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Macrovision CDS-300 version 7 beta

A CD lock-in tech that only annoys P2P traders?

By Tony Smith, 25 Aug 2004

Exclusive Macrovision describes version 7 of its CDS-300 copy protection system as a major step forward in keeping P2P users' hands off copyright content for which they don't have the distribution rights. Having seen a demo of the alpha release, which performed as advertised, we were nonetheless pleased when a copy of the latest beta version turned up in The Register's mailbag.

Since the alpha release, Macrovision has shifted the system's focus away from tinkering with the contents of the CD Audio session - a technique it calls 'passive protection' - and toward smarter use of multiple disc partitions, or 'session protection'.

That should help appease hi-fi purists concerned that the addition of deliberate errors into the audio datastream reduces the effective lifespan of the disc. CD playback requires a hefty level of error correction to yield the sound clarity for which the medium is famous. Adding noise to the audio content may fool ripping software but, say some observers, it also further taxes CD players' error correction systems, which may already be having to cope with scratches and grease on the disc's surface.

Beyond a certain point, the theory goes, the error correction mechanism will not be able to cope, so by adding errors to the datastream, Macrovision is reducing the amount of damage a disc can take before it becomes unplayable. We'd say disc buyers should take better care of their CDs, but Macrovision has nonetheless scaled this element of its copy protection scheme right back.

Indeed, we were able to duplicate the CD Audio part of the disc - the Red Book session - and there was none of the irritations such deliberate errors are supposed to induce in computer-made copies.

Session player

But back to session protection. Essentially, this is the old technique of hiding multiple disc sessions from systems for which those sessions are irrelevant. When CDs might once have incorporated data as a 'track 0', which would have shown up on a CD player but played as either white noise or silence depending on the sophistication of the hardware, multi-session mastering allows, say, the Mac OS partition to be hidden from Windows users and vice versa - and for both to be ignored by a CD player. Multiple sessions are now part of the CD spec, courtesy of the so-called Blue Book, which covers Enhanced CDs and was developed by Philips, Sony, Microsoft and Apple.

CDS 300 Version 7 UI

On the office Windows XP box, the CD Audio session is thus hidden from inspection - only the PC-compatible session appears in the My Computer folder. Holding down the Shift key prevents the session from auto-running, but double-clicking amounts to the same thing: Macrovision's own Flash-based applet is launched and instances Windows Media Player (WMP) for playback. Session protection ensures you can't access the CD Audio even if you do hold the Shift key down, at least not through Windows itself.

Exploring the disc session reveals the 192Kbps WMA files offered to PC users as an alternative to the Red Book tracks, along with the various DLLs and CD burning code - of which more later.

Licensed to ill

Whether you run the disc automatically or double-click, you're presented with a software-style licence-acceptance screen. Click install and the software sticks an appropriate Windows Media DRM licence on your machine. It also installs - as you'll see if you read the Ts&Cs blurb all the way through - a "small program" to protect copyright material. This is the second strand to Macrovision's anti-duplication bow, what it calls 'active protection'.

CDS 300 Version 7 UI

Macrovision is adamant that the app isn't spyware - it "does not and cannot collect, retain, or transmit any information whatsoever about your computer or people who use it", the company states emphatically - but it does act to interfere with ripping software, and it's on that basis that the company claims 99 per cent effectiveness against attempts to rip the disc.

Morally reprehensible? Not entirely. You can easily elect not to install the software, but then you won't get to hear the music on your PC. Copying the files to your hard drive and attempting to play them prompts WMP to dial up a licence acquisition page.

Choosing not to install the licence and anti-rip code simply results in the disc being ejected. Agreeing to the installation will allow you to play the songs in either the Macrovision UI or through WMP itself. You'll also be allowed to copy the DRM'd songs to your hard drive and - label permitting - burn them to CD.

Like CloneCD and other apps of its ilk, Macrovision's home-brewed CD burning code - which again must be installed before proceeding - requires a CD-R drive that supports 'raw' mode. It needs this in order to enable it to implement session protection on the duplicate, the idea being that you'll be able to play the disc in your car or on your hi-fi, but not in someone else's PC. The burned copy lacks the content of the copy-protected disc's Yellow Book data session(s), but those sessions are still present in order to hide the Red Book content.

Having accepted the licence you can listen to the songs in WMP, RealOne or any other Windows Media DRM-compatible app. We tried iTunes' WMA-to-AAC conversion, but it proved sufficiently DRM-savvy to reject the file.

iTunes can't see the session-protected CD Audio files any better than WMP or RealPlayer can. Or rather, iTunes for Windows can't. The music jukebox's Mac OS X version, on the other hand, like the Mac operating system itself, has no problem accessing the CD Audio session alongside the appropriate Yellow Book session, and producing some very nice quality AAC rips.

