VideoHelp Forum
+ Reply to Thread
Page 1 of 2
1 2 LastLast
Results 1 to 30 of 33
Thread
  1. Member
    Join Date: May 2004
    Location: New Zealand
    Search Comp PM
    I am a bit of a newbie to this, but I am trying to decide on a a Hard Drive DVD recorder to buy. There are a few that I can afford and like, bit I have been told a few worring things about CPRM. Specifically, my cable provider can apparerently set "record once flags" and if my recorder is CPRM compliant then this means that I can only archive to (expensive) DVD RAM disks, or to (maybe?) CPRM compliant -RW disks, which then can't be played in my older non-compliant DVD players or my laptop etc. I understand that SKY in the UK is already doing this, and therefore it is likely that other providers will sooner or later as well.

    The models I have looked at all seem to have CPRM, based on the downloaded manuals. Can I:

    1. buy a good HD-based DVD recorder that does not include CPRM (and if so which models);

    2. buy any hardware (like you can for macrovision) to strip out CPRM commands; or

    3. use my PC to convert CPRM encoded disks to standard uncrippled DVD format disks that will play in most gear - if so, what tools will "decrypt" CPRM encrypted disks and turn them into standard DVDs.

    This is the sole remaining impediment to me buying a recorder. Sorry of the question is too trivial for any of the experts, but this newbie would be grateful for any advice that would stop me spending a significant sum buying a crippled lemon.
    Quote Quote  
  2. Originally Posted by Chopmeister
    Can I:

    1. buy a good HD-based DVD recorder that does not include CPRM (and if so which models);

    2. buy any hardware (like you can for macrovision) to strip out CPRM commands; or

    3. use my PC to convert CPRM encoded disks to standard uncrippled DVD format disks that will play in most gear - if so, what tools will "decrypt" CPRM encrypted disks and turn them into standard DVDs.
    This is a very important topic and I'm surprised that no one even bothered to comment so far. First, let's get the facts straight. CPRM compliant means that the recorder will respond to the copy flag embedded in the incoming source by CGMS(Copy Generation Management System).

    Generally there are three types of flag, "Copy Always", "Copy Once", and "Copy Never". As you can tell, most commercial DVD movies have "Copy Never" embedded in addition to Macrovision, and that's why standalone DVD recorders cannot copy commercial DVDs. Some cable programs are broadcast with embedded "Copy Once" flag and can be recorded on either HDD, DVD-RAM or DVD-RW in VR mode, but not on DVD-R. If recorded on HDD first, then it can be transfered to DVD-RAM or DVD-RW in VR mode, and the original copy on HDD would be erased. As you may have noticed, all DVD Forum-sanctioned recorders are CPRM compliant and there is no way to get around it (although some +R/RW recorders may). Also the CGMS copy flag affects only recording, not playback ability, although VR mode playback compatibility is quite limited.

    There are of course ways to defeat CGMS, and one of them is to use the Zorrila Video Filter mentioned in the following link:

    http://www.avsforum.com/avs-vb/showthread.php?t=529686

    The above link also has very detailed discussion on CGMS copy flag and its impact on standalone DVD recorders.

    In summary, whether CPRM becomes an issue mainly depends on the video content you record has CGMS copy flag or not. If it does, then there are ways to circumvent it, although not cheap.
    Quote Quote  
  3. Member
    Join Date: Nov 2004
    Location: Canada
    Search Comp PM
    My question is the REVERSE of defeating the CGMS protection mode(s):

    Is there a commonly availble computer program that I can TURN ON THE "COPY NEVER" CGMS flag?
    Quote Quote  
  4. Originally Posted by mbextreme
    Is there a commonly availble computer program that I can TURN ON THE "COPY NEVER" CGMS flag?
    If you read the above link, you''ll notice that someone else asked a similar question, and the video filter could do to that effect, at least in theory, by using "Copy Once" option. But probably not by a computer program yet, because we are talking about analog source signals here, or commonly referred as CGMS-A and A means analog.

    BTW, If you want to add "Copy Never" flag in the first place, you may as well get the license to do that from CGMS patent holder.
    Quote Quote  
  5. Syngery

    I don't believe that most VCR recorders or a DVD recorder like the LiteOn/ilo, when hacked, will respond to CPRM. Is this wrong?

