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<?php
/* vim:set tabstop=8 softtabstop=8 shiftwidth=8 noexpandtab: */
// +----------------------------------------------------------------------+
// | PHP version 5 |
// +----------------------------------------------------------------------+
// | Copyright (c) 2002-2006 James Heinrich, Allan Hansen |
// +----------------------------------------------------------------------+
// | This source file is subject to version 2 of the GPL license, |
// | that is bundled with this package in the file license.txt and is |
// | available through the world-wide-web at the following url: |
// | http://www.gnu.org/copyleft/gpl.html |
// +----------------------------------------------------------------------+
// | getID3() - http://getid3.sourceforge.net or http://www.getid3.org |
// +----------------------------------------------------------------------+
// | Authors: James Heinrich <info�getid3*org> |
// | Allan Hansen <ah�artemis*dk> |
// +----------------------------------------------------------------------+
// | module.lib.data-hash.php |
// | getID3() library file. |
// | dependencies: NONE. |
// +----------------------------------------------------------------------+
//
// $Id: module.lib.image_size.php,v 1.2 2006/11/02 10:48:02 ah Exp $
class getid3_lib_image_size
{
const GIF_SIG = "\x47\x49\x46"; // 'GIF'
const PNG_SIG = "\x89\x50\x4E\x47\x0D\x0A\x1A\x0A";
const JPG_SIG = "\xFF\xD8\xFF";
const JPG_SOS = "\xDA"; // Start Of Scan - image data start
const JPG_SOF0 = "\xC0"; // Start Of Frame N
const JPG_SOF1 = "\xC1"; // N indicates which compression process
const JPG_SOF2 = "\xC2"; // Only SOF0-SOF2 are now in common use
const JPG_SOF3 = "\xC3"; // NB: codes C4 and CC are *not* SOF markers
const JPG_SOF5 = "\xC5";
const JPG_SOF6 = "\xC6";
const JPG_SOF7 = "\xC7";
const JPG_SOF9 = "\xC9";
const JPG_SOF10 = "\xCA";
const JPG_SOF11 = "\xCB"; // NB: codes C4 and CC are *not* SOF markers
const JPG_SOF13 = "\xCD";
const JPG_SOF14 = "\xCE";
const JPG_SOF15 = "\xCF";
const JPG_EOI = "\xD9"; // End Of Image (end of datastream)
static public function get($img_data) {
$height = $width = $type = '';
if ((substr($img_data, 0, 3) == getid3_lib_image_size::GIF_SIG) && (strlen($img_data) > 10)) {
$dim = unpack('v2dim', substr($img_data, 6, 4));
$width = $dim['dim1'];
$height = $dim['dim2'];
$type = 1;
} elseif ((substr($img_data, 0, 8) == getid3_lib_image_size::PNG_SIG) && (strlen($img_data) > 24)) {
$dim = unpack('N2dim', substr($img_data, 16, 8));
$width = $dim['dim1'];
$height = $dim['dim2'];
$type = 3;
} elseif ((substr($img_data, 0, 3) == getid3_lib_image_size::JPG_SIG) && (strlen($img_data) > 4)) {
///////////////// JPG CHUNK SCAN ////////////////////
$img_pos = $type = 2;
$buffer = strlen($img_data) - 2;
while ($img_pos < strlen($img_data)) {
// synchronize to the marker 0xFF
$img_pos = strpos($img_data, 0xFF, $img_pos) + 1;
$marker = $img_data[$img_pos];
do {
$marker = ord($img_data[$img_pos++]);
} while ($marker == 255);
// find dimensions of block
switch (chr($marker)) {
// Grab width/height from SOF segment (these are acceptable chunk types)
case getid3_lib_image_size::JPG_SOF0:
case getid3_lib_image_size::JPG_SOF1:
case getid3_lib_image_size::JPG_SOF2:
case getid3_lib_image_size::JPG_SOF3:
case getid3_lib_image_size::JPG_SOF5:
case getid3_lib_image_size::JPG_SOF6:
case getid3_lib_image_size::JPG_SOF7:
case getid3_lib_image_size::JPG_SOF9:
case getid3_lib_image_size::JPG_SOF10:
case getid3_lib_image_size::JPG_SOF11:
case getid3_lib_image_size::JPG_SOF13:
case getid3_lib_image_size::JPG_SOF14:
case getid3_lib_image_size::JPG_SOF15:
$dim = unpack('n2dim', substr($img_data, $img_pos + 3, 4));
$height = $dim['dim1'];
$width = $dim['dim2'];
break 2; // found it so exit
case getid3_lib_image_size::JPG_EOI:
case getid3_lib_image_size::JPG_SOS:
return false;
default: // We're not interested in other markers
$skiplen = (ord($img_data[$img_pos++]) << 8) + ord($img_data[$img_pos++]) - 2;
// if the skip is more than what we've read in, read more
$buffer -= $skiplen;
if ($buffer < 512) { // if the buffer of data is too low, read more file.
return false;
}
$img_pos += $skiplen;
break;
}
}
}
return array ($width, $height, $type);
} // end function
}
?>
|
