A method and apparatus for decoding data encoded in the horizontal overscan portion of a video signal. A video data detector is configured to decode data encoded in a video signal in a first type of video signal format, such as NTSC. When the detector receives the video signal, it enters a “fast acquisition” loop in which it attempts to decode a sequence of valid data from several consecutive frames of the video signal. If the detector cannot decode a sequence of valid data from the consecutive frames of the video signal, the detector is reconfigured to decode data encoded in the video signal in a second type of video signal format, such as PAL. The detector then attempts to decode a sequence of valid data from the next several consecutive frames of the video signal. If the detector is unable to decode a sequence of valid data from the consecutive frames, the detector is reconfigured for the first type of video signal format and the above process repeats. If the detector decodes a sequence of valid data in the several consecutive frames of the video signal, the detector enters a “controlled persistence” loop. In the controlled persistence loop, the detector continues to decode data until it fails to decode valid data from a series of consecutive video frames. When the detector fails to decode data from a series of consecutive video frames, the detector reenters the fast acquisition loop.