Original URL: http://www.theregister.co.uk/2001/08/01/antirip_cd_system_bypassed/

Anti-rip CD system bypassed

Macrovision's SafeAudio not too safe, apparently

By Tony Smith

Posted in Personal, 1st August 2001 12:41 GMT

Macrovision's SafeAudio technology, designed to prevent PC-owning music fans from ripping CD tracks onto their hard drives, has been bypassed.

Commercial CDs protected by Macrovision's technology went on sale to the public in the US and elsewhere last month, part of a test programme to ensure listeners aren't upset by the company's system.

SafeAudio essentially corrupts the data on the CD. Hi-fi CD players' error correction systems can cope with the bursts of noise added to the music, so the listener remains - allegedly* - unaware there's anything they're hearing anything but a perfect sound reproduction. The error correction system treats the noise as just one more result of the inherently noisy environment, thanks to high disk speeds, grubby disk surfaces and frequent laser mis-reads, that all CD players are. Listen to an audio CD with error correction switched off and you'll hear little more than hiss.

PC CD drives, on the other hand, require the mediation of a controller application, which treats all this extra noise as corrupt data and trigger a read failure. That, reckons Macrovision, renders SafeAudio discs unrippable. Every time you try to do so, you're told that the data has been damaged and the copy has been aborted.

The bypass, highlighted by European Web site CD Freaks, converts the disc tracks to .wav files in RAM and mounts them as readable volumes. At that point any .wav app can handle the rip. The bypass uses a custom VXD virtual device driver file. ®

*Macrovision claims that return rates on SafeAudio-encoded CDs are no higher than unprotected discs, but we're still not too happy about a technology that explicitly messes with a recording's fidelity. Doubly so, since it appears record companies don't seem too keen on actually telling consumers they're buying a SafeAudio CD.