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A port of the Free Lossless Audio Codec (FLAC) decoder to Java and a FLAC encoder implemented in Java.

There is a newer version: 1.4.1

/*
 * Copyright (C) 2010  Preston Lacey http://javaflacencoder.sourceforge.net/
 * All Rights Reserved.
 *
 * 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 Street, Fifth Floor, Boston, MA  02110-1301  USA
 */

package net.sourceforge.javaflacencoder;

/**
 * The MetadataBlockHeader class is used to creat FLAC compliant Metadata Block
 * Headers. See the FLAC specification for more information.
 *
 * @author Preston Lacey
 */
public class MetadataBlockHeader {
    
  //boolean lastMetadataBlockFlag;//1 bit used
  //byte blockType;//7 bits used
  //int length;//24 bits used

  /**
   * Enum containing the different Metadata block types. See the FLAC spec
   * for more information on the various types.
   */
  public enum MetadataBlockType {
    /** A meta-block containing stream configuration information */
    STREAMINFO,
    /** A meta-block to pad the stream, allowing other meta-data to be
     * written in the future without re-writing the entire stream.
     */
    PADDING,
    /** Application meta-block*/
    APPLICATION,
    /** A meta-block which aids in seeking in the stream */
    SEEKTABLE,
    /** A meta-block for tags/comments */
    VORBIS_COMMENT,
    /** Cuesheet meta-block */
    CUESHEET,
    /** A meta-block to store an image, such as cover-art */
    PICTURE
  };

  /**
   * Constructor. This class defines no instance variables and only static
   * methods.
   */
  public MetadataBlockHeader() {

  }


  /**
   * Create a meta-data block header of the given type, and return the result
   * in a new EncodedElement(so data is ready to be placed directly in FLAC
   * stream)
   *
   * @param lastBlock True if this is the last meta-block in the stream. False
   * otherwise.
   *
   * @param type enum indicating which type of block we're creating.
   * @param length Length of the meta-data block which follows this header.
   * @return EncodedElement containing the header.
   */
  public static EncodedElement getMetadataBlockHeader(boolean lastBlock,
      MetadataBlockType type, int length) {
    EncodedElement ele = new EncodedElement(4, 0);
    int encodedLastBlock = (lastBlock) ? 1:0;
    ele.addInt(encodedLastBlock, 1);
    int encodedType = 0;
    MetadataBlockType[] vals = MetadataBlockType.values();
    for(int i = 0; i < vals.length; i++) {
      if(vals[i] == type) {
        encodedType = i;
        break;
      }
    }

    ele.addInt(encodedType, 7);
    ele.addInt(length, 24);
    return ele;
  }
    
}