ffmpeg在wamp上工作而不是xampp

I have created thumbnail image file of video file using ffmpeg in php. It is successfully working on wamp server.Now want to use it in xampp server but its not working.... This is my code for creating thumbnails:

    $ffmpeg = "C:\\ffmpeg\\bin\\ffmpeg";
    $videoFile = implode($_FILES["file"]["tmp_name"]);

    $imageFile = "thumb/".time()."_thumbs.jpg";
    $size = "800x420";

Why its not working on xampp... Thanks !!!! $getFromSecond = 25; $cmd = "$ffmpeg -i $videoFile -an -ss $getFromSecond -s $size $imageFile";

Try to enable "extension=php_ffmpeg.dll" directive in your php.ini.