How to schedule VLC recording with cron?
You're using the rc (remote control) interface, which expects input on the command line - i.e., expects and interactive session.

From cron try the dummy interface: 

0/5 * * * * /Applications/VLC.app/Contents/MacOS/VLC -I dummy rtp://@xxx.xxx.xxx.xxx:5050 --sout='#transcode{vcodec=h264,vb=2048,acodec=mp3,ab=192,deinterlace}:standard{mux=ts,access=file{no-overwrite},dst=/Users/me/Pictures/video.ts}' --run-time=10 --play-and-exit &gt;&gt; /tmp/log.txt 2&gt;&amp;1