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LinuxDVD CSS Decrypt - Source Available 156

Posted by Hemos from the dvd-is-coming dept.
Kazparr writes "This source code was posted earlier today at Livid. Derek Fawcus confirms that this is his decryption routine for the DVD css encoding scheme. Hopefully, LinuxDVD is one step closer. " So, now we've got some source - but how many of the keys do it actually have in there?
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LinuxDVD CSS Decrypt - Source Available More

LinuxDVD CSS Decrypt - Source Available

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  • But what's up with DVD? I know that the MPEG2 video compression/decompression is patented, so there are troubles with that, but what is the reasoning behind encryption? Is it to prevent piracy, or to disallow distribution in certain areas or what? I haven't followed DVD, so I'm not sure *what* the hell the whole story is... can somebody explain what exactly is involved in getting a DVD to play?
  • SSI -- there is the traditional copy protection in DVD that is also found in video tape, as well as region codes, and this CSS encryption. I have looked in the FAQ, but using anemic as a word to describe it would be giving too much credit.

    What are the issues with liViD?
  • Um, I didn't check inside the encoded data, but I did see that the sender was nobody@replay.com [mailto], which sounds kind of anonymous to me. If this is "leaked" code, would it be legal to use it in further work? It might not have a license, or it might be something unreleased, and proprietary.
  • Will it be ready in time for me to view my spanky-new South Park - Bigger, Longer and Uncut DVD when I receive it sometime mid-novemberish? ;)

    Seeing how I've seen most SP episodes for the first time on my 'puter via RealPlayer, it'd be apropos to see the movie for the first time (at home, anyways) on the 'puter too... preferably under penguin power!

    --
    rickf@transpect.SPAM-B-GONE.net (remove the SPAM-B-GONE bit)

  • The guys that designed DVD decided to make it encrypted so that it couldn't be simply ripped like audio off a music cd... but then again it's only a software security scheme. It's only a matter of time before there are rippers and the like so you can pirate just as easily as mp3z. DVD movies may take a bit longer to download, however.

    Does anyone know if you can easily copy video DVDs with a DVD-RAM drive?

    -----
  • Perhaps a more interesting question is: if this is leaked code, is it legal to write different code based on this that does the same thing?

    -----
  • Is this the encryption that hides the raw MPEG2?

    Is this the only form of copy protection? With this code (and, I'd assume (I haven't look at it yet) some wrapper code) could we copy the movie from the DVD onto a hard drive and play it from there with a standard MPEG player?

    If not, what are the things that prevent this?
  • I'm being stupid today... how can you write a decryption code that's different but still decrypts? Duh.

    -----
  • The nice people at cdmediaworld.com can give some
    pointers to at least ripping the trailers.
    By pure coincidence, these very same instructions
    could work on some movies, too ;)
  • If you read through the archives (I'm on the list) you'll see that the code posted is actually the code to DeCSS - a winblows app. But it contains code written by someone else (also on the list), and it was GPL'ed - that code was originally assembler and then turned into C (the assembler was reverse engineered). The legality is a biggy - but the current feeling is now that its out there, its going to take a fair bit to stop it now. Stay tuned.
  • you cant copy a commercial DVD video with a dvd-RAM or a dvd-RW. last i checked, the industrial strength dvd production units are the only things capable of this. they cost arround $15k
  • >Does anyone know if you can easily copy video
    >DVDs with a DVD-RAM drive?

    Should be feasible to duplicate whole disks by using scsi-to-scsi copying of a DVD drive to a DVD-RAM.

    Part-copying no doubt requires proprietary code.

    Nigel

    ---
  • The legality is a biggy - but the current feeling is now that its out there, its going to take a fair bit to stop it now.

    Yes and no. The code is out of the bag, and cannot be put back. However, if it violates copyright (or is perceived to), incorporating it in any application would be the kiss of death as far as distribution goes. If Red Hat or someone was to ship a DVD player containing "liberated" code, they would be opening themselves up to massive legal liability. As such, any code with such a pedigree will remain firmly in the underground, away from the eye of the general public.

  • Re:piracy (Score:1)

    by Anonymous Coward
    Why would you want to copy to DVD-RAM anyway? The 2.6gig discs are $15 and the 5.2gig discs are $25-30. Defeats the purpose for most movies I think.
  • Yep, not an econimical way to pirate a movie. More likely that you'd use this method for backing up DVDs.

    ---

  • Har, Mateys! (Score:3)

    by Christopher B. Brown ( 1267 ) <cbbrowne@gmail.com> on Tuesday October 26, 1999 @04:16AM (#1586926) Homepage
    The reasoning for using encryption is indeed "all of the above."
    • Making copies "is piracy."
    • Using a copy in a jurisdiction in which it has not been licensed to be used "is piracy."

    The consideration that using crypto, and patented crypto, at that, permits constructing protocols similar to Circuit City's (now cancelled) DIVX scheme is gravy...

    Of course, I stand more in the pedantic camp [hex.net] that prefer to use words in the ways they were designed. Thomas Bushnell wrote it well:

    The word ``piracy'' refers to seizing ships on the high seas, where normal social mechanisms of common defense are unavailable, and killing or kidnapping the sailors on board, and then stealing the ships and the goods they carry.

    Piracy is an act a fair bit worse than robbing banks - more is stolen and many more people die.

    Incurring civil penalties for copying software is nowhere near as bad as all that, and using the word ``piracy'' attempts to stir people up into a frenzy of horror.

    This, I think, is a bad thing to do

    In short, it seems to me that the SPA has "hijacked" (hee, hee) the use of the word piracy in much the same way that the term hacker gets used and abused in the media.

  • Re:piracy (Score:3)

    by Sontas ( 6747 ) on Tuesday October 26, 1999 @04:23AM (#1586927)
    CSS is designed to stop the everyday joe from making copies of discs. The authentication (or disc locking) is what really accomplishes that. The data encryption is a second part of CSS as a whole, and it is meant to prevent raw data copying after the disc has been unlocked (since the VOB data is supposed to be always encryped when travelling over an unsecured bus).

