Digital signal recording and reproducing apparatus and error-correcting apparatus

摘要

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 K1 symbols and a block of K2 symbols, the block of K1 symbols being further encoded with a second error-correcting code Cm and appended with m1 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.