Add support for ID3v2.4

git-svn-id: http://php-reader.googlecode.com/svn/trunk@11 51a70ab9-7547-0410-9469-37e369ee0574
2008-03-12 12:06:41 +00:00
parent afdfc67582
commit 165d162582
93 changed files with 7630 additions and 0 deletions
--- a/src/ID3/Frame/ASPI.php
+++ b/src/ID3/Frame/ASPI.php
@@ -0,0 +1,125 @@
+<?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("ID3/Frame.php");
+/**#@-*/
+
+/**
+ * Audio files with variable bit rates are intrinsically difficult to deal with
+ * in the case of seeking within the file. The <i>Audio seek point index</i> or
+ * ASPI frame makes seeking easier by providing a list a seek points within the
+ * audio file. The seek points are a fractional offset within the audio data,
+ * providing a starting point from which to find an appropriate point to start
+ * decoding. The presence of an ASPI frame requires the existence of a
+ * {@link ID3_Frame_TLEN} frame, indicating the duration of the file in
+ * milliseconds. There may only be one audio seek point index frame in a tag.
+ * 
+ * @package    php-reader
+ * @subpackage ID3
+ * @author     Sven Vollbehr <sven.vollbehr@behrss.eu>
+ * @copyright  Copyright (c) 2008 BEHR Software Systems
+ * @license    http://www.opensource.org/licenses/bsd-license.php New BSD License
+ * @version    $Rev$
+ */
+final class ID3_Frame_ASPI extends ID3_Frame
+{
+  /** @var integer */
+  private $_dataStart;
+  
+  /** @var integer */
+  private $_dataLength;
+  
+  /** @var integer */
+  private $_size;
+  
+  /** @var Array */
+  private $_fraction = array();
+  
+  /**
+   * Constructs the class with given parameters and parses object related data.
+   *
+   * @param Reader $reader The reader object.
+   */
+  public function __construct($reader)
+  {
+    parent::__construct($reader);
+
+    $this->_dataStart = Transform::getInt32BE(substr($this->_data, 0, 4));
+    $this->_dataLength = Transform::getInt32BE(substr($this->_data, 4, 4));
+    $this->_size = Transform::getInt16BE(substr($this->_data, 8, 2));
+    $bitsPerPoint = substr($this->_data, 10, 1);
+    for ($i = 0, $offset = 11; $i < $this->_size; $i++) {
+      if ($bitsPerPoint == 16) {
+        $this->_fraction[$i] = substr($this->_data, $offset, 2);
+        $offset += 2;
+      } else {
+        $this->_fraction[$i] = substr($this->_data, $offset, 1);
+        $offset ++;
+      }
+    }
+  }
+
+  /**
+   * Returns the byte offset from the beginning of the file.
+   * 
+   * @return integer
+   */
+  public function getDataStart() { return $this->_dataStart; }
+
+  /**
+   * Returns the byte length of the audio data being indexed.
+   * 
+   * @return integer
+   */
+  public function getDataLength() { return $this->_dataLength; }
+
+  /**
+   * Returns the number of index points in the frame.
+   * 
+   * @return integer
+   */
+  public function getSize() { return $this->_size; }
+
+  /**
+   * Returns the numerator of the fraction representing a relative position in
+   * the data or <var>false</var> if index not defined. The denominator is 2
+   * to the power of b.
+   * 
+   * @param integer $index The fraction numerator.
+   * @return integer
+   */
+  public function getFractionAt($index) { return $this->_fraction[$index]; }
+}