| 摘要 |
PROBLEM TO BE SOLVED: To apply scrambling/descrambling processing to an analog audio signal outputted from a video reproduction device without losing continuity of the signals. SOLUTION: A timing control circuit 3 generates A/D and D/A sampling clocks S1, S2 and a system block C1 synchronized with a vertical synchronizing signal VL. An analog audio signal A1 is given to an A/D converter circuit 4, in which the signal is converted into a digital audio signal and the resulting signal is given to a scramble circuit 5 where the signal data are rearranged at a fixed time width interval and a D/A converter circuit 10 is used to convert the scrambled data signal into an analog audio signal A2. Furthermore, a zero cross detector 7 decides optimum rearrangement time TZ of data so as not to cause discontinuous period for the analog signal, and then the continuity of the analog signal is ensured by using a data number control circuit 8 so as to store a pre-state value and to delete the data based on a difference between the time and the fixed time width interval TB. |
