/// <summary>
/// Creates the IPTC-NAA caption record.
/// </summary>
/// <param name="value">A string containing the caption.</param>
/// <param name="captionRecord">The byte array containing the caption data.</param>
/// <returns><c>true</c> if the <paramref name="value"/> was converted successfully; otherwise, <c>false</c></returns>
internal bool TryCreateCaptionRecord(string value, out byte[] captionRecord)
{
if (!createdCaptionRecord)
{
createdCaptionRecord = true;
if (!string.IsNullOrEmpty(value))
{
int captionLength = Encoding.ASCII.GetByteCount(value);
if (captionLength < MaxCaptionLength)
{
IPTCCaption captionHeader = new IPTCCaption
{
version = new IPTCRecordVersion(IPTCVersion),
tag = new IPTCTag(IPTCRecord.App2, App2DataSets.Caption, (ushort)captionLength)
};
captionRecordBytes = new byte[IPTCCaption.SizeOf + captionLength];
captionHeader.Write(captionRecordBytes);
Encoding.ASCII.GetBytes(value, 0, value.Length, captionRecordBytes, IPTCCaption.SizeOf);
}
}
}
captionRecord = captionRecordBytes;
return(captionRecordBytes != null);
}
/// <summary>
/// Creates the IPTC-NAA caption record.
/// </summary>
/// <param name="value">A string containing the caption.</param>
/// <param name="captionRecord">The byte array containing the caption data.</param>
/// <returns><c>true</c> if the <paramref name="value"/> was converted successfully; otherwise, <c>false</c></returns>
internal static bool TryCreateCaptionRecord(string value, out byte[] captionRecord)
{
if (!string.IsNullOrEmpty(value))
{
int captionLength = Encoding.ASCII.GetByteCount(value);
if (captionLength < MaxCaptionLength)
{
IPTCCaption captionHeader = new IPTCCaption
{
version = CreateVersionRecord(),
tag = new IPTCTag(CaptionType, (ushort)captionLength)
};
captionRecord = new byte[IPTCCaption.SizeOf + captionLength];
captionHeader.Write(captionRecord);
Encoding.ASCII.GetBytes(value, 0, value.Length, captionRecord, IPTCCaption.SizeOf);
return(true);
}
}
captionRecord = null;
return(false);
}
/// <summary>
/// Converts the caption from unmanaged memory.
/// </summary>
/// <param name="data">The data.</param>
internal static string CaptionFromMemory(IntPtr data)
{
if (data != IntPtr.Zero)
{
IPTCCaption captionHeader = new IPTCCaption(data);
string caption = string.Empty;
if (captionHeader.tag.length > 0)
{
byte[] bytes = new byte[captionHeader.tag.length];
Marshal.Copy(new IntPtr(data.ToInt64() + IPTCCaption.SizeOf), bytes, 0, bytes.Length);
caption = Encoding.ASCII.GetString(bytes);
}
return(caption);
}
return(null);
}
