/// <summary>
/// Reads an IFD from file at position <paramref name="offset"/> relative
/// to <paramref name="baseOffset"/>.
/// </summary>
/// <param name="baseOffset">
/// A <see cref="System.Int64"/> with the base offset which every offset
/// in IFD is relative to.
/// </param>
/// <param name="offset">
/// A <see cref="System.UInt32"/> with the offset of the IFD relative to
/// <paramref name="baseOffset"/>
/// </param>
/// <param name="maxOffset">
/// A <see cref="System.UInt32"/> with the maximal offset to consider for
/// the IFD.
/// </param>
/// <returns>
/// A <see cref="System.UInt32"/> with the offset of the next IFD, the
/// offset is also relative to <paramref name="baseOffset"/>
/// </returns>
uint ReadIFD(long baseOffset, uint offset, uint maxOffset)
{
long length = 0;
try {
length = file.Length;
} catch (Exception) {
// Use a safety-value of 4 gigabyte.
length = 1073741824L * 4;
}
if (baseOffset + offset > length)
{
file.MarkAsCorrupt("Invalid IFD offset");
return(0);
}
var directory = new IFDDirectory();
file.Seek(baseOffset + offset, SeekOrigin.Begin);
ushort entry_count = ReadUShort();
if (file.Tell + 12 * entry_count > baseOffset + maxOffset)
{
file.MarkAsCorrupt("Size of entries exceeds possible data size");
return(0);
}
ByteVector entry_datas = file.ReadBlock(12 * entry_count);
uint next_offset = ReadUInt();
for (int i = 0; i < entry_count; i++)
{
ByteVector entry_data = entry_datas.Mid(i * 12, 12);
ushort entry_tag = entry_data.Mid(0, 2).ToUShort(is_bigendian);
ushort type = entry_data.Mid(2, 2).ToUShort(is_bigendian);
uint value_count = entry_data.Mid(4, 4).ToUInt(is_bigendian);
ByteVector offset_data = entry_data.Mid(8, 4);
IFDEntry entry = CreateIFDEntry(entry_tag, type, value_count, baseOffset, offset_data, maxOffset);
if (entry == null)
{
continue;
}
if (directory.ContainsKey(entry.Tag))
{
directory.Remove(entry.Tag);
}
directory.Add(entry.Tag, entry);
}
FixupDirectory(baseOffset, directory);
structure.directories.Add(directory);
return(next_offset);
}
/// <summary>
/// Renders a complete entry together with the data. The entry itself
/// is stored in <paramref name="entry_data"/> and the data of the
/// entry is stored in <paramref name="offset_data"/> if it cannot be
/// stored in the offset. This method is called for every <see
/// cref="IFDEntry"/> of this IFD and can be overwritten in subclasses
/// to provide special behavior.
/// </summary>
/// <param name="entry">
/// A <see cref="IFDEntry"/> with the entry to render.
/// </param>
/// <param name="entry_data">
/// A <see cref="ByteVector"/> to add the entry to.
/// </param>
/// <param name="offset_data">
/// A <see cref="ByteVector"/> to add the entry data to if it cannot be
/// stored in the offset field.
/// </param>
/// <param name="data_offset">
/// A <see cref="System.UInt32"/> with the offset, were the data of the
/// entries starts. It is needed to adjust the offsets of the entries
/// itself.
/// </param>
protected virtual void RenderEntryData(IFDEntry entry, ByteVector entry_data, ByteVector offset_data, uint data_offset)
{
ushort tag = (ushort)entry.Tag;
uint offset = (uint)(data_offset + offset_data.Count);
ushort type;
uint count;
ByteVector data = entry.Render(is_bigendian, offset, out type, out count);
// store data in offset, if it is smaller than 4 byte
if (data.Count <= 4)
{
while (data.Count < 4)
{
data.Add("\0");
}
offset = data.ToUInt(is_bigendian);
data = null;
}
// preserve word boundary of offsets
if (data != null && data.Count % 2 != 0)
{
data.Add("\0");
}
RenderEntry(entry_data, tag, type, count, offset);
offset_data.Add(data);
}
/// <summary>
/// Adds an <see cref="IFDEntry"/> to the IFD, if it is not already
/// contained in, it fails otherwise.
/// </summary>
/// <param name="directory">
/// A <see cref="System.Int32"/> value with the directory index that
/// should contain the tag that will be added.
/// </param>
/// <param name="entry">
/// A <see cref="IFDEntry"/> to add to the IFD.