    If a DVD olayer is used first, in conjunction with a DVD recorder, in series or other, to a TV will the CPRM flag be in effect .
    Quote Quote  
  6. Member edDV's Avatar
    Join Date: Mar 2004
    Location: Northern California, USA
    Search Comp PM
    Syngery or others,

    How do you detect CPRM encryption on a cable or sat feed if you are not using a DVD recorder? Does it show up in the analog S-Video feed or just on HDMI? Also, is the flag resolution specific (e.g. 480i, 480p, 720p, 1080i)?
    Quote Quote  
  7. Originally Posted by LCSHG
    I don't believe that most VCR recorders or a DVD recorder like the LiteOn/ilo, when hacked, will respond to CPRM. Is this wrong?

    If a DVD olayer is used first, in conjunction with a DVD recorder, in series or other, to a TV will the CPRM flag be in effect .
    All VCRs and LiteOn/iLo recorders are not CPRM compliant, so they don't respond to the copy flag of CGMS. Most people, however, seem to be confused by CGMS-A and Macrovision (ACP). LiteOn/iLo hacked firmwares disable Macrovision, not CGMS-A copy flag. The document prepared by Macrovision has a nice summary on different copy protection methods on commercial DVDs:

    http://www.macrovision.com/pdfs/Preserving-an-effective-DVD-Copying-System_0303.pdf

    Please note that the copy flag is generated during the D/A conversion stage in a DVD player, and then output through its analog jacks (be it composite, S-video or component output), and any CPRM compliant recorder will block the signals no matter what. This is why you'll never see any installation guide recommending daisy chaining a DVD player with a DVD recorder.

    Originally Posted by edDV
    How do you detect CPRM encryption on a cable or sat feed if you are not using a DVD recorder? Does it show up in the analog S-Video feed or just on HDMI? Also, is the flag resolution specific (e.g. 480i, 480p, 720p, 1080i)?
    CGMS-A copy flag is in the field blanking interval on line 20 or 21 (NTSC) and with the Widescreen Signalling data (WSS) for PAL/SECAM. So in theory, a simple software implementation should be able to check the existence of copy flag and its status. The newest DVD recorders from Pioneer provides this information as part of their on-screen display. As mentioned before, CGMS-A only exists in analog signals, and CGMS-D is for digital signals. Not sure how CGMS-D is implemented, but CGMS-A is resolution independent for sure.
    Quote Quote  
  8. Synergy

    Thanks for the Info. As I understand it the LiteOn/ilo, hacked or unhacked, will not respond to any CPRM flag.
    I can see that any CPRM compliant recorder will respond placed anywhare in the system.
    Are there other recorders that are non-compliant.

    Thanks again
    Quote Quote  
  9. Originally Posted by LCSHG
    Are there other recorders that are non-compliant.
    Since all recorders with DVD-RAM and/or DVD-RW in VR mode are definitely CPRM compliant, your best bet is to look for +R/RW only recorders although most of them are not HDD-based.
    Quote Quote  
  10. Synergy

    Good Info
    The ILO DVDRHD04, with 80gb HDD, will burn +R/RW. The LiteOn 5045 differs basicly in having a 160gb HDD and can burn + or - R/RW disk. they can play many DVD or CD modes' As, non complaint, they should be a plus.
    Quote Quote  
  11. Member
    Join Date: Mar 2002
    Location: Milwaukee, WI USA
    Search Comp PM
    Originally Posted by Synergy
    All VCRs and LiteOn/iLo recorders are not CPRM compliant, so they don't respond to the copy flag of CGMS.
    Are you absolutely sure about this? I just got a LVW5045 (manufacture date Jan 2005) and in the Copy section of the manual there is a note "You canít use the One Touch Copy function to copy a title if any part of the title is copy-once protected."
    Quote Quote  
  12. Member
    Join Date: May 2005
    Location: USA
    Search Comp PM
    What you need a a device that allows you to control the CGMS process.
    You can set the CGMS command line to any of 3 different modes.

