Patent ID: 8797459

Claim:
A method of transmitting a digital broadcast signal, the method comprising: multiplexing video data, audio data, and supplementary data into MPEG2 transport stream, the supplementary data including an event information table (EIT) and a program map table (PMT), wherein the EIT or the PMT includes a caption service descriptor, wherein the caption service descriptor includes caption information indicating whether a digital television closed caption service is present in the video data or a line 21 closed caption service is present in the video data in accordance with electronic industry association (EIA) 708, wherein the caption service descriptor further includes information indicating the closed caption service is formatted for displays with 16:9 aspect ratio, wherein the caption service descriptor further includes a caption service number field, the caption service number field identifying a caption service number of each of the closed caption services, and wherein the caption service number field is defined only when the digital television closed caption service in accordance with electronic industry association (EIA) 708 is present; and transmitting the digital broadcast signal.