On 21/06/2012 20:34, Michael Biel wrote:
> Many restorers use many more than one copy of a record in their
> restorations. Jon Samuels and I brought this up at the ARSC Conference
> when the new people at Syracuse's Belfor Archive discussed surplussing
> copies beyond two using only visual grading. The two of us along with
> Seth Winner were still discussing this, with the two of them saying how
> they and others sometimes use ten or more copies. Not so much for
> simultaneous playing -- but as stitching sections together as Randy
> discusses with film restoration. But as Don Cox said concerning
> simultaneous playing:
>
>> The two groove walls of a mono record already do what you suggest, but
>> twenty copies might be better than two.
> Similar to what Jerry Hartke suggests, back as far as WW II, monitors of
> international broadcasting would often use two receivers listening to
> the same station's multiple transmissions on different frequencies with
> binaural headphones -- the audio could be fused in the center while the
> noise stays separated out into the two different ears. This can also
> work playing back some of Tom Fine's examples of worn Paramount blues
> records. If one copy is available, play it in stereo/binaural. If two
> copies are available, play them locked together, maybe using the four
> available groove walls in separate channels.
>
> This technology is already available for aural listening -- we use the
> algorithm in our brain!
>
> But getting back to the non-groove pictures, I opined that fine grain
> photos of 700,000 78s exist in the Rigler-Deutsch Record Index films but
> that they all have light-wedges from point lighting instead of the ring
> lighting I had suggested. I wonder if Patrick and his technological
> wizards might try to see if there is an algorithm that might be able to
> even the lighting problem out. Since the same camera and light sources
> were used on all of the records, maybe that is possible. (And thanks to
> Chuck Howell for saying he would have listened to me!! I wish you had
> been a part of the AAA back then!)
>
> Mike Biel [log in to unmask]
>
>
> -------- Original Message --------
> Subject: Re: [ARSCLIST] audio from pictures
> From: Jerry Hartke <[log in to unmask]>
> Date: Thu, June 21, 2012 10:48 am
> To: [log in to unmask]
>
> This technique has been used for decades by our government to extract
> information from noise. One example is submerged submarine
> communications
> where the noise level can exceed the signal level. I believe that one
> method
> is called autocorrelation. I do not have references, but perhaps some of
> the
> older methods have been placed in the public domain.
>
> Jerry hartke
>
>> -----Original Message-----
>> From: Association for Recorded Sound Discussion List
>> [mailto:[log in to unmask]] On Behalf Of Randy Riddle
>> Sent: Thursday, June 21, 2012 10:00 AM
>> To: [log in to unmask]
>> Subject: Re: [ARSCLIST] audio from pictures
>>
>> I've thought for some time that there's already a way to do this with
>> at least some recordings.
>>
>> For years, film restorers have used multiple prints of films, taking
>> the best quality sections from each that survive, sometime
>> substituting small sections in a print that has been damaged.
>>
>> Why couldn't that be done with recordings where multiple copies survive?
>>
>> Basically, what the software would do is let you take multiple sound
>> files sourced from different copies of the same record. Each will
>> have been damaged and degraded in different ways and have different
>> patterns of noise.
>>
>> The software, after synching the recordings, would compare them and
>> "toss out" the noise and keeping commonalities between the copies.
>> The more copies of the recording you have available, the better the
>> result might be, at least theoretically.
>>
>> Why couldn't this work?
>>
>> rand
>>
>> On Thu, Jun 21, 2012 at 9:24 AM, Tom Fine <[log in to unmask]>
>> wrote:
>>> Hi Steve:
>>>
>>> I agree with you in general, but I'm talking about recordings where
>> analog
>>> playback has produced poor results -- for instance the badly worn and
>>> super-rare Paramount blues records. No transfer I've heard using analog
>>> playback and whatever digi-trix the producer decided to use has produced
>>> very good-sounding results.
>>>
>>> I think the pot of gold at the end of the research rainbow for non-
>> physical
>>> playback of grooved media is the ability to "erase" all the noise that
>> comes
>>> from the media itself, and of damage to the media. Then, in theory (and
>>> sometime in the future) you'd just be reproducing the information
>> originally
>>> cut into the groove.
>>>
>>> For now, I wouldn't worry about your transfer business (or mine) being
>> under
>>> dire threat. But I hope I live long enough to see the day when putting a
>>> needle to an old groove for critical playback or transfer is considered
>>> obsolete.
>>>
>>> -- Tom Fine
>>> From: "[log in to unmask]" <[log in to unmask]>
> Date: Thu, June 21, 2012 12:44 pm
> To: [log in to unmask]
>
> Meanwhile, there's the nagging question of what to do with unique
> artifacts.
>
> An algorithm that can tell the difference between sound (coherent) and
> noise (non-coherent) would be great. Or maybe a really sensitive noise
> gate that can select pixel by pixel, or the audio equivalent. Imagine a
> spectral view of a wav file and a process for eliminating everything
> below a certain threshold on a pixel by pixel basis. Never mind the
> slices of the spectrum. Only that which is above the threshold remains.
>
> With the Berliner file in question, the voice fades somewhat at moments
> leaving the noise as loud as the voice, or louder.
>
> The problem for me is that I don't speak German so I don't what I'm
> hearing anyway.
>
> joe salerno
>
>
> On 6/21/2012 11:34 AM, Don Cox wrote:
>> On 21/06/2012, Randy Riddle wrote:
>>
>>> I've thought for some time that there's already a way to do this with
>>> at least some recordings.
>>>
>>> For years, film restorers have used multiple prints of films, taking
>>> the best quality sections from each that survive, sometime
>>> substituting small sections in a print that has been damaged.
>>>
>>> Why couldn't that be done with recordings where multiple copies
>>> survive?
>>>
>>> Basically, what the software would do is let you take multiple sound
>>> files sourced from different copies of the same record. Each will
>>> have been damaged and degraded in different ways and have different
>>> patterns of noise.
>>>
>>> The software, after synching the recordings, would compare them and
>>> "toss out" the noise and keeping commonalities between the copies.
>>> The more copies of the recording you have available, the better the
>>> result might be, at least theoretically.
>>>
>>> Why couldn't this work?
>>>
>> Wow from slight off-centring would be a problem, but maybe Capstan could
>> deal with that.
>>
>> Otherwise, the stitching algorithms used for images should be easily
>> adaptable.
>>
>> The two groove walls of a mono record already do what you suggest, but
>> twenty copies might be better than two.
>
Chris Hicks of Cedar did his doctorate on just this question of multiple
copies. When the algorithm could be persuaded to work, the results were
much as you would expect - enhancement of the correlated wanted signal
and reduction of the random noise. Unfortunately, pulling the recordings
into good enough sync for artifacts to be negligible was a frustrating
and difficult business, even with recordings made one after the other
(by me, as it happens) on the same kit on the same settings on the same
afternoon, with meticulous centring. The minute geometrical differences
between different laminated pressings were enough to throw things
continually out of register. The example produced, however, is a
tantalising glimpse of what might one day be possible.
Whenever I do a master of the QHCF Decca of "Souvenirs", I use three
copies from the shelf - one for the very start, one for most of the side
and one for the last few turns where the others are afflicted with
"Decca scrunch".
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