$string1 = '<param name="movie" value="http://www.youtube.com/v/ase24sd2_34&somevar=someval">'; 
$string2 = '<param name="movie" value="http://someservice.com/ase24sd2_34">'; 
  
$regex = '/<param name="movie" value="(http:\/\/[^&"\'\s]+)/i'; 
  
preg_match_all($regex, $string1, $matches, PREG_SET_ORDER); 
print_r($matches); 
preg_match_all($regex, $string2, $matches, PREG_SET_ORDER); 
print_r($matches);