The Flex 4K HDMI In to Full NDI Encoder from BirdDog is an ultracompact NDI interface for HDMI video sources. Connect your onboard monitor, camera, or other video source, and have it be instantly available on your NDI-enabled network. The BirdDog Flex In supports up to UHD 4K30 and 1080p60 resolution video.
 
https://www.bhphotovideo.com/c/product/1574848-REG/birddog_bdflexenc_flex_4k_full_ndi.html/overview?sts=pi&pim=Y