PHP determines whether a GIF picture is a dynamic picture _php tips

This example describes how PHP determines whether a GIF picture is a dynamic picture. Share to everyone for your reference. The specific methods are as follows:

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

Examples are as follows:

Copy Code code as follows:

/*
* Determine whether 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 picture is animated (multiple frames)

Copy Code code 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
GIF animations are gif89 formatted and find gif89 at the beginning of the file. But a lot of transparent pictures are also used in 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 an extended feature segment in a GIF image, and ' NETSCAPE2.0 ' is the name of the program that extends the function execution
The program code is as follows:

Copy Code code 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 ' really animation ';
}else{
Echo ' is not animated ';
}
?>

The test found that it was sufficient to read 1024 bytes because the stream of data being read contains exactly the Chr (0x21). chr (0xff). chr (0x0b). ' NETSCAPE2.0 '

I hope this article will help you with your PHP program design.