Quote:
Originally Posted by ChrisW6ATV
A clear freeze frame does not explicitly require digital memory at all. Sony did it in 1981 with their SL-5800, using dual-azimuth video heads.
Pioneer sold its first Laser Disc player with digital video memory in 1988-89, the CLD-3030. That machine only stored one field of NTSC video, so that is an indication of the cost of memory at that time.
It also may be that just storing frames/fields of video is a lot simpler than actually manipulating that memory as needed for time-base correction. That level of information is beyond my knowledge.
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Of course on half the Laser discs made that player didn't need it's frame store. On CAV (constant angular velocity) discs where disc speed was constant and one rotation= one frame older LD players would simply skip the laser back one track on IIRC the vertical sync interval of the frame, effectively playing the same frame over and over the way many lower end VCRs do. On later CLV (constant linear velocity) discs where the disc speed changed depending on how far from the center you were reading and the sync pulses of adjacent frames were NOT in the same rotational location on the disc, a frame store was necessary for stills since on CLV there was no effective way to move the laser instantly from the end sync pulses of a frame to the beginning sync pulses of the same frame.