Abstract: Indicated as hybrid D-PCM a new transmission system is given which is based on differential pulse code modulation (DPCM) with signal compression at the transmitter end and signal expansion at the receiver end.In the transmitter defined auxiliary information is fed to the DPCM code groups to obtain composite code groups, while in the receiver a local auxiliary signal derived from a reconstruction device is subtracted in a separating device from the received composite signal. With a particularly simple construction hybrid D-PCM is distinguished as compared with DPCM by effective perturbation reduction, in addition to which a pulse can be saved in the transmitted code groups.

Abstract: When the information of a continuous-motion video record is displayed in the stop-motion mode by repeated display of two fields which form an interlaced picture, motion in the scene gives rise to a frame-frequency flicker phenomenon in the stop-motion picture. By forming suitable video signal combinations in discrete groups which each comprise two associated fields and by recording these combinations in the video record, the flicker phenomenon in a stop-motion picture is eliminated without continuous display being perceptibly affected.