/// </param>
public void AddEntry(int directory, IFDEntry entry)
{
while (directory >= directories.Count)
directories.Add (new IFDDirectory ());
directories [directory].Add (entry.Tag, entry);
}
public void SetEntry(int directory, IFDEntry entry)
{
if (ContainsTag(directory, entry.Tag))
{
RemoveTag(directory, entry.Tag);
}
AddEntry(directory, entry);
}
public void AddEntry(int directory, IFDEntry entry)
{
while (directory >= directories.Count)
{
directories.Add(new IFDDirectory());
}
directories[directory].Add(entry.Tag, entry);
}
protected virtual void RenderEntryData(IFDEntry entry, ByteVector entry_data, ByteVector offset_data, uint data_offset)
{
ushort tag = (ushort)entry.Tag;
uint offset = (uint)(data_offset + offset_data.Count);
ushort type;
uint count;
ByteVector data = entry.Render(is_bigendian, offset, out type, out count);
if (data.Count <= 4)
{
while (data.Count < 4)
{
data.Add("\0");
}
offset = data.ToUInt(is_bigendian);
data = null;
}
if (data != null && data.Count % 2 != 0)
{
data.Add("\0");
}
RenderEntry(entry_data, tag, type, count, offset);
offset_data.Add(data);
}
/// <summary>
/// Renders a complete entry together with the data. The entry itself
/// is stored in <paramref name="entry_data"/> and the data of the
/// entry is stored in <paramref name="offset_data"/> if it cannot be
/// stored in the offset. This method is called for every <see
/// cref="IFDEntry"/> of this IFD and can be overwritten in subclasses
/// to provide special behavior.
/// </summary>
/// <param name="entry">
/// A <see cref="IFDEntry"/> with the entry to render.
/// </param>
/// <param name="entry_data">
/// A <see cref="ByteVector"/> to add the entry to.
/// </param>
/// <param name="offset_data">
/// A <see cref="ByteVector"/> to add the entry data to if it cannot be
/// stored in the offset field.
/// </param>
/// <param name="data_offset">
/// A <see cref="System.UInt32"/> with the offset, were the data of the
/// entries starts. It is needed to adjust the offsets of the entries
/// itself.
/// </param>
protected virtual void RenderEntryData(IFDEntry entry, ByteVector entry_data, ByteVector offset_data, uint data_offset)
{
ushort tag = (ushort) entry.Tag;
uint offset = (uint) (data_offset + offset_data.Count);
ushort type;
uint count;
ByteVector data = entry.Render (is_bigendian, offset, out type, out count);
// store data in offset, if it is smaller than 4 byte
if (data.Count <= 4) {
while (data.Count < 4)
data.Add ("\0");
offset = data.ToUInt (is_bigendian);
data = null;
}
// preserve word boundary of offsets
if (data != null && data.Count % 2 != 0)
data.Add ("\0");
RenderEntry (entry_data, tag, type, count, offset);
offset_data.Add (data);
}
/// <summary>
/// Adds an <see cref="IFDEntry"/> to the IFD. If it is already contained
/// in the IFD, it is overwritten.
/// </summary>
/// <param name="directory">
/// A <see cref="System.Int32"/> value with the directory index that
/// contains the tag that will be set.
/// </param>
/// <param name="entry">
/// A <see cref="IFDEntry"/> to add to the IFD.
/// </param>
public void SetEntry(int directory, IFDEntry entry)
{
if (ContainsTag (directory, entry.Tag))
RemoveTag (directory, entry.Tag);
AddEntry (directory, entry);
}
internal static void WriteTaglibTiffDirEntry(ushort key, IFDEntry entry, string indent)
{
if (entry is TagLib.IFD.Entries.ShortIFDEntry ifdShort)
{
Console.WriteLine("{0}TIFF entry = [{1}] = {2}", indent, ifdShort.Tag, ifdShort.Value);
}
else if (entry is TagLib.IFD.Entries.LongIFDEntry ifdLong)
{
Console.WriteLine("{0}TIFF entry = [{1}] = {2}", indent, ifdLong.Tag, ifdLong.Value);
}
else if (entry is TagLib.IFD.Entries.StringIFDEntry ifdString)
{
Console.WriteLine("{0}TIFF entry = [{1}] = \"{2}\"", indent, ifdString.Tag, ifdString.Value);
}
else if (entry is TagLib.IFD.Entries.UserCommentIFDEntry ifdUserComment)
{
Console.WriteLine("{0}TIFF entry = [{1}] = \"{2}\"", indent, ifdUserComment.Tag, ifdUserComment.Value);
}
else if (entry is TagLib.IFD.Entries.RationalIFDEntry ifdRational)
{
Console.WriteLine("{0}TIFF entry = [{1}] = {2}/{3}", indent, ifdRational.Tag, ifdRational.Value.Numerator, ifdRational.Value.Denominator);
}
