A multichannel display data generating apparatus for generating data for displaying AV data on a multiscreen has a plurality of screens for displaying AV data of a plurality of channels, said apparatus comprising: input means for inputting AV data of a plurality of channels being transferred using a transport packet of a transport stream; a smaller number of PCR extracting means for extracting in a time-sharing mode the PCR of a plurality of channels displayed on said plurality of screens than the number of said plurality of screens; the same number of PLL means for establishing PLL synchronization by using said extracted PCR as the number of said plurality of screens; the same number of STC (system time clock) counter means for counting the times of the channels displayed on said plurality of screens by using the oscillation frequency of said PLL means as the number of said plurality of screens; AV decoding means for AV-decoding the AV data of the channels displayed on said multiscreen in AV synchronization with said STC counter means; and output means for outputting said AV-decoded AV data; and wherein said output AV data is displayed on said multiscreen.