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Copy Control

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Copy Controlwas the generic name of acopy preventionsystem, used from 2001 until 2006 on several digital audio disc releases byEMI GroupandSony BMG Music Entertainmentin several regions (Europe, Canada, United States, and Australia). It should not be confused with the CopyControl computer software copy protection system introduced byMicrocosm Ltdin 1989.

Copy Control logo

Several types of protection existed. While basically intended as a means of copy-protectingcompact discs,Copy Control discs cannot properly be referred to as CDs because the system introduces incompatible data, making the discs non-compliant with theRed Bookstandard for audio CDs. The system is intended to preventdigital audio extraction( "ripping" ) from the protected discs, and thus limit thefile sharingof ripped music. The techniques used are:

  • Multisession (Blue Book) information is included which effectively hides the audio tracks from mostCD-ROMdrives;
  • Error-correctioncodes for the audio data are corrupted, which may introduce audible errors to ripped copies.
  • The data area of the disc usually includesDRM-restricted copies of the audio content, for which a player only exists on the dominant PCoperating system,Microsoft Windows.

In the Netherlands, the record labels Sony and Universal experimented with copy control until 2004.EMIkept using it until June 2006, when they dropped it.

In the United States,Universal Music Groupexperimented with copy control on a few soundtracks in 2001 and 2002, but abandoned it afterwards;Warner Music Grouphas only used it in Europe on such releases asRed Hot Chili Peppers'Greatest HitsandMadonna'sMusic.As of September 2006,Cactus Data Shield,theMacrovisiontechnology behind Copy Control, is no longer listed as a product on Macrovision's website and has completely been abandoned in countries such as Australia.[1]

A December 2006 issue ofBillboardmagazineannounced that EMI had decided to abandon Copy Control worldwide. Until then, it had been unclear whether EMI had completely abandoned it; there was no press release.

Background

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The Copy Control protections were devised in response to thefile sharingand casual CD copying that has become commonplace in recent years, allegedly causing the music industry significant losses, or "ungained" revenues. Neither issue was particularly relevant when the CD standard was introduced in the early 1980s, and thus, unlike the more recentDVDs,the CD standard specifies no inherent form of copy protection or otherdigital rights management.Copy Control is one of a number of attempts to apply copy protection on top of the CD standard, but since it is merely a modification of the already unrestricted standard that must still yield usable results in most CD players, the efficacy of the system varies significantly. Nevertheless, EMI's labelling of some Copy Controlled discs attempted to override consumers' statutory rights with the disclaimer "except for defective product resulting from the manufacturing process, no exchange, return or refund is permitted".[2]

Circumvention

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A Copy Control disc will appear as a mixed-mode disc, with audio and data content. Under Windows, inserting the disc will usuallyautorunan audio player utility, which plays the DRM-protected audio files provided. This can be temporarily disabled by holding down theshift keywhile inserting the disc on Windows XP and earlier, users of Windows Vista and 7 may simply choose not to run the DRM content.

The ability to extract the CD-Audio tracks is otherwise largely dependent on the disc drive used. The first obstacle is the "fake" Table of Contents (ToC), which is intended to mask the audio tracks from CD-ROM drives. However CD-R/RW drives, and similar, can usually access all session data on a disc, and thus can properly read the audio segment.

The other major obstacle is the incompatible (and technically corrupted) error-correction data. Again, the effect of this is dependent on the disc drive; some drives will be able to read the data without problems, but others will produce audio files with loud pops every few seconds. As a consequence of having faulty error-correction codes, the discs may be less resilient to anything that might cause a read error, such as dust and scratches resulting from normal use.

Copy Control also does not prevent copying a disc by recording it as analog audio through a computer's sound card, which only causes a slight degradation in audio quality. More substantial is the loss in recording speed. This weakness, inherent in all digital copy prevention systems, is known as the "analog hole".As an alternative that does not rely on the" analog hole ", it may be possible to copy the content using a digital link while playing it through a sound card that has a digital audio output.

Usually a CD-R/RW drive will play the disc but with occasional stops (about every 10 seconds) and DVD-R/RW drives will be able to read the data without problems and can be ripped straight to the PC.[citation needed]CD-ROM or DVD-ROM drives in a computer will usually refuse to play the data except in the provided player.

Systems other than Windows can just as easily play Copy Control discs, as many players on Windows are proprietary and respect the copy-restrictions. Similarly, the auto-launchers are only written for Windows and will only ambush Windows users (this can be mitigated by disabling autorun). There is little that can be done to stop a user who is not running Windows or who is using non-Microsoft CD ripping software from ripping a Copy Control disc.

InLinux,Copy Control discs are easily accessed throughcdparanoiaor any other software that uses it, such as theKDE"audiocd:/" service.

InMac OS X,these discs are easily accessed through iTunes and QuickTime (When a CDDA track is dragged to a folder other than the CD, QuickTime automatically converts it toAIFF,which is a lossless PCM format).

Content on the CD extra

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Main article:Cactus Data Shield
CDS-100 or CDS-200
A player and a media file database (a copy of the audio contents in Windows Media). The player will only play the audio contents in the media file database.
CDS-300
A player and the anti-copy program only. The player can ignore the anti-copy program to read the audio tracks. The player allow users to play the tracks, rip the audio tracks asDRM-enabled WMA files and burn CD for 3 times (The player will rip the CD as 320 kbit/s WMA files, then burn the audio on a CD-R, notice that the volume is lower and the quality is worse on the burned CD).

See also

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References

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  1. ^Macrovision - Copy Protection, Software Licensing, and Digital Rights ManagementArchived2006-09-09 at theWayback Machine
  2. ^"Campaign for Digital Rights - Corrupt audio disc information".xenoclast.org.
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