    1. Copy Always
    2. Copy Once
    3. Copy Never

    There is such a device out there but I am not at liberty to discuss it on this forum.
    Quote Quote  
  13. Originally Posted by Bondiablo
    I just got a LVW5045 (manufacture date Jan 2005) and in the Copy section of the manual there is a note "You canít use the One Touch Copy function to copy a title if any part of the title is copy-once protected."
    First, thanks for the info. My previous comment was mainly addressed to non-HDD based models since those were the ones most people discussed. Second, the LVW-5045 still allows users to record "copy once" material to either HDD or DVD media directly, however it doesn't allow people to make a digital copy (as one touch copy function does) of the same material simply because it is not "CPRM compliant". A CPRM compliant recorder would only allow "copy once" material be recorded on either HDD, DVD-RAM or DVD-RW in VR mode (Japan currently also sells DVD-R VR media for the same purpose). When the material is transferred from HDD to removable media, the copy on HDD would be erased. The LVW-5045 basically just does the minimum to stop the machine from making multiple copies instead of truly CPRM compliant. You can just bring the copy to a PC and copy away.
    Quote Quote  
  14. Member
    Join Date: Mar 2002
    Location: Milwaukee, WI USA
    Search Comp PM
    Ok, I think I understand what you're saying about it not being "truly compliant". The downside seems to be it's compliant enough that if you ever did record a broadcast which contained the copy flag to the HD you couldn't then copy it to a disc?

    In general is CPRM likely to be as easily defeated with firmware hacks as macrovision and region coding has been?

    PS: The original poster was asking about HD models.
    Quote Quote  
  15. Originally Posted by Bondiablo
    PS: The original poster was asking about HD models.
    Yes, I know. But my comment you quoted was directed to LCSHG. If the statement from the manual was true, the LVW-5045 would be able to one touch copy "copy never" material, but not "copy once". Isn't that ironic?
    Quote Quote  
  16. Member
    Join Date: Mar 2002
    Location: Milwaukee, WI USA
    Search Comp PM
    Yes, if you take it strictly as printed, it's pretty stupid. Also, that note only appears in the One Touch Copy section and specifically says "You can't use One Touch Copy...", the section on copying between DVD and HDD from Easy Guider has no such note. The only other reference to copy once in the manual is under trouble shooting playback "Discs recorded with copy-once material cannot be played on non-CPRM compatible players." and there is no mention of copy never.
    Quote Quote  
  17. Member
    Join Date: May 2004
    Location: New Zealand
    Search Comp PM
    Thanks for the help so far, but not having much luck in the hunt. So far I have managed to rule out Pioneer and Panasonic HD models, as I have downloaded the manuals and they are explicit about supporting CPRM. The panasonic is doubly ruled out as it will only transfer CPRM recodrings to RAM, which nothing else I have will read, whereas the Pioneer will at least use -RW (but, I gather, it requires some sort of "special" -RW media?).

    However, I have made some progress. Update on issues/questions is as follows:

    1. Not being in the US the range of gadgets available is limited (however, no DMCA....Yay) and I need something for PAL not NTSC. There is a shop near me that sells a little remover that claims it will remove "up to level 4 macrovision". I am a bit confused as some of the web discussions are contradictory - can one of the regulars with greater technical knowledge advise what the "levels" of macrovision are, and whether "up to level 4 macrovision" means that it will remove CGMS/A? If so, no CGMS signal component means that CPRM ceases to be an issue and I can buy a recorder.

    2. The newest Cyberlink PowerDVD is advertised as able to play CPRM discs on PCs. This means that it must be possible to read the disc and decrypt in software. This inspires me with hope - does anyone know how much about this. If it's possible to transfer recording to CPRM crippled, I mean enabled, discs then re-master to a standard DVD that will play in laptop or old non-CPRM standard DVD machine etc, then issue has also largely gone. Is there any software like DVD Decrypter that will do this?

    Anyway, thanks for assistance so far, and looking forward to any further discussion.
    Quote Quote  
  18. Member
    Join Date: Mar 2002
    Location: Milwaukee, WI USA
    Search Comp PM
    The liteon might still be your best option. It occurred to me after I signed off yesterday that those only 2 mentions of copy once in the manual maybe related. If the liteon is non compliant then it wouldnt be able to play copy once material and if it can't play it, it obviously cant copy it.
    You canít use the One Touch Copy function to copy a title if any part of the title is copy-once protected.
    Discs recorded with copy-once material cannot be played on non-CPRM compatible players.
    If anyone has an idea how I can test the liteon I'll post back the results, though I'm in the US and only have basic cable so I'm not sure anything I get even uses the copy flag yet.
    Quote Quote  
  19. synergy

    Just to clarify [whew]

    You say that the LiteOn /ILO are not CPRM compliant and therefore do not recognize the CPRM flag.
    A DVD compliant recorder placed in the system will not record A never CPRM flag.
    A DVD non-compliant recorder placed in the system will ignore a CPRM flag and record.

    Will the recorded program also have the CPRM flag? If it did, Why would the recorded program not play on another player?

