Decode IP Cameras To BNC For Matrix Integration?

bump.. no feedback?

There are decoders that have BNC/Composite out, but to accomplish your goal, you would need one per channel.  You are looking at around $200 per channel MINIMUM with the products I am aware of.  There might be something less expensive that I haven't run across.  

Sure they do not have analog out of the cameras? Most of the more main stream devices accommodate a local analog output. Only issue have to have multiple cables to eac unit  

While it is possible theoretically, it is not a simple process - an analog signal must be created from digital frames, and I fail to see why would anyone ever want to convert digital HD video to analog. 

Besides, HD matrix is even a thing? I thought matrixes pretty much died out when $300 computers became powerful enough to display 16 streaming channels

IMO, even if you find a solution it would be more expensive than a new video wall.

We are faced with this dilemma in jails.  They typically have door control systems which integrate with a matrix switch (requests come in, on the PLC display they click a door and the camera pops up on the display monitor).  We found that HD analog cameras would not work through the BW ability of the matrix and decoding was slow.  It was better to either display all camera on a large screen (IP based) or encode the cameras, use a serial IP interface to acquire the ASCII commands via RS-232/485, and program events and virtual matrix on an IP based VMS based on these events (for example, door control system sends out "cam05 mon01" via ASCII -VMS monitors via serial IP device and switches pane to cam05 when input recieved).  

The axis P7701 would do what you want.

You would need to add an adapter from the rca output to connect to a BNC patch cable.