CPRM Discussion Thread

[Fugitive]

Thankyou Gogela, reading from your Smilies, i understand
my (short) message is understand, i hope many will follow,
I think the CPRM issue is very important and i think people
should be aware of this, but i'm affraid CPRM already slipped
in a lot of homes, without people knowing this, it happend
to me too.

[eltranquil]

Originally Posted by Fugitive

Thankyou Gogela, reading from your Smilies, i understand
my (short) message is understand, i hope many will follow,
I think the CPRM issue is very important and i think people
should be aware of this, but i'm affraid CPRM already slipped
in a lot of homes, without people knowing this, it happend
to me too.

Well, since this feature is probably firmware-dependent, isn't it better to specify the firmware version too? Could be that a non-CPRM drive becomes CPRM-aware with a firmware update (I doubt that the reverse can happen)...

ET

[Fugitive]

Yes, you're right, but i guess no manufacturer will
build "it" in, and then later disable it in it's firmware,
(If it's not one and the same)
costs aspects i guess, but yes, you should ask this question,
because i guess downgrading the firmware in the drive is not
possible in most cases! only a new and hacked firmware can do this.
Also, CPRM is mostly used on the "minus" > -R -RW & -RAM media,
and it is "proposed" to be a feature of the ATA specs, so some of the features could be used on Hard-Disks, CPRM has always been a standard feature of the -RAM DVD media...

[Fugitive]

You are completly right ! so from now on: Also the firmware
version of the drive should be listed with the drive,
this could also prevent conflicts i guess.
I see you're the moderator, so you have my permission to add
this to my initial post.

[Fugitive]

Originally Posted by chas0039

YES: NEC 3500, NEC 3520, Liteon 1693, LG 4163, Liteon 167T, Liteon 16P9S

NO: BenQ 1620, AOpen 1648 AAP, Pioneer 116

I have never encountered any disc with any form of CPRM.

Thankyou chas0039
its only used on minusR media, so maybe it's not such a disaster as i thougt it would be..

[chas0039]

Originally Posted by Fugitive

...or a new movie on DVD-Video your pc drive will not see this disc, a

I am missing something. How can this only apply to -R media if you say it is on a DVD-Video?

I am aware of the potential inclusion in on air broadcasts and the shut down of the manditory hardware requirement last Summer, but I have yet to see this on a pressed DVD.

BTW, most of the drives I listed above were using codeguy's firmware or L&D's so I skipped listing it. The interesting question will be if it is firmware dependant, will it be removable.

[Fugitive]

Originally Posted by chas0039

I am missing something. How can this only apply to -R media if you say it is on a DVD-Video?

I am aware of the potential inclusion in on air broadcasts and the shut down of the manditory hardware requirement last Summer, but I have yet to see this on a pressed DVD.

BTW, most of the drives I listed above were using codeguy's firmware or L&D's so I skipped listing it. The interesting question will be if it is firmware dependant, will it be removable.

The minus R media is according to the approved dvd "rules"
of the DVD consortium or something like that,
and has also the CPRM rules in it (specs. minus media -RAM also)
plus R media does not support CPRM, so best bet is to read
minus R media with drive that has only plus R specs. (old drive) or licenced software, that controls the CPRM functions, in CPRM compatible drive,
I recently installed the 1.02 fw. in my 740 Plextor drive,
PlextoolsProXL can now read a CPRM protected disc, but Windows can't, when clicked up on it still asks for a disk,
While PlextoolsProXL already made an image of it,
and a disc burned of this image, is still not seen by Windows, go figure....

[chas0039]

And why do you think this protocol will show up on pressed DVDs?

[Fugitive]

Originally Posted by chas0039

And why do you think this protocol will show up on pressed DVDs?

Then it's called CPPM P=pressed CPRM R=recordable

something to read:

http://www.4centity.com/docs/doc_request_thanks.html

[Fugitive]

Originally Posted by chas0039

And why do you think this protocol will show up on pressed DVDs?

Also, the protocol isn't on the disc, it's in the drive, the operating system of the hardware itself, reads the tags/flags
on the disc.
So a drive without the CPPM/CPRM mechanism, can also read/play the disc, but for now, i don't know, if you can play these files, once you have copied them onto other media.

[Fugitive]

Originally Posted by VirusHack

Just my two drives:

Drive: BenQ DVD DD DW1620 (DVD±R/RW DL Recorder)
Firmware: B7W9
CPRM: No

Drive: Lite-On Combo SOHC-5232K (Combo Drive DVD-ROM/CDRW)
Firmware: NK0J
CPRM: Yes

VH

Say, is it your signature, or are you just glad to see me ?

