Patent ID: 6490683
Filing Date: 2002-12-03
Classification: G11B

Abstract:
A data reproduction method for reproducing data made up of a plurality of error correction code blocks, each of the error correction code blocks including block data, inner parity code (PI) data serving as error correction data, and outer parity code (PO) data, each of the error correction code blocks having a plurality of electronic watermark information data, said method comprising:extracting the electronic watermark information data, based on positional information data that represents where the electronic watermark information data is recorded in each of the error corrections code blocks; and checking through data included in one error correction code block by use of the inner parity code data, the outer parity code data and the block data, performing error correction processing on the data included said one error correction code block, and sequentially continuing checking through data with respect to each of the error correction code blocks by use of the inner parity code data, the outer parity code data and the block data, said electronic watermark information data being regarded as an error and subject to error correction, wherein said electronic watermark information data (a-p) of each of the error correction code blocks is randomly arranged in at least one of said block data, inner parity code (PI) data, and outer parity code (PO) data, and said electronic watermark information data (a-p) includes error correction code.