3 ms·

If anyone else went "wait, WTF? Surely it can't be..." on reading that post: I checked, and yes, it can. Wikipedia: > Although similar in appearance to compac

If anyone else went "wait, WTF? Surely it can't be..." on reading that post: I checked, and yes, it can. Wikipedia: > Although similar in appearance to compact discs or DVDs, early LaserDiscs used analog video stored in the composite domain (having a video bandwidth and resolution approximately equivalent to the 1-inch (25 mm) Type C videotape format) with analog FM stereo sound and PCM digital audio. Later discs used D-2 instead of Type C videotape for mastering. The LaserDisc at its most fundamental level was still recorded as a series of pits and lands much like CDs, DVDs, and even Blu-ray Discs are today. In true digital media the pits, or their edges, directly represent 1s and 0s of a binary digital information stream. On a LaserDisc, the information is encoded as analog frequency modulation and is contained in the lengths and spacing of the pits.

schmichael 5y ago
I absolutely thought it was a joke! Thanks for the context! Any clue it’s possible to read vinyl records this way or are the grooves/material too ill suited for lasers to easily read? Reading deformities of grooves seems like it would require orders of magnitude more precision than the length and spacing of pits, but I know nothing about the physics and hardware here.
- brimble 5y ago
  Contact-free laser record players exist and have for quite a while, yeah. Main benefit AFAI can tell is avoiding wear on the vinyl.
  - unkoman 5y ago
    None are sold to the common consumer or even usable if you had the money [1]. Vinyl wear by using a needle is overstated anyway [2]. [1]: https://youtu.be/2oeTqAogMvA?t=248 https://youtu.be/2oeTqAogMvA?t=248 [2]: https://www.youtube.com/watch?v=xf_cPU8gtd8 https://www.youtube.com/watch?v=xf_cPU8gtd8
- smitty1110 5y ago
  ELP Japan has you covered! https://www.elpj.com/ https://www.elpj.com/ Last time I looked into this, I heard it was good if you had a REALLY good record cleaner. It’s extremely sensitive to dust in the groove.
chungy 5y ago
I sort of assumed that Hacker News types would have already known that video on LaserDisc is analog. :) Audio is somewhat more complicated; the original standards had that as analog too, but digital options were introduced (I'd like to say early 1980s, but not entirely sure).
- chiph 5y ago
  The first digital audio laserdiscs I bought were in/around 1986. They used AC-3 encoding (later known as Dolby Digital 5.1) but were recorded as an RF signal onto the discs, because the format was analog. You needed a decoder to turn it into discrete channels, which a few receivers had. But most often you would get an external box, like the Yamaha DDP-1

schmichael 5y ago

I absolutely thought it was a joke! Thanks for the context! Any clue it’s possible to read vinyl records this way or are the grooves/material too ill suited for lasers to easily read? Reading deformities of grooves seems like it would require orders of magnitude more precision than the length and spacing of pits, but I know nothing about the physics and hardware here.

brimble 5y ago
Contact-free laser record players exist and have for quite a while, yeah. Main benefit AFAI can tell is avoiding wear on the vinyl.
- unkoman 5y ago
  None are sold to the common consumer or even usable if you had the money [1]. Vinyl wear by using a needle is overstated anyway [2]. [1]: https://youtu.be/2oeTqAogMvA?t=248 https://youtu.be/2oeTqAogMvA?t=248 [2]: https://www.youtube.com/watch?v=xf_cPU8gtd8 https://www.youtube.com/watch?v=xf_cPU8gtd8
smitty1110 5y ago
ELP Japan has you covered! https://www.elpj.com/ https://www.elpj.com/ Last time I looked into this, I heard it was good if you had a REALLY good record cleaner. It’s extremely sensitive to dust in the groove.

chungy 5y ago

I sort of assumed that Hacker News types would have already known that video on LaserDisc is analog. :) Audio is somewhat more complicated; the original standards had that as analog too, but digital options were introduced (I'd like to say early 1980s, but not entirely sure).

chiph 5y ago
The first digital audio laserdiscs I bought were in/around 1986. They used AC-3 encoding (later known as Dolby Digital 5.1) but were recorded as an RF signal onto the discs, because the format was analog. You needed a decoder to turn it into discrete channels, which a few receivers had. But most often you would get an external box, like the Yamaha DDP-1