private static void WriteDirectory(BinaryWriter writer, Dictionary <ushort, ExifValue> tags, List <IFDEntry> entries, long ifdOffset)
{
writer.BaseStream.Position = ifdOffset;
long nextIFDPointerOffset = ifdOffset + sizeof(ushort) + ((long)entries.Count * IFDEntry.SizeOf);
writer.Write((ushort)entries.Count);
foreach (IFDEntry entry in entries.OrderBy(e => e.Tag))
{
entry.Write(writer);
if (!ExifValueTypeUtil.ValueFitsInOffsetField(entry.Type, entry.Count))
{
long oldPosition = writer.BaseStream.Position;
writer.BaseStream.Position = entry.Offset;
writer.Write(tags[entry.Tag].Data.AsArrayOrToArray());
writer.BaseStream.Position = oldPosition;
}
}
writer.BaseStream.Position = nextIFDPointerOffset;
// There is only one IFD in this directory.
writer.Write(0);
}
private string GetValueStringFromOffset()
{
string valueString;
ExifValueType type = entry.Type;
uint count = entry.Count;
uint offset = entry.Offset;
if (count == 0)
{
return(string.Empty);
}
int typeSizeInBytes = ExifValueTypeUtil.GetSizeInBytes(type);
if (typeSizeInBytes == 1)
{
byte[] bytes = new byte[count];
if (offsetIsBigEndian)
{
switch (count)
{
case 1:
bytes[0] = (byte)((offset >> 24) & 0x000000ff);
break;
case 2:
bytes[0] = (byte)((offset >> 24) & 0x000000ff);
bytes[1] = (byte)((offset >> 16) & 0x000000ff);
break;
case 3:
bytes[0] = (byte)((offset >> 24) & 0x000000ff);
bytes[1] = (byte)((offset >> 16) & 0x000000ff);
bytes[2] = (byte)((offset >> 8) & 0x000000ff);
break;
case 4:
bytes[0] = (byte)((offset >> 24) & 0x000000ff);
bytes[1] = (byte)((offset >> 16) & 0x000000ff);
bytes[2] = (byte)((offset >> 8) & 0x000000ff);
bytes[3] = (byte)(offset & 0x000000ff);
break;
}
}
else
{
switch (count)
{
case 1:
bytes[0] = (byte)(offset & 0x000000ff);
break;
case 2:
bytes[0] = (byte)(offset & 0x000000ff);
bytes[1] = (byte)((offset >> 8) & 0x000000ff);
break;
case 3:
bytes[0] = (byte)(offset & 0x000000ff);
bytes[1] = (byte)((offset >> 8) & 0x000000ff);
bytes[2] = (byte)((offset >> 16) & 0x000000ff);
break;
case 4:
bytes[0] = (byte)(offset & 0x000000ff);
bytes[1] = (byte)((offset >> 8) & 0x000000ff);
bytes[2] = (byte)((offset >> 16) & 0x000000ff);
bytes[3] = (byte)((offset >> 24) & 0x000000ff);
break;
}
}
if (type == ExifValueType.Ascii)
{
valueString = Encoding.UTF8.GetString(bytes).TrimEnd('\0');
}
else if (count == 1)
{
valueString = bytes[0].ToString(CultureInfo.InvariantCulture);
}
else
{
StringBuilder builder = new();
uint lastItemIndex = count - 1;
for (int i = 0; i < count; i++)
{
builder.Append(bytes[i].ToString(CultureInfo.InvariantCulture));
if (i < lastItemIndex)
{
builder.Append(',');
}
}
valueString = builder.ToString();
}
}
else if (typeSizeInBytes == 2)
{
ushort[] values = new ushort[count];
if (offsetIsBigEndian)
{
switch (count)
{
case 1:
values[0] = (ushort)((offset >> 16) & 0x0000ffff);
break;
case 2:
values[0] = (ushort)((offset >> 16) & 0x0000ffff);
values[1] = (ushort)(offset & 0x0000ffff);
break;
}
}
else
{
switch (count)
{
case 1:
values[0] = (ushort)(offset & 0x0000ffff);
break;
case 2:
values[0] = (ushort)(offset & 0x0000ffff);
values[1] = (ushort)((offset >> 16) & 0x0000ffff);
break;
}
}
if (count == 1)
{
switch (type)
{
case ExifValueType.SShort:
valueString = ((short)values[0]).ToString(CultureInfo.InvariantCulture);
break;
case ExifValueType.Short:
default:
valueString = values[0].ToString(CultureInfo.InvariantCulture);
break;
}
}
else
{
switch (type)
{
case ExifValueType.SShort:
valueString = ((short)values[0]).ToString(CultureInfo.InvariantCulture) + "," +
((short)values[1]).ToString(CultureInfo.InvariantCulture);
break;
case ExifValueType.Short:
default:
valueString = values[0].ToString(CultureInfo.InvariantCulture) + "," +
values[1].ToString(CultureInfo.InvariantCulture);
break;
}
}
}
else
{
valueString = offset.ToString(CultureInfo.InvariantCulture);
}
return(valueString);
}
private static Dictionary <ExifPropertyPath, ExifValue> ConvertIFDEntriesToMetadataEntries(EndianBinaryReader reader, List <ParserIFDEntry> entries)
{
Dictionary <ExifPropertyPath, ExifValue> items = new(entries.Count);
bool swapNumberByteOrder = reader.Endianess == Endianess.Big;
for (int i = 0; i < entries.Count; i++)
{
ParserIFDEntry entry = entries[i];
byte[] propertyData;
if (entry.OffsetFieldContainsValue)
{
propertyData = entry.GetValueBytesFromOffset();
if (propertyData == null)
{
continue;
}
}
else
{
long bytesToRead = entry.Count * ExifValueTypeUtil.GetSizeInBytes(entry.Type);
// Skip any tags that are empty or larger than 2 GB.
if (bytesToRead == 0 || bytesToRead > int.MaxValue)
{
continue;
}
uint offset = entry.Offset;
if ((offset + bytesToRead) > reader.Length)
{
continue;
}
reader.Position = offset;
propertyData = reader.ReadBytes((int)bytesToRead);
if (swapNumberByteOrder)
{
// Paint.NET converts all multi-byte numbers to little-endian.
switch (entry.Type)
{
case ExifValueType.Short:
case ExifValueType.SShort:
propertyData = SwapShortArrayToLittleEndian(propertyData, entry.Count);
break;
case ExifValueType.Long:
case ExifValueType.SLong:
case ExifValueType.Float:
propertyData = SwapLongArrayToLittleEndian(propertyData, entry.Count);
break;
case ExifValueType.Rational:
case ExifValueType.SRational:
propertyData = SwapRationalArrayToLittleEndian(propertyData, entry.Count);
break;
case ExifValueType.Double:
propertyData = SwapDoubleArrayToLittleEndian(propertyData, entry.Count);
break;
case ExifValueType.Byte:
case ExifValueType.Ascii:
case ExifValueType.Undefined:
default:
break;
}
}
}
items.TryAdd(new ExifPropertyPath(entry.Section, entry.Tag), new ExifValue(entry.Type, propertyData));
}
return(items);
}
