<?php
convertTo( "some-input-video.avi", "output.mp4" );
function convertTo( $input, $output ) {
   echo "Converting $input to $output<br />";
   $command = "mencoder $input -o $output -af volume=10 -aspect 16:9 -of avi -noodml -ovc x264 -x264encopts bitrate=500:level_idc=41:bframes=3:frameref=2: nopsnr: nossim: pass=1: threads=auto -oac mp3lame";
   echo "$command<br />";
   shell_exec( $command );
   echo "Converted<br />";
}
?>