    As to making copies with DVD-RAM, not possible unless you have the CSS decryption schemes as part of the DVD-RAM burning software. While you could technically unlock the drive with an external program (to the dvd-ram burning software) and then make a copy of the encrypted data, byte for byte, you still will not be able to copy the disc or title keys without involving special drive commands and CSS authentication in the dvd burning software. Of course, now that the authentication and decryption code is public (and the disc key's likely to be brute forced in a short time with the code), it will be relatively easy to write a program that burns unencrypted copies of the discs to dvd-ram.

  • Re:wait a minute (Score:1)

    by Anonymous Coward
    Well, as a simple (and very lame) example of how to make different code do the same thing, check this out:

    Method 1:

    int y = 0;
    y = x * x + x;

    Method 2:

    int y = 0;
    y = squarexplusone(x);

    (Put whatever code you like in for squarexplusone that gets the job done).

    Same result, somewhat different method.

    Not a great example, but workable. Both use different enough code that I don't think any lawyer could say they are the same. Since decryption is virtually all math, you just need to do the math routines "differently". This is no problem as long as you end up with the same results.

    You can only copyright a way something works, not the result (To copyright the result makes it a patent. Patents on mathematical ideas/results aren't legal everywhere, witness BladeEnc...)...

    But, I'm certainly no expert! So don't thake this message as some form of advice or nothing! :-)
  • Take a look on just about any "warez" site or check out some of the movie rooms on IRC, there have been movie rippers (DVD rippers) around for quite a while. Matter of fact the Matrix DVD rip was being circulated at least a month before it hit the store. With a cable modem or other fast connection it only takes a day or so to donwload.

  • Nice and smelly source code (Score:3)

    by wilkinsm ( 13507 ) on Tuesday October 26, 1999 @04:33AM (#1586930)
    These routines were obviously ripped from a windows based DVD player. CSSAuth.cpp is the interesting file, for it contains the actual CSS key tables.

    IIRC, there is still floating out there one key that is player specific - in other words, the key is different for each type of DVD model player. I think it's just simple lock/unlock routine however, and it should be easily hacked.

    CSS was the major road block before, but not anymore. I guess all they need now is someone to leak the Dolby surround specs.

    Of course, this is probably all very highly illegal, and just by downloading the code I could be in trouble. I think I will delete my copy now...

  • Re:CSS Encryption (Score:5)

    by Sontas ( 6747 ) on Tuesday October 26, 1999 @04:41AM (#1586931)
    Yes this is the encryption that hides the raw mpeg-2 data (as well as AC-3 and subpicture and some navigation information).

    This is not the only form of copy protection involved in DVD playback, in general, there is also regional management (although that is not a real problem now that the css code is available).

    A standard mpeg player will play the data once decrypted, but some discs will be hard to watch due to the use of different camera angles and some other dvd specific features. Not to mention all the navigational features will not be available (interactive menus, playback navigational data, etc).

    The only thing really preventing full playback is not having a public IFO file format spec and some of the dvd specific VOB stream fetures are still relatively unknown publicly (the features are known, how they are implemented isn't). Reverse engingeering those two things will be difficult. Much more difficult than CSS was. Even if someone tries to simply disassemble some working player it will be difficult due to how dense the information provided in the IFO files is and the ways it is used in the player. IT can be done though and I'm sure it will be done, just don't expect it all that soon.
  • However, if it violates copyright (or is perceived to), incorporating it in any application would be the kiss of death as far as distribution goes.

    I'm not sure about that since proving copyright violation would require the offended company to disclose its own source. Having done so in a court of law, the source enters the realm of the public domain (as far as access). Having the original copyrighted source to play with would be fun because then many variations could be played upon it to achieve a new source not substantially similar to the original.

    If the original gets kept behind closed doors, then the copied form being sued about can also get a facelift to keep it copyright free.

    I guess that leaves patents as the main problem... like usual.
  • Important note, there is no indication or evidence suggesting that the encryption methods used in CSS are patented. The methods seem to be protected via "trade secret" and NDA, which suggested it has no patents. Same for the IFO/VOB data formats in the DVD Video Specifications books available from the DVD-Forum under NDA and for-cost licenses. The only patented parts of DVDs seem to be the mpeg-2, AC-3, SDDS, etc encoding schemes.
  • The AC-3 specs are public. ATSC A/52 is the document you want to look for. And there is a GPL'd AC-3 decoder available, created by Aaron Holtzman, for Linux. This is unlicensed though and as someone else pointed out, you will not be seeing it included in a commercialized distribution (or even noncommercial) due to the legal/licensing issues involved. Check out these sites for more info:

    http://www.csh.rit.edu/lsdvd
    http://livid.on.openprojects.net
    http://linuxdvd.corepower.com
  • Not for encryption strength reasons, it's only 40bit and a variant (from what I understand) of DES or RC4.

    IT may be illegal for any kind of distribution whatsoever for copyright and perhaps reverce engineering reasons, however.
  • I would have thought that within six months it'll be more likely that you want to rip the MPEG data to a hard disk. How many people just keep their MP3s on disk rather than bother blowing a CD? Hard disk space is getting cheaper all the time...
  • Just a brainfart:

    Now that we see the light with DVD & Linux--Do you think there is the possibility for someone to code a program to read the DIVX format, and produce a /market/ for the useless DIVX CDs now in circulation?

    -d9

  • Re:piracy (Score:3)

    by mcc ( 14761 ) <amcclure@purdue.edu> on Tuesday October 26, 1999 @05:13AM (#1586939) Homepage
    encrypting the DVDs has no real effect other than causing problems for people who wish to use it legally. what it comes down to is almost security through obscurity.

    The way i see it, there are three types of people who are going to be pirating DVDS, and none of them are going to be stopped by the current "security" methods.

    Random people at home who rent DVDs from a store and make copies. Of course, things will be much more difficult for these people than the days of the late 80s (where you could just go to Randalls, rent a tape and a VCR, and copy off the rented VCR onto your home VCR..). But things won't be more difficult for these people because of CSS encryption; things will be more difficult because of the fact DVDs aren't easily writable. Of course, if these people are willing to settle for second-rate quality, the option of borrowing a VCR and making a tape copy STILL EXISTS! remember: an s-video out port has _no idea_ what happens at the other end. No system will _ever_ be devised where it is more difficult to send the video into a recording device than it is to send the video into a TV to watch it.

