Found an article that mentions a method of preventing PC CDROM drives (and therefore PC CD copiers) from playing audio CDs by generating error information that an audio CD player will ignore, but will cause a PC CDROM drive to reject the CD as bad:

http://www.esware.net/empire/hardware/cdrom/news/9907/audiolok.htm

Of course (as I think someone else has said), unless you're a hardcore digitial audiophile, you can always rip an incoming analog stream from an audio CD player to get around any conceivable protection.

Gary

OOooohhhh - an insidiously clever bit of work. This hits at the heart of ripping, which doesn't sound good for our toy. I admire the ingenuity of this guy as it shows he is finally one of the first to latch on to just how primitive CD-A really is.

Now we have to wait with bated breath to see which companies start using it.

Damn!

I really hope they don't do this. All it will do is hinder people from doing what they are legally allowed to do, which is copy the media into a different format for themselves or for back-up reasons. Any hardcore pirate will just hook thier stereo to thier sound card's line in, dump the cd to thier hard drive as either mp3 or wave, then convert it to cd format and burn as many cds as they want to.
Let's all pray this does not happen. It will make our hobby a pain in the @ss.

Won't fly.

Reasons:

1) If they alter the formatting of the CD, there will be some audio CD players that will refuse to play the discs. I know a little bit about the way these things are formatted. Some players are more picky than others, and there will always be players that won't tolerate a disk with goofy formatting. No record company in their right mind would publish a CD that won't play on consumer equipment. Can you imagine how pissed the record stores would be if their customers kept returning the latest Ricky Martin album because they thought it was defective?

2) Different CD-ROM readers will read different discs. Even if they encode this onto the CDs, there will still be some CD-ROM drives that can read it. So the system wouldn't be 100 percent effective at copy protecting the discs.

3) Because of (2), albums that contain this protection would be distributed more vigorously on the internet than ones that don't. The users with the drives that have the capability of reading the CD will rip and post MP3s of the copy-protected albums. The effect would be the exact opposite of what the inventor intended.

As I've said before, the record companies opened Pandora's box over a decade ago when they embraced the CD format. It's an unencrypted, non-lossy system that allows perfect bit-for-bit duplication. Because CDs are such a universally accepted medium, there's very little they can do at this point, other than to adopt another distribution media format and make everyone switch. I don't see that happening any time soon because there are plenty of people still stinging from the fact that they had to buy all their LPs on CD over again.

Reminds me of the Tommy Lee Jones line in Men In Black. He shows Will Smith a super-tiny optical disk and tells him, "This will replace CD's someday. It means I'll have to buy the White Album again."

Some games companies don't seem to mind at all that their copy protection causes problems with some CDROM drives. Notably, SafeDisc and LaserLok both make the more intelligent CDROM drives (e.g Plextor scsi) say "Hey this disc is faulty, let's go at 1x speed". Took about an hour to install Championship Manager 3 because of this, and half the time movies in other games (e.g Descent 3, MechWarrior 3) don't run properly because the drive is running slow.

The stupid thing is that this still doesn't stop you copying the disc! It just takes about 4 hours while the firmware in your reader tries to make sense of all the bad data. And then you can make a duplicate with all the bad data in the right place...

The audio cd market is much more picky when it comes to compatability. CDs are supposed to just WORK. It's feasible that a hapless record company will start using this protection, only to find out that the consumer will be pissed off. And besides, as pointed out, I'm pretty sure some of the better CDROM/CDR drives will still be able to read them. I suppose they probably haven't asked themselves whether the inconvenience factor to pirates actually makes it worth the inconvenience factor to legitimate users. On the track record of games companies, they probably don't understand this.



- John.

(The above may not represent the views of empeg :)

I actually thoght about mentioning these topics when I posted that message, but got lazy. You're right: Copy protected games are a perfect example of how copy protection inconveniences the honest consumer.

An example: My CD-ROM drive won't read 80-minute CD's, a current favorite copy-protection technique. I've bought more than one game that can't be read on my CD-ROM drive. Recently, I bought Sierra's Homeworld, and it had this problem. The installation wouldn't complete because some of the install files were out past the 74-minute boundary on the disc.

Most folks would just return the game in this case. I didn't. I took it to work, got the files off the CD on a compatible drive there, downloaded a crack from the internet, zipped the cracked files, and took the zip home on my own CD-R.

It's ironic, because if the thing weren't copy-protected in the first place, I never would have needed to crack it and make a duplicate of the cracked copy. But now I have this cracked, zipped copy sitting here, ready to distribute illegally if I so choose.

Other games have given me similar fits: Thief, Freespace 2, etc. All honestly-purchased games that won't run on my existing hardware because of copy protection.

