You could probably do something like this:

$ echo "ABBCBCAAAAABBCBCACCCAAAAACAAAAABBBBBAAAAABBAAAAAAAABBCCCACCAAB
+C
BCCCBCAACAABBBCAAACCAAAAACAAAAABBBBBAAAAABBAAAAAAAABBCCCACCABBC
ABCCBBBAAAABBABCACABCCCCCCAAAAABBCBBCCCCAAAAAAAAAAAAACCCACCACCC" | per
+l -le'
use Data::Dumper; $Data::Dumper::Useqq = 1;
my %alphabet = qw/ A 00 B 01 C 11 /; my %rev_alpha = reverse %alphabet
+;
while ( <> ) {
    chomp;
    print length(), " ", $_;
    # compress
    my $data = pack "B*", join "", map $alphabet{ $_ }, split //;
    print length $data, " ", Dumper $data;
    # decompress
    my $uncp = join "", map $rev_alpha{ $_ }, map /../g, unpack "B*", 
+$data;
    print length $uncp, " ", $uncp, "\n";
    }
'
63 ABBCBCAAAAABBCBCACCCAAAAACAAAAABBBBBAAAAABBAAAAAAAABBCCCACCAABC
16 $VAR1 = "\27p\1w?\0000\1U\0\24\0\1\177<\34";

64 ABBCBCAAAAABBCBCACCCAAAAACAAAAABBBBBAAAAABBAAAAAAAABBCCCACCAABCA

63 BCCCBCAACAABBBCAAACCAAAAACAAAAABBBBBAAAAABBAAAAAAAABBCCCACCABBC
16 $VAR1 = "\177p\301\\\17\0000\1U\0\24\0\1\177<\\";

64 BCCCBCAACAABBBCAAACCAAAAACAAAAABBBBBAAAAABBAAAAAAAABBCCCACCABBCA

63 ABCCBBBAAAABBABCACABCCCCCCAAAAABBCBBCCCCAAAAAAAAAAAAACCCACCACCC
16 $VAR1 = "\37T\1G1\377\360\1u\377\0\0\0?<\374";

64 ABCCBBBAAAABBABCACABCCCCCCAAAAABBCBBCCCCAAAAAAAAAAAAACCCACCACCCA
[download]

One of the problems with this is that "00" is a valid value so you get extra "A"s padding the right hand side of the string on decompression.

If you change the alphabet to:

01  A
10  B
11  C
[download]

It will decompress properly:

$ echo "ABBCBCAAAAABBCBCACCCAAAAACAAAAABBBBBAAAAABBAAAAAAAABBCCCACCAAB
+C
BCCCBCAACAABBBCAAACCAAAAACAAAAABBBBBAAAAABBAAAAAAAABBCCCACCABBC
ABCCBBBAAAABBABCACABCCCCCCAAAAABBCBBCCCCAAAAAAAAAAAAACCCACCACCC" | per
+l -le'
use Data::Dumper; $Data::Dumper::Useqq = 1;
my %alphabet = qw/ A 01 B 10 C 11 /; my %rev_alpha = reverse %alphabet
+;
while ( <> ) {
    chomp;
    print length(), " ", $_;
    # compress
    my $data = pack "B*", join "", map $alphabet{ $_ }, split //;
    print length $data, " ", Dumper $data;
    # decompress
    my $uncp = join "", map $rev_alpha{ $_ }, map /../g, unpack "B*", 
+$data;
    print length $uncp, " ", $uncp, "\n";
    }
'
63 ABBCBCAAAAABBCBCACCCAAAAACAAAAABBBBBAAAAABBAAAAAAAABBCCCACCAABC
16 $VAR1 = "k\265V\273\177UuV\252UiUV\277}l";

63 ABBCBCAAAAABBCBCACCCAAAAACAAAAABBBBBAAAAABBAAAAAAAABBCCCACCAABC

63 BCCCBCAACAABBBCAAACCAAAAACAAAAABBBBBAAAAABBAAAAAAAABBCCCACCABBC
16 $VAR1 = "\277\265\326\255_UuV\252UiUV\277}\254";

63 BCCCBCAACAABBBCAAACCAAAAACAAAAABBBBBAAAAABBAAAAAAAABBCCCACCABBC

63 ABCCBBBAAAABBABCACABCCCCCCAAAAABBCBBCCCCAAAAAAAAAAAAACCCACCACCC
16 $VAR1 = "o\251V\233v\377\365V\272\377UUU\177}\374";

63 ABCCBBBAAAABBABCACABCCCCCCAAAAABBCBBCCCCAAAAAAAAAAAAACCCACCACCC
[download]