Video processing circuit with line memory control

摘要

PCT No. PCT/US91/03810 Sec. 371 Date Nov. 12, 1992 Sec. 102(e) Date Nov. 12, 1992 PCT Filed May 30, 1991.A line memory and control system comprises a line memory, for example a first in first out (FIFO) device. A comparator compares a first value, specifying a location in the horizontal line period where reading or writing of the line memory is to begin, with a second value, fixing pixel location within each line period. A register stores the number of data samples stored in the line memory. A counter counts the number of data samples which have actually been written into the line memory or read from the line memory. The counter has an output of the comparator as a first input and the number of data samples previously stored in the line memory as a second input. In the case of both compression and expansion, a line memory control system assures that the number of samples written into each FIFO line memory be the same as the number of samples read out of each FIFO line memory.