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Ripping Vinyl Via Your Scanner? 537

Posted by chrisd
from the wax-cylinders-are-next dept.
An anonymous reader writes "This site describes a method of extracting audio off of scanned images of vinyl records. Kazaa vinyl swapping is on it's way!" While this method creates exceptionally noisy samples, you can definitely hear the underlying music.
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Ripping Vinyl Via Your Scanner?

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  • Does that exclude Kenny G?
    • by matthewn (91381) on Thursday September 05, 2002 @10:52PM (#4204307)
      No no: Kenny G albums would be vile .
  • by joejoejoejoe (231600) on Thursday September 05, 2002 @10:37PM (#4204241) Homepage Journal
    A device that can extract 1000 words from a picture?

    • by kasperd (592156)
      A device that can extract 1000 words from a picture?

      Why would anybody want that? We all know, that a picture is worth more than 1000 words.
  • Laser Turntable (Score:4, Interesting)

    by ArchieBunker (132337) on Thursday September 05, 2002 @10:38PM (#4204242) Homepage
    Serious audiophiles would simply buy a laser turntable to minimize the wear and tear. Although it probably sounds more like a cd than anything.

    http://www.elpj.com/

    • Re:Laser Turntable (Score:3, Interesting)

      by dfung (68701)
      Back in the days before CDs, I believe there may have been a super-esoteric turntable that tried to do this (or perhaps it was just a press release gracing a CES show).

      It's actually a good idea that doesn't have to sound like a CD. CD music=digitized music. A laser turntable can be used as a precise no-contact ANALOG reader.

      In fact, they're obsolete now, but 12" laserdiscs are doing exactly this - the disk is an optical medium, but the signal on that disk is analog, not digital.

      Now, you can't overcome the limits of the analog recording process, the cool thing about analog systems are that you can keep making them better and better. There is always hope.

      David Fung
      • The turntable exists. I forget who made it, though... Such is the way things are in with high-end audio - companies produce a few examples of one or two really great, hideously expensive products, and then elect to either cut their losses and close shop or declare bankruptcy, before fading completely into obscurity.

        It had a dust-free enclosure within which the magic happened, and tracked/read the groove with a laser.

        From what I can gather, it sounded good, but suffered from problems in that the source material was -not- mastered with such a playback mechanism in mind. Skilled engineers will set up the cutting lathe, the equipment driving it, and the whole recording process with the target audience's anticipated hardware and enviroment in mind, trying to counteract whatever distortion or frequency response blips are likely to be a problem.

        This beast was a bit far off in left field for it to be a factor in any of those educated guesses and adjustments, so there wasn't (AFAIK) any software made specifically to play on it.

        But the biggest problem was dust, scratches, and other imperfections. Since it had no physical apparatus to follow the (very wiggly) groove, nor a needle to push microscopic dust particles out of its path, every flaw on the vinyl surface was very plainly heard and easily lead to mistracking. A case of something being too perfect, perhaps. Rough vinyl -loves- to soak up dust.

        Ask groups.google.com about it. ISTR some discussion of this thing in rec.audio.high-end, once upon a time...

        As for laserdiscs being obsolete, bzzt. The vastly superior video fidelity (compared to DVD, anyhow) and inexpensiveness of hardware and media (thanks, Ebay!) has kept the format kicking, and it's not due to die any time soon. You get Dolby Digital, chapter selection, and most of the other things that most people think were introduced with DVD, with the exception of the stupid fucking animated menus and impossible-to-skip commercials.

        Same reason that Big Ugly Dishes are still fairly common items - sure, people could "upgrade" to some 18" DBS system for cheap (or free), but with a BUD you can recieve the same absolutely perfect AM-modulated analog video that DirecTV gets, -before- it gets routed through another few racks of lossy electronics and MPEG-esque compression, and another satellite, and another recieving dish, and a consumer-level IRD of marginal quality, before finally hitting the TV.

        Some of this old tech is just too cool to die.

        We began these posts by writing about turntables. Talk about ancient tech that just won't go away...
        • You probably mean the Finial Laser Turntable.

          As you mention dust was the big killer, if you bought one of these (hugely expensive) you also need an even more expensive record bashing/cleaning machine to be able to use it.

