Patent ID: 8769562

Claim:
A digital broadcast method comprising: acquiring, by a data transmitting device, audio data and video data that form a predetermined content for digital broadcasting, and related data indicating a content related to the predetermined content; performing, by the data transmitting device, a control that transmits the acquired related data to a data receiving device prior to transmitting the acquired audio data and the acquired video data; storing, by the data receiving device, an identifier of a first channel selected by a viewer in a channel storage; receiving, by the data receiving device, the audio data and the video data that form the predetermined content corresponding to the first channel and the related data of the predetermined content that have been subject to the control; storing, by the data receiving device, the received related data in a data storage; changing, by the data receiving device, a viewing channel by receiving a changing instruction of the viewing channel from the viewer; deleting, by the data receiving device, the related data stored in the data storage and replacing the identifier of the first channel stored in the channel storage by an identifier of the currently selected channel when the viewing channel is not changed before a predetermined time has passed since the viewing channel is changed at the changing; determining, by the data receiving device, when the viewing channel is further changed before the predetermined time has passed since the viewing channel is changed at the changing, whether the lastly selected channel is identical to the first channel by comparing an identifier of the lastly selected channel and the identifier stored in the channel storage; and outputting, by the data receiving device, when the lastly selected channel is identical to the first channel, the related data stored in the data storage with audio data and video data corresponding to the lastly selected channel to an output unit.