Use ffmpeg to stream over UDP to a remote endpoint:

ffmpeg -i input -f format udp://hostname:port

Use ffmpeg to stream in mpegts format over UDP using 188 sized UDP packets, using a large input buffer:

ffmpeg -i input -f mpegts udp://hostname:port?pkt_size=188&buffer_size=65535

Use ffmpeg to receive over UDP from a remote endpoint:

ffmpeg -i udp://[multicast-address]:port ...