private static IEnumerable <Ddr573DirectoryEntry> DecodeInternal(Ddr573Image image)
{
if (!image.Modules.Any())
{
throw new RhythmCodexException("There must be at least one module in the image.");
}
if (!image.Modules.ContainsKey(0))
{
throw new RhythmCodexException("A module with index 0 must be present in the image.");
}
var reader = new MemoryReader(image.Modules[0]);
Ddr573DirectoryEntry GetDdrFile()
{
var file = new Ddr573DirectoryEntry
{
Id = reader.ReadInt32(),
Offset = reader.ReadInt16() * 0x800,
Module = reader.ReadInt16(),
CompressionType = reader.ReadByte(),
EncryptionType = reader.ReadByte(),
Reserved1 = reader.ReadByte(),
Reserved2 = reader.ReadByte(),
Length = reader.ReadInt32()
};
return(file.Id == 0 ? null : file);
}
Ddr573DirectoryEntry GetDsFile()
{
throw new RhythmCodexException("Retrieving Dancing Stage directory entries is not yet supported.");
}
Func <Ddr573DirectoryEntry> GetDirectoryReader()
{
reader.Position = 0x24;
if (reader.ReadInt32() == PsxIdString)
{
reader.Position = 0xFE4000;
if (reader.ReadInt32() > 0)
{
reader.Position = 0xFE4000;
return(GetDdrFile);
}
reader.Position = 0x100000;
if (reader.ReadInt32() > 0)
{
reader.Position = 0x100000;
return(GetDdrFile);
}
reader.Position = 0x64F000;
if (reader.ReadInt32() > 0)
{
reader.Position = 0x64F000;
return(GetDsFile);
}
}
else
{
reader.Position = 0x824;
if (reader.ReadInt32() == PsxIdString)
{
reader.Position = 0x100800;
if (reader.ReadInt32() > 0)
{
reader.Position = 0x100800;
return(GetDsFile);
}
}
}
throw new RhythmCodexException("The directory is not recognized.");
}
var read = GetDirectoryReader();
while (true)
{
var entry = read();
if (entry == null)
{
yield break;
}
yield return(entry);
}
}
private IEnumerable <Ddr573File> DecodeInternal(Ddr573Image image, string dbKey)
{
if (!image.Modules.Any())
{
throw new RhythmCodexException("There must be at least one module in the image.");
}
if (!image.Modules.ContainsKey(0))
{
throw new RhythmCodexException("A module with index 0 must be present in the image.");
}
var readers = image.Modules
.ToDictionary(kv => kv.Key, kv => new BinaryReader(new ReadOnlyMemoryStream(kv.Value)));
try
{
foreach (var entry in _ddr573ImageDirectoryDecoder.Decode(image))
{
if (!readers.ContainsKey(entry.Module))
{
throw new RhythmCodexException($"Module {entry.Module} was requested, but not found.");
}
var canDecompress = true;
var moduleReader = readers[entry.Module];
moduleReader.BaseStream.Position = entry.Offset;
Memory <byte> data = moduleReader.ReadBytes(entry.Length);
switch (entry.EncryptionType)
{
case 1:
{
if (dbKey != null)
{
data = _ddr573DatabaseDecrypter.Decrypt(data.Span, _ddr573DatabaseDecrypter.ConvertKey(dbKey));
}
else
{
canDecompress = false;
}
break;
}
}
if (canDecompress)
{
switch (entry.CompressionType)
{
case 1:
{
using (var compressedStream = new ReadOnlyMemoryStream(data))
{
try
{
data = _bemaniLzDecoder.Decode(compressedStream);
}
catch (Exception)
{
_logger.Warning($"Entry Id={entry.Id:X8} Module={entry.Module:X4} Offset={entry.Offset:X7} could not be decompressed. It will be extracted as-is.");
}
}
break;
}
}
}
yield return(new Ddr573File
{
Data = data,
Id = entry.Id,
Module = entry.Module,
Offset = entry.Offset,
EncryptionType = entry.EncryptionType,
Reserved1 = entry.Reserved1,
Reserved2 = entry.Reserved2
});
}
}
finally
{
foreach (var reader in readers)
{
reader.Value?.Dispose();
}
}
}
public IList <Ddr573DirectoryEntry> Decode(Ddr573Image image)
{
return(DecodeInternal(image).ToList());
}
public IList <Ddr573File> Decode(Ddr573Image image, string dbKey)
{
return(DecodeInternal(image, dbKey).ToList());
}
