Television system for recovering digital data encoded in a television signal

摘要

A television system for recovering the digital data encoded in a television signal at an encoding frequency. The television signal is sampled at a frequency much higher than the encoding frequency, and the resulting sampled data elements are stored in a memory. Sampled data elements corresponding to a clock run-in portion (synchronization signal portion) of the television signal are examined to a samples interval equal to the number of samples per encoding clock periods. Transitions in the values of data elements are determined by examining consecutive sampled data elements. In general, sampled data elements are selected with an interval equal to the determined samples interval as representing the encoded digital data elements. However, the selection sequence is adjusted according to the transitions to ensure that the samples in only the stable portions of the television signal are selected.