    This is for real time recording [Not copy]
    Quote Quote  
  20. synergy;

    For info and further clarification

    I have a ILO DVDRHD04 with 80gb HDD. If this unit is CPRM non-compliant, Why can I not play a CPRM disk and record to the DVD or copy to the HDD than to the DVD and play the DVD in another player. This is really the same question as before.
    Quote Quote  
  21. Originally Posted by LCSHG
    If this unit is CPRM non-compliant, Why can I not play a CPRM disk and record to the DVD or copy to the HDD than to the DVD and play the DVD in another player.
    I finally got a chance to read the Lite-On 5045 manual, and the statement that "Discs recorded with copy-once material cannot be played on non-CPRM compatible players." appeared in the "troubleshooting section" seems to be more of "cover its ass" than anything meaningful. Since the Lite-On 5045 itself is non-CPRM compatible, does the statement mean that the 5045 cannot play back its own recordings with copy once flag? Generally if you can record it, then of course you can play it.

    One possibility I can think of is that if DVD-RW media with CPRM certification are used for recording materials with copy once flag, there may be some possibility of incompatibility. Lite-On is too cheap to pay licensing fees to be CPRM-compliant, and I really doubt other than its self-imposed no digital transfer between HDD and DVD, there would be any other consequences for now.

    There must be some Lite-On owners who have recorded some HBO or Cinemax cable programs, so far I haven't heard any Lite-On users complaining about CGMS-A related problems, so I'd assume it's not a problem yet.
    Quote Quote  
  22. In my understanding, copy protected (macrovision or CPRM) video signals are handled in the following way by standalone DVD recorders:
    - Non-CPRM-compliant recorders like DVD+RW recorders don't record these video signals.
    - CPRM-compliant recorders like DVD-RW recorders do record these video signals in CPRM-compliant recording modes (-VR mode) on CPRM-compliant DVDs, if allowed. But then they record it encrypted. If non-CPRM-compliant recording modes (DVD Video) or non-CPRM-compliant (old) DVDs are used, they don't record these video signals.

    Together with the decryption process in a -VR compatible playback device, it is controlled, if an additional copy is allowed in the output signal. Also, the encryption/decryption takes into account the serial number of the CPRM-compliant DVD medium, so that creating 1:1 copies with a PC makes no sense.

    So with copy protected video signals (copy once) you have the choice:
    1) no recording (+VR or video mode),
    2) recording CPRM-encrypted (-VR).
    Quote Quote  
  23. Originally Posted by joeg04
    In my understanding, copy protected (macrovision or CPRM) video signals are handled in the following way by standalone DVD recorders:
    - Non-CPRM-compliant recorders like DVD+RW recorders don't record these video signals.
    For the last time, Macrovision and CGMS-A are two different methods of copy protection, and they work in different ways.

    Since HBO/Cinemax has included "copy once" flag in all their broadcasting and also "copy never" flag in their pay-per-view channels:

    http://www.hboarchive.com/to/cgms_a_affiliate_letter.pdf#search='HBO%20CGMSA'

    http://www.hbo.com/corpinfo/cgmsafaq.shtml

    I'm sure subscribers of HBO/Cinemax could tell more about their experiences with CGMS-A on their DVD recorders.

    Edited: I didn't notice that the letter was dated in 2004. Unless HBO/Cinemax delayed thier implementation, so far I haven't heard complaints from most DVD recorder owners.
    Quote Quote  
  24. Banned
    Join Date: Jul 2001
    Search PM
    I was scared to buy a dvd recorder because of this CPRM issue. I read about it on HBO's site and was afraid I wouldn't be able to record anything. I bought the Pio 220 and in it's manual, it also talks about the CPRM. What's funny is, I'm subscribed to both HBO and Cinemax, but I can record anything I want with the 220s. Does the Line-Inputs bypass the protection or something? It's June 05, that information on HBO was from 2004, so I don't know?
    Quote Quote  
  25. Originally Posted by iluvJLO
    I'm subscribed to both HBO and Cinemax, but I can record anything I want with the 220s. Does the Line-Inputs bypass the protection or something?
    Did you use VR or Video mode for recording? Copy once programs are supposed to be recorded only in VR mode, can you also record the programs directly on DVD-R discs? Just curious.
    Quote Quote  
  26. Banned
    Join Date: Jul 2001
    Search PM
    Originally Posted by Synergy
    Originally Posted by iluvJLO
    I'm subscribed to both HBO and Cinemax, but I can record anything I want with the 220s. Does the Line-Inputs bypass the protection or something?
    Did you use VR or Video mode for recording? Copy once programs are supposed to be recorded only in VR mode, can you also record the programs directly on DVD-R discs? Just curious.
    I always use Video Mode, always -R, occasionally -RW. Maybe that's what it is, the VR mode. Never used it before.
    Quote Quote  
  27. Syngery]

