[linux-audio-user] Cactus Data Shield copy controlled cd's

[Ross Vandegrift]

On Wed, Jul 02, 2003 at 04:43:23PM +0100, Daniel James wrote:
> It ripped and duplicated with no problems whatsoever, which leaves me 
> with three theories:
> 
> 1. The warning is a bluff
> 
> or
> 
> 2. Some CDs were pressed with the anti-copy technology, others weren't
> 
> or
> 
> 3.  They were going to press the CD with Cactus or whatever (when the 
> booklet copy was written) but changed their minds for some reason.

Hmmm, now I'm extra interested in going home this evening and seeing if
the rip finished successfully ::-).  I know it wasn't Cactus that was
used on my audio disc - I actually thought of that and tried to mount
it, but couldn't find an iso9660 filesystem.  And just in case it was
buried in some weird session, I had cdrdao extract the TOC and verify
the layout was consistent.  Just one session of audio.

Everything on that CD was correct, except Q Sub channel CRC codes.

If that indeed is some kind of copy protection, it's absolutely the
worst idea I've ever heard of, since that data is used to error
correcting data on a CD (see semi-recent thread on CD error correction
for more info).  I'll bet one scratch turns that sucker into a
coaster...

(Which ironically, makes me want to be able to burn backups more than
ever!)

-- 
Ross Vandegrift
ross at willow.seitz.com

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He has it pierced.                It is a Holey Wholly Holy Holy-Water Cannon.
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