    People on the internet who trade around copies of movies. This is pretty much similar to the first one; there's still the fact that the video-out of a DVD player can always be sent to a recording device. Of course, an entire DVD would not be fun to download over the internet, so probably any movies on the internet will be re-encoded at lower quality, making any quality loss caused by not making a byte-for-byte copy of the DVD irrelivant. And after all, there are MPEG-1 versions of movies that are in _theaters_ floating around at warez sites everywhere, and i'll bet a lot of the others come from tapes. I doubt that being able to put keys on DVD-RAMs or whatever will affect this much.

    Big-time piraters, sometimes in third-world countries, which make huge numbers of exact copies and distribute them widely. These people will probably be wanting the "keys", or whatever you're talking about, as they'd want it identical to the original DVD. But these people also will probably not be using an average consumer PC. They'll be making enough money from this that they can afford to use some kind of customized hardware that will do whatever "special drive commands" they want. Even if such hardware doesn't exist at the moment, for the makers of the DVD spec to pretend such hardware will not come into existance the instant there's some amount of money in DVD pirating is just silly.

    I'm pretty sure that if the DVD companies will already be losing the revenue from these people, any money _saved_ by the CSS will be pocket change..

    -mcc-baka
    INTELLECTUAL PROPERTY IS THEFT

  • honestly, i have to say, i personally have not done much looking into DVD encryption and copy protection, but just reading a lot of the posts here, and going over the source that was posted for this program, i am impressed with the sophistication of which DVD was developed. Unlike several other attempts at a 'secure' format, (AKA: mp3, unf*ck.exe, and other easially ripped audio formats), DVD seems to have been very well designed.
  • These people aren't/weren't giving out copies of the actual Matrix DVD (or any other DVD for that matter). These were simply taken by someone having the actual Matrix DVD, playing it on their screen, and using another program to capture that image, or by playing it on their own TV and then getting that image off their TV with their computer. Regardless, they weren't technically ripping the DVD.. They were just making a copy of the move stored on there.
  • These people aren't/weren't giving out copies of the actual Matrix DVD (or any other DVD for that matter). These were simply taken by someone having the actual Matrix DVD, playing it on their screen, and using another program to capture that image, or by playing it on their own TV and then getting that image off their TV with their computer. Regardless, they weren't technically ripping the DVD.. They were just creating a movie from their TV or DVD-ROM playing the movie.

  • Re:not really an anonymous luser (Score:1)

    by Anonymous Coward
    One way around this would be to release a player app which doesn't do AC-3 nor CSS. The player would play MPEGs and unencrypted DVD's with PCM audio tracks. Also allow core plugins and publish the interface.

    Now, Mr. Hacker takes the CSS source and makes a CSS plugin. Mrs. Hacker does the same with the AC-3 code. Both plugins could be found on servers in countries which don't abide by the west's copyright laws, or on "warez" sites. The player application is 100% legal since it has nothing to do with the contaminated code, and the means would be there for those who wish to get full encrypted DVD support.

  • Re:ripping DVD's (Score:1)

    by Anonymous Coward
    you cant copy a commercial DVD video with a dvd-RAM or a dvd-RW.

    No, but in practice with the 1e30 rippers that exists for DOS/Windows, and the miscellaneous work-arounds, you can copy the content of your DVD to any support, including DVD-RAM, DVD-RW, cdrom, or hard-drive. The problem is that the cost of the DVDram support , cdrom, hard-drive, is higher than the cost of the movie. Well not for cdrom, but you have to split and burn six to ten CD, then to change every 20 minutes, or copy all the CDs first to hard disk, etc... which is something that only people with too much time in their hands would do.

  • All this is fine and good for DVD players -- and especially nice for the Linux/DVD convergence -- but what's the outlook for actual DVD copying?

    What's the time frame for, say, being able to buy a PC-DVD-RAM (RW?) player and making a mirror image of the DVD disk?

    I understand that current units cost upwards of 15K. When will this hardware reach the consumer level?

  • Good points. What is refered to as piracy is either copyright violation, or license violation, or just something that pisses the company off.


    What really pissed me off though are things like DVD with support to stop the movie from being viewed in certain areas.

    That's completely without any reasonable justification, and without a legal leg to stand on.

    I support cracking of DVD encryption mainly for this reason.

    (Yes, you could sign a license obligating you to only view the movie in north america, or on mondays, or while nude, but if you don't sign anything agreeing to it, they can't legally dictate your usage.)

  • Re:piracy (Score:1)

    by IQ ( 14453 )
    Ummm because they have KIDS. Kids can deal with video tapes no problem... but CDs and DVDs they tend to toss around like the frisbees that they are and scratch them. DVDs have much better error correction schemes in them than CDs but they also have a much greater density to destroy with the same scratch.

    This is actually a fair use issue. I would like to make a copy of my Yellow Submarine DVD so the kids can watch it without destroying it. And no, I don't want to copy it to VHS. Even a 4 year old can notice the difference between VHS and DVD formats.
  • Of course, if these people are willing to settle for second-rate quality, the option of borrowing a VCR and making a tape copy STILL EXISTS! remember: an s-video out port has _no idea_ what happens at the other end. No system will _ever_ be devised where it is more difficult to send the video into a recording device than it is to send the video into a TV to watch it. Actually a system called macrovision which has existed for quite some years is capable of scrambling a vcr (primarily by messing with it's automatic gain control). This system is mandatory on a DVD player. Usually macrovision doesn't scramble a display device (some projectors are susceptible though, and you might be able to see some artifacts in the top of the frame on some tvs) In europe where many (most?) purchase players modified to play any zone very often also get macrovision disabled.
  • I would suggest that people who want DVD for Linux also start lobbying manufacturers of hardware DVD decoders, such as Sigma Designs who make the Hollywood Plus, for Linux support and drivers.

