To be fast or making slow the packing it does

摘要

PPROBLEM TO BE SOLVED: To enable easily reproducing a plurality of sync blocks with respect to the same block in pairs at the time of variable speed reproduction. PSOLUTION: For example, compression-coded data for each macroblock of 16×16 pixels are packed into two sync blocks Sd and Sh. When compression coding using quadrature modulation such as DCT is performed, the sync block Sd includes the coefficient of a low frequency region including a DC coefficient and is used when it is solely reproduced at the time of variable speed reproduction. On the other hand, the sync block Sh includes the coefficient of a high frequency region and cannot be used when it is solely reproduced at the time of the variable speed reproduction. The sync blocks Sd and Sh with respect to the same block are continuously recorded on inclined tracks of a tape. When performing variable speed reproduction, a reproducing head scans the tape across the plurality of inclined tracks. By recording the sync blocks Sd and Sh continuously, these sync blocks Sd, Sh can be easily reproduced in pairs, and image quality can be improved. PCOPYRIGHT: (C)2005,JPO&NCIPI