METHOD AND APPARATUS FOR RECOVERING A STANDARD TELEVISION SIGNAL FROM A MODIFIED SIGNAL

摘要

A standard television signal is recovered from one which has been modified to inhibit unauthorized recording/reproduction by changing the number of horizontal line intervals which constitute a frame, according to predetermined profile patterns. Recovery is accomplished by digitizing each field of the modified signal, writing the field into memory, reading a field with a standard number of lines from memory and converting it to analog form. Recovery of the standard number of horizontal lines can be performed while writing the field into memory, while reading the field out of memory or while the field is in memory. WP7:2040.APP