public static byte[] DecodeData(UmdDiscSector sector, UmdDisc disc, UmdDisc parentDisc)
{
return(sector.Encoding switch
{
UmdEncoding.None => sector.Data ?? throw new InvalidOperationException("No data in sector"),
UmdEncoding.InternalLink => DecodeInternalLink(sector, disc) ?? throw new InvalidOperationException("Internally linked sector has no data."),
UmdEncoding.ExternalLink => DecodeExternalLink(sector, parentDisc) ?? throw new InvalidOperationException("Internally linked sector has no data."),
_ => throw new InvalidOperationException("Unsupported encoding")
});
public static UmdDisc?ReadFromIso(string filename, bool withData = false)
{
const ushort sectorSize = 2048;
try
{
var result = new UmdDisc();
var fileInfo = new FileInfo(filename);
if (fileInfo.Length % sectorSize != 0)
{
return(null);
}
var buffer = new byte[sectorSize];
using var stream = new FileStream(filename, FileMode.Open, FileAccess.Read);
using var reader = new BinaryReader(stream);
uint sectorCount = (uint)(fileInfo.Length / sectorSize);
for (uint i = 0; i < sectorCount; i++)
{
reader.Read(buffer, 0, sectorSize);
var sector = new UmdDiscSector
{
Id = i,
Crc32 = Crc32Algorithm.Compute(buffer, 0, sectorSize),
Length = sectorSize,
StartPostiion = (uint)(i * sectorSize)
};
if (withData)
{
sector.Data = buffer;
buffer = new byte[sectorSize];
}
result.Sectors.Add(sector);
}
return(result);
}
catch
{
return(null);
}
}
private static byte[]? DecodeInternalLink(UmdDiscSector sector, UmdDisc disc)
{
var sectorId = BitConverter.ToInt32(sector.Data);
return(disc.Sectors[sectorId].Data);
}
