Storage of digitized video images on disk

摘要

Digital pixel values for each image frame are written onto pages of a disk buffer memory (DBM) under video frame timing and are read from memory and written on disk under disk timing. When the last page of the DBM is reached, readout is switched back to the first page. Only DBM locations for pixels within the circular boundaries of the image are addressed during reading and writing. Groups of adjacent pixels are written simultaneously on the several disks under control of clocks that are derived from disk. A circuit corrects for skew resulting from asynchronism between the disks. A converter converts serially recorded pixels of any bit length to parallel bits of the same number as before they were serialized. The commands for the disk drive are put in registers for one disk index pulse and they are ready for execution when the next index pulse occurs.