    HH
  • But the correct usage would be

    it'd be approprié

    "apropros" means "on the subject of"
  • Huh? 15k???? Maybe for a rackmount unit or
    something... but PC DVD-RAM drives start at
    about $370.00... That's for an internal Toshiba
    scsi drive... as for copying DVDs, even with the
    drive it will still be a while... and then there
    are the legal issues... but I'm sure you were
    just referring to making backups of your disks
    ;-)
  • OK, this may sound flippant, but I have to say it: If we don't have all the keys we need, how about getting something like distributed.net going? Someone cabbage together a linux client that takes a shot at brute-forcing the keys used to decode DVDs. I can't think of a better -- and more applicable -- use of my spare Linux cycles.

    Of course, I haven't actually read the DVD spec, so I may be talking out ass.

    -B

  • Yeah, but 'apropos' is a *nix command, 'approprie' will just elict a confused shell error. ;)

    --
    rickf@transpect.SPAM-B-GONE.net (remove the SPAM-B-GONE bit)

  • No no, he/she is talking about movie lenght DVD production units. The things you MAKE movie dvds with.

    I do multimedia devel work and we were looking at getting a devel station, but I desided all we needed was MPEG-1/2 playback and static graphics with navigation - I went with a highspeed local network and XML with MPEG playback links instead ( kiosks and such )
    --
    James Michael Keller

  • CSS is fundamentally flawed in many respects. It looks like something designed by an intern at IBM. Seriously there are things in there that simply make no sense from a cryptography perspective. I won't say anymore as this topic (copy protection) can be legally sensitive in some countries.

    - Aaron Holtzman
  • You're forgetting about Macrovision protection. Most if not all DVDs come with it nowadays. Macrovision protection generates energy bursts that will confuse the autogain circuitry of a VCR, making copy impossible unless you have a compensator of some sort.

    If you rent a DVD and have a normal VCR and a normal DVD player, you cannot make a copy because of Macrovision. If you want to make a copy, you must either purchase a machine that'll supress the Macrovision (often sold as "video quality enhancers"), or modify your player, or have a PC-DVD player with an anti-Macrovision crack.
  • Good demonstration of why i enjoy slashdot so much. If i'm ignorant on a topic, i'm corrected. thank you.
  • Most of the commentary thus far has focused on the aspects of "copying" DVD movies, etc. But from where I sit, the issue of decoding seems much more related to having the ability to install a DVD drive in the PC and play an encoded disk on the computer, but under Linux, not Windows, etc.

    BTW, I do not claim to know anything about DVD other than it has massive storage capacities compared to CD-ROM, so go easy on the flamethrowers, and teach me instead, okay?

    Anyway, here's why I ask. Early next year I will be part of a project involved in the gathering and indexing of large amounts of art (primarily paintings), then publishing it via DVD, similar to how CD-ROM titles are published now.

    While the practical part of me knows the answer (win-doze), the programmer side of me says, if it won't play back under Linux, what's the point? Comments invited...

  • DVD copying (Score:3)

    by aphr0 ( 7423 ) on Tuesday October 26, 1999 @06:48AM (#1586966)
    Many posters here are wondering about cracking dvd keys and copying discs and generally pirating them in various ways. If my meager law knowledge isn't failing me, piracy is illegal.

    My point isn't about piracy, it's about hypocracy. If there is even the hint that someone is illegally trampling on the GPL or something beloved to linuxite hearts, there is an immediate cry of bringing in the law. Is illegaly pirating DVDs more acceptable than illegally taking code from a GPLed program? They are both examples of taking something and using it in ways that are not legal.

    Another semirelated point is the cry of people of "Even if it is commercial, I'll buy it! I want it for linux, open source or not!" But, judging from the immediate reaction of "Let's crack it and take all we can," it seems not many people WOULD pay for much in linux. The few that would actually buy games or apps for linux are far outweighed by the number that would simply pirate it or crack it. It seems to me that many people in the "open source" community don't give a damn about open source. They just want everything they can get for free.

    All of this makes me wonder if companies are influenced by reactions like this. If I were a company pondering putting in the work to release my commercial product for linux, I would definitely think twice before I spent the time and money on porting or rewriting. Yes, I know that piracy is also rampant in the windows world, but just looking at what has been posted thus far, it seems the linux market isn't exactly filled with willing buyers of software and other replicable items. (movies, audio, etc)

    * Please not that I said 'many,' not 'all.' There is a difference.

  • Clearing up some issues (I hope) (Score:3)

    by Rayban ( 13436 ) on Tuesday October 26, 1999 @06:50AM (#1586968) Homepage
    Hopefully this post will clear up some of the misconceptions here. Basically, this package is the reverse engineered version of a program called DeCSS, something which can be used to authenticate with and unlock a DVD player.

    DeCSS will be available under the GPL, but as its source had not been released yet, someone decided to reverse engineer it and make the source public. The author has stated that this puts this new source under the GPL, which has a good outlook for us.

  • Re:DVD disc Copying? (Score:3)

    by Eric Sharkey ( 1717 ) <sharkey@lisaneric.org> on Tuesday October 26, 1999 @06:58AM (#1586969)
    Huh? 15k???? Maybe for a rackmount unit or
    something... but PC DVD-RAM drives start at
    bout $370.00...

    DVD RAM and DVD ROM are different technologies. Not all DVD players can read DVD RAM. (In fact, I believe most cannot.) Not to mention the fact that the drive which you're referring to can only write at a density of 5.2 GB per disk. (2.6 GB/side). The $15K model is needed for writing the standard 18 GB DVD-ROM disks.

  • Re:We need a distributed attempt (Score:1)

    by Anonymous Coward
    It would be overkill.

    Your common Pentium III class computer could brute force the remaining keys in a few days.
  • If region lockouts were a private deal between movie studios and electronics makers (as it started out) I would have little issue with the lockouts as I could legally buy, sell, and trade into about mod chips or pre-modded players. However, come 1/1/00 in the US, the Digital Millennium Copyright Act kicks in and among other things, makes it illegal to sell players that can be "readily modified" to defeat region lockouts or to sell modded units or to sell parts to mod units. Now it's not an industry agreement anymore. Gov't is now enforcing region lockouts. Gov't is telling, under threat of civil/criminal prosecution, that I am to be blocked from hearing the speech (movies) from those in other nations. That to do so is now illegal?!