else if (entry is TagLib.IFD.Entries.SRationalIFDEntry ifdSRational)
{
Console.WriteLine("{0}TIFF entry = [{1}] = {2}/{3}", indent, ifdSRational.Tag, ifdSRational.Value.Numerator, ifdSRational.Value.Denominator);
}
else if (entry is TagLib.IFD.Entries.ShortArrayIFDEntry ifdShortArray)
{
Console.Write("{0}TIFF entry = [{1}] =", indent, ifdShortArray.Tag);
foreach (var x in ifdShortArray.Values)
{
Console.Write(" {0}", x);
}
Console.WriteLine();
}
else if (entry is TagLib.IFD.Entries.RationalArrayIFDEntry ifdRationalArray)
{
Console.Write("{0}TIFF entry = [{1}] =", indent, ifdRationalArray.Tag);
foreach (var x in ifdRationalArray.Values)
{
Console.Write(" {0}/{1}", x.Numerator, x.Denominator);
}
Console.WriteLine();
}
else if (entry is TagLib.IFD.Entries.ThumbnailDataIFDEntry ifdThumbnailData)
{
Console.WriteLine("{0}TIFF entry = [{1}] has {2} bytes of thumbnail data", indent, ifdThumbnailData.Tag, ifdThumbnailData.Data?.Count);
}
else if (entry is TagLib.IFD.Entries.ByteVectorIFDEntry ifdByteVector)
{
Console.WriteLine("{0}TIFF entry = [{1}] has {2} bytes of byte vector data", indent, ifdByteVector.Tag, ifdByteVector.Data?.Count);
}
else if (entry is TagLib.IFD.Entries.SubIFDEntry ifdSubEntry)
{
Console.WriteLine("{0}TIFF entry = [{1}] has {2} subentries in {3} directories", indent, ifdSubEntry.Tag, ifdSubEntry.ChildCount, ifdSubEntry.Count);
foreach (var dir in ifdSubEntry.Structure.Directories)
{
foreach (var subentry in dir)
{
WriteTaglibTiffDirEntry(subentry.Key, subentry.Value, indent + " ");
}
}
}
else if (entry is TagLib.IFD.Entries.UndefinedIFDEntry ifdUndefined)
{
Console.WriteLine("{0}TIFF entry = [{1}] has {2} bytes of undefined data", indent, ifdUndefined.Tag, ifdUndefined.Data?.Count);
}
else
{
Console.WriteLine("{0}TIFF entry = [{1}] is {2}", indent, entry.Tag, entry.GetType());
}
}
/// <summary>
/// Reads an IFD from file at position <paramref name="offset"/> relative
/// to <paramref name="base_offset"/>.
/// </summary>
/// <param name="base_offset">
/// A <see cref="System.Int64"/> with the base offset which every offset
/// in IFD is relative to.
/// </param>
/// <param name="offset">
/// A <see cref="System.UInt32"/> with the offset of the IFD relative to
/// <paramref name="base_offset"/>
/// </param>
/// <param name="max_offset">
/// A <see cref="System.UInt32"/> with the maximal offset to consider for
/// the IFD.
/// </param>
/// <returns>
/// A <see cref="System.UInt32"/> with the offset of the next IFD, the
/// offset is also relative to <paramref name="base_offset"/>
/// </returns>
private uint ReadIFD(long base_offset, uint offset, uint max_offset)
{
long length = 0;
try {
length = file.Length;
} catch (Exception) {
// Use a safety-value of 4 gigabyte.
length = 1073741824L * 4;
}
if (base_offset + offset > length)
{
file.MarkAsCorrupt("Invalid IFD offset");
return(0);
}
var directory = new IFDDirectory();
file.Seek(base_offset + offset, SeekOrigin.Begin);
ushort entry_count = ReadUShort();
if (file.Tell + 12 * entry_count > base_offset + max_offset)
{
file.MarkAsCorrupt("Size of entries exceeds possible data size");
return(0);
}
ByteVector entry_datas = file.ReadBlock(12 * entry_count);
uint next_offset = ReadUInt();
for (int i = 0; i < entry_count; i++)
{
ByteVector entry_data = entry_datas.Mid(i * 12, 12);
ushort entry_tag = entry_data.Mid(0, 2).ToUShort(is_bigendian);
ushort type = entry_data.Mid(2, 2).ToUShort(is_bigendian);
uint value_count = entry_data.Mid(4, 4).ToUInt(is_bigendian);
ByteVector offset_data = entry_data.Mid(8, 4);
// Even if the value count represents a single bytes it's impossible
// for the count plus the base offset to be bigger than the entire file,
// ignore this entry and keep going
if (value_count + base_offset > max_offset)
{
file.MarkAsCorrupt("Value count + base offset is greater than the maximum possible offset");
continue;
}
IFDEntry entry = CreateIFDEntry(entry_tag, type, value_count, base_offset, offset_data, max_offset);
if (entry == null)
{
continue;
}
if (directory.ContainsKey(entry.Tag))
{
directory.Remove(entry.Tag);
}
directory.Add(entry.Tag, entry);
}
FixupDirectory(base_offset, directory);
structure.directories.Add(directory);
return(next_offset);
}
