public void read(final RandomAccessFile file) throws TagException, IOException {
final int size;
final byte[] buffer = new byte[4];
if (seek(file) == false) {
throw new TagNotFoundException(getIdentifier() + " tag not found");
}
// read the major and minor @version number & flags byte
file.read(buffer, 0, 3);
if ((buffer[0] != 3) || (buffer[1] != 0)) {
throw new TagNotFoundException(getIdentifier() + " tag not found");
}
setMajorVersion(buffer[0]);
setRevision(buffer[1]);
this.unsynchronization = (buffer[2] & TagConstant.MASK_V23_UNSYNCHRONIZATION) != 0;
this.extended = (buffer[2] & TagConstant.MASK_V23_EXTENDED_HEADER) != 0;
this.experimental = (buffer[2] & TagConstant.MASK_V23_EXPERIMENTAL) != 0;
// read the size
file.read(buffer, 0, 4);
size = byteArrayToSize(buffer);
final long filePointer = file.getFilePointer();
if (this.extended) {
// int is 4 bytes.
final int extendedHeaderSize = file.readInt();
// the extended header is only 6 or 10 bytes.
if (extendedHeaderSize != 6 && extendedHeaderSize != 10) {
throw new InvalidTagException("Invalid Extended Header Size.");
}
file.read(buffer, 0, 2);
this.crcDataFlag = (buffer[0] & TagConstant.MASK_V23_CRC_DATA_PRESENT) != 0;
// if it's 10 bytes, the CRC flag must be set
// and if it's 6 bytes, it must not be set
if (((extendedHeaderSize == 10) && (this.crcDataFlag == false))
|| ((extendedHeaderSize == 6) && (this.crcDataFlag == true))) {
throw new InvalidTagException("CRC Data flag not set correctly.");
}
this.paddingSize = file.readInt();
if ((extendedHeaderSize == 10) && this.crcDataFlag) {
this.crcData = file.readInt();
}
}
ID3v2_3Frame next;
this.clearFrameMap();
// read all the frames.
this.setFileReadBytes(size);
AbstractID3v2.resetPaddingCounter();
while ((file.getFilePointer() - filePointer) <= size) {
try {
next = new ID3v2_3Frame(file, this);
final TagIdentifier id = next.getIdentifier();
if (this.hasFrame(id)) {
this.appendDuplicateFrameId(id + "; ");
this.incrementDuplicateBytes(this.getFrame(id).getSize());
}
this.setFrame(next);
} catch (InvalidTagException ex) {
if (ex.getMessage().equals("Found empty frame")) {
this.incrementEmptyFrameBytes(10);
} else {
this.incrementInvalidFrameBytes();
}
}
}
this.setPaddingSize(getPaddingCounter());
}
