imagemagick - Watermark on animated gif with php

Question

I need a function that adds a watermark to an animated gif. How I can do that with PHP and ImageMagick?

This is my code, but it doesn't work.

function IMagickWatermark($sf, $sfDest, $sfLogo, $sGravity='southeast'){
        //$sCmd = "composite -compose bumpmap -gravity $sGravity $sfLogo "$sf" $sfDest";
        $sCmd = "convert "$sf" -coalesce -gravity south -draw 'image over 0,0 0,0 "$sfLogo"' "$sfDest"";
        exec($sCmd);
        return 1;
    }
$sf = $_SERVER['DOCUMENT_ROOT']."/test/source.gif";
$sfDest = $_SERVER['DOCUMENT_ROOT']."/test/dest.gif";
$sfLogo = $_SERVER['DOCUMENT_ROOT']."/test/logowithtext.gif";
IMagickWatermark($sf, $sfDest, $sfLogo, $sGravity='SouthEast');

Answer 1

Try this:

$animation = ani.gif; 

$watermark = logo.png; 

$watermarked_animation = "morph.gif"; 

$cmd = " $animation -coalesce -gravity South ". 
" -geometry +0+0 null: $watermark -layers composite -layers optimize "; 

exec("convert $cmd $watermarked_animation ");