private static string Calculate(DriveInfo drive, IEnumerable <string> fileNames)
{
List <FileInfo> files = fileNames.Select(fileName => new FileInfo(fileName)).ToList();
files.Sort(CompareFiles);
List <byte[]> hashes = new List <byte[]>();
//Step 2:
//The file headers from each file are computed in the CRC.
foreach (FileInfo file in files)
{
AddFileMetaHash(file, hashes);
}
//Step 3:
//The data from the VMGI file ("VIDEO_TS\VIDEO_TS.IFO") is computed in the CRC.
//If present, the first 65,536 bytes of "VIDEO_TS.IFO are read and added to the CRC (if smaller then the entire file is added)
AddFileContentHash(drive, "VIDEO_TS.IFO", hashes);
//Note: On page 19 the patents talks about "the first VTSI file ('VIDEO_TS\VTS_xx_0.IFO')"
// but on page 20 it explicitly specifies "VTS_01_0.IFO".
//Step 4:
//The data from the first VTSI file ("VIDEO_TS\VTS_xx_0.IFO") is computed in the CRC.
string vtsFileName = GetVtsFileName(drive);
//If present, the first 65,536 bytes of "VTS_01_0.IFO" are read and added to the CRC (if smaller then the entire file is added)
AddFileContentHash(drive, vtsFileName, hashes);
byte[] hashBytes = hashes.SelectMany(bytes => bytes).ToArray();
ulong hash = Crc64.Calculate(hashBytes);
string result = hash.ToString("X").PadLeft(16, '0');
return(result);
}