public ByteBuffer synchronize(ByteBuffer b)
{
ByteBuffer bb = new ByteBuffer(b.Capacity);
while(b.Remaining >= 1) {
byte cur = b.Get();
bb.Put(cur);
if((cur&0xFF) == 0xFF && b.Remaining >=1 && b.Peek() == 0x00) {
//First part of synchronization
b.Get();
}
}
//We have finished filling the new bytebuffer, so set the limit, and rewind
bb.Limit = bb.Position;
bb.Rewind();
return bb;
}
public Id3v2Tag Read(ByteBuffer data, bool[] ID3Flags, byte version)
{
int tagSize = data.Limit;
byte[] b;
Id3v2Tag tag = new Id3v2Tag();
//----------------------------------------------------------------------------
//Traitement en cas d'Header Etendu==true (A COMPLETER)
if (version == Id3v2Tag.ID3V23 && ID3Flags[1])
ProcessExtendedHeader(data);
//----------------------------------------------------------------------------
//Extraction des champs de texte
int specSize = (version == Id3v2Tag.ID3V22) ? 3 : 4;
for (int a = 0; a < tagSize; a++) {
//Nom de la Frame
b = new byte[specSize];
if(data.Remaining <= specSize)
break;
data.Get(b);
string field = new string(System.Text.Encoding.ASCII.GetChars(b));
if (b[0] == 0)
break;
//La longueur du texte contenu dans la Frame
int frameSize = ReadInteger(data, version);
if ((frameSize > data.Remaining) || frameSize <= 0){
//ignore empty frames
break;
}
b = new byte[ frameSize + ((version == Id3v2Tag.ID3V23) ? 2 : 0) ];
data.Get(b);
if( "" != field) {
Id3Frame f = CreateId3Frame(field, b, version);
if(f != null)
tag.Add(f);
}
}
return tag;
}
private int ReadInteger(ByteBuffer bb, int version)
{
int value = 0;
if(version == Id3v2Tag.ID3V23)
value += (bb.Get()& 0xFF) << 24;
value += (bb.Get()& 0xFF) << 16;
value += (bb.Get()& 0xFF) << 8;
value += (bb.Get()& 0xFF);
return value;
}
//Process the Extended Header in the ID3v2 Tag, returns the number of bytes to skip
private int ProcessExtendedHeader(ByteBuffer data)
{
//TODO Verify that we have an syncsfe int
byte[] exthead = new byte [4];
data.Get(exthead);
int extsize = ReadInteger(data, Id3v2Tag.ID3V23);
// The extended header size includes those first four bytes.
data.Position = data.Position + extsize;
return extsize;
}