    • by bgog (564818)
      Did you see the price on these things! The LOW end one is $9500. If the music is only availabe on vynel then for $9500 I'm betting you could get the orignial band to come to your house and play into your computer!
  • But yeah, it's a cool hack.

    I seem to recall in the last days of turntables and vinyl records, when CDs were starting to take over, that some company came out with a no-contact record pick-up that bounced light off the grooves. This is sort of a variation on that idea, except you don't need to spin the record.
  • Vinyl/Vinile (Score:2, Informative)

    by jargonCCNA (531779)
    Do /. editors actually edit? Probably not the first to notice, but it's spelt Vinyl. V-I-N-Y-L.

    Not that hard, folks. Especially when you get it right in the headline.
    • I seriously wish the editors didn't quote story submitters so often. Hell, I don't even care about the poor spelling and grammatical errors. The submitters post the LAMEST jokes and most irrelevant quips.

      Most submissions I see go well until there is a some sort of joke at the end, which is practically a modified clone of the "Imagine a Beowulf cluster of these" joke. Go ahead and see for yourself. Damned submission side-comments!

    • Actually, at 12:09 EDT, the post changed to spell it as "vinyl". But realize that most Italians actually spell the word "vinile". The link is also to an Italian website. The poster is also anonymous, but I'm willing to guess since the site is most likely a hoax, the poster was also the author of the site having some fun.
  • Yeah, but can you rip a fart on your scanner?
  • Quick! (Score:5, Funny)

    by tuxedo-steve (33545) on Thursday September 05, 2002 @10:43PM (#4204261)
    Someone patent this! We can sue this guy and make millions!
  • by saskboy (600063) on Thursday September 05, 2002 @10:45PM (#4204270) Homepage Journal
    Get out the lawyers big bad music companies. There is hell to pay, for this new copyright violating technology.
    I can't wait to start ripping my parent's vinyl. I used to listen to it all the time as a kid, and now my Pentium II is finally advanced enough to play 100 year old technology.
  • Yeah right (Score:3, Insightful)

    by tswinzig (210999) on Thursday September 05, 2002 @10:46PM (#4204277) Journal
    I am releasing no code because it is both sucky and useless (you see, I don't really think swapping scans of old records across p2p networks will become common practice any time soon).

    More like he'd rather get his practical joke on slashdot, and if he supplied the code, it'd be a lot easier to prove it's fake.

    Let's apply Occam's Razor.

    Those music samples could have been generated by software that reads stitched together images of scanned vinyl records.

    Or they could be just regular samples of music taken off a record/cd/tape and run through a static-izer for effect.

    Which is simpler?

    Let's see the code, please...
    • I can't believe the amount of morons that have fallen for this story yet. The explanations the guy gives are shoddy, and logically it makes no sense.

      Not only that, but he's extrapolating a higher amount of data from a smaller amount, and that just does not work people! Listen to that MP3 on his site. That is just a recording of a record playing.. there are no hideous artefacts or giant gaps.. all of which would be expected with such a crazy new idea like this. It reeks of a hoax.

      Just because it's not April 1st doesn't mean you haven't been fooled, folks! I have to give the guy credit for trying though.
    • Re:Yeah right (Score:3, Informative)

      by hopews (450546)
      After visiting a pdf on LP technology [jhu.edu] and finding that LPs have around 290 lines per inch, and 45s 160 or so, it would seem that a reasonable scanner (say 1200 dpi) would pickup 7 pixels per track on a 45. This would make horizontal (along the plane of the record) resolution quite poor. However, if he's only tracking the vertical component (perpendicular to the plane of the record), and the varying heights translate well into light to dark gradients, perhaps there would be enough information to produce some bad sound. I too would like to see the code and perhaps some of the source images.
    • I'm with you. If anybody believes this I'll be happy to send you a recording of the asteroid impact that killed off the dinosaurs. I just ran an Antarctic ice core sample over my flatbed scanner and converted the compression-induced diffraction patterns into sound waves, using high school algebra and a TRS-80.
  • by isdnip (49656) on Thursday September 05, 2002 @10:47PM (#4204281)
    The original author failed to research how vinyl records work, something that "everybody" knew 20 years ago, before CDs.

