Analog or serial digital video input with automatic video switch

An instrument has a single video input port for receiving either analog or serial digital video signals coupled to both an analog and a serial digital video input path. The outputs of the analog and serial digital video input paths are provided as respective inputs to a video switch, the output of which is then provided to the instrument for further processing. Information from the serial digital video input path, which may include clock recovery lock, carrier detect and/or video standard, is provided to a decision module that generates a select signal for the video switch. As an example, if "lock" is present, then the output from the serial digital video input path is selected automatically for output by the video switch, otherwise the output from the analog video input path is selected automatically. The automatic selection for the switch may be manually overridden. A text display is provided to indicate which video input path the instrument is processing according to the output from the video switch, as well as information about the video signal at the video input port.