public override bool CustomProcessTag(int tagOffset, ICollection <int> processedIfdOffsets, IndexedReader reader, int tagId, int byteCount)
{
// Some 0x0000 tags have a 0 byteCount. Determine whether it's bad.
if (tagId == 0)
{
if (CurrentDirectory.ContainsTag(tagId))
{
// Let it go through for now. Some directories handle it, some don't.
return(false);
}
// Skip over 0x0000 tags that don't have any associated bytes. No idea what it contains in this case, if anything.
if (byteCount == 0)
{
return(true);
}
}
// Custom processing for the Makernote tag
if (tagId == ExifDirectoryBase.TagMakernote && CurrentDirectory is ExifSubIfdDirectory)
{
return(ProcessMakernote(tagOffset, processedIfdOffsets, reader));
}
// Custom processing for embedded IPTC data
if (tagId == ExifDirectoryBase.TagIptcNaa && CurrentDirectory is ExifIfd0Directory)
{
// NOTE Adobe sets type 4 for IPTC instead of 7
if (reader.GetSByte(tagOffset) == 0x1c)
{
var iptcBytes = reader.GetBytes(tagOffset, byteCount);
var iptcDirectory = new IptcReader().Extract(new SequentialByteArrayReader(iptcBytes), iptcBytes.Length);
iptcDirectory.Parent = CurrentDirectory;
Directories.Add(iptcDirectory);
return(true);
}
return(false);
}
// Custom processing for embedded XMP data
if (tagId == ExifDirectoryBase.TagApplicationNotes && CurrentDirectory is ExifIfd0Directory)
{
var xmpDirectory = new XmpReader().Extract(reader.GetNullTerminatedBytes(tagOffset, byteCount));
xmpDirectory.Parent = CurrentDirectory;
Directories.Add(xmpDirectory);
return(true);
}
if (HandlePrintIM(CurrentDirectory, tagId))
{
var dirPrintIm = new PrintIMDirectory();
dirPrintIm.Parent = CurrentDirectory;
Directories.Add(dirPrintIm);
ProcessPrintIM(dirPrintIm, tagOffset, reader, byteCount);
return(true);
}
// Note: these also appear in TryEnterSubIfd because some are IFD pointers while others begin immediately
// for the same directories
if (CurrentDirectory is OlympusMakernoteDirectory)
{
switch (tagId)
{
case OlympusMakernoteDirectory.TagEquipment:
PushDirectory(new OlympusEquipmentMakernoteDirectory());
TiffReader.ProcessIfd(this, reader, processedIfdOffsets, tagOffset);
return(true);
case OlympusMakernoteDirectory.TagCameraSettings:
PushDirectory(new OlympusCameraSettingsMakernoteDirectory());
TiffReader.ProcessIfd(this, reader, processedIfdOffsets, tagOffset);
return(true);
case OlympusMakernoteDirectory.TagRawDevelopment:
PushDirectory(new OlympusRawDevelopmentMakernoteDirectory());
TiffReader.ProcessIfd(this, reader, processedIfdOffsets, tagOffset);
return(true);
case OlympusMakernoteDirectory.TagRawDevelopment2:
PushDirectory(new OlympusRawDevelopment2MakernoteDirectory());
TiffReader.ProcessIfd(this, reader, processedIfdOffsets, tagOffset);
return(true);
case OlympusMakernoteDirectory.TagImageProcessing:
PushDirectory(new OlympusImageProcessingMakernoteDirectory());
TiffReader.ProcessIfd(this, reader, processedIfdOffsets, tagOffset);
return(true);
case OlympusMakernoteDirectory.TagFocusInfo:
PushDirectory(new OlympusFocusInfoMakernoteDirectory());
TiffReader.ProcessIfd(this, reader, processedIfdOffsets, tagOffset);
return(true);
case OlympusMakernoteDirectory.TagRawInfo:
PushDirectory(new OlympusRawInfoMakernoteDirectory());
TiffReader.ProcessIfd(this, reader, processedIfdOffsets, tagOffset);
return(true);
case OlympusMakernoteDirectory.TagMainInfo:
PushDirectory(new OlympusMakernoteDirectory());
TiffReader.ProcessIfd(this, reader, processedIfdOffsets, tagOffset);
return(true);
}
}
if (CurrentDirectory is PanasonicRawIfd0Directory)
{
// these contain binary data with specific offsets, and can't be processed as regular ifd's.
// The binary data is broken into 'fake' tags and there is a pattern.
switch (tagId)
{
case PanasonicRawIfd0Directory.TagWbInfo:
var dirWbInfo = new PanasonicRawWbInfoDirectory();
dirWbInfo.Parent = CurrentDirectory;
Directories.Add(dirWbInfo);
ProcessBinary(dirWbInfo, tagOffset, reader, byteCount, false, 2);
return(true);
case PanasonicRawIfd0Directory.TagWbInfo2:
var dirWbInfo2 = new PanasonicRawWbInfo2Directory();
dirWbInfo2.Parent = CurrentDirectory;
Directories.Add(dirWbInfo2);
ProcessBinary(dirWbInfo2, tagOffset, reader, byteCount, false, 3);
return(true);
case PanasonicRawIfd0Directory.TagDistortionInfo:
var dirDistort = new PanasonicRawDistortionDirectory();
dirDistort.Parent = CurrentDirectory;
Directories.Add(dirDistort);
ProcessBinary(dirDistort, tagOffset, reader, byteCount);
return(true);
}
}
// Panasonic RAW sometimes contains an embedded version of the data as a JPG file.
if (tagId == PanasonicRawIfd0Directory.TagJpgFromRaw && CurrentDirectory is PanasonicRawIfd0Directory)
{
var jpegrawbytes = reader.GetBytes(tagOffset, byteCount);
// Extract information from embedded image since it is metadata-rich
var jpegmem = new MemoryStream(jpegrawbytes);
var jpegDirectory = Jpeg.JpegMetadataReader.ReadMetadata(jpegmem);
foreach (var dir in jpegDirectory)
{
dir.Parent = CurrentDirectory;
Directories.Add(dir);
}
return(true);
}
return(false);
}