    Now to see if my memory still works. Mono LPs used horizontal modulation; the needle moved back and forth within the groove. Stereo can be viewed two ways. Vertical is difference (L-R), horizontal is sum of the L+R. Viewed differently, the two diagonal walls of the groove are the two channels.

    A flatbed scanner can only see the horizontal, so it might work a bit with mono, but it won't work too well! However do note that some very, very expensive ($10k+?) new turntables actually do use optical "needles" to track the groove without touching it. Talk about low tracking force!
    • Now to see if my memory still works. Mono LPs used horizontal modulation; the needle moved back and forth within the groove. Stereo can be viewed two ways. Vertical is difference (L-R), horizontal is sum of the L+R. Viewed differently, the two diagonal walls of the groove are the two channels.
      The reason that horizontal is l+r (the volume levels of l and r are half the levels of the real signal L and R) and vertical is l-r, rather than just storing L and R, is for backwards compatibility. l+r is basically what the recording would sound like had it been recorded in mono. In a stereo system L and R can be simply reconstructed from l+r and l-r (L=l+r+l-r, 2R=l+r-(l-r)). In a mono system l+r is played.
      A flatbed scanner can only see the horizontal, so it might work a bit with mono, but it won't work too well!
      Theoretically you could get a mono signal out of even a stereo recording. I'd probably try partially filling the tracks to a constant depth with some sort of white material, then scanning it at very high resolution. But I don't know if you could make the whole process accurate enough to actually work. Certainly I seriously doubt it would be doable the way that guy claims he did it.
    • Those laser turntables are manufactured by ELP, and the website is here:
      http://www.elpj.com/

      "New Low Prices!"
      Sure... I can still buy a cheap car for the cost of one...
  • real people (Score:3, Interesting)

    by squarefish (561836) on Thursday September 05, 2002 @10:48PM (#4204282)
    ok, so I'm aging myself- but many years ago on "Real People" they had a guy that could recognize an album or song just by looking at the grooves, his specialty was classical, but he knew everything and could easily identify the song just by looking at the grooves. This is basically doing a similar type of thing.
    • I'm not impressed, but I'll have to "age myself" too to explain why. I knew people back in highschool who recorded stuff off the air, and never labeled their tapes. They just knew the music by the brand of the tape, how dirty or scratched the plastic was, where it was thrown last, etc. I've seen that done with collections of 100 or more tapes. OK, it's not quite as impressive, but the leap to different patterns in the vinyl isn't that great.

  • does it take more bandwidth to send jpgs or mp3s of your record collection? oops i guess jpg and mp3 *both* have ip issues... I got to switch from mp3 to png... ogg is for pussies
  • by puto (533470) <theflatline@yahoo.com> on Thursday September 05, 2002 @10:50PM (#4204295) Homepage
    I have a Dual direct drive turntable I bought in 1986 with a diamond stylus. It sounds great and I have 'ripped' all my LPs to mp3 a long time ago. Didn't need to stick em in my scanner, didn't need to stitch any images together.

    Besides I would not stick any of my 12 maxi singles of 1980s Billy Idol in the scanner to be scraped against the glass. ;).

    My NAD stereo has been faithfully updated over the years but the turntable remains the same. And I do use it on the odd occasion and sometimes do pick up an ablum at the flea market.

    Puto
  • Cool, but... (Score:2, Informative)

    by Cyno01 (573917)
    this is really cool and all, but whats the point, if you really dont care at all about quality then this may be a quick option for converitng your collection, but if you still have vinyl you probabably care enough to plug your turntable into the audio in jack on you computer
  • by Anonymous Coward on Thursday September 05, 2002 @10:55PM (#4204319)
    If you scan it backward, are there satanic messages?
  • by theNote (319197)
    Hypothetical Question:

    Lets say this is for real (not really sure about that one)

    Lets also assume it eventually extracts 100% clear as a bell.

    Would it be legal to trade/sell pictures of albums?

    • No, of course not.

