IFDEntry ParseMakernote(ushort tag, ushort type, uint count, long baseOffset, uint offset)
{
long makernote_offset = baseOffset + offset;
var ifd_structure = new IFDStructure();
// This is the minimum size a makernote should have
// The shortest header is PENTAX_HEADER (4)
// + IFD entry count (2)
// + at least one IFD etry (12)
// + next IFD pointer (4)
// = 22 ....
// we use this number to read a header which is big used
// to identify the makernote types
int header_size = 18;
long length = 0;
try {
length = file.Length;
} catch (Exception) {
// Use a safety-value of 4 gigabyte.
length = 1073741824L * 4;
}
if (makernote_offset > length)
{
file.MarkAsCorrupt("offset to makernote is beyond file size");
return(null);
}
if (makernote_offset + header_size > length)
{
file.MarkAsCorrupt("data is to short to contain a maker note ifd");
return(null);
}
// read header
file.Seek(makernote_offset, SeekOrigin.Begin);
ByteVector header = file.ReadBlock(header_size);
if (header.StartsWith(PANASONIC_HEADER))
{
var reader = new IFDReader(file, is_bigendian, ifd_structure, baseOffset, offset + 12, max_offset);
reader.ReadIFD(baseOffset, offset + 12, max_offset);
return(new MakernoteIFDEntry(tag, ifd_structure, MakernoteType.Panasonic, PANASONIC_HEADER, 12, true, null));
}
if (header.StartsWith(PENTAX_HEADER))
{
var reader = new IFDReader(file, is_bigendian, ifd_structure, baseOffset, offset + 6, max_offset);
reader.ReadIFD(baseOffset, offset + 6, max_offset);
return(new MakernoteIFDEntry(tag, ifd_structure, MakernoteType.Pentax, header.Mid(0, 6), 6, true, null));
}
if (header.StartsWith(OLYMPUS1_HEADER))
{
var reader = new IFDReader(file, is_bigendian, ifd_structure, baseOffset, offset + 8, max_offset);
reader.Read();
return(new MakernoteIFDEntry(tag, ifd_structure, MakernoteType.Olympus1, header.Mid(0, 8), 8, true, null));
}
if (header.StartsWith(OLYMPUS2_HEADER))
{
var reader = new IFDReader(file, is_bigendian, ifd_structure, makernote_offset, 12, count);
reader.Read();
return(new MakernoteIFDEntry(tag, ifd_structure, MakernoteType.Olympus2, header.Mid(0, 12), 12, false, null));
}
if (header.StartsWith(SONY_HEADER))
{
var reader = new IFDReader(file, is_bigendian, ifd_structure, baseOffset, offset + 12, max_offset);
reader.ReadIFD(baseOffset, offset + 12, max_offset);
return(new MakernoteIFDEntry(tag, ifd_structure, MakernoteType.Sony, SONY_HEADER, 12, true, null));
}
if (header.StartsWith(NIKON_HEADER))
{
ByteVector endian_bytes = header.Mid(10, 2);
if (endian_bytes.ToString() == "II" || endian_bytes.ToString() == "MM")
{
bool makernote_endian = endian_bytes.ToString().Equals("MM");
ushort magic = header.Mid(12, 2).ToUShort(is_bigendian);
if (magic == 42)
{
var reader = new Nikon3MakernoteReader(file, makernote_endian, ifd_structure, makernote_offset + 10, 8, max_offset - offset - 10);
reader.Read();
return(new MakernoteIFDEntry(tag, ifd_structure, MakernoteType.Nikon3, header.Mid(0, 18), 8, false, makernote_endian));
}
}
}
if (header.StartsWith(LEICA_HEADER))
{
var reader = new IFDReader(file, is_bigendian, ifd_structure, makernote_offset, 8, count);
reader.Read();
return(new MakernoteIFDEntry(tag, ifd_structure, MakernoteType.Leica, header.Mid(0, 8), 10, false, null));
}
try {
var reader = new IFDReader(file, is_bigendian, ifd_structure, baseOffset, offset, max_offset);
