Mercurial > judyates

     1 <?php

     2 // +----------------------------------------------------------------------+

     3 // | PHP version 5                                                        |

     4 // +----------------------------------------------------------------------+

     5 // | Copyright (c) 2002-2006 James Heinrich, Allan Hansen                 |

     6 // +----------------------------------------------------------------------+

     7 // | This source file is subject to version 2 of the GPL license,         |

     8 // | that is bundled with this package in the file license.txt and is     |

     9 // | available through the world-wide-web at the following url:           |

    10 // | http://www.gnu.org/copyleft/gpl.html                                 |

    11 // +----------------------------------------------------------------------+

    12 // | getID3() - http://getid3.sourceforge.net or http://www.getid3.org    |

    13 // +----------------------------------------------------------------------+

    14 // | Authors: James Heinrich <infoØgetid3*org>                            |

    15 // |          Allan Hansen <ahØartemis*dk>                                |

    16 // +----------------------------------------------------------------------+

    17 // | module.lib.data-hash.php                                             |

    18 // | getID3() library file.                                               |

    19 // | dependencies: NONE.                                                  |

    20 // +----------------------------------------------------------------------+

    21 //

    22 // $Id: module.lib.image_size.php,v 1.2 2006/11/02 10:48:02 ah Exp $

    23 

    24 

    25 

    26 class getid3_lib_image_size

    27 {

    28     

    29     const GIF_SIG   = "\x47\x49\x46";                           // 'GIF'

    30     const PNG_SIG   = "\x89\x50\x4E\x47\x0D\x0A\x1A\x0A";

    31     const JPG_SIG   = "\xFF\xD8\xFF";

    32     const JPG_SOS   = "\xDA";                                   // Start Of Scan - image data start

    33     const JPG_SOF0  = "\xC0";                                   // Start Of Frame N

    34     const JPG_SOF1  = "\xC1";                                   // N indicates which compression process

    35     const JPG_SOF2  = "\xC2";                                   // Only SOF0-SOF2 are now in common use

    36     const JPG_SOF3  = "\xC3";                                   // NB: codes C4 and CC are *not* SOF markers

    37     const JPG_SOF5  = "\xC5";                                   

    38     const JPG_SOF6  = "\xC6";                                   

    39     const JPG_SOF7  = "\xC7";                                   

    40     const JPG_SOF9  = "\xC9";                                   

    41     const JPG_SOF10 = "\xCA";                                   

    42     const JPG_SOF11 = "\xCB";                                   // NB: codes C4 and CC are *not* SOF markers

    43     const JPG_SOF13 = "\xCD";                                   

    44     const JPG_SOF14 = "\xCE";                                   

    45     const JPG_SOF15 = "\xCF";                                   

    46     const JPG_EOI   = "\xD9";                                   // End Of Image (end of datastream)

    47 

    48 

    49     static public function get($img_data) {

    50 

    51         $height = $width  = $type   = '';

    52         

    53         if ((substr($img_data, 0, 3) == getid3_lib_image_size::GIF_SIG) && (strlen($img_data) > 10)) {

    54             

    55             $dim = unpack('v2dim', substr($img_data, 6, 4));

    56             $width  = $dim['dim1'];

    57             $height = $dim['dim2'];

    58             $type = 1;

    59             

    60         } elseif ((substr($img_data, 0, 8) == getid3_lib_image_size::PNG_SIG) && (strlen($img_data) > 24)) {

    61             

    62             $dim = unpack('N2dim', substr($img_data, 16, 8));

    63             $width  = $dim['dim1'];

    64             $height = $dim['dim2'];

    65             $type = 3;

    66             

    67         } elseif ((substr($img_data, 0, 3) == getid3_lib_image_size::JPG_SIG) && (strlen($img_data) > 4)) {

    68             

    69             ///////////////// JPG CHUNK SCAN ////////////////////

    70             $img_pos = $type = 2;

    71             $buffer = strlen($img_data) - 2;

    72             while ($img_pos < strlen($img_data)) {

    73             

    74                 // synchronize to the marker 0xFF

    75                 $img_pos = strpos($img_data, 0xFF, $img_pos) + 1;

    76                 $marker = $img_data[$img_pos];

    77                 do {

    78                     $marker = ord($img_data[$img_pos++]);

    79                 } while ($marker == 255);

    80             

    81                 // find dimensions of block

    82                 switch (chr($marker)) {

    83             

    84                     // Grab width/height from SOF segment (these are acceptable chunk types)

    85                     case getid3_lib_image_size::JPG_SOF0:

    86                     case getid3_lib_image_size::JPG_SOF1:

    87                     case getid3_lib_image_size::JPG_SOF2:

    88                     case getid3_lib_image_size::JPG_SOF3:

    89                     case getid3_lib_image_size::JPG_SOF5:

    90                     case getid3_lib_image_size::JPG_SOF6:

    91                     case getid3_lib_image_size::JPG_SOF7:

    92                     case getid3_lib_image_size::JPG_SOF9:

    93                     case getid3_lib_image_size::JPG_SOF10:

    94                     case getid3_lib_image_size::JPG_SOF11:

    95                     case getid3_lib_image_size::JPG_SOF13:

    96                     case getid3_lib_image_size::JPG_SOF14:

    97                     case getid3_lib_image_size::JPG_SOF15:

    98                         $dim = unpack('n2dim', substr($img_data, $img_pos + 3, 4));

    99                         $height = $dim['dim1'];

   100                         $width  = $dim['dim2'];

   101                         break 2; // found it so exit

   102             

   103                     case getid3_lib_image_size::JPG_EOI:

   104                     case getid3_lib_image_size::JPG_SOS:

   105                         return false;      

   106             

   107                     default:   // We're not interested in other markers

   108                         $skiplen = (ord($img_data[$img_pos++]) << 8) + ord($img_data[$img_pos++]) - 2;

   109                         // if the skip is more than what we've read in, read more

   110                         $buffer -= $skiplen;

   111                         if ($buffer < 512) { // if the buffer of data is too low, read more file.

   112                             return false; 

   113                         }

   114                         $img_pos += $skiplen;

   115                         break;

   116                 } 

   117             } 

   118         } 

   119 

   120         return array ($width, $height, $type);

   121     } // end function

   122 

   123 

   124 }

   125 

   126 ?>
author	Robert McIntyre <rlm@mit.edu>
date	Tue, 22 Jun 2010 13:41:04 -0400
parents	3f6b44aa6b35
children