The position designator 110 determines the displayed position of the child frame video in {HEAD ~ accordance} with displayable time information of the child frame video and {TAIL ~ information} on the displayed area or displayable area depending on time, included in the data for display 
The position designator 110 determines the displayed position of the child frame video in { HEAD ~ accordance } with displayable time information of the child frame video and { TAIL ~ information } on the displayed area or displayable area depending on time , included in the data for display
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH