public EntropyResults CalculateMediaEntropy(bool duplicatedSectors)
{
var entropy = new EntropyResults
{
Entropy = 0
};
ulong[] entTable = new ulong[256];
ulong diskSize = 0;
List <string> uniqueSectors = new List <string>();
entropy.Sectors = inputFormat.Info.Sectors;
AaruConsole.WriteLine("Sectors {0}", entropy.Sectors);
InitProgressEvent?.Invoke();
for (ulong i = 0; i < entropy.Sectors; i++)
{
UpdateProgressEvent?.Invoke($"Entropying sector {i + 1}", (long)(i + 1), (long)entropy.Sectors);
byte[] sector = inputFormat.ReadSector(i);
if (duplicatedSectors)
{
string sectorHash = Sha1Context.Data(sector, out _);
if (!uniqueSectors.Contains(sectorHash))
{
uniqueSectors.Add(sectorHash);
}
}
foreach (byte b in sector)
{
entTable[b]++;
}
diskSize += (ulong)sector.LongLength;
}
EndProgressEvent?.Invoke();
entropy.Entropy += entTable.Select(l => (double)l / (double)diskSize).
Select(frequency => - (frequency * Math.Log(frequency, 2))).Sum();
if (duplicatedSectors)
{
entropy.UniqueSectors = uniqueSectors.Count;
}
return(entropy);
}
public void EndProgress()
{
EndProgressEvent?.Invoke();
}
public EntropyResults[] CalculateTracksEntropy(bool duplicatedSectors)
{
List <EntropyResults> entropyResultses = new List <EntropyResults>();
if (!(inputFormat is IOpticalMediaImage opticalMediaImage))
{
DicConsole.ErrorWriteLine("The selected image does not support tracks.");
return(entropyResultses.ToArray());
}
try
{
List <Track> inputTracks = opticalMediaImage.Tracks;
InitProgressEvent?.Invoke();
foreach (Track currentTrack in inputTracks)
{
EntropyResults trackEntropy = new EntropyResults {
Track = currentTrack.TrackSequence, Entropy = 0
};
UpdateProgressEvent
?.Invoke($"Entropying track {currentTrack.TrackSequence} of {inputTracks.Max(t => t.TrackSequence)}",
currentTrack.TrackSequence, inputTracks.Max(t => t.TrackSequence));
ulong[] entTable = new ulong[256];
ulong trackSize = 0;
List <string> uniqueSectorsPerTrack = new List <string>();
trackEntropy.Sectors = currentTrack.TrackEndSector - currentTrack.TrackStartSector + 1;
DicConsole.VerboseWriteLine("Track {0} has {1} sectors", currentTrack.TrackSequence,
trackEntropy.Sectors);
InitProgress2Event?.Invoke();
for (ulong i = currentTrack.TrackStartSector; i <= currentTrack.TrackEndSector; i++)
{
UpdateProgress2Event
?.Invoke($"Entropying sector {i + 1} of track {currentTrack.TrackSequence}",
(long)(currentTrack.TrackEndSector - (i + 1)),
(long)trackEntropy.Sectors);
byte[] sector = opticalMediaImage.ReadSector(i, currentTrack.TrackSequence);
if (duplicatedSectors)
{
string sectorHash = Sha1Context.Data(sector, out _);
if (!uniqueSectorsPerTrack.Contains(sectorHash))
{
uniqueSectorsPerTrack.Add(sectorHash);
}
}
foreach (byte b in sector)
{
entTable[b]++;
}
trackSize += (ulong)sector.LongLength;
}
EndProgress2Event?.Invoke();
trackEntropy.Entropy += entTable.Select(l => (double)l / (double)trackSize)
.Select(frequency => - (frequency * Math.Log(frequency, 2))).Sum();
if (duplicatedSectors)
{
trackEntropy.UniqueSectors = uniqueSectorsPerTrack.Count;
}
entropyResultses.Add(trackEntropy);
}
EndProgressEvent?.Invoke();
}
catch (Exception ex)
{
if (debug)
{
DicConsole.DebugWriteLine("Could not get tracks because {0}", ex.Message);
}
else
{
DicConsole.ErrorWriteLine("Unable to get separate tracks, not calculating their entropy");
}
}
return(entropyResultses.ToArray());
}