Slashdot Mirror

Section (2-4-4) talks about MediaCloQ and how to remove the protection. Section (2-4-3) explains what is known about Macrovision's stuff, and what the options are for working around it. Nearby sections talk about Cactus Data Shield and the protection used on the Michael Jackson single.

(Shameless plug warning: I wrote the FAQ.)

See this item for details on the protection. In short, they've screwed up the disc's table of contents so the CD-ROM drive can't make heads or tails of it. Audio CD players just ignore all the gunk. You can trivially work around the problem by reading the disc as a series of blocks.

A related story on news.com is a "news.com special report" on the subject of copy-protected audio CDs.

The "Cactus Data Shield" brand has been around for a while, but this appears to be an updated version.

The original implementation tweaked out the table of contents on discs, making it appear that the disc was only 30 seconds long (28 after you subtract the mandatory two-second pregap). This allowed most CD players to play the disc, because they ignored the lead-out value, but CD-ROM drives got confused. Unfortunately for BMG, some Philips CD players did pay attention to the value and refused to play the CDs. The scheme was abandoned.

This updated scheme uses an entirely different approach, one that could be worse than the Macrovision stuff. If it works as well as they claim, it would have to produce distortion on all digital outputs -- otherwise their claims of defeating audio CD copiers wouldn't hold.

I'd love to get my hands on one of these. I tried to get some of the German discs with the old Cactus protection, but the import I got from Amazon was, of all things, a copy on CD-R media.

One thing to note: the article did not say that damaging CDs were released (shame on slashdot for going for hype instead of fact). It said that they *could* be released. Highly unlikely they ever would.

As far as Ministry CDs not playing, they probably did something bizarre to be cute and inadvertently caused problems. Artists will occasionally do strange things with CDs, e.g. Nine Inch Nails putting 99 tracks on their "Broken" CD, most of which are only one second long. (Red Book says mininum track length is 4 seconds.)

For a list of "odd" CDs, see http://www.turbine.com/oddcd/.

For details about the current audio CD copy protection stuff, see http://www.cdrfaq.org/, sections 2-4-2, 2-4-3 2-4-4

The "Cactus Data Shield" brand has been around for a while, but this appears to be an updated version.

The original implementation tweaked out the table of contents on discs, making it appear that the disc was only 30 seconds long (28 after you subtract the mandatory two-second pregap). This allowed most CD players to play the disc, because they ignored the lead-out value, but CD-ROM drives got confused. Unfortunately for BMG, some Philips CD players did pay attention to the value and refused to play the CDs. The scheme was abandoned.

This updated scheme uses an entirely different approach, one that could be worse than the Macrovision stuff. If it works as well as they claim, it would have to produce distortion on all digital outputs -- otherwise their claims of defeating audio CD copiers wouldn't hold.

I'd love to get my hands on one of these. I tried to get some of the German discs with the old Cactus protection, but the import I got from Amazon was, of all things, a copy on CD-R media.

One thing to note: the article did not say that damaging CDs were released (shame on slashdot for going for hype instead of fact). It said that they *could* be released. Highly unlikely they ever would.

As far as Ministry CDs not playing, they probably did something bizarre to be cute and inadvertently caused problems. Artists will occasionally do strange things with CDs, e.g. Nine Inch Nails putting 99 tracks on their "Broken" CD, most of which are only one second long. (Red Book says mininum track length is 4 seconds.)

For a list of "odd" CDs, see http://www.turbine.com/oddcd/.

For details about the current audio CD copy protection stuff, see http://www.cdrfaq.org/, sections 2-4-2, 2-4-3 2-4-4

The "Cactus Data Shield" brand has been around for a while, but this appears to be an updated version.

The original implementation tweaked out the table of contents on discs, making it appear that the disc was only 30 seconds long (28 after you subtract the mandatory two-second pregap). This allowed most CD players to play the disc, because they ignored the lead-out value, but CD-ROM drives got confused. Unfortunately for BMG, some Philips CD players did pay attention to the value and refused to play the CDs. The scheme was abandoned.

This updated scheme uses an entirely different approach, one that could be worse than the Macrovision stuff. If it works as well as they claim, it would have to produce distortion on all digital outputs -- otherwise their claims of defeating audio CD copiers wouldn't hold.

I'd love to get my hands on one of these. I tried to get some of the German discs with the old Cactus protection, but the import I got from Amazon was, of all things, a copy on CD-R media.

One thing to note: the article did not say that damaging CDs were released (shame on slashdot for going for hype instead of fact). It said that they *could* be released. Highly unlikely they ever would.

As far as Ministry CDs not playing, they probably did something bizarre to be cute and inadvertently caused problems. Artists will occasionally do strange things with CDs, e.g. Nine Inch Nails putting 99 tracks on their "Broken" CD, most of which are only one second long. (Red Book says mininum track length is 4 seconds.)

