ILIAS  release_5-2 Revision v5.2.25-18-g3f80b828510
Gif.php
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1<?php
2
3namespace GetId3\Module\Graphic;
4
5use GetId3\Handler\BaseHandler;
6use GetId3\Lib\Helper;
7
10// available at http://getid3.sourceforge.net //
11// or http://www.getid3.org //
13// See readme.txt for more details //
15// //
16// module.graphic.gif.php //
17// module for analyzing GIF Image files //
18// dependencies: NONE //
19// ///
21
29class Gif extends BaseHandler
30{
31
36 public function analyze()
37 {
38 $info = &$this->getid3->info;
39
40 $info['fileformat'] = 'gif';
41 $info['video']['dataformat'] = 'gif';
42 $info['video']['lossless'] = true;
43 $info['video']['pixel_aspect_ratio'] = (float) 1;
44
45 fseek($this->getid3->fp, $info['avdataoffset'], SEEK_SET);
46 $GIFheader = fread($this->getid3->fp, 13);
47 $offset = 0;
48
49 $info['gif']['header']['raw']['identifier'] = substr($GIFheader, $offset, 3);
50 $offset += 3;
51
52 $magic = 'GIF';
53 if ($info['gif']['header']['raw']['identifier'] != $magic) {
54 $info['error'][] = 'Expecting "'.Helper::PrintHexBytes($magic).'" at offset '.$info['avdataoffset'].', found "'.Helper::PrintHexBytes($info['gif']['header']['raw']['identifier']).'"';
55 unset($info['fileformat']);
56 unset($info['gif']);
57
58 return false;
59 }
60
61 $info['gif']['header']['raw']['version'] = substr($GIFheader, $offset, 3);
62 $offset += 3;
63 $info['gif']['header']['raw']['width'] = Helper::LittleEndian2Int(substr($GIFheader, $offset, 2));
64 $offset += 2;
65 $info['gif']['header']['raw']['height'] = Helper::LittleEndian2Int(substr($GIFheader, $offset, 2));
66 $offset += 2;
67 $info['gif']['header']['raw']['flags'] = Helper::LittleEndian2Int(substr($GIFheader, $offset, 1));
68 $offset += 1;
69 $info['gif']['header']['raw']['bg_color_index'] = Helper::LittleEndian2Int(substr($GIFheader, $offset, 1));
70 $offset += 1;
71 $info['gif']['header']['raw']['aspect_ratio'] = Helper::LittleEndian2Int(substr($GIFheader, $offset, 1));
72 $offset += 1;
73
74 $info['video']['resolution_x'] = $info['gif']['header']['raw']['width'];
75 $info['video']['resolution_y'] = $info['gif']['header']['raw']['height'];
76 $info['gif']['version'] = $info['gif']['header']['raw']['version'];
77 $info['gif']['header']['flags']['global_color_table'] = (bool) ($info['gif']['header']['raw']['flags'] & 0x80);
78 if ($info['gif']['header']['raw']['flags'] & 0x80) {
79 // Number of bits per primary color available to the original image, minus 1
80 $info['gif']['header']['bits_per_pixel'] = 3 * ((($info['gif']['header']['raw']['flags'] & 0x70) >> 4) + 1);
81 } else {
82 $info['gif']['header']['bits_per_pixel'] = 0;
83 }
84 $info['gif']['header']['flags']['global_color_sorted'] = (bool) ($info['gif']['header']['raw']['flags'] & 0x40);
85 if ($info['gif']['header']['flags']['global_color_table']) {
86 // the number of bytes contained in the Global Color Table. To determine that
87 // actual size of the color table, raise 2 to [the value of the field + 1]
88 $info['gif']['header']['global_color_size'] = pow(2, ($info['gif']['header']['raw']['flags'] & 0x07) + 1);
89 $info['video']['bits_per_sample'] = ($info['gif']['header']['raw']['flags'] & 0x07) + 1;
90 } else {
91 $info['gif']['header']['global_color_size'] = 0;
92 }
93 if ($info['gif']['header']['raw']['aspect_ratio'] != 0) {
94 // Aspect Ratio = (Pixel Aspect Ratio + 15) / 64
95 $info['gif']['header']['aspect_ratio'] = ($info['gif']['header']['raw']['aspect_ratio'] + 15) / 64;
96 }
97
98// if ($info['gif']['header']['flags']['global_color_table']) {
99// $GIFcolorTable = fread($this->getid3->fp, 3 * $info['gif']['header']['global_color_size']);
100// $offset = 0;
101// for ($i = 0; $i < $info['gif']['header']['global_color_size']; $i++) {
102// $red = GetId3_lib::LittleEndian2Int(substr($GIFcolorTable, $offset++, 1));
103// $green = GetId3_lib::LittleEndian2Int(substr($GIFcolorTable, $offset++, 1));
104// $blue = GetId3_lib::LittleEndian2Int(substr($GIFcolorTable, $offset++, 1));
105// $info['gif']['global_color_table'][$i] = (($red << 16) | ($green << 8) | ($blue));
106// }
107// }
108//
109// // Image Descriptor
110// while (!feof($this->getid3->fp)) {
111// $NextBlockTest = fread($this->getid3->fp, 1);
112// switch ($NextBlockTest) {
113//