    -------------------------------------------------- -------
    The line was crossed when the gov't got involved. Now it is officially censorship and can be challenged as a constitutional issue.
    -------------------------------------------------- -------

  • ... will it be implemented cross-platform? An open source DVD player will not only be good for Linux, but for everyone in general (that is, users of other Unices, MacOS and even Windows).

    It really would be a shame if things like this will be implemented Linux-only. Aside from the kernel driver (is that necessary?), porting should not be too difficult...
  • It's not the technology that is right or wrong, it's the uses to which it is put. Most posters here are interested in playing DVDs on their Linux systems. Since it is then intention of the licensees that they be able to play the DVDs that they have bought/licensed, this desire, in and of itself, is not wrong. Cracking the keys may be a way to enable Linux-based playback if the companies won't support our favorite OS.

    The technology, once available, might also be put to wrong uses. Piracy in any form is wrong, whether it takes place on a Windows system with a CD or DVD ripper or on a Linux system.

    Even then, there may be justiafiable uses for a CD/DVD ripper. The concept of "fair use" under copyright law allows you to make additional copies of copyrighted material for your own use. Copyright holders (and supporters of UCITA) may wish to get rid of fair use, but we don't have to cooperate.
  • The MacroVision "scrambling" is quite easy to remove. Depending on the age of your VCR, you may be able to simply bypass the AGC controls all together -- if you are feeding a quality signal into the VCR, the AGC is not needed.

    Plus, there are TV's and VCR's specifically designed to remove it. I have a VCR that will record MacroVision intact with zero effect to the video quality. (Let the cable company MacroVision every channel; it won't bother me.)

  • Government always mucks things up. This "region code" thing is really a way the DVD producers shoot themselves in the foot by not allowing their goods to be marketed equally around the globe, thus reducing potential sales, and thus profits. The amount lost to "piracy" is miniscule compared to the great gains possible by having one world standard (which DVD has: note there's no "NTSC" or "PAL" DVD's: the translation to NTSC or PAL is done on the player from a standard disc).

    Having government enforce a private agreement does make it censorship. Those weird alien folks who call themselves "politicians" back there in the District of Criminals need to get a life. :-)

  • As the other reply indicates, the DVD player implements Macrovision BUT the DVD must turn it on. Most US made DVDs of US made movies enable this circuit, it costs about 2 to 4 cents per disk to licence its use.

    I believe the DVD FAQ has more information on this:

    [videodiscovery.com]
    http://www.videodiscovery.com/vdyweb/dvd/dvdfaq. html

    As others have commented, it does screw up some projectors, but some companies avoid Macrovision simply because it reduces image quality a little bit. I understand the desire to reduce the number of illegal copies, stuff like this tends to eliminate legal copies, such as those buying DVD, not having a player yet, so they want a short term VHS archive copy.
  • Quote from the Livid FAQ: "The CSS code here is NOT enough to decrypt DVD's. This code mearly unlocks the DVD drive and will allow the data to be sent to a decoder (hardware or software)." However,: "Since the Zoran 36710 decoder card decrypts the sectors in hardware, we can have a fully functional DVD playback system for Linux."
  • You are making the classic mistake of confusing one group of people with another group of people. One group says "P", the other says "not P", and then (to both groups at once) "oh you guys are so hypocritical".

    My advice is to deal with people on an individual basis.

  • The author has stated that this puts this new source under the GPL, which has a good outlook for us.


    Actually it doesn't. If this were true, Microsoft could claim the copyright on Samba and decide what kind of licensing it would carry. The act of reverse engineering and reimplementing makes the result the property of the person doing the reverse engineering.

    Lacking any other copyright in the code, it would be smartest for the Livid team to wait for a verifiable version of such code to show up.

    -sw
  • Well, the reason I believe that it's under the GPL is that it was bundled with the css-auth package (GPL'd by the author). I can't remember my GPL very well.. does this bring the reversed engineering source under the GPL as well?
  • But it contains code written by someone else (also on the list), and it was GPL'ed - that code was originally assembler and then turned into C (the assembler was reverse engineered).

    Actually the Algorithm was determined from inspection of the x86 assembler, and then a new implementation of that algorithm was written. This C implementation is wahat was GPL'ed.

  • But it contains code written by someone else (also on the list), and it was GPL'ed - that code was originally assembler and then turned into C (the assembler was reverse engineered).

    Actually the Algorithm was determined from inspection of the x86 assembler, and then a new implementation of that algorithm was written. This C implementation is what I then GPL'ed.

    The legality is a biggy

    Not at all - an individual expression of the CSS authentication algorithm may be copyrighted, but the alogrithm itself cannot be.

  • Okay, guys, I know that not everyone can afford a real DVD player, a Dolby Digital (and maybe DTS) receiver, and five *good* speakers. Not everyone who can afford it has the time, desire, or physical space. But some of us do.

    If I want to watch a movie on DVD, I take it to my nice home theater. Computer playback is great for impoverished students, space-challenged homes, and travelers with notebooks. But there's no way a general purpose computer could ever have better picture size and sound quality than a dedicated player can, given the same price.

    I'm far more interested in DVD for plain data storage. Imagine having *one* DVD-ROM filled with your favorite Linux distribution, both in source code form and pre-compiled for several different architectures. Directly bootable for x86, indirectly bootable for PPC/SPARC/etc. Easy enough.

    Or use it to store a huge number of high-quality standard image files. Clip art? Porn? We'll have to let the market decide.

    The PC I'm using now has a DVD-ROM drive, but Linux sees it as CD-ROM only. I wonder when that will change.

  • which DVD has: note there's no "NTSC" or "PAL" DVD's: the translation to NTSC or PAL is done on the player from a standard disc

    Hmmm...then what does the "NTSC" mark on most of the Region 1 discs mean? :-)

    I was actually confused by this the first time I noticed it on a DVD, as I was under the same impression you are. Perhaps you (or someone else) can clarify this for me?
  • We don't want to pirate DVDs, we just want to play them.

