Scrambling apparatus and descrambling apparatus.

摘要

A scrambling apparatus has at least one of following processing units: a signal inserting processor (2, 3, 4) for inserting a dummy pattern indicating the quantization width in the compressed video data; a conversion processor (50, 5) for scrambling a signal specifying whether field or frame processing is used; a DCT coefficient conversion processor (48, 7, 6) for scrambling a part of the code defining the DCT coefficient; an intra_dc_precision conversion processor (47, 5) for scrambling the intra_dc_precision signal; and an alternate_scan conversion processor (49, 5) for scrambling the alternate_scan signal. A descrambling apparatus reverses the conversion process on the video data scrambled by the scrambling apparatus to restore the video data to the original unscrambled state. <IMAGE>