1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
|
<?php
/**
* PHP Reader Library
*
* Copyright (c) 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 ISO 14496
* @copyright Copyright (c) 2008 The PHP Reader Project Workgroup
* @license http://code.google.com/p/php-reader/wiki/License New BSD License
* @version $Id: ILOC.php 92 2008-05-10 13:43:14Z svollbehr $
*/
/**#@+ @ignore */
require_once("ISO14496/Box.php");
/**#@-*/
/**
* The <i>The Item Location Box</i> provides a directory of resources in this or
* other files, by locating their containing file, their offset within that
* file, and their length. Placing this in binary format enables common handling
* of this data, even by systems which do not understand the particular metadata
* system (handler) used. For example, a system might integrate all the
* externally referenced metadata resources into one file, re-adjusting file
* offsets and file references accordingly.
*
* Items may be stored fragmented into extents, e.g. to enable interleaving. An
* extent is a contiguous subset of the bytes of the resource; the resource is
* formed by concatenating the extents. If only one extent is used then either
* or both of the offset and length may be implied:
*
* o If the offset is not identified (the field has a length of zero), then
* the beginning of the file (offset 0) is implied.
* o If the length is not specified, or specified as zero, then the entire
* file length is implied. References into the same file as this metadata,
* or items divided into more than one extent, should have an explicit
* offset and length, or use a MIME type requiring a different
* interpretation of the file, to avoid infinite recursion.
*
* The size of the item is the sum of the extentLengths. Note: extents may be
* interleaved with the chunks defined by the sample tables of tracks.
*
* The dataReferenceIndex may take the value 0, indicating a reference into the
* same file as this metadata, or an index into the dataReference table.
*
* Some referenced data may itself use offset/length techniques to address
* resources within it (e.g. an MP4 file might be included in this way).
* Normally such offsets are relative to the beginning of the containing file.
* The field base offset provides an additional offset for offset calculations
* within that contained data. For example, if an MP4 file is included within a
* file formatted to this specification, then normally data-offsets within that
* MP4 section are relative to the beginning of file; baseOffset adds to those
* offsets.
*
* @package php-reader
* @subpackage ISO 14496
* @author Sven Vollbehr <svollbehr@gmail.com>
* @copyright Copyright (c) 2008 The PHP Reader Project Workgroup
* @license http://code.google.com/p/php-reader/wiki/License New BSD License
* @version $Rev: 92 $
*/
final class ISO14496_Box_ILOC extends ISO14496_Box
{
/** @var Array */
private $_items = array();
/**
* Constructs the class with given parameters and reads box related data from
* the ISO Base Media file.
*
* @param Reader $reader The reader object.
*/
public function __construct($reader, &$options = array())
{
parent::__construct($reader, $options);
$offsetSize = (($tmp = $this->_reader->readUInt32BE()) >> 28) & 0xf;
$lengthSize = ($tmp >> 24) & 0xf;
$baseOffsetSize = ($tmp >> 20) & 0xf;
$itemCount = $this->_reader->readUInt16BE();
for ($i = 0; $i < $itemCount; $i++) {
$item = array();
$item["itemId"] = $this->_reader->readUInt16BE();
$item["dataReferenceIndex"] = $this->_reader->readUInt16BE();
$item["baseOffset"] =
($baseOffsetSize == 4 ? $this->_reader->readUInt32BE() :
($baseOffsetSize == 8 ? $this->_reader->readInt64BE() : 0));
$item["extents"] = array();
for ($j = 0; $j < $extentCount; $j++) {
$extent = array();
$extent["offset"] =
($offsetSize == 4 ? $this->_reader->readUInt32BE() :
($offsetSize == 8 ? $this->_reader->readInt64BE() : 0));
$extent["length"] =
($lengthSize == 4 ? $this->_reader->readUInt32BE() :
($lengthSize == 8 ? $this->_reader->readInt64BE() : 0));
$item["extents"][] = $extent;
}
$this->_items[] = $item;
}
}
/**
* Returns the array of items. Each entry has the following keys set: itemId,
* dataReferenceIndex, baseOffset, and extents.
*
* @return Array
*/
public function getItems() { return $this->_items; }
}
|
