public XmpDirectory Extract([NotNull] byte[] xmpBytes, int offset, int length)
{
if (offset < 0)
{
throw new ArgumentOutOfRangeException(nameof(offset), "Must be zero or greater.");
}
if (length < 0)
{
throw new ArgumentOutOfRangeException(nameof(length), "Must be zero or greater.");
}
if (xmpBytes.Length < offset + length)
{
throw new ArgumentException("Extends beyond length of byte array.", nameof(length));
}
// Trim any trailing null bytes
// https://github.com/drewnoakes/metadata-extractor-dotnet/issues/154
while (xmpBytes[offset + length - 1] == 0)
{
length--;
}
var directory = new XmpDirectory();
try
{
// Limit photoshop:DocumentAncestors node as it can reach over 100000 items and make parsing extremely slow.
// This is not a typical value but it may happen https://forums.adobe.com/thread/2081839
var parseOptions = new ParseOptions();
parseOptions.SetXMPNodesToLimit(new Dictionary <string, int>()
{
{ "photoshop:DocumentAncestors", 1000 }
});
var xmpMeta = XmpMetaFactory.ParseFromBuffer(xmpBytes, offset, length, parseOptions);
directory.SetXmpMeta(xmpMeta);
}
catch (XmpException e)
{
directory.AddError("Error processing XMP data: " + e.Message);
}
return(directory);
}