My problem is similar to a closed question: Watermark on animated gif with php
But how to use it? It's not like the PHP syntax. I try this:
<?php
$animation = 'images/gif/oleni.gif';
$watermark = 'gallery/258e5b33191223215aa05f55460aed2f.png';
$watermarked_animation = 'morph.gif';
$cmd = ' $animation -coalesce -gravity South '.
' -geometry +0+0 null: $watermark -layers composite -layers optimize ';
exec('convert $cmd $watermarked_animation ');
?>
And nothing happened. How to use this solution?