Video Saving Device Cops Use

This kind of HDMI capture device is aimed at retaining high video quality for broadcast video using Apple ProRes or Avid DNxHR codecs. These lossless codecs generate very large files compared to what is usually used for video surveillance, i.e. the lossy H.264 codec. Accordingly this device is not likely a best fit for Kenny Johnson's purposes.

Unless you wanted to edit the video footage, I would suggest using another device that supports the H.264 or H.265 codec. John Scanlan's reference to the Elgato HD60 looks very good as it supports H.264.

One warning about capturing the output of NVR's is to test this is possible before committing to purchase. This is because the output of some HDMI devices may have copy protection permanently enabled which means you won't be able to capture the output even though you will be able to view it on a HDMI monitor or TV. When HDMI was a new technology, video manufacturers enabled copy protection on the HDMI output of their devices by default because they hadn't considered a scenario where it would be useful to leave it disabled. It was mostly after manufacturers of uncompressed video capture cards lobbied for this to change that capture from HDMI outputs became possible. That is why you should find that DVD and Blu-ray players shouldn't allow you to capture their HDMI output when playing copy-protected movies but you should now be able to capture the HDMI output from video cameras and smartphones.