    If I understand correctly. Most, if not all -R/RW recorders are CPRM compliant, except for LiteOn which may have compatibility problems.
    [A number of recorders will record to both - and + media, including the LiteOn]

    Most if not all + R/RW ILO or old DVD's are non-compatible

    Is the media itself is encrypted?

    I agree the manuals leave a lot unsaid. The manual for the ILO states nothing about CPRM


    [joeg04]

    Same as above. I agree that 1 x 1 recording on a PC makes no since

    I was under the impression that Macrovision and CPRM are not the same' My ILO is + R/RW and would react to MV. After the hack it did not.

    I'm not sure that I understand you last statement 1 and 2


    -------------------------------------------------------------------

    I have noticed increasing use of CPRM and speed sensitive disks. A growing number, which may not record or even play if, operated over 1 or 2x. This could be the reason why many are having problems on their PC. I would think that the media industry would force compliance on all recorders. We may be forced to to rely on older or existing non-compliant and hacked units at 1 x 1. NOTE that DVD-Decrypter is No More
    Quote Quote  
  28. In the United States, the legislative and regulatory processes are still going through the motions, but it looks like the FCC has given broadcasters a green light to start using CPRM after July 2005.
    Source (near to end of the page):
    http://archive.avsforum.com/avs-vb/history/topic/416794-1.html

    I don't think that HBO/Cinemax are transmitting CGMS-A signals right now. When they start doing that, I think almost every + or - DVD recorder will not be able to record it non-encrypted.

    Originally Posted by Chopmeister
    Is there any software like DVD Decrypter that will do this?
    To my knowledge no ripping SW exists that can decrypt CPRM encrypted videos.
    Quote Quote  
  29. Member
    Join Date: May 2004
    Location: New Zealand
    Search Comp PM
    The research continues.....I must admit that I am becoming more and more irritated by DRM nonsense. Thusfar I have only purchased legit DVDs and equipment, but it is getting so that pirate discs are starting to look like a much better (ie not just cheaper, but same quality with no DRM or region coding etc) alternative to legit product. It is a sad day when the knock-offs are better quality than the originals

    Back to CPRM, I have been advised by a friend in the industry that SKY TV (New Zealand not UK) will enable this once they have transitioned its platform fully from analog to digital. This means that if I want to record TV onto discs that are universally playable, I definitley need a way to deal with this miserable scheme.

    So far, I have drawn a blank on either computer software to decrypt -RW discs with CPRM. (can any of the technical gurus comment on whether the 56-bit C2 (Cryptomeria) cipher has cracked?). Therefore, it appears that my best choice is to strip out the CGMS signal from the video feed before it hits the recorder. I understand that professional time-base correctors that regenerate lines 20 and 21 will remove CGMS-A information from an analog signal. Can anyone provide advice on a good source & model for such a TBC. I need one that will handle PAL, and preferably a New Zealand vendor although importing is not that big of an issue.

    If nothing else, at least the past few months have been educational. In May I knew nothing beyond putting a disc in a player and pressing play. Now I have done heaps of research and learned plenty - a big thanks to the gurus on this board who generously share their knowledge with noobs like me
    Quote Quote  
  30. Have only experienced CPRM on rare occasions with my Pioneer 420. I'm in the UK and was puzzled to sometimes see a Copy Protection warning after recording TV while out for the evening. It wasn't clear at first which programme (I'd left it recording for several hours) had triggered the warning message.

    I was able to make some detailed observations over a period of a few months, and discovered that it had only ever happened on one channel (ITV1) and that the programme that gave the issue was the local news reports! (Granada News - follows the main news for about 5 minutes).

    It turned out that tiny portions of the news programme were not recorded to the hard drive and chapter marks were automatically placed at those points. A clear jump was noticeable on playback. I can't imagine why anyone would want to prevent people from recording the local news - maybe it was part of an experiment to test the use of CPRM signals - presumably a "Copy Never" in this example.

    Would be interested to hear about others' experiences.
    Quote Quote  



Similar Threads