Text 5989, 50 rader
Skriven 2010-03-19 10:21:03 av Björn Felten (2:203/2)
   Kommentar till text 5969 av Robert Bashe (2:2448/44)
Ärende: Historical recordings
=============================
 RB> what it was. In principle, you're right, but in practice there are still
 RB> major hurdles.

   Those hurdles have already been passed. It's only a matter of resolution.
Yesterdays photo scanners were relatively low resolution, today's are not.

   Albeit we are not yet where you can take one photo scan of the entire
record, we can still have e.g. a narrow band scanner that is rotated over the
record once or twice and get the needed resolution.

   Also, the computer power to do the proper Fourier analysis of the three
curves (bottom, left and right) are available, and that is paramount for
getting the proper conversion of wave forms to audio.

 RB> The only place that really uses this procedure for historical recordings
 RB> is the Library of Congress in the States. And apparently, with the kind
 RB> of equipment and personnel they have, the results are acceptable to
 RB> good. But not even normal museums have that kind of equipment and
 RB> personnel, and the Library of Congress doesn't do work for others, in
 RB> particular not for private persons.

   As I said, that sounds like yesterday's technology. Today even personal
computer power exceeds the power of the most powerful main frames from just ten
years ago, not to mention photo scanner resolution.

 RB> No, it's just not as easy as you appear to think. I personally think the
 RB> best option is to wait for laser stylii to become affordable,

   Two of the major problems with the laser styli method is:

   A) You still have to play the entire record (45 minutes or so).

   B) You are still vulnerable to grove damage caused by old mechanical styli
having passed in the grove many times. You simply can not direct the laser beam
to safe areas of the grove in a reliable way.

 RB> originals with physical contact. What you also have to consider is that
 RB> old records are often damaged, and even a good playback file would have
 RB> to be expertly restored to be intelligible. Not many people are capable
 RB> of doing such work.

   Fortunately, it's very rare that the bottom or the edges of the groves have
been damaged. It's almost always the middle of the sides of the grove that
takes the hardest hits from the mechanical styli. And, obviously, photo
scanning a record doesn't damage it the slightest, so you can repeat the
procedure as many times as you like without causing any damage even to
historically valuable recordings.

--- Mozilla/5.0 (Windows; U; Windows NT 5.1; sv-SE; rv:1.9.1.8) Gecko/20100227 
 * Origin: news://felten.yi.org (2:203/2)