      MP3s are not like-for-like copies of CDs, they're extremely lossy, and you only get a tenth of what's on the CD.. but.. you can still get busted for swapping them! I believe the copyright laws specify that any 'likeness' to which a third-party could associate with the original, is covered as such.

      Ditto for music encoded within images, though this is a hoax.
  • computer media? (Score:2, Interesting)

    by cosyne (324176)
    Can this be done with computer media? Could you just scan in two halves of a broken cdrom and extract the info? (Or has the NSA been able to do this for years and not told us about it? They just dig the CD shards out of your trash, reassemble the electron micrscope output, and read off the bits.) He said he had to scan the record in multiple sections, so it might not matter if those sections are all attached to each other.

    On a related note, is there any technology for using a high res laser scanner to read records? It might actually sound decent.
    • I think I remember seeing something like this on KnowledgeTV(damn fine station until my cable company canceled it). I'm pretty sure someone like DriveSavers can recover data from broken cdroms, and if they can do it I'm sure the government can.
  • Heh. Nice Hoax!

    I love the part where he draws out all these superficially fancy-looking diagrams modelling 3d space but he doesn't bother to even use a compass for his angle drawing/measurements so his record looks like it was drawn by a 3 year old...

  • The best way to remove the noise is to not ADD THE NOISE when you produce your hoax! :). Very clever but this is a big steaming pile of it!
  • Take mp3 files, generate a 3D polygonal representation of a record, then do a physics simulation with a virtual needle, also made up of 3D polygons. Take the vibrations of the needle and simulate the conversion from kinetic to analog electrical energy. Then digitize the electrical signal and play it out the sound card. Then you could just swap mp3D files on your P2P net of choice...

    obDMCA: rot13 the poly data and call the FBI when the RIAA circumvents it...

  • agfa, HP, epson, canon, beware...

    your scanner now is officially a copyright circumventing device, please upgrade firmware to prevent illegal vinyl scanning or else we will use the DCMA to it's full extent :)
    • your scanner now is officially a copyright circumventing device,

      Your scanner was already a copyright circumventing device; how do you think all those bootleg books get on the web? Not all copyright is sound, you know.
  • by AnalogBoy (51094) on Thursday September 05, 2002 @11:46PM (#4204532) Journal
    But if they would just pass the headline through MS Word once, 95% of the bitching on slashdot would be either silenced or replaced with bitching about using MS Word to check the spelling of the headline. :)

  • by td (46763)
    A vinyl LP is 12 inches in diameter, and has a label area in the middle that's about 4 inches in diameter. So the area containing the spiral groove is about 4 inches wide. That's about 10 centimeters. An LP side typically has a little more than 20 minutes of music on it. It rotates at 33 1/3 RPM, so the groove spirals around roughly 667 times. So the width of the groove is roughly .01/667 meters, which is 150 microns. The signal (on a monaural record, stereo is more complicated!) is recorded by wiggling the groove from side to side in that 150 micron space. To reproduce a signal whose dynamic range is 90 dB, the smallest excursions have to be roughly 1/30000 of the maximum amplitude. 150/30000 microns is 5 nanometers.

    Think your scanner has that much resolution? Guess again -- 1200 dpi is roughly 21 microns, off by a factor of 100.

    Note that 5 nanometers is way smaller than the wavelength of visible light (roughly 750 to 350 nm), so those laser turntables everyone is talking about don't work very well either, unless they've got x-ray lasers in them.

    • Whoever modded this up needs to use some common sense. A record groove that's precise to under 5 nanometers? Sorry, that right there should tell you that this is lacking somewhere. Perhaps some people don't understand that the needle on your record will NOT, no mater how good it is, pick up vibrations caused by a few nanometers of change because that is literally just a handful of atoms!

      Now, where the analysis is wrong is a tougher question for me. I'm guessing, however, that it has something to do with the fact that the author assumes that the info isn't encoded on a logarithmic scale. You do, after all, have to have a very special amp to use a phonograph.

      b.c
      • There's also no way that a vinyl LP has anything like a 90dB dynamic range. More like low-to-mid 50s, maybe approaching 60dB with a virgin pressing on high-quality vinyl. That's a factor of 1000 to 10,000 right there -- bringing the lower limit into the 5 micron range.

