Abstract: According to a first aspect of the invention, digital image data are recorded in the form of compressed codewords with check information and flags. The flags indicate codewords containing uncorrected errors. Each time the data are copied, error detection and correction are performed and the flags are updated to indicate any new uncorrectable errors that are detected. The flags can be used for error concealment, to avoid error miscorrection, and to permit the check information to be regenerated each time the data are copied. According to a second aspect of the invention, when image data are copied, the same check information is used to perform error detection and correction twice. Flags identifying uncorrected errors can be transferred from the first error-detecting-and-correcting process to the second.

Abstract: According to a first aspect of the invention, digital image data are recorded in the form of compressed codewords with check information and flags. The flags indicate codewords containing uncorrected errors. Each time the data are copied, error detection and correction are performed and the flags are updated to indicate any new uncorrectable errors that are detected. The flags can be used for error concealment, to avoid error miscorrection, and to permit the check information to be regenerated each time the data are copied. According to a second aspect of the invention, when image data are copied, the same check information is used to perform error detection and correction twice. Flags identifying uncorrected errors can be transferred from the first error-detecting-and-correcting process to the second.

Abstract: Fast speed playback is performed with a reduced error-correcting capability as compared with that for normal speed playback. Information of K symbols is encoded with a first error-correcting code C1 and appended with (N-K) check symbols. After that, m symbols out of the check symbols are punctured, and the information of K symbols is divided into a block of K.sub.1 symbols and a block of K.sub.2 symbols, the block of K.sub.1 symbols being further encoded with a second error-correcting code Cm and appended with m.sub.1 check symbols for error correction. For efficient error-correction coding of auxiliary data which is usually not used but which becomes necessary on occasions, the presence or absence of auxiliary data is written in ID information, and the number of error-correcting check symbols is changed accordingly.