I work at a software development company, so I understand the need for copy protection. I don't begrudge the software makers for implementing it. All forms of copy protection are a trade-off: How much trouble do you want the legitimate users to have, compared to how much trouble you want to give the pirates. The final rule comes down to: If you can execute the code with the protection in place, then there will always be a way to execute the code without the protection. No matter how good your protection is, there will be pirates who can break it. The most effective copy protection schemes use some kind of remote server authentication mechanism: like CD keys that report back to the manufacturer over the internet. But even those can be broken if the pirates are willing to put enough energy into it.

But the most important thing is what you said: The audio CD market is much more picky when it comes to compatibility. Us PC users are willing to tolerate the copy protection because we're used to the fact that computers don't work perfectly all the time. Consumer audio has a much less tolerant set of standards. No one would put up with an audio CD that only played on some of the players. Even if "Some" was 90 percent, that remaining ten percent would be a nightmare for the record stores and record companies.

My (limited) understanding is that the AudioLok method uses the fact that there are three error "levels" that can be recorded on a CD. Two of these are ignored by audio CD players so if there's intentional error information in these two levels they will be ignored by audio CD players, but rejected by PC CDROM drives.

Since the majority of music is listened to on audio CD players and the majority of digital music piracy is done on PC CDROMs then I don't think the recording industry will be overly concerned.

I worked on a QC device in the late 80's at Philips when the CD-A standard was nicely established, and the up and coming thing was CD-ROM, in various format flavours.

I had to adapt a combined CD-V/LaserDisc player for use as a test instrument so that I could read out the error flag information being generated by the readback circuitry as it pulled the encoded symbols off the disc.

There were three classifications of error flag, E1 E2 and E3, and for each class, three levels. This means a range of 9 error criticalities, of which (generally) the Video playback circuitry used correction strategies at class 2, and the audio at class three.

Class E2.2 & 3 audio symbol errors usually resulted in a "mute" being applied at the audio output by the better players, or a "click" if no suppression was applied. Class E3.3 usually meant an irrecoverable tracking error, either in the motion servo tracking or in the focus servo tracking. This either meant the player would "jump" or it would "stick" as it tried to recover.

The strategy of muting, re-tries, or whatever was usually determined by the software engineering team who wrote the firmware for the player; this was usually controlled by the marketing team who (in one case where I actually have knowledge) decided that a player "sticking" rather than bailing out from playing the track and either moving on to the next track or stopping playing altogether was the best strategy - a user would be more likely annoyed by the player stopping playing, and would return the player to the shop. If it "stuck", then based on decades of experience with sticking LPs, they would blame the medium rather than the player and take the disc back to the shop, thereby handily switching the bias of the blame away from the player. Crafty bit of psychology, eh?

Anyway, the point of all this is that audio symbol errors on a CD-A are usually of very little consequence, since the player can to a limited extent compensate before giving up and muting (E3.3 errors are actually quite rare due to the quality control procedures used in manufacturing). However, tracking servo information is pretty critical, so this (to me) is where this protection method would work, by artificially introducing symbols into the servo control info at a level where the more rigidly enforced tracking standards required by any CD-ROM drive capable of running at above 2X speed would cause the drive to get upset.

Don't forget that a CD-ROM drive has no recovery strategy since it is not primarily intended for audio playback. Software CD players using CD-ROM drives have to look at reported errors and compensate accordingly; RIPpers like Audio Catalyst have to monitor tracking errors during data capture from the CD-A to prevent the introduction of errors in the audio stream. The only thing in common between a modern CD-ROM drive and a CD-A player is their common beginnings - like us and the apes.

I think this method will be used, without publicity, and the industry will go through an initial phase where they get massive returns of discs from customers who believe that they are defective. They will tolerate this, and with experience, they will eventually get the balance between playability and returns down to what they regard as an acceptable level against what they view as a revenue-robbing problem. They will also be doing this in the knowledge that the older CD-A players will gradually be discarded and replaced by newer players which will be prime candidates for technical mods to include latent protection methods that will be developed as the industry fights to put the lid back on the bottle. If they do decide to publicise it, it will be on the basis that the discs are being changed to include "more music" or "better sound quality" or some other almost unquantifiable, mushy consumer "benefit". People will (as is human nature) moan about it, then walk down to the nearest Comet or Dixons and buy the latest, newest, flashiest player they can get their hands on, and their old gear will be history.

I say this having followed the same b****** story with DAT recorders (available for nearly 4 years in the lab where I worked before they were released while management and marketing agonised over "protection" of the CD-A market) and the many abortive protection schemes and failed protected audio products that have appeared (and sunk) over the years. The CD-A market is too big for all concerned for it to lose profits by freely-exchangeable, legitimate music.

