Convert string to JSON array using Perl

original json file (note: the string values are delimited by a colon)
[
{"cxbrandid":"100158:100159","cxbrandname":"APPLE, ORANGE & BANANA:JUICE JUICE"},
{"cxbrandid":"3000","cxbrandname":"JUNGLE, FOREST"}
]

desired output json file:

[{"cxbrandid":["100158","100159"],"cxbrandname":["APPLE, ORANGE & BANANA","JUICE JUICE"]},{"cxbrandid":["3000"],"cxbrandname":["JUNGLE, FOREST"]}]

Perl script to do that:
========================================================================
use JSON;

my $json;
{
  local $/; #Enable 'slurp' mode
  open my $fh, "<", "t.json";
  $json = <$fh>;
  close $fh;
}
my $data = decode_json($json);

#count number of elements in array and minus one
$t = scalar(@{$data});
$t = $t - 1;

for (my $i=0; $i <= $t; $i++) {

$cxbrandname =  $data->[$i]->{'cxbrandname'};
$cxbrandid = $data->[$i]->{'cxbrandid'};

my $brandidtable=[];
my $brandnametable=[];

@cxbrandidarray=split(/:/, $cxbrandid);
@cxbrandnamearray=split(/:/, $cxbrandname);

foreach my $val (@cxbrandidarray) {
  push @{$brandidtable}, $val;
}

foreach my $val (@cxbrandnamearray) {
  push @{$brandnametable}, $val;
}

$data->[$i]->{'cxbrandid'}= $brandidtable;
$data->[$i]->{'cxbrandname'}= $brandnametable;

}

open my $fh, ">", "data_out.json";
print $fh encode_json($data);
close $fh;