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.
You should know: the protection is in the drive, not on the dvd i guess only the minus type of media -R -RW /recorder
so if you have old hardware it should be okay, because on the disc is only a tag/flag that doesn’t trigger the old hardware, but plays it, and is backwards compatible.
The disk sent to me causes problems with two recent internal Philips DVD drives and a not-so-young Lite-On LDW-811S drive, but seems to be accessible with an old external Iomega drive.
Your comment is interesting but it does not quite seem to fit in with the information provided by the promoters of CPRM, the 4C Entity. According to their docs, device AND media must be CPRM compliant and the content is ALSO encrypted.
Edit: I added a pic extracted from the 4C Entity CPRM Base 1.0 (Introduction and Common Cryptographic Elements) document. It’s avaible on the 4C web site.
For reference, 4C Entity counts Intel, IBM, Matsushita and Toshiba as members.
Compliant in this case means: for the protection to ‘work’ !
you have full access through non compliant DVD-ROM player.
the CP’R'M or CP’P'M protected media is backwards compatible on old hardware.
Otherwise the protected disc will only play on the DVD video recorder, and no other (standalone)player, using a DVD video recorder that has also a hard drive: the first copy of a broadcast will always be the one on the hard drive, and is a part of the protection i guess, and a dis-advantage for the user. better record direct on dvd media.
and … use only plus DVD video recorders and media.
First, compliance doesn’t seem to mean what you say. According to the official docs, to the testimonies I gathered and to sample I’ve been sent :
- full compliance (DVD recorder and DVD media) means that the content will be encrypted on the DVD and only readable by compliant DVD player and not by any any non compliant DVD player ;
- half compliance (DVD recorder but not DVD media) means that the content will not recorded at all;
- non compliance at all seems to mean that the content will be recorded without a problem and with no encryption. Unfortunatly, most DVD recorders seems to be compliant today.
As DVD recorders with a hard drive, the record on the hard drive doesn’t seem to counted at all : CPRM is not implemented in ATA specification. That’s to say that copy from the HD to the DVD drive should be a problem – as long as you use CPRM compliant media with a CPRM compliant DVD burder or that your DVD recorder is not compliant at all with CPRM.
As far as I understand the official docs from 4C, the DVD record is the first copy.
I fully a agree with your suggestion to use only DVD+R/+RW recorder and media to avoid CPRM. But, for example, Pioneer does only make DVD-R/-RW CPRM compliant devices…
It’s not official CPRM > ATA but:
http://www.theregister.co.uk/2001/02/18/cprm_on_ata_full_coverage/
I bought an old DVD ROM player, 7,50 euro, and as i suspected, it did play the CPRM protected discs i’ve got, the combination of extracting them with DVDdecrypter will make the files available to normal use, like editing, i guess the ID near the center of the disc, is not used this way, you now can also use plus media to put he files on,
btw layout is much better now, only the character’s color…:(
Thanks a lot Eric for your testimony. That confirms that CPRM compliant firmware prohibits access to the directory for softwares that are not CPRM compliant.
Thanks also for your comments about the layout. I’ll fine tune it soon.
Thank you, yes, layout is now perfect so, i have a Asus Pundit-R (barebone) connected to my normal
tv, so i can use it as multimedia center for a lot of things, and CPRM isn’t much helping that way, i was hoping to expand to a LCD/Plasma screen, now with these « digital » limitations i have to be careful, bacause now i’m afraid, that the HDMI (also with protection features) will make it more to fail if somewhere it picked up another tag of some sort…
The DVD video recorder here isn’t accepting any NTSC signal so far, while you can play a NTSC dvd in most European dvd standalone players, because it is converted to PAL60, which most of the recent tv’s will accept, and that’s a simple feature….
Yar! hi!… my home DVD is Pioneer DVDR-720 DVD… now my local shop doesn’t sell any of CPRM DVD recorder disc.. so i want to reused those that i had bought but i want to back up those i have recorded.. is there a way? If can please reply to my email! thanks!
You can try rip (DVDdecrypter or like wise) these discs in a non-CPRM drive/burner,
and burn these projects also with a non-CPRM burner..
use only plus media, or only exeption >minus media: TDK 16 speed version2.1 revision 6.0 (or higher)
On window xp With inter video I can not play a movie that I recorded on DVD Ram,cprm and DVD-R in Panasonic player/recorder from a digita tv station. I can play back the same DVD on Window Vista That Also has Inter video. Anyone help, thanks