Try this
<?php
$software_path ="C:\\wamp\www\wellelafa\SWFTools\pdf2swf.exe" ;
$pdf_path ="C:\\wamp\www\wellelafa\SWFTools\1.pdf" ;
$swf_output ="C:\\wamp\www\wellelafa\1.swf" ;
$cmd =$software_path . " -b " . $pdf_path . " -o " . $swf_output";
exec($cmd);
?>