Add support for ID3v2.4

git-svn-id: http://php-reader.googlecode.com/svn/trunk@11 51a70ab9-7547-0410-9469-37e369ee0574

src/ID3/Frame.php

@@ -0,0 +1,170 @@
+<?php
+/**
+ * PHP Reader Library
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *  - Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *  - Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *  - Neither the name of the BEHR Software Systems nor the names of its
+ *    contributors may be used to endorse or promote products derived from this
+ *    software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * @package    php-reader
+ * @subpackage ID3
+ * @copyright  Copyright (c) 2008 BEHR Software Systems
+ * @license    http://www.opensource.org/licenses/bsd-license.php New BSD License
+ * @version    $Id$
+ */
+
+/**#@+ @ignore */
+require_once("Object.php");
+/**#@-*/
+
+/**
+ * A base class for all ID3v2 frames as described in the
+ * {@link http://www.id3.org/id3v2.4.0-frames ID3v2 frames document}.
+ *
+ * 
+ * @package    php-reader
+ * @subpackage ID3
+ * @author     Sven Vollbehr <sven.vollbehr@behrss.eu>
+ * @copyright  2008 BEHR Software Systems
+ * @license    http://www.opensource.org/licenses/bsd-license.php New BSD License
+ * @version    $Rev$
+ */
+class ID3_Frame extends ID3_Object
+{
+  /**
+   * This flag tells the tag parser what to do with this frame if it is unknown
+   * and the tag is altered in any way. This applies to all kinds of
+   * alterations, including adding more padding and reordering the frames.
+   */
+  const DISCARD_ON_TAGCHANGE = 16384;
+  
+  /**
+   * This flag tells the tag parser what to do with this frame if it is unknown
+   * and the file, excluding the tag, is altered. This does not apply when the
+   * audio is completely replaced with other audio data.
+   */
+  const DISCARD_ON_FILECHANGE = 8192;
+  
+  /**
+   * This flag, if set, tells the software that the contents of this frame are
+   * intended to be read only. Changing the contents might break something,
+   * e.g. a signature.
+   */
+  const READ_ONLY = 4096;
+  
+  /**
+   * This flag indicates whether or not this frame belongs in a group with
+   * other frames. If set, a group identifier byte is added to the frame. Every
+   * frame with the same group identifier belongs to the same group.
+   */
+  const GROUPING_IDENTITY = 32;
+  
+  /**
+   * This flag indicates whether or not the frame is compressed. A <i>Data
+   * Length Indicator</i> byte is included in the frame.
+   *
+   * @see DATA_LENGTH_INDICATOR
+   */
+  const COMPRESSION = 8;
+  
+  /**
+   * This flag indicates whether or not the frame is encrypted. If set, one byte
+   * indicating with which method it was encrypted will be added to the frame.
+   * See description of the {@link ID3_Frame_ENCR} frame for more information
+   * about encryption method registration. Encryption should be done after
+   * compression. Whether or not setting this flag requires the presence of a
+   * <i>Data Length Indicator</i> depends on the specific algorithm used.
+   *
+   * @see DATA_LENGTH_INDICATOR
+   */
+  const ENCRYPTION = 4;
+  
+  /**
+   * This flag indicates whether or not unsynchronisation was applied to this
+   * frame.
+   */
+  const UNSYNCHRONISATION = 2;
+  
+  /**
+   * This flag indicates that a data length indicator has been added to the
+   * frame.
+   */
+  const DATA_LENGTH_INDICATOR = 1;
+
+  /** @var integer */
+  private $_identifier;
+
+  /** @var integer */
+  private $_size;
+
+  /** @var integer */
+  private $_flags;
+  
+  /**
+   * Raw content read from the frame.
+   * 
+   * @var string
+   */
+  protected $_data;
+  
+  /**
+   * Constructs the class with given parameters and reads object related data
+   * from the ID3v2 tag.
+   *
+   * @todo  Only limited subset of flags are processed.
+   * @param Reader $reader The reader object.
+   */
+  public function __construct($reader)
+  {
+    parent::__construct($reader);
+
+    $this->_identifier = $this->_reader->getString8(4);
+    $this->_size = $this->decodeSynchsafe32($this->_reader->getUInt32BE());
+    $this->_flags = $this->_reader->getUInt16BE();
+    $this->_data = $this->_reader->read($this->_size);
+  }
+  
+  /**
+   * Returns the frame identifier string.
+   * 
+   * @return string
+   */
+  public function getIdentifier() { return $this->_identifier; }
+
+  /**
+   * Returns the size of the data in the final frame, after encryption,
+   * compression and unsynchronisation. The size is excluding the frame header.
+   * 
+   * @return integer
+   */
+  public function getSize() { return $this->_size; }
+
+  /**
+   * Checks whether or not the flag is set. Returns <var>true</var> if the flag
+   * is set, <var>false</var> otherwise.
+   * 
+   * @param integer $flag The flag to query.
+   * @return boolean
+   */
+  public function hasFlag($flag) { return ($this->_flags & $flag) == $flag; }
+}