QRTape – Audio Playback from Paper Tape with Computer Vision (2021)

(theresistornetwork.com)

26 points | by austinallegro 8 hours ago ago

14 comments

  • the-golden-one 5 hours ago

    Dolby have been doing this for years for audio on cinema film reels - literally from tiny QR-like codes between the sprocket holes on the filmstrip, with cinema-grade audio quality.

  • TazeTSchnitzel 7 hours ago

    In a sense this is reinventing digital sound-on-film, but without the continuous feed and with a much lower tape speed. https://en.wikipedia.org/wiki/Sound-on-film

  • kardianos 3 hours ago

    Cool project.

    Though if you are looking at QR codes for something like this (internal, on paper), strongly consider using data matrix codes. They are more compact, same available error correction codes, and actually have a composition story rather then spaces between them.

    Do to how datamatrix codes can be composed, you could probably design a code that both fills the height and does a continuous stream of codes with no horizontal white space between them, just a solid bar as per the spec.

  • Paianni 2 hours ago

    I was thinking, in a world without DRAM, cobalt-infused magnetic tape (like that used for VHS and ferricobalt cassettes) or metal particle tape, digital sound recording would still be possible using 1960s black-and-white VTRs that took ferric oxide tape not dissimilar to those used for analog multitrack recording.

    • burnt-resistor an hour ago

      In terms of physical media:

      For 1/8" cassette tape, KCS appeared in 1975 but the tape itself was in use 20+ years prior: https://en.wikipedia.org/wiki/Kansas_City_standard

      ½" consumer tape of Betamax and VHS didn't arrive until the same year.

      ¼" QIC DC300 appeared ~1972 but was largely inaccessible to hobbyists and home users until around 1995/1996 with QIC-40 and Travan.

      There were also home 1/4" reel-to-reel home audio systems from roughly mid '50's onward.

  • xnx 4 hours ago
  • enjoykaz 8 hours ago

    The compression choice is what makes this work. OPUS at 12 kbps is good enough to not embarrass itself — ten years ago you'd have needed a much faster tape speed to get acceptable audio. The paper tape is the aesthetic, the codec is doing the real work.

  • kristopolous 6 hours ago

    Really like it. For some reason I'd insist on spectrograph instead of qr - artifacts make the medium. The fragile bizarre distortions and loss of the double digitization of analog data - you'd end up with more of an instrument than a format.

    Think along these lines https://youtu.be/Z7Zb4rso82M?si=3FYaidCwwVdUhocO

    Imagine being able to control where the loss happened in real time with potentiometers

  • resters 4 hours ago

    Has anyone yet made an app that lets you wave your phone around a vinyl record and capture macro video and then play the music through the phone's speaker?

    • gwbas1c 3 hours ago

      Years ago I read an article on Slashdot where someone did that with a flatbed scanner. (This was before everyone had a smartphone, and before digital cameras were common.)

      Audio quality was poor.

  • burnt-resistor 2 hours ago

    This is rad. I love that it's built out of cardboard, but would've accepted LEGO, Tinkertoy (Classic), or Erector Set.

    Fantasound was pretty impressive for optical multichannel sound:

    https://www.r-type.org/articles/art-299.htm