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RE: [AV Media Matters] Digest for AV-Media-Matters@topica.com, issue 310

<Bob Savage said:
>> Unfortunately I would have to say that no "standards" exist
>> for archival reformatting of video; the biggest sticking point being the
>> lack of a wide-spread format that does not use compression. Your
>(unappealing) choices are to let the stock deteriorate without doing
>> anything, or pick a format that uses compression.

<Tony Gardner commented:
>In archiving, preserving, it is the lifetime of the support - the
>of the bits of the analogue signal - which must be the prime concern.

<Bob Savage responded:
<These are actually two different things. "lifetime of the support" I
<addressed in my "deteriorate without doing anything" remark, "integrity of
<the bits of the analogue signal" I addressed with my reference to
<compression; the OED defines 'integrity' as "The condition of having no
<or element taken away or wanting." Compression schemes function by throwing
<information away; to call the result something which preserves the
<of the source signal is to misspeak.

It really depends where you begin:
In choosing a support and recording system then one is looking for a system
which permits you to get back exactly what one puts in, bit for bit, and -
in the context of preservation, to  be able to do this after X years where X
is big.
This is independent and nothing to do with compression of video. What goes
in must come out, independent of what it is that is actually going in.
It has to do with the quality of the support/recording
layer/binders/machines and the rest of the alchemy. This is wholly
consistent with the OED definition.
This for me is the very heart and essence of preservation.

In the fabled ideal world, I would then put onto this 'uncompressed' video
(whatever that is??).

In the real world I have choices. If I chose (wrongly) to archive my D1
tapes as 28.8Kbps realtime streaming files, then I would expect at any time
to get the same file bit for bit from the tape. That's what I meant by

If of course you look at the chain from original (digital) video to
reproduction of it, then non-lossless compression is by definition throwing
out or modifying picture content and integrity is not maintained.

My proposition remains that compression is certainly ONE of the important
issues in broadcast TV preservation, but only in so much as it needs to be
carefully chosen as part of the whole compromise which permits one to do
something very valid and useful now rather that waiting for an undefined
better tomorrow. I don't see compression as unappealing - anymore than
storing valuable information on magnets glued to a base wound up in a
plastic box in another plastic box is 'unappealing'. They are both just part
of the equations. Its life. Its also the standardisation that's going on now
in the broadcast world for archiving by the broadcasters.

<Tony Gardner said
>Here and now we are, often in a position to have to make a decision. Doing
>nothing can be a cop out. So, life is compromises, the stuff of
>Make rational well informed compromises. Get the right questions in the
>right order. Don't get hung up on single issues, which don't stand up to
>informed holistic debate. Don't (only) dream of a better tomorrow, take
>responsible decisions now.

Bob Savage replied:
<I completely agree, *and* I believe that this is pretty much a restatement
<of my position as quoted above. One has two primary choices: risk a
>catastrophic loss of the video signal due to the inherent instability of
<support, or suffer a loss of integrity of the signal due to compressive

Tony Gardner continued:
>"Your (unappealing) choices are to let the stock deteriorate without doing
>anything, or pick a format that uses compression". Come on. You don't mean
>that. This is the real world.

Bob Savage replied:
<I do mean it. A choice must be made. It seems apparent to me that often the
<decision will be to reformat using compression because the relative loss of
<signal integrity from compression is outweighed by the risks engendered by
<leaving that signal on deteriorating host media. On the other hand, the
<person responsible for the maintenance of the collection at hand should
<an informed decision, and not "get hung up on single issues" such as the
<instability of the signal support, to the point where they ignore other
<issues such as loss of signal integrity.

I read the original as an 'anti-compression' and single issue missive. I now
see it was not. I dare think we pretty much agree.

Tony Gardner

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