title: Watermark on animated gif with php
body: <p>I need a function that adds a watermark to an animated gif. How I can do that with PHP and ImageMagick?</p>
  
  <p>This is my code, but it doesn't work.</p>
  
  <pre><code>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');
  </code></pre>