gistfile1.txt

my $tmpl1
    = $file->{file_name} =~ /\.(avi|divx|mkv|flv|mp4|wmv)$/i 
                                                         ? 'download1_video.html'
    : $file->{file_name} =~ /\.mp3$/i                    ? 'download1_audio.html'
    :                                                      'download1.html'
    ;

# or

my $video_re = qr{\. (avi|divx|mkv|flv|mp4|wmv) $}xi;
my $tmpl1
    = $file->{file_name} =~ $video_re   ? 'download1_video.html'
    : $file->{file_name} =~ /\.mp3$/i   ? 'download1_audio.html'
    :                                     'download1.html'
    ;

# or

my $name = $file->{file_name};

my $tmpl1
    = $name =~ /\.(avi|divx|mkv|flv|mp4|wmv)$/i    ? 'download1_video.html'
    : $name =~ /\.mp3$/i                           ? 'download1_audio.html'
    :                                                'download1.html'
    ;