Re: [ARSCLIST] Archiving CLV versus CAV transfer

[Eric Jacobs <ericj@xxxxxxxxxxxxxxxxxxx>]

Thanks for the sanity check.

In this case, the client wants to archive to optical media.  So
media cost becomes a factor.  An Audograph CAV transfer is about
22.5 minutes in raw format, and about 42 minutes when processed
into the CLV format.  At 24/88.2 you can just squeeze the CAV
transfer onto a CD-R.  But the CLV would need to be put onto
DVD+/-R or split across two CD-Rs, so the storage media
cost doubles if you have a large quantity to archive and you
want to archive to CD-R instead of DVD+/-R.

I agree that the CAV format has limited value, even with the all
the groove radii data.  So the processed CLV format seems like the
more useful/valuable content to archive.

Presuming that we archive the processed CLV format, the remaining
question is whether to split it across two CD-Rs, or store it on
a single DVD.  I tried various lossless compression algorithms,
but there's no way you can compress the CLV to fit on a CD-ROM.
Besides, compressing data is generally frowned upon for archiving.

Archival quality CD-Rs can be found (Mitsui, Taiyo Yuden).  But
the long-term life of DVDs remains unknown.  I hate to split the
files for CD-R storage, because this will make automation of
future digital migration clumsy.

Any further comments about CLV versus CAV archiving appreciated.

Eric Jacobs
The Audio Archive



---- Original message ----
>Date: Mon, 11 Apr 2005 17:28:06 -0700
>From: Mike Richter <mrichter@xxxxxxx>
>Subject: Re: [ARSCLIST] Archiving CLV versus CAV transfer
>To: ARSCLIST@xxxxxxxxxxxx
>
>At 04:20 PM 4/11/2005 -0700, Eric Jacobs wrote:
>
>>If cost and disk space were not an issue, one could store both the raw CAV
>>transfer, as well as the CAV-to-CLV converted transfer.  But if cost and
>>space are an issue, which transfer would you preserve?
>
>Please excuse my ignorance here - I've worked with similar situations but
>not in an archival context.
>
>The cost would appear to be essentially the same regardless of whether both
>are stored since the only additional operation required is to preserve the
>intermediate step. Space would be a problem if you intended to preserve the
>raw CAV in audio form, which as you indicate is essentially without value.
>Thus, the choice is whether to preserve a set of data - the radii and other
>characteristics as determined for processing and the raw WAV (or
>equivalent) file in some condensed form. Thus, my suggestion would be to
>preserve a text file on the parameters and a reasonable version of the raw
>CLV capture. That would be in addition to the CAV resulting from the
>processing, which would logically be in a form such as CD-DA or high-rate,
>two-channel WAV (or equivalent).
>
>If only one copy can be retained, clearly it would have to be the CAV. The
>CLV without supporting information would not even allow review for
>relevance; with the supporting data, it would still require costly processing.
>
>
>Mike
>--
>mrichter@xxxxxxx
>http://www.mrichter.com/