As a result, the child frame video can be switched freely between display and non display within {HEAD ~ the range} of {TAIL ~ the displayable time} 
of
As a result , the child frame video can be switched freely between display and non display within { HEAD ~ the range } of { TAIL ~ the displayable time }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL