A system for composition/decomposition of video signals to enable to transmit/receive and to record/playback contemporaneously two tv programs

摘要

Subject-matter of this invention is a system for composition/decomposition of video signals for transmitting/receiving and for recording/reproducing with alternance of fields two different television programs, wherein, in a transmission/recording operation, the two video signals (V1, V2) of the two different programs are composed by means of a composer device (8; SW) into a single composite video resulting signal [V1 + V2] which includes a field (odd or even rows) of the first signal (V1) and a field (even or odd rows) of the second signal (V2) and, in a reception/reproduction operation, each frame of said video resultant signal [V1 + V2] is decomposed by means of a decomposer device (108; M1, M2) into its component fields (odd and even rows), respectively pertaining the one to said first video signal (V1) and the second to said second video signal (V2), said signals being adapted to be separately utilised after having been passed through a duplicator device (114; A/D-MEM-D/A) which adds to each field obtained by means of said decomposition step an identical field obtained by duplication thereof, in order to re-establish a whole frame.