IP Cam Simulation

Hi, I have several IP cam that support RTSP, recording to micro SD card, motion detection and online live view. However the SD card has limited storage and the live view function seems transmitted without encryption. The cam is running linux and sadly the manufacturer never release the GPL source code. I am not sure if all those functions can be simulated on my openwrt-powered router/AP.

Goal

  • recording all videos to my USB harddisk
    should be quite easy with ffmpeg and directly copying the stream. Currently I can run 4 instances of ffmpeg for my 4 cameras, not sure if it can be done with single instance of ffmpeg
  • broadcast the stream so I can connect to my ISP's IP and view the stream with authentication , without using third party redirect/streaming service
    not sure since ffserver has been discontined and I have no experience in this area
  • create screenshot if motion detected
    Not sure if it can be done with ffmpeg

Any comments are welcome

Any status on your project?
I'm thinking of getting an ASUS RT-AX53U (4 core, MediaTek MT7621AT) + a USB HDD (only USB 2.0).
One or two IP cams saving video to the OpenWRT box. Would this work? How about playback?
Can ffmpeg do the job?