        Furthermore, the spacing between grooves (or rather, successive revolutions on the same spiral groove, to be pedantic) isn't uniform. The grooves are spaced closer together during quiet portions, and further apart during loud parts, to give more space to larger-amplitude waves. (The second photo in the article gives a great example of this.)

        This can cause problems with really loud recordings. I know of at least one recording of Tchaikovsky's "1812 Overture" (the one with the cannons) that came with a warning about setting the tracking force appropriately lest the wild excursions during the finale cause the needle to jump the track. (It also had a warning about making sure your speakers had overload protection.)
    • "So the width of the groove is roughly .01/667 meters, which is 150 microns."

      Well, you meant to say .1/667, but it's still 150 microns.

      "To reproduce a signal whose dynamic range is 90 dB, the smallest excursions have to be roughly 1/30000 of the maximum amplitude. 150/30000 microns is 5 nanometers."

      First of all, the system isn't linear. Think about the sizes you're talking about. And 90dB?
      But there's a more important issue: your complaint here would make sense if the software was tracking the groove movement by pattern recognition. But that's not what was suggested here; it's using the light levels along the grooves in the scans to estimate the surface angle and extrapolate the position. All the picture we need for that is a view a few pixels across on the groove. Of course, there still could be an issue with the lack of intensity resolution on the scanner... But since even my entry-level $130 Canon can do 36-bit colour optically (presumably yielding a 12-bit greyscale), you might just be able to shop your way round it.

    • I think you're off somewhere... Let's try working the math a different, simpler way.

      In the inner track, we have 4 inches * PI = about 12 inches. 33 1/3 RPM = 0.5 RPS, or about 6 inches of record per second. 20,000 cycles per second frequency = 20,000 grooves every 6 inches of record or around 3,000 grooves per inch. Based on that, it's still beyond a 1200 dpi scanner, but it's not the insane tolerances you're speaking of, either.

      Now, that's for 20,000 Hz. The question is whether a 1200 dpi scanner could pick up enough data to get a very low quality signal.

    • A vinyl record has a label of typically 3 to 4 inches, and it is safe to assume the groves are 4 inches on either side. At 1200 dpi, this corresponds to 4800 dpi. A record that runs for 22 minutes has 720 groves across a given radius, and therefore a grove is 4800/720 or 6.66 pixels per grove.

      In the course of a minute, the record rotates 33 1/3 revolutions, or 12,000 degrees. This is 200 revolutions per second, or 12' per millisecond.

      On a circle of radius 2400 dots, one millisecond corresponds to 8.375 pixels. Typically, it's closer to 24 pixels.

      So, what you are essentially looking at is 24*6.66 = 160 pixels per millisecond at the minimum, and an average closer to twice this.

      While one can not expect to get cd-quality audio from such a processing, it is well within the realm of possibility to produce something at 9kHz, similar to the old AM radio quality.

      Certianly LP manufacturing has come a long way. The technology to make high quality 33 1/3 appeared around 1947. Before that the 45 and 78 dominated, and low quality 16 2/3 rpm. Microgrove stereo technologies appeared around the 1960s, and towards the end of the seventies and early eighties, there was some optical pickups.

      Dollar for dollar, the LP still sounds better than the cdrom, purely because the digital noise, while not audible, provides a harsh overtone when compared to the vinyl.

      On the other hand, with a bit of practice, one can follow the music by looking at the wriggles on the grove. I know I could identify music from the grooves.

      The other trouble is that shading and colour carries information as well. So while there are 160 pixels per second, there may well be more information when colour is added into the picture.

      Given that his audio samples are consistant with the calculated data information to be found.

      So the stuff lines up pretty well, I should imagine.
    • >To reproduce a signal whose dynamic range
      >is 90 dB, the smallest excursions have to
      >be roughly 1/30000 of the maximum amplitude.

      That may well be the case, but the vinyl LP tops out at about 60db of dynamic range. And that's with an audiophile virgin vinyl pressing produced on the finest equipment. 40-50db of dynamic range is the best you'll get from most discs & equipment, and even then not at all frequencies. When it comes to consumer audio, only the digital formats - DAT, MiniDisc, CD & its offspring - can deliver 90db of dynamic range. Although I suppose VHS Hi-Fi and quality cassette decks with Dolby S can come pretty close.

