[Paranoia] unable to rip some audio cds that play without error

[Paolo Saggese]

On 2015-08-28 19:09, richardm wrote:

> I have a few audio CDs that refuse to be ripped by cdparanoia.
[...]
> However if I play the cd on an audio system I never seem to get
> a problem - not one that I notice.
[...]
> The CDs in question are not SACDs - they seem to be regular audio CDs
> produced by Warner Music France. I've also returned then to Amazon for
> replacements but the same behavious. The can't be read by cdparanoia or
> any other audio cd software eg vlc.
>
> Any one have any insight into that is happening. Are these discs faulty?

as someone else already suggested, most likely those CDs have been 
crippled with some kind of "copy-protection". :-(

Those crappy stuff usually works by deliberately deviating from CDDA 
(Red Book) standards and/or adding errors, illegal Table Of Content 
entries, multi-session tricks, etc.

(Hint: check the CDs and their envelopes for any "anti-piracy" marking 
and logos, as well as for the presence of the official CDDA logo which 
in principle is not allowed to be present on crippled CDs).

Read more here:

  http://en.wikipedia.org/wiki/Copy_protection#Audio_CDs

as well as here:

  http://www.co-bw.com/DMS_how_to_rip_copy_protected_cds.htm

etc.

These things are very hardware (drive) dependent: using some CD/DVD 
drive you may be simply screwed (no way to rip or even just play the 
"protected" CD) while other ones may work without troubles.

It may also depend on the combination of the specific "protection" 
scheme(s) adopted by a given CD and the drive used to (try to) read it: 
some particular drive may be able to read a subset of the crippled CDs 
while another one may be able to deal with a different subset.

Thus, what I can suggest you is to try to rip any troublesome CD using 
different drives (of different models, brand, type, age...).

Some (though possibly not all) of those crap may be circumvented by 
adopting specific tricks and counter-measures at the ripping software 
level. In fact, a specific old version of "EAC" is known to be able to 
defeat at least some of those "protection" schemes.

Probably it used some "non-standard" way to rip the non-standard (e.g. 
multi-session) CDs, tried to detect and fix illegal/bad TOCs, etc.

The feature have been removed from later versions and that specific 
"tricky" version is no longer officially distributed. Though it can 
still be found in some "underground" sites on the net.

It would be really nice to have some similar trick(s) implemented in 
cdparanoia too. ;-)

Perhaps some more tricks could/should be implemented at kernel level 
(cd-rom / atapi / scsi interfaces, etc), but having cdparanoia trying 
hard to do anything it can do at its own level would be really nice anyway.



Ciao,
                                 Paolo.

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