use strict;
use warnings;

my $data='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';

$data = pack('H*', $data);

use POE::Filter::Block;

sub _myencode { print STDERR "_myencode\n" };
sub _mydecode {
  my $stuff = shift;
  print STDERR "M1: ", unpack('H72', $$stuff), "...\n";

  # Extract everything through 1st 0xfe{4} flag, up to the 2nd...
  $$stuff =~ /^(.*?\xfe{4}.*?)(\xfe{4})/s || return;

  # Return its measured length (in characters)...
  my $length = length($1);
  return($length);
}

my $filter = POE::Filter::Block->new( LengthCodec =>
	[ \&_myencode, \&_mydecode ]
);

$filter->get_one_start([ $data ]);

while (1) {
  my $block = $filter->get_one();
  last unless @$block;
  print STDERR "M2: ", unpack('H72', $block->[0]), "...\n",
	length($block->[0]), " characters\n";
}