    Evil people have gone out of their way to make it hard to make us play them.

  • I follow the Livid mailing list and the faq answer you are refering to does NOT refer to the code posted yesterday on the mailing list. CSS is composed of two parts, the first is unlocking the drive and the second is decrptying the datastream. The faq refers to previously released code that did the former. The new code does the latter.

  • Basically, this package is the reverse engineered version of a program called DeCSS, something which can be used to authenticate with and unlock a DVD player.

    No it's not it's the original source to DeCSS. I've got a copy of that. If it was reverse engineered then the CSSauth.cpp file wouldn't be identical to that in the "proper" DeCSS source and remarkably similar to the code in my CSS authenticion [demon.co.uk] package.

    DeCSS will be available under the GPL, but as its source had not been released yet

    Actually the source accidentally escaped when DeCSS was originally published.

  • Let me see....

    I bought a DVD-encore player from SoundBlaster for a few hundred dollars. I bought DVD movies from BestBuy at $15-$30 a piece...

    Now I'd like to play the DVDs on that drive using Linux, but creative does not have the software. So someone writes one by reverse engineering something else. What law am I breaking? I am playing a paid-for DVD on a paid-for player. There may be something illegal to this, but there *definetely* is nothing immoral to this. That's what it boils down to.

    Now, if I used this reversed engineered code to rip DVD and resell them, that would be wrong and immoral. But that is not the case.
  • If I'm not mistaken, all DVDs are actually encoded as 24 fps 640x480 _progressive_scan_ movies. The dvd player then converts this to 30fps (using 3:2 pulldown... nevermind) _interlaced_ crap-ass NTSC. This is what makes DVDs so cool: they aren't limited by NTSC interlacing or anything like that. If you get a projector and a progressive-scan DVD player (or just usemonitor output, if your computer is fast enough), the output looks better than NTSC. true progressive 640x480 supposedly looks as good or better than a 16mm print, with digital accuracy.

    And, with anamorphic DVDs (720x480), you can get even more pixels. DVDs will actually looks better in the future!

    (Note: This is what I understand, and it might be wrong. is it?)

  • LinuxDVD CSS Decrypt - Source Available (Score:4)

    by firebird ( 32164 ) on Tuesday October 26, 1999 @08:51AM (#1586992)
    Derek Fawcus confirms that this is his decryption routine for the DVD css encoding scheme.

    No actually what I said was that the authentication code was mine and that since it was GPL'ed, this whole source release is now GPL infected.

    Derek Fawcus

  • As I understand it, the crypto stuff only applies to DVD movie discs. If you are just going to publish a standard DVD-ROM, then it should work under Linux with no problems.

  • When CD-R was new, blank cds costed like $10, which made copying music CDs a rather pointless excersice. Obviously, that is no longer the case.

    And besides, it won't be long until storing a library of 4 gig movies on your HD is no big deal.

    -
    /. is like a steer's horns, a point here, a point there and a lot of bull in between.
  • Reading DVD Rom is no problem whatsoever in linux. They behave, as far as I can tell, like a normal CD Rom drive. (read: To use my new pioneer DVD Rom in Linux, I didn't have to make single modification.) (it replaced my aging cdrom drive)

    The issue here is decoding and playing actual DVD Movie titles. Accessing the raw files is not a problem. It's the decoding of the video/audio files that is the issue.
  • Yep, you're wrong. From http://www.dvdreview.com/html/dvd_myths.html

    8. DVD is a worldwide standard.
    In addition to regional codes that can be used to prevent playback in different areas, DVD uses different formats for
    NTSC or PAL playback. Almost no US players can play PAL DVDs. Most European players can play both PAL and NTSC
    TVs, but only on a 60-Hz-capable PAL TV or a multistandard TV. Most DVD-equipped computers can play
    both NTSC and PAL discs.
  • Doesn't change the fact that it's cheaper to buy a new copy of the movie than to make a DVD backup of it.

    Which is as it should be. Warner's home video seems to understand this, marketing most of their films fairly cheaply, and selling older titles at a major discount. My local Tower's has a bin full of Warner's titles at $12 US.

    The jerks at Disney on the other hand, after trying to pin all their hopes on the DIVX "charge them for every viewing" method are finally selling regular DVDs. But they are trying to keep the prices as high as possible.

    When DVDs were first released, virtually every title was discounted to $19 US. The prices have been creeping back up to $24 US, $34 US and even $49 US.

    This is insane...VHS has always been more expensive to make. Except in rare instances like the Sony Sprinter, VHS is duplicated at 1:1 speed in a room filled with thousands of professional duplication machines churning out a 2 hour film in 2 hours. Stamping out a DVD has nothing but advantages for the studios...and still their naked avarice is the controlling factor.

  • How many people just keep their MP3s on disk rather than bother blowing a CD? Hard disk space is getting cheaper all the time...

    True, but blank CD-Rs are cheaper still, and they're more portable. I have my MP3s on ten CD-Rs. I can easily take them between home and work, and the CDs are set up so that they'll autoplay like an audio CD when you stick 'em in the drive (well, they'll do that on Win9x anyway).

  • Of course, if these people are willing to settle for second-rate quality, the option of borrowing a VCR and making a tape copy STILL EXISTS! remember: an s-video out port has _no idea_ what happens at the other end. No system will _ever_ be devised where it is more difficult to send the video into a recording device than it is to send the video into a TV to watch it.

    Actually a system called macrovision which has existed for quite some years is capable of scrambling a vcr (primarily by messing with it's automatic gain control). This system is mandatory on a DVD player.

    Devices are available (or used to be available) that would filter out Macrovision. I have one that I bought a few years back...it only works on composite video (not S-video), but I don't have anything that accepts S-video input anyway. Radio-Electronics magazine even published the design of one of these "Macrovision strippers" sometime in the mid-to-late 80s, so you could build one yourself if you wanted. (It might even be possible to modify the design to work with S-video...would the nasty stuff be hidden in the luminance signal or the chrominance signal? Maybe you could get by with just diverting the appropriate signal through this box and let the other signal go through without modification.)

