In a data recording and reproducing apparatus which records and reproduces a record medium in which at least two kinds of data having different data types can be recorded, data are read out from the record medium, and a digital watermark is detected from the data read out. The kind of data is determined...http://www.google.com/patents/US6278807?utm_source=gb-gplus-sharePatent US6278807 - Data recording/reproducing apparatus, data recording/reproducing method applied to the apparatus, and computer program product used in data processing apparatus
