Use iMac to display Hdmi output from a device

I would like to use iMac with thunder bolt port to view Hdmi output from a settop tv box (iptv)

I have not tried as of yet, but hoping I can just buy a hdmi to thunderbolt cable and put iMac in display mode to view tv box output? however on web search i keep seeing the use of and adapter box between output source and Mac, is this required?

最后更新：2017-09-04 21:06:20