You like DRM ? You’ll enjoy CPRM !

Well, almost. Let’s have it the easy way : CPRM stands for Copy Protection for Removable Media. That’s a copy protection system made to prohibit copying of burnt DVD with “couch” DVD recorder. At first, CPRM was intended to prevent duplication of copyrighted material broadcasted over the air. That’s to say : if a copyrighted movie – or so – is flagged CPRM, your home DVD recorder will encrypt it in order to prevent modification or duplication. Is that alright? It’s the beginning of the theory…

A reader from the french magazine l’Ordinateur Individuel sent me a DVD-RW burnt with his own domestic DVD recorder Pioneer DVDR-720 : that disk has problems to be read on his PC. That recorder is “compliant” with CPRM. I loaded it in my PC : Windows XP sees a blank CD-RW; Linux sees a blank DVD-RW. Funny enough. Under Mac OX, the disk cannot be read.

To play that disk, I launched Nero Showtime. It worked fine. I assume WinDVD and PowerDVD would have worked the same way as they seem to be CPRM compliant. But neither a Linux app nor a Mac OS X app has been able to play the disk. Gosh!

While reading the specs of CPRM, on its promoting website, I learnt that this system relies on the encryption of the full content of the disk. For a CPRM encoded disk to be read, the player must be fully compatible. With a PC, that means the hardware player and the software player must be compatible. For the hardware players, a simple firmware update seams to be enough. Club CD Freaks just got aware of the issue. The last versions of software players seems to be compliant.

So, what’s the problem? First, CPRM forbids to modify – like remove the ads – the content of the disk, or rip it – DVD Decrypter just sees a blank disk. Worst, The consortium in charge for the promotion of optical rewritable disks, the RWPPI, shows a worrying compatibility list. This one indicates that most of the home DVD recorders made by JVC, Nec, Sanyo, Sharp, Sony et Toshiba sport CPRM. But, this same list also indicates that most of the home DVD players don’t support it. Does that mean that recorded DVD with CPRM aren’t playable by regular home DVD players? I’m not sure as I didn’t find anyone who has conducted an extensive test but it’s quite assumable.

That’s already worrying, but that’s not all. The Pioneer DVDR-720 DVD recorder seems, according to the reader who sent me his disk, to be also “protecting” recordings from a camera… And that’s scary. Have you ever seen a DVD recorder tagged “CPRM compliant” ?

If you have problems with DVDs burnt with your home DVD recorder, please tell me.

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