The present application discloses a signal source detection and selection system for detecting and selecting a signal source for a display apparatus having a plurality of signal input interfaces configured to receive a plurality of input signals from a plurality of signal sources. The signal source detection and selection system includes an input interface scanner, an interface selector, a signal processor, and an output terminal. The input interface scanner is configured to scan each of the plurality of signal input interfaces and determine whether at least one signal input interfaces receives input signals. The interface selector, coupled to the input interface detector, is configured to select a signal input interface as a selected signal input interface, and gate an input signal from the selected signal input interface to the signal processor. The signal processor, coupled to the input interface selector, is configured to process the input signal from the selected signal input interface to generate a processed signal. The output terminal is configured to output the processed signal.