Patent ID: 6993133

Claim:
A data recording and reproduction apparatus into which a first audio data stream which has been subjected to a data conversion process for digital audio data and a second audio data stream which has not been subjected to the data conversion process for digital audio data are inputted, and which records and reproduces each inputted audio data stream, wherein the data conversion process causes the first audio data stream to become a stream which is unsuitable for watermark insertion, said apparatus comprising: a stream storage unit for storing each of the first and second audio data streams; a stream writing unit for writing each of the first and second audio data streams into said stream storage unit; and a stream reading unit for reading each audio data stream from said stream storage unit, for inserting a watermark into each read audio data stream, and for outputting a watermark-inserted audio data stream for each read audio data stream; said stream writing unit comprising stream attribute decision means for deciding whether or not each audio data stream has been subjected to the data conversion process for digital audio data, and stream writing means for attaching a respective conversion ID flag having a value indicating the result of the decision of said stream attribute decision means to each audio data stream, and for writing a flag-attached audio data stream for each audio data stream into said stream storage unit; and said stream reading unit comprising stream reading means for reading the flag-attached audio data stream from said stream storage unit, data converting means for subjecting the read flag-attached audio data stream to an inverse conversion process which is inverse to the data conversion process that the read flag-attached audio data stream has been subjected to when the conversion ID flag of the read flag-attached audio data stream indicates that the read flag-attached audio data stream is a stream which has been subjected to the data conversion process and outputting the read flag-attached audio data stream after being subjected to the inverse conversion process, and for outputting the read flag-attached audio data stream without performing the inverse conversion process when the conversion ID flag of the read flag-attached audio data stream indicates that the read flag-attached audio data stream is a stream which has not been subjected to the data conversion process, and watermarking means for inserting a watermark in the flag-attached audio data stream which is outputted by said data converting means.