Get a Raspberry Pi, or one of the very cheap clones. Then install FFMpeg and an RTMP server with RTSP capability (EvoStream, Wowza).
Make sure the RTMP server is operational.
Ask FFMpeg to convert from MxPEG to H.264 and broadcast to the RTMP server, by entering this command (on one line)
ffmpeg -f mxg -i http://[user]:[pass]@[camera-host]/cgi-bin/faststream.jpg?stream=mxpeg -codec:v libx264 -b:v 500k -maxrate 500k -bufsize 1000k -vf scale=-1:480 -threads 0 -an -f flv [rtmp address]
If you are using EvoStream, you might have entered something like this for the RTMP address:
rtmp://[ip of evostream]/live/mobotix
If that is the case, you can add a generic RTSP camera to your VMS
rtsp://[ip of evostream]/mobotix
The MxPEG stream will now be converted to H.264 and recorded as such. You’ll miss out on the advantages of MxPEG, but sometimes there’s no other way around the issue.