reader.Read();
return(new MakernoteIFDEntry(tag, ifd_structure, MakernoteType.Canon));
} catch {
return(null);
}
}
private IFDEntry ParseMakernote(ushort tag, ushort type, uint count, long base_offset, uint offset)
{
long makernote_offset = base_offset + offset;
IFDStructure ifd_structure = new IFDStructure();
int header_size = 18;
long length = 0;
try
{
length = file.Length;
}
catch (Exception)
{
length = 1073741824L * 4;
}
if (makernote_offset > length)
{
file.MarkAsCorrupt("offset to makernote is beyond file size");
return(null);
}
if (makernote_offset + header_size > length)
{
file.MarkAsCorrupt("data is to short to contain a maker note ifd");
return(null);
}
file.Seek(makernote_offset, SeekOrigin.Begin);
ByteVector header = file.ReadBlock(header_size);
if (header.StartsWith(PANASONIC_HEADER))
{
IFDReader reader = new IFDReader(file, is_bigendian, ifd_structure, base_offset, offset + 12, max_offset);
reader.ReadIFD(base_offset, offset + 12, max_offset);
return(new MakernoteIFDEntry(tag, ifd_structure, MakernoteType.Panasonic, PANASONIC_HEADER, 12, true, null));
}
if (header.StartsWith(PENTAX_HEADER))
{
IFDReader reader = new IFDReader(file, is_bigendian, ifd_structure, base_offset, offset + 6, max_offset);
reader.ReadIFD(base_offset, offset + 6, max_offset);
return(new MakernoteIFDEntry(tag, ifd_structure, MakernoteType.Pentax, header.Mid(0, 6), 6, true, null));
}
if (header.StartsWith(OLYMPUS1_HEADER))
{
IFDReader reader = new IFDReader(file, is_bigendian, ifd_structure, base_offset, offset + 8, max_offset);
reader.Read();
return(new MakernoteIFDEntry(tag, ifd_structure, MakernoteType.Olympus1, header.Mid(0, 8), 8, true, null));
}
if (header.StartsWith(OLYMPUS2_HEADER))
{
IFDReader reader = new IFDReader(file, is_bigendian, ifd_structure, makernote_offset, 12, count);
reader.Read();
return(new MakernoteIFDEntry(tag, ifd_structure, MakernoteType.Olympus2, header.Mid(0, 12), 12, false, null));
}
if (header.StartsWith(SONY_HEADER))
{
IFDReader reader = new IFDReader(file, is_bigendian, ifd_structure, base_offset, offset + 12, max_offset);
reader.ReadIFD(base_offset, offset + 12, max_offset);
return(new MakernoteIFDEntry(tag, ifd_structure, MakernoteType.Sony, SONY_HEADER, 12, true, null));
}
if (header.StartsWith(NIKON_HEADER))
{
ByteVector endian_bytes = header.Mid(10, 2);
if (endian_bytes.ToString() == "II" || endian_bytes.ToString() == "MM")
{
bool makernote_endian = endian_bytes.ToString().Equals("MM");
ushort magic = header.Mid(12, 2).ToUShort(is_bigendian);
if (magic == 42)
{
var reader = new Nikon3MakernoteReader(file, makernote_endian, ifd_structure, makernote_offset + 10, 8, max_offset - offset - 10);
reader.Read();
return(new MakernoteIFDEntry(tag, ifd_structure, MakernoteType.Nikon3, header.Mid(0, 18), 8, false, makernote_endian));
}
}
}
if (header.StartsWith(LEICA_HEADER))
{
IFDReader reader = new IFDReader(file, is_bigendian, ifd_structure, makernote_offset, 8, count);
reader.Read();
return(new MakernoteIFDEntry(tag, ifd_structure, MakernoteType.Leica, header.Mid(0, 8), 10, false, null));
}
try
{
IFDReader reader = new IFDReader(file, is_bigendian, ifd_structure, base_offset, offset, max_offset);
reader.Read();
return(new MakernoteIFDEntry(tag, ifd_structure, MakernoteType.Canon));
}
catch
{
return(null);
}
}