public IEnumerable<FileEntry> ListFiles(Stream strm, Callbacks callbacks)
{
if (CRCCalculator == null) // should not happen, but who knows...
CRCCalculator = callbacks.GetCRCAlgorithm("CRC-32");
return GetDirectory(strm);
}
public void UnpackFiles(Stream strm, Callbacks callbacks)
{
if (CRCCalculator == null) // should not happen, but who knows...
CRCCalculator = callbacks.GetCRCAlgorithm("CRC-32");
List<FileEntry> files = GetDirectory(strm);
foreach (FileEntry ent in files)
{
FileHeader fh = ent.ObjectData["FileHeader"] as FileHeader;
byte[] buf = new byte[fh.CompressedSize];
strm.Seek(fh.FileDataStartOffset, SeekOrigin.Begin);
if (strm.Read(buf, 0, (int)fh.CompressedSize) != fh.CompressedSize)
throw new Exception("Read error");
switch (fh.Method)
{
case 0:
// uncompressed data
callbacks.WriteData(fh.Filename, buf);
break;
case 1:
case 2:
case 3:
// decode
break;
case 4:
break;
default:
throw new Exception("Unknown pack method");
}
}
}
public void UnpackFiles(Stream strm, Callbacks callbacks)
{
DirEntry[] files = GetDirectory(strm, false);
IDataTransformer trn = callbacks.TransformerRegistry.GetTransformer("zlib_dec");
string key;
// base offset = 4 bytes magic "VIS3" + 4 bytes #files + 3 bytes "HDR" marker + 16 bytes üer file + 3 bytes "END" marker
strm.Seek(8 + 3 + files.Length * 16 + 3, SeekOrigin.Begin);
for (int i = 0; i < files.Length; i++)
{
byte[] file = new byte[files[i].CompressedSize];
strm.Read(file, 0, file.Length);
key = "xxxxxxxx";
if ((files[i].Flags & 0x2) != 0)
{
// TODO: decrypt using our predefined key
}
if (files[i].CompressedSize != files[i].Size)
{
// compressed -> decompress
byte[] unc = new byte[files[i].Size];
int usize = files[i].Size;
trn.TransformData(file, unc, files[i].CompressedSize, ref usize);
file = unc;
}
if (files[i].Flags == 0x08)
{
// PNG file. Fix the scrambled dimensions
// find IHDR
int hdrpos = -1;
for (int j = 0; j < 32; j++)
{
if (Encoding.ASCII.GetString(file, j, 4) == "IHDR")
{
hdrpos = j - 4;
break;
}
}
if (hdrpos > 0)
{
// valid IHDR found. now try to fix it
int len = (int)(file[hdrpos] << 24) | (int)(file[hdrpos + 1] << 16) | (int)(file[hdrpos + 2]) << 8 | (int)(file[hdrpos + 3]);
byte[] hdr = new byte[len + 8];
byte[] fixed_hdr;
// copy to temporary array
Array.Copy(file, hdrpos + 4, hdr, 0, hdr.Length);
//.. and fix it by guessing
fixed_hdr = FixPngHdr(hdr, ref key, callbacks.GetCRCAlgorithm("CRC-32"));
if (fixed_hdr != null)
{
// could be fixed? great! then overwrite the old data with the fixed header
Array.Copy(fixed_hdr, 0, file, hdrpos + 4, fixed_hdr.Length);
}
}
}
callbacks.WriteData(String.Format("{0:x8}_{2}.{1}", i, GetExtension(files[i].Flags), key), file);
}
}
public bool IsSupported(Stream strm, Callbacks callbacks)
{
if (CRCCalculator == null)
CRCCalculator = callbacks.GetCRCAlgorithm("CRC-32");
return GetDirectory(strm) != null;
}