CDS-300 version 7 incorporates a Mac OS player - for both 9 and X - but since the OS mounts both the CD Audio and Mac sessions as separate volumes on the desktop, so what? Taking a look within the Mac data session reveals the player and a /Player directory within which is a file containing the data you need for your ripped songs' ID3 tags. There's also a hefty 32.9MB .cds file that contains the encoded audio data the player uses.

That Mac OS X exposes the CD Audio session also makes it possible - as we did - to use Roxio's Toast to copy said session onto a CD-R which could then be played and ripped on the Windows XP machine. Or uploaded to a P2P network.

CDS 300 Version 7 'hidden' audio... in iTunes

Running Macrovision's own Mac OS player provides basic playback facilities, but without the burning option offered on Windows - or the licence and anti-rip driver installation. This may come in a future version of CDS-300 - it's certainly on Macrovision's feature roadmap.


CDS-300 version 7 is scheduled to be released next month. It's still in beta, so Macrovision may well have the Mac OS X issue sorted out by then, if it can figure out how to hide the CD Audio session from the OS.

If it doesn't, it may well get Apple's co-operation to tweak the OS in a future update. Macrovision is confident that it will support Apple's FairPlay DRM scheme in a Q4 software update, suggesting that it has reached, or is about to reach, an accord with the Mac maker. If it licenses FairPlay it may well persuade Apple to neuter OS X's CD Audio mounting.

That leaves Linux. Alas we don't currently have a machine running the open source OS machine in the office, but we suspect it probably treats multiple disc sessions as multiple volumes as OS X does.

Speaking of audio duplication, we tried the copy-protected CD Macrovision sent in a number of different players, from home hi-fis and DVD players to the office ghetto blaster and it played without hitch. Our tests of necessity could not be extensive, but Macrovision claims its own trials show a high level of device compatibility. But it will still suck if your particular machine is one of the ones that don't like session protection.

In adopting session protection rather than the older, 'passive protection' mode, Macrovision is trading more rigid protection for better compatibility. The company accepts that illicit duplication is never going to go away, and its copy protection scheme is essentially about attempting to minimise piracy rather than eradicate it. CDS-300 version 7 will certainly not stop analog duplication from the CD Audio. Nor, so far as we can tell, will it stop folk sharing the original disc and simply installing the licence on multiple PCs.

Macrovision presumably feels that sufficiently few folk will do so, or can be bothered to jump through hoops to rip the songs just for the sake of posting them on a P2P network. Instead, it believes, they'll settle for the easier approach, particularly since it allows them to do pretty much everything else they'd do with an un-protected disc.

Hence the burning code, and its upcoming RealTime DRM Encoding technology, which will create FairPlay-protected AACs, ATRAC 3 or WMA files from the Red Book source depending on whether you're running iTunes, Sony's SonicStage or WMP, on your PC or Mac. Punters get the format they prefer and (potentially) the right to make back-up copies - just not scope to post the files on Kazaa or one of its ilk.

The end of CDs as we know them?

No one who's got music without paying for it has any real cause to complain about all this. But it does represent an infringement of the freedoms those who haven't used a P2P network have come to enjoy. Ripping a CD you've bought so you can transfer it to your iPod remains illegal in the UK and other parts of the world, even if you haven't the slightest intention of giving the songs to anyone else.

What worries us is that the labels will choose to enforce the letter of law through such technology, rather than simply using it to prevent activities that are harmful to them. Stopping someone copying their own CD for use in the car or on an MP3 player is not the job of the labels, but they may very easily decide that it is. Certainly history suggests it will try to stamp on such uses, no matter how irrelevant they are in comparison with serious, mass-duplication piracy of the kind that takes place in the Far East.

Macrovision may seem complicit in that, but at least it can't be faulted for attempting to support personal uses: 'rip' to a portable player, make back-ups, make a copies for the car, etc. CDS-300 version 7 is the closest the copy protection business has come to providing discs that are compatible with personal 'fair use' provisions, where such provisions exist.

There's work to do - broader support for non-Microsoft audio formats and DRM schemes, for a start - but it's coming. A question mark remains over how far Macrovision's customers - the music industry pigopolists - will go to allow consumers to make use of functionality the company has built in. Macrovision can portray itself as the music consumer's friend, but that will count for nothing if Warner, EMI, Sony-BMG, Universal and co. - or, it has to be said, the artists and publishers - say they don't want to permit CD burning.

Then there's the issue of Macrovision's 'active protection'. Like the multi-session structure of the copy-protected disc, this has been tested for compatibility as thoroughly as possible, but Macrovision can't guarantee that its 'anti-rip' software will not interfere with every single driver on a user's system. But as with support for alternative codecs and DRM schemes, so better hardware compatibility should come over time. ®

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