For a list of "odd" CDs, see http://www.turbine.com/oddcd/.

For details about the current audio CD copy protection stuff, see http://www.cdrfaq.org/, sections 2-4-2, 2-4-3 2-4-4

The "Cactus Data Shield" brand has been around for a while, but this appears to be an updated version.

The original implementation tweaked out the table of contents on discs, making it appear that the disc was only 30 seconds long (28 after you subtract the mandatory two-second pregap). This allowed most CD players to play the disc, because they ignored the lead-out value, but CD-ROM drives got confused. Unfortunately for BMG, some Philips CD players did pay attention to the value and refused to play the CDs. The scheme was abandoned.

This updated scheme uses an entirely different approach, one that could be worse than the Macrovision stuff. If it works as well as they claim, it would have to produce distortion on all digital outputs -- otherwise their claims of defeating audio CD copiers wouldn't hold.

I'd love to get my hands on one of these. I tried to get some of the German discs with the old Cactus protection, but the import I got from Amazon was, of all things, a copy on CD-R media.

One thing to note: the article did not say that damaging CDs were released (shame on slashdot for going for hype instead of fact). It said that they *could* be released. Highly unlikely they ever would.

As far as Ministry CDs not playing, they probably did something bizarre to be cute and inadvertently caused problems. Artists will occasionally do strange things with CDs, e.g. Nine Inch Nails putting 99 tracks on their "Broken" CD, most of which are only one second long. (Red Book says mininum track length is 4 seconds.)

For a list of "odd" CDs, see http://www.turbine.com/oddcd/.

For details about the current audio CD copy protection stuff, see http://www.cdrfaq.org/, sections 2-4-2, 2-4-3 2-4-4

..I just wait for the copy protected CD's to be played on the radio, then I tape em on 120 minute cassettes.. Wow- I'm time-shifting.. can you dig it? This radical technique even gives me the ability to fast forward past commercials and irritating DJ's talking loudly about 'less talk, more rock' ..Woo hoo.. I'm livin' in the future now..

And what will you do when those CDRs begin to degrade over time?

What good would a CD-ROM be if you couldn't pull data off a CD? Repeat after me: Audio CD's are just 1's and 0's.

LOL. Not quite. Audio data is arranged COMPLETELY differently from other data (files, etc) on a CD. Pulling audio data from a CD, pulling regular ISO 9660 data from a CD, and having the CD read audio data and run it through the DAC and out through an analog connection are three ENTIRELY different opreations from a hardware standpoint.

"It is true that audio CDs use all 2352 bytes per block for sound samples, while CD-ROMs use only 2048 bytes per block, with most of the rest going to ECC (Error Correcting Code) data. The error correction that keeps your CDs sounding the way they're supposed to, even when scratched or dirty, is applied at a lower level.

All of the data written to a CD uses CIRC (Cross-Interleaved Reed-Solomon Code) encoding. Every CD has two layers of error correction, called C1 and C2. C1 corrects bit errors at the lowest level, C2 applies to bytes in a frame (24 bytes per frame, 98 frames per block). In addition, the data is interleaved and spread over a large arc. (This is why you should always clean CDs from the center out, not in a circular motion.)"
--from this cool faq

Like I said... a ton of CDROM drives used to NOT support DAE. DAE is an extra feature purposely included by hardware manufacturers. From a technical standpoint they could EASILY stop including this feature (if laws forced them to do so).

"Don't worry about the hardware manufacturers of CD-ROM's, worry about a new format to replace CD-ROM's that carries copy protection bullshit in with it"

Well... I agree with you 100% there... you're right... like you say they're already building all sorts of digital protection into new digital TV's... I just wonder WHY they never went after (in a legal sense) the DAE feature on CDROM's. Made sense to me... not that that would be right... it just seems like the logical step of attack. *shrug*


http://www.bootyproject.org

See this entry in the CDR FAQ.

Subject: [7-17] What's the difference between "data" and "music" blanks? (2001/03/12)

"Consumer" stand-alone audio CD recorders require special blanks. See section (5-12) for details. There is no difference in quality or composition between "data" blanks and "music" blanks, except for a flag that indicates which one it is. It's likely that "music" blanks are optimized for recording at 1x, since anything you record "live" is by definition recorded at 1x. You don't have to use "music" blanks to record music on a computer or "professional" stand-alone audio CD recorder, but nothing will prevent you from doing so.

The "music" blanks are more expensive than the "data" blanks because a portion of the price goes to the music industry. The specifics vary from country to country.

Some manufacturers have on occasion marked low-quality data discs as being "for music", on the assumption that small errors will go unnoticed. Make sure that, if you need the special blanks, you're getting the right thing.