steps for setting up a test rtsp source:  

1. download rtsp-simple-server from here and extract the archive
2. download rtsp-simple-server.yml file from here
3. either set protocols value to udp or tcp in the yml file
4. turn off rtmp, hls in the yml file
5. create an mp4 file to stream from:  

   $ ffmpeg -f lavfi -i testsrc -t 30 -pix_fmt yuv420p test.mp4
   

6. run:  

   $ ./rtsp-simple-server rtsp-simple-server.yml 
   $ ffmpeg -re -stream_loop -1 -i test.mp4 -f \
     rtsp -rtsp_transport tcp rtsp://localhost:8554/live_stream
   

7. play rtsp://localhost:8554/live_stream in vlc