| 摘要 |
A decoder of a digital television signal includes apparatus for synchronizing changes in the format of the digital television signal to corresponding changes in the format of an on-screen display. The apparatus includes a video decoder that receives the digital television signal, determines the format of the digital television signal and whether this format represents a format change. When the decoder identifies a format change, it generates an output signal indicating the format change and assigns a unique identifier to the format change. This output signal is sent to an on-screen display processor and to a user interface processor. The user interface processor is coupled to the video decoder and to the on-screen display processor to receive the output signal and to generate commands for the on-screen display processor. With one of these commands, the user interface sends the unique identifier received from the decoder to the on-screen display processor. The on-screen display processor is disabled by the decoder when a format change is identified. The on-screen display processor monitors the identifiers received from the decoder and from the user interface and enables the display of on-screen display messages only when the two identifiers are the same. <IMAGE> |
