15 Sep CCTV Articles What is a Substream? October 28, 2011 Posted by Security Camera King CCTV, dual stream, h.264 dvr, security dvr, substream Leave a comment Some of the newer DVRs on the market offer a feature called either a substream or a dual stream. A sub stream is used for viewing your DVR over the LAN or WAN when...Read more Facebook Twitter Email Pinterest LinkedIn