      >the width of the groove is roughly .01/667
      >meters, which is 150 microns.

      This page [aardvarkmastering.com], which purports to be the text of an RIAA bulletin from 1963, lists all the standards for phonograph records. According to it, the grooves of a stereo record are at a minimum .001" wide, which I believe is 25 microns. Of course, they can be much wider than the minimum - and in fact, have to be, if you want to reproduce loud, low bass.

      For comparison, CD "grooves" (tracks, really) are 1.6 microns wide, according to this page [washington.edu].

      Each pit is approximately .5 micron wide. DVD tracks and pits are roughly half as wide as CD's (and the pits are much shorter). So clearly lasers wouldn't have any trouble seeing into the groove of a vinyl record, but I'm not sure how the laser turntables are picking out details smaller than about .1 micron. Perhaps the extraordinary cost of the laser turntable units - about $10,000/ea. and up - confirms it's not easy to read a record using light! Could they be using UV lasers or some other esoteric technical tricks?

      Whatever they're doing, they got a great review [stereotimes.com].

      I agree though that there's no way a home scanner could suck enough detail off a stereo record to reproduce much of anything. 1200dpi isn't even close to what you'd need.
  • Since when.... (Score:3, Interesting)

    by dcigary (221160) on Thursday September 05, 2002 @11:50PM (#4204547) Homepage
    ...does an interplotation of images to sound produce regular friction noise? (The background noise that has a regular beat to it).

    C'mon. There's lots of filters out there that will introduce these types of effects into a sound file.

    Hoax.

    • Actually, because of the low resolution and the fact that the recordings are pre-emphasized, I'd expect to hear severe aliasing in the resulting audio. I vote "hoax" too...
  • looks possible (Score:5, Informative)

    by alizard (107678) <alizard@noSpAM.ecis.com> on Thursday September 05, 2002 @11:53PM (#4204552) Homepage
    These numbers are EXTREMELY approximate, I just wanted to see if his claims are possible. They are.

    Standard rotational speed = 33 1/3 RPM

    12" record

    Circumference = pi * D

    33.3RPM /60 ~ 0.5 R/second

    12" * pi ~ 37" circumference.

    0.5 * 37" = 18.5"

    18.5 * 600dpi = 11,100 samples per inch, which gives a Nyquist limit of 5550Hz... a 2400 dpi or better might actually give full audio bandwidth, though in this case, the higher the better, since the area available for sampling decreases towards the center of the record, and for really high fidelity sound, more than 2 samples at 20K are necessary.

    His model for how the record was encoded is *wrong*. The RIAA method of stereo modulation (back when they were mostly a standards organization) places the amplitude information on each wall of the V-shaped groove. It is intended to be picked up with a stylus connected to a something in the form of an Y , with channel information picked up by coil or magnet or other means attached to each upper leg of the Y.

    Fixing his model should result in drastically improved performance if he's extracting stereo information. Cleaning the record would also help a lot.

    His project actually *is* worth doing. An optimized algorithm should allow anyone or a museum with a good scanner to turn his vinyl (SPELLED CORRECTLY) collection into decent quality Red Book or MP3 tracks without any further damage to the records. The basic problem is to linearize the relationship between 16-24 bit gray scale information of reflected light and the depth modulation in each groove.

    The suggestion of using software to extract 3D information from the grooves posted elsewhere is a good idea, but this is a good start.

    Cool hack.

    • For someone to go through this much effort without finding out exactly how the grooves are cut in the first place left me scratching my head too. There's quite a potential for collecting music from records here.

      On the other hand, it's been done by others. There's an extremely expensive turntable that uses a reflective laser pickup instead of a stylus/cartidge to read the record. Great for museums. There have also been interesting SF stories about similar ideas in the past.

      However, an entire record read with a common scanner? Cool! Even better, it's conceivable that image manipulation could repair certain defects in records far better than audio filters (analog or digital).

      Neat!
    • I hate to LART someone I don't know, but...