Sorry, VH, for this one, i couldn't resist it, thanks for listing your drive(s) CPRM specs.

[VirusHack]

Originally Posted by Fugitive

Say, is it your signature, or are you just glad to see me ?

How do you mean?

VH

[Gogela]

Man... I think I'm about ready to give up. CPRM is pretty damn effective... I think if it's ever going to be defeated, the app will probably have to have firmware countermeasures for any drives that support it, native mechinisms for removing CPRM from the media you want to back up, AND a virtual CPRM server on the client machine. That's a LOT of programming.

[Fugitive]

Originally Posted by Gogela

Man... I think I'm about ready to give up. CPRM is pretty damn effective... I think if it's ever going to be defeated, the app will probably have to have firmware countermeasures for any drives that support it, native mechinisms for removing CPRM from the media you want to back up, AND a virtual CPRM server on the client machine. That's a LOT of programming.

The only comfort is, that only minus R media is supported by CPRM, CPPM is more a pain in the...... neck.

I now tried a drive that is also CPRM compatible, it allows me to "see" the disc (in Windows) that came out of my dvd standalone recorder, (i recorded ClassicFMTV which has the CPRM tag up obviously) so i copied the files onto my PC's hd, from there i can play those files! when i put these (the VIDEO_TS map) onto a dvd+r disc with this drive, (Plextools video project) this disc becomes again invisible for windows and unplayable on any player only Plextools (ProXL) can make the contents visible, (map & files)
I guess an old drive, before the minus R media introduction, (not CPRM compatible) will give no problems,
if it can play this disc...

[chas0039]

Originally Posted by Fugitive

Then it's called CPPM P=pressed CPRM R=recordable

something to read:

http://www.4centity.com/docs/doc_request_thanks.html

And have you ever seen any pressed disc DVD with this flag? As I said, I have never encountered a disc which indicated CPPM or CPRM. I assume if I had, it would have not played on one or the other of my drives but I am still not sure if CPRM being checked is good or bad. Also, just because CPRM is checked does that mean anything in relation to CPPM?

Sorry to be so obtuse, but I just have never seen this protection related in any way to pressed DVDs in any source.

[Fugitive]

Originally Posted by chas0039

And have you ever seen any pressed disc DVD with this flag? As I said, I have never encountered a disc which indicated CPPM or CPRM. I assume if I had, it would have not played on one or the other of my drives but I am still not sure if CPRM being checked is good or bad. Also, just because CPRM is checked does that mean anything in relation to CPPM?

Sorry to be so obtuse, but I just have never seen this protection related in any way to pressed DVDs in any source.

Well i found some threads, one is also DVD Video Madagascar, also a typical diagnostic is: original plays in your standalone livingroom dvd player, but not in your PC,
or the copy does play in your PC but not in the standalone,
It's a long chain of factors: (old) dvd reader, the DVD media (only use plus type) and the burner (should be one of the pre minus dvd recordable type)

[Fugitive]

I have to correct something i posted earlier,
Somehow, a disc recorded on a -R -RW (only) dvd video recorder has some keys "locked" onto the unique ID of that
(first recording) disc i guess, if you could read the .VOB's
in a other CPRM drive, (but has some functions of CPRM switched off i guess) the new dvd disc burned with these files , wil not play in a standalone DVD player, although the files played on the PC

In short: it all is very tricky i'm afraid all new drives have the CPRM feature but only for minus media ,
This protection on pressed media (CPPM) is a different story, and i hope "plus" recordable media will block this function... "the knife cuts both ways" i guess, if they want to sell media and hardware....

[Portmac]

Please use this thread to discuss CPRM.

[Fugitive]

I hope this structure of the "thread"doesn't become too complicated....the subject itself is already tricky to comprehend (for me too)
I guess the protection functions CPPM and CPRM work hand in hand with eachother I don't know yet how far the CPPM protection is having it's influence, also on plus media ?
CPRM seems to have it's reach only over minus media,
i guess because it's the media that mostly complies according
to the original DVD video "book" specifications aka DVD consortium.
Using PlextoolsProXL 3.07:
With the PX-740 from Plextor, with the 1.01 firmware,
some information can be read, from a disc recorded in DVD video-recorder, that only can use -R and -RW media for recording, with the 1.02 firmware in the PX-740 the drive is still CPRM compatible but now it can read the complete DVD video disc, and make an image to make multiple disc copies from, but all these discs are still not seen by the MS Windows Operating System.

btw. trying to make a disc of the image using a +R type of media, fails...

btw2. The CPRM function is also designed to work on SecureDigital memory cards, or transferal over a Firewire or iLink connection, also the protocol is ATA friendly but the designers say this will not be used as such....?
You can do a (Goolge) search for your self on the CPRM subject, but you will not get happy doing this
Old read and burn hardware seem to be the most safe option to defeat CPPM/CPRM.
The hardware Manufacturer is free to build (or not) in this CPPM/CPRM function, unlike the MacroVision protection,
which looks much the same, in it's mechanics..

