I've been collecting LaserDiscs for years and always been keeping an eye out for the best way to preserve them. The Domesday Duplicator has been on my radar ...
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.
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.
https://en.wikipedia.org/wiki/LaserDisc