private static string GetTagText(FrameBase tag)
{
var frameText = tag as FrameText;
if (frameText != null)
return frameText.Text;
var frameFullText = tag as FrameFullText;
if (frameFullText != null)
return frameFullText.Text;
return null;
}
private void SetFlags(FrameBase frame, ushort flags)
{
frame.TagAlter = GetTagAlter(flags);
frame.FileAlter = GetFileAlter(flags);
frame.ReadOnly = GetReadOnly(flags);
frame.Compression = GetCompression(flags);
frame.Encryption = GetEncryption(flags);
frame.Unsynchronisation = GetUnsynchronisation(flags);
frame.DataLength = GetDataLength(flags);
}
private ushort GetFlags(FrameBase frame)
{
ushort flags = 0;
SetTagAlter(frame.TagAlter, ref flags);
SetFileAlter(frame.FileAlter, ref flags);
SetReadOnly(frame.ReadOnly, ref flags);
SetGrouping(frame.Group.HasValue, ref flags);
SetCompression(frame.Compression, ref flags);
SetEncryption(frame.Encryption, ref flags);
SetUnsynchronisation(frame.Unsynchronisation, ref flags);
SetDataLength(frame.DataLength, ref flags);
return flags;
}
/// <summary>
/// Build a binary data frame form the frame object.
/// </summary>
/// <param name="frame">ID3 Frame</param>
/// <returns>binary frame representation</returns>
public byte[] Make(FrameBase frame, out ushort flags)
{
flags = GetFlags(frame);
var buffer = frame.Make();
var memoryStream = new MemoryStream();
var writer = new BinaryWriter(memoryStream);
if (frame.Group.HasValue == true)
writer.Write((byte)frame.Group);
if (frame.Compression == true)
{
switch (Version)
{
case 3:
{
writer.Write(Swap.Int32(buffer.Length));
break;
}
case 4:
{
writer.Write(Sync.UnsafeBigEndian(Swap.UInt32((uint)buffer.Length)));
break;
}
default:
{
throw new NotImplementedException("ID3v2 Version " + Version + " is not supported.");
}
}
var buf = new byte[2048];
var deflater = new Deflater(Deflater.BEST_COMPRESSION);
deflater.SetInput(buffer, 0, buffer.Length);
deflater.Finish();
while (!deflater.IsNeedingInput)
{
int len = deflater.Deflate(buf, 0, buf.Length);
if (len <= 0)
{
break;
}
memoryStream.Write(buf, 0, len);
}
if (!deflater.IsNeedingInput)
{
//TODO: Skip and remove invalid frames.
throw new InvalidFrameException("Can't decompress frame '" + frame.FrameId + "' missing data");
}
}
else
{
memoryStream.Write(buffer, 0, buffer.Length);
}
if (frame.Encryption == true)
{
//TODO: Encryption
throw new NotImplementedException("Encryption is not implemented, consequently it is not supported.");
}
if (frame.Unsynchronisation == true)
{
MemoryStream synchStream = new MemoryStream();
Sync.Unsafe(memoryStream, synchStream, (uint)memoryStream.Position);
memoryStream = synchStream;
}
return memoryStream.ToArray();
}