114// case ',': // ',' - Image separator character
115//
116// $ImageDescriptorData = $NextBlockTest.fread($this->getid3->fp, 9);
117// $ImageDescriptor = array();
118// $ImageDescriptor['image_left'] = GetId3_lib::LittleEndian2Int(substr($ImageDescriptorData, 1, 2));
119// $ImageDescriptor['image_top'] = GetId3_lib::LittleEndian2Int(substr($ImageDescriptorData, 3, 2));
120// $ImageDescriptor['image_width'] = GetId3_lib::LittleEndian2Int(substr($ImageDescriptorData, 5, 2));
121// $ImageDescriptor['image_height'] = GetId3_lib::LittleEndian2Int(substr($ImageDescriptorData, 7, 2));
122// $ImageDescriptor['flags_raw'] = GetId3_lib::LittleEndian2Int(substr($ImageDescriptorData, 9, 1));
123// $ImageDescriptor['flags']['use_local_color_map'] = (bool) ($ImageDescriptor['flags_raw'] & 0x80);
124// $ImageDescriptor['flags']['image_interlaced'] = (bool) ($ImageDescriptor['flags_raw'] & 0x40);
125// $info['gif']['image_descriptor'][] = $ImageDescriptor;
126//
127// if ($ImageDescriptor['flags']['use_local_color_map']) {
128//
129// $info['warning'][] = 'This version of GetId3Core() cannot parse local color maps for GIFs';
130// return true;
131//
132// }
133//echo 'Start of raster data: '.ftell($this->getid3->fp).'<BR>';
134// $RasterData = array();
135// $RasterData['code_size'] = GetId3_lib::LittleEndian2Int(fread($this->getid3->fp, 1));
136// $RasterData['block_byte_count'] = GetId3_lib::LittleEndian2Int(fread($this->getid3->fp, 1));
137// $info['gif']['raster_data'][count($info['gif']['image_descriptor']) - 1] = $RasterData;
138//
139// $CurrentCodeSize = $RasterData['code_size'] + 1;
140// for ($i = 0; $i < pow(2, $RasterData['code_size']); $i++) {
141// $DefaultDataLookupTable[$i] = chr($i);
142// }
143// $DefaultDataLookupTable[pow(2, $RasterData['code_size']) + 0] = ''; // Clear Code
144// $DefaultDataLookupTable[pow(2, $RasterData['code_size']) + 1] = ''; // End Of Image Code
145//
146//
147// $NextValue = $this->GetLSBits($CurrentCodeSize);
148// echo 'Clear Code: '.$NextValue.'<BR>';
149//
150// $NextValue = $this->GetLSBits($CurrentCodeSize);
151// echo 'First Color: '.$NextValue.'<BR>';
152//
153// $Prefix = $NextValue;
154//$i = 0;
155// while ($i++ < 20) {
156// $NextValue = $this->GetLSBits($CurrentCodeSize);
157// echo $NextValue.'<BR>';
158// }
159//return true;
160// break;
161//
162// case '!':
163// // GIF Extension Block
164// $ExtensionBlockData = $NextBlockTest.fread($this->getid3->fp, 2);
165// $ExtensionBlock = array();
166// $ExtensionBlock['function_code'] = GetId3_lib::LittleEndian2Int(substr($ExtensionBlockData, 1, 1));
167// $ExtensionBlock['byte_length'] = GetId3_lib::LittleEndian2Int(substr($ExtensionBlockData, 2, 1));
168// $ExtensionBlock['data'] = fread($this->getid3->fp, $ExtensionBlock['byte_length']);
169// $info['gif']['extension_blocks'][] = $ExtensionBlock;
170// break;
171//
172// case ';':
173// $info['gif']['terminator_offset'] = ftell($this->getid3->fp) - 1;
174// // GIF Terminator
175// break;
176//
177// default:
178// break;
179//
180//
181// }
182// }
183 return true;
184 }
185
192 public function GetLSBits($bits)
193 {
194 static $bitbuffer = '';
195 while (strlen($bitbuffer) < $bits) {
196 $bitbuffer = str_pad(decbin(ord(fread($this->getid3->fp, 1))), 8, '0', STR_PAD_LEFT).$bitbuffer;
197 }
198 $value = bindec(substr($bitbuffer, 0 - $bits));
199 $bitbuffer = substr($bitbuffer, 0, 0 - $bits);
200
201 return $value;
202 }
203
204}
php
An exception for terminatinating execution or to throw for unit testing.
GetId3\Handler\BaseHandler
GetId3() by James Heinrich info@getid3.org //.
Definition: BaseHandler.php:26
GetId3\Handler\BaseHandler\fseek
fseek($bytes, $whence=SEEK_SET)
Definition: BaseHandler.php:148
GetId3\Lib\Helper
GetId3() by James Heinrich info@getid3.org //.
Definition: Helper.php:27
GetId3\Lib\Helper\LittleEndian2Int
static LittleEndian2Int($byteword, $signed=false)
Definition: Helper.php:413
GetId3\Lib\Helper\PrintHexBytes
static PrintHexBytes($string, $hex=true, $spaces=true, $htmlencoding='UTF-8')
Definition: Helper.php:36
GetId3\Module\Graphic\Gif
GetId3() by James Heinrich info@getid3.org //.
Definition: Gif.php:30
GetId3\Module\Graphic\Gif\GetLSBits
GetLSBits($bits)
@staticvar string $bitbuffer
Definition: Gif.php:192
$info
$info
Definition: example_052.php:80