Patent ID: 6043848
Filing Date: 2000-03-28
Classification: H04N

Abstract:
A method of recovering a plurality of digital data elements encoded in a television signal according to a predetermined format, wherein said plurality of digital data elements are encoded in said television signal at an encoding frequency, wherein said television signal includes a synchronization portion having transitions encoded at said encoding frequency, said television signal further including a data portion including said digital data elements encoded at said encoding frequency, said method comprising the steps of:(a) sampling said television signal at a sampling frequency to generate a sequence of sampled data elements, wherein said sampling frequency is higher than said encoding frequency;(b) storing said sequence of sampled data elements in a memory;(c) examining said sequence of sampled data elements to determine a number of samples representing said synchronization portion;(d) determining a samples interval by dividing said number of samples with a number of transitions in said synchronization portion, wherein said samples interval represents an average number of samples per a clock period corresponding to said encoding frequency;(e) examining consecutive sampled data elements representing said data portion to determine whether a transition exists in the data values of successive sampled data elements;(f) forming a plurality of selected data elements by selecting data elements from said sequence of sampled data elements of said data portion generally with an interval equal to said samples interval, but adjusting the selection according to said determination in step (e) to ensure that data elements sampled in stable portions of said television signal are selected, wherein said stable portions are present after the completion of said transitions determined in step (e) and wherein said plurality of selected data elements represent said plurality of digital data elements encoded in said television signal.