| 摘要 |
<p>An auxiliary digital data extractor in a television receiver includes a source of a composite video signal. The composite video signal includes an auxiliary digital data component which is either a first frame code having a predetermined number of bits and auxiliary data in a first format, or a second frame code having the same number of bits and auxiliary data in a second format. A frame code detector is coupled to the composite video signal source. The frame code detector is responsive to one subset of the frame code bits to detect the first frame code and to a different subset of frame code bits to detect the second frame code. An auxiliary data utilization circuit is coupled to the composite video signal source and the frame code detector. The auxiliary data utilization circuit receives auxiliary data in the either first format when the first frame code is detected or the second format when the second frame code is detected.</p> |
