The random access memory provides {HEAD ~ realtime access} for recording and playing back {TAIL ~ video} from and to a video source 
for playing back
The random access memory provides { HEAD ~ realtime access } for recording and playing back { TAIL ~ video } from and to a video source
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH