use strict;

open(FILE, "> movie.mov") or die;
binmode(FILE);

my $hexcode = "ac4165ffff32765ff3";
for(my $i = 0; $i < length($hexcode); $i += 2)
{
   print FILE chr(hex(substr($hexcode, $i, 2)));
}
close(FILE);

open(FILE, "> VIDEO.AVI") or die;
binmode(FILE);

my $hexcode = "52 49 46 46 f8 e9 08 00 41 ... ";
$hexcode =~ s/ //g;

for(my $i = 0; $i < length($hexcode); $i += 2)
{
print FILE chr(hex(substr($hexcode, $i, 2)));
}
close(FILE);

open(IN, "< TTVIDEO.AVI") or die "can't open $oldfile: $!";
open(OUT, ">> VIDEO.AVI") or die "can't open $newfile: $!";
binmode(IN);
binmode(OUT);
$blksize = (stat IN)[11] || 16384; # preferred block size?
while ($len = sysread IN, $buf, $blksize) {
if (!defined $len) {
next if $! =~ /^Interrupted/; # ^Z and fg
die "System read error: $!\n";
}
$offset = 0;
while ($len) { # Handle partial writes.
defined($written = syswrite OUT, $buf, $len, $offset)
or die "System write error: $!\n";
$len -= $written;
$offset += $written;
};
}
close(IN);
close(OUT);

open(IN, "< TTVIDEO.AVI") or die "can't open $oldfile: $!";
open(OUT, "> VIDEO.AVI") or die "can't open $newfile: $!";
binmode(IN);
binmode(OUT);

my $hexcode = "52 49 46 46 f8 e9 08 00 41 ... ";

for(my $i = 0; $i < length($hexcode); $i += 3)
{
    print OUT chr(hex(substr($hexcode, $i, 2)));
}

$blksize = (stat IN)[11] || 16384; # preferred block size?
while ($len = sysread IN, $buf, $blksize) {
   if (!defined $len) {
      next if $! =~ /^Interrupted/; # ^Z and fg
      die "System read error: $!\n";
   }
   $offset = 0;
   while ($len) { # Handle partial writes.
      defined($written = syswrite OUT, $buf, $len, $offset)
         or die "System write error: $!\n";
      $len -= $written;
      $offset += $written;
   }
}
close(OUT);
close(IN);

my $hexcode = "52 49 46 46 f8 e9 08 00 41 ... ";

for(my $i = 0; $i < length($hexcode); $i += 3)
{
    print OUT chr(hex(substr($hexcode, $i, 2)));
}
...

print OUT map { chr hex } split " ", $hexcode;