      This poster has no clue whatsoever. They are either incredibly high, making a joke that simply isn't funny, or incredibly stupid.

      Very possibly more than one of the above factors is at work here. ...and the people who foolishly moderated this as INFORMATIVE are almost assuredly being affected by at least two of the above factors.

      Factual information to back up my claims, in simple and easy to understand words:

      Needle grooves are not just squiggly lines like waveforms in your copy of WinRecord. The groove itself is going to be v-shaped, and can swing the needle both inboard and outboard, as well as rotate it slightly. Even a 2400 dpi scanner is not going to be sufficient to read that kind of subtlety... and let's not forget the other two factors here... the vinyl is both SHINY and BLACK.
      When was the last time you tried to scan the cover of a black vinyl three-ring binder? Could you see the naugahyde (sp?) pattern in the scanned result?

      Pffft.

      Step _away_ from the bong, people.

    • Re:looks possible (Score:2, Informative)

      by femto (459605)
      I wonder if the sample rate could be increased by interleaved sampling?

      To do this, one might scan the record multiple times at 600dpi. The information from the multiple images could be combined to interpolate the missing samples. Same priciple as 'interleave' mode on an oscilloscope. I guess it might also be necessary to deconvolute the image with the impulse response of the scanner.

  • My turntables are piped straight in to my studios master mixer, so instead of getting a crappy signal based on an imperfect scan, I can just record the track and use one of about a hundred different pieces of software to denoise the track, though most of my stuff is pretty new and has very little noise anyway. Yeah... great.
  • by Animats (122034) on Friday September 06, 2002 @12:38AM (#4204683) Homepage
    This is kind of neat, although, as another poster pointed out, it's not going to reach down to low-amplitude components of the audio. But it could sort of work.

    Much of microscopy work, which this is, involves fooling with the illumination direction vs. the viewing direction. Getting that right is a big part of doing it at all. This guy had to scan the record in four quadrants to get some halfway reasonable result. Obviously, you'd like a rotational scan, like a turntable with a stationary scan arm. The amusing thing is that you could read an entire vinyl record in one rev. Now, at last, the 1000x LP player!

    Incidentally, the recording system for stereo LPs is called "45-45 Westrex", because there are two perpendicular tracks recorded 90 degrees apart (at +45 and -45 from vertical). Mono records, which have no vertical component, are thus backwards compatible. If all you can read is the horizontal component, you get a valid mono signal.

  • recording audio tapes off of the C= 64's datasette :)

    I think it was like 2-bit (no pun intended) audio. You could hear the music there as well, but you couldn't do anything like rock...it would just become noise. But, "spoken word" recordings were ok. I remembered having a disc that contained "historical recordings" (JFK, Nixon, etc). If you didn't expect too much, it was actually kind of fun :)

    But my question is, how does this guy ever expect us to belive that these recordings were done in the method decribed if he won't release the code...
  • Hey, has anybody tried disabling the light tube on a flatbet scanner and using some alternative light source mounted at an angle? I don't mean necessarily to scan a vinyl record, just in general on interesting surfaces. Skin, cloth, paper, bark, I don't know. If I can find a working scanner to rip apart I will give it a try and report back.

    Oh, uh, I mean, I DID do that, yeah I did it already. Last week. It was easy because I'm a genius. But uhhh, I'm not releasing any pictures because they're lame and nobody would be interested in swapping them on Kazaa.

    Seriously, has it been done?
  • I remember this guy who was on a Saturday night TV show in England back in the 80s (it was a show hosted by a magician... my memory has been fried by years of guinness so I can remember his name... Paul something I think) who litterally could look at any vinyl classical record and tell you what it was. His photographic memory along with the patterns that a vinyl disk would make under intence light was what allowed him to freak me out at the tender age of 8.
  • The reason people use LP's is because they prefer analog reproduction, instead of the (down) sampling done by the digital format. These guys clean their power so it's perfect sine waves and then use vacuum tubes to amplify thhe signal. I've listened to one rig like this and I have to admit that it sounded pretty darn good. What's the point of doing a crappy scan of an LP if you're going to digitize the picture, mangle it through a bunch of filters and try and reproduce the sound.

