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Excessive Copy Protection?, Mp3 related
Dub45
post Jan 3 2003, 05:31
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This may be old news to some of you but its the first time that I have come across it.

I have just bought a copy of 'Round about Roma' by Stefano Di Battista on Blue Note.
This disc does not seem to have been released in the US yet.

I put it into my pc to have a listen while I browsed and suddenly a player that I had never seen before appeared! Anyways the cd provides its own player but apparently will not allow me to use my usual player to rip it as I usually do for use on my ipod.

When I opened the cd through explorer it does not display the audio tracks separately.

This is infuriating (I dont share MP3s on the net and I don't download them) but I can't listen to an album that I have bought as I would wish!

I presume the introduction of the player is to get over the complaints of cds not being playable on pcs.

Any other incidents of such cds? What are other people's views?

Incidentally I tried to copy it on a 'normal hi-fi type copier and it wont copy either!
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Pio2001
post Jan 4 2003, 22:47
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QUOTE (tigre @ Jan 4 2003 - 03:28 PM)
The first position with different samples is an exception (weird). The Plextor drive ripped about 3000 samples of digital silence (clearly audible wrong) in the middle of one song while all other drives' results are identical and sound fine at this position. IMO this is a strange behavior of the Plextor drive. C2 was deactivated, test & copy CRC are identical, I even tried with different firmware versions (with/without caching)!? :blink: Any explanation?


Maybe it has something to do with the sync markers of the CD. In http://www.digital-inn.de/showthread.php?t...=4833#post14345 , Andre Wiethoff wrote :
QUOTE
But Cactus Data Shield 200 is ugly...
illegal TOC, wrong syncmarkers, mastered C2 errors, multisession...

The syncmarkers are used by computer drive in order to access a given audio sector, while hifi players follow continuously the groove. Maybe the Plextor is disturbed by a missing syncmarker.

QUOTE (tigre @ Jan 4 2003 - 03:28 PM)
I've got 4 wav files of every track and no matter which two of them I compare, the different samples are exactly the same (,but with different values for every drive, of course).


Are these errors audible ?

This is a complicated matter. Any error should always return the same value, because it is concealed. EAC error correction (reading twice) and CRC mismatching must be triggered by some errors, even very few, that doesn't occur all the time. EAC compares blocks of 27 sectors, that is 15,876 samples, in order to search for errors in secure mode without C2. If only one error among these samples occurs reading once and doesn't the next time, the error correction bar lights up.

But different drives use different error detection algorithms. The mastered errors used by Datashield 200 should therefore be bad enough to defeat the most powerful chipsets. But then, the amount of wrong samples returned won't be the same on drives using different error correction strategies.

Therefore when you compare tracks ripped by different drives, the differences you see are the errors corrected by one drive and not by the other, and not all the errors on the CD. They should be always at the same place, but also have always the same value. Comparing with a third drive, you might get differences at the same place, and possibly with different values (if the error correction strategy is the same, but not the error concealment one).

But comparing two extractions from the same drive, it should be easy to see differences in the positions of the errors, because an error can only have two values : the right one (error corrected), or the interpolated one (error not corrected, thus concealed). Ripping thrice (A-B-C), all differences you can see between two given wavs (A-B) should therefore not be visible in at least one of the two other possible comparisons (A-C or B-C). This, assuming that the drive does conceal errors.

If you are insterested, you can try to detect the error correction and error concealment abilities of your drives following my method : http://pageperso.aol.fr/lyonpio2001/dae/dae.htm
It's not finished yet, but it can be useful here.
The way to detect the error correction strategy is explained in appendix 2. You don't need to understand all the calculus. All you need is understanding how to run Andre Wiethoff's DAEquality package, and download the calculated patterns at the end of part 3.3 of the appendix 2 of my page.
If a drive uses EFM info in order to flag errors, you will see bits of these patterns, with every other group of 2 or 3 wrong samples shifted 6 samples to the left.

There is no reason for these patterns to match yours, because Cactus datashield must not have used burst errors. But this way you can see if you must expect different behaviour between your drives, and if so, between which ones.

By the way it is strange that the errors show a regular pattern. Key2audio stated that the place of the errors was carefully chosen so as not to have an audible effect. Maybe it is not the case with Cactus Datashield.

QUOTE (tigre @ Jan 4 2003 - 03:28 PM)
How could I get rips with least/lowest possible errors without having to spend hours of handwork correcting sample values?


