Flole
It should be here -> "Input #0, [here] rtp...", but it is not.
In tvheadend with pass it generates a .ts and because this work means its MPEG iI think:
ffmpeg -protocol_whitelist file,udp,rtp -i rtp://@xxx.xx.xx.xx:xxxx -c copy -f mpegts -t 10 output.ts