/*
* Entagged Audio Tag library
* Copyright (c) 2003-2005 Raphaël Slinckx <raphael@slinckx.net>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
package org.jaudiotagger.tag.mp4;
import org.jaudiotagger.audio.generic.Utils;
import org.jaudiotagger.audio.mp4.atom.Mp4BoxHeader;
import org.jaudiotagger.tag.TagField;
import org.jaudiotagger.tag.mp4.atom.Mp4DataBox;
import org.jaudiotagger.tag.mp4.field.Mp4FieldType;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.nio.ByteBuffer;
import java.util.logging.Logger;
/**
* This abstract class represents a link between piece of data, and how it is stored as an mp4 atom
* <p/>
* Note there isnt a one to one correspondance between a tag field and a box because some fields are represented
* by multiple boxes, for example many of the MusicBrainz fields use the '----' box, which in turn uses one of mean,
* name and data box. So an instance of a tag field maps to one item of data such as 'Title', but it may have to read
* multiple boxes to do this.
* <p/>
* There are various subclasses that represent different types of fields
*/
public abstract class Mp4TagField implements TagField {
// Logger Object
public static Logger logger = Logger.getLogger("org.jaudiotagger.tag.mp4");
protected String id;
//Just used by reverese dns class, so it knows the size of its aprent so it can detect end correctly
protected Mp4BoxHeader parentHeader;
protected Mp4TagField(String id) {
this.id = id;
}
/**
* Used by subclasses that canot identify their id until after they have been built such as ReverseDnsField
*
* @param data
* @throws UnsupportedEncodingException
*/
protected Mp4TagField(ByteBuffer data) throws UnsupportedEncodingException {
build(data);
}
/**
* Used by reverese dns when reading from file, so can identify when there is a data atom
*
* @param parentHeader
* @param data
* @throws UnsupportedEncodingException
*/
protected Mp4TagField(Mp4BoxHeader parentHeader, ByteBuffer data) throws UnsupportedEncodingException {
this.parentHeader = parentHeader;
build(data);
}
protected Mp4TagField(String id, ByteBuffer data) throws UnsupportedEncodingException {
this(id);
build(data);
}
/**
* @return field identifier
*/
public String getId() {
return id;
}
public void isBinary(boolean b) {
/* One cannot choose if an arbitrary block can be binary or not */
}
public boolean isCommon() {
return id.equals(Mp4FieldKey.ARTIST.getFieldName()) || id.equals(Mp4FieldKey.ALBUM.getFieldName()) || id.equals(Mp4FieldKey.TITLE.getFieldName()) || id.equals(Mp4FieldKey.TRACK.getFieldName()) || id.equals(Mp4FieldKey.DAY.getFieldName()) || id.equals(Mp4FieldKey.COMMENT.getFieldName()) || id.equals(Mp4FieldKey.GENRE.getFieldName());
}
/**
* @return field identifier as it will be held within the file
*/
protected byte[] getIdBytes() {
return Utils.getDefaultBytes(getId(), "ISO-8859-1");
}
/**
* @return the data as it is held on file
* @throws UnsupportedEncodingException
*/
protected abstract byte[] getDataBytes() throws UnsupportedEncodingException;
/**
* @return the field type of this field
*/
public abstract Mp4FieldType getFieldType();
/**
* Processes the data and sets the position of the data buffer to just after the end of this fields data
* ready for processing next field.
*
* @param data
* @throws UnsupportedEncodingException
*/
protected abstract void build(ByteBuffer data) throws UnsupportedEncodingException;
/**
* Convert back to raw content, includes parent and data atom as views as one thing externally
*
* @return
* @throws UnsupportedEncodingException
*/
public byte[] getRawContent() throws UnsupportedEncodingException {
//logger.fine("Getting Raw data for:" + getId());
try {
//Create Data Box
byte[] databox = getRawContentDataOnly();
//Wrap in Parent box
ByteArrayOutputStream outerbaos = new ByteArrayOutputStream();
outerbaos.write(Utils.getSizeBEInt32(Mp4BoxHeader.HEADER_LENGTH + databox.length));
outerbaos.write(Utils.getDefaultBytes(getId(), "ISO-8859-1"));
outerbaos.write(databox);
return outerbaos.toByteArray();
} catch (IOException ioe) {
//This should never happen as were not actually writing to/from a file
throw new RuntimeException(ioe);
}
}
/**
* Get raw content for the data component only
*
* @return
* @throws UnsupportedEncodingException
*/
public byte[] getRawContentDataOnly() throws UnsupportedEncodingException {
//logger.fine("Getting Raw data for:" + getId());
try {
//Create Data Box
ByteArrayOutputStream baos = new ByteArrayOutputStream();
byte[] data = getDataBytes();
baos.write(Utils.getSizeBEInt32(Mp4DataBox.DATA_HEADER_LENGTH + data.length));
baos.write(Utils.getDefaultBytes(Mp4DataBox.IDENTIFIER, "ISO-8859-1"));
baos.write(new byte[]{0});
baos.write(new byte[]{0, 0, (byte) getFieldType().getFileClassId()});
baos.write(new byte[]{0, 0, 0, 0});
baos.write(data);
return baos.toByteArray();
} catch (IOException ioe) {
//This should never happen as were not actually writing to/from a file
throw new RuntimeException(ioe);
}
}
}