internal static byte[] Compress(byte[] bytesToCompress, CompressionFlavor flavor)
{
if (bytesToCompress == null)
{
throw new InvalidDataException("Cannot compress null array");
}
if (flavor == CompressionFlavor.StoreUncompressed)
{
throw new InvalidOperationException("Chunk format cannot be used for uncompressed data");
}
MemoryStream output = new MemoryStream(bytesToCompress.Length);
BinaryWriter writer = new BinaryWriter(output);
writer.Write(Chunk.Header);
writer.Write(Chunk.DefaultVersion);
writer.Write((byte)CompressionMethod.ZLib);
writer.Write(NoObfuscation);
using (MemoryStream compressedStream = new MemoryStream(bytesToCompress.Length))
{
compressedStream.WriteByte(0x78); //ZLib header first byte
compressedStream.WriteByte(0xDA); //ZLib header second byte
switch (flavor)
{
case CompressionFlavor.ZLibDeflate:
using (DeflateStream deflateStream = new DeflateStream(compressedStream, CompressionLevel.Optimal, true))
deflateStream.Write(bytesToCompress, 0, bytesToCompress.Length);
break;
case CompressionFlavor.i5ZopfliDeflate:
case CompressionFlavor.i10ZopfliDeflate:
case CompressionFlavor.i15ZopfliDeflate:
if (bytesToCompress.Length < Strategy.ZopfliBreakEven) //Skip Zopfli if file is small
{
goto case CompressionFlavor.ZLibDeflate;
}
ZopfliDeflater zstream = new ZopfliDeflater(compressedStream);
zstream.NumberOfIterations = (int)flavor;
zstream.MasterBlockSize = 0;
zstream.Deflate(bytesToCompress, true);
break;
default:
throw new InvalidOperationException("Unknow compression flavor");
}
var compressedDataArray = compressedStream.ToArray(); //Change to stream
int checksum = ComputeChecksum(compressedDataArray); //Change to stream
writer.Write(compressedDataArray.Length);
writer.Write(bytesToCompress.Length);
writer.Write(checksum);
writer.Write(compressedDataArray);
}
return(output.ToArray());
}
internal void CompressIDAT(bool useZopfli)
{
byte[] data = idat.GetChunkData();
using (MemoryStream inputStream = new MemoryStream(data, 2, data.Length - 6))
{
using (MemoryStream tempStream = new MemoryStream())
{
using (DeflateStream inflateStream = new DeflateStream(inputStream, CompressionMode.Decompress, true))
{
inflateStream.CopyTo(tempStream);
}
//ZOutputStream zOutputStream1 = new ZOutputStream(tempStream);
//CopyStream(inputStream, zOutputStream1);
//zOutputStream1.Flush();
tempStream.Position = 0;
using (MemoryStream outputStream = new MemoryStream())
{
if (useZopfli)
{
outputStream.Write(zlibBestCompressionFlag, 0, 2);
byte[] dataRaw = new byte[tempStream.Length];
tempStream.Read(dataRaw, 0, dataRaw.Length);
ZopfliDeflater zopfliDeflater = new ZopfliDeflater(outputStream);
zopfliDeflater.Deflate(dataRaw, false);
}
else
{
ZOutputStream zOutputStream = new ZOutputStream(outputStream, zlibConst.Z_NO_COMPRESSION);
CopyStream(tempStream, zOutputStream);
zOutputStream.Flush();
//outputStream.Write(zlibNoCompressionFlag, 0, 2);
//using (DeflateStream deflateStream = new DeflateStream(outputStream, CompressionLevel.NoCompression, true))
//{
// tempStream.CopyTo(deflateStream, 34572);
//}
}
byte[] dataNew = new byte[outputStream.Length];
outputStream.Position = 0;
outputStream.Read(dataNew, 0, dataNew.Length);
for (int j = 0; j < dataNew.Length; j++)
{
if (data[j] != dataNew[j])
{
Console.WriteLine("{0:D}", j);
}
}
idat.SetChunkData(dataNew);
idat.Refresh();
}
}
}
}