Re: [gentoo-user] Verification of audio CD copy?

[Mark Knecht <markknecht@gmail.com>]

On Tue, Jun 2, 2009 at 7:42 PM, Paul Hartman
<paul.hartman+gentoo@gmail.com> wrote:
> On Tue, Jun 2, 2009 at 8:03 PM, Mark Knecht <markknecht@gmail.com> wrote:
>> Hi,
>>   I've got a bit of a problem recently with (I think) k3b. Over the
>> last couple of months *some* copies of CDs made in k3b using the Clone
>> Copy feature do not reliably play in my car's CD player. I've tried
>> multiple CD spindles and I've tried burning the copies on two
>> different Gentoo machines - one 32-bit and the other 64-bit - with the
>> same results. The thing that is VERY strange about this problem is
>> that some CDs and all copies of those CDs play fine. For other CDs the
>> originals play fine but every copy I make fails, and if they fail,
>> they fail using either Gentoo machine to copy them. (Hope that's
>> clear....)
>>
>>   I'm wondering if there is a program that can verify the contents of
>> each CD against each other, bit for bit, to identify whether this is a
>> problem on all of my computers or whether it's something about my
>> car's CD. The strange thing is that the original CDs play fine in the
>> car. It's only the copies that sometimes don't, and it's only the
>> copies of *some* CDs, not all CDs.
>>
>>   I've been using these same machine and same car CD player for years
>> and everything has always been fine. Now for the last 2-3 months
>> nearly 50% of what I copy fails.
>
> I don't think there's a way to do bit-for-bit compare of audio CDs...
> if it's a burning issue I would try burning at a slower speed (as slow
> as you can tolerate waiting for).
>
> Maybe your car's CD player/laser is dying. Perhaps try taking some old
> CDs that you know used to work and see if they still play okay. The CD
> player in my car for the past month or so has decided to be unable to
> play a CD without skipping like crazy. It is maddening.
>
>
Reading around on the web I got pretty much the same picture - that
it's not possible to verify 100% bit-for-bit that an audio CD is
identical. Still, I would think that if I made whatever the 'iso' is
of a single CD twice and compared the two of those I'd expect them to
be the same, but maybe we cannot really guarantee the burning
operation is exactly bit-for-bit. I don't know.

It likely is the car's CD player but it's been hard to prove so far.
It plays all originals fine. It plays most copies fine. However it
fails on all copies of certain CD lately no matter what Gentoo machine
I burn them on. Strangeness.

Thanks for answering back!

- Mark