private FrameInfo(string identifier, long position, int size, FrameStatusFlag statusflags, FrameFormatFlags formatflags)
{
this.identifier = identifier;
this.position = position;
this.size = size;
this.statusflags = statusflags;
this.formatflags = formatflags;
}
public FrameInfo(Stream stream, TagHeader header, bool checkUnsynchronisation)
{
byte[] buffer = new byte[10];
stream.Read(buffer, 0, 10);
this.identifier = Encoding.ASCII.GetString(buffer, 0, 4);
this.statusflags = (FrameStatusFlag)buffer[8];
this.formatflags = (FrameFormatFlags)buffer[9];
int sizeS = BinaryConverter.ToInt32(buffer, 4, true); // sizeS <= sizeU
int sizeU = BinaryConverter.ToInt32(buffer, 4, false); // sizeU >= sizeS
this.size = sizeS;
if (sizeS != sizeU && checkUnsynchronisation)
{
int maxsize = header.Size - (int)(stream.Position - header.FirstFramePosition);
long p = stream.Position;
if (sizeU == maxsize)
{
stream.Seek(sizeS, SeekOrigin.Current);
BinaryConverter.Skip(0, stream, header.FirstFramePosition + (long)header.Size);
FrameInfo frameS = new FrameInfo(stream, header, false);
stream.Seek(p, SeekOrigin.Begin);
if (!char.IsLetterOrDigit(frameS.Identifier, 0) ||
!char.IsLetterOrDigit(frameS.Identifier, 1) ||
!char.IsLetterOrDigit(frameS.Identifier, 2) ||
!char.IsLetterOrDigit(frameS.Identifier, 3) ||
frameS.Identifier != frameS.Identifier.ToUpper())
{
size = sizeU;
}
}
else
{
stream.Seek(sizeS, SeekOrigin.Current);
BinaryConverter.Skip(0, stream, header.FirstFramePosition + (long)header.Size);
FrameInfo frameS = new FrameInfo(stream, header, false);
stream.Seek(p, SeekOrigin.Begin);
stream.Seek(sizeU, SeekOrigin.Current);
BinaryConverter.Skip(0, stream, header.FirstFramePosition + (long)header.Size);
FrameInfo frameU = new FrameInfo(stream, header, false);
stream.Seek(p, SeekOrigin.Begin);
if (char.IsLetterOrDigit(frameS.Identifier, 0) &&
char.IsLetterOrDigit(frameS.Identifier, 1) &&
char.IsLetterOrDigit(frameS.Identifier, 2) &&
char.IsLetterOrDigit(frameS.Identifier, 3) &&
frameS.Identifier == frameS.Identifier.ToUpper())
{
size = sizeS;
}
else if (char.IsLetterOrDigit(frameU.Identifier, 0) &&
char.IsLetterOrDigit(frameU.Identifier, 1) &&
char.IsLetterOrDigit(frameU.Identifier, 2) &&
char.IsLetterOrDigit(frameU.Identifier, 3) &&
frameU.Identifier == frameU.Identifier.ToUpper())
{
size = sizeU;
}
else
throw new Exception("An error occured due to an invalid Unsynchronized integer.");
}
}
this.position = stream.Position;
stream.Seek(size, SeekOrigin.Current);
}