    Another option for computer-based DVD is something like Remote Selector that disables Macrovision on hardware-based DVD decoders. I use this with my Dxr2 instead of the abovementioned Macrovision filter.

  • If I want to watch a movie on DVD, I take it to my nice home theater. Computer playback is great for impoverished students, space-challenged homes, and travelers with notebooks. But there's no way a general purpose computer could ever have better picture size and sound quality than a dedicated player can, given the same price.

    You're mistaken. A hardware decoder card in even a fairly slow PC does a better job of playing a DVD than even the most expensive stand-alone player.

    I have a dedicated home theater with a 10' projector and 5 speakers. I chose to build a PC from spare parts, a cheap DVD-ROM drive and a hardware decoder. This is showing me a progressive scan image that is worlds better than the 3:2 pull-down, interlaced junk that every stand-alone player puts out. I honestly would not have a dedicated player in my theater.

  • But I think they're still stored on the disc progressively... There's a reason there are these wildly expensive progressive-output dvd players coming out now. Are they just undoing the interlacing?
  • Not automaticaly. It gives the author of css-auth the right to sue for breach of his license, which can be remedied if the copyright holder of the bundled code applies the GPL to it, or if the copyright holder pays him some money, etc.

    Thanks

    Bruce

  • Not so fast, Derek! (Score:3)

    by Bruce Perens ( 3872 ) <bruce@perens.com> on Tuesday October 26, 1999 @10:52AM (#1587009) Homepage Journal
    Derek,

    If you are the copyright holder of the authentication code, and if your code was integrated into this product, not just "bundled", you now have the right to sue the other copyright holder for breach of your license. An outcome of that may be that the other code is GPL-ed, but infection is not automatic.

    This is probably moot, as they plan to GPL it anyway.

    Thanks

    Bruce

  • Here are several different implementations of the squarexplusone() function (sxp1, for brevity) -- note that I assume x >= 0:

    implementation 1 (duh):

    int sxp1(int x) {
    return x * x + 1;
    }

    implementation 2 (obvious, if inefficient):

    #include "math.h"

    int sxp1(int x) {
    return (int)rint(pow(x, 2)) + 1;
    }

    implementation 3 (the same, but more evil):

    #include "math.h"

    int sxp1(int x) {
    return (int)rint(exp(2*log(x))) + 1;
    }

    implementation 4 (eschew multiplication):

    int sxp1(int x) {
    int r, sum;
    for ( sum = r = x ; r > 1 ; r-- ) {
    sum += x;
    }
    return sum + 1;
    }

    implementation 5 (same thing ... scheme, anyone?):

    static int _sxp1(int x, int r) {
    return r ? ( x + _sxp1(x, r - 1) ) : 1;
    }

    int sxp1(int x) {
    return x + _sxp1(x, x - 1);
    }

    I could go on, but I think I'm having more fun than is good for me...

    Berlin-- http://www.berlin-consortium.org [berlin-consortium.org]
  • I tried to cut too many corners. :/

    It should be:

    static int _sxp1(int x, int r) {
    return ( r > 0 ) ? ( x + _sxp1(x, r - 1) ) : 1;
    }

    Berlin-- http://www.berlin-consortium.org [berlin-consortium.org]
  • FWIW, the more "canonical" approach to #5 would be:

    static int mult(int x, int r) {
    return ( r > 1 ) : x + mult(x, r - 1) : x;
    }

    int sxp1(int x) {
    return _sxp1(x, x) + 1;
    }

    Okay, okay, I'll stop now...

    Berlin-- http://www.berlin-consortium.org [berlin-consortium.org]
  • Yes, VHS is more expensive to produce AFTER mastering, but the whole process of DVD mastering is more expensive. IN going to digital in movie theaters and in home DVD players, the movie industry has to spend much more on the whole filmmaking process to make the clearer, cleaner digital movies worth it.
    However, DVD's better get cheaper, and not go the route of music CD's, which have kept getting more expensive as the technology matured, even though the price of producing a CD is virtually nill now...
  • Well, I can put 10 or so albums on a single CD that costs me less then a buck, and then have portable music I can take to work, school, home, etc..
    Quite a bargin I believe...
    Now I can just hope for a small CD based mp3 player to debut commercially..
  • This is a common type of argument used to reduce freedoms. "If you were a good person, you wouldn't WANT to do X, so we can take it away and you shouldn't complain."

    Legal penalties exist to punish people who do things 'we' decide are 'wrong'. This is why we don't have to take away the ability to do these things, because people who do them can be dealt with appropriately.

    If it was illegal to decrypt these disks except in a licensed player, or to publish decryption information, or even to attempt it, as many companies seem to be lobbying for, then we would lose the ability to do many things that should be legal as well.


    Cracking the encryption, being able to copy the movie as a big MPEG file, is an essential step in pirating the movie, but it's also an essential step in viewing the movie in the way that YOU want.

    I support the freedoms that let people break the law (or encure civil penalties) because these freedoms are essential for us to live the life we know an deserve.
  • I looked at the Sigma Designs Web site (sigmadesigns.com) and found that there is a link for suggestions.

    it is: arthur_bao@sdesigns.com

    I sent Mr. Bao the following suggestion via email:



    Date: Tue, 26 Oct 1999 16:54:04 -0400 (EDT)
    From: Timothy Lord
    To: arthur_bao@sdesigns.com
    Subject: Interested in Linux Support for hardware DVD decoders

    Dear Sir:

    My name is Timothy Lord. I enjoy DVD movies (what a great format!), but I presently must use an external player rather than one installed in one of my PCs, because I prefer Linux or another free operating system to those made by Microsoft.

    I urge you to consider developing (or helping fund the development) of drivers for your company's products under Linux or other UNIX-like operating systems. There is a large market of potential buyers who would be interested in buying hardware DVD decoders, if they could run them without switching operating systems.

    For evidence, I would suggest looking at the site www.slashdot.org;whenever DVD is mentioned on Slashdot, there is an active discussion, and many posters want to know "WHen can I watch my new DVD movies under Linux?!"

