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Re: locating an analog audio cable

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On Thursday, February 16th, 2012, at 10:38:22h -0500, Haines Brown wrote:

> J.G., I apologize for the long delayed reponse to your helpful note, but
> a question remains.

No problem -- I do understand you are very busy with your project.

> I understand that some CD manufacturers defeat the standard DAE
> method from a CD disk by adding some anti-piracy tracks to
> it.

Yes -- from what I recall it is simply that they add a track containing
just data marked as non-audio, possibly just junk, between audio tracks and this
confuses the process under Windoze at any rate into not knowing if it is
an audio CD or a data CD and thus renders it unable to "rip" (DAE).

I do not know if there are any applications under Windoze which circumvent
this problem, but if there are, they may be illegal in the USofA because
of the DMCA.

And under GNU/Linux I have to confess I do not know if there is the same
problem with DAE used by CD players such as the CD player for KDE,
except to suggest that you try and see what happens, but do not be at
all surprised if it does not work.

> Is there any way to know if such tracks exist other than being unable to
> play the CD disk? Is this mechanism now fairly standard, or is it
> unusual?

To be honest I do not know.  It is possible for example to have a CD
with audio on and I think if I recall correctly a valid data partition
which you can mount (ISO9660) which does not affect playing of the
CD by DEA.  There was a time when some CDs were distributed with
extras such as images or even an application for windows.  In fact
some game CDs were hybrids -- they contained the game application
on one part of the disk, and regular CD tracks as music to play
with the game or just to listen.

So the extra junk data to prevent DAE is not a proper data partition
on the disk.

Thus the only way to check I think would be to install the pseudo
cdfs kernel module and to look at the possibility of mounting the
cd tracks as a filesystem and see if there is extra junk.

I also recall a big long discussion years ago in which it was made
clear that the actual audio tracks are not themselves files on a
filesystem, although with cdfs you can see them as pseudo files.

> Do I understand correctly that if DEA is defeated, then one must use a
> suitable wire connection between the CD drive and the sound card?

Yes, and if possible use the SPDIF digital audio (2 wire) cable
to digital out on the CD and digital in on the sound card rather
than the older analog (3 wire, four pin connector) setup.

> That is, does the wire connection get around the anti-piracy block of DEA?

It is not that it gets around it, it is because DAE is never used
and the CD is just being played as a regular audio CD.

Remember that with DEA, what is actually happening is that audio
tracks are being "ripped" from the CD and then played, and of
course this is being prevented in an attempt to prevent the
saving and copying which is possible after ripping.

DAE allows you to very quickly grab the audio contents of the CD,
whereas with the play the CD via SPDIF, although copying can still
be done through the sound card, it takes as long as it takes
for the CD contents to play.

Hope this is an acceptable and adequate, but not fully detailed, explanation.

For more details take a look at

<http://dbpoweramp.com/spoons-audio-guide-cd-ripping.htm>

particularly the section "Copy Protections Employed"

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Thread

locating an analog audio cable Haines Brown <haines@HistoricalMaterialism.info> - 2011-12-06 13:24 -0500
  Re: locating an analog audio cable Clemens Ladisch <clemens@ladisch.de> - 2011-12-06 21:46 +0100
  Re: locating an analog audio cable J G Miller <miller@yoyo.ORG> - 2011-12-06 20:56 +0000
    Re: locating an analog audio cable Haines Brown <haines@HistoricalMaterialism.info> - 2012-02-16 10:38 -0500
      Re: locating an analog audio cable J G Miller <miller@yoyo.ORG> - 2012-02-16 17:31 +0000

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