use XML::Smart ;
my $XML = new XML::Smart(q`
<root>
<output name='123'>
  <frames format='a'/>
  <frames format='b'/>
</output>
<output name='546'>
  <frames format='c'/>
  <frames format='d'/>
</output>
</root>
`,'smart');

$XML = $XML->cut_root ;

my $show = 123 ;

my @output = @{ $XML->{output}('name','eq',$show){frames} } ;


print "\n == Available Frame Formats For $show ==";
foreach my $o (@output ){
  print "\n $o->{format}" ;
}

##</code><code>##

 == Available Frame Formats For 123 ==
 a
 b