/// <summary>
/// Internally parses the current data and loads all fields.
/// </summary>
protected void ParseData()
{
if ((m_Data[0] != (byte)'I') || (m_Data[1] != (byte)'D') || (m_Data[2] != (byte)'3'))
{
throw new InvalidDataException(string.Format("Missing ID3 identifier!"));
}
Version = m_Data[3];
m_Revision = m_Data[4];
Flags = CheckFlags(m_Data[5]);
m_BodySize = ID3v2DeUnsync.Int32(m_Data, 6);
}
/// <summary>
/// Parses the specified buffer starting at index to load all data for this frame
/// This function will throw exceptions on parser errors.
/// </summary>
/// <param name="reader">FrameReader to read from.</param>
void ParseVersion4(DataFrameReader reader)
{
if ((m_Header.TagHeader.Flags & ID3v2HeaderFlags.Unsynchronisation) == 0)
{
// no full unsync done, check if we have to unsync now
if (m_Header.Flags.Unsynchronisation)
{
m_Content = ID3v2DeUnsync.Buffer(m_Content);
}
}
if (m_Header.Flags.Compression)
{
m_Content = Decompress(m_Content);
}
if (m_Header.Flags.Encryption)
{
m_Content = Decrypt(m_Content);
}
}
/// <summary>
/// Reads the header (check <see cref="State"/> before usage).
/// </summary>
/// <returns></returns>
public ID3v2Header ReadHeader(out byte[] tagData)
{
if (State != ID3v2ReaderState.ReadHeader)
{
throw new InvalidOperationException(string.Format("Cannot read header at state {0}", State));
}
var header = new ID3v2Header();
if (!header.Parse(m_Reader))
{
tagData = null;
return(null);
}
m_BodyBytes = header.BodySize;
if ((header.Flags & ID3v2HeaderFlags.Footer) != 0)
{
m_BodyBytes -= 10;
}
State++;
if (header.Version < 2)
{
tagData = null;
return(null);
}
tagData = m_Reader.GetBuffer(header.HeaderSize + header.BodySize);
var bodyData = tagData.GetRange(header.HeaderSize);
// need to unsync whole tag?
if ((header.Flags & ID3v2HeaderFlags.Unsynchronisation) != 0)
{
bodyData = ID3v2DeUnsync.Buffer(bodyData);
m_BodyBytes = bodyData.Length;
}
// update reader (use cached data)
m_Header = header;
m_Reader = new DataFrameReader(bodyData);
return(header);
}
bool ParseVersion4(DataFrameReader reader)
{
if (!reader.EnsureBuffer(4))
{
return false;
}
// calc size
int size = ID3v2DeUnsync.Int32(reader.Read(0, 4), 0);
// get data
if (!reader.EnsureBuffer(size))
{
return false;
}
m_Data = reader.GetBuffer(size);
// get flags
m_Flags = ID3v2ExtendedHeaderFlags.FromID3v24(m_Data);
return true;
}