This is a hardware question about HDMI port

I have serveral Macbook Pros and a Mac mini. These have HDMI ports.

On the Mac mini I and using its HDMI port to connect to a Samsung

monitor/tv.

The question is:

Is the HDMI port only for out? Or can it be used to pipe signal from

an external camera to an app like iMovie?

My concern is how to get video signal from Canon video camcorder to

computer and to to video app. On this camera the options appear to be

HDMI or A/V out. It does have a USB port but documentation does not specify

that it can be used to connect to a computer. The documentation only

has USB port on camera for an external GPS unit.

But I don't want to plug an HDMI cable into the Macbook or mini if its HDMI port

is only for sending and not receiving signals.

Can anyone with experience with this give me some guidance?

Thank you

JK