plibreader/src/ASF.php

<?php
/**
 * PHP Reader Library
 *
 * Copyright (c) 2006-2008 The PHP Reader Project Workgroup. All rights
 * reserved.
 * 
 * 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 project workgroup 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 ASF
 * @copyright  Copyright (c) 2006-2008 The PHP Reader Project Workgroup
 * @license    http://code.google.com/p/php-reader/wiki/License New BSD License
 * @version    $Id$
 */

/**#@+ @ignore */
require_once("Reader.php");
require_once("ASF/Object/Container.php");
/**#@-*/

/**
 * This class represents a file in Advanced Systems Format (ASF) as described in
 * {@link http://go.microsoft.com/fwlink/?LinkId=31334 The Advanced Systems
 * Format (ASF) Specification}. It is a file format that can contain various
 * types of information ranging from audio and video to script commands and
 * developer defined custom streams.
 *
 * The ASF file consists of code blocks that are called content objects. Each
 * of these objects have a format of their own. They may contain other objects
 * or other specific data. Each supported object has been implemented as their
 * own classes to ease the correct use of the information.
 * 
 * @package    php-reader
 * @subpackage ASF
 * @author     Sven Vollbehr <svollbehr@gmail.com>
 * @copyright  Copyright (c) 2006-2008 The PHP Reader Project Workgroup
 * @license    http://code.google.com/p/php-reader/wiki/License New BSD License
 * @version    $Rev$
 */
class ASF extends ASF_Object_Container
{
  const HEADER = "75b22630-668e-11cf-a6d9-00aa0062ce6c";
  const DATA = "75b22636-668e-11cf-a6d9-00aa0062ce6c";
  const SIMPLE_INDEX = "33000890-e5b1-11cf-89f4-00a0c90349cb";
  const INDEX = "d6e229d3-35da-11d1-9034-00a0c90349be";
  const MEDIA_OBJECT_INDEX = "feb103f8-12ad-4c64-840f-2a1d2f7ad48c";
  const TIMECODE_INDEX = "3cb73fd0-0c4a-4803-953d-edf7b6228f0c";
  
  /** @var string */
  private $_filename;
  
  /**
   * Constructs the ASF class with given file and options.
   *
   * The following options are currently recognized:
   *   o encoding -- Indicates the encoding that all the texts are presented
   *     with. By default this is set to utf-8. See the documentation of iconv
   *     for accepted values.
   *   o readonly -- Indicates that the file is read from a temporary location
   *     or another source it cannot be written back to.
   *
   * @param string $filename The path to the file or file descriptor of an
   *                         opened file.
   * @param Array  $options  The options array.
   */
  public function __construct($filename, $options = array())
  {
    $this->_reader = new Reader($this->_filename = $filename);
    $this->setOptions($options);
    if ($this->getOption("encoding", false) === false)
      $this->setOption("encoding", "utf-8");
    $this->setOffset(0);
    $this->setSize($this->_reader->getSize());
    $this->constructObjects
      (array
       (self::HEADER => "Header",
        self::DATA => "Data",
        self::SIMPLE_INDEX => "SimpleIndex",
        self::INDEX => "Index",
        self::MEDIA_OBJECT_INDEX => "MediaObjectIndex",
        self::TIMECODE_INDEX => "TimecodeIndex"));
  }
  
  /**
   * Returns the mandatory header object contained in this file.
   * 
   * @return ASF_Object_Header
   */
  public function getHeader()
  {
    $header = $this->getObjectsByIdentifier(self::HEADER);
    return $header[0];
  }
  
  /**
   * Returns the mandatory data object contained in this file.
   * 
   * @return ASF_Object_Data
   */
  public function getData()
  {
    $data = $this->getObjectsByIdentifier(self::DATA);
    return $data[0];
  }
  
  /**
   * Returns an array of index objects contained in this file.
   * 
   * @return Array
   */
  public function getIndices()
  {
    return $this->getObjectsByIdentifier
      (self::SIMPLE_INDEX . "|" . self::INDEX . "|" .
       self::MEDIA_OBJECT_INDEX . "|" . self::TIMECODE_INDEX);
  }
  
  /**
   * Writes the changes back to the original media file.
   *
   * Please note: currently the method writes only Content Description and
   * Extended Content Description Objects.
   */
  public function write()
  {
    throw new ASF_Exception("Not yet supported");
  }
}