package org.farng.mp3.id3;
import java.io.IOException;
import java.io.RandomAccessFile;
import org.farng.mp3.InvalidTagException;
import org.farng.mp3.TagConstant;
import org.farng.mp3.TagUtility;
/**
* <p class=t> The extended header contains information that is not vital to the correct parsing of the tag information,
* hence the extended header is optional. </p>
* <p/>
* <p><center> <table border=0> <tr><td nowrap> Extended header size</td><td rowspan=3> </td><td width=100%>$xx xx
* xx xx</td></tr> <tr><td>Extended Flags</td><td>$xx xx</td></tr> <tr><td>Size of padding</td><td>$xx xx xx xx</tr>
* </table> </center>
* <p/>
* <p class=t> Where the 'Extended header size', currently 6 or 10 bytes, excludes itself. The 'Size of padding' is
* simply the total tag size excluding the frames and the headers, in other words the padding. The extended header is
* considered separate from the header proper, and as such is subject to unsynchronisation. </p>
* <p/>
* <p class=t> The extended flags are a secondary flag set which describes further attributes of the tag. These
* attributes are currently defined as follows </p>
* <p/>
* <p class=ind> %x0000000 00000000 </p>
* <p/>
* <p class=t> x - CRC data present </p>
* <p/>
* <p class=ind> If this flag is set four bytes of CRC-32 data is appended to the extended header. The CRC should be
* calculated before unsynchronisation on the data between the extended header and the padding, i.e. the frames and only
* the frames. </p>
* <p/>
* <p><center> <table border=0> <tr><td nowrap> Total frame CRC</td><td> </td><td>$xx xx xx xx</td></tr> </table>
* </center>
*
* @author Eric Farng
* @version $Revision: 2374 $
*/
public class ID3v2_3Frame extends ID3v2_2Frame {
protected boolean compression = false;
protected boolean encryption = false;
protected boolean fileAlterPreservation = false;
protected boolean groupingIdentity = false;
protected boolean readOnly = false; // @todo implement this read only!
// these are flags for each frame them selves
protected boolean tagAlterPreservation = false;
/**
* Creates a new ID3v2_3Frame object.
*/
public ID3v2_3Frame() {
setAlterPreservation();
}
/**
* Creates a new ID3v2_3Frame object.
*/
public ID3v2_3Frame(final AbstractID3v2FrameBody body) {
super(body);
setAlterPreservation();
}
/**
* Creates a new ID3v2_3Frame object.
*/
public ID3v2_3Frame(final ID3v2_3Frame copyObject) {
super(copyObject);
this.compression = copyObject.compression;
this.encryption = copyObject.encryption;
this.fileAlterPreservation = copyObject.fileAlterPreservation;
this.groupingIdentity = copyObject.groupingIdentity;
this.readOnly = copyObject.readOnly;
this.tagAlterPreservation = copyObject.tagAlterPreservation;
}
/**
* Creates a new ID3v2_3Frame object.
*/
public ID3v2_3Frame(final boolean readOnly,
final boolean groupingIdentity,
final boolean compression,
final boolean encryption,
final AbstractID3v2FrameBody body) {
super(body);
this.readOnly = readOnly;
this.groupingIdentity = groupingIdentity;
this.compression = compression;
this.encryption = encryption;
setAlterPreservation();
}
/**
* Creates a new ID3v2_4Frame object.
*/
public ID3v2_3Frame(final AbstractID3v2Frame frame) {
if (frame instanceof ID3v2_3Frame) {
final ID3v2_3Frame f = (ID3v2_3Frame) frame;
this.tagAlterPreservation = f.tagAlterPreservation;
this.fileAlterPreservation = f.fileAlterPreservation;
this.readOnly = f.readOnly;
this.groupingIdentity = f.groupingIdentity;
this.compression = f.compression;
this.encryption = f.encryption;
}
if (frame instanceof ID3v2_2Frame) {
// no variables yet
}
if (frame.getBody() == null) {
// do nothing
} else if (TagUtility.isID3v2_3FrameIdentifier(frame.getIdentifier())) {
this.setBody((AbstractID3v2FrameBody) TagUtility.copyObject(frame.getBody()));
// } else if (TagUtility.isID3v2_4FrameIdentifier(frame.getIdentifier())) {
// // @TODO correctly convert tags
// this.setBody((AbstractID3v2FrameBody) TagUtility.copyObject(frame.getBody()));
// } else if (TagUtility.isID3v2_2FrameIdentifier(frame.getIdentifier())) {
// // @TODO correctly convert tags
// this.setBody((AbstractID3v2FrameBody) TagUtility.copyObject(frame.getBody()));
}
}
/**
* Creates a new ID3v2_3Frame object.
