BD-ROM Mark

In association with heise online

BD-ROM Mark is yet another anti-copy protection measure for Blu-ray. It consists of a small block of encrypted data stored in a separate area from the majority of on-disc data. Licensed specialised hardware is required to create this data block at the duplication plant. This is read only by the playback drive and is not present on the data exiting the drive so it will be absent from any copies made. Commentators say that at least one aim of BD-ROM Mark is perhaps to make it more difficult for replication plants to do unlogged over-runs on a pressing. The over-runs being sold out the back door, without the copyright holder's knowledge.

Playing Blu-ray movies on Linux

Strictly speaking DRM protected Blu-ray movies cannot be played direct from the Blu-ray disc itself on a Linux system because the only method that has been explored at the moment involves decrypting and copying the contents of the Blu-ray disc to hard disk and then playing the movie from the hard disk file. In many countries this process is illegal because it involves breaking and removing DRM from the original copy.

Blu-ray and Ubuntu

There is some help documentation for methods of playing Blu-ray using the popular Ubuntu distribution. Unfortunately this information offers false hope because, although it shows a proof-of-concept method that seems to have worked at one time, the AACS LA have gone through at least one key revocation cycle since then and the provided decryption tools no longer work without a current key. The method given by the developer for key retrieval from current commercial Windows Blu-ray playback software does not appear to work.

Even given current keys, as previously mentioned, this method is cumbersome and still does not offer true playback from the disc, since the decrypted movie files must be played back from hard disk.

DRM-free Blu-ray will play back with the correct UDF drivers, player software and CODECs installed.

A clash of ideologies

The difficulty Linux has in accommodating DRM brings into focus the clash in ideologies between the free and open source movement and the manufacturers of commercial proprietary software.

Linux is not alone in lacking DRM support: current Apple Macs will not play Blu-ray discs, leaving Microsoft Windows as the only operating system with full DRM and Blu-ray support.

Ultimately the difference between commerce and the open source movement comes down to survival strategies. Commercial, profit-driven companies tend to act selfishly, focussing only on their own comfort and survival, while open source communities think in terms of the benefit and survival of society as a whole, through cooperation and sharing. Commercial thinking leads to competition for resources, secrecy and a growing need for control and dominance. Not surprisingly this tends to generate paranoia in those involved in open source, since open source is dedicated to the idea of allowing the individual control over the systems they use.

DRM technologies have been developed as a direct result of the commercial need for control, initially as a profit protection mechanism. However, it's beginning to seem that the natural tendency for companies to try and exert more and more control has gone too far and is no longer simply about protecting companies' revenue streams, but is now concerned with dictating to their customers exactly what they can and can't do with a product once they have paid for it. Having paid for a copy of a movie or a music track customers expect, not unreasonably, to be able to play that file for their own private use anywhere and using any combination of hardware and software they choose. However, if the major content providers have their way and DRM is taken to its logical conclusion, consumers will no longer be able to buy copies of films or audio recordings, but only to rent them. Further, the content providers will be able to physically stop playback at any time.

From the end user's viewpoint, they should, in theory at least, have the choice of eschewing the purity of open source and buying licensed proprietary plug-ins for their individual Linux installations, allowing them to play DRM protected media – if such plug-ins were available. So far, commercial distrust of the Linux community ideals means that such plug-ins are not generally available.

Given that the proprietary commercial software and open source ideologies seem diametrically opposed, it is hard to see how open source can adapt to DRM and at the moment the commercial lobby would seem to have the clout to impose the general use of DRM and not worry about locking open source out in the cold.

See also:

Microsoft Windows Digital Rights Management, Microsoft's web pages on the Windows DRM system.
Hacking Digital Rights Management, ArsTechnica article on hacking DRM.
Flame Linus to a crisp!, fa.linux.kernel thread where Linus Torvalds discusses DRM.
Content Scrambling System (CSS), transcription of a Carnegie Mellon School of Computer Science lecture by Gregory Kesden on the design of CSS.
Welcome to GPLv3, details of changes between GPLv2 & 3 from The Free Software Foundation, including video from Richard Stallman.
A Quick Guide to GPLv3, a quick guide to GPLv3 from the Free Software Foundation.
Playing Blu-ray discs on Ubuntu 8.10, the Ubuntu help page on Blu-ray.
HDMI cable pinout