I wanted to tie my security system with 4 wired cameras to my 2 IP cameras, 2 Android tablets, 1 android phone, and a webcam together as a unified security system. Zoneminder 1.28.1 runs all of them without using FFMPEG.
It works with the Winbook DVR security system using the following settings:
Source Type: Libvlc
Source path: rtsp://(your DVR's url):554/H264?subtype=0&ch=1
(Subtype 0 = Hi Def, 1=Low Def)
(ch=1 channel 1, ch=2 channel 2, etc.)
Remote method: RTP/RTSP
W/H: 720/480
Hope this helps someone.