private void InitialiseEncodingTable()
{
#region Patterns
var patterns = new List <int>
{
0x6cc, 0x66c, 0x666, 0x498, 0x48c, 0x44c, 0x4c8, 0x4c4, 0x464, 0x648, 0x644, 0x624,
0x59c, 0x4dc, 0x4ce, 0x5cc, 0x4ec, 0x4e6, 0x672, 0x65c, 0x64e, 0x6e4, 0x674, 0x76e,
0x74c, 0x72c, 0x726, 0x764, 0x734, 0x732, 0x6d8, 0x6c6, 0x636, 0x518, 0x458, 0x446,
0x588, 0x468, 0x462, 0x688, 0x628, 0x622, 0x5b8, 0x58e, 0x46e, 0x5d8, 0x5c6, 0x476,
0x776, 0x68e, 0x62e, 0x6e8, 0x6e2, 0x6ee, 0x758, 0x746, 0x716, 0x768, 0x762, 0x71a,
0x77a, 0x642, 0x78a, 0x530, 0x50c, 0x4b0, 0x486, 0x42c, 0x426, 0x590, 0x584, 0x4d0,
0x4c2, 0x434, 0x432, 0x612, 0x650, 0x7ba, 0x614, 0x47a, 0x53c, 0x4bc, 0x49e, 0x5e4,
0x4f4, 0x4f2, 0x7a4, 0x794, 0x792, 0x6de, 0x6f6, 0x7b6, 0x578, 0x51e, 0x45e, 0x5e8,
0x5e2, 0x7a8, 0x7a2, 0x5de, 0x5ee, 0x75e, 0x7ae
};
#endregion
EncodingTable = new EncodingTable();
EncodingTable.AddRange(patterns.Select(p => new CodeWord(p)));
// Add StartCodes
EncodingTable.Add(new StartWordA());
EncodingTable.Add(new StartWordB());
EncodingTable.Add(new StartWordC());
}
/// <summary>
/// Compresses the file stored in the <paramref name="path" /> and stores compressed file it the
/// <paramref name="filePart" />.
/// </summary>
/// <param name="path">The path to the file to be compressed.</param>
/// <param name="filePart">The archive part to store the compressed file in.</param>
/// <param name="frequencyTable">The frequency table to be saved to the archive.</param>
private void CompressFile(string path, PackagePart filePart, out FrequencyTable frequencyTable)
{
/* open the file */
var fileStream = new FileStream(path, FileMode.Open, FileAccess.Read, FileShare.Read, BufferSize);
/* find frequencies of bytes in the file */
OnStateChange("counting up frequencies of bytes");
frequencyTable = new FrequencyTable(fileStream);
frequencyTable.SubscribeToUpdates(OnProgressChange);
frequencyTable.CountFrequencies();
/* rewind the position of the stream to use this stream once again */
fileStream.Position = 0;
/* build the Huffman tree based on the counted frequencies */
OnStateChange("building the Huffman tree");
var huffmanTree = new HuffmanTree(frequencyTable);
/* get the Huffman code from the tree */
OnStateChange("retrieving the Huffman code");
var encodingTable = new EncodingTable(huffmanTree);
/* get the file part's stream */
var filePartStream = new BufferedStream(filePart.GetStream(), BufferSize);
/* encode the file */
OnStateChange("compressing the file");
var encoder = new Encoder(fileStream, filePartStream, encodingTable);
encoder.SubscribeToUpdates(OnProgressChange);
encoder.Encode();
/* dispose unused streams */
fileStream.Close();
filePartStream.Close();
}
public static byte[] GetBytes(string s)
{
byte[] returnData = new byte[s.Length];
for (int i = 0; i < s.Length; i++)
{
returnData[i] = EncodingTable.FirstOrDefault(et => et.Character == s[i].ToString()).Index;
}
return(returnData);
}
public void Dispose()
{
EncodingTable.Clear();
EncodingTable = null;
TextMatrices[0].Clear();
TextMatrices[1].Clear();
TextMatrices[2].Clear();
TextMatrices[0] = null;
TextMatrices[1] = null;
TextMatrices[2] = null;
}
public void EncodingTest3()
{
GenerateByteStream("EncodingTest3", 15, 16, false);
var fileStream = new FileStream("EncodingTest3", FileMode.Open, FileAccess.Read);
var bytes = new byte[fileStream.Length];
fileStream.Read(bytes, 0, (int)fileStream.Length);
var frequencyTable = new FrequencyTable(bytes);
var huffmanTree = new HuffmanTree(frequencyTable);
var encodingTable = new EncodingTable(huffmanTree);
Console.WriteLine(encodingTable.ToString());
}
Dictionary <char, int> ParseCmapTable(Stream stream, BinaryReader reader, TableHeader header)
{
stream.Position = header.Offset + 2;
int tableCount = reader.ReadUInt16();
var tableList = new List <EncodingTable>();
for (int i = 0; i < tableCount; i++)
{
var table = new EncodingTable()
{
PlatformId = reader.ReadUInt16(),
EncodingId = reader.ReadUInt16(),
Offset = reader.ReadUInt32(),
};
tableList.Add(table);
}
EncodingTable unicodeTable = tableList.Find(table => table.PlatformId == 3 && table.EncodingId == 1);
stream.Position = header.Offset + unicodeTable.Offset + 2;
int length = reader.ReadUInt16();
stream.Position += 2;
int segCount = reader.ReadUInt16() / 2;
stream.Position += 6;
var endCode = new int[segCount];
for (int i = 0; i < segCount; i++)
{
endCode[i] = reader.ReadUInt16();
}
stream.Position += 2;
var startCode = new int[segCount];
for (int i = 0; i < segCount; i++)
{
startCode[i] = reader.ReadUInt16();
}
var idDelta = new int[segCount];
for (int i = 0; i < segCount; i++)
{
idDelta[i] = reader.ReadInt16();
}
long offset = stream.Position;
var idRangeOffset = new int[segCount];
for (int i = 0; i < segCount; i++)
{
idRangeOffset[i] = reader.ReadUInt16();
}
var glyphDictionary = new Dictionary <char, int>();
for (int i = 0; i < segCount - 1; i++)
{
if (idRangeOffset[i] == 0)
{
for (int c = startCode[i]; c <= endCode[i]; c++)
{
glyphDictionary.Add((char)c, idDelta[i] + c);
}
}
else
{
for (int c = startCode[i]; c <= endCode[i]; c++)
{
stream.Position = idRangeOffset[i] + 2 * (c - startCode[i]) + offset + i * 2;
glyphDictionary.Add((char)c, idDelta[i] + reader.ReadUInt16());
}
}
}
return(glyphDictionary);
}
public static string GetString(byte[] bytes) => bytes.TakeWhile(b => b != TerminationCharacter).Aggregate(string.Empty, (current, b) => current + EncodingTable.FirstOrDefault(et => et.Index == b).Character);
public DecodingTable(HuffmanTree tree)
{
var encodingTable = new EncodingTable(tree);
SetCodes(encodingTable);
}
/// <summary>
/// Initializes an encoder that encodes the <paramref name="inputStream" /> bytes with codes in the
/// <paramref name="encodingTable" /> to the <paramref name="outputStream" />.
/// </summary>
/// <param name="inputStream">The stream to read bytes from.</param>
/// <param name="outputStream">The stream to write encoded bytes to.</param>
/// <param name="encodingTable">The table containing Huffman codes for bytes.</param>
public Encoder(Stream inputStream, Stream outputStream, EncodingTable encodingTable)
{
InputStream = inputStream;
OutputStream = outputStream;
EncodingTable = encodingTable;
}
