[Table of Contents]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

RE: [AV Media Matters] Digital audio file formats

Dear All,
    I am replying to an early response on this subject, because I consider
you have *all* missed two very important points in the discussion so far.
    Here, at the British Library "National Sound Archive", I consider our
job is to preserve the original (or the *intended* original) *Sound*, rather
than any physical artefacts. My regular readers will know that we are doing
very little such work, and then only with analogue media which are expected
to self-destruct if we don't. But as someone else remarked, I am horribly
aware that there is much more in such recordings than we can recover with
present-day techniques. So the work we are doing at present is essentially a
"once-and-for-all" process. (We are of course keeping our originals in case
a new process - and the necessary pound notes -  come along, so we might
have another try).
    My first point is that it is *vital* to document all the processes which
have been used to "archivally digitise" an analogue recording, so future
historians will know how we've interpreted the analogue version available to
us. As a simple example, consider the problem of playing-speed. There are
many techniques which can be employed to set the playing-speed of an
analogue recording satisfactorily (some of them self-contradictory), so the
result may depend on the assumptions made by the analogue-to-digital
operators. All this information needs to accompany the digitised version, so
future historians will understand our thought-processes.
    This may mean anything from nil metadata to some megabytes of metadata.
Whilst I can see the advantages of "access versions" for Rod Louey-Gung's
situation, he will be aware that the compressed digital version suffers in
the presence of hiss from a 9.5cm/sec tape, and I am being afflicted with
this very problem myself. A skilled audio engineer is necessary to do a
subjective tradeoff between (say) hiss, compression-artefacts, and other
"distortions" of the sound. All the lossy compression systems we have tried
require this.
    I consider this intervention is vital, if a Technical Section such as
mine is to retain credibility among the taxpayers who pay my salary!
Peter Copeland
Technical Manager
British Library National Sound Archive

-----Original Message-----
From: Rod Louey-Gung [mailto:rlg@integrated-media.com]
Sent: 29 June 2001 06:29
To: AV Media Matters
Subject: RE: [AV Media Matters] Digital audio file formats

One of the questions I think needs to be answered is the reason for the

Is it for preservation of the audio content. ie. being able to playback the
recording so that the speech can be understood, which could be in a
compressed .wav format, or is it an "as high as possible quality" recording,
which should possibly be at the new DVD-A format.
There are obviously differing storage requirements for both these formats.
I have been discussing the archival of Hansard recordings with various
clients for some years now, and I must admit that there has been a general
lack of committment on the part of legislators to make decisions in this
area. Obviously, the fast paced technology changes, and the lack of real
meaningful data on "archival" mediums have helped in the lack of decision
However, my suggestion has been that at the very least a compressed .wav
recording should be archived, at this stage onto CD (this being the most
cost effective medium). This is not my ideal "archival" medium, but better
than nothing.
Our job has been made slightly easier, as all Hansard is now recorded using
the FTR Gold software package, which automatically archives onto both
compressed CD and central server.

             Rod Louey-Gung
         Integrated Media Pty Ltd
       Tel 61-8-8945-3555 (Darwin)
      Tel 61-8-8299-9800 (Adelaide)
           Fax 61-8-8945-4003
         Vision 61-8-8945-1350
           Mobile 0419-553333
     email: rlg@integrated-media.com
      www: www.integrated-media.com

The information contained in this e-mail is confidential and may be
legally privileged. It is intended for the addressee(s) only. If you
are not the intended recipient, please delete this e-mail and notify
the postmaster@bl.uk : The contents of this e-mail must not be
disclosed or copied without the sender's consent.

The statements and opinions expressed in this message are those of
the author and do not necessarily reflect those of the British
Library. The British Library does not take any responsibility for
the views of the author.

[Subject index] [Index for current month] [Table of Contents]