Re: arsclist Digital knowledge preservation

["Richard L. Hess" <arclists@xxxxxxxxxxxxxxx>]

We are having this precise discussion in the AMIA (Association of Moving 
Image Archivists) mailing list where it is heretical to suggest any form of 
lossy compression. On the other hand, we've had many analog systems that 
provide lossy storage to the original signal.

We have also had the discussion here that the CD Audio Red Book standard 
isn't good enough for archival purposes and we need higher resolution, 
although many of us are happily transferring sound to uncompressed, 44.1/16 
CDs.

One thing to consider in selecting a format to store to is that it is truly 
as lossless as possible for the vast majority of material contained in the 
archive. On the other hand, the format has to be well-supported with the 
anticipation that players will be available long into the future.

In the video world, for example, if you have a holding on VHS tape it 
doesn't make sense to bump it up to 270Mb/s for storage in the digital 
domain. On the other hand, converting it to a 2Mb/s MPEG file and putting 
on a DVD isn't the right option, either, as the preservation format. 
Something considered essentially lossless, like 50Mb/s MPEG or DV is 
considered (at least by some) to be a good compromise.

I do not know the bitrates that are being coded to for the MP3 audio files 
mentioned in this post, but the difference between 192Mb/s MP3s and mono 
WAV files at 44.1/16 is about 1:3.7. I'm wondering if the savings of $7.00 
and seven discs is worth the additional compression. These figures relate 
to making Red-Book audio CDs. The difference would be $3.00 and three discs 
if there were mono WAV files on the CDROM.

One important item to consider for audio transfers is that the cost of the 
final media is only a very small percentage of the final transfer cost. The 
biggest single cost is the staff to do the transfer as that staff needs to 
be skilled in making the transfer and in all of the arcane optimizations 
that must be done to (and the mechanical pre-processing that must be done 
before) the analog reproduction chain.

The good news,  however, is that a large collection of items are being made 
accessible and being preserved in at least one form for future generations. 
I believe that our grandchildren will be happier if more is saved, albeit 
at SLIGHTLY lower quality than if only the pinnacle of quality is saved and 
many things were lost.

Cheers,

Richard

At 09:11 AM 6/18/2002 +0000, you wrote:
> On 17-Jun-02, Mike Richter wrote:
>
> > Having suffered the problems of recovering aged data, I recommend that
> > ARSC establish a set of digital formats for its records in order to
> > minimize the risk of obsolescence. I limit my own attempts at
> > preservation to self-contained CD-ROMs in strict ISO 9660 format and
> > include Windows retrieval capability. The language is HTML 2. Audio
> > files are in MP3, which is not as well-defined as I would prefer.
> > Unfortunately, the alternatives (WAV, AIFF) are inefficient in use of
> > space and would not serve my purposes as well.
>
> It seems unwise to me to use lossy compression for any form of archival
> storage. Once that information is thrown out, you can't get it back.
>
> Regards
> --
> Don Cox
> doncox@xxxxxxxxxxxxxx
>
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