FIX C GSTREAMER ubuntu/raspberry mosaic rtsp

I need a robust C application that displays a mosaic of 4 RTSP video streams in a single window. The program should immediately open the window with the mosaic layout, begin connecting to the RTSP streams, and every 60 seconds check if each stream is active—reconnecting any inactive streams. The final source code must compile and run reliably on both Ubuntu x64 and Raspberry Pi.