/*

  * 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.audio.ogg;

 import org.jaudiotagger.audio.ogg.util.VorbisHeader;

 import org.jaudiotagger.audio.ogg.util.VorbisPacketType;

 import org.jaudiotagger.tag.Tag;

 import org.jaudiotagger.tag.vorbiscomment.VorbisCommentCreator;

 import java.io.UnsupportedEncodingException;

 import java.nio.ByteBuffer;

 import java.util.logging.Logger;

 /**

  * Creates an OggVorbis Comment Tag from a VorbisComment for use within an OggVorbis Container

  * <p/>

  * When a Vorbis Comment is used within OggVorbis it additionally has a vorbis header and a framing

  * bit.

  */

 public class OggVorbisCommentTagCreator

 {

     // Logger Object

     public static Logger logger = Logger.getLogger("org.jaudiotagger.audio.ogg");

     public static final int FIELD_FRAMING_BIT_LENGTH = 1;

     public static final byte FRAMING_BIT_VALID_VALUE = (byte) 0x01;

     private VorbisCommentCreator creator = new VorbisCommentCreator();

     //Creates the ByteBuffer for the ogg tag

     public ByteBuffer convert(Tag tag) throws UnsupportedEncodingException

     {

         ByteBuffer ogg = creator.convert(tag);

         int tagLength = ogg.capacity() + VorbisHeader.FIELD_PACKET_TYPE_LENGTH + VorbisHeader.FIELD_CAPTURE_PATTERN_LENGTH + OggVorbisCommentTagCreator.FIELD_FRAMING_BIT_LENGTH;

         ByteBuffer buf = ByteBuffer.allocate(tagLength);

         //[packet type=comment0x03]['vorbis']

         buf.put((byte) VorbisPacketType.COMMENT_HEADER.getType());

         buf.put(VorbisHeader.CAPTURE_PATTERN_AS_BYTES);

         //The actual tag

         buf.put(ogg);

         //Framing bit = 1

         buf.put(FRAMING_BIT_VALID_VALUE);

         buf.rewind();

         return buf;

     }

 }