protected virtual IFDEntry ParseIFDEntry(ushort tag, ushort type, uint count, long base_offset, uint offset)
{
if (tag == (ushort)ExifEntryTag.MakerNote && parse_makernote)
{
return(ParseMakernote(tag, type, count, base_offset, offset));
}
if (tag == (ushort)IFDEntryTag.SubIFDs)
{
var entries = new List <IFDStructure>();
uint[] data;
if (count >= 2)
{
if (base_offset + offset > file.Length)
{
file.MarkAsCorrupt("Length of SubIFD is too long");
return(null);
}
file.Seek(base_offset + offset, SeekOrigin.Begin);
data = ReadUIntArray(count);
}
else
{
data = new uint[]
{
offset
};
}
foreach (var sub_offset in data)
{
var sub_structure = new IFDStructure();
var sub_reader = CreateSubIFDReader(file, is_bigendian, sub_structure, base_offset, sub_offset, max_offset);
sub_reader.Read();
entries.Add(sub_structure);
}
return(new SubIFDArrayEntry(tag, entries));
}
IFDStructure ifd_structure = new IFDStructure();
IFDReader reader = CreateSubIFDReader(file, is_bigendian, ifd_structure, base_offset, offset, max_offset);
if (type == (ushort)IFDEntryType.IFD)
{
reader.Read();
return(new SubIFDEntry(tag, type, (uint)ifd_structure.Directories.Length, ifd_structure));
}
switch (tag)
{
case (ushort)
IFDEntryTag.ExifIFD:
case (ushort)
IFDEntryTag.InteroperabilityIFD:
case (ushort)
IFDEntryTag.GPSIFD:
reader.Read();
return(new SubIFDEntry(tag, (ushort)IFDEntryType.Long, 1, ifd_structure));
default:
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 ();
// 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)) {
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) {
// TODO: the max_offset value is not correct here. However, some nikon files have offsets to a sub-ifd
// (preview image) which are not stored with the other makernote data. Therfore, we keep the max_offset
// for now. (It is just an upper bound for some checks. So if it is too big, it doesn't matter)
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;
}
}
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);
}
}
/// <summary>
/// Reads the file with a specified read style.
/// </summary>
/// <param name="propertiesStyle">
/// A <see cref="ReadStyle" /> value specifying at what level
/// of accuracy to read the media properties, or <see
/// cref="ReadStyle.None" /> to ignore the properties.
/// </param>
private void Read (ReadStyle propertiesStyle)
{
Mode = AccessMode.Read;
try {
uint offset = ReadFirstIFDOffset ();
var ifd_tag = new IFDTag ();
var reader = new IFDReader (this, is_bigendian, ifd_tag.Structure, 0, offset, (uint) Length);
reader.Read ();
ImageTag.AddTag (ifd_tag);
// Find XMP data
var xmp_entry = ifd_tag.Structure.GetEntry (0, (ushort) IFDEntryTag.XMP) as ByteVectorIFDEntry;
if (xmp_entry != null) {
ImageTag.AddTag (new XmpTag (xmp_entry.Data.ToString ()));
}
if (propertiesStyle == ReadStyle.None)
return;
properties = ExtractProperties ();
} finally {
Mode = AccessMode.Closed;
}
}
/// <summary>
/// Reads an APP1 segment to find EXIF or XMP metadata.
/// </summary>
/// <param name="length">
/// The length of the segment that will be read.
/// </param>
private void ReadAPP1Segment (ushort length)
{
long position = Tell;
ByteVector data = null;
// for an Exif segment, the data block consists of 14 bytes of:
// * 6 bytes Exif identifier string
// * 2 bytes bigendian indication MM (or II)
// * 2 bytes Tiff magic number (42)
// * 4 bytes offset of the first IFD in this segment
//
// the last two points are alreay encoded according to
// big- or littleendian
int exif_header_length = 14;
// could be an Exif segment
if ((ImageTag.TagTypes & TagLib.TagTypes.TiffIFD) == 0x00 && length >= exif_header_length) {
data = ReadBlock (exif_header_length);
if (data.Count == exif_header_length
&& data.Mid (0, 6).ToString ().Equals (EXIF_IDENTIFIER)) {
bool is_bigendian = data.Mid (6, 2).ToString ().Equals ("MM");
ushort magic = data.Mid (8, 2).ToUShort (is_bigendian);
if (magic != 42)
throw new Exception (String.Format ("Invalid TIFF magic: {0}", magic));
uint ifd_offset = data.Mid (10, 4).ToUInt (is_bigendian);
var exif = new IFDTag ();
var reader = new IFDReader (this, is_bigendian, exif.Structure, position + 6, ifd_offset, (uint) (length - 6));
reader.Read ();
ImageTag.AddTag (exif);
AddMetadataBlock (position - 4, length + 4);
return;
}
}
int xmp_header_length = XmpTag.XAP_NS.Length + 1;
// could be an Xmp segment
if ((ImageTag.TagTypes & TagLib.TagTypes.XMP) == 0x00 && length >= xmp_header_length) {
// if already data is read for determining the Exif segment,
// just read the remaining bytes.
// NOTE: that (exif_header_length < xmp_header_length) holds
if (data == null)
data = ReadBlock (xmp_header_length);
else
data.Add (ReadBlock (xmp_header_length - exif_header_length));
if (data.ToString ().Equals (XmpTag.XAP_NS + "\0")) {
ByteVector xmp_data = ReadBlock (length - xmp_header_length);
ImageTag.AddTag (new XmpTag (xmp_data.ToString (), this));
AddMetadataBlock (position - 4, length + 4);
}
}
}
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);
}
}