Key signal producing apparatus for video picture composition

摘要: First and second memories are provided for receiving key signals which control a display to output video composition made up of plurality signals. The received from signal generator in synchronism with the speed generator. first memory receives directly, while gated storing related to, example, still image, gating is controlled so that only overwritten when it expressly intended do so. A read address controls reading out both memories, apparatus displays images. further gate may be input into memory, this being by state coming memory. Another aspect invention relates system comprising receiving, storing, outputting signals, respectively. selector selecting one selected stored outputted as signal. priority order setting selects outputs according order. select