Re: [ARSCLIST] CD-R question

[Jerry Hartke <jhartke@xxxxxxxxxxxx>]

CD-DA has two levels of error correction at the frame level. CD-ROM sectors
contain additional error correction, thus might be recoverable from more
significant damage.

CD-DA drives can compensate for uncorrectable errors by interpolation or
blanking, generating a few milliseconds of high distortion or silence.
Uncorrectable CD-ROM errors make the disc unreadable. Each have advantages
and disadvantages.

Jerry
Media Sciences, Inc.

> -----Original Message-----
> From: Association for Recorded Sound Discussion List
> [mailto:ARSCLIST@xxxxxxx] On Behalf Of Tom Fine
> Sent: Saturday, January 05, 2008 5:17 PM
> To: ARSCLIST@xxxxxxxxxxxxxxxx
> Subject: Re: [ARSCLIST] CD-R question
> 
> I had a go-around on a related topic, about whether CDR's full of MP3's
> get more damaged from
> over-time breakdown vs. audio CD's. My suggestion was that since data is
> packed tighter on an MP3 CD
> due to the lossy-compression format of the data, a relatively small glitch
> in the CD would zap more
> audio content. I was told this is not the case but was unconvinced by the
> argument -- which was
> basically that both audio and data CD's have robust error correction and a
> glitch of the same
> physical size would be correctable in both cases, or not. I still don't
> archive anything in a
> lossy-compressed format.
> 
> -- Tom Fine
> 
> ----- Original Message -----
> From: "Richard L. Hess" <arclists@xxxxxxxxxxxxxxx>
> To: <ARSCLIST@xxxxxxxxxxxxxxxx>
> Sent: Saturday, January 05, 2008 4:52 PM
> Subject: Re: [ARSCLIST] CD-R question
> 
> 
> > At 04:21 PM 2008-01-05, Howard Friedman wrote:
> >>And are you saying that a 534 minute CD will not survive as long as an
> 80 minute CD, all other
> >>things being equal?
> >
> > That is an interesting question. I would suspect that the likelihood of
> the 80-minute CD being
> > useable is higher than the 534 minute CD because in 50 years someone
> will try and play both in a
> > CD player and when one plays and the other one doesn't they may assume
> that the one that doesn't
> > play is no good and dispose of it.
> >
> > I realize that putting it into a PC drive and reading it would quickly
> educate the user, but I
> > fear the least-common denominator when it comes to technical savvy in at
> least some archives. Many
> > archivists try very hard to keep up with the technology, but archivist
> salaries are, sadly, rather
> > small in many places and their workload is heavy.
> >
> > When tapes started to squeal, many got dumpstered as "unplayable" with
> no recovery attempt made.
> >
> > So, I do think that it is not as safe to leave a non-mainstream CD
> around in an archive.
> >
> > As to the survival of the two from a photo-chemical perspective, I think
> that Jerry has provided
> > information about what that depends on. Disc type, storage conditions,
> and quality fo writer are
> > all key.
> >
> > The other thing to worry about with the compressed audio CD-ROM is that
> you will need to have the
> > proper codec to extract the compressed files. With WAV files, while you
> need a codec, it is the
> > simplest variety. MP3 will be decodable, I suspect, longer than many
> other formats.
> >
> > Cheers,
> >
> > Richard
> >
> > Richard L. Hess                   email: richard@xxxxxxxxxxxxxxx
> > Aurora, Ontario, Canada       (905) 713 6733     1-877-TAPE-FIX
> > Detailed contact information:
> http://www.richardhess.com/tape/contact.htm
> > Quality tape transfers -- even from hard-to-play tapes.