[igrec]

Sorry... my first post has been placed in the "read first" thread by mistake...

This issue seems quite important to me. I'm a french freelance journalist and a reader alerted me on a problem with CPRM.
I've just posted a note on my blog : http://www.casualtek.com/index.php?/archives/94-You-like-DRM-Youll-enjoy-CPRM-!.html
I invite to share your experience there, for the french speaking people. I'll do my best to translate the most interesting comments.

[Fugitive]

I just tried to respond there also, but i guess i have to register there also, to place any responses, i guess you better link them to this part of CdFreaks, because i guess i have to repeat what i've already said here....

[igrec]

I don't know if you're the one called "Eric" who answered but there's no need to register to post comments on my blog. Anyway, here's my last comment on the matter :

According to the docs from the 4C Entity, the promoters of CPRM, device AND media must be CPRM compliant and the content is ALSO encrypted.

I added a pic extracted from the 4C Entity CPRM Base 1.0 (Introduction and Common Cryptographic Elements) document in my note, on my blog. This pic seems to confirm that content is encrypted with a key make from keys read from the media and the drive.

[Fugitive]

Thanks, yes i discovered that, and have placed already some posts, also placed an alarming link there concerning CPRM > ATA specs: http://www.theregister.co.uk/2001/02...full_coverage/

an other experiment, using an other drive that's also CPRM compatible, works fine and seems no problem at al, putting a CPRM "tagged" disc in (disc was recorded on minus DVD video recorder) this drive, Windows sees all files, so i copied
the VIDEO_TS map onto my pc's hard drive, and burned these onto a plus media dvd r , disc is identified in dvd standalone player as dvd-video but gives black picture.
and fails to accept any command of the infrared-remote.

[igrec]

Firsty of all, after reading a bit more the 4C docs, I come to think that AV content tagged with CPRM is not necessarily encrypted - don't ask me why.
Then, I did a little experiment with the protected disk that's in my possession at the moment : I put in a DVD/HDD standalone recorder from Panasonic, a really new one (still on the store shelf . The recorder agreed without a problem to copy the protected movie to its hard drive and then to copy it back to a blank DVD-RW disk and also to another blank DVD-RAM disk. This is driving me crazy...

[Fugitive]

Originally Posted by igrec

Firsty of all, after reading a bit more the 4C docs, I come to think that AV content tagged with CPRM is not necessarily encrypted - don't ask me why.

correct, CPRM is different layer of protection... but maybe connected to different features, like switching off the reading of the file-system > there's no disc in drive...
btw. this disc can't been seen by Windows ?

Originally Posted by igrec

Then, I did a little experiment with the protected disk that's in my possession at the moment : I put in a DVD/HDD standalone recorder from Panasonic, a really new one (still on the store shelf . The recorder agreed without a problem to copy the protected movie to its hard drive and then to copy it back to a blank DVD-RW disk and also to another blank DVD-RAM disk. This is driving me crazy...

Maybe this Panasonic standalone doesn't have the CPRM feature switched on, or isn't at all present ! The manufacturer is not requered by law to build in CPRM.
but it can be a legal safeguard for the manufacturer,
if "things" get tight...
btw. i now realise something else, sometime ago i bought a
new standalone dvd-player, Philips, because it had the new
HDMI connection, (for LCD & Plasma screens) at home, it could not play most of my dvd r movies, which i captured
with a box, (Canopus ADVC100) only few on different media (Dual layer) did play, (pressed media also) but Dual Layer wasn't in the specs. given in it's manual, the store received a second player which they tested for me with my discs, also not much luck, so i they kept this player, and i got my money back, maybe this is related, i think now.. but i captured with a firewire box, so i don't think a tag/flag survived it in the avi file which was converted to the dvd format, so, this could be the same like you're tranfering your miniDV homemovie by iLink/Firewire to dvd, and you could not play it on a dvd standalone player with a HDMI connection....?(i used the analog video output)
The next step of protection? the new standalone hardware can't play the old previous generation of dvdr video's ?
pressed media will still be no problem...