Methods, systems, circuits, devices, and apparatuses are described for auto-detection and adaptive configuration of high-definition multimedia interface (HDMI) ports. Unique systems and circuits allow HDMI repeaters to automatically detect if an HDMI device that has been connected thereto, via an HDMI port, is an HDMI source (source mode) or an HDMI sink (sink mode). The unique systems and circuits may be adaptively configured to allow the HDMI port to function as an HDMI input or an HDMI output based on the automatic detection. Methods corresponding to the functions performed by the systems and apparatuses are provided, and computer readable storage media with computer program instructions encoded thereon for enabling processing devices to perform the methods are also provided.