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BMG Backs Down Over Copy-Protected CD
An anonymous submitter sends in: "As reported by The Register, on the 5th of November, BMG released the UK's first copy-protected CD (more information on Eurorights and Fat Chuck's). It uses Cactus Data Shield by Midbar Tech, which aims to prevent CD to CD or digital CD to Minidisc copying, along with converting to MP3, but may have other bad side effects."
The submitter continues: "There were complaints from fans and many took their CDs back or wrote to the record company and record shops. Their hard work seems to have paid off since Virgin Megastores has responded to a complaint from one of their customers and said that BMG has set up a helpline to allow people who bought the corrupt version, to exchange it for a real one. Virgin and HMV will also be bringing in new stock of uncorrupted CDs. The message was originally posted to the Official Natalie Imbruglia Bulletin Board (free registration required) in the "White Lies" and "Lillies vs Cactus" threads, but several threads containing complaints against Cactus Data Shield have been deleted so the email has been mirrored on the Free-sklyarov-uk mailing list. This is very good news, but more work needs to be done. Hopefully with pressure from the public other retailers will follow Virgin's example. Also record companies need to be made clear that selling copy protected CDs, that infringe on the public's rights, is not acceptable. The battle isn't over until no new CDs are shipped in these formats so if you find a CD that is copy-protected then report it on Eurorights for the UK, or Fat Chucks for elsewhere, take it back to the shop, and let them, and the record company know your feelings on the issue."
Stolen from http://www.uk.eurorights.org/issues/cd/overview.sh tml:
The most recent format that's come to light is the Cactus Data Shield from Midbar. The earlier German tests also came under the name of Cactus, but it appears that Midbar's protection technology has developed since then. Like SafeAudio, this new method corrupts the audio signal on the CD. However, the method used is different. In this case blocks of audio are replaced with blocks of control data. A normal CD player ignores the control data and fabricates the sound of that block using its error recovery circuitry. Once again, the blocks must have been carefully chosen so that the sound is not disrupted significantly. Again, reliability of the CD will be affected. When the CD is copied using a computer or CD-to-CD copier, the control blocks are interpreted as audio, which means that the manufacturer can insert whatever sounds they wish into a copied recording, even sounds designed to damage speakers.
"If he thinks he can hide and run from the United States and our allies, he's sorely mistaken." Bush on bin Laden
With the EUCD (European Union Copyright Directive), that is starting the process of getting incorporated into national laws, BMG would have the law on it's side and copying CDs with this kind of protection would be a crime, even if it was under a "fair use" clause. This is the main problem with this law, for the first time any company can restrict how you use its products. Until now copyright law only affected copying, distributing and modifying the product.
In the USA the won't probably do a recall because all this is legal under the DMCA. Providing "fair use" became optional.
Mac OS X/iMac-DVD: Track 1 doesn't play, rest okay (ripping not tested)
Mac OS 9/iBook-DVD: All tracks play and rip okay
MiniDisk: Refuses to record digitally
PS2: Track 1 won't play, rest okay
Linux: Tried extracting tracks (cdparanoia), disk is not always recognised first time. Out of 12 tracks, only track 3 extracts cleanly - all others hang with read errors (probably work better with a better drive than mine).
Windows: Runs a custom MP3-player from the CD, playing data from a 30Mb data file of unknown format (according to a report I've just had).
This could be a good wake up call for Joe Six-Pack, if only for the PS2 having problems with the disk. If the industrys can pass it off as "Something that only affects Home Hackers", they can keep the attention down. When it starts going wrong in mass produced home appliances that could never be used to copy it, maybe the public will pay attention?
But this has been said before, last time it was about in-car CD players not playing protected disks...We can only hope public intolerance is cumulative, and people will start to vote with their wallets, because that's the only way things like this will stop.
I bought Codename Outbreak last week, and the copy protection on that game doesn't allow my (Original) CD to be read when the game boots...Have to "Hang" the system to kick start it every time. The site's forum is full of people with the same problem. Copy protection in itself I don't mind, if people want to get paid for their efforts I don't see why they shouldn't. But when you can't use the product you just paid for, something's gone awry.
I don't think I'm very happy. I always fall asleep to the sound of my own screams.
Of particular interest is the section:
During duplication the CD encoding circuitry merely sets the P-channel=0 while recording to the data are, and therefore the P-channel setting of portion 60 is ignored. Thus, during playback, the substituted audio data portion 58 is provided to the digital-to-analog converter as normal data, resulting in audio distortion and potentially damaging the output circuitry. (emphasis mine).
They also don't seem to be as confident about audio quality as I would have hoped:
Thus, the substitute audio data portion 58 of FIG. 4B is ignored, and instead an interpolation, substantially equivalent to the original portion 50 of FIG. 4A, is output, thus resulting in little or no net difference in audio quality between the corresponding track port 44 and 52 of FIGS. 4A and 4B (again empahasis mine).
If I buy music, I want the CD to be as close as possible to the real thing, not with any noise added.
Steven Murdoch.
web: http://www.cl.cam.ac.uk/users/sjm217/
The presence of the ability to play the damned things is more what we're talking about here. A CD that threatens to trash your speakers if you simply try to play it on some CD players isn't just questionable -- it's broken
Sometimes boldness is in fashion. Sometimes only the brave will be bold.
They don't. The cd has a data track that contains *very* poor mp3 copies of the songs in a single big file and a crappy player.
Oh so I get it an audio CD player is analog but a CDROM is digital... Bzzzt.
Well, you're right, but you've missed what's going on:
The audio standard (for CDs) trades longer playing time for reduced ability to absolutely correct errors. (There's less redundant data.) The digital standard (for CD-ROMs) includes more check-data with lower absolute capacity. (You can't get a CD's worth of .WAV files on a CD-ROM.)
The playback/reading methods are also different. When you load a music CD and press play, the resulting digital datastream is routed to an onboard decoder chip which converts the digital audio data to analog and sends it to the drive's audio outputs. The decoding process designed to tolerate all but the most severe errors: First it corrects any errors that it can, then attempts to conceal any errors that it can't correct. Only if the concealment doesn't work does it fail, and then only for a limited time. (A 1/2-second burp on a 79-minute disc shouldn't prevent the rest of the disc from playing.)
When you're reading a data disc, (or when you're using a rip program that reads the audio CD as digital data), you use the drive's internal data-validation routines. With data, you (usually) don't want errors that can't be fixed to be quietly concealed (think tax tables with wrong numbers in them, or a one-byte error in an .EXE), so the drive is set up to choke if it runs into an error that it can't correct.
What the Cactus and related systems try to do is add just enough bad bits to the data stream that CD-ROM drives will choke when reading the disc as data, without adding "detectable" degredation when the same data is processed as digital audio through the audio decoder chip. Problem is, that assumes that all players have the same tolerance for bad data (unlikely), that the all players will react to bad data in the same way (so you can predict what corruption is "safe"), and that all listeners have the same standards for what's "undetectable" (don't make me laugh). Plus the fact that intentionally corrupting the data makes a less robust disc; one more likely to fail if things like fingerprints, scratches, or dirty laser lenses further degrade the signal. Not pretty!
Yes, there should be a way around this. IIRC, cdparanoia does something like what you suggest. I don't think you'd want to implement this at the driver level, though, unless it was coded to allow you to switch the correction routine on and off. Because, as noted above, there are times you need to know that the data's bad and can't be fixed (or has been fudged).
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