Patent ID: 7289721

Claim:
An apparatus for playing back data stored on an information recording medium, the data having audio information, visual information, or audio-visual information, the data containing a watermark, the apparatus comprising: a reproduction processing circuit configured to receive the information that is stored on the information recording medium to produce the data; and playback circuitry comprising: a data store; a data selection circuit configured to select a subset of the data which is necessary for the detection of the watermark and to store the subset of the data into the data store; a detecting circuit coupled to the data store and configured to process data contained therein to produce a detection result, the detection result being based on the watermark; and a control circuit configured to selectively output the data based on the detection result, wherein the data selection circuit and the detecting circuit operate in alternating fashion to alternate between storing a subset of the data to the data store and reading out the subset of the data for watermark detection.