dive into mark

In the beginning (of DVDs) there was CSS — the Content Scramble System, not Cascading Style Sheets ;) — which was famously cracked many years ago by “DVD Jonâ€. CSS is technically optional (for example, Jason Scott’s excellent BBS Documentary doesn’t use it) but virtually every commercial DVD uses it.

It is possible that the warning you [Dave] saw referred to CSS protection and nothing more.

Some reference material:

Also since the beginning, DVDs have had the option of embedding a region code in the DVD disc. Different regions of the world were assigned different codes, and every DVD player manufacturer had to sign an agreement with the DVD Consortium stating that they would only play DVD discs of a certain region. And the manufacturers had to play by the Consortium’s rules, because the Consortium was the only one who could give out the decryption keys that would allow the player to decrypt the CSS encryption used on commercial DVDs.

Despite these agreements, in some regions of the world (i.e. everywhere but the United States), there was a growing market for “multi-region†DVD players which would play DVDs from anywhere, i.e. a DVD player in the UK (region 2) which could play DVDs from the US (region 1). (Many were region-locked by default but had secret codes that could enable the extra functionality.) To counteract this trend, Columbia Tristar and Warner Home Video attempted a new scheme called “region code enhancement†(RCE). An RCE-protected DVD disc contains executable code that asks the DVD player what regions it supports, and refuses to play the disc if it didn’t like the answer. All DVDs can contain executable code which is executed by the DVD player – that’s how menus and other features work. But this code tried to outwit the “multi-region†DVD players in order to enforce in software the region encoding scheme that the players refused to support in hardware. There were various improvements to RCE over the years, as multi-region players adapted to older techniques.

It is possible that the warning you saw referred to RCE protection. “Multi-region†DVD players – even ones made by legitimate mainstream manufacturers – have been called “unlicensed†or “unapproved†devices by studios still trying to divide the global permeable marketplace into regions with impermeable boundaries and sharp corners.

Eventually the multi-region DVD players got so smart that they were software-indistinguishable from region-locked players, and the studios gave up and focused on a new threat: DVD ripping programs. As I mentioned earlier, DVDs contain executable code that tells the player what to do next – go to this menu, set this register, jump to this track or chapter, etc. That means that in the normal course of playing a DVD, there could be tracks (or individual chapters within a track) that you would never reach. Even if you tried to reach them (by using navigation buttons for “next track†or “next chapter†or whatever), those are really just commands to the DVD player and they can be overridden by code on the DVD disc that tells the DVD player to do something else. So the disc could have a bogus track or a damaged sector, and on a regular (*cough* “approved†*cough*) DVD player you would never even notice.

But DVD ripping programs don’t execute code; they blindly read every byte off the disc and decrypt it. So Sony introduced ARccOS protection, which involved placing intentionally bad sectors in parts of the DVD disc and then programming the disc to never go there during the normal course of playing it. Of course, DVD ripping programs were quickly updated to read the DVD directory structure to determine which tracks and sectors were never actually used, and if they found a bad sector in one of those tracks they simply skipped over it without complaining.

It is possible that the warning you saw referred to ARccOS protection. Sony licenses it to various other studios, and reports of its death have been greatly exaggerated. (“Pirates of the Caribbean: Dead Man’s Chest†is reported to use it, and it just came out on DVD last month.)

In 2005, Macrovision introduced yet another protection scheme called RipGuard. I have not been able to find a whole lot of technical details about how it works, except that they essentially reverse-engineered several DVD ripping programs and created a protection scheme that exploited as-yet-unknown bugs in those programs. They also claim to be able to “update†the protection for new discs as bugs are fixed in the ripper programs. (Later in 2005, Macrovision actually bought the IP for DVD Decrypter, which was at the time the most popular program for Windows, and updated RipGuard so DVD Decrypter wouldn’t work.) So basically, “RipGuard†is just a generic catch-all term for “here’s all the ways we’ve found to fuck with you so far, but be sure to ask again tomorrow.â€

It is possible that the warning you saw referred to RipGuard protection.

As you correctly pointed out, without buying the discs and opening the package, there is no way to be sure which protection scheme (or combination of protection schemes!) are present, and therefore whether the discs would work in your gift recipient’s DVD player.

Ironically, every modern DVD ripping program can easily auto-detect and auto-bypass all of these protection schemes, and then re-author the disc onto ultra-cheap recordable media with no protection whatsoever. If you wanted to ensure a smooth Christmas morning (and didn’t mind breaking several federal laws), you should buy the discs and re-author them unprotected, and keep the originals in a drawer. As I said in my first blog post ever, “the only long-term effect of copy protection is to ensure that those who defeat it are immortalized.â€