Hints for usage:
play without delay
ffplay -fflags nobuffer /dev/video1

# works for network streams, not for /dev/video
ffplay -probesize 32 -sync ext http://192.168.3.248/VIDEO.CGI

ffplay -fflags nobuffer -flags low_delay -framedrop \
 -strict experimental -rtsp_transport tcp rtsp://<host>:<port>