My TV has only one HDMI input which my Contour box is connected to. My last cable box had an HDMI input so that I could use my video player. All of it was mounted on a shelf that is hard to access. W...
Unless you purchase a third device as an HDMI switcher, your best bet is the use the other connectors on your TV. For example, if both your TV and cable box have component connectors, you could free the HDMI for your video player. Although your video player may have component connections, some protected-movies will be limited to 1080i via component.
Different markets (regions) have different cable boxes. You'd have to research which boxes in your market support HDMI-In. Go to the following link, enter your Zip and research only the boxes you need, such as with or without DVR service:
if you don't want to research, call your Cox Store for your needs.
Manufacturers (Cisco, Scientific Atlanta, Arris) make the same box for various providers (Cox, Verizon, Comcast). The provider determines if HDMI-In will be active or not. If yours is inactive, it'll stay inactive.