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Re: [AV Media Matters] The FILE is the thing ! Was -Digitizing Audio and Video
I love it when the Jims discuss things!
Jim (Wheeler) I agree with your point that archives cannot afford
things--but, from my experience, archives often can't afford the initial
migration from the original format.
Jim (Lindner), I agree with your points about migration being the only
way
to ensure that files remain readable. In your point (4), below, you
discuss
the application to read the file as one of the challenges. I see that
point
involving any media that you lock away for extended periods of time:
disk,
tape, disc, flash ram, whatever. However, the challenge of morphing
files
from one form to another is far more daunting than the challenge of
migrating files from one medium to another.
Let's (for the sake of this discussion) agree that "morphing" the file
means changing it in a trivial or non-trivial way so a later application
may read it. In this process, you may break the ability of the
application
that generated it to read it. Let's take, for example, a Microsoft Word
document that was created in version 6.0, the Windows 3.1 version. When
you
open that document in Word 2002, and save it, Version 6.0 can no longer
read it, unless you use the "save as old version" command from Word
2002.
When you "save as old version" you lose features that you embedded in
Word
2002.
Note, however, that this morphing is done by the application which, over
at
least a short period of time can at least demonstrate read compatibility
(to some degree) with older versions of the file.
Another example from word processing. I have some files that are in Word
Perfect 4.2, I believe. Microsoft Word 97 and 2002 do not recognize
these
files. If I open them in Word Perfect for DOS version 5.0 and then save
them WP 5.0 has created files that MS Word 97 and 2002 CAN read and then
save in their native formats. This is an example of a two-step MORPHING
process, and one of the things that Jim (L) rightfully is afraid of with
media files.
In general, the concept of data MIGRATION, is copying the same file from
medium one to medium two assuring that it is not corrupted in any way. I
am
not sure how much MORPHING of the file happens during this MIGRATION
process, as the MIGRATION generally happens at the operating
system/storage
file system level rather than at the application level.
Let's look at another simple example from the word processing world--the
reason for this will become clear in a moment. If I have a document in
Word, I can fully edit it and all of the component parts are accessible
for
modification. If I publish this as an Adobe Acrobat (PDF) document, I no
longer have the document in as editable a form as when I had it in Word.
That is the beauty of the system, that is the pitfall of the system. I
suspect that Adobe (and if they're no longer around, someone else) will
maintain long-term readability of PDF files on a variety of operating
systems (including the Palm, by the way). However the PDF is not the
same
as the Word document for repurposing (editing) for future use. I can
capture pieces of the PDF, but, for example, the graphics are
down-rez'd
and the entire document is often (and should be) password protected for
extracting pieces.
This is where MXF and AAF come in. These are universal formats. In some
respects, one can think of AAF as the Word document with all of the
instructions and all of the pieces for assembling the final video. The
final video, in a flattened form, can be distributed as an MXF file--and
that is, at least on a simple level, the moving image equivalent of the
Adobe Acrobat file.
AAF is certainly an emerging standard and it, in itself, is changing
over time.
So, I think we all agree that the file is the thing (thanks Jim (?) for
a
good subject line), but I'm not sure that we agree or understand how
that
file will be treated.
If we assume that the file has to be MORPHED as it is MIGRATED that is a
new responsibility to put on the IT professionals as I understand their
job
description. There are artistic judgments in assessing how to MORPH a
file--at least to the extent of "what options do you still want to do on
the file." Perhaps the options can remain completely open, but
rich-content, editable files such as AAF pose huge challenges for
maintaining compatibility over time.
One of these challenges is that the transforms applied to media are to
some
extent proprietary and the transform in software application "A" may
sound
different from an equivalent function in software application "B." When
we
add in the option of dedicated hardware processing (yes, that is still
done, especially in video, just ask the folks like Quantel) then the
gamut
of processing possibilities broadens. One of the features of AAF is the
ability of proprietary processes to encode "dark metadata" known only to
that proprietary process. You will need that proprietary process to
render
the file.
Bottom line, we're best off -- in my opinion -- of storing individual
elements as well as rendered copies in the way the producer wanted to
see
them. In essence the final PDF plus the individual text and graphic
elements that went into the PDF. This is not so we can create the final
PDF
again--we already have that--but so we can repurpose pieces of that to
satisfy different demands of different revenue streams by using the same
underlying data in differing combinations to tell different stories.
If we accept that limitation, then the MORPHING process becomes less
challenging and might be able to be done as part of the MIGRATION
process,
but I still see the MORPHING as a separate step. I also see PDFs, JPGs,
and
MXFs as long-term readable formats that will be supported at least for
input well into the future, unlike Word Perfect 4.2 for DOS.
But now, back to Jim W.'s initial question, what do we do for archives
who
don't have the budget and their material is wasting away? We had a long
discussion on AMIA-L and a bit on ARSCLIST about an audio archive that
we
suspect is wasting away due to too-high humidity in their storage
environment.
We took a poll and received mixed responses--no consensus--but the
responses were predictable based on the prejudices and experiences of
the
respondents. The bottom line, however, is that it's probably less
costly--at least for the near term--to fix the environmental problems
than
it is to transfer the complete collection--and then maybe do it again in
20-40 years. There is no funding for a file-based, IT-based central
archive
for this material. There should be, but there isn't.
I[ve deleted the posts by the two Jims--if you want me to forward them
to
you, please let me know.
Cheers,
Richard
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