[Reader-list] CD-Audio Protection System

[Menso Heus]

Still, there are ways to work around this, for example play the CD and 
then record the output going through the soundcard (the output 'fixed' 
by my CD-player) to harddisk. This is also a way used to record RealAudio
streams, for example.

Anyway, the question isn't really whether it's hackable or not, I have
encoded my entire CD collection to high quality MP3's so that I don't 
have to get out of my chair and swap CD's anytime I want to play something
and I don't need to borrow CD's from other people in the house anymore
either since I encoded them too... Oh well, since the protection is still
on the clientside it's not something that can't be hacked^H^H^H^H^H^H fixed.

Menso 'when will they ever learn' Heus

On Tue, Jul 24, 2001 at 09:11:23PM +0530, Jaswinder Singh Kohli wrote:
>  The World's No.1 Science & Technology News Service
> 
> 
> 
> Anti-piracy CD system raises distortion fear
> 
> 16:03   16  July  01
> Barry Fox
> 
> Anti-piracy compact discs that cannot be copied by a computer have gone
> on sale in California. The first CD title has already sold 100,000
> copies, but it is causing concern among audio experts because they fear
> that the music may be audibly distorted.
> 
> 
>  Photo: FPG
> The SafeAudio system was developed by Macrovision, a California-based
> company best known for its anti-piracy video systems. The technology
> stops people "ripping" music CDs to create high-quality digital copies
> on a computer hard disc or for downloading to a portable player.
> 
> The system also prevents people creating digital files from the CD to
> swap over the internet or copying music onto a blank CD - although it
> would still be possible to make a poor quality copy by converting the
> analogue output into digital code.
> 
> SafeAudio works by degrading the digital code. The CD will still play on
> an ordinary player or through a computer's speakers or headphones. But
> it cannot be copied. Macrovision says that the changes made to the music
> are not discernible.
> 
> 
> Bursts of hiss
> 
> 
> Macrovision is reluctant to discuss how SafeAudio works, but has told
> New Scientist that it is based on work done by TTR Technologies of
> Israel. Patents filed by TTR describe how a "copy-protected audio
> compact disc" works.
> 
> The patents say the system deliberately gives some of the digital code
> on the CD "grossly erroneous values", adding bursts of hiss to the audio
> signal. In addition, the error-correction codes on the CD, which would
> normally correct such errors, are distorted. So error correction fails,
> leaving tiny gaps in the music.
> 
> When this happens, a consumer CD player bridges the gaps. It looks at
> the music on either side of the gap and interpolates a replacement
> section. A computer does the same when playing CDs for listening.
> 
> But the computer's CD drive cannot repair the digital data going to the
> hard disc. So the hard disc copies nothing, or a nasty noise. TTR says
> the repairs made by a music CD player are not audible. Macrovision has
> improved the TTR system, says David Simmons, managing director of
> Macrovision's British subsidiary.
> 
> 
> Golden ears
> 
> 
> The company says it has spent six months playing discs to consumers, and
> to professional listeners - known as "golden ears" - at two major record
> companies. None detected any distortion.
> 
> An as yet unidentified album with SafeAudio copy protection has also
> gone on sale in California. "There was no increase in return rate or
> complaints," says Macrovision's Heinz Griesshaber.
> 
> But this doesn't placate hi-fi buffs. "It's a dreadful, dreadful thing
> to contaminate the sound deliberately, says Martin Colloms, a British
> hi-fi expert whose columns are syndicated around the world. "We all hate
> piracy but the idea of mucking up the sound of a recording is
> reprehensible. It's like slashing paintings in a gallery to stop someone
> stealing them."
> 
> 
> 16:03   16  July  01
> 
> 
> --
> 
> 
> Regards
> Jaswinder Singh Kohli
> jskohli at fig.org
> ::::::::::::::::::::::::::::::::::::::::::::::::
> The Uni(multi)verse is a figment of its own imagination.
> In truth time is but an illusion of 3D frequency grid programs.
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