public final void readInputStream(InputStream input) throws IOException, ID3ReaderException {
int rc;
readerPosition = 0;
char[] tagHeaderSource = readBytes(input, HEADER_LENGTH);
tagHeader = createTagHeader(tagHeaderSource);
if (tagHeader == null) {
onNoTagHeaderFound();
} else {
rc = onStartTagHeader(tagHeader);
if (rc == ACTION_SKIP) {
onEndTag();
} else {
while (readerPosition < tagHeader.getSize()) {
FrameHeader frameHeader = createFrameHeader(readBytes(input, HEADER_LENGTH));
if (checkForNullString(frameHeader.getId())) {
break;
} else {
rc = onStartFrameHeader(frameHeader, input);
if (rc == ACTION_SKIP) {
if (frameHeader.getSize() + readerPosition > tagHeader.getSize()) {
break;
} else {
skipBytes(input, frameHeader.getSize());
}
}
}
}
onEndTag();
}
}
}
private FrameHeader createFrameHeader(char[] source) throws ID3ReaderException {
if (source.length != HEADER_LENGTH) {
throw new ID3ReaderException("Length of header must be " + HEADER_LENGTH);
}
String id = new String(source, 0, FRAME_ID_LENGTH);
int size =
(((int) source[4]) << 24)
| (((int) source[5]) << 16)
| (((int) source[6]) << 8)
| source[7];
if (tagHeader != null && tagHeader.getVersion() >= 0x0400) {
size = unsynchsafe(size);
}
char flags = (char) ((source[8] << 8) | source[9]);
return new FrameHeader(id, size, flags);
}