It's too late - but that won't stop 'em from trying....

Very good information, thanks. That was a very well-informed post.

Your conclusion is, of course, the other logical end result: The record companies could choose, via this method, to force the consumers to upgrade old hardware that won't play the new discs. This is risky for the record companies (as well as downright evil, IMHO).

But think about it... If an upgrade is required to read a CD, which consumer group is more willing to do the upgrade: The audio consumers or the computer consumers?

What I'm saying is... There will probably be some CD-ROM drives that will read the protected CDs, just like there will be some audio drives that won't. Those who are interested in ripping their CDs will just upgrade their CD-ROM drives to a model that'll do it for them.

This is more a general reply rather than specifically to Schofiel.

I've actually found the converse side of the 'ripping fidelity' debate to be interesting.

For instance - I recently compiled two CD-A's of my eighties songs to play on a trip (I don't have an empeg - my brother bought my queue number the bastard). I did this by choosing the MP3's that I had ripped, copying them onto ZIP, taking them to my brothers' place (he has the CD writer) and converting them to WAV with Winamp. The audio purists out there have already gone a ghastly shade of white at the mere thought of having all those possible errors around when I had the originals. They will go into a collective apoplexy when I reveal that some songs have small errors - blips, glitches, slight fuzzinesses where the read process didn't quite work. All these got put onto the CD-As.

I couldn't live with the tracks if they were from a low-bitrate MP3 and sounded like a computer reconstruction. But the little glitches remind me that I'm listening to a copy, and that I have the originals safe at home. They also remind me that these were taken from a very selection of eighties stuff and that there's a whole lot of other ways to compile it into CD-sized chunks. My current car stereo system isn't wonderful, so the actual reproduction probably masks any minor errors the MP3->WAV conversion process has introduced.

On a side note, I'd heard that people who complained of faulty CDs where the original CD they purchased had the error-rate copy-protection scheme (i.e. their CD player didn't like it) were given an exchange CD which had no copy protection. I.e. if you had problems copying it you could simply go back, claim you had a priceless hi-fidelity hand-crafted CD player that was more dear than your own mother to you and was far superior to everything else and it was clearly this disc that was faulty, not your system - and they would just give you a CD that was copiable.

Dunno for sure about that last bit, though.

Save the whales. Feed the hungry. Free the mallocs.

...some songs have small errors - blips, glitches, slight fuzzinesses where the read process didn't quite work.

Keep in mind that this thread was discussing a type of copy protection that hasn't actually hit the market yet. I read an announcement that certain record companies were planning on starting to implement it, but none of these CDs are on the shelves yet. (To save for another discussion: Won't it be funny when these record companies start getting returns on these CDs that won't play in everyone's players?)

Your description of the pops and glitches in the MP3s is not related to copy protection. When that copy protection comes out, there will be no way to "return the CD for an unprotected copy" to my knowledge. And the result wouldn't be pops and glitches, the result would be a completely unreadable disc.

So the pops and glitches you are experiencing are normal, and they are the result of either a) A CD-ROM drive which does a poor job of Digital Audio Extraction (DAE), or b) incorrectly configured ripping software. Digitally extracting the audio from an audio CD is a bit of a black art. Some drives have trouble doing it properly, and if your software isn't configured carefully to match your drive characteristics, you'll get the pops and glitches. Here is a discussion of the problems associated with digitally extracting audio from a CD.

If you're planning on getting an Empeg, you should take the time to make sure your rips are good. If your disc drive has trouble performing good rips, the WINDAC32 software is very good at sector synchronzation, and is the most reliable ripper I've seen. I used to use it all the time. However, on my system, I've found that AudioCatalyst does a faster job provided that I leave the system alone and don't do anything else on the system while it's ripping. If I don't leave the system alone, the rips will get pops and clicks in them.

Actually, I've found that a bad rip can have more subtle extraction errors, not as obvious as pops and clicks. For example, on my system, the most common problem is sudden reversals of the stereo image. For instance, an instrument suddenly jumping from the left channel to the right channel. If you're planning on ripping a lot of music, take the time to carefully preview the first couple dozen albums to make sure the ripping process is working perfectly. Do your previews with a good set of headphones at a fairly high volume, so you can detect subtle things like the stereo reversal problem I described. All of the songs I've ripped and loaded onto my Empeg are all perfect glitchless files. It can be done, and it's a good feeling to know that you can listen to your whole album collection without problems.


Tony Fabris
Empeg #144

I'm pretty sure the better rippers will be able to deal with this. cdparanoia has ripped incredibly scratched discs from my collection. Now, there may be certain cdrom drives that won't be able to deal with this, but most probably will, even if at a slower rip rate than normal.

Fly me to the moon...