/// <summary>
/// Performs the IPTC data extraction, adding found values to the specified instance of
/// <see cref="Com.Drew.Metadata.Metadata"/>
/// .
/// </summary>
public virtual void Extract(SequentialReader reader, Com.Drew.Metadata.Metadata metadata, long length)
{
IptcDirectory directory = metadata.GetOrCreateDirectory <IptcDirectory>();
int offset = 0;
// for each tag
while (offset < length)
{
// identifies start of a tag
short startByte;
try
{
startByte = reader.GetUInt8();
offset++;
}
catch (IOException)
{
directory.AddError("Unable to read starting byte of IPTC tag");
return;
}
if (startByte != unchecked ((int)(0x1c)))
{
directory.AddError("Invalid start to IPTC tag");
return;
}
// we need at least five bytes left to read a tag
if (offset + 5 >= length)
{
directory.AddError("Too few bytes remain for a valid IPTC tag");
return;
}
int directoryType;
int tagType;
int tagByteCount;
try
{
directoryType = reader.GetUInt8();
tagType = reader.GetUInt8();
tagByteCount = reader.GetUInt16();
offset += 4;
}
catch (IOException)
{
directory.AddError("IPTC data segment ended mid-way through tag descriptor");
return;
}
if (offset + tagByteCount > length)
{
directory.AddError("Data for tag extends beyond end of IPTC segment");
return;
}
try
{
ProcessTag(reader, directory, directoryType, tagType, tagByteCount);
}
catch (IOException)
{
directory.AddError("Error processing IPTC tag");
return;
}
offset += tagByteCount;
}
}
/// <summary>
/// Performs the IPTC data extraction, adding found values to the specified instance of
/// <see cref="Com.Drew.Metadata.Metadata"/>
/// .
/// </summary>
public virtual void Extract([NotNull] SequentialReader reader, [NotNull] Com.Drew.Metadata.Metadata metadata, long length)
{
IptcDirectory directory = new IptcDirectory();
metadata.AddDirectory(directory);
int offset = 0;
// for each tag
while (offset < length)
{
// identifies start of a tag
short startByte;
try
{
startByte = reader.GetUInt8();
offset++;
}
catch (IOException)
{
directory.AddError("Unable to read starting byte of IPTC tag");
return;
}
if (startByte != unchecked ((int)(0x1c)))
{
// NOTE have seen images where there was one extra byte at the end, giving
// offset==length at this point, which is not worth logging as an error.
if (offset != length)
{
directory.AddError("Invalid IPTC tag marker at offset " + (offset - 1) + ". Expected '0x1c' but got '0x" + Sharpen.Extensions.ToHexString(startByte) + "'.");
}
return;
}
// we need at least five bytes left to read a tag
if (offset + 5 >= length)
{
directory.AddError("Too few bytes remain for a valid IPTC tag");
return;
}
int directoryType;
int tagType;
int tagByteCount;
try
{
directoryType = reader.GetUInt8();
tagType = reader.GetUInt8();
// TODO support Extended DataSet Tag (see 1.5(c), p14, IPTC-IIMV4.2.pdf)
tagByteCount = reader.GetUInt16();
offset += 4;
}
catch (IOException)
{
directory.AddError("IPTC data segment ended mid-way through tag descriptor");
return;
}
if (offset + tagByteCount > length)
{
directory.AddError("Data for tag extends beyond end of IPTC segment");
return;
}
try
{
ProcessTag(reader, directory, directoryType, tagType, tagByteCount);
}
catch (IOException)
{
directory.AddError("Error processing IPTC tag");
return;
}
offset += tagByteCount;
}
}
/// <summary>
/// Performs the IPTC data extraction, adding found values to the specified instance of
/// <see cref="Com.Drew.Metadata.Metadata"/>
/// .
/// </summary>
public virtual void Extract([NotNull] SequentialReader reader, [NotNull] Com.Drew.Metadata.Metadata metadata, long length)
{
IptcDirectory directory = new IptcDirectory();
metadata.AddDirectory(directory);
int offset = 0;
// for each tag
while (offset < length)
{
// identifies start of a tag
short startByte;
try
{
startByte = reader.GetUInt8();
offset++;
}
catch (IOException)
{
directory.AddError("Unable to read starting byte of IPTC tag");
return;
}
if (startByte != unchecked((int)(0x1c)))
{
// NOTE have seen images where there was one extra byte at the end, giving
// offset==length at this point, which is not worth logging as an error.
if (offset != length)
{
directory.AddError("Invalid IPTC tag marker at offset " + (offset - 1) + ". Expected '0x1c' but got '0x" + Sharpen.Extensions.ToHexString(startByte) + "'.");
}
return;
}
// we need at least five bytes left to read a tag
if (offset + 5 >= length)
{
directory.AddError("Too few bytes remain for a valid IPTC tag");
return;
}
int directoryType;
int tagType;
int tagByteCount;
try
{
directoryType = reader.GetUInt8();
tagType = reader.GetUInt8();
// TODO support Extended DataSet Tag (see 1.5(c), p14, IPTC-IIMV4.2.pdf)
tagByteCount = reader.GetUInt16();
offset += 4;
}
catch (IOException)
{
directory.AddError("IPTC data segment ended mid-way through tag descriptor");
return;
}
if (offset + tagByteCount > length)
{
directory.AddError("Data for tag extends beyond end of IPTC segment");
return;
}
try
{
ProcessTag(reader, directory, directoryType, tagType, tagByteCount);
}
catch (IOException)
{
directory.AddError("Error processing IPTC tag");
return;
}
offset += tagByteCount;
}
}
