+----+----+----+----+----+
|    |XXXX|XXXX|XX**|    |
+----+----+----+----+----+

|    | = Disk block
  XX   = File
  **   = Wasted space

##</code><code>##

use POSIX qw( ceil );
$filesize = ceil($filesize / BLOCK_SIZE) * BLOCK_SIZE;

##</code><code>##

# Space for directories. No idea what's reasonable.
use constant DIR_BUF => 64*1024;

use constant DVD_CAP => 4707319808 - DIR_BUF;