if ((CS_L & 0x8000) != (CS_H & 0x8000))
{
if ((CS_L & 0x4000) != 0 && (CS_H & 0x4000) == 0)
{
// Underflow case
CS_C ^= 0x4000;
CS_L &= 0x3FFF;
CS_H |= 0x4000;
}
else
{
break;
}
}
CS_L <<= 1;
CS_H = (CS_H << 1) | 1;
CS_C = (CS_C << 1) | 0; // TODO: Figure out what `getbit()` is and replace the placeholder `0`
}
// TODO: Figure out what is supposed to return here
return 0;
}
public static int GetSymbol(QuantumModel model)
{
int freq = GetFrequency(model.Symbols[0].CumulativeFrequency);
int i = 1;
for (; i < model.Entries; i++)
{
if (model.Symbols[i].CumulativeFrequency <= freq)
break;
}
int sym = model.Symbols[i - 1].Symbol;
GetCode(model.Symbols[i - 1].CumulativeFrequency, model.Symbols[i].CumulativeFrequency, model.Symbols[0].CumulativeFrequency);
// TODO: Figure out what `update_model` does
//update_model(model, i);
return sym;
}
}
public class QuantumModelSymbol
{
public ushort Symbol { get; private set; }
public ushort CumulativeFrequency { get; private set; }
}
public class QuantumModel
{
public int Entries { get; set; }
public QuantumModelSymbol[] Symbols { get; set; }
}
}