SYSTEME VIDEO COMBINE AVEC DES CANAUX DE SON MULTIPLES

摘要

A number of sound channels are each applied to sampling and data storage circuits. Each of these circuits receives two clock signals, one of which is a square wave synchronised with the horizontal sync. pulses of the video signal. The second clock signal is at twice the frequency of the first and the sound signals are sampled at the trailing edge of this clock pulse. A sampling signal pulse identifies the sampling interval and a start conversion signal triggers an A/D converter in the sampling circuit. The digital data is stored in a memory ready for transfer to a main memory. During the vertical line return period, the compressed sound signals are read sequentially and are transmitted during the unused line period by combination in a logic circuit with the video signal.