Use the SPDIF output of a hifi CD Player. Note that you need a soundcard capable of recording without resampling in order to get no errors.

It should be possible to correct the files on the computer if the error positions are always the same with Matlab. Mac successfully did it : http://www.hydrogenaudio.org/forums/index....t=ST&f=1&t=4206
The problem is to know all the exact positions. So far, you've only got the differences between the positions detected by one drive and the positions detected by another.

QUOTE (tigre @ Jan 4 2003 - 03:28 PM)
The way I understand forum rule # 9 I'm not


Quite strange indeed. I never noticed that this rule specified
QUOTE
9. Links to copyrighted or illegal material, discussion containing information of how to obtain such material, bypass protection methodologies of such material, or otherwise violate laws pertaining to such matters, will not be tolerated.

Fair use of short music clips (under 30 seconds) for codec testing purposes are allowed.

Users found in violation of this rule will be subject to immediate banishment.


Emphasis is mine.
If this rule would have been respected, I should have been banished as soon as I posted the FAQ thread, because of the link to CD Freaks about how to backup protected CDs.

Administrators, what are we going to do ? Modify rule 9, or remove the links ? On one hand, software capable of bypassing protections are illegal, on the other hand, one third of computer drives on the consumer market are natively capable of bypassing protected CDs... The problem is the status of audio CD protections... they actually do not prevent copying (analogly).

This post has been edited by Pio2001: Jan 4 2003, 22:52
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Posts in this topic
- Dub45   Excessive Copy Protection?   Jan 3 2003, 05:31
- - Sachankara   Return the disc and demand your money back... Arti...   Jan 3 2003, 05:33
- - woody_woodward   I agree. The disk is defective. Take it back. T...   Jan 3 2003, 06:59
- - CiTay   QUOTE (Dub45 @ Jan 3 2003 - 05:31 AM)I presum...   Jan 3 2003, 14:44
- - theduke   QUOTE (CiTay @ Jan 3 2003 - 02:44 PM)The play...   Jan 3 2003, 14:48
- - ronnie_t   see this topic on cdfreaks. It tells you how to re...   Jan 3 2003, 23:10
- - Gecko   I've also had one of those (Dj Convention - Co...   Jan 4 2003, 00:05
- - kennedyb4   QUOTE (woody_woodward @ Jan 3 2003 - 12:59 AM...   Jan 4 2003, 00:55
- - tigre   I got a similar cd as christmas present. It launch...   Jan 4 2003, 03:41
- - Pio2001   QUOTE (tigre @ Jan 4 2003 - 05:41 AM)there ar...   Jan 4 2003, 04:45
- - tigre   @Pio2001: Before I forget about it: You're a ...   Jan 4 2003, 13:28
- - layer3maniac   QUOTE (tigre @ Jan 4 2003 - 04:28 AM)could yo...   Jan 4 2003, 13:57
- - SK1   Maybe it's got something to do with a hacked f...   Jan 4 2003, 14:47
- - tigre   OK I trust layer3maniacs statement. What I did is ...   Jan 4 2003, 16:58
- - Pio2001   QUOTE (tigre @ Jan 4 2003 - 03:28 PM)The firs...   Jan 4 2003, 22:47
- - outscape   >>>'Anyways the cd provides its own ...   Jan 5 2003, 07:58
- - ronnie_t   I succesfully made a backup of my cactus-protectec...   Jan 5 2003, 13:10
- - deej_1977   Hi all, In this thread I complained about copy pr...   Jan 5 2003, 14:29
- - tigre   @Pio2001: Thanks a lot for your detailed informat...   Jan 8 2003, 19:42
- - neomoe   Tigre, do you know a non-commercial program with ...   Mar 18 2004, 06:23
- - tigre   I don't know any software capable of doing thi...   Mar 18 2004, 07:46
- - shadowking   Sounds like Cactus data shield CDS200 protection. ...   Mar 18 2004, 08:56
- - Lev   QUOTE (Gecko @ Jan 4 2003, 12:05 AM)What both...   Mar 18 2004, 09:58
- - jido   QUOTE (tigre @ Jan 3 2003, 06:41 PM)I got a s...   Mar 18 2004, 10:59
- - tigre   Just in case noone noticed so far: This thread is...   Mar 18 2004, 13:54


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