more detail below video protection switch vps 30 receives video signals 40 and 41 from the two transmission paths 12 1 and 12 2 respectively and produces a video output signal 45 from one of the two input video signals 40 or 41 in addition vps 30 receives alarm signals from alarm relay outputs 35 and 36 at decoders 25 and 26 respectively alarm relay output 35 sends an alarm signal to vps 30 upon a detection of a video signal error or failure in transmission path 12 1 e g errors introduced by encoder 15 transmission channel 20 1 or decoder 25 and alarm relay output 36 sends an alarm signal to vps 30 upon a detection of a video signal error or failure in transmission path 12 2 such error or alarm signals are provided in conventional decoders such as the previously mentioned digilink 1220 encoder decoder as discussed below in the event of a video signal error or failure on one of transmission paths 12 1 12 2 vps 30 switches from the failing transmission path to the back up or other transmission path fig3 illustrates a video transmission system 13 having a plurality of video sources 10 each of which transmits video signals over two transmission paths in a manner similar to that in transmission system 5 in fig2 thus in accordance with the embodiment illustrated in fig3 the first transmission path for the video signal from video.