PHP to determine whether a GIF picture is a dynamic picture method, _php tutorial

PHP to determine whether a GIF image is a dynamic image method,

This example describes how PHP determines whether a GIF image is a dynamic image. Share to everyone for your reference. Here's how:

How to use PHP to determine whether a GIF picture is a dynamic picture (animation)? The first thought is that using the getimagesize () function to look at the type value, the discovery is GIF, so this method is not feasible. Here is a function that the author sees on the Internet to determine whether GIF is a dynamic graph. Post it and share it with you

Examples are as follows:
Copy CodeThe code is as follows:/*
* Determine if the picture is a dynamic picture (animation)
*/
function Isanimatedgif ($filename) {
$FP =fopen ($filename, ' RB ');
$filecontent =fread ($fp, FileSize ($filename));
Fclose ($FP);
Return Strpos ($filecontent, Chr (0x21). chr (0xff). chr (0x0b). NETSCAPE2.0 ') ===false?0:1;
}
Or do this:
Use PHP to determine if a GIF image is animated (multi-frame)
Copy CodeThe code is as follows: <?php
function Isanimatedgif ($filename)
{
$fp = fopen ($filename, ' RB ');
$filecontent = Fread ($fp, FileSize ($filename));
Fclose ($FP);
Return Strpos ($filecontent, Chr (0x21). chr (0xff). chr (0x0b). NETSCAPE2.0 ') = = = False?0:1;
}
Echo isanimatedgif ("51windows.gif");
?>
Example 2
The GIF animation is in gif89 format and the file starts with gif89. But many transparent pictures are also used in the gif89 format,
Google to: You can check whether the file contains: Chr (0x21). chr (0xff). chr (0x0b). NETSCAPE2.0 '
Chr (0x21). Chr (0xff) is the header of the extended function segment in a GIF image, and ' NETSCAPE2.0 ' is the program name that the extended function executes
The program code is as follows:
Copy CodeThe code is as follows: <?php
function Check ($image) {
$content = file_get_contents ($image);
if (Preg_match ("/". Chr (0x21). chr (0xff). chr (0x0b). ' NETSCAPE2.0 '. " /", $content)) {
return true;
}else{
return false;
}
}
if (check ('/home/lyy/luoyinyou/2.gif ')) {
Echo ' is really animated ';
}else{
Echo ' is not animated ';
}
?>
The test found that reading 1024 bytes is sufficient because the data stream being read exactly contains Chr (0x21). chr (0xff). chr (0x0b). NETSCAPE2.0 '

I hope this article is helpful to everyone's PHP programming.

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