We are digital librarians. Among us are represented the various reasons to keep data -- legal requirements, competitive requirements, uncertainty of permanence of cloud services, distaste for transmitting your data externally (e.g. government or corporate espionage), cultural and familial archivists, internet collapse preppers, and people who do it themselves so they're sure it's done right. Everyone has their reasons for curating the data they have decided to keep (either forever or For A Damn Long Time (tm) ). Along the way we have sought out like-minded individuals to exchange strategies, war stories, and cautionary tales of failures.
Been around in usable form since 2017. Though the hardware and and software has been highly refined. https://www.domesday86.com/
An offshoot, RF Decode for VHS has been in development since 2019 and has also progressed nicely. Though still not an off the shelf project. https://forum.videohelp.com/threads/394168-Current-status-of-ld-decode-vhs-decode-%28true-backup-of-RF-signals%29
Fantastic Video. I watched it this morning. I Kinda want to know more now about the analog signal specifications on the laser disc. I thought it was digital as a youth. I had no idea that it was analog-ish.
The video is completely analog. Digital audio was added later.
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. A carrier frequency is modulated by the baseband video signal (and analog soundtracks). In a simplified view, positive parts of this variable frequency signal can produce lands and negative parts can be pits, which results in a projection of the FM signal along the track on the disc. When reading, the FM carrier can be reconstructed from the succession of pit edges, and demodulated to extract the original video signal (in practice, selection between pit and land parts uses intersection of the FM carrier with a horizontal line having an offset from the zero axis, for noise considerations). If PCM sound is present, its waveform, considered as an analog signal, can be added to the FM carrier, which modulates the width of the intersection with the horizontal threshold. As a result, space between pit centers essentially represent video (as frequency), and pits' lengths code for PCM sound information.[22] Early LaserDiscs featured in 1978 were entirely analog but the format evolved to incorporate digital stereo sound in CD format (sometimes with a TOSlink or coax output to feed an external digital-to-analog converter or DAC), and later multi-channel formats such as Dolby Digital and DTS.
The analog video on laserdiscs is encoded as PWM which is on-off like digital, not analog grooves like a phonograph record.