*/
public ID3v2_3Frame(final RandomAccessFile file) throws IOException, InvalidTagException {
this.read(file);
}
public int getSize() {
return this.getBody().getSize() + 4 + 2 + 4;
}
public boolean equals(final Object obj) {
if ((obj instanceof ID3v2_3Frame) == false) {
return false;
}
final ID3v2_3Frame id3v2_3Frame = (ID3v2_3Frame) obj;
if (this.compression != id3v2_3Frame.compression) {
return false;
}
if (this.encryption != id3v2_3Frame.encryption) {
return false;
}
if (this.fileAlterPreservation != id3v2_3Frame.fileAlterPreservation) {
return false;
}
if (this.groupingIdentity != id3v2_3Frame.groupingIdentity) {
return false;
}
if (this.readOnly != id3v2_3Frame.readOnly) {
return false;
}
if (this.tagAlterPreservation != id3v2_3Frame.tagAlterPreservation) {
return false;
}
return super.equals(obj);
}
public void read(final RandomAccessFile file) throws IOException, InvalidTagException {
byte b;
long filePointer;
final byte[] buffer = new byte[4];
// lets scan for a non-zero byte;
do {
filePointer = file.getFilePointer();
b = file.readByte();
org.farng.mp3.id3.AbstractID3v2.incrementPaddingCounter();
} while (b == 0);
file.seek(filePointer);
org.farng.mp3.id3.AbstractID3v2.decrementPaddingCounter();
// read the four character identifier
file.read(buffer, 0, 4);
final String identifier = new String(buffer, 0, 4);
// is this a valid identifier?
if (isValidID3v2FrameIdentifier(identifier) == false) {
file.seek(file.getFilePointer() - 3);
throw new InvalidTagException(identifier + " is not a valid ID3v2.30 frame");
}
filePointer = file.getFilePointer();
// skip the 4 byte size
file.skipBytes(4);
// read the flag bytes
file.read(buffer, 0, 2);
this.tagAlterPreservation = (buffer[0] & TagConstant.MASK_V23_TAG_ALTER_PRESERVATION) != 0;
this.fileAlterPreservation = (buffer[0] & TagConstant.MASK_V23_FILE_ALTER_PRESERVATION) != 0;
this.readOnly = (buffer[0] & TagConstant.MASK_V23_READ_ONLY) != 0;
this.compression = (buffer[1] & TagConstant.MASK_V23_COMPRESSION) != 0;
this.encryption = (buffer[1] & TagConstant.MASK_V23_ENCRYPTION) != 0;
this.groupingIdentity = (buffer[1] & TagConstant.MASK_V23_GROUPING_IDENTITY) != 0;
file.seek(filePointer);
this.setBody(readBody(identifier, file));
}
public void write(final RandomAccessFile file) throws IOException {
final long filePointer;
final byte[] buffer = new byte[4];
final String str = TagUtility.truncate(getIdentifier(), 4);
for (int i = 0; i < str.length(); i++) {
buffer[i] = (byte) str.charAt(i);
}
file.write(buffer, 0, str.length());
filePointer = file.getFilePointer();
// skip the size bytes
file.skipBytes(4);
setAlterPreservation();
buffer[0] = 0;
buffer[1] = 0;
if (this.tagAlterPreservation) {
buffer[0] |= TagConstant.MASK_V23_TAG_ALTER_PRESERVATION;
}
if (this.fileAlterPreservation) {
buffer[0] |= TagConstant.MASK_V23_FILE_ALTER_PRESERVATION;
}
if (this.readOnly) {
buffer[0] |= TagConstant.MASK_V23_READ_ONLY;
}
if (this.compression) {
buffer[1] |= TagConstant.MASK_V23_COMPRESSION;
}
if (this.encryption) {
buffer[1] |= TagConstant.MASK_V23_ENCRYPTION;
}
if (this.groupingIdentity) {
buffer[1] |= TagConstant.MASK_V23_GROUPING_IDENTITY;
}
file.write(buffer, 0, 2);
file.seek(filePointer);
this.getBody().write(file);
}
protected void setAlterPreservation() {
final String str = getIdentifier();
if (str.equals("ETCO") ||
str.equals("EQUA") ||
str.equals("MLLT") ||
str.equals("POSS") ||
str.equals("SYLT") ||
str.equals("SYTC") ||
str.equals("RVAD") ||
str.equals("TENC") ||
str.equals("TLEN") ||
str.equals("TSIZ")) {
this.tagAlterPreservation = false;
this.fileAlterPreservation = true;
} else {
this.tagAlterPreservation = false;
this.fileAlterPreservation = true;
}
}
}