lsb-time.pl

use warnings;
use DateTime;

$snum    = 0;
$writing = 0;

open OUT, "|sox -t .raw -e unsigned-integer -b 16 -r 44100 ".
          "-c 1 - stamped.wav";

while (not eof STDIN) {

  read STDIN, $sample, 2;
  $sample = unpack "s", $sample;

  if ($writing) {
    $bit = (ord(substr($code, $pos >> 3, 1)) >> ($pos % 8)) & 1;
    if (++$pos >= length($code) << 3) {
      $writing = 0;
      $bit     = 0;
    }
  } elsif ($snum++ % 44100 == 0) {
    $writing = 1;
    $pos     = 0;
    $bit     = 1;
    $code    = DateTime->now()->iso8601();
  }

  print OUT pack("S", ($sample + 0x7FFF) & 0xFFFE | $bit);
  
}
close OUT;