    I'm still not convinced that you can get decent sound out of a 1200 dpi scan of the LP. You'll only get two or three 32bit dots on the actual track. track speed of 9-18" per second, at 1200 dpi and you get 16800 x 3 dots, or about 50k dots per second. 60 Mega pixels of really really noisy, hard to work with information.

    BTW, the ELPJ [elpj.com]'s laser turntable claims to be completely analog. If it were digital, they'd probably lose 70% of their market. After, the reason you have LP's is because you want the analog sound.

    EnkiduEOT

  • Several people have mentioned the ELP laser phonograph that costs like $10k. There are some plans and kits available on the net for those laser listening devices that you point at a window to hear conversations inside. I wonder if one of these could be modified to read LP's. You'd likely have to get a more focused beam, and you'd need a couple of them to get stereo sound, but it might be a cool project.
  • Now the first audio sample is the reference recording. Great. Nabbed off the record. The rest are obviously EQed, and Modulated multiple times. Most likely run thru a stutter or fuzz as well. This is very obvious in the first second of the files. Nothing that a demo of Sound Forge couldn't do, or any number of audio programs out there.

    If the had guy released code, I'd be EQing, fuzzing and modulating a different tune. Until then, a definite fake. One that I wish were real :(

  • If I were going to try this (and don't tempt me -- the only LP I have handy is Alice's Restaurant) I'd disable the stepper motor in my scanner and turn the record so that it passed over the scan head instead. That would save you the stitching step...
  • People have tried to look for similar patterns in the surface of oil paintings. They hoped that ambient sound might vibrate the canvas, and the artist's palette knife would act as the recording needle. I don't think it worked: I have had a quick dig on the Web, but can't find any mention of it.
  • by Rutje (606635) on Friday September 06, 2002 @04:10AM (#4205195)
    I got hand of the software. Adjusted it a bit so it also works with a digital video cam. I place the cam above my turntable and it converts the video signal in realtime to audio. Even scratching works!
  • by alizard (107678) <alizard@noSpAM.ecis.com> on Friday September 06, 2002 @04:44AM (#4205263) Homepage
    http://www.aardvarkmastering.com/riaa.htm [aardvarkmastering.com] contains the physical dimensional specifications for 33 1/3, 45, 78 RPM records.

    http://arts.ucsc.edu/ems/music/tech_background/TE- 19/teces_19.html [ucsc.edu] contains basic information on how the LP record works. I think the most important thing for the experimenter is called RIAA equalization, in order to limit the physical motion of the recording stylus that cut the record, bass was reduced and treble increased in a very precise way, in order to reproduce the original sound, the opposite must be done.

    The RIAA equalization curve is a plot of amplitude boost/cut vs. frequency. Apply its inverse to the raw analog signal(s) that come out of your signal processing.

    You can find it at http://www.tanker.se/lidstrom/riaa.htm [tanker.se].

    Oh, and CLEAN THE RECORD BEFORE DOING THIS. The info in Part 14 of the rec.audio.* FAQ is as good a place to start to find out how as any.

    Have fun and feel free to let me know if you get anywhere.

    You might also want a look at my other post to this thread [slashdot.org].

  • by Anonymous Coward on Friday September 06, 2002 @06:19AM (#4205435)
    Some clarifications:

    I am sorry so many of you thought this page was a hoax only
    because no source code was supplied (I'm sure you'll all agree, now that
    you can see the code, that it is both straightforward and crappy).

    I guess I didn't do enough on the actual explanation side either.
    The whole thing was done in a couple of late nights so I didn't really
    have much time to gather all the technical details concerning phonograph
    modulations. Moreover the "archeological" reverse-engineering aspect was part
    of the fun.

    I now know (thanks to some great replies) that the horizontal modulation (the only
    one I did decode) is not a whole channel in itself but merely a delta between
    the h-modulation and the depth-modulation which I did _not_ decode.

    Some repliers seemed to be a tad confused as to what recordings were
    the actual decodings. I'd like to stress that gramophone3.mp3 is a recording
    while the rest (dneedle*) were decoded from the image.

    Have fun,
    Ofer Springer

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