public void UnitE_AsciizToString()
{
var buf = new byte[] { 0x30, 0x31, 0x42, 0x43, 0x44, 0, 0x46, 0x47 };
var result = ConvertTo.FromAsciizToString(buf, 2);
Assert.AreEqual(result.GetType(), typeof(string));
Assert.AreEqual("BCD", result);
}
public Model(Stream stream, string path)
{
base._data = Data = new JpegFormat(this, stream, path);
// Arbitrary choice of 50MB cutoff.
if (Data.FileSize > 50000000)
{
IssueModel.Add("File insanely huge", Severity.Fatal);
return;
}
byte[] buf = new byte[(int)Data.FileSize];
stream.Position = 0;
int got = stream.Read(buf, 0, (int)Data.FileSize);
if (got != Data.FileSize)
{
IssueModel.Add("Read error", Severity.Fatal);
return;
}
for (int len = 0, pos = 2; ; pos = pos + len + 2)
{
if (pos > Data.FileSize - 4)
{
IssueModel.Add("File truncated", Severity.Fatal);
return;
}
if (buf[pos] != 0xFF)
{
IssueModel.Add("Missing marker.", Severity.Fatal);
return;
}
if (buf[pos + 1] == 0xD9)
{
IssueModel.Add("Unexpected EOI marker", Severity.Fatal);
return;
}
// Detect SOS (Start of Stream) marker.
if (buf[pos + 1] == 0xDA)
{
Data.sosPos = pos;
break;
}
len = (buf[pos + 2] << 8) + buf[pos + 3];
if (len < 2)
{
IssueModel.Add("Invalid segment length '" + len + "'.", Severity.Fatal);
return;
}
if (pos + len + 2 >= Data.FileSize)
{
IssueModel.Add("File truncated.", Severity.Fatal);
return;
}
if (len == 2)
{
IssueModel.Add("Contains empty segment.", Severity.Trivia);
}
++Data.SegmentCount;
// Detect application marker:
if (buf[pos + 1] >= 0xE0 && buf[pos + 1] <= 0xEF)
{
string appName = ConvertTo.FromAsciizToString(buf, pos + 4);
Data.appNames.Add(appName);
if (buf[pos + 1] == 0xE0)
{
if (buf[pos + 4] != 'J' || buf[pos + 5] != 'F' || buf[pos + 6] != 'I' || buf[pos + 7] != 'F' || buf[pos + 8] != 0)
{
continue;
}
if ((Data.Apps & JpegApps.Jfif) != 0)
{
IssueModel.Add("Contains ghost JFIF segment.", Severity.Advisory);
continue;
}
if (len < 13)
{
IssueModel.Add("JFIF segment too small.", Severity.Fatal);
return;
}
Data.Apps |= JpegApps.Jfif;
Data.VersionMajor = buf[pos + 0x09];
Data.VersionMinor = buf[pos + 0x0A];
Data.Units = (JpegUnits)buf[pos + 0x0B];
Data.DensityX = (buf[pos + 0x0C] << 8) + buf[pos + 0x0D];
Data.DensityY = (buf[pos + 0x0E] << 8) + buf[pos + 0x0F];
Data.ThumbXLen = buf[pos + 0x10];
Data.ThumbYLen = buf[pos + 0x11];
}
else if (buf[pos + 1] == 0xE1)
{
if (buf[pos + 4] == 'E' && buf[pos + 5] == 'x' && buf[pos + 6] == 'i' && buf[pos + 7] == 'f' && buf[pos + 8] == 0)
{
if ((Data.Apps & JpegApps.Exif) != 0)
{
IssueModel.Add("Contains ghost Exif segment", Severity.Trivia);
continue;
}
Data.Apps |= JpegApps.Exif;
// Additional Exif parsing goes here...
}
}
}
}
// Detect EOI (end of image) marker: FFD9
for (int pos = (int)Data.sosPos; pos < Data.FileSize - 1; ++pos)
{
if (buf[pos] == 0xFF && buf[pos + 1] == 0xD9)
{
Data.ValidSize = pos + 2;
Data.eoiPos = pos;
break;
}
}
CalcMark();
GetDiagnostics();
}