    If you can sell a DVD player that comes packaged with drivers which let it work under Linux (especially if you are the first company to do so!), you will have an appreciative audience -- the goodwill generated by the support for Linux shown by some other companies (such as ATi) has been fantastic.

    Thank you for considering this suggestion; good luck with your products and company!

    Sincerely,

    Timothy Lord
    timothy@monkey.org

  • so, what if source is released once not under GPL, and then the author decides to GPL the code later? i would think that i can just take the uninfected code from the first release and freely use that. it seems that the question of whether or not it *will* be GPL'd is moot.

    sh_
  • You aren't allowed to release the GPL section as part of it if the entire thing isn't GPL'ed.

    If you don't abide by the GPL license, you loose all rights to the source including redistribution.

    --
  • The GPL AC-3 decoder is called 'ac3dec' and is available at http://ess.engr.uvic.ca/~aholtzma/ac3/ [engr.uvic.ca]. It supports Linux, Solaris, etc.

    The Dolby Digital AC-3 specs are on that site as well.

    --
  • Slightly off-topic, but partitons are not limited to 2GB in modern linux at least(on both the 2.0.37 and 2.2.13 kernels I run, I have larger partitions).
    I am not as sure about the 2GB file limit, although I know in 64bit ports it has been removed, I think it is still a limitation in 32bit Linux, though I remember hearing something about a database company contributing a patch for this and think it is in the 2.3.x series... Not quite sure though...
  • Let me see...

    Case #1

    Suppose person A held up a bank and stole $1000.
    Suppose person A dropped $15 while running away.
    Suppose you picked it up and donated it to charity

    Just because you do something "good", "right", or "moral" with the $15 doesn't make it "moral"...

    So why would it be moral to use something (the DVD decoder) that was obtained in a possibly immoral
    (violated patent/licensing rules) fashion?

    Case #2

    To be more clear, suppose there is a piece of code (say regexp library) that is BSD licenced (old
    style). Suppose you have BSD unix so you are "kosher" for using the code. However, you have a
    piece of non-compliant GPL code that wrongfully stole the code and embedded it in an application
    (but slightly modified). Is it moral for you to use this non-compliant package even though you
    sort-of have a licence to use the code (because you are running BSD-unix)? Or by supporting this
    "immoral" application, you are committing an immoral act by using it? What if you didn't know
    where the code came from? What if you suspected the code came from an illegal source?

    I'd be interested to see people's answer to this one... at least be honest and say it's not as
    simple a dillema as some people make it out to be...

  • Re:Not so fast, Bruce! (Score:3)

    by Bruce Perens ( 3872 ) <bruce@perens.com> on Tuesday October 26, 1999 @03:49PM (#1587030) Homepage Journal
    If you include someone's GPL code and they don't like it, you either negociate an out-of-court settlement with them or you go to court and the judge decides. In either case, you may get financial damages, you may get some other mitigation such as the other code having the GPL applied to it, you may only get the other party to stop using and distributing your code. Or a combination of those. But none of this is automatic. It takes the negociation of two parties or the intervention of the court.

    The odds are that if you admit your mistake, stop distributing, and pay a royalty for what money you've already made during the infringement, you will not lose the rights to your own code or have the GPL applied to it.

    Don't worry about draconian terms (forfeit your firstborn child, etc.) because judges won't enforce them.

    Thanks

    Bruce

  • Well, if you made money from it, I could still come after you for a royalty. But yes, you can not use the GPL to force people to free up their code. That's because the "viral" nature of the GPL is a fiction. People who speak of it as some sort of infectious thing don't know how IP laws work.

    Thanks

    Bruce

  • This was his response to my suggestion about Linux support for DVD decoding under Linux with their hardware:

    We are working on supporting Linux. I will let you know when there is any update.


    Thank you for taking the time to send us your thoughtful suggestion. I will forward this to the product manager and engineers to keep on their
    to-do-list.

    Thanks again for your time, patience and support.


    That sounds good to me!

    timothy


  • So I guess what you are saying if someone "reverse engineered" a piece of code, and put it into some
    software even though the original author of the code probably didn't want anyone to do that, you
    feel no moral obligation to not use this "reverse engineered" piece of code even though it has been
    "co-opted" for use against the wishes of the original author...

    Well, that's a interesting interpretation of how a person might go about stealing GPL code and put it
    into the public domain (which might be distributed against the GPL license) and still sleep at
    night...

    Gee I could have downloaded the GPL code anyways for free so I guess I have the right to do
    whatever I want with it... I don't feel bad at all... Just because I use the package and I don't
    violate the GPL then just because this package exists and many other people to violate the GPL
    that's not -my- problem... I find it convenient so I'm not gonna stop using it...

    You may find this a "minor" moral transgression in the scheme of things (which is ok in my book), but
    to say it's completely moral doesn't seem to be entirely honest. This is a bit extreme, but this
    moral dillema is not too different from using immoral nazi medical research. The only thing
    different is degree and if you think violating the CSS group's rights is moral. Or that somehow the
    FSF/GPL rights are somehow more sacred than the CSS group's rights or rights or nazi prisoners...

    You might counter that nobody got hurt, but would you change your mind if the company who's private
    key got compromized to make DeCSS gets slapped for a $1M fine, lays off all their employees and goes
    bankrupt? I'm not saying this will happen, but it could...

    I'd like to see proof of this "reverse engineering" before this gets release under the GPL...
  • I don't think I'm missing the point completely... The way I see it, it's the same as...

    1. the intent of the GPL is to keep software free by forcing derivative software to also be free.

    2. he downloads a public domain piece of SW that (illegally) incorporates GPL code. The code
    is open source, but professes to be public domain unencumbered by the GPL. He still follows the GPL
    rules for this piece of software (distributes source, sends the copyleft notice), but others do not.

    3. therefore, even though the software is in violation of the GPL (because it professes not to
    be restricted by the GPL), he has no problem with using it since in other circumstances he has the
    right to use the same subroutines in the software...

    A very simple argument, and quite sound. A perfect framework to look the other way when the
    GPL is being violated... Is this what we call moral these days?


  • no, I just hope people would be more moral than that... sigh...

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