Is there a way to send a video signal into an Android device?
TrinusVR is an app that allows you to stream HD video from you PC to your smartphone, either wireless with some latency, or with a USB cord without latency. Meant for video games but it will stream whatever is on your computer screen. Then you need an HDMI capture device connected to your PC, and you've got a way to port HDMI into your Android. The catch is that it split screens